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Diffstat (limited to 'arch/m68k/ifpsp060/src/pfpsp.S')
| -rw-r--r-- | arch/m68k/ifpsp060/src/pfpsp.S | 14745 |
1 files changed, 14745 insertions, 0 deletions
diff --git a/arch/m68k/ifpsp060/src/pfpsp.S b/arch/m68k/ifpsp060/src/pfpsp.S new file mode 100644 index 000000000..3535e6c87 --- /dev/null +++ b/arch/m68k/ifpsp060/src/pfpsp.S @@ -0,0 +1,14745 @@ +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP +M68000 Hi-Performance Microprocessor Division +M68060 Software Package +Production Release P1.00 -- October 10, 1994 + +M68060 Software Package Copyright © 1993, 1994 Motorola Inc. All rights reserved. + +THE SOFTWARE is provided on an "AS IS" basis and without warranty. +To the maximum extent permitted by applicable law, +MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED, +INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE +and any warranty against infringement with regard to the SOFTWARE +(INCLUDING ANY MODIFIED VERSIONS THEREOF) and any accompanying written materials. + +To the maximum extent permitted by applicable law, +IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER +(INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS, +BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR OTHER PECUNIARY LOSS) +ARISING OF THE USE OR INABILITY TO USE THE SOFTWARE. +Motorola assumes no responsibility for the maintenance and support of the SOFTWARE. + +You are hereby granted a copyright license to use, modify, and distribute the SOFTWARE +so long as this entire notice is retained without alteration in any modified and/or +redistributed versions, and that such modified versions are clearly identified as such. +No licenses are granted by implication, estoppel or otherwise under any patents +or trademarks of Motorola, Inc. +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +# freal.s: +# This file is appended to the top of the 060FPSP package +# and contains the entry points into the package. The user, in +# effect, branches to one of the branch table entries located +# after _060FPSP_TABLE. +# Also, subroutine stubs exist in this file (_fpsp_done for +# example) that are referenced by the FPSP package itself in order +# to call a given routine. The stub routine actually performs the +# callout. The FPSP code does a "bsr" to the stub routine. This +# extra layer of hierarchy adds a slight performance penalty but +# it makes the FPSP code easier to read and more mainatinable. +# + +set _off_bsun, 0x00 +set _off_snan, 0x04 +set _off_operr, 0x08 +set _off_ovfl, 0x0c +set _off_unfl, 0x10 +set _off_dz, 0x14 +set _off_inex, 0x18 +set _off_fline, 0x1c +set _off_fpu_dis, 0x20 +set _off_trap, 0x24 +set _off_trace, 0x28 +set _off_access, 0x2c +set _off_done, 0x30 + +set _off_imr, 0x40 +set _off_dmr, 0x44 +set _off_dmw, 0x48 +set _off_irw, 0x4c +set _off_irl, 0x50 +set _off_drb, 0x54 +set _off_drw, 0x58 +set _off_drl, 0x5c +set _off_dwb, 0x60 +set _off_dww, 0x64 +set _off_dwl, 0x68 + +_060FPSP_TABLE: + +############################################################### + +# Here's the table of ENTRY POINTS for those linking the package. + bra.l _fpsp_snan + short 0x0000 + bra.l _fpsp_operr + short 0x0000 + bra.l _fpsp_ovfl + short 0x0000 + bra.l _fpsp_unfl + short 0x0000 + bra.l _fpsp_dz + short 0x0000 + bra.l _fpsp_inex + short 0x0000 + bra.l _fpsp_fline + short 0x0000 + bra.l _fpsp_unsupp + short 0x0000 + bra.l _fpsp_effadd + short 0x0000 + + space 56 + +############################################################### + global _fpsp_done +_fpsp_done: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_done,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_ovfl +_real_ovfl: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_ovfl,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_unfl +_real_unfl: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_unfl,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_inex +_real_inex: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_inex,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_bsun +_real_bsun: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_bsun,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_operr +_real_operr: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_operr,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_snan +_real_snan: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_snan,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_dz +_real_dz: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_dz,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_fline +_real_fline: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_fline,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_fpu_disabled +_real_fpu_disabled: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_fpu_dis,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_trap +_real_trap: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_trap,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_trace +_real_trace: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_trace,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _real_access +_real_access: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_access,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + +####################################### + + global _imem_read +_imem_read: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_imr,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _dmem_read +_dmem_read: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_dmr,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _dmem_write +_dmem_write: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_dmw,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _imem_read_word +_imem_read_word: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_irw,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _imem_read_long +_imem_read_long: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_irl,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _dmem_read_byte +_dmem_read_byte: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_drb,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _dmem_read_word +_dmem_read_word: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_drw,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _dmem_read_long +_dmem_read_long: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_drl,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _dmem_write_byte +_dmem_write_byte: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_dwb,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _dmem_write_word +_dmem_write_word: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_dww,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + + global _dmem_write_long +_dmem_write_long: + mov.l %d0,-(%sp) + mov.l (_060FPSP_TABLE-0x80+_off_dwl,%pc),%d0 + pea.l (_060FPSP_TABLE-0x80,%pc,%d0) + mov.l 0x4(%sp),%d0 + rtd &0x4 + +# +# This file contains a set of define statements for constants +# in order to promote readability within the corecode itself. +# + +set LOCAL_SIZE, 192 # stack frame size(bytes) +set LV, -LOCAL_SIZE # stack offset + +set EXC_SR, 0x4 # stack status register +set EXC_PC, 0x6 # stack pc +set EXC_VOFF, 0xa # stacked vector offset +set EXC_EA, 0xc # stacked <ea> + +set EXC_FP, 0x0 # frame pointer + +set EXC_AREGS, -68 # offset of all address regs +set EXC_DREGS, -100 # offset of all data regs +set EXC_FPREGS, -36 # offset of all fp regs + +set EXC_A7, EXC_AREGS+(7*4) # offset of saved a7 +set OLD_A7, EXC_AREGS+(6*4) # extra copy of saved a7 +set EXC_A6, EXC_AREGS+(6*4) # offset of saved a6 +set EXC_A5, EXC_AREGS+(5*4) +set EXC_A4, EXC_AREGS+(4*4) +set EXC_A3, EXC_AREGS+(3*4) +set EXC_A2, EXC_AREGS+(2*4) +set EXC_A1, EXC_AREGS+(1*4) +set EXC_A0, EXC_AREGS+(0*4) +set EXC_D7, EXC_DREGS+(7*4) +set EXC_D6, EXC_DREGS+(6*4) +set EXC_D5, EXC_DREGS+(5*4) +set EXC_D4, EXC_DREGS+(4*4) +set EXC_D3, EXC_DREGS+(3*4) +set EXC_D2, EXC_DREGS+(2*4) +set EXC_D1, EXC_DREGS+(1*4) +set EXC_D0, EXC_DREGS+(0*4) + +set EXC_FP0, EXC_FPREGS+(0*12) # offset of saved fp0 +set EXC_FP1, EXC_FPREGS+(1*12) # offset of saved fp1 +set EXC_FP2, EXC_FPREGS+(2*12) # offset of saved fp2 (not used) + +set FP_SCR1, LV+80 # fp scratch 1 +set FP_SCR1_EX, FP_SCR1+0 +set FP_SCR1_SGN, FP_SCR1+2 +set FP_SCR1_HI, FP_SCR1+4 +set FP_SCR1_LO, FP_SCR1+8 + +set FP_SCR0, LV+68 # fp scratch 0 +set FP_SCR0_EX, FP_SCR0+0 +set FP_SCR0_SGN, FP_SCR0+2 +set FP_SCR0_HI, FP_SCR0+4 +set FP_SCR0_LO, FP_SCR0+8 + +set FP_DST, LV+56 # fp destination operand +set FP_DST_EX, FP_DST+0 +set FP_DST_SGN, FP_DST+2 +set FP_DST_HI, FP_DST+4 +set FP_DST_LO, FP_DST+8 + +set FP_SRC, LV+44 # fp source operand +set FP_SRC_EX, FP_SRC+0 +set FP_SRC_SGN, FP_SRC+2 +set FP_SRC_HI, FP_SRC+4 +set FP_SRC_LO, FP_SRC+8 + +set USER_FPIAR, LV+40 # FP instr address register + +set USER_FPSR, LV+36 # FP status register +set FPSR_CC, USER_FPSR+0 # FPSR condition codes +set FPSR_QBYTE, USER_FPSR+1 # FPSR qoutient byte +set FPSR_EXCEPT, USER_FPSR+2 # FPSR exception status byte +set FPSR_AEXCEPT, USER_FPSR+3 # FPSR accrued exception byte + +set USER_FPCR, LV+32 # FP control register +set FPCR_ENABLE, USER_FPCR+2 # FPCR exception enable +set FPCR_MODE, USER_FPCR+3 # FPCR rounding mode control + +set L_SCR3, LV+28 # integer scratch 3 +set L_SCR2, LV+24 # integer scratch 2 +set L_SCR1, LV+20 # integer scratch 1 + +set STORE_FLG, LV+19 # flag: operand store (ie. not fcmp/ftst) + +set EXC_TEMP2, LV+24 # temporary space +set EXC_TEMP, LV+16 # temporary space + +set DTAG, LV+15 # destination operand type +set STAG, LV+14 # source operand type + +set SPCOND_FLG, LV+10 # flag: special case (see below) + +set EXC_CC, LV+8 # saved condition codes +set EXC_EXTWPTR, LV+4 # saved current PC (active) +set EXC_EXTWORD, LV+2 # saved extension word +set EXC_CMDREG, LV+2 # saved extension word +set EXC_OPWORD, LV+0 # saved operation word + +################################ + +# Helpful macros + +set FTEMP, 0 # offsets within an +set FTEMP_EX, 0 # extended precision +set FTEMP_SGN, 2 # value saved in memory. +set FTEMP_HI, 4 +set FTEMP_LO, 8 +set FTEMP_GRS, 12 + +set LOCAL, 0 # offsets within an +set LOCAL_EX, 0 # extended precision +set LOCAL_SGN, 2 # value saved in memory. +set LOCAL_HI, 4 +set LOCAL_LO, 8 +set LOCAL_GRS, 12 + +set DST, 0 # offsets within an +set DST_EX, 0 # extended precision +set DST_HI, 4 # value saved in memory. +set DST_LO, 8 + +set SRC, 0 # offsets within an +set SRC_EX, 0 # extended precision +set SRC_HI, 4 # value saved in memory. +set SRC_LO, 8 + +set SGL_LO, 0x3f81 # min sgl prec exponent +set SGL_HI, 0x407e # max sgl prec exponent +set DBL_LO, 0x3c01 # min dbl prec exponent +set DBL_HI, 0x43fe # max dbl prec exponent +set EXT_LO, 0x0 # min ext prec exponent +set EXT_HI, 0x7ffe # max ext prec exponent + +set EXT_BIAS, 0x3fff # extended precision bias +set SGL_BIAS, 0x007f # single precision bias +set DBL_BIAS, 0x03ff # double precision bias + +set NORM, 0x00 # operand type for STAG/DTAG +set ZERO, 0x01 # operand type for STAG/DTAG +set INF, 0x02 # operand type for STAG/DTAG +set QNAN, 0x03 # operand type for STAG/DTAG +set DENORM, 0x04 # operand type for STAG/DTAG +set SNAN, 0x05 # operand type for STAG/DTAG +set UNNORM, 0x06 # operand type for STAG/DTAG + +################## +# FPSR/FPCR bits # +################## +set neg_bit, 0x3 # negative result +set z_bit, 0x2 # zero result +set inf_bit, 0x1 # infinite result +set nan_bit, 0x0 # NAN result + +set q_sn_bit, 0x7 # sign bit of quotient byte + +set bsun_bit, 7 # branch on unordered +set snan_bit, 6 # signalling NAN +set operr_bit, 5 # operand error +set ovfl_bit, 4 # overflow +set unfl_bit, 3 # underflow +set dz_bit, 2 # divide by zero +set inex2_bit, 1 # inexact result 2 +set inex1_bit, 0 # inexact result 1 + +set aiop_bit, 7 # accrued inexact operation bit +set aovfl_bit, 6 # accrued overflow bit +set aunfl_bit, 5 # accrued underflow bit +set adz_bit, 4 # accrued dz bit +set ainex_bit, 3 # accrued inexact bit + +############################# +# FPSR individual bit masks # +############################# +set neg_mask, 0x08000000 # negative bit mask (lw) +set inf_mask, 0x02000000 # infinity bit mask (lw) +set z_mask, 0x04000000 # zero bit mask (lw) +set nan_mask, 0x01000000 # nan bit mask (lw) + +set neg_bmask, 0x08 # negative bit mask (byte) +set inf_bmask, 0x02 # infinity bit mask (byte) +set z_bmask, 0x04 # zero bit mask (byte) +set nan_bmask, 0x01 # nan bit mask (byte) + +set bsun_mask, 0x00008000 # bsun exception mask +set snan_mask, 0x00004000 # snan exception mask +set operr_mask, 0x00002000 # operr exception mask +set ovfl_mask, 0x00001000 # overflow exception mask +set unfl_mask, 0x00000800 # underflow exception mask +set dz_mask, 0x00000400 # dz exception mask +set inex2_mask, 0x00000200 # inex2 exception mask +set inex1_mask, 0x00000100 # inex1 exception mask + +set aiop_mask, 0x00000080 # accrued illegal operation +set aovfl_mask, 0x00000040 # accrued overflow +set aunfl_mask, 0x00000020 # accrued underflow +set adz_mask, 0x00000010 # accrued divide by zero +set ainex_mask, 0x00000008 # accrued inexact + +###################################### +# FPSR combinations used in the FPSP # +###################################### +set dzinf_mask, inf_mask+dz_mask+adz_mask +set opnan_mask, nan_mask+operr_mask+aiop_mask +set nzi_mask, 0x01ffffff #clears N, Z, and I +set unfinx_mask, unfl_mask+inex2_mask+aunfl_mask+ainex_mask +set unf2inx_mask, unfl_mask+inex2_mask+ainex_mask +set ovfinx_mask, ovfl_mask+inex2_mask+aovfl_mask+ainex_mask +set inx1a_mask, inex1_mask+ainex_mask +set inx2a_mask, inex2_mask+ainex_mask +set snaniop_mask, nan_mask+snan_mask+aiop_mask +set snaniop2_mask, snan_mask+aiop_mask +set naniop_mask, nan_mask+aiop_mask +set neginf_mask, neg_mask+inf_mask +set infaiop_mask, inf_mask+aiop_mask +set negz_mask, neg_mask+z_mask +set opaop_mask, operr_mask+aiop_mask +set unfl_inx_mask, unfl_mask+aunfl_mask+ainex_mask +set ovfl_inx_mask, ovfl_mask+aovfl_mask+ainex_mask + +######### +# misc. # +######### +set rnd_stky_bit, 29 # stky bit pos in longword + +set sign_bit, 0x7 # sign bit +set signan_bit, 0x6 # signalling nan bit + +set sgl_thresh, 0x3f81 # minimum sgl exponent +set dbl_thresh, 0x3c01 # minimum dbl exponent + +set x_mode, 0x0 # extended precision +set s_mode, 0x4 # single precision +set d_mode, 0x8 # double precision + +set rn_mode, 0x0 # round-to-nearest +set rz_mode, 0x1 # round-to-zero +set rm_mode, 0x2 # round-tp-minus-infinity +set rp_mode, 0x3 # round-to-plus-infinity + +set mantissalen, 64 # length of mantissa in bits + +set BYTE, 1 # len(byte) == 1 byte +set WORD, 2 # len(word) == 2 bytes +set LONG, 4 # len(longword) == 2 bytes + +set BSUN_VEC, 0xc0 # bsun vector offset +set INEX_VEC, 0xc4 # inexact vector offset +set DZ_VEC, 0xc8 # dz vector offset +set UNFL_VEC, 0xcc # unfl vector offset +set OPERR_VEC, 0xd0 # operr vector offset +set OVFL_VEC, 0xd4 # ovfl vector offset +set SNAN_VEC, 0xd8 # snan vector offset + +########################### +# SPecial CONDition FLaGs # +########################### +set ftrapcc_flg, 0x01 # flag bit: ftrapcc exception +set fbsun_flg, 0x02 # flag bit: bsun exception +set mia7_flg, 0x04 # flag bit: (a7)+ <ea> +set mda7_flg, 0x08 # flag bit: -(a7) <ea> +set fmovm_flg, 0x40 # flag bit: fmovm instruction +set immed_flg, 0x80 # flag bit: &<data> <ea> + +set ftrapcc_bit, 0x0 +set fbsun_bit, 0x1 +set mia7_bit, 0x2 +set mda7_bit, 0x3 +set immed_bit, 0x7 + +################################## +# TRANSCENDENTAL "LAST-OP" FLAGS # +################################## +set FMUL_OP, 0x0 # fmul instr performed last +set FDIV_OP, 0x1 # fdiv performed last +set FADD_OP, 0x2 # fadd performed last +set FMOV_OP, 0x3 # fmov performed last + +############# +# CONSTANTS # +############# +T1: long 0x40C62D38,0xD3D64634 # 16381 LOG2 LEAD +T2: long 0x3D6F90AE,0xB1E75CC7 # 16381 LOG2 TRAIL + +PI: long 0x40000000,0xC90FDAA2,0x2168C235,0x00000000 +PIBY2: long 0x3FFF0000,0xC90FDAA2,0x2168C235,0x00000000 + +TWOBYPI: + long 0x3FE45F30,0x6DC9C883 + +######################################################################### +# XDEF **************************************************************** # +# _fpsp_ovfl(): 060FPSP entry point for FP Overflow exception. # +# # +# This handler should be the first code executed upon taking the # +# FP Overflow exception in an operating system. # +# # +# XREF **************************************************************** # +# _imem_read_long() - read instruction longword # +# fix_skewed_ops() - adjust src operand in fsave frame # +# set_tag_x() - determine optype of src/dst operands # +# store_fpreg() - store opclass 0 or 2 result to FP regfile # +# unnorm_fix() - change UNNORM operands to NORM or ZERO # +# load_fpn2() - load dst operand from FP regfile # +# fout() - emulate an opclass 3 instruction # +# tbl_unsupp - add of table of emulation routines for opclass 0,2 # +# _fpsp_done() - "callout" for 060FPSP exit (all work done!) # +# _real_ovfl() - "callout" for Overflow exception enabled code # +# _real_inex() - "callout" for Inexact exception enabled code # +# _real_trace() - "callout" for Trace exception code # +# # +# INPUT *************************************************************** # +# - The system stack contains the FP Ovfl exception stack frame # +# - The fsave frame contains the source operand # +# # +# OUTPUT ************************************************************** # +# Overflow Exception enabled: # +# - The system stack is unchanged # +# - The fsave frame contains the adjusted src op for opclass 0,2 # +# Overflow Exception disabled: # +# - The system stack is unchanged # +# - The "exception present" flag in the fsave frame is cleared # +# # +# ALGORITHM *********************************************************** # +# On the 060, if an FP overflow is present as the result of any # +# instruction, the 060 will take an overflow exception whether the # +# exception is enabled or disabled in the FPCR. For the disabled case, # +# This handler emulates the instruction to determine what the correct # +# default result should be for the operation. This default result is # +# then stored in either the FP regfile, data regfile, or memory. # +# Finally, the handler exits through the "callout" _fpsp_done() # +# denoting that no exceptional conditions exist within the machine. # +# If the exception is enabled, then this handler must create the # +# exceptional operand and plave it in the fsave state frame, and store # +# the default result (only if the instruction is opclass 3). For # +# exceptions enabled, this handler must exit through the "callout" # +# _real_ovfl() so that the operating system enabled overflow handler # +# can handle this case. # +# Two other conditions exist. First, if overflow was disabled # +# but the inexact exception was enabled, this handler must exit # +# through the "callout" _real_inex() regardless of whether the result # +# was inexact. # +# Also, in the case of an opclass three instruction where # +# overflow was disabled and the trace exception was enabled, this # +# handler must exit through the "callout" _real_trace(). # +# # +######################################################################### + + global _fpsp_ovfl +_fpsp_ovfl: + +#$# sub.l &24,%sp # make room for src/dst + + link.w %a6,&-LOCAL_SIZE # init stack frame + + fsave FP_SRC(%a6) # grab the "busy" frame + + movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 + fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs + fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack + +# the FPIAR holds the "current PC" of the faulting instruction + mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch the instruction words + mov.l %d0,EXC_OPWORD(%a6) + +############################################################################## + + btst &0x5,EXC_CMDREG(%a6) # is instr an fmove out? + bne.w fovfl_out + + + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l fix_skewed_ops # fix src op + +# since, I believe, only NORMs and DENORMs can come through here, +# maybe we can avoid the subroutine call. + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l set_tag_x # tag the operand type + mov.b %d0,STAG(%a6) # maybe NORM,DENORM + +# bit five of the fp extension word separates the monadic and dyadic operations +# that can pass through fpsp_ovfl(). remember that fcmp, ftst, and fsincos +# will never take this exception. + btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? + beq.b fovfl_extract # monadic + + bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg + bsr.l load_fpn2 # load dst into FP_DST + + lea FP_DST(%a6),%a0 # pass: ptr to dst op + bsr.l set_tag_x # tag the operand type + cmpi.b %d0,&UNNORM # is operand an UNNORM? + bne.b fovfl_op2_done # no + bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO +fovfl_op2_done: + mov.b %d0,DTAG(%a6) # save dst optype tag + +fovfl_extract: + +#$# mov.l FP_SRC_EX(%a6),TRAP_SRCOP_EX(%a6) +#$# mov.l FP_SRC_HI(%a6),TRAP_SRCOP_HI(%a6) +#$# mov.l FP_SRC_LO(%a6),TRAP_SRCOP_LO(%a6) +#$# mov.l FP_DST_EX(%a6),TRAP_DSTOP_EX(%a6) +#$# mov.l FP_DST_HI(%a6),TRAP_DSTOP_HI(%a6) +#$# mov.l FP_DST_LO(%a6),TRAP_DSTOP_LO(%a6) + + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode + + mov.b 1+EXC_CMDREG(%a6),%d1 + andi.w &0x007f,%d1 # extract extension + + andi.l &0x00ff01ff,USER_FPSR(%a6) # zero all but accured field + + fmov.l &0x0,%fpcr # zero current control regs + fmov.l &0x0,%fpsr + + lea FP_SRC(%a6),%a0 + lea FP_DST(%a6),%a1 + +# maybe we can make these entry points ONLY the OVFL entry points of each routine. + mov.l (tbl_unsupp.l,%pc,%d1.w*4),%d1 # fetch routine addr + jsr (tbl_unsupp.l,%pc,%d1.l*1) + +# the operation has been emulated. the result is in fp0. +# the EXOP, if an exception occurred, is in fp1. +# we must save the default result regardless of whether +# traps are enabled or disabled. + bfextu EXC_CMDREG(%a6){&6:&3},%d0 + bsr.l store_fpreg + +# the exceptional possibilities we have left ourselves with are ONLY overflow +# and inexact. and, the inexact is such that overflow occurred and was disabled +# but inexact was enabled. + btst &ovfl_bit,FPCR_ENABLE(%a6) + bne.b fovfl_ovfl_on + + btst &inex2_bit,FPCR_ENABLE(%a6) + bne.b fovfl_inex_on + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 +#$# add.l &24,%sp + bra.l _fpsp_done + +# overflow is enabled AND overflow, of course, occurred. so, we have the EXOP +# in fp1. now, simply jump to _real_ovfl()! +fovfl_ovfl_on: + fmovm.x &0x40,FP_SRC(%a6) # save EXOP (fp1) to stack + + mov.w &0xe005,2+FP_SRC(%a6) # save exc status + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) # do this after fmovm,other f<op>s! + + unlk %a6 + + bra.l _real_ovfl + +# overflow occurred but is disabled. meanwhile, inexact is enabled. Therefore, +# we must jump to real_inex(). +fovfl_inex_on: + + fmovm.x &0x40,FP_SRC(%a6) # save EXOP (fp1) to stack + + mov.b &0xc4,1+EXC_VOFF(%a6) # vector offset = 0xc4 + mov.w &0xe001,2+FP_SRC(%a6) # save exc status + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) # do this after fmovm,other f<op>s! + + unlk %a6 + + bra.l _real_inex + +######################################################################## +fovfl_out: + + +#$# mov.l FP_SRC_EX(%a6),TRAP_SRCOP_EX(%a6) +#$# mov.l FP_SRC_HI(%a6),TRAP_SRCOP_HI(%a6) +#$# mov.l FP_SRC_LO(%a6),TRAP_SRCOP_LO(%a6) + +# the src operand is definitely a NORM(!), so tag it as such + mov.b &NORM,STAG(%a6) # set src optype tag + + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode + + and.l &0xffff00ff,USER_FPSR(%a6) # zero all but accured field + + fmov.l &0x0,%fpcr # zero current control regs + fmov.l &0x0,%fpsr + + lea FP_SRC(%a6),%a0 # pass ptr to src operand + + bsr.l fout + + btst &ovfl_bit,FPCR_ENABLE(%a6) + bne.w fovfl_ovfl_on + + btst &inex2_bit,FPCR_ENABLE(%a6) + bne.w fovfl_inex_on + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 +#$# add.l &24,%sp + + btst &0x7,(%sp) # is trace on? + beq.l _fpsp_done # no + + fmov.l %fpiar,0x8(%sp) # "Current PC" is in FPIAR + mov.w &0x2024,0x6(%sp) # stk fmt = 0x2; voff = 0x024 + bra.l _real_trace + +######################################################################### +# XDEF **************************************************************** # +# _fpsp_unfl(): 060FPSP entry point for FP Underflow exception. # +# # +# This handler should be the first code executed upon taking the # +# FP Underflow exception in an operating system. # +# # +# XREF **************************************************************** # +# _imem_read_long() - read instruction longword # +# fix_skewed_ops() - adjust src operand in fsave frame # +# set_tag_x() - determine optype of src/dst operands # +# store_fpreg() - store opclass 0 or 2 result to FP regfile # +# unnorm_fix() - change UNNORM operands to NORM or ZERO # +# load_fpn2() - load dst operand from FP regfile # +# fout() - emulate an opclass 3 instruction # +# tbl_unsupp - add of table of emulation routines for opclass 0,2 # +# _fpsp_done() - "callout" for 060FPSP exit (all work done!) # +# _real_ovfl() - "callout" for Overflow exception enabled code # +# _real_inex() - "callout" for Inexact exception enabled code # +# _real_trace() - "callout" for Trace exception code # +# # +# INPUT *************************************************************** # +# - The system stack contains the FP Unfl exception stack frame # +# - The fsave frame contains the source operand # +# # +# OUTPUT ************************************************************** # +# Underflow Exception enabled: # +# - The system stack is unchanged # +# - The fsave frame contains the adjusted src op for opclass 0,2 # +# Underflow Exception disabled: # +# - The system stack is unchanged # +# - The "exception present" flag in the fsave frame is cleared # +# # +# ALGORITHM *********************************************************** # +# On the 060, if an FP underflow is present as the result of any # +# instruction, the 060 will take an underflow exception whether the # +# exception is enabled or disabled in the FPCR. For the disabled case, # +# This handler emulates the instruction to determine what the correct # +# default result should be for the operation. This default result is # +# then stored in either the FP regfile, data regfile, or memory. # +# Finally, the handler exits through the "callout" _fpsp_done() # +# denoting that no exceptional conditions exist within the machine. # +# If the exception is enabled, then this handler must create the # +# exceptional operand and plave it in the fsave state frame, and store # +# the default result (only if the instruction is opclass 3). For # +# exceptions enabled, this handler must exit through the "callout" # +# _real_unfl() so that the operating system enabled overflow handler # +# can handle this case. # +# Two other conditions exist. First, if underflow was disabled # +# but the inexact exception was enabled and the result was inexact, # +# this handler must exit through the "callout" _real_inex(). # +# was inexact. # +# Also, in the case of an opclass three instruction where # +# underflow was disabled and the trace exception was enabled, this # +# handler must exit through the "callout" _real_trace(). # +# # +######################################################################### + + global _fpsp_unfl +_fpsp_unfl: + +#$# sub.l &24,%sp # make room for src/dst + + link.w %a6,&-LOCAL_SIZE # init stack frame + + fsave FP_SRC(%a6) # grab the "busy" frame + + movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 + fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs + fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack + +# the FPIAR holds the "current PC" of the faulting instruction + mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch the instruction words + mov.l %d0,EXC_OPWORD(%a6) + +############################################################################## + + btst &0x5,EXC_CMDREG(%a6) # is instr an fmove out? + bne.w funfl_out + + + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l fix_skewed_ops # fix src op + + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l set_tag_x # tag the operand type + mov.b %d0,STAG(%a6) # maybe NORM,DENORM + +# bit five of the fp ext word separates the monadic and dyadic operations +# that can pass through fpsp_unfl(). remember that fcmp, and ftst +# will never take this exception. + btst &0x5,1+EXC_CMDREG(%a6) # is op monadic or dyadic? + beq.b funfl_extract # monadic + +# now, what's left that's not dyadic is fsincos. we can distinguish it +# from all dyadics by the '0110xxx pattern + btst &0x4,1+EXC_CMDREG(%a6) # is op an fsincos? + bne.b funfl_extract # yes + + bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg + bsr.l load_fpn2 # load dst into FP_DST + + lea FP_DST(%a6),%a0 # pass: ptr to dst op + bsr.l set_tag_x # tag the operand type + cmpi.b %d0,&UNNORM # is operand an UNNORM? + bne.b funfl_op2_done # no + bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO +funfl_op2_done: + mov.b %d0,DTAG(%a6) # save dst optype tag + +funfl_extract: + +#$# mov.l FP_SRC_EX(%a6),TRAP_SRCOP_EX(%a6) +#$# mov.l FP_SRC_HI(%a6),TRAP_SRCOP_HI(%a6) +#$# mov.l FP_SRC_LO(%a6),TRAP_SRCOP_LO(%a6) +#$# mov.l FP_DST_EX(%a6),TRAP_DSTOP_EX(%a6) +#$# mov.l FP_DST_HI(%a6),TRAP_DSTOP_HI(%a6) +#$# mov.l FP_DST_LO(%a6),TRAP_DSTOP_LO(%a6) + + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode + + mov.b 1+EXC_CMDREG(%a6),%d1 + andi.w &0x007f,%d1 # extract extension + + andi.l &0x00ff01ff,USER_FPSR(%a6) + + fmov.l &0x0,%fpcr # zero current control regs + fmov.l &0x0,%fpsr + + lea FP_SRC(%a6),%a0 + lea FP_DST(%a6),%a1 + +# maybe we can make these entry points ONLY the OVFL entry points of each routine. + mov.l (tbl_unsupp.l,%pc,%d1.w*4),%d1 # fetch routine addr + jsr (tbl_unsupp.l,%pc,%d1.l*1) + + bfextu EXC_CMDREG(%a6){&6:&3},%d0 + bsr.l store_fpreg + +# The `060 FPU multiplier hardware is such that if the result of a +# multiply operation is the smallest possible normalized number +# (0x00000000_80000000_00000000), then the machine will take an +# underflow exception. Since this is incorrect, we need to check +# if our emulation, after re-doing the operation, decided that +# no underflow was called for. We do these checks only in +# funfl_{unfl,inex}_on() because w/ both exceptions disabled, this +# special case will simply exit gracefully with the correct result. + +# the exceptional possibilities we have left ourselves with are ONLY overflow +# and inexact. and, the inexact is such that overflow occurred and was disabled +# but inexact was enabled. + btst &unfl_bit,FPCR_ENABLE(%a6) + bne.b funfl_unfl_on + +funfl_chkinex: + btst &inex2_bit,FPCR_ENABLE(%a6) + bne.b funfl_inex_on + +funfl_exit: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 +#$# add.l &24,%sp + bra.l _fpsp_done + +# overflow is enabled AND overflow, of course, occurred. so, we have the EXOP +# in fp1 (don't forget to save fp0). what to do now? +# well, we simply have to get to go to _real_unfl()! +funfl_unfl_on: + +# The `060 FPU multiplier hardware is such that if the result of a +# multiply operation is the smallest possible normalized number +# (0x00000000_80000000_00000000), then the machine will take an +# underflow exception. Since this is incorrect, we check here to see +# if our emulation, after re-doing the operation, decided that +# no underflow was called for. + btst &unfl_bit,FPSR_EXCEPT(%a6) + beq.w funfl_chkinex + +funfl_unfl_on2: + fmovm.x &0x40,FP_SRC(%a6) # save EXOP (fp1) to stack + + mov.w &0xe003,2+FP_SRC(%a6) # save exc status + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) # do this after fmovm,other f<op>s! + + unlk %a6 + + bra.l _real_unfl + +# underflow occurred but is disabled. meanwhile, inexact is enabled. Therefore, +# we must jump to real_inex(). +funfl_inex_on: + +# The `060 FPU multiplier hardware is such that if the result of a +# multiply operation is the smallest possible normalized number +# (0x00000000_80000000_00000000), then the machine will take an +# underflow exception. +# But, whether bogus or not, if inexact is enabled AND it occurred, +# then we have to branch to real_inex. + + btst &inex2_bit,FPSR_EXCEPT(%a6) + beq.w funfl_exit + +funfl_inex_on2: + + fmovm.x &0x40,FP_SRC(%a6) # save EXOP to stack + + mov.b &0xc4,1+EXC_VOFF(%a6) # vector offset = 0xc4 + mov.w &0xe001,2+FP_SRC(%a6) # save exc status + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) # do this after fmovm,other f<op>s! + + unlk %a6 + + bra.l _real_inex + +####################################################################### +funfl_out: + + +#$# mov.l FP_SRC_EX(%a6),TRAP_SRCOP_EX(%a6) +#$# mov.l FP_SRC_HI(%a6),TRAP_SRCOP_HI(%a6) +#$# mov.l FP_SRC_LO(%a6),TRAP_SRCOP_LO(%a6) + +# the src operand is definitely a NORM(!), so tag it as such + mov.b &NORM,STAG(%a6) # set src optype tag + + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode + + and.l &0xffff00ff,USER_FPSR(%a6) # zero all but accured field + + fmov.l &0x0,%fpcr # zero current control regs + fmov.l &0x0,%fpsr + + lea FP_SRC(%a6),%a0 # pass ptr to src operand + + bsr.l fout + + btst &unfl_bit,FPCR_ENABLE(%a6) + bne.w funfl_unfl_on2 + + btst &inex2_bit,FPCR_ENABLE(%a6) + bne.w funfl_inex_on2 + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 +#$# add.l &24,%sp + + btst &0x7,(%sp) # is trace on? + beq.l _fpsp_done # no + + fmov.l %fpiar,0x8(%sp) # "Current PC" is in FPIAR + mov.w &0x2024,0x6(%sp) # stk fmt = 0x2; voff = 0x024 + bra.l _real_trace + +######################################################################### +# XDEF **************************************************************** # +# _fpsp_unsupp(): 060FPSP entry point for FP "Unimplemented # +# Data Type" exception. # +# # +# This handler should be the first code executed upon taking the # +# FP Unimplemented Data Type exception in an operating system. # +# # +# XREF **************************************************************** # +# _imem_read_{word,long}() - read instruction word/longword # +# fix_skewed_ops() - adjust src operand in fsave frame # +# set_tag_x() - determine optype of src/dst operands # +# store_fpreg() - store opclass 0 or 2 result to FP regfile # +# unnorm_fix() - change UNNORM operands to NORM or ZERO # +# load_fpn2() - load dst operand from FP regfile # +# load_fpn1() - load src operand from FP regfile # +# fout() - emulate an opclass 3 instruction # +# tbl_unsupp - add of table of emulation routines for opclass 0,2 # +# _real_inex() - "callout" to operating system inexact handler # +# _fpsp_done() - "callout" for exit; work all done # +# _real_trace() - "callout" for Trace enabled exception # +# funimp_skew() - adjust fsave src ops to "incorrect" value # +# _real_snan() - "callout" for SNAN exception # +# _real_operr() - "callout" for OPERR exception # +# _real_ovfl() - "callout" for OVFL exception # +# _real_unfl() - "callout" for UNFL exception # +# get_packed() - fetch packed operand from memory # +# # +# INPUT *************************************************************** # +# - The system stack contains the "Unimp Data Type" stk frame # +# - The fsave frame contains the ssrc op (for UNNORM/DENORM) # +# # +# OUTPUT ************************************************************** # +# If Inexact exception (opclass 3): # +# - The system stack is changed to an Inexact exception stk frame # +# If SNAN exception (opclass 3): # +# - The system stack is changed to an SNAN exception stk frame # +# If OPERR exception (opclass 3): # +# - The system stack is changed to an OPERR exception stk frame # +# If OVFL exception (opclass 3): # +# - The system stack is changed to an OVFL exception stk frame # +# If UNFL exception (opclass 3): # +# - The system stack is changed to an UNFL exception stack frame # +# If Trace exception enabled: # +# - The system stack is changed to a Trace exception stack frame # +# Else: (normal case) # +# - Correct result has been stored as appropriate # +# # +# ALGORITHM *********************************************************** # +# Two main instruction types can enter here: (1) DENORM or UNNORM # +# unimplemented data types. These can be either opclass 0,2 or 3 # +# instructions, and (2) PACKED unimplemented data format instructions # +# also of opclasses 0,2, or 3. # +# For UNNORM/DENORM opclass 0 and 2, the handler fetches the src # +# operand from the fsave state frame and the dst operand (if dyadic) # +# from the FP register file. The instruction is then emulated by # +# choosing an emulation routine from a table of routines indexed by # +# instruction type. Once the instruction has been emulated and result # +# saved, then we check to see if any enabled exceptions resulted from # +# instruction emulation. If none, then we exit through the "callout" # +# _fpsp_done(). If there is an enabled FP exception, then we insert # +# this exception into the FPU in the fsave state frame and then exit # +# through _fpsp_done(). # +# PACKED opclass 0 and 2 is similar in how the instruction is # +# emulated and exceptions handled. The differences occur in how the # +# handler loads the packed op (by calling get_packed() routine) and # +# by the fact that a Trace exception could be pending for PACKED ops. # +# If a Trace exception is pending, then the current exception stack # +# frame is changed to a Trace exception stack frame and an exit is # +# made through _real_trace(). # +# For UNNORM/DENORM opclass 3, the actual move out to memory is # +# performed by calling the routine fout(). If no exception should occur # +# as the result of emulation, then an exit either occurs through # +# _fpsp_done() or through _real_trace() if a Trace exception is pending # +# (a Trace stack frame must be created here, too). If an FP exception # +# should occur, then we must create an exception stack frame of that # +# type and jump to either _real_snan(), _real_operr(), _real_inex(), # +# _real_unfl(), or _real_ovfl() as appropriate. PACKED opclass 3 # +# emulation is performed in a similar manner. # +# # +######################################################################### + +# +# (1) DENORM and UNNORM (unimplemented) data types: +# +# post-instruction +# ***************** +# * EA * +# pre-instruction * * +# ***************** ***************** +# * 0x0 * 0x0dc * * 0x3 * 0x0dc * +# ***************** ***************** +# * Next * * Next * +# * PC * * PC * +# ***************** ***************** +# * SR * * SR * +# ***************** ***************** +# +# (2) PACKED format (unsupported) opclasses two and three: +# ***************** +# * EA * +# * * +# ***************** +# * 0x2 * 0x0dc * +# ***************** +# * Next * +# * PC * +# ***************** +# * SR * +# ***************** +# + global _fpsp_unsupp +_fpsp_unsupp: + + link.w %a6,&-LOCAL_SIZE # init stack frame + + fsave FP_SRC(%a6) # save fp state + + movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 + fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs + fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack + + btst &0x5,EXC_SR(%a6) # user or supervisor mode? + bne.b fu_s +fu_u: + mov.l %usp,%a0 # fetch user stack pointer + mov.l %a0,EXC_A7(%a6) # save on stack + bra.b fu_cont +# if the exception is an opclass zero or two unimplemented data type +# exception, then the a7' calculated here is wrong since it doesn't +# stack an ea. however, we don't need an a7' for this case anyways. +fu_s: + lea 0x4+EXC_EA(%a6),%a0 # load old a7' + mov.l %a0,EXC_A7(%a6) # save on stack + +fu_cont: + +# the FPIAR holds the "current PC" of the faulting instruction +# the FPIAR should be set correctly for ALL exceptions passing through +# this point. + mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch the instruction words + mov.l %d0,EXC_OPWORD(%a6) # store OPWORD and EXTWORD + +############################ + + clr.b SPCOND_FLG(%a6) # clear special condition flag + +# Separate opclass three (fpn-to-mem) ops since they have a different +# stack frame and protocol. + btst &0x5,EXC_CMDREG(%a6) # is it an fmove out? + bne.w fu_out # yes + +# Separate packed opclass two instructions. + bfextu EXC_CMDREG(%a6){&0:&6},%d0 + cmpi.b %d0,&0x13 + beq.w fu_in_pack + + +# I'm not sure at this point what FPSR bits are valid for this instruction. +# so, since the emulation routines re-create them anyways, zero exception field + andi.l &0x00ff00ff,USER_FPSR(%a6) # zero exception field + + fmov.l &0x0,%fpcr # zero current control regs + fmov.l &0x0,%fpsr + +# Opclass two w/ memory-to-fpn operation will have an incorrect extended +# precision format if the src format was single or double and the +# source data type was an INF, NAN, DENORM, or UNNORM + lea FP_SRC(%a6),%a0 # pass ptr to input + bsr.l fix_skewed_ops + +# we don't know whether the src operand or the dst operand (or both) is the +# UNNORM or DENORM. call the function that tags the operand type. if the +# input is an UNNORM, then convert it to a NORM, DENORM, or ZERO. + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l set_tag_x # tag the operand type + cmpi.b %d0,&UNNORM # is operand an UNNORM? + bne.b fu_op2 # no + bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO + +fu_op2: + mov.b %d0,STAG(%a6) # save src optype tag + + bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg + +# bit five of the fp extension word separates the monadic and dyadic operations +# at this point + btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? + beq.b fu_extract # monadic + cmpi.b 1+EXC_CMDREG(%a6),&0x3a # is operation an ftst? + beq.b fu_extract # yes, so it's monadic, too + + bsr.l load_fpn2 # load dst into FP_DST + + lea FP_DST(%a6),%a0 # pass: ptr to dst op + bsr.l set_tag_x # tag the operand type + cmpi.b %d0,&UNNORM # is operand an UNNORM? + bne.b fu_op2_done # no + bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO +fu_op2_done: + mov.b %d0,DTAG(%a6) # save dst optype tag + +fu_extract: + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # fetch rnd mode/prec + + bfextu 1+EXC_CMDREG(%a6){&1:&7},%d1 # extract extension + + lea FP_SRC(%a6),%a0 + lea FP_DST(%a6),%a1 + + mov.l (tbl_unsupp.l,%pc,%d1.l*4),%d1 # fetch routine addr + jsr (tbl_unsupp.l,%pc,%d1.l*1) + +# +# Exceptions in order of precedence: +# BSUN : none +# SNAN : all dyadic ops +# OPERR : fsqrt(-NORM) +# OVFL : all except ftst,fcmp +# UNFL : all except ftst,fcmp +# DZ : fdiv +# INEX2 : all except ftst,fcmp +# INEX1 : none (packed doesn't go through here) +# + +# we determine the highest priority exception(if any) set by the +# emulation routine that has also been enabled by the user. + mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions set + bne.b fu_in_ena # some are enabled + +fu_in_cont: +# fcmp and ftst do not store any result. + mov.b 1+EXC_CMDREG(%a6),%d0 # fetch extension + andi.b &0x38,%d0 # extract bits 3-5 + cmpi.b %d0,&0x38 # is instr fcmp or ftst? + beq.b fu_in_exit # yes + + bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg + bsr.l store_fpreg # store the result + +fu_in_exit: + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 + + bra.l _fpsp_done + +fu_in_ena: + and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enabled + bfffo %d0{&24:&8},%d0 # find highest priority exception + bne.b fu_in_exc # there is at least one set + +# +# No exceptions occurred that were also enabled. Now: +# +# if (OVFL && ovfl_disabled && inexact_enabled) { +# branch to _real_inex() (even if the result was exact!); +# } else { +# save the result in the proper fp reg (unless the op is fcmp or ftst); +# return; +# } +# + btst &ovfl_bit,FPSR_EXCEPT(%a6) # was overflow set? + beq.b fu_in_cont # no + +fu_in_ovflchk: + btst &inex2_bit,FPCR_ENABLE(%a6) # was inexact enabled? + beq.b fu_in_cont # no + bra.w fu_in_exc_ovfl # go insert overflow frame + +# +# An exception occurred and that exception was enabled: +# +# shift enabled exception field into lo byte of d0; +# if (((INEX2 || INEX1) && inex_enabled && OVFL && ovfl_disabled) || +# ((INEX2 || INEX1) && inex_enabled && UNFL && unfl_disabled)) { +# /* +# * this is the case where we must call _real_inex() now or else +# * there will be no other way to pass it the exceptional operand +# */ +# call _real_inex(); +# } else { +# restore exc state (SNAN||OPERR||OVFL||UNFL||DZ||INEX) into the FPU; +# } +# +fu_in_exc: + subi.l &24,%d0 # fix offset to be 0-8 + cmpi.b %d0,&0x6 # is exception INEX? (6) + bne.b fu_in_exc_exit # no + +# the enabled exception was inexact + btst &unfl_bit,FPSR_EXCEPT(%a6) # did disabled underflow occur? + bne.w fu_in_exc_unfl # yes + btst &ovfl_bit,FPSR_EXCEPT(%a6) # did disabled overflow occur? + bne.w fu_in_exc_ovfl # yes + +# here, we insert the correct fsave status value into the fsave frame for the +# corresponding exception. the operand in the fsave frame should be the original +# src operand. +fu_in_exc_exit: + mov.l %d0,-(%sp) # save d0 + bsr.l funimp_skew # skew sgl or dbl inputs + mov.l (%sp)+,%d0 # restore d0 + + mov.w (tbl_except.b,%pc,%d0.w*2),2+FP_SRC(%a6) # create exc status + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) # restore src op + + unlk %a6 + + bra.l _fpsp_done + +tbl_except: + short 0xe000,0xe006,0xe004,0xe005 + short 0xe003,0xe002,0xe001,0xe001 + +fu_in_exc_unfl: + mov.w &0x4,%d0 + bra.b fu_in_exc_exit +fu_in_exc_ovfl: + mov.w &0x03,%d0 + bra.b fu_in_exc_exit + +# If the input operand to this operation was opclass two and a single +# or double precision denorm, inf, or nan, the operand needs to be +# "corrected" in order to have the proper equivalent extended precision +# number. + global fix_skewed_ops +fix_skewed_ops: + bfextu EXC_CMDREG(%a6){&0:&6},%d0 # extract opclass,src fmt + cmpi.b %d0,&0x11 # is class = 2 & fmt = sgl? + beq.b fso_sgl # yes + cmpi.b %d0,&0x15 # is class = 2 & fmt = dbl? + beq.b fso_dbl # yes + rts # no + +fso_sgl: + mov.w LOCAL_EX(%a0),%d0 # fetch src exponent + andi.w &0x7fff,%d0 # strip sign + cmpi.w %d0,&0x3f80 # is |exp| == $3f80? + beq.b fso_sgl_dnrm_zero # yes + cmpi.w %d0,&0x407f # no; is |exp| == $407f? + beq.b fso_infnan # yes + rts # no + +fso_sgl_dnrm_zero: + andi.l &0x7fffffff,LOCAL_HI(%a0) # clear j-bit + beq.b fso_zero # it's a skewed zero +fso_sgl_dnrm: +# here, we count on norm not to alter a0... + bsr.l norm # normalize mantissa + neg.w %d0 # -shft amt + addi.w &0x3f81,%d0 # adjust new exponent + andi.w &0x8000,LOCAL_EX(%a0) # clear old exponent + or.w %d0,LOCAL_EX(%a0) # insert new exponent + rts + +fso_zero: + andi.w &0x8000,LOCAL_EX(%a0) # clear bogus exponent + rts + +fso_infnan: + andi.b &0x7f,LOCAL_HI(%a0) # clear j-bit + ori.w &0x7fff,LOCAL_EX(%a0) # make exponent = $7fff + rts + +fso_dbl: + mov.w LOCAL_EX(%a0),%d0 # fetch src exponent + andi.w &0x7fff,%d0 # strip sign + cmpi.w %d0,&0x3c00 # is |exp| == $3c00? + beq.b fso_dbl_dnrm_zero # yes + cmpi.w %d0,&0x43ff # no; is |exp| == $43ff? + beq.b fso_infnan # yes + rts # no + +fso_dbl_dnrm_zero: + andi.l &0x7fffffff,LOCAL_HI(%a0) # clear j-bit + bne.b fso_dbl_dnrm # it's a skewed denorm + tst.l LOCAL_LO(%a0) # is it a zero? + beq.b fso_zero # yes +fso_dbl_dnrm: +# here, we count on norm not to alter a0... + bsr.l norm # normalize mantissa + neg.w %d0 # -shft amt + addi.w &0x3c01,%d0 # adjust new exponent + andi.w &0x8000,LOCAL_EX(%a0) # clear old exponent + or.w %d0,LOCAL_EX(%a0) # insert new exponent + rts + +################################################################# + +# fmove out took an unimplemented data type exception. +# the src operand is in FP_SRC. Call _fout() to write out the result and +# to determine which exceptions, if any, to take. +fu_out: + +# Separate packed move outs from the UNNORM and DENORM move outs. + bfextu EXC_CMDREG(%a6){&3:&3},%d0 + cmpi.b %d0,&0x3 + beq.w fu_out_pack + cmpi.b %d0,&0x7 + beq.w fu_out_pack + + +# I'm not sure at this point what FPSR bits are valid for this instruction. +# so, since the emulation routines re-create them anyways, zero exception field. +# fmove out doesn't affect ccodes. + and.l &0xffff00ff,USER_FPSR(%a6) # zero exception field + + fmov.l &0x0,%fpcr # zero current control regs + fmov.l &0x0,%fpsr + +# the src can ONLY be a DENORM or an UNNORM! so, don't make any big subroutine +# call here. just figure out what it is... + mov.w FP_SRC_EX(%a6),%d0 # get exponent + andi.w &0x7fff,%d0 # strip sign + beq.b fu_out_denorm # it's a DENORM + + lea FP_SRC(%a6),%a0 + bsr.l unnorm_fix # yes; fix it + + mov.b %d0,STAG(%a6) + + bra.b fu_out_cont +fu_out_denorm: + mov.b &DENORM,STAG(%a6) +fu_out_cont: + + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # fetch rnd mode/prec + + lea FP_SRC(%a6),%a0 # pass ptr to src operand + + mov.l (%a6),EXC_A6(%a6) # in case a6 changes + bsr.l fout # call fmove out routine + +# Exceptions in order of precedence: +# BSUN : none +# SNAN : none +# OPERR : fmove.{b,w,l} out of large UNNORM +# OVFL : fmove.{s,d} +# UNFL : fmove.{s,d,x} +# DZ : none +# INEX2 : all +# INEX1 : none (packed doesn't travel through here) + +# determine the highest priority exception(if any) set by the +# emulation routine that has also been enabled by the user. + mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions enabled + bne.w fu_out_ena # some are enabled + +fu_out_done: + + mov.l EXC_A6(%a6),(%a6) # in case a6 changed + +# on extended precision opclass three instructions using pre-decrement or +# post-increment addressing mode, the address register is not updated. is the +# address register was the stack pointer used from user mode, then let's update +# it here. if it was used from supervisor mode, then we have to handle this +# as a special case. + btst &0x5,EXC_SR(%a6) + bne.b fu_out_done_s + + mov.l EXC_A7(%a6),%a0 # restore a7 + mov.l %a0,%usp + +fu_out_done_cont: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 + + btst &0x7,(%sp) # is trace on? + bne.b fu_out_trace # yes + + bra.l _fpsp_done + +# is the ea mode pre-decrement of the stack pointer from supervisor mode? +# ("fmov.x fpm,-(a7)") if so, +fu_out_done_s: + cmpi.b SPCOND_FLG(%a6),&mda7_flg + bne.b fu_out_done_cont + +# the extended precision result is still in fp0. but, we need to save it +# somewhere on the stack until we can copy it to its final resting place. +# here, we're counting on the top of the stack to be the old place-holders +# for fp0/fp1 which have already been restored. that way, we can write +# over those destinations with the shifted stack frame. + fmovm.x &0x80,FP_SRC(%a6) # put answer on stack + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.l (%a6),%a6 # restore frame pointer + + mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) + mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) + +# now, copy the result to the proper place on the stack + mov.l LOCAL_SIZE+FP_SRC_EX(%sp),LOCAL_SIZE+EXC_SR+0x0(%sp) + mov.l LOCAL_SIZE+FP_SRC_HI(%sp),LOCAL_SIZE+EXC_SR+0x4(%sp) + mov.l LOCAL_SIZE+FP_SRC_LO(%sp),LOCAL_SIZE+EXC_SR+0x8(%sp) + + add.l &LOCAL_SIZE-0x8,%sp + + btst &0x7,(%sp) + bne.b fu_out_trace + + bra.l _fpsp_done + +fu_out_ena: + and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enabled + bfffo %d0{&24:&8},%d0 # find highest priority exception + bne.b fu_out_exc # there is at least one set + +# no exceptions were set. +# if a disabled overflow occurred and inexact was enabled but the result +# was exact, then a branch to _real_inex() is made. + btst &ovfl_bit,FPSR_EXCEPT(%a6) # was overflow set? + beq.w fu_out_done # no + +fu_out_ovflchk: + btst &inex2_bit,FPCR_ENABLE(%a6) # was inexact enabled? + beq.w fu_out_done # no + bra.w fu_inex # yes + +# +# The fp move out that took the "Unimplemented Data Type" exception was +# being traced. Since the stack frames are similar, get the "current" PC +# from FPIAR and put it in the trace stack frame then jump to _real_trace(). +# +# UNSUPP FRAME TRACE FRAME +# ***************** ***************** +# * EA * * Current * +# * * * PC * +# ***************** ***************** +# * 0x3 * 0x0dc * * 0x2 * 0x024 * +# ***************** ***************** +# * Next * * Next * +# * PC * * PC * +# ***************** ***************** +# * SR * * SR * +# ***************** ***************** +# +fu_out_trace: + mov.w &0x2024,0x6(%sp) + fmov.l %fpiar,0x8(%sp) + bra.l _real_trace + +# an exception occurred and that exception was enabled. +fu_out_exc: + subi.l &24,%d0 # fix offset to be 0-8 + +# we don't mess with the existing fsave frame. just re-insert it and +# jump to the "_real_{}()" handler... + mov.w (tbl_fu_out.b,%pc,%d0.w*2),%d0 + jmp (tbl_fu_out.b,%pc,%d0.w*1) + + swbeg &0x8 +tbl_fu_out: + short tbl_fu_out - tbl_fu_out # BSUN can't happen + short tbl_fu_out - tbl_fu_out # SNAN can't happen + short fu_operr - tbl_fu_out # OPERR + short fu_ovfl - tbl_fu_out # OVFL + short fu_unfl - tbl_fu_out # UNFL + short tbl_fu_out - tbl_fu_out # DZ can't happen + short fu_inex - tbl_fu_out # INEX2 + short tbl_fu_out - tbl_fu_out # INEX1 won't make it here + +# for snan,operr,ovfl,unfl, src op is still in FP_SRC so just +# frestore it. +fu_snan: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.w &0x30d8,EXC_VOFF(%a6) # vector offset = 0xd8 + mov.w &0xe006,2+FP_SRC(%a6) + + frestore FP_SRC(%a6) + + unlk %a6 + + + bra.l _real_snan + +fu_operr: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.w &0x30d0,EXC_VOFF(%a6) # vector offset = 0xd0 + mov.w &0xe004,2+FP_SRC(%a6) + + frestore FP_SRC(%a6) + + unlk %a6 + + + bra.l _real_operr + +fu_ovfl: + fmovm.x &0x40,FP_SRC(%a6) # save EXOP to the stack + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.w &0x30d4,EXC_VOFF(%a6) # vector offset = 0xd4 + mov.w &0xe005,2+FP_SRC(%a6) + + frestore FP_SRC(%a6) # restore EXOP + + unlk %a6 + + bra.l _real_ovfl + +# underflow can happen for extended precision. extended precision opclass +# three instruction exceptions don't update the stack pointer. so, if the +# exception occurred from user mode, then simply update a7 and exit normally. +# if the exception occurred from supervisor mode, check if +fu_unfl: + mov.l EXC_A6(%a6),(%a6) # restore a6 + + btst &0x5,EXC_SR(%a6) + bne.w fu_unfl_s + + mov.l EXC_A7(%a6),%a0 # restore a7 whether we need + mov.l %a0,%usp # to or not... + +fu_unfl_cont: + fmovm.x &0x40,FP_SRC(%a6) # save EXOP to the stack + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.w &0x30cc,EXC_VOFF(%a6) # vector offset = 0xcc + mov.w &0xe003,2+FP_SRC(%a6) + + frestore FP_SRC(%a6) # restore EXOP + + unlk %a6 + + bra.l _real_unfl + +fu_unfl_s: + cmpi.b SPCOND_FLG(%a6),&mda7_flg # was the <ea> mode -(sp)? + bne.b fu_unfl_cont + +# the extended precision result is still in fp0. but, we need to save it +# somewhere on the stack until we can copy it to its final resting place +# (where the exc frame is currently). make sure it's not at the top of the +# frame or it will get overwritten when the exc stack frame is shifted "down". + fmovm.x &0x80,FP_SRC(%a6) # put answer on stack + fmovm.x &0x40,FP_DST(%a6) # put EXOP on stack + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.w &0x30cc,EXC_VOFF(%a6) # vector offset = 0xcc + mov.w &0xe003,2+FP_DST(%a6) + + frestore FP_DST(%a6) # restore EXOP + + mov.l (%a6),%a6 # restore frame pointer + + mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) + mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) + mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) + +# now, copy the result to the proper place on the stack + mov.l LOCAL_SIZE+FP_SRC_EX(%sp),LOCAL_SIZE+EXC_SR+0x0(%sp) + mov.l LOCAL_SIZE+FP_SRC_HI(%sp),LOCAL_SIZE+EXC_SR+0x4(%sp) + mov.l LOCAL_SIZE+FP_SRC_LO(%sp),LOCAL_SIZE+EXC_SR+0x8(%sp) + + add.l &LOCAL_SIZE-0x8,%sp + + bra.l _real_unfl + +# fmove in and out enter here. +fu_inex: + fmovm.x &0x40,FP_SRC(%a6) # save EXOP to the stack + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.w &0x30c4,EXC_VOFF(%a6) # vector offset = 0xc4 + mov.w &0xe001,2+FP_SRC(%a6) + + frestore FP_SRC(%a6) # restore EXOP + + unlk %a6 + + + bra.l _real_inex + +######################################################################### +######################################################################### +fu_in_pack: + + +# I'm not sure at this point what FPSR bits are valid for this instruction. +# so, since the emulation routines re-create them anyways, zero exception field + andi.l &0x0ff00ff,USER_FPSR(%a6) # zero exception field + + fmov.l &0x0,%fpcr # zero current control regs + fmov.l &0x0,%fpsr + + bsr.l get_packed # fetch packed src operand + + lea FP_SRC(%a6),%a0 # pass ptr to src + bsr.l set_tag_x # set src optype tag + + mov.b %d0,STAG(%a6) # save src optype tag + + bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg + +# bit five of the fp extension word separates the monadic and dyadic operations +# at this point + btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? + beq.b fu_extract_p # monadic + cmpi.b 1+EXC_CMDREG(%a6),&0x3a # is operation an ftst? + beq.b fu_extract_p # yes, so it's monadic, too + + bsr.l load_fpn2 # load dst into FP_DST + + lea FP_DST(%a6),%a0 # pass: ptr to dst op + bsr.l set_tag_x # tag the operand type + cmpi.b %d0,&UNNORM # is operand an UNNORM? + bne.b fu_op2_done_p # no + bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO +fu_op2_done_p: + mov.b %d0,DTAG(%a6) # save dst optype tag + +fu_extract_p: + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # fetch rnd mode/prec + + bfextu 1+EXC_CMDREG(%a6){&1:&7},%d1 # extract extension + + lea FP_SRC(%a6),%a0 + lea FP_DST(%a6),%a1 + + mov.l (tbl_unsupp.l,%pc,%d1.l*4),%d1 # fetch routine addr + jsr (tbl_unsupp.l,%pc,%d1.l*1) + +# +# Exceptions in order of precedence: +# BSUN : none +# SNAN : all dyadic ops +# OPERR : fsqrt(-NORM) +# OVFL : all except ftst,fcmp +# UNFL : all except ftst,fcmp +# DZ : fdiv +# INEX2 : all except ftst,fcmp +# INEX1 : all +# + +# we determine the highest priority exception(if any) set by the +# emulation routine that has also been enabled by the user. + mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions enabled + bne.w fu_in_ena_p # some are enabled + +fu_in_cont_p: +# fcmp and ftst do not store any result. + mov.b 1+EXC_CMDREG(%a6),%d0 # fetch extension + andi.b &0x38,%d0 # extract bits 3-5 + cmpi.b %d0,&0x38 # is instr fcmp or ftst? + beq.b fu_in_exit_p # yes + + bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg + bsr.l store_fpreg # store the result + +fu_in_exit_p: + + btst &0x5,EXC_SR(%a6) # user or supervisor? + bne.w fu_in_exit_s_p # supervisor + + mov.l EXC_A7(%a6),%a0 # update user a7 + mov.l %a0,%usp + +fu_in_exit_cont_p: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 # unravel stack frame + + btst &0x7,(%sp) # is trace on? + bne.w fu_trace_p # yes + + bra.l _fpsp_done # exit to os + +# the exception occurred in supervisor mode. check to see if the +# addressing mode was (a7)+. if so, we'll need to shift the +# stack frame "up". +fu_in_exit_s_p: + btst &mia7_bit,SPCOND_FLG(%a6) # was ea mode (a7)+ + beq.b fu_in_exit_cont_p # no + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 # unravel stack frame + +# shift the stack frame "up". we don't really care about the <ea> field. + mov.l 0x4(%sp),0x10(%sp) + mov.l 0x0(%sp),0xc(%sp) + add.l &0xc,%sp + + btst &0x7,(%sp) # is trace on? + bne.w fu_trace_p # yes + + bra.l _fpsp_done # exit to os + +fu_in_ena_p: + and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enabled & set + bfffo %d0{&24:&8},%d0 # find highest priority exception + bne.b fu_in_exc_p # at least one was set + +# +# No exceptions occurred that were also enabled. Now: +# +# if (OVFL && ovfl_disabled && inexact_enabled) { +# branch to _real_inex() (even if the result was exact!); +# } else { +# save the result in the proper fp reg (unless the op is fcmp or ftst); +# return; +# } +# + btst &ovfl_bit,FPSR_EXCEPT(%a6) # was overflow set? + beq.w fu_in_cont_p # no + +fu_in_ovflchk_p: + btst &inex2_bit,FPCR_ENABLE(%a6) # was inexact enabled? + beq.w fu_in_cont_p # no + bra.w fu_in_exc_ovfl_p # do _real_inex() now + +# +# An exception occurred and that exception was enabled: +# +# shift enabled exception field into lo byte of d0; +# if (((INEX2 || INEX1) && inex_enabled && OVFL && ovfl_disabled) || +# ((INEX2 || INEX1) && inex_enabled && UNFL && unfl_disabled)) { +# /* +# * this is the case where we must call _real_inex() now or else +# * there will be no other way to pass it the exceptional operand +# */ +# call _real_inex(); +# } else { +# restore exc state (SNAN||OPERR||OVFL||UNFL||DZ||INEX) into the FPU; +# } +# +fu_in_exc_p: + subi.l &24,%d0 # fix offset to be 0-8 + cmpi.b %d0,&0x6 # is exception INEX? (6 or 7) + blt.b fu_in_exc_exit_p # no + +# the enabled exception was inexact + btst &unfl_bit,FPSR_EXCEPT(%a6) # did disabled underflow occur? + bne.w fu_in_exc_unfl_p # yes + btst &ovfl_bit,FPSR_EXCEPT(%a6) # did disabled overflow occur? + bne.w fu_in_exc_ovfl_p # yes + +# here, we insert the correct fsave status value into the fsave frame for the +# corresponding exception. the operand in the fsave frame should be the original +# src operand. +# as a reminder for future predicted pain and agony, we are passing in fsave the +# "non-skewed" operand for cases of sgl and dbl src INFs,NANs, and DENORMs. +# this is INCORRECT for enabled SNAN which would give to the user the skewed SNAN!!! +fu_in_exc_exit_p: + btst &0x5,EXC_SR(%a6) # user or supervisor? + bne.w fu_in_exc_exit_s_p # supervisor + + mov.l EXC_A7(%a6),%a0 # update user a7 + mov.l %a0,%usp + +fu_in_exc_exit_cont_p: + mov.w (tbl_except_p.b,%pc,%d0.w*2),2+FP_SRC(%a6) + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) # restore src op + + unlk %a6 + + btst &0x7,(%sp) # is trace enabled? + bne.w fu_trace_p # yes + + bra.l _fpsp_done + +tbl_except_p: + short 0xe000,0xe006,0xe004,0xe005 + short 0xe003,0xe002,0xe001,0xe001 + +fu_in_exc_ovfl_p: + mov.w &0x3,%d0 + bra.w fu_in_exc_exit_p + +fu_in_exc_unfl_p: + mov.w &0x4,%d0 + bra.w fu_in_exc_exit_p + +fu_in_exc_exit_s_p: + btst &mia7_bit,SPCOND_FLG(%a6) + beq.b fu_in_exc_exit_cont_p + + mov.w (tbl_except_p.b,%pc,%d0.w*2),2+FP_SRC(%a6) + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) # restore src op + + unlk %a6 # unravel stack frame + +# shift stack frame "up". who cares about <ea> field. + mov.l 0x4(%sp),0x10(%sp) + mov.l 0x0(%sp),0xc(%sp) + add.l &0xc,%sp + + btst &0x7,(%sp) # is trace on? + bne.b fu_trace_p # yes + + bra.l _fpsp_done # exit to os + +# +# The opclass two PACKED instruction that took an "Unimplemented Data Type" +# exception was being traced. Make the "current" PC the FPIAR and put it in the +# trace stack frame then jump to _real_trace(). +# +# UNSUPP FRAME TRACE FRAME +# ***************** ***************** +# * EA * * Current * +# * * * PC * +# ***************** ***************** +# * 0x2 * 0x0dc * * 0x2 * 0x024 * +# ***************** ***************** +# * Next * * Next * +# * PC * * PC * +# ***************** ***************** +# * SR * * SR * +# ***************** ***************** +fu_trace_p: + mov.w &0x2024,0x6(%sp) + fmov.l %fpiar,0x8(%sp) + + bra.l _real_trace + +######################################################### +######################################################### +fu_out_pack: + + +# I'm not sure at this point what FPSR bits are valid for this instruction. +# so, since the emulation routines re-create them anyways, zero exception field. +# fmove out doesn't affect ccodes. + and.l &0xffff00ff,USER_FPSR(%a6) # zero exception field + + fmov.l &0x0,%fpcr # zero current control regs + fmov.l &0x0,%fpsr + + bfextu EXC_CMDREG(%a6){&6:&3},%d0 + bsr.l load_fpn1 + +# unlike other opclass 3, unimplemented data type exceptions, packed must be +# able to detect all operand types. + lea FP_SRC(%a6),%a0 + bsr.l set_tag_x # tag the operand type + cmpi.b %d0,&UNNORM # is operand an UNNORM? + bne.b fu_op2_p # no + bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO + +fu_op2_p: + mov.b %d0,STAG(%a6) # save src optype tag + + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # fetch rnd mode/prec + + lea FP_SRC(%a6),%a0 # pass ptr to src operand + + mov.l (%a6),EXC_A6(%a6) # in case a6 changes + bsr.l fout # call fmove out routine + +# Exceptions in order of precedence: +# BSUN : no +# SNAN : yes +# OPERR : if ((k_factor > +17) || (dec. exp exceeds 3 digits)) +# OVFL : no +# UNFL : no +# DZ : no +# INEX2 : yes +# INEX1 : no + +# determine the highest priority exception(if any) set by the +# emulation routine that has also been enabled by the user. + mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions enabled + bne.w fu_out_ena_p # some are enabled + +fu_out_exit_p: + mov.l EXC_A6(%a6),(%a6) # restore a6 + + btst &0x5,EXC_SR(%a6) # user or supervisor? + bne.b fu_out_exit_s_p # supervisor + + mov.l EXC_A7(%a6),%a0 # update user a7 + mov.l %a0,%usp + +fu_out_exit_cont_p: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 # unravel stack frame + + btst &0x7,(%sp) # is trace on? + bne.w fu_trace_p # yes + + bra.l _fpsp_done # exit to os + +# the exception occurred in supervisor mode. check to see if the +# addressing mode was -(a7). if so, we'll need to shift the +# stack frame "down". +fu_out_exit_s_p: + btst &mda7_bit,SPCOND_FLG(%a6) # was ea mode -(a7) + beq.b fu_out_exit_cont_p # no + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.l (%a6),%a6 # restore frame pointer + + mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) + mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) + +# now, copy the result to the proper place on the stack + mov.l LOCAL_SIZE+FP_DST_EX(%sp),LOCAL_SIZE+EXC_SR+0x0(%sp) + mov.l LOCAL_SIZE+FP_DST_HI(%sp),LOCAL_SIZE+EXC_SR+0x4(%sp) + mov.l LOCAL_SIZE+FP_DST_LO(%sp),LOCAL_SIZE+EXC_SR+0x8(%sp) + + add.l &LOCAL_SIZE-0x8,%sp + + btst &0x7,(%sp) + bne.w fu_trace_p + + bra.l _fpsp_done + +fu_out_ena_p: + and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enabled + bfffo %d0{&24:&8},%d0 # find highest priority exception + beq.w fu_out_exit_p + + mov.l EXC_A6(%a6),(%a6) # restore a6 + +# an exception occurred and that exception was enabled. +# the only exception possible on packed move out are INEX, OPERR, and SNAN. +fu_out_exc_p: + cmpi.b %d0,&0x1a + bgt.w fu_inex_p2 + beq.w fu_operr_p + +fu_snan_p: + btst &0x5,EXC_SR(%a6) + bne.b fu_snan_s_p + + mov.l EXC_A7(%a6),%a0 + mov.l %a0,%usp + bra.w fu_snan + +fu_snan_s_p: + cmpi.b SPCOND_FLG(%a6),&mda7_flg + bne.w fu_snan + +# the instruction was "fmove.p fpn,-(a7)" from supervisor mode. +# the strategy is to move the exception frame "down" 12 bytes. then, we +# can store the default result where the exception frame was. + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.w &0x30d8,EXC_VOFF(%a6) # vector offset = 0xd0 + mov.w &0xe006,2+FP_SRC(%a6) # set fsave status + + frestore FP_SRC(%a6) # restore src operand + + mov.l (%a6),%a6 # restore frame pointer + + mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) + mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) + mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) + +# now, we copy the default result to its proper location + mov.l LOCAL_SIZE+FP_DST_EX(%sp),LOCAL_SIZE+0x4(%sp) + mov.l LOCAL_SIZE+FP_DST_HI(%sp),LOCAL_SIZE+0x8(%sp) + mov.l LOCAL_SIZE+FP_DST_LO(%sp),LOCAL_SIZE+0xc(%sp) + + add.l &LOCAL_SIZE-0x8,%sp + + + bra.l _real_snan + +fu_operr_p: + btst &0x5,EXC_SR(%a6) + bne.w fu_operr_p_s + + mov.l EXC_A7(%a6),%a0 + mov.l %a0,%usp + bra.w fu_operr + +fu_operr_p_s: + cmpi.b SPCOND_FLG(%a6),&mda7_flg + bne.w fu_operr + +# the instruction was "fmove.p fpn,-(a7)" from supervisor mode. +# the strategy is to move the exception frame "down" 12 bytes. then, we +# can store the default result where the exception frame was. + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.w &0x30d0,EXC_VOFF(%a6) # vector offset = 0xd0 + mov.w &0xe004,2+FP_SRC(%a6) # set fsave status + + frestore FP_SRC(%a6) # restore src operand + + mov.l (%a6),%a6 # restore frame pointer + + mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) + mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) + mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) + +# now, we copy the default result to its proper location + mov.l LOCAL_SIZE+FP_DST_EX(%sp),LOCAL_SIZE+0x4(%sp) + mov.l LOCAL_SIZE+FP_DST_HI(%sp),LOCAL_SIZE+0x8(%sp) + mov.l LOCAL_SIZE+FP_DST_LO(%sp),LOCAL_SIZE+0xc(%sp) + + add.l &LOCAL_SIZE-0x8,%sp + + + bra.l _real_operr + +fu_inex_p2: + btst &0x5,EXC_SR(%a6) + bne.w fu_inex_s_p2 + + mov.l EXC_A7(%a6),%a0 + mov.l %a0,%usp + bra.w fu_inex + +fu_inex_s_p2: + cmpi.b SPCOND_FLG(%a6),&mda7_flg + bne.w fu_inex + +# the instruction was "fmove.p fpn,-(a7)" from supervisor mode. +# the strategy is to move the exception frame "down" 12 bytes. then, we +# can store the default result where the exception frame was. + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.w &0x30c4,EXC_VOFF(%a6) # vector offset = 0xc4 + mov.w &0xe001,2+FP_SRC(%a6) # set fsave status + + frestore FP_SRC(%a6) # restore src operand + + mov.l (%a6),%a6 # restore frame pointer + + mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) + mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) + mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) + +# now, we copy the default result to its proper location + mov.l LOCAL_SIZE+FP_DST_EX(%sp),LOCAL_SIZE+0x4(%sp) + mov.l LOCAL_SIZE+FP_DST_HI(%sp),LOCAL_SIZE+0x8(%sp) + mov.l LOCAL_SIZE+FP_DST_LO(%sp),LOCAL_SIZE+0xc(%sp) + + add.l &LOCAL_SIZE-0x8,%sp + + + bra.l _real_inex + +######################################################################### + +# +# if we're stuffing a source operand back into an fsave frame then we +# have to make sure that for single or double source operands that the +# format stuffed is as weird as the hardware usually makes it. +# + global funimp_skew +funimp_skew: + bfextu EXC_EXTWORD(%a6){&3:&3},%d0 # extract src specifier + cmpi.b %d0,&0x1 # was src sgl? + beq.b funimp_skew_sgl # yes + cmpi.b %d0,&0x5 # was src dbl? + beq.b funimp_skew_dbl # yes + rts + +funimp_skew_sgl: + mov.w FP_SRC_EX(%a6),%d0 # fetch DENORM exponent + andi.w &0x7fff,%d0 # strip sign + beq.b funimp_skew_sgl_not + cmpi.w %d0,&0x3f80 + bgt.b funimp_skew_sgl_not + neg.w %d0 # make exponent negative + addi.w &0x3f81,%d0 # find amt to shift + mov.l FP_SRC_HI(%a6),%d1 # fetch DENORM hi(man) + lsr.l %d0,%d1 # shift it + bset &31,%d1 # set j-bit + mov.l %d1,FP_SRC_HI(%a6) # insert new hi(man) + andi.w &0x8000,FP_SRC_EX(%a6) # clear old exponent + ori.w &0x3f80,FP_SRC_EX(%a6) # insert new "skewed" exponent +funimp_skew_sgl_not: + rts + +funimp_skew_dbl: + mov.w FP_SRC_EX(%a6),%d0 # fetch DENORM exponent + andi.w &0x7fff,%d0 # strip sign + beq.b funimp_skew_dbl_not + cmpi.w %d0,&0x3c00 + bgt.b funimp_skew_dbl_not + + tst.b FP_SRC_EX(%a6) # make "internal format" + smi.b 0x2+FP_SRC(%a6) + mov.w %d0,FP_SRC_EX(%a6) # insert exponent with cleared sign + clr.l %d0 # clear g,r,s + lea FP_SRC(%a6),%a0 # pass ptr to src op + mov.w &0x3c01,%d1 # pass denorm threshold + bsr.l dnrm_lp # denorm it + mov.w &0x3c00,%d0 # new exponent + tst.b 0x2+FP_SRC(%a6) # is sign set? + beq.b fss_dbl_denorm_done # no + bset &15,%d0 # set sign +fss_dbl_denorm_done: + bset &0x7,FP_SRC_HI(%a6) # set j-bit + mov.w %d0,FP_SRC_EX(%a6) # insert new exponent +funimp_skew_dbl_not: + rts + +######################################################################### + global _mem_write2 +_mem_write2: + btst &0x5,EXC_SR(%a6) + beq.l _dmem_write + mov.l 0x0(%a0),FP_DST_EX(%a6) + mov.l 0x4(%a0),FP_DST_HI(%a6) + mov.l 0x8(%a0),FP_DST_LO(%a6) + clr.l %d1 + rts + +######################################################################### +# XDEF **************************************************************** # +# _fpsp_effadd(): 060FPSP entry point for FP "Unimplemented # +# effective address" exception. # +# # +# This handler should be the first code executed upon taking the # +# FP Unimplemented Effective Address exception in an operating # +# system. # +# # +# XREF **************************************************************** # +# _imem_read_long() - read instruction longword # +# fix_skewed_ops() - adjust src operand in fsave frame # +# set_tag_x() - determine optype of src/dst operands # +# store_fpreg() - store opclass 0 or 2 result to FP regfile # +# unnorm_fix() - change UNNORM operands to NORM or ZERO # +# load_fpn2() - load dst operand from FP regfile # +# tbl_unsupp - add of table of emulation routines for opclass 0,2 # +# decbin() - convert packed data to FP binary data # +# _real_fpu_disabled() - "callout" for "FPU disabled" exception # +# _real_access() - "callout" for access error exception # +# _mem_read() - read extended immediate operand from memory # +# _fpsp_done() - "callout" for exit; work all done # +# _real_trace() - "callout" for Trace enabled exception # +# fmovm_dynamic() - emulate dynamic fmovm instruction # +# fmovm_ctrl() - emulate fmovm control instruction # +# # +# INPUT *************************************************************** # +# - The system stack contains the "Unimplemented <ea>" stk frame # +# # +# OUTPUT ************************************************************** # +# If access error: # +# - The system stack is changed to an access error stack frame # +# If FPU disabled: # +# - The system stack is changed to an FPU disabled stack frame # +# If Trace exception enabled: # +# - The system stack is changed to a Trace exception stack frame # +# Else: (normal case) # +# - None (correct result has been stored as appropriate) # +# # +# ALGORITHM *********************************************************** # +# This exception handles 3 types of operations: # +# (1) FP Instructions using extended precision or packed immediate # +# addressing mode. # +# (2) The "fmovm.x" instruction w/ dynamic register specification. # +# (3) The "fmovm.l" instruction w/ 2 or 3 control registers. # +# # +# For immediate data operations, the data is read in w/ a # +# _mem_read() "callout", converted to FP binary (if packed), and used # +# as the source operand to the instruction specified by the instruction # +# word. If no FP exception should be reported ads a result of the # +# emulation, then the result is stored to the destination register and # +# the handler exits through _fpsp_done(). If an enabled exc has been # +# signalled as a result of emulation, then an fsave state frame # +# corresponding to the FP exception type must be entered into the 060 # +# FPU before exiting. In either the enabled or disabled cases, we # +# must also check if a Trace exception is pending, in which case, we # +# must create a Trace exception stack frame from the current exception # +# stack frame. If no Trace is pending, we simply exit through # +# _fpsp_done(). # +# For "fmovm.x", call the routine fmovm_dynamic() which will # +# decode and emulate the instruction. No FP exceptions can be pending # +# as a result of this operation emulation. A Trace exception can be # +# pending, though, which means the current stack frame must be changed # +# to a Trace stack frame and an exit made through _real_trace(). # +# For the case of "fmovm.x Dn,-(a7)", where the offending instruction # +# was executed from supervisor mode, this handler must store the FP # +# register file values to the system stack by itself since # +# fmovm_dynamic() can't handle this. A normal exit is made through # +# fpsp_done(). # +# For "fmovm.l", fmovm_ctrl() is used to emulate the instruction. # +# Again, a Trace exception may be pending and an exit made through # +# _real_trace(). Else, a normal exit is made through _fpsp_done(). # +# # +# Before any of the above is attempted, it must be checked to # +# see if the FPU is disabled. Since the "Unimp <ea>" exception is taken # +# before the "FPU disabled" exception, but the "FPU disabled" exception # +# has higher priority, we check the disabled bit in the PCR. If set, # +# then we must create an 8 word "FPU disabled" exception stack frame # +# from the current 4 word exception stack frame. This includes # +# reproducing the effective address of the instruction to put on the # +# new stack frame. # +# # +# In the process of all emulation work, if a _mem_read() # +# "callout" returns a failing result indicating an access error, then # +# we must create an access error stack frame from the current stack # +# frame. This information includes a faulting address and a fault- # +# status-longword. These are created within this handler. # +# # +######################################################################### + + global _fpsp_effadd +_fpsp_effadd: + +# This exception type takes priority over the "Line F Emulator" +# exception. Therefore, the FPU could be disabled when entering here. +# So, we must check to see if it's disabled and handle that case separately. + mov.l %d0,-(%sp) # save d0 + movc %pcr,%d0 # load proc cr + btst &0x1,%d0 # is FPU disabled? + bne.w iea_disabled # yes + mov.l (%sp)+,%d0 # restore d0 + + link %a6,&-LOCAL_SIZE # init stack frame + + movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 + fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs + fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack + +# PC of instruction that took the exception is the PC in the frame + mov.l EXC_PC(%a6),EXC_EXTWPTR(%a6) + + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch the instruction words + mov.l %d0,EXC_OPWORD(%a6) # store OPWORD and EXTWORD + +######################################################################### + + tst.w %d0 # is operation fmovem? + bmi.w iea_fmovm # yes + +# +# here, we will have: +# fabs fdabs fsabs facos fmod +# fadd fdadd fsadd fasin frem +# fcmp fatan fscale +# fdiv fddiv fsdiv fatanh fsin +# fint fcos fsincos +# fintrz fcosh fsinh +# fmove fdmove fsmove fetox ftan +# fmul fdmul fsmul fetoxm1 ftanh +# fneg fdneg fsneg fgetexp ftentox +# fsgldiv fgetman ftwotox +# fsglmul flog10 +# fsqrt flog2 +# fsub fdsub fssub flogn +# ftst flognp1 +# which can all use f<op>.{x,p} +# so, now it's immediate data extended precision AND PACKED FORMAT! +# +iea_op: + andi.l &0x00ff00ff,USER_FPSR(%a6) + + btst &0xa,%d0 # is src fmt x or p? + bne.b iea_op_pack # packed + + + mov.l EXC_EXTWPTR(%a6),%a0 # pass: ptr to #<data> + lea FP_SRC(%a6),%a1 # pass: ptr to super addr + mov.l &0xc,%d0 # pass: 12 bytes + bsr.l _imem_read # read extended immediate + + tst.l %d1 # did ifetch fail? + bne.w iea_iacc # yes + + bra.b iea_op_setsrc + +iea_op_pack: + + mov.l EXC_EXTWPTR(%a6),%a0 # pass: ptr to #<data> + lea FP_SRC(%a6),%a1 # pass: ptr to super dst + mov.l &0xc,%d0 # pass: 12 bytes + bsr.l _imem_read # read packed operand + + tst.l %d1 # did ifetch fail? + bne.w iea_iacc # yes + +# The packed operand is an INF or a NAN if the exponent field is all ones. + bfextu FP_SRC(%a6){&1:&15},%d0 # get exp + cmpi.w %d0,&0x7fff # INF or NAN? + beq.b iea_op_setsrc # operand is an INF or NAN + +# The packed operand is a zero if the mantissa is all zero, else it's +# a normal packed op. + mov.b 3+FP_SRC(%a6),%d0 # get byte 4 + andi.b &0x0f,%d0 # clear all but last nybble + bne.b iea_op_gp_not_spec # not a zero + tst.l FP_SRC_HI(%a6) # is lw 2 zero? + bne.b iea_op_gp_not_spec # not a zero + tst.l FP_SRC_LO(%a6) # is lw 3 zero? + beq.b iea_op_setsrc # operand is a ZERO +iea_op_gp_not_spec: + lea FP_SRC(%a6),%a0 # pass: ptr to packed op + bsr.l decbin # convert to extended + fmovm.x &0x80,FP_SRC(%a6) # make this the srcop + +iea_op_setsrc: + addi.l &0xc,EXC_EXTWPTR(%a6) # update extension word pointer + +# FP_SRC now holds the src operand. + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l set_tag_x # tag the operand type + mov.b %d0,STAG(%a6) # could be ANYTHING!!! + cmpi.b %d0,&UNNORM # is operand an UNNORM? + bne.b iea_op_getdst # no + bsr.l unnorm_fix # yes; convert to NORM/DENORM/ZERO + mov.b %d0,STAG(%a6) # set new optype tag +iea_op_getdst: + clr.b STORE_FLG(%a6) # clear "store result" boolean + + btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? + beq.b iea_op_extract # monadic + btst &0x4,1+EXC_CMDREG(%a6) # is operation fsincos,ftst,fcmp? + bne.b iea_op_spec # yes + +iea_op_loaddst: + bfextu EXC_CMDREG(%a6){&6:&3},%d0 # fetch dst regno + bsr.l load_fpn2 # load dst operand + + lea FP_DST(%a6),%a0 # pass: ptr to dst op + bsr.l set_tag_x # tag the operand type + mov.b %d0,DTAG(%a6) # could be ANYTHING!!! + cmpi.b %d0,&UNNORM # is operand an UNNORM? + bne.b iea_op_extract # no + bsr.l unnorm_fix # yes; convert to NORM/DENORM/ZERO + mov.b %d0,DTAG(%a6) # set new optype tag + bra.b iea_op_extract + +# the operation is fsincos, ftst, or fcmp. only fcmp is dyadic +iea_op_spec: + btst &0x3,1+EXC_CMDREG(%a6) # is operation fsincos? + beq.b iea_op_extract # yes +# now, we're left with ftst and fcmp. so, first let's tag them so that they don't +# store a result. then, only fcmp will branch back and pick up a dst operand. + st STORE_FLG(%a6) # don't store a final result + btst &0x1,1+EXC_CMDREG(%a6) # is operation fcmp? + beq.b iea_op_loaddst # yes + +iea_op_extract: + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # pass: rnd mode,prec + + mov.b 1+EXC_CMDREG(%a6),%d1 + andi.w &0x007f,%d1 # extract extension + + fmov.l &0x0,%fpcr + fmov.l &0x0,%fpsr + + lea FP_SRC(%a6),%a0 + lea FP_DST(%a6),%a1 + + mov.l (tbl_unsupp.l,%pc,%d1.w*4),%d1 # fetch routine addr + jsr (tbl_unsupp.l,%pc,%d1.l*1) + +# +# Exceptions in order of precedence: +# BSUN : none +# SNAN : all operations +# OPERR : all reg-reg or mem-reg operations that can normally operr +# OVFL : same as OPERR +# UNFL : same as OPERR +# DZ : same as OPERR +# INEX2 : same as OPERR +# INEX1 : all packed immediate operations +# + +# we determine the highest priority exception(if any) set by the +# emulation routine that has also been enabled by the user. + mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions enabled + bne.b iea_op_ena # some are enabled + +# now, we save the result, unless, of course, the operation was ftst or fcmp. +# these don't save results. +iea_op_save: + tst.b STORE_FLG(%a6) # does this op store a result? + bne.b iea_op_exit1 # exit with no frestore + +iea_op_store: + bfextu EXC_CMDREG(%a6){&6:&3},%d0 # fetch dst regno + bsr.l store_fpreg # store the result + +iea_op_exit1: + mov.l EXC_PC(%a6),USER_FPIAR(%a6) # set FPIAR to "Current PC" + mov.l EXC_EXTWPTR(%a6),EXC_PC(%a6) # set "Next PC" in exc frame + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 # unravel the frame + + btst &0x7,(%sp) # is trace on? + bne.w iea_op_trace # yes + + bra.l _fpsp_done # exit to os + +iea_op_ena: + and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enable and set + bfffo %d0{&24:&8},%d0 # find highest priority exception + bne.b iea_op_exc # at least one was set + +# no exception occurred. now, did a disabled, exact overflow occur with inexact +# enabled? if so, then we have to stuff an overflow frame into the FPU. + btst &ovfl_bit,FPSR_EXCEPT(%a6) # did overflow occur? + beq.b iea_op_save + +iea_op_ovfl: + btst &inex2_bit,FPCR_ENABLE(%a6) # is inexact enabled? + beq.b iea_op_store # no + bra.b iea_op_exc_ovfl # yes + +# an enabled exception occurred. we have to insert the exception type back into +# the machine. +iea_op_exc: + subi.l &24,%d0 # fix offset to be 0-8 + cmpi.b %d0,&0x6 # is exception INEX? + bne.b iea_op_exc_force # no + +# the enabled exception was inexact. so, if it occurs with an overflow +# or underflow that was disabled, then we have to force an overflow or +# underflow frame. + btst &ovfl_bit,FPSR_EXCEPT(%a6) # did overflow occur? + bne.b iea_op_exc_ovfl # yes + btst &unfl_bit,FPSR_EXCEPT(%a6) # did underflow occur? + bne.b iea_op_exc_unfl # yes + +iea_op_exc_force: + mov.w (tbl_iea_except.b,%pc,%d0.w*2),2+FP_SRC(%a6) + bra.b iea_op_exit2 # exit with frestore + +tbl_iea_except: + short 0xe002, 0xe006, 0xe004, 0xe005 + short 0xe003, 0xe002, 0xe001, 0xe001 + +iea_op_exc_ovfl: + mov.w &0xe005,2+FP_SRC(%a6) + bra.b iea_op_exit2 + +iea_op_exc_unfl: + mov.w &0xe003,2+FP_SRC(%a6) + +iea_op_exit2: + mov.l EXC_PC(%a6),USER_FPIAR(%a6) # set FPIAR to "Current PC" + mov.l EXC_EXTWPTR(%a6),EXC_PC(%a6) # set "Next PC" in exc frame + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) # restore exceptional state + + unlk %a6 # unravel the frame + + btst &0x7,(%sp) # is trace on? + bne.b iea_op_trace # yes + + bra.l _fpsp_done # exit to os + +# +# The opclass two instruction that took an "Unimplemented Effective Address" +# exception was being traced. Make the "current" PC the FPIAR and put it in +# the trace stack frame then jump to _real_trace(). +# +# UNIMP EA FRAME TRACE FRAME +# ***************** ***************** +# * 0x0 * 0x0f0 * * Current * +# ***************** * PC * +# * Current * ***************** +# * PC * * 0x2 * 0x024 * +# ***************** ***************** +# * SR * * Next * +# ***************** * PC * +# ***************** +# * SR * +# ***************** +iea_op_trace: + mov.l (%sp),-(%sp) # shift stack frame "down" + mov.w 0x8(%sp),0x4(%sp) + mov.w &0x2024,0x6(%sp) # stk fmt = 0x2; voff = 0x024 + fmov.l %fpiar,0x8(%sp) # "Current PC" is in FPIAR + + bra.l _real_trace + +######################################################################### +iea_fmovm: + btst &14,%d0 # ctrl or data reg + beq.w iea_fmovm_ctrl + +iea_fmovm_data: + + btst &0x5,EXC_SR(%a6) # user or supervisor mode + bne.b iea_fmovm_data_s + +iea_fmovm_data_u: + mov.l %usp,%a0 + mov.l %a0,EXC_A7(%a6) # store current a7 + bsr.l fmovm_dynamic # do dynamic fmovm + mov.l EXC_A7(%a6),%a0 # load possibly new a7 + mov.l %a0,%usp # update usp + bra.w iea_fmovm_exit + +iea_fmovm_data_s: + clr.b SPCOND_FLG(%a6) + lea 0x2+EXC_VOFF(%a6),%a0 + mov.l %a0,EXC_A7(%a6) + bsr.l fmovm_dynamic # do dynamic fmovm + + cmpi.b SPCOND_FLG(%a6),&mda7_flg + beq.w iea_fmovm_data_predec + cmpi.b SPCOND_FLG(%a6),&mia7_flg + bne.w iea_fmovm_exit + +# right now, d0 = the size. +# the data has been fetched from the supervisor stack, but we have not +# incremented the stack pointer by the appropriate number of bytes. +# do it here. +iea_fmovm_data_postinc: + btst &0x7,EXC_SR(%a6) + bne.b iea_fmovm_data_pi_trace + + mov.w EXC_SR(%a6),(EXC_SR,%a6,%d0) + mov.l EXC_EXTWPTR(%a6),(EXC_PC,%a6,%d0) + mov.w &0x00f0,(EXC_VOFF,%a6,%d0) + + lea (EXC_SR,%a6,%d0),%a0 + mov.l %a0,EXC_SR(%a6) + + fmovm.x EXC_FP0(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 + mov.l (%sp)+,%sp + bra.l _fpsp_done + +iea_fmovm_data_pi_trace: + mov.w EXC_SR(%a6),(EXC_SR-0x4,%a6,%d0) + mov.l EXC_EXTWPTR(%a6),(EXC_PC-0x4,%a6,%d0) + mov.w &0x2024,(EXC_VOFF-0x4,%a6,%d0) + mov.l EXC_PC(%a6),(EXC_VOFF+0x2-0x4,%a6,%d0) + + lea (EXC_SR-0x4,%a6,%d0),%a0 + mov.l %a0,EXC_SR(%a6) + + fmovm.x EXC_FP0(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 + mov.l (%sp)+,%sp + bra.l _real_trace + +# right now, d1 = size and d0 = the strg. +iea_fmovm_data_predec: + mov.b %d1,EXC_VOFF(%a6) # store strg + mov.b %d0,0x1+EXC_VOFF(%a6) # store size + + fmovm.x EXC_FP0(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + mov.l (%a6),-(%sp) # make a copy of a6 + mov.l %d0,-(%sp) # save d0 + mov.l %d1,-(%sp) # save d1 + mov.l EXC_EXTWPTR(%a6),-(%sp) # make a copy of Next PC + + clr.l %d0 + mov.b 0x1+EXC_VOFF(%a6),%d0 # fetch size + neg.l %d0 # get negative of size + + btst &0x7,EXC_SR(%a6) # is trace enabled? + beq.b iea_fmovm_data_p2 + + mov.w EXC_SR(%a6),(EXC_SR-0x4,%a6,%d0) + mov.l EXC_PC(%a6),(EXC_VOFF-0x2,%a6,%d0) + mov.l (%sp)+,(EXC_PC-0x4,%a6,%d0) + mov.w &0x2024,(EXC_VOFF-0x4,%a6,%d0) + + pea (%a6,%d0) # create final sp + bra.b iea_fmovm_data_p3 + +iea_fmovm_data_p2: + mov.w EXC_SR(%a6),(EXC_SR,%a6,%d0) + mov.l (%sp)+,(EXC_PC,%a6,%d0) + mov.w &0x00f0,(EXC_VOFF,%a6,%d0) + + pea (0x4,%a6,%d0) # create final sp + +iea_fmovm_data_p3: + clr.l %d1 + mov.b EXC_VOFF(%a6),%d1 # fetch strg + + tst.b %d1 + bpl.b fm_1 + fmovm.x &0x80,(0x4+0x8,%a6,%d0) + addi.l &0xc,%d0 +fm_1: + lsl.b &0x1,%d1 + bpl.b fm_2 + fmovm.x &0x40,(0x4+0x8,%a6,%d0) + addi.l &0xc,%d0 +fm_2: + lsl.b &0x1,%d1 + bpl.b fm_3 + fmovm.x &0x20,(0x4+0x8,%a6,%d0) + addi.l &0xc,%d0 +fm_3: + lsl.b &0x1,%d1 + bpl.b fm_4 + fmovm.x &0x10,(0x4+0x8,%a6,%d0) + addi.l &0xc,%d0 +fm_4: + lsl.b &0x1,%d1 + bpl.b fm_5 + fmovm.x &0x08,(0x4+0x8,%a6,%d0) + addi.l &0xc,%d0 +fm_5: + lsl.b &0x1,%d1 + bpl.b fm_6 + fmovm.x &0x04,(0x4+0x8,%a6,%d0) + addi.l &0xc,%d0 +fm_6: + lsl.b &0x1,%d1 + bpl.b fm_7 + fmovm.x &0x02,(0x4+0x8,%a6,%d0) + addi.l &0xc,%d0 +fm_7: + lsl.b &0x1,%d1 + bpl.b fm_end + fmovm.x &0x01,(0x4+0x8,%a6,%d0) +fm_end: + mov.l 0x4(%sp),%d1 + mov.l 0x8(%sp),%d0 + mov.l 0xc(%sp),%a6 + mov.l (%sp)+,%sp + + btst &0x7,(%sp) # is trace enabled? + beq.l _fpsp_done + bra.l _real_trace + +######################################################################### +iea_fmovm_ctrl: + + bsr.l fmovm_ctrl # load ctrl regs + +iea_fmovm_exit: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + btst &0x7,EXC_SR(%a6) # is trace on? + bne.b iea_fmovm_trace # yes + + mov.l EXC_EXTWPTR(%a6),EXC_PC(%a6) # set Next PC + + unlk %a6 # unravel the frame + + bra.l _fpsp_done # exit to os + +# +# The control reg instruction that took an "Unimplemented Effective Address" +# exception was being traced. The "Current PC" for the trace frame is the +# PC stacked for Unimp EA. The "Next PC" is in EXC_EXTWPTR. +# After fixing the stack frame, jump to _real_trace(). +# +# UNIMP EA FRAME TRACE FRAME +# ***************** ***************** +# * 0x0 * 0x0f0 * * Current * +# ***************** * PC * +# * Current * ***************** +# * PC * * 0x2 * 0x024 * +# ***************** ***************** +# * SR * * Next * +# ***************** * PC * +# ***************** +# * SR * +# ***************** +# this ain't a pretty solution, but it works: +# -restore a6 (not with unlk) +# -shift stack frame down over where old a6 used to be +# -add LOCAL_SIZE to stack pointer +iea_fmovm_trace: + mov.l (%a6),%a6 # restore frame pointer + mov.w EXC_SR+LOCAL_SIZE(%sp),0x0+LOCAL_SIZE(%sp) + mov.l EXC_PC+LOCAL_SIZE(%sp),0x8+LOCAL_SIZE(%sp) + mov.l EXC_EXTWPTR+LOCAL_SIZE(%sp),0x2+LOCAL_SIZE(%sp) + mov.w &0x2024,0x6+LOCAL_SIZE(%sp) # stk fmt = 0x2; voff = 0x024 + add.l &LOCAL_SIZE,%sp # clear stack frame + + bra.l _real_trace + +######################################################################### +# The FPU is disabled and so we should really have taken the "Line +# F Emulator" exception. So, here we create an 8-word stack frame +# from our 4-word stack frame. This means we must calculate the length +# the faulting instruction to get the "next PC". This is trivial for +# immediate operands but requires some extra work for fmovm dynamic +# which can use most addressing modes. +iea_disabled: + mov.l (%sp)+,%d0 # restore d0 + + link %a6,&-LOCAL_SIZE # init stack frame + + movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 + +# PC of instruction that took the exception is the PC in the frame + mov.l EXC_PC(%a6),EXC_EXTWPTR(%a6) + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch the instruction words + mov.l %d0,EXC_OPWORD(%a6) # store OPWORD and EXTWORD + + tst.w %d0 # is instr fmovm? + bmi.b iea_dis_fmovm # yes +# instruction is using an extended precision immediate operand. Therefore, +# the total instruction length is 16 bytes. +iea_dis_immed: + mov.l &0x10,%d0 # 16 bytes of instruction + bra.b iea_dis_cont +iea_dis_fmovm: + btst &0xe,%d0 # is instr fmovm ctrl + bne.b iea_dis_fmovm_data # no +# the instruction is a fmovm.l with 2 or 3 registers. + bfextu %d0{&19:&3},%d1 + mov.l &0xc,%d0 + cmpi.b %d1,&0x7 # move all regs? + bne.b iea_dis_cont + addq.l &0x4,%d0 + bra.b iea_dis_cont +# the instruction is an fmovm.x dynamic which can use many addressing +# modes and thus can have several different total instruction lengths. +# call fmovm_calc_ea which will go through the ea calc process and, +# as a by-product, will tell us how long the instruction is. +iea_dis_fmovm_data: + clr.l %d0 + bsr.l fmovm_calc_ea + mov.l EXC_EXTWPTR(%a6),%d0 + sub.l EXC_PC(%a6),%d0 +iea_dis_cont: + mov.w %d0,EXC_VOFF(%a6) # store stack shift value + + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 + +# here, we actually create the 8-word frame from the 4-word frame, +# with the "next PC" as additional info. +# the <ea> field is let as undefined. + subq.l &0x8,%sp # make room for new stack + mov.l %d0,-(%sp) # save d0 + mov.w 0xc(%sp),0x4(%sp) # move SR + mov.l 0xe(%sp),0x6(%sp) # move Current PC + clr.l %d0 + mov.w 0x12(%sp),%d0 + mov.l 0x6(%sp),0x10(%sp) # move Current PC + add.l %d0,0x6(%sp) # make Next PC + mov.w &0x402c,0xa(%sp) # insert offset,frame format + mov.l (%sp)+,%d0 # restore d0 + + bra.l _real_fpu_disabled + +########## + +iea_iacc: + movc %pcr,%d0 + btst &0x1,%d0 + bne.b iea_iacc_cont + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 on stack +iea_iacc_cont: + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 + + subq.w &0x8,%sp # make stack frame bigger + mov.l 0x8(%sp),(%sp) # store SR,hi(PC) + mov.w 0xc(%sp),0x4(%sp) # store lo(PC) + mov.w &0x4008,0x6(%sp) # store voff + mov.l 0x2(%sp),0x8(%sp) # store ea + mov.l &0x09428001,0xc(%sp) # store fslw + +iea_acc_done: + btst &0x5,(%sp) # user or supervisor mode? + beq.b iea_acc_done2 # user + bset &0x2,0xd(%sp) # set supervisor TM bit + +iea_acc_done2: + bra.l _real_access + +iea_dacc: + lea -LOCAL_SIZE(%a6),%sp + + movc %pcr,%d1 + btst &0x1,%d1 + bne.b iea_dacc_cont + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 on stack + fmovm.l LOCAL_SIZE+USER_FPCR(%sp),%fpcr,%fpsr,%fpiar # restore ctrl regs +iea_dacc_cont: + mov.l (%a6),%a6 + + mov.l 0x4+LOCAL_SIZE(%sp),-0x8+0x4+LOCAL_SIZE(%sp) + mov.w 0x8+LOCAL_SIZE(%sp),-0x8+0x8+LOCAL_SIZE(%sp) + mov.w &0x4008,-0x8+0xa+LOCAL_SIZE(%sp) + mov.l %a0,-0x8+0xc+LOCAL_SIZE(%sp) + mov.w %d0,-0x8+0x10+LOCAL_SIZE(%sp) + mov.w &0x0001,-0x8+0x12+LOCAL_SIZE(%sp) + + movm.l LOCAL_SIZE+EXC_DREGS(%sp),&0x0303 # restore d0-d1/a0-a1 + add.w &LOCAL_SIZE-0x4,%sp + + bra.b iea_acc_done + +######################################################################### +# XDEF **************************************************************** # +# _fpsp_operr(): 060FPSP entry point for FP Operr exception. # +# # +# This handler should be the first code executed upon taking the # +# FP Operand Error exception in an operating system. # +# # +# XREF **************************************************************** # +# _imem_read_long() - read instruction longword # +# fix_skewed_ops() - adjust src operand in fsave frame # +# _real_operr() - "callout" to operating system operr handler # +# _dmem_write_{byte,word,long}() - store data to mem (opclass 3) # +# store_dreg_{b,w,l}() - store data to data regfile (opclass 3) # +# facc_out_{b,w,l}() - store to memory took access error (opcl 3) # +# # +# INPUT *************************************************************** # +# - The system stack contains the FP Operr exception frame # +# - The fsave frame contains the source operand # +# # +# OUTPUT ************************************************************** # +# No access error: # +# - The system stack is unchanged # +# - The fsave frame contains the adjusted src op for opclass 0,2 # +# # +# ALGORITHM *********************************************************** # +# In a system where the FP Operr exception is enabled, the goal # +# is to get to the handler specified at _real_operr(). But, on the 060, # +# for opclass zero and two instruction taking this exception, the # +# input operand in the fsave frame may be incorrect for some cases # +# and needs to be corrected. This handler calls fix_skewed_ops() to # +# do just this and then exits through _real_operr(). # +# For opclass 3 instructions, the 060 doesn't store the default # +# operr result out to memory or data register file as it should. # +# This code must emulate the move out before finally exiting through # +# _real_inex(). The move out, if to memory, is performed using # +# _mem_write() "callout" routines that may return a failing result. # +# In this special case, the handler must exit through facc_out() # +# which creates an access error stack frame from the current operr # +# stack frame. # +# # +######################################################################### + + global _fpsp_operr +_fpsp_operr: + + link.w %a6,&-LOCAL_SIZE # init stack frame + + fsave FP_SRC(%a6) # grab the "busy" frame + + movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 + fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs + fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack + +# the FPIAR holds the "current PC" of the faulting instruction + mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) + + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch the instruction words + mov.l %d0,EXC_OPWORD(%a6) + +############################################################################## + + btst &13,%d0 # is instr an fmove out? + bne.b foperr_out # fmove out + + +# here, we simply see if the operand in the fsave frame needs to be "unskewed". +# this would be the case for opclass two operations with a source infinity or +# denorm operand in the sgl or dbl format. NANs also become skewed, but can't +# cause an operr so we don't need to check for them here. + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l fix_skewed_ops # fix src op + +foperr_exit: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) + + unlk %a6 + bra.l _real_operr + +######################################################################## + +# +# the hardware does not save the default result to memory on enabled +# operand error exceptions. we do this here before passing control to +# the user operand error handler. +# +# byte, word, and long destination format operations can pass +# through here. we simply need to test the sign of the src +# operand and save the appropriate minimum or maximum integer value +# to the effective address as pointed to by the stacked effective address. +# +# although packed opclass three operations can take operand error +# exceptions, they won't pass through here since they are caught +# first by the unsupported data format exception handler. that handler +# sends them directly to _real_operr() if necessary. +# +foperr_out: + + mov.w FP_SRC_EX(%a6),%d1 # fetch exponent + andi.w &0x7fff,%d1 + cmpi.w %d1,&0x7fff + bne.b foperr_out_not_qnan +# the operand is either an infinity or a QNAN. + tst.l FP_SRC_LO(%a6) + bne.b foperr_out_qnan + mov.l FP_SRC_HI(%a6),%d1 + andi.l &0x7fffffff,%d1 + beq.b foperr_out_not_qnan +foperr_out_qnan: + mov.l FP_SRC_HI(%a6),L_SCR1(%a6) + bra.b foperr_out_jmp + +foperr_out_not_qnan: + mov.l &0x7fffffff,%d1 + tst.b FP_SRC_EX(%a6) + bpl.b foperr_out_not_qnan2 + addq.l &0x1,%d1 +foperr_out_not_qnan2: + mov.l %d1,L_SCR1(%a6) + +foperr_out_jmp: + bfextu %d0{&19:&3},%d0 # extract dst format field + mov.b 1+EXC_OPWORD(%a6),%d1 # extract <ea> mode,reg + mov.w (tbl_operr.b,%pc,%d0.w*2),%a0 + jmp (tbl_operr.b,%pc,%a0) + +tbl_operr: + short foperr_out_l - tbl_operr # long word integer + short tbl_operr - tbl_operr # sgl prec shouldn't happen + short tbl_operr - tbl_operr # ext prec shouldn't happen + short foperr_exit - tbl_operr # packed won't enter here + short foperr_out_w - tbl_operr # word integer + short tbl_operr - tbl_operr # dbl prec shouldn't happen + short foperr_out_b - tbl_operr # byte integer + short tbl_operr - tbl_operr # packed won't enter here + +foperr_out_b: + mov.b L_SCR1(%a6),%d0 # load positive default result + cmpi.b %d1,&0x7 # is <ea> mode a data reg? + ble.b foperr_out_b_save_dn # yes + mov.l EXC_EA(%a6),%a0 # pass: <ea> of default result + bsr.l _dmem_write_byte # write the default result + + tst.l %d1 # did dstore fail? + bne.l facc_out_b # yes + + bra.w foperr_exit +foperr_out_b_save_dn: + andi.w &0x0007,%d1 + bsr.l store_dreg_b # store result to regfile + bra.w foperr_exit + +foperr_out_w: + mov.w L_SCR1(%a6),%d0 # load positive default result + cmpi.b %d1,&0x7 # is <ea> mode a data reg? + ble.b foperr_out_w_save_dn # yes + mov.l EXC_EA(%a6),%a0 # pass: <ea> of default result + bsr.l _dmem_write_word # write the default result + + tst.l %d1 # did dstore fail? + bne.l facc_out_w # yes + + bra.w foperr_exit +foperr_out_w_save_dn: + andi.w &0x0007,%d1 + bsr.l store_dreg_w # store result to regfile + bra.w foperr_exit + +foperr_out_l: + mov.l L_SCR1(%a6),%d0 # load positive default result + cmpi.b %d1,&0x7 # is <ea> mode a data reg? + ble.b foperr_out_l_save_dn # yes + mov.l EXC_EA(%a6),%a0 # pass: <ea> of default result + bsr.l _dmem_write_long # write the default result + + tst.l %d1 # did dstore fail? + bne.l facc_out_l # yes + + bra.w foperr_exit +foperr_out_l_save_dn: + andi.w &0x0007,%d1 + bsr.l store_dreg_l # store result to regfile + bra.w foperr_exit + +######################################################################### +# XDEF **************************************************************** # +# _fpsp_snan(): 060FPSP entry point for FP SNAN exception. # +# # +# This handler should be the first code executed upon taking the # +# FP Signalling NAN exception in an operating system. # +# # +# XREF **************************************************************** # +# _imem_read_long() - read instruction longword # +# fix_skewed_ops() - adjust src operand in fsave frame # +# _real_snan() - "callout" to operating system SNAN handler # +# _dmem_write_{byte,word,long}() - store data to mem (opclass 3) # +# store_dreg_{b,w,l}() - store data to data regfile (opclass 3) # +# facc_out_{b,w,l,d,x}() - store to mem took acc error (opcl 3) # +# _calc_ea_fout() - fix An if <ea> is -() or ()+; also get <ea> # +# # +# INPUT *************************************************************** # +# - The system stack contains the FP SNAN exception frame # +# - The fsave frame contains the source operand # +# # +# OUTPUT ************************************************************** # +# No access error: # +# - The system stack is unchanged # +# - The fsave frame contains the adjusted src op for opclass 0,2 # +# # +# ALGORITHM *********************************************************** # +# In a system where the FP SNAN exception is enabled, the goal # +# is to get to the handler specified at _real_snan(). But, on the 060, # +# for opclass zero and two instructions taking this exception, the # +# input operand in the fsave frame may be incorrect for some cases # +# and needs to be corrected. This handler calls fix_skewed_ops() to # +# do just this and then exits through _real_snan(). # +# For opclass 3 instructions, the 060 doesn't store the default # +# SNAN result out to memory or data register file as it should. # +# This code must emulate the move out before finally exiting through # +# _real_snan(). The move out, if to memory, is performed using # +# _mem_write() "callout" routines that may return a failing result. # +# In this special case, the handler must exit through facc_out() # +# which creates an access error stack frame from the current SNAN # +# stack frame. # +# For the case of an extended precision opclass 3 instruction, # +# if the effective addressing mode was -() or ()+, then the address # +# register must get updated by calling _calc_ea_fout(). If the <ea> # +# was -(a7) from supervisor mode, then the exception frame currently # +# on the system stack must be carefully moved "down" to make room # +# for the operand being moved. # +# # +######################################################################### + + global _fpsp_snan +_fpsp_snan: + + link.w %a6,&-LOCAL_SIZE # init stack frame + + fsave FP_SRC(%a6) # grab the "busy" frame + + movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 + fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs + fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack + +# the FPIAR holds the "current PC" of the faulting instruction + mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) + + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch the instruction words + mov.l %d0,EXC_OPWORD(%a6) + +############################################################################## + + btst &13,%d0 # is instr an fmove out? + bne.w fsnan_out # fmove out + + +# here, we simply see if the operand in the fsave frame needs to be "unskewed". +# this would be the case for opclass two operations with a source infinity or +# denorm operand in the sgl or dbl format. NANs also become skewed and must be +# fixed here. + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l fix_skewed_ops # fix src op + +fsnan_exit: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) + + unlk %a6 + bra.l _real_snan + +######################################################################## + +# +# the hardware does not save the default result to memory on enabled +# snan exceptions. we do this here before passing control to +# the user snan handler. +# +# byte, word, long, and packed destination format operations can pass +# through here. since packed format operations already were handled by +# fpsp_unsupp(), then we need to do nothing else for them here. +# for byte, word, and long, we simply need to test the sign of the src +# operand and save the appropriate minimum or maximum integer value +# to the effective address as pointed to by the stacked effective address. +# +fsnan_out: + + bfextu %d0{&19:&3},%d0 # extract dst format field + mov.b 1+EXC_OPWORD(%a6),%d1 # extract <ea> mode,reg + mov.w (tbl_snan.b,%pc,%d0.w*2),%a0 + jmp (tbl_snan.b,%pc,%a0) + +tbl_snan: + short fsnan_out_l - tbl_snan # long word integer + short fsnan_out_s - tbl_snan # sgl prec shouldn't happen + short fsnan_out_x - tbl_snan # ext prec shouldn't happen + short tbl_snan - tbl_snan # packed needs no help + short fsnan_out_w - tbl_snan # word integer + short fsnan_out_d - tbl_snan # dbl prec shouldn't happen + short fsnan_out_b - tbl_snan # byte integer + short tbl_snan - tbl_snan # packed needs no help + +fsnan_out_b: + mov.b FP_SRC_HI(%a6),%d0 # load upper byte of SNAN + bset &6,%d0 # set SNAN bit + cmpi.b %d1,&0x7 # is <ea> mode a data reg? + ble.b fsnan_out_b_dn # yes + mov.l EXC_EA(%a6),%a0 # pass: <ea> of default result + bsr.l _dmem_write_byte # write the default result + + tst.l %d1 # did dstore fail? + bne.l facc_out_b # yes + + bra.w fsnan_exit +fsnan_out_b_dn: + andi.w &0x0007,%d1 + bsr.l store_dreg_b # store result to regfile + bra.w fsnan_exit + +fsnan_out_w: + mov.w FP_SRC_HI(%a6),%d0 # load upper word of SNAN + bset &14,%d0 # set SNAN bit + cmpi.b %d1,&0x7 # is <ea> mode a data reg? + ble.b fsnan_out_w_dn # yes + mov.l EXC_EA(%a6),%a0 # pass: <ea> of default result + bsr.l _dmem_write_word # write the default result + + tst.l %d1 # did dstore fail? + bne.l facc_out_w # yes + + bra.w fsnan_exit +fsnan_out_w_dn: + andi.w &0x0007,%d1 + bsr.l store_dreg_w # store result to regfile + bra.w fsnan_exit + +fsnan_out_l: + mov.l FP_SRC_HI(%a6),%d0 # load upper longword of SNAN + bset &30,%d0 # set SNAN bit + cmpi.b %d1,&0x7 # is <ea> mode a data reg? + ble.b fsnan_out_l_dn # yes + mov.l EXC_EA(%a6),%a0 # pass: <ea> of default result + bsr.l _dmem_write_long # write the default result + + tst.l %d1 # did dstore fail? + bne.l facc_out_l # yes + + bra.w fsnan_exit +fsnan_out_l_dn: + andi.w &0x0007,%d1 + bsr.l store_dreg_l # store result to regfile + bra.w fsnan_exit + +fsnan_out_s: + cmpi.b %d1,&0x7 # is <ea> mode a data reg? + ble.b fsnan_out_d_dn # yes + mov.l FP_SRC_EX(%a6),%d0 # fetch SNAN sign + andi.l &0x80000000,%d0 # keep sign + ori.l &0x7fc00000,%d0 # insert new exponent,SNAN bit + mov.l FP_SRC_HI(%a6),%d1 # load mantissa + lsr.l &0x8,%d1 # shift mantissa for sgl + or.l %d1,%d0 # create sgl SNAN + mov.l EXC_EA(%a6),%a0 # pass: <ea> of default result + bsr.l _dmem_write_long # write the default result + + tst.l %d1 # did dstore fail? + bne.l facc_out_l # yes + + bra.w fsnan_exit +fsnan_out_d_dn: + mov.l FP_SRC_EX(%a6),%d0 # fetch SNAN sign + andi.l &0x80000000,%d0 # keep sign + ori.l &0x7fc00000,%d0 # insert new exponent,SNAN bit + mov.l %d1,-(%sp) + mov.l FP_SRC_HI(%a6),%d1 # load mantissa + lsr.l &0x8,%d1 # shift mantissa for sgl + or.l %d1,%d0 # create sgl SNAN + mov.l (%sp)+,%d1 + andi.w &0x0007,%d1 + bsr.l store_dreg_l # store result to regfile + bra.w fsnan_exit + +fsnan_out_d: + mov.l FP_SRC_EX(%a6),%d0 # fetch SNAN sign + andi.l &0x80000000,%d0 # keep sign + ori.l &0x7ff80000,%d0 # insert new exponent,SNAN bit + mov.l FP_SRC_HI(%a6),%d1 # load hi mantissa + mov.l %d0,FP_SCR0_EX(%a6) # store to temp space + mov.l &11,%d0 # load shift amt + lsr.l %d0,%d1 + or.l %d1,FP_SCR0_EX(%a6) # create dbl hi + mov.l FP_SRC_HI(%a6),%d1 # load hi mantissa + andi.l &0x000007ff,%d1 + ror.l %d0,%d1 + mov.l %d1,FP_SCR0_HI(%a6) # store to temp space + mov.l FP_SRC_LO(%a6),%d1 # load lo mantissa + lsr.l %d0,%d1 + or.l %d1,FP_SCR0_HI(%a6) # create dbl lo + lea FP_SCR0(%a6),%a0 # pass: ptr to operand + mov.l EXC_EA(%a6),%a1 # pass: dst addr + movq.l &0x8,%d0 # pass: size of 8 bytes + bsr.l _dmem_write # write the default result + + tst.l %d1 # did dstore fail? + bne.l facc_out_d # yes + + bra.w fsnan_exit + +# for extended precision, if the addressing mode is pre-decrement or +# post-increment, then the address register did not get updated. +# in addition, for pre-decrement, the stacked <ea> is incorrect. +fsnan_out_x: + clr.b SPCOND_FLG(%a6) # clear special case flag + + mov.w FP_SRC_EX(%a6),FP_SCR0_EX(%a6) + clr.w 2+FP_SCR0(%a6) + mov.l FP_SRC_HI(%a6),%d0 + bset &30,%d0 + mov.l %d0,FP_SCR0_HI(%a6) + mov.l FP_SRC_LO(%a6),FP_SCR0_LO(%a6) + + btst &0x5,EXC_SR(%a6) # supervisor mode exception? + bne.b fsnan_out_x_s # yes + + mov.l %usp,%a0 # fetch user stack pointer + mov.l %a0,EXC_A7(%a6) # save on stack for calc_ea() + mov.l (%a6),EXC_A6(%a6) + + bsr.l _calc_ea_fout # find the correct ea,update An + mov.l %a0,%a1 + mov.l %a0,EXC_EA(%a6) # stack correct <ea> + + mov.l EXC_A7(%a6),%a0 + mov.l %a0,%usp # restore user stack pointer + mov.l EXC_A6(%a6),(%a6) + +fsnan_out_x_save: + lea FP_SCR0(%a6),%a0 # pass: ptr to operand + movq.l &0xc,%d0 # pass: size of extended + bsr.l _dmem_write # write the default result + + tst.l %d1 # did dstore fail? + bne.l facc_out_x # yes + + bra.w fsnan_exit + +fsnan_out_x_s: + mov.l (%a6),EXC_A6(%a6) + + bsr.l _calc_ea_fout # find the correct ea,update An + mov.l %a0,%a1 + mov.l %a0,EXC_EA(%a6) # stack correct <ea> + + mov.l EXC_A6(%a6),(%a6) + + cmpi.b SPCOND_FLG(%a6),&mda7_flg # is <ea> mode -(a7)? + bne.b fsnan_out_x_save # no + +# the operation was "fmove.x SNAN,-(a7)" from supervisor mode. + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) + + mov.l EXC_A6(%a6),%a6 # restore frame pointer + + mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) + mov.l LOCAL_SIZE+EXC_PC+0x2(%sp),LOCAL_SIZE+EXC_PC+0x2-0xc(%sp) + mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) + + mov.l LOCAL_SIZE+FP_SCR0_EX(%sp),LOCAL_SIZE+EXC_SR(%sp) + mov.l LOCAL_SIZE+FP_SCR0_HI(%sp),LOCAL_SIZE+EXC_PC+0x2(%sp) + mov.l LOCAL_SIZE+FP_SCR0_LO(%sp),LOCAL_SIZE+EXC_EA(%sp) + + add.l &LOCAL_SIZE-0x8,%sp + + bra.l _real_snan + +######################################################################### +# XDEF **************************************************************** # +# _fpsp_inex(): 060FPSP entry point for FP Inexact exception. # +# # +# This handler should be the first code executed upon taking the # +# FP Inexact exception in an operating system. # +# # +# XREF **************************************************************** # +# _imem_read_long() - read instruction longword # +# fix_skewed_ops() - adjust src operand in fsave frame # +# set_tag_x() - determine optype of src/dst operands # +# store_fpreg() - store opclass 0 or 2 result to FP regfile # +# unnorm_fix() - change UNNORM operands to NORM or ZERO # +# load_fpn2() - load dst operand from FP regfile # +# smovcr() - emulate an "fmovcr" instruction # +# fout() - emulate an opclass 3 instruction # +# tbl_unsupp - add of table of emulation routines for opclass 0,2 # +# _real_inex() - "callout" to operating system inexact handler # +# # +# INPUT *************************************************************** # +# - The system stack contains the FP Inexact exception frame # +# - The fsave frame contains the source operand # +# # +# OUTPUT ************************************************************** # +# - The system stack is unchanged # +# - The fsave frame contains the adjusted src op for opclass 0,2 # +# # +# ALGORITHM *********************************************************** # +# In a system where the FP Inexact exception is enabled, the goal # +# is to get to the handler specified at _real_inex(). But, on the 060, # +# for opclass zero and two instruction taking this exception, the # +# hardware doesn't store the correct result to the destination FP # +# register as did the '040 and '881/2. This handler must emulate the # +# instruction in order to get this value and then store it to the # +# correct register before calling _real_inex(). # +# For opclass 3 instructions, the 060 doesn't store the default # +# inexact result out to memory or data register file as it should. # +# This code must emulate the move out by calling fout() before finally # +# exiting through _real_inex(). # +# # +######################################################################### + + global _fpsp_inex +_fpsp_inex: + + link.w %a6,&-LOCAL_SIZE # init stack frame + + fsave FP_SRC(%a6) # grab the "busy" frame + + movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 + fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs + fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack + +# the FPIAR holds the "current PC" of the faulting instruction + mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) + + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch the instruction words + mov.l %d0,EXC_OPWORD(%a6) + +############################################################################## + + btst &13,%d0 # is instr an fmove out? + bne.w finex_out # fmove out + + +# the hardware, for "fabs" and "fneg" w/ a long source format, puts the +# longword integer directly into the upper longword of the mantissa along +# w/ an exponent value of 0x401e. we convert this to extended precision here. + bfextu %d0{&19:&3},%d0 # fetch instr size + bne.b finex_cont # instr size is not long + cmpi.w FP_SRC_EX(%a6),&0x401e # is exponent 0x401e? + bne.b finex_cont # no + fmov.l &0x0,%fpcr + fmov.l FP_SRC_HI(%a6),%fp0 # load integer src + fmov.x %fp0,FP_SRC(%a6) # store integer as extended precision + mov.w &0xe001,0x2+FP_SRC(%a6) + +finex_cont: + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l fix_skewed_ops # fix src op + +# Here, we zero the ccode and exception byte field since we're going to +# emulate the whole instruction. Notice, though, that we don't kill the +# INEX1 bit. This is because a packed op has long since been converted +# to extended before arriving here. Therefore, we need to retain the +# INEX1 bit from when the operand was first converted. + andi.l &0x00ff01ff,USER_FPSR(%a6) # zero all but accured field + + fmov.l &0x0,%fpcr # zero current control regs + fmov.l &0x0,%fpsr + + bfextu EXC_EXTWORD(%a6){&0:&6},%d1 # extract upper 6 of cmdreg + cmpi.b %d1,&0x17 # is op an fmovecr? + beq.w finex_fmovcr # yes + + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l set_tag_x # tag the operand type + mov.b %d0,STAG(%a6) # maybe NORM,DENORM + +# bits four and five of the fp extension word separate the monadic and dyadic +# operations that can pass through fpsp_inex(). remember that fcmp and ftst +# will never take this exception, but fsincos will. + btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? + beq.b finex_extract # monadic + + btst &0x4,1+EXC_CMDREG(%a6) # is operation an fsincos? + bne.b finex_extract # yes + + bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg + bsr.l load_fpn2 # load dst into FP_DST + + lea FP_DST(%a6),%a0 # pass: ptr to dst op + bsr.l set_tag_x # tag the operand type + cmpi.b %d0,&UNNORM # is operand an UNNORM? + bne.b finex_op2_done # no + bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO +finex_op2_done: + mov.b %d0,DTAG(%a6) # save dst optype tag + +finex_extract: + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode + + mov.b 1+EXC_CMDREG(%a6),%d1 + andi.w &0x007f,%d1 # extract extension + + lea FP_SRC(%a6),%a0 + lea FP_DST(%a6),%a1 + + mov.l (tbl_unsupp.l,%pc,%d1.w*4),%d1 # fetch routine addr + jsr (tbl_unsupp.l,%pc,%d1.l*1) + +# the operation has been emulated. the result is in fp0. +finex_save: + bfextu EXC_CMDREG(%a6){&6:&3},%d0 + bsr.l store_fpreg + +finex_exit: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) + + unlk %a6 + bra.l _real_inex + +finex_fmovcr: + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # pass rnd prec,mode + mov.b 1+EXC_CMDREG(%a6),%d1 + andi.l &0x0000007f,%d1 # pass rom offset + bsr.l smovcr + bra.b finex_save + +######################################################################## + +# +# the hardware does not save the default result to memory on enabled +# inexact exceptions. we do this here before passing control to +# the user inexact handler. +# +# byte, word, and long destination format operations can pass +# through here. so can double and single precision. +# although packed opclass three operations can take inexact +# exceptions, they won't pass through here since they are caught +# first by the unsupported data format exception handler. that handler +# sends them directly to _real_inex() if necessary. +# +finex_out: + + mov.b &NORM,STAG(%a6) # src is a NORM + + clr.l %d0 + mov.b FPCR_MODE(%a6),%d0 # pass rnd prec,mode + + andi.l &0xffff00ff,USER_FPSR(%a6) # zero exception field + + lea FP_SRC(%a6),%a0 # pass ptr to src operand + + bsr.l fout # store the default result + + bra.b finex_exit + +######################################################################### +# XDEF **************************************************************** # +# _fpsp_dz(): 060FPSP entry point for FP DZ exception. # +# # +# This handler should be the first code executed upon taking # +# the FP DZ exception in an operating system. # +# # +# XREF **************************************************************** # +# _imem_read_long() - read instruction longword from memory # +# fix_skewed_ops() - adjust fsave operand # +# _real_dz() - "callout" exit point from FP DZ handler # +# # +# INPUT *************************************************************** # +# - The system stack contains the FP DZ exception stack. # +# - The fsave frame contains the source operand. # +# # +# OUTPUT ************************************************************** # +# - The system stack contains the FP DZ exception stack. # +# - The fsave frame contains the adjusted source operand. # +# # +# ALGORITHM *********************************************************** # +# In a system where the DZ exception is enabled, the goal is to # +# get to the handler specified at _real_dz(). But, on the 060, when the # +# exception is taken, the input operand in the fsave state frame may # +# be incorrect for some cases and need to be adjusted. So, this package # +# adjusts the operand using fix_skewed_ops() and then branches to # +# _real_dz(). # +# # +######################################################################### + + global _fpsp_dz +_fpsp_dz: + + link.w %a6,&-LOCAL_SIZE # init stack frame + + fsave FP_SRC(%a6) # grab the "busy" frame + + movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 + fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs + fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack + +# the FPIAR holds the "current PC" of the faulting instruction + mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) + + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch the instruction words + mov.l %d0,EXC_OPWORD(%a6) + +############################################################################## + + +# here, we simply see if the operand in the fsave frame needs to be "unskewed". +# this would be the case for opclass two operations with a source zero +# in the sgl or dbl format. + lea FP_SRC(%a6),%a0 # pass: ptr to src op + bsr.l fix_skewed_ops # fix src op + +fdz_exit: + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + frestore FP_SRC(%a6) + + unlk %a6 + bra.l _real_dz + +######################################################################### +# XDEF **************************************************************** # +# _fpsp_fline(): 060FPSP entry point for "Line F emulator" # +# exception when the "reduced" version of the # +# FPSP is implemented that does not emulate # +# FP unimplemented instructions. # +# # +# This handler should be the first code executed upon taking a # +# "Line F Emulator" exception in an operating system integrating # +# the reduced version of 060FPSP. # +# # +# XREF **************************************************************** # +# _real_fpu_disabled() - Handle "FPU disabled" exceptions # +# _real_fline() - Handle all other cases (treated equally) # +# # +# INPUT *************************************************************** # +# - The system stack contains a "Line F Emulator" exception # +# stack frame. # +# # +# OUTPUT ************************************************************** # +# - The system stack is unchanged. # +# # +# ALGORITHM *********************************************************** # +# When a "Line F Emulator" exception occurs in a system where # +# "FPU Unimplemented" instructions will not be emulated, the exception # +# can occur because then FPU is disabled or the instruction is to be # +# classifed as "Line F". This module determines which case exists and # +# calls the appropriate "callout". # +# # +######################################################################### + + global _fpsp_fline +_fpsp_fline: + +# check to see if the FPU is disabled. if so, jump to the OS entry +# point for that condition. + cmpi.w 0x6(%sp),&0x402c + beq.l _real_fpu_disabled + + bra.l _real_fline + +######################################################################### +# XDEF **************************************************************** # +# _dcalc_ea(): calc correct <ea> from <ea> stacked on exception # +# # +# XREF **************************************************************** # +# inc_areg() - increment an address register # +# dec_areg() - decrement an address register # +# # +# INPUT *************************************************************** # +# d0 = number of bytes to adjust <ea> by # +# # +# OUTPUT ************************************************************** # +# None # +# # +# ALGORITHM *********************************************************** # +# "Dummy" CALCulate Effective Address: # +# The stacked <ea> for FP unimplemented instructions and opclass # +# two packed instructions is correct with the exception of... # +# # +# 1) -(An) : The register is not updated regardless of size. # +# Also, for extended precision and packed, the # +# stacked <ea> value is 8 bytes too big # +# 2) (An)+ : The register is not updated. # +# 3) #<data> : The upper longword of the immediate operand is # +# stacked b,w,l and s sizes are completely stacked. # +# d,x, and p are not. # +# # +######################################################################### + + global _dcalc_ea +_dcalc_ea: + mov.l %d0, %a0 # move # bytes to %a0 + + mov.b 1+EXC_OPWORD(%a6), %d0 # fetch opcode word + mov.l %d0, %d1 # make a copy + + andi.w &0x38, %d0 # extract mode field + andi.l &0x7, %d1 # extract reg field + + cmpi.b %d0,&0x18 # is mode (An)+ ? + beq.b dcea_pi # yes + + cmpi.b %d0,&0x20 # is mode -(An) ? + beq.b dcea_pd # yes + + or.w %d1,%d0 # concat mode,reg + cmpi.b %d0,&0x3c # is mode #<data>? + + beq.b dcea_imm # yes + + mov.l EXC_EA(%a6),%a0 # return <ea> + rts + +# need to set immediate data flag here since we'll need to do +# an imem_read to fetch this later. +dcea_imm: + mov.b &immed_flg,SPCOND_FLG(%a6) + lea ([USER_FPIAR,%a6],0x4),%a0 # no; return <ea> + rts + +# here, the <ea> is stacked correctly. however, we must update the +# address register... +dcea_pi: + mov.l %a0,%d0 # pass amt to inc by + bsr.l inc_areg # inc addr register + + mov.l EXC_EA(%a6),%a0 # stacked <ea> is correct + rts + +# the <ea> is stacked correctly for all but extended and packed which +# the <ea>s are 8 bytes too large. +# it would make no sense to have a pre-decrement to a7 in supervisor +# mode so we don't even worry about this tricky case here : ) +dcea_pd: + mov.l %a0,%d0 # pass amt to dec by + bsr.l dec_areg # dec addr register + + mov.l EXC_EA(%a6),%a0 # stacked <ea> is correct + + cmpi.b %d0,&0xc # is opsize ext or packed? + beq.b dcea_pd2 # yes + rts +dcea_pd2: + sub.l &0x8,%a0 # correct <ea> + mov.l %a0,EXC_EA(%a6) # put correct <ea> on stack + rts + +######################################################################### +# XDEF **************************************************************** # +# _calc_ea_fout(): calculate correct stacked <ea> for extended # +# and packed data opclass 3 operations. # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# None # +# # +# OUTPUT ************************************************************** # +# a0 = return correct effective address # +# # +# ALGORITHM *********************************************************** # +# For opclass 3 extended and packed data operations, the <ea> # +# stacked for the exception is incorrect for -(an) and (an)+ addressing # +# modes. Also, while we're at it, the index register itself must get # +# updated. # +# So, for -(an), we must subtract 8 off of the stacked <ea> value # +# and return that value as the correct <ea> and store that value in An. # +# For (an)+, the stacked <ea> is correct but we must adjust An by +12. # +# # +######################################################################### + +# This calc_ea is currently used to retrieve the correct <ea> +# for fmove outs of type extended and packed. + global _calc_ea_fout +_calc_ea_fout: + mov.b 1+EXC_OPWORD(%a6),%d0 # fetch opcode word + mov.l %d0,%d1 # make a copy + + andi.w &0x38,%d0 # extract mode field + andi.l &0x7,%d1 # extract reg field + + cmpi.b %d0,&0x18 # is mode (An)+ ? + beq.b ceaf_pi # yes + + cmpi.b %d0,&0x20 # is mode -(An) ? + beq.w ceaf_pd # yes + + mov.l EXC_EA(%a6),%a0 # stacked <ea> is correct + rts + +# (An)+ : extended and packed fmove out +# : stacked <ea> is correct +# : "An" not updated +ceaf_pi: + mov.w (tbl_ceaf_pi.b,%pc,%d1.w*2),%d1 + mov.l EXC_EA(%a6),%a0 + jmp (tbl_ceaf_pi.b,%pc,%d1.w*1) + + swbeg &0x8 +tbl_ceaf_pi: + short ceaf_pi0 - tbl_ceaf_pi + short ceaf_pi1 - tbl_ceaf_pi + short ceaf_pi2 - tbl_ceaf_pi + short ceaf_pi3 - tbl_ceaf_pi + short ceaf_pi4 - tbl_ceaf_pi + short ceaf_pi5 - tbl_ceaf_pi + short ceaf_pi6 - tbl_ceaf_pi + short ceaf_pi7 - tbl_ceaf_pi + +ceaf_pi0: + addi.l &0xc,EXC_DREGS+0x8(%a6) + rts +ceaf_pi1: + addi.l &0xc,EXC_DREGS+0xc(%a6) + rts +ceaf_pi2: + add.l &0xc,%a2 + rts +ceaf_pi3: + add.l &0xc,%a3 + rts +ceaf_pi4: + add.l &0xc,%a4 + rts +ceaf_pi5: + add.l &0xc,%a5 + rts +ceaf_pi6: + addi.l &0xc,EXC_A6(%a6) + rts +ceaf_pi7: + mov.b &mia7_flg,SPCOND_FLG(%a6) + addi.l &0xc,EXC_A7(%a6) + rts + +# -(An) : extended and packed fmove out +# : stacked <ea> = actual <ea> + 8 +# : "An" not updated +ceaf_pd: + mov.w (tbl_ceaf_pd.b,%pc,%d1.w*2),%d1 + mov.l EXC_EA(%a6),%a0 + sub.l &0x8,%a0 + sub.l &0x8,EXC_EA(%a6) + jmp (tbl_ceaf_pd.b,%pc,%d1.w*1) + + swbeg &0x8 +tbl_ceaf_pd: + short ceaf_pd0 - tbl_ceaf_pd + short ceaf_pd1 - tbl_ceaf_pd + short ceaf_pd2 - tbl_ceaf_pd + short ceaf_pd3 - tbl_ceaf_pd + short ceaf_pd4 - tbl_ceaf_pd + short ceaf_pd5 - tbl_ceaf_pd + short ceaf_pd6 - tbl_ceaf_pd + short ceaf_pd7 - tbl_ceaf_pd + +ceaf_pd0: + mov.l %a0,EXC_DREGS+0x8(%a6) + rts +ceaf_pd1: + mov.l %a0,EXC_DREGS+0xc(%a6) + rts +ceaf_pd2: + mov.l %a0,%a2 + rts +ceaf_pd3: + mov.l %a0,%a3 + rts +ceaf_pd4: + mov.l %a0,%a4 + rts +ceaf_pd5: + mov.l %a0,%a5 + rts +ceaf_pd6: + mov.l %a0,EXC_A6(%a6) + rts +ceaf_pd7: + mov.l %a0,EXC_A7(%a6) + mov.b &mda7_flg,SPCOND_FLG(%a6) + rts + +# +# This table holds the offsets of the emulation routines for each individual +# math operation relative to the address of this table. Included are +# routines like fadd/fmul/fabs. The transcendentals ARE NOT. This is because +# this table is for the version if the 060FPSP without transcendentals. +# The location within the table is determined by the extension bits of the +# operation longword. +# + + swbeg &109 +tbl_unsupp: + long fin - tbl_unsupp # 00: fmove + long fint - tbl_unsupp # 01: fint + long tbl_unsupp - tbl_unsupp # 02: fsinh + long fintrz - tbl_unsupp # 03: fintrz + long fsqrt - tbl_unsupp # 04: fsqrt + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp # 06: flognp1 + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp # 08: fetoxm1 + long tbl_unsupp - tbl_unsupp # 09: ftanh + long tbl_unsupp - tbl_unsupp # 0a: fatan + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp # 0c: fasin + long tbl_unsupp - tbl_unsupp # 0d: fatanh + long tbl_unsupp - tbl_unsupp # 0e: fsin + long tbl_unsupp - tbl_unsupp # 0f: ftan + long tbl_unsupp - tbl_unsupp # 10: fetox + long tbl_unsupp - tbl_unsupp # 11: ftwotox + long tbl_unsupp - tbl_unsupp # 12: ftentox + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp # 14: flogn + long tbl_unsupp - tbl_unsupp # 15: flog10 + long tbl_unsupp - tbl_unsupp # 16: flog2 + long tbl_unsupp - tbl_unsupp + long fabs - tbl_unsupp # 18: fabs + long tbl_unsupp - tbl_unsupp # 19: fcosh + long fneg - tbl_unsupp # 1a: fneg + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp # 1c: facos + long tbl_unsupp - tbl_unsupp # 1d: fcos + long tbl_unsupp - tbl_unsupp # 1e: fgetexp + long tbl_unsupp - tbl_unsupp # 1f: fgetman + long fdiv - tbl_unsupp # 20: fdiv + long tbl_unsupp - tbl_unsupp # 21: fmod + long fadd - tbl_unsupp # 22: fadd + long fmul - tbl_unsupp # 23: fmul + long fsgldiv - tbl_unsupp # 24: fsgldiv + long tbl_unsupp - tbl_unsupp # 25: frem + long tbl_unsupp - tbl_unsupp # 26: fscale + long fsglmul - tbl_unsupp # 27: fsglmul + long fsub - tbl_unsupp # 28: fsub + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp # 30: fsincos + long tbl_unsupp - tbl_unsupp # 31: fsincos + long tbl_unsupp - tbl_unsupp # 32: fsincos + long tbl_unsupp - tbl_unsupp # 33: fsincos + long tbl_unsupp - tbl_unsupp # 34: fsincos + long tbl_unsupp - tbl_unsupp # 35: fsincos + long tbl_unsupp - tbl_unsupp # 36: fsincos + long tbl_unsupp - tbl_unsupp # 37: fsincos + long fcmp - tbl_unsupp # 38: fcmp + long tbl_unsupp - tbl_unsupp + long ftst - tbl_unsupp # 3a: ftst + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long fsin - tbl_unsupp # 40: fsmove + long fssqrt - tbl_unsupp # 41: fssqrt + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long fdin - tbl_unsupp # 44: fdmove + long fdsqrt - tbl_unsupp # 45: fdsqrt + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long fsabs - tbl_unsupp # 58: fsabs + long tbl_unsupp - tbl_unsupp + long fsneg - tbl_unsupp # 5a: fsneg + long tbl_unsupp - tbl_unsupp + long fdabs - tbl_unsupp # 5c: fdabs + long tbl_unsupp - tbl_unsupp + long fdneg - tbl_unsupp # 5e: fdneg + long tbl_unsupp - tbl_unsupp + long fsdiv - tbl_unsupp # 60: fsdiv + long tbl_unsupp - tbl_unsupp + long fsadd - tbl_unsupp # 62: fsadd + long fsmul - tbl_unsupp # 63: fsmul + long fddiv - tbl_unsupp # 64: fddiv + long tbl_unsupp - tbl_unsupp + long fdadd - tbl_unsupp # 66: fdadd + long fdmul - tbl_unsupp # 67: fdmul + long fssub - tbl_unsupp # 68: fssub + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long tbl_unsupp - tbl_unsupp + long fdsub - tbl_unsupp # 6c: fdsub + +################################################# +# Add this here so non-fp modules can compile. +# (smovcr is called from fpsp_inex.) + global smovcr +smovcr: + bra.b smovcr + +######################################################################### +# XDEF **************************************************************** # +# fmovm_dynamic(): emulate "fmovm" dynamic instruction # +# # +# XREF **************************************************************** # +# fetch_dreg() - fetch data register # +# {i,d,}mem_read() - fetch data from memory # +# _mem_write() - write data to memory # +# iea_iacc() - instruction memory access error occurred # +# iea_dacc() - data memory access error occurred # +# restore() - restore An index regs if access error occurred # +# # +# INPUT *************************************************************** # +# None # +# # +# OUTPUT ************************************************************** # +# If instr is "fmovm Dn,-(A7)" from supervisor mode, # +# d0 = size of dump # +# d1 = Dn # +# Else if instruction access error, # +# d0 = FSLW # +# Else if data access error, # +# d0 = FSLW # +# a0 = address of fault # +# Else # +# none. # +# # +# ALGORITHM *********************************************************** # +# The effective address must be calculated since this is entered # +# from an "Unimplemented Effective Address" exception handler. So, we # +# have our own fcalc_ea() routine here. If an access error is flagged # +# by a _{i,d,}mem_read() call, we must exit through the special # +# handler. # +# The data register is determined and its value loaded to get the # +# string of FP registers affected. This value is used as an index into # +# a lookup table such that we can determine the number of bytes # +# involved. # +# If the instruction is "fmovm.x <ea>,Dn", a _mem_read() is used # +# to read in all FP values. Again, _mem_read() may fail and require a # +# special exit. # +# If the instruction is "fmovm.x DN,<ea>", a _mem_write() is used # +# to write all FP values. _mem_write() may also fail. # +# If the instruction is "fmovm.x DN,-(a7)" from supervisor mode, # +# then we return the size of the dump and the string to the caller # +# so that the move can occur outside of this routine. This special # +# case is required so that moves to the system stack are handled # +# correctly. # +# # +# DYNAMIC: # +# fmovm.x dn, <ea> # +# fmovm.x <ea>, dn # +# # +# <WORD 1> <WORD2> # +# 1111 0010 00 |<ea>| 11@& 1000 0$$$ 0000 # +# # +# & = (0): predecrement addressing mode # +# (1): postincrement or control addressing mode # +# @ = (0): move listed regs from memory to the FPU # +# (1): move listed regs from the FPU to memory # +# $$$ : index of data register holding reg select mask # +# # +# NOTES: # +# If the data register holds a zero, then the # +# instruction is a nop. # +# # +######################################################################### + + global fmovm_dynamic +fmovm_dynamic: + +# extract the data register in which the bit string resides... + mov.b 1+EXC_EXTWORD(%a6),%d1 # fetch extword + andi.w &0x70,%d1 # extract reg bits + lsr.b &0x4,%d1 # shift into lo bits + +# fetch the bit string into d0... + bsr.l fetch_dreg # fetch reg string + + andi.l &0x000000ff,%d0 # keep only lo byte + + mov.l %d0,-(%sp) # save strg + mov.b (tbl_fmovm_size.w,%pc,%d0),%d0 + mov.l %d0,-(%sp) # save size + bsr.l fmovm_calc_ea # calculate <ea> + mov.l (%sp)+,%d0 # restore size + mov.l (%sp)+,%d1 # restore strg + +# if the bit string is a zero, then the operation is a no-op +# but, make sure that we've calculated ea and advanced the opword pointer + beq.w fmovm_data_done + +# separate move ins from move outs... + btst &0x5,EXC_EXTWORD(%a6) # is it a move in or out? + beq.w fmovm_data_in # it's a move out + +############# +# MOVE OUT: # +############# +fmovm_data_out: + btst &0x4,EXC_EXTWORD(%a6) # control or predecrement? + bne.w fmovm_out_ctrl # control + +############################ +fmovm_out_predec: +# for predecrement mode, the bit string is the opposite of both control +# operations and postincrement mode. (bit7 = FP7 ... bit0 = FP0) +# here, we convert it to be just like the others... + mov.b (tbl_fmovm_convert.w,%pc,%d1.w*1),%d1 + + btst &0x5,EXC_SR(%a6) # user or supervisor mode? + beq.b fmovm_out_ctrl # user + +fmovm_out_predec_s: + cmpi.b SPCOND_FLG(%a6),&mda7_flg # is <ea> mode -(a7)? + bne.b fmovm_out_ctrl + +# the operation was unfortunately an: fmovm.x dn,-(sp) +# called from supervisor mode. +# we're also passing "size" and "strg" back to the calling routine + rts + +############################ +fmovm_out_ctrl: + mov.l %a0,%a1 # move <ea> to a1 + + sub.l %d0,%sp # subtract size of dump + lea (%sp),%a0 + + tst.b %d1 # should FP0 be moved? + bpl.b fmovm_out_ctrl_fp1 # no + + mov.l 0x0+EXC_FP0(%a6),(%a0)+ # yes + mov.l 0x4+EXC_FP0(%a6),(%a0)+ + mov.l 0x8+EXC_FP0(%a6),(%a0)+ + +fmovm_out_ctrl_fp1: + lsl.b &0x1,%d1 # should FP1 be moved? + bpl.b fmovm_out_ctrl_fp2 # no + + mov.l 0x0+EXC_FP1(%a6),(%a0)+ # yes + mov.l 0x4+EXC_FP1(%a6),(%a0)+ + mov.l 0x8+EXC_FP1(%a6),(%a0)+ + +fmovm_out_ctrl_fp2: + lsl.b &0x1,%d1 # should FP2 be moved? + bpl.b fmovm_out_ctrl_fp3 # no + + fmovm.x &0x20,(%a0) # yes + add.l &0xc,%a0 + +fmovm_out_ctrl_fp3: + lsl.b &0x1,%d1 # should FP3 be moved? + bpl.b fmovm_out_ctrl_fp4 # no + + fmovm.x &0x10,(%a0) # yes + add.l &0xc,%a0 + +fmovm_out_ctrl_fp4: + lsl.b &0x1,%d1 # should FP4 be moved? + bpl.b fmovm_out_ctrl_fp5 # no + + fmovm.x &0x08,(%a0) # yes + add.l &0xc,%a0 + +fmovm_out_ctrl_fp5: + lsl.b &0x1,%d1 # should FP5 be moved? + bpl.b fmovm_out_ctrl_fp6 # no + + fmovm.x &0x04,(%a0) # yes + add.l &0xc,%a0 + +fmovm_out_ctrl_fp6: + lsl.b &0x1,%d1 # should FP6 be moved? + bpl.b fmovm_out_ctrl_fp7 # no + + fmovm.x &0x02,(%a0) # yes + add.l &0xc,%a0 + +fmovm_out_ctrl_fp7: + lsl.b &0x1,%d1 # should FP7 be moved? + bpl.b fmovm_out_ctrl_done # no + + fmovm.x &0x01,(%a0) # yes + add.l &0xc,%a0 + +fmovm_out_ctrl_done: + mov.l %a1,L_SCR1(%a6) + + lea (%sp),%a0 # pass: supervisor src + mov.l %d0,-(%sp) # save size + bsr.l _dmem_write # copy data to user mem + + mov.l (%sp)+,%d0 + add.l %d0,%sp # clear fpreg data from stack + + tst.l %d1 # did dstore err? + bne.w fmovm_out_err # yes + + rts + +############ +# MOVE IN: # +############ +fmovm_data_in: + mov.l %a0,L_SCR1(%a6) + + sub.l %d0,%sp # make room for fpregs + lea (%sp),%a1 + + mov.l %d1,-(%sp) # save bit string for later + mov.l %d0,-(%sp) # save # of bytes + + bsr.l _dmem_read # copy data from user mem + + mov.l (%sp)+,%d0 # retrieve # of bytes + + tst.l %d1 # did dfetch fail? + bne.w fmovm_in_err # yes + + mov.l (%sp)+,%d1 # load bit string + + lea (%sp),%a0 # addr of stack + + tst.b %d1 # should FP0 be moved? + bpl.b fmovm_data_in_fp1 # no + + mov.l (%a0)+,0x0+EXC_FP0(%a6) # yes + mov.l (%a0)+,0x4+EXC_FP0(%a6) + mov.l (%a0)+,0x8+EXC_FP0(%a6) + +fmovm_data_in_fp1: + lsl.b &0x1,%d1 # should FP1 be moved? + bpl.b fmovm_data_in_fp2 # no + + mov.l (%a0)+,0x0+EXC_FP1(%a6) # yes + mov.l (%a0)+,0x4+EXC_FP1(%a6) + mov.l (%a0)+,0x8+EXC_FP1(%a6) + +fmovm_data_in_fp2: + lsl.b &0x1,%d1 # should FP2 be moved? + bpl.b fmovm_data_in_fp3 # no + + fmovm.x (%a0)+,&0x20 # yes + +fmovm_data_in_fp3: + lsl.b &0x1,%d1 # should FP3 be moved? + bpl.b fmovm_data_in_fp4 # no + + fmovm.x (%a0)+,&0x10 # yes + +fmovm_data_in_fp4: + lsl.b &0x1,%d1 # should FP4 be moved? + bpl.b fmovm_data_in_fp5 # no + + fmovm.x (%a0)+,&0x08 # yes + +fmovm_data_in_fp5: + lsl.b &0x1,%d1 # should FP5 be moved? + bpl.b fmovm_data_in_fp6 # no + + fmovm.x (%a0)+,&0x04 # yes + +fmovm_data_in_fp6: + lsl.b &0x1,%d1 # should FP6 be moved? + bpl.b fmovm_data_in_fp7 # no + + fmovm.x (%a0)+,&0x02 # yes + +fmovm_data_in_fp7: + lsl.b &0x1,%d1 # should FP7 be moved? + bpl.b fmovm_data_in_done # no + + fmovm.x (%a0)+,&0x01 # yes + +fmovm_data_in_done: + add.l %d0,%sp # remove fpregs from stack + rts + +##################################### + +fmovm_data_done: + rts + +############################################################################## + +# +# table indexed by the operation's bit string that gives the number +# of bytes that will be moved. +# +# number of bytes = (# of 1's in bit string) * 12(bytes/fpreg) +# +tbl_fmovm_size: + byte 0x00,0x0c,0x0c,0x18,0x0c,0x18,0x18,0x24 + byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 + byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 + byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 + byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 + byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 + byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 + byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 + byte 0x3c,0x48,0x48,0x54,0x48,0x54,0x54,0x60 + +# +# table to convert a pre-decrement bit string into a post-increment +# or control bit string. +# ex: 0x00 ==> 0x00 +# 0x01 ==> 0x80 +# 0x02 ==> 0x40 +# . +# . +# 0xfd ==> 0xbf +# 0xfe ==> 0x7f +# 0xff ==> 0xff +# +tbl_fmovm_convert: + byte 0x00,0x80,0x40,0xc0,0x20,0xa0,0x60,0xe0 + byte 0x10,0x90,0x50,0xd0,0x30,0xb0,0x70,0xf0 + byte 0x08,0x88,0x48,0xc8,0x28,0xa8,0x68,0xe8 + byte 0x18,0x98,0x58,0xd8,0x38,0xb8,0x78,0xf8 + byte 0x04,0x84,0x44,0xc4,0x24,0xa4,0x64,0xe4 + byte 0x14,0x94,0x54,0xd4,0x34,0xb4,0x74,0xf4 + byte 0x0c,0x8c,0x4c,0xcc,0x2c,0xac,0x6c,0xec + byte 0x1c,0x9c,0x5c,0xdc,0x3c,0xbc,0x7c,0xfc + byte 0x02,0x82,0x42,0xc2,0x22,0xa2,0x62,0xe2 + byte 0x12,0x92,0x52,0xd2,0x32,0xb2,0x72,0xf2 + byte 0x0a,0x8a,0x4a,0xca,0x2a,0xaa,0x6a,0xea + byte 0x1a,0x9a,0x5a,0xda,0x3a,0xba,0x7a,0xfa + byte 0x06,0x86,0x46,0xc6,0x26,0xa6,0x66,0xe6 + byte 0x16,0x96,0x56,0xd6,0x36,0xb6,0x76,0xf6 + byte 0x0e,0x8e,0x4e,0xce,0x2e,0xae,0x6e,0xee + byte 0x1e,0x9e,0x5e,0xde,0x3e,0xbe,0x7e,0xfe + byte 0x01,0x81,0x41,0xc1,0x21,0xa1,0x61,0xe1 + byte 0x11,0x91,0x51,0xd1,0x31,0xb1,0x71,0xf1 + byte 0x09,0x89,0x49,0xc9,0x29,0xa9,0x69,0xe9 + byte 0x19,0x99,0x59,0xd9,0x39,0xb9,0x79,0xf9 + byte 0x05,0x85,0x45,0xc5,0x25,0xa5,0x65,0xe5 + byte 0x15,0x95,0x55,0xd5,0x35,0xb5,0x75,0xf5 + byte 0x0d,0x8d,0x4d,0xcd,0x2d,0xad,0x6d,0xed + byte 0x1d,0x9d,0x5d,0xdd,0x3d,0xbd,0x7d,0xfd + byte 0x03,0x83,0x43,0xc3,0x23,0xa3,0x63,0xe3 + byte 0x13,0x93,0x53,0xd3,0x33,0xb3,0x73,0xf3 + byte 0x0b,0x8b,0x4b,0xcb,0x2b,0xab,0x6b,0xeb + byte 0x1b,0x9b,0x5b,0xdb,0x3b,0xbb,0x7b,0xfb + byte 0x07,0x87,0x47,0xc7,0x27,0xa7,0x67,0xe7 + byte 0x17,0x97,0x57,0xd7,0x37,0xb7,0x77,0xf7 + byte 0x0f,0x8f,0x4f,0xcf,0x2f,0xaf,0x6f,0xef + byte 0x1f,0x9f,0x5f,0xdf,0x3f,0xbf,0x7f,0xff + + global fmovm_calc_ea +############################################### +# _fmovm_calc_ea: calculate effective address # +############################################### +fmovm_calc_ea: + mov.l %d0,%a0 # move # bytes to a0 + +# currently, MODE and REG are taken from the EXC_OPWORD. this could be +# easily changed if they were inputs passed in registers. + mov.w EXC_OPWORD(%a6),%d0 # fetch opcode word + mov.w %d0,%d1 # make a copy + + andi.w &0x3f,%d0 # extract mode field + andi.l &0x7,%d1 # extract reg field + +# jump to the corresponding function for each {MODE,REG} pair. + mov.w (tbl_fea_mode.b,%pc,%d0.w*2),%d0 # fetch jmp distance + jmp (tbl_fea_mode.b,%pc,%d0.w*1) # jmp to correct ea mode + + swbeg &64 +tbl_fea_mode: + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + + short faddr_ind_a0 - tbl_fea_mode + short faddr_ind_a1 - tbl_fea_mode + short faddr_ind_a2 - tbl_fea_mode + short faddr_ind_a3 - tbl_fea_mode + short faddr_ind_a4 - tbl_fea_mode + short faddr_ind_a5 - tbl_fea_mode + short faddr_ind_a6 - tbl_fea_mode + short faddr_ind_a7 - tbl_fea_mode + + short faddr_ind_p_a0 - tbl_fea_mode + short faddr_ind_p_a1 - tbl_fea_mode + short faddr_ind_p_a2 - tbl_fea_mode + short faddr_ind_p_a3 - tbl_fea_mode + short faddr_ind_p_a4 - tbl_fea_mode + short faddr_ind_p_a5 - tbl_fea_mode + short faddr_ind_p_a6 - tbl_fea_mode + short faddr_ind_p_a7 - tbl_fea_mode + + short faddr_ind_m_a0 - tbl_fea_mode + short faddr_ind_m_a1 - tbl_fea_mode + short faddr_ind_m_a2 - tbl_fea_mode + short faddr_ind_m_a3 - tbl_fea_mode + short faddr_ind_m_a4 - tbl_fea_mode + short faddr_ind_m_a5 - tbl_fea_mode + short faddr_ind_m_a6 - tbl_fea_mode + short faddr_ind_m_a7 - tbl_fea_mode + + short faddr_ind_disp_a0 - tbl_fea_mode + short faddr_ind_disp_a1 - tbl_fea_mode + short faddr_ind_disp_a2 - tbl_fea_mode + short faddr_ind_disp_a3 - tbl_fea_mode + short faddr_ind_disp_a4 - tbl_fea_mode + short faddr_ind_disp_a5 - tbl_fea_mode + short faddr_ind_disp_a6 - tbl_fea_mode + short faddr_ind_disp_a7 - tbl_fea_mode + + short faddr_ind_ext - tbl_fea_mode + short faddr_ind_ext - tbl_fea_mode + short faddr_ind_ext - tbl_fea_mode + short faddr_ind_ext - tbl_fea_mode + short faddr_ind_ext - tbl_fea_mode + short faddr_ind_ext - tbl_fea_mode + short faddr_ind_ext - tbl_fea_mode + short faddr_ind_ext - tbl_fea_mode + + short fabs_short - tbl_fea_mode + short fabs_long - tbl_fea_mode + short fpc_ind - tbl_fea_mode + short fpc_ind_ext - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + short tbl_fea_mode - tbl_fea_mode + +################################### +# Address register indirect: (An) # +################################### +faddr_ind_a0: + mov.l EXC_DREGS+0x8(%a6),%a0 # Get current a0 + rts + +faddr_ind_a1: + mov.l EXC_DREGS+0xc(%a6),%a0 # Get current a1 + rts + +faddr_ind_a2: + mov.l %a2,%a0 # Get current a2 + rts + +faddr_ind_a3: + mov.l %a3,%a0 # Get current a3 + rts + +faddr_ind_a4: + mov.l %a4,%a0 # Get current a4 + rts + +faddr_ind_a5: + mov.l %a5,%a0 # Get current a5 + rts + +faddr_ind_a6: + mov.l (%a6),%a0 # Get current a6 + rts + +faddr_ind_a7: + mov.l EXC_A7(%a6),%a0 # Get current a7 + rts + +##################################################### +# Address register indirect w/ postincrement: (An)+ # +##################################################### +faddr_ind_p_a0: + mov.l EXC_DREGS+0x8(%a6),%d0 # Get current a0 + mov.l %d0,%d1 + add.l %a0,%d1 # Increment + mov.l %d1,EXC_DREGS+0x8(%a6) # Save incr value + mov.l %d0,%a0 + rts + +faddr_ind_p_a1: + mov.l EXC_DREGS+0xc(%a6),%d0 # Get current a1 + mov.l %d0,%d1 + add.l %a0,%d1 # Increment + mov.l %d1,EXC_DREGS+0xc(%a6) # Save incr value + mov.l %d0,%a0 + rts + +faddr_ind_p_a2: + mov.l %a2,%d0 # Get current a2 + mov.l %d0,%d1 + add.l %a0,%d1 # Increment + mov.l %d1,%a2 # Save incr value + mov.l %d0,%a0 + rts + +faddr_ind_p_a3: + mov.l %a3,%d0 # Get current a3 + mov.l %d0,%d1 + add.l %a0,%d1 # Increment + mov.l %d1,%a3 # Save incr value + mov.l %d0,%a0 + rts + +faddr_ind_p_a4: + mov.l %a4,%d0 # Get current a4 + mov.l %d0,%d1 + add.l %a0,%d1 # Increment + mov.l %d1,%a4 # Save incr value + mov.l %d0,%a0 + rts + +faddr_ind_p_a5: + mov.l %a5,%d0 # Get current a5 + mov.l %d0,%d1 + add.l %a0,%d1 # Increment + mov.l %d1,%a5 # Save incr value + mov.l %d0,%a0 + rts + +faddr_ind_p_a6: + mov.l (%a6),%d0 # Get current a6 + mov.l %d0,%d1 + add.l %a0,%d1 # Increment + mov.l %d1,(%a6) # Save incr value + mov.l %d0,%a0 + rts + +faddr_ind_p_a7: + mov.b &mia7_flg,SPCOND_FLG(%a6) # set "special case" flag + + mov.l EXC_A7(%a6),%d0 # Get current a7 + mov.l %d0,%d1 + add.l %a0,%d1 # Increment + mov.l %d1,EXC_A7(%a6) # Save incr value + mov.l %d0,%a0 + rts + +#################################################### +# Address register indirect w/ predecrement: -(An) # +#################################################### +faddr_ind_m_a0: + mov.l EXC_DREGS+0x8(%a6),%d0 # Get current a0 + sub.l %a0,%d0 # Decrement + mov.l %d0,EXC_DREGS+0x8(%a6) # Save decr value + mov.l %d0,%a0 + rts + +faddr_ind_m_a1: + mov.l EXC_DREGS+0xc(%a6),%d0 # Get current a1 + sub.l %a0,%d0 # Decrement + mov.l %d0,EXC_DREGS+0xc(%a6) # Save decr value + mov.l %d0,%a0 + rts + +faddr_ind_m_a2: + mov.l %a2,%d0 # Get current a2 + sub.l %a0,%d0 # Decrement + mov.l %d0,%a2 # Save decr value + mov.l %d0,%a0 + rts + +faddr_ind_m_a3: + mov.l %a3,%d0 # Get current a3 + sub.l %a0,%d0 # Decrement + mov.l %d0,%a3 # Save decr value + mov.l %d0,%a0 + rts + +faddr_ind_m_a4: + mov.l %a4,%d0 # Get current a4 + sub.l %a0,%d0 # Decrement + mov.l %d0,%a4 # Save decr value + mov.l %d0,%a0 + rts + +faddr_ind_m_a5: + mov.l %a5,%d0 # Get current a5 + sub.l %a0,%d0 # Decrement + mov.l %d0,%a5 # Save decr value + mov.l %d0,%a0 + rts + +faddr_ind_m_a6: + mov.l (%a6),%d0 # Get current a6 + sub.l %a0,%d0 # Decrement + mov.l %d0,(%a6) # Save decr value + mov.l %d0,%a0 + rts + +faddr_ind_m_a7: + mov.b &mda7_flg,SPCOND_FLG(%a6) # set "special case" flag + + mov.l EXC_A7(%a6),%d0 # Get current a7 + sub.l %a0,%d0 # Decrement + mov.l %d0,EXC_A7(%a6) # Save decr value + mov.l %d0,%a0 + rts + +######################################################## +# Address register indirect w/ displacement: (d16, An) # +######################################################## +faddr_ind_disp_a0: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # sign extend displacement + + add.l EXC_DREGS+0x8(%a6),%a0 # a0 + d16 + rts + +faddr_ind_disp_a1: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # sign extend displacement + + add.l EXC_DREGS+0xc(%a6),%a0 # a1 + d16 + rts + +faddr_ind_disp_a2: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # sign extend displacement + + add.l %a2,%a0 # a2 + d16 + rts + +faddr_ind_disp_a3: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # sign extend displacement + + add.l %a3,%a0 # a3 + d16 + rts + +faddr_ind_disp_a4: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # sign extend displacement + + add.l %a4,%a0 # a4 + d16 + rts + +faddr_ind_disp_a5: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # sign extend displacement + + add.l %a5,%a0 # a5 + d16 + rts + +faddr_ind_disp_a6: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # sign extend displacement + + add.l (%a6),%a0 # a6 + d16 + rts + +faddr_ind_disp_a7: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # sign extend displacement + + add.l EXC_A7(%a6),%a0 # a7 + d16 + rts + +######################################################################## +# Address register indirect w/ index(8-bit displacement): (d8, An, Xn) # +# " " " w/ " (base displacement): (bd, An, Xn) # +# Memory indirect postindexed: ([bd, An], Xn, od) # +# Memory indirect preindexed: ([bd, An, Xn], od) # +######################################################################## +faddr_ind_ext: + addq.l &0x8,%d1 + bsr.l fetch_dreg # fetch base areg + mov.l %d0,-(%sp) + + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word # fetch extword in d0 + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l (%sp)+,%a0 + + btst &0x8,%d0 + bne.w fcalc_mem_ind + + mov.l %d0,L_SCR1(%a6) # hold opword + + mov.l %d0,%d1 + rol.w &0x4,%d1 + andi.w &0xf,%d1 # extract index regno + +# count on fetch_dreg() not to alter a0... + bsr.l fetch_dreg # fetch index + + mov.l %d2,-(%sp) # save d2 + mov.l L_SCR1(%a6),%d2 # fetch opword + + btst &0xb,%d2 # is it word or long? + bne.b faii8_long + ext.l %d0 # sign extend word index +faii8_long: + mov.l %d2,%d1 + rol.w &0x7,%d1 + andi.l &0x3,%d1 # extract scale value + + lsl.l %d1,%d0 # shift index by scale + + extb.l %d2 # sign extend displacement + add.l %d2,%d0 # index + disp + add.l %d0,%a0 # An + (index + disp) + + mov.l (%sp)+,%d2 # restore old d2 + rts + +########################### +# Absolute short: (XXX).W # +########################### +fabs_short: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word # fetch short address + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # return <ea> in a0 + rts + +########################## +# Absolute long: (XXX).L # +########################## +fabs_long: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch long address + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,%a0 # return <ea> in a0 + rts + +####################################################### +# Program counter indirect w/ displacement: (d16, PC) # +####################################################### +fpc_ind: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word # fetch word displacement + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.w %d0,%a0 # sign extend displacement + + add.l EXC_EXTWPTR(%a6),%a0 # pc + d16 + +# _imem_read_word() increased the extwptr by 2. need to adjust here. + subq.l &0x2,%a0 # adjust <ea> + rts + +########################################################## +# PC indirect w/ index(8-bit displacement): (d8, PC, An) # +# " " w/ " (base displacement): (bd, PC, An) # +# PC memory indirect postindexed: ([bd, PC], Xn, od) # +# PC memory indirect preindexed: ([bd, PC, Xn], od) # +########################################################## +fpc_ind_ext: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word # fetch ext word + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l EXC_EXTWPTR(%a6),%a0 # put base in a0 + subq.l &0x2,%a0 # adjust base + + btst &0x8,%d0 # is disp only 8 bits? + bne.w fcalc_mem_ind # calc memory indirect + + mov.l %d0,L_SCR1(%a6) # store opword + + mov.l %d0,%d1 # make extword copy + rol.w &0x4,%d1 # rotate reg num into place + andi.w &0xf,%d1 # extract register number + +# count on fetch_dreg() not to alter a0... + bsr.l fetch_dreg # fetch index + + mov.l %d2,-(%sp) # save d2 + mov.l L_SCR1(%a6),%d2 # fetch opword + + btst &0xb,%d2 # is index word or long? + bne.b fpii8_long # long + ext.l %d0 # sign extend word index +fpii8_long: + mov.l %d2,%d1 + rol.w &0x7,%d1 # rotate scale value into place + andi.l &0x3,%d1 # extract scale value + + lsl.l %d1,%d0 # shift index by scale + + extb.l %d2 # sign extend displacement + add.l %d2,%d0 # disp + index + add.l %d0,%a0 # An + (index + disp) + + mov.l (%sp)+,%d2 # restore temp register + rts + +# d2 = index +# d3 = base +# d4 = od +# d5 = extword +fcalc_mem_ind: + btst &0x6,%d0 # is the index suppressed? + beq.b fcalc_index + + movm.l &0x3c00,-(%sp) # save d2-d5 + + mov.l %d0,%d5 # put extword in d5 + mov.l %a0,%d3 # put base in d3 + + clr.l %d2 # yes, so index = 0 + bra.b fbase_supp_ck + +# index: +fcalc_index: + mov.l %d0,L_SCR1(%a6) # save d0 (opword) + bfextu %d0{&16:&4},%d1 # fetch dreg index + bsr.l fetch_dreg + + movm.l &0x3c00,-(%sp) # save d2-d5 + mov.l %d0,%d2 # put index in d2 + mov.l L_SCR1(%a6),%d5 + mov.l %a0,%d3 + + btst &0xb,%d5 # is index word or long? + bne.b fno_ext + ext.l %d2 + +fno_ext: + bfextu %d5{&21:&2},%d0 + lsl.l %d0,%d2 + +# base address (passed as parameter in d3): +# we clear the value here if it should actually be suppressed. +fbase_supp_ck: + btst &0x7,%d5 # is the bd suppressed? + beq.b fno_base_sup + clr.l %d3 + +# base displacement: +fno_base_sup: + bfextu %d5{&26:&2},%d0 # get bd size +# beq.l fmovm_error # if (size == 0) it's reserved + + cmpi.b %d0,&0x2 + blt.b fno_bd + beq.b fget_word_bd + + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long + + tst.l %d1 # did ifetch fail? + bne.l fcea_iacc # yes + + bra.b fchk_ind + +fget_word_bd: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l fcea_iacc # yes + + ext.l %d0 # sign extend bd + +fchk_ind: + add.l %d0,%d3 # base += bd + +# outer displacement: +fno_bd: + bfextu %d5{&30:&2},%d0 # is od suppressed? + beq.w faii_bd + + cmpi.b %d0,&0x2 + blt.b fnull_od + beq.b fword_od + + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long + + tst.l %d1 # did ifetch fail? + bne.l fcea_iacc # yes + + bra.b fadd_them + +fword_od: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_word + + tst.l %d1 # did ifetch fail? + bne.l fcea_iacc # yes + + ext.l %d0 # sign extend od + bra.b fadd_them + +fnull_od: + clr.l %d0 + +fadd_them: + mov.l %d0,%d4 + + btst &0x2,%d5 # pre or post indexing? + beq.b fpre_indexed + + mov.l %d3,%a0 + bsr.l _dmem_read_long + + tst.l %d1 # did dfetch fail? + bne.w fcea_err # yes + + add.l %d2,%d0 # <ea> += index + add.l %d4,%d0 # <ea> += od + bra.b fdone_ea + +fpre_indexed: + add.l %d2,%d3 # preindexing + mov.l %d3,%a0 + bsr.l _dmem_read_long + + tst.l %d1 # did dfetch fail? + bne.w fcea_err # yes + + add.l %d4,%d0 # ea += od + bra.b fdone_ea + +faii_bd: + add.l %d2,%d3 # ea = (base + bd) + index + mov.l %d3,%d0 +fdone_ea: + mov.l %d0,%a0 + + movm.l (%sp)+,&0x003c # restore d2-d5 + rts + +######################################################### +fcea_err: + mov.l %d3,%a0 + + movm.l (%sp)+,&0x003c # restore d2-d5 + mov.w &0x0101,%d0 + bra.l iea_dacc + +fcea_iacc: + movm.l (%sp)+,&0x003c # restore d2-d5 + bra.l iea_iacc + +fmovm_out_err: + bsr.l restore + mov.w &0x00e1,%d0 + bra.b fmovm_err + +fmovm_in_err: + bsr.l restore + mov.w &0x0161,%d0 + +fmovm_err: + mov.l L_SCR1(%a6),%a0 + bra.l iea_dacc + +######################################################################### +# XDEF **************************************************************** # +# fmovm_ctrl(): emulate fmovm.l of control registers instr # +# # +# XREF **************************************************************** # +# _imem_read_long() - read longword from memory # +# iea_iacc() - _imem_read_long() failed; error recovery # +# # +# INPUT *************************************************************** # +# None # +# # +# OUTPUT ************************************************************** # +# If _imem_read_long() doesn't fail: # +# USER_FPCR(a6) = new FPCR value # +# USER_FPSR(a6) = new FPSR value # +# USER_FPIAR(a6) = new FPIAR value # +# # +# ALGORITHM *********************************************************** # +# Decode the instruction type by looking at the extension word # +# in order to see how many control registers to fetch from memory. # +# Fetch them using _imem_read_long(). If this fetch fails, exit through # +# the special access error exit handler iea_iacc(). # +# # +# Instruction word decoding: # +# # +# fmovem.l #<data>, {FPIAR&|FPCR&|FPSR} # +# # +# WORD1 WORD2 # +# 1111 0010 00 111100 100$ $$00 0000 0000 # +# # +# $$$ (100): FPCR # +# (010): FPSR # +# (001): FPIAR # +# (000): FPIAR # +# # +######################################################################### + + global fmovm_ctrl +fmovm_ctrl: + mov.b EXC_EXTWORD(%a6),%d0 # fetch reg select bits + cmpi.b %d0,&0x9c # fpcr & fpsr & fpiar ? + beq.w fctrl_in_7 # yes + cmpi.b %d0,&0x98 # fpcr & fpsr ? + beq.w fctrl_in_6 # yes + cmpi.b %d0,&0x94 # fpcr & fpiar ? + beq.b fctrl_in_5 # yes + +# fmovem.l #<data>, fpsr/fpiar +fctrl_in_3: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch FPSR from mem + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,USER_FPSR(%a6) # store new FPSR to stack + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch FPIAR from mem + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,USER_FPIAR(%a6) # store new FPIAR to stack + rts + +# fmovem.l #<data>, fpcr/fpiar +fctrl_in_5: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch FPCR from mem + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,USER_FPCR(%a6) # store new FPCR to stack + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch FPIAR from mem + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,USER_FPIAR(%a6) # store new FPIAR to stack + rts + +# fmovem.l #<data>, fpcr/fpsr +fctrl_in_6: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch FPCR from mem + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,USER_FPCR(%a6) # store new FPCR to mem + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch FPSR from mem + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,USER_FPSR(%a6) # store new FPSR to mem + rts + +# fmovem.l #<data>, fpcr/fpsr/fpiar +fctrl_in_7: + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch FPCR from mem + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,USER_FPCR(%a6) # store new FPCR to mem + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch FPSR from mem + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,USER_FPSR(%a6) # store new FPSR to mem + mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr + addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr + bsr.l _imem_read_long # fetch FPIAR from mem + + tst.l %d1 # did ifetch fail? + bne.l iea_iacc # yes + + mov.l %d0,USER_FPIAR(%a6) # store new FPIAR to mem + rts + +########################################################################## + +######################################################################### +# XDEF **************************************************************** # +# addsub_scaler2(): scale inputs to fadd/fsub such that no # +# OVFL/UNFL exceptions will result # +# # +# XREF **************************************************************** # +# norm() - normalize mantissa after adjusting exponent # +# # +# INPUT *************************************************************** # +# FP_SRC(a6) = fp op1(src) # +# FP_DST(a6) = fp op2(dst) # +# # +# OUTPUT ************************************************************** # +# FP_SRC(a6) = fp op1 scaled(src) # +# FP_DST(a6) = fp op2 scaled(dst) # +# d0 = scale amount # +# # +# ALGORITHM *********************************************************** # +# If the DST exponent is > the SRC exponent, set the DST exponent # +# equal to 0x3fff and scale the SRC exponent by the value that the # +# DST exponent was scaled by. If the SRC exponent is greater or equal, # +# do the opposite. Return this scale factor in d0. # +# If the two exponents differ by > the number of mantissa bits # +# plus two, then set the smallest exponent to a very small value as a # +# quick shortcut. # +# # +######################################################################### + + global addsub_scaler2 +addsub_scaler2: + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l DST_HI(%a1),FP_SCR1_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + mov.l DST_LO(%a1),FP_SCR1_LO(%a6) + mov.w SRC_EX(%a0),%d0 + mov.w DST_EX(%a1),%d1 + mov.w %d0,FP_SCR0_EX(%a6) + mov.w %d1,FP_SCR1_EX(%a6) + + andi.w &0x7fff,%d0 + andi.w &0x7fff,%d1 + mov.w %d0,L_SCR1(%a6) # store src exponent + mov.w %d1,2+L_SCR1(%a6) # store dst exponent + + cmp.w %d0, %d1 # is src exp >= dst exp? + bge.l src_exp_ge2 + +# dst exp is > src exp; scale dst to exp = 0x3fff +dst_exp_gt2: + bsr.l scale_to_zero_dst + mov.l %d0,-(%sp) # save scale factor + + cmpi.b STAG(%a6),&DENORM # is dst denormalized? + bne.b cmpexp12 + + lea FP_SCR0(%a6),%a0 + bsr.l norm # normalize the denorm; result is new exp + neg.w %d0 # new exp = -(shft val) + mov.w %d0,L_SCR1(%a6) # inset new exp + +cmpexp12: + mov.w 2+L_SCR1(%a6),%d0 + subi.w &mantissalen+2,%d0 # subtract mantissalen+2 from larger exp + + cmp.w %d0,L_SCR1(%a6) # is difference >= len(mantissa)+2? + bge.b quick_scale12 + + mov.w L_SCR1(%a6),%d0 + add.w 0x2(%sp),%d0 # scale src exponent by scale factor + mov.w FP_SCR0_EX(%a6),%d1 + and.w &0x8000,%d1 + or.w %d1,%d0 # concat {sgn,new exp} + mov.w %d0,FP_SCR0_EX(%a6) # insert new dst exponent + + mov.l (%sp)+,%d0 # return SCALE factor + rts + +quick_scale12: + andi.w &0x8000,FP_SCR0_EX(%a6) # zero src exponent + bset &0x0,1+FP_SCR0_EX(%a6) # set exp = 1 + + mov.l (%sp)+,%d0 # return SCALE factor + rts + +# src exp is >= dst exp; scale src to exp = 0x3fff +src_exp_ge2: + bsr.l scale_to_zero_src + mov.l %d0,-(%sp) # save scale factor + + cmpi.b DTAG(%a6),&DENORM # is dst denormalized? + bne.b cmpexp22 + lea FP_SCR1(%a6),%a0 + bsr.l norm # normalize the denorm; result is new exp + neg.w %d0 # new exp = -(shft val) + mov.w %d0,2+L_SCR1(%a6) # inset new exp + +cmpexp22: + mov.w L_SCR1(%a6),%d0 + subi.w &mantissalen+2,%d0 # subtract mantissalen+2 from larger exp + + cmp.w %d0,2+L_SCR1(%a6) # is difference >= len(mantissa)+2? + bge.b quick_scale22 + + mov.w 2+L_SCR1(%a6),%d0 + add.w 0x2(%sp),%d0 # scale dst exponent by scale factor + mov.w FP_SCR1_EX(%a6),%d1 + andi.w &0x8000,%d1 + or.w %d1,%d0 # concat {sgn,new exp} + mov.w %d0,FP_SCR1_EX(%a6) # insert new dst exponent + + mov.l (%sp)+,%d0 # return SCALE factor + rts + +quick_scale22: + andi.w &0x8000,FP_SCR1_EX(%a6) # zero dst exponent + bset &0x0,1+FP_SCR1_EX(%a6) # set exp = 1 + + mov.l (%sp)+,%d0 # return SCALE factor + rts + +########################################################################## + +######################################################################### +# XDEF **************************************************************** # +# scale_to_zero_src(): scale the exponent of extended precision # +# value at FP_SCR0(a6). # +# # +# XREF **************************************************************** # +# norm() - normalize the mantissa if the operand was a DENORM # +# # +# INPUT *************************************************************** # +# FP_SCR0(a6) = extended precision operand to be scaled # +# # +# OUTPUT ************************************************************** # +# FP_SCR0(a6) = scaled extended precision operand # +# d0 = scale value # +# # +# ALGORITHM *********************************************************** # +# Set the exponent of the input operand to 0x3fff. Save the value # +# of the difference between the original and new exponent. Then, # +# normalize the operand if it was a DENORM. Add this normalization # +# value to the previous value. Return the result. # +# # +######################################################################### + + global scale_to_zero_src +scale_to_zero_src: + mov.w FP_SCR0_EX(%a6),%d1 # extract operand's {sgn,exp} + mov.w %d1,%d0 # make a copy + + andi.l &0x7fff,%d1 # extract operand's exponent + + andi.w &0x8000,%d0 # extract operand's sgn + or.w &0x3fff,%d0 # insert new operand's exponent(=0) + + mov.w %d0,FP_SCR0_EX(%a6) # insert biased exponent + + cmpi.b STAG(%a6),&DENORM # is operand normalized? + beq.b stzs_denorm # normalize the DENORM + +stzs_norm: + mov.l &0x3fff,%d0 + sub.l %d1,%d0 # scale = BIAS + (-exp) + + rts + +stzs_denorm: + lea FP_SCR0(%a6),%a0 # pass ptr to src op + bsr.l norm # normalize denorm + neg.l %d0 # new exponent = -(shft val) + mov.l %d0,%d1 # prepare for op_norm call + bra.b stzs_norm # finish scaling + +### + +######################################################################### +# XDEF **************************************************************** # +# scale_sqrt(): scale the input operand exponent so a subsequent # +# fsqrt operation won't take an exception. # +# # +# XREF **************************************************************** # +# norm() - normalize the mantissa if the operand was a DENORM # +# # +# INPUT *************************************************************** # +# FP_SCR0(a6) = extended precision operand to be scaled # +# # +# OUTPUT ************************************************************** # +# FP_SCR0(a6) = scaled extended precision operand # +# d0 = scale value # +# # +# ALGORITHM *********************************************************** # +# If the input operand is a DENORM, normalize it. # +# If the exponent of the input operand is even, set the exponent # +# to 0x3ffe and return a scale factor of "(exp-0x3ffe)/2". If the # +# exponent of the input operand is off, set the exponent to ox3fff and # +# return a scale factor of "(exp-0x3fff)/2". # +# # +######################################################################### + + global scale_sqrt +scale_sqrt: + cmpi.b STAG(%a6),&DENORM # is operand normalized? + beq.b ss_denorm # normalize the DENORM + + mov.w FP_SCR0_EX(%a6),%d1 # extract operand's {sgn,exp} + andi.l &0x7fff,%d1 # extract operand's exponent + + andi.w &0x8000,FP_SCR0_EX(%a6) # extract operand's sgn + + btst &0x0,%d1 # is exp even or odd? + beq.b ss_norm_even + + ori.w &0x3fff,FP_SCR0_EX(%a6) # insert new operand's exponent(=0) + + mov.l &0x3fff,%d0 + sub.l %d1,%d0 # scale = BIAS + (-exp) + asr.l &0x1,%d0 # divide scale factor by 2 + rts + +ss_norm_even: + ori.w &0x3ffe,FP_SCR0_EX(%a6) # insert new operand's exponent(=0) + + mov.l &0x3ffe,%d0 + sub.l %d1,%d0 # scale = BIAS + (-exp) + asr.l &0x1,%d0 # divide scale factor by 2 + rts + +ss_denorm: + lea FP_SCR0(%a6),%a0 # pass ptr to src op + bsr.l norm # normalize denorm + + btst &0x0,%d0 # is exp even or odd? + beq.b ss_denorm_even + + ori.w &0x3fff,FP_SCR0_EX(%a6) # insert new operand's exponent(=0) + + add.l &0x3fff,%d0 + asr.l &0x1,%d0 # divide scale factor by 2 + rts + +ss_denorm_even: + ori.w &0x3ffe,FP_SCR0_EX(%a6) # insert new operand's exponent(=0) + + add.l &0x3ffe,%d0 + asr.l &0x1,%d0 # divide scale factor by 2 + rts + +### + +######################################################################### +# XDEF **************************************************************** # +# scale_to_zero_dst(): scale the exponent of extended precision # +# value at FP_SCR1(a6). # +# # +# XREF **************************************************************** # +# norm() - normalize the mantissa if the operand was a DENORM # +# # +# INPUT *************************************************************** # +# FP_SCR1(a6) = extended precision operand to be scaled # +# # +# OUTPUT ************************************************************** # +# FP_SCR1(a6) = scaled extended precision operand # +# d0 = scale value # +# # +# ALGORITHM *********************************************************** # +# Set the exponent of the input operand to 0x3fff. Save the value # +# of the difference between the original and new exponent. Then, # +# normalize the operand if it was a DENORM. Add this normalization # +# value to the previous value. Return the result. # +# # +######################################################################### + + global scale_to_zero_dst +scale_to_zero_dst: + mov.w FP_SCR1_EX(%a6),%d1 # extract operand's {sgn,exp} + mov.w %d1,%d0 # make a copy + + andi.l &0x7fff,%d1 # extract operand's exponent + + andi.w &0x8000,%d0 # extract operand's sgn + or.w &0x3fff,%d0 # insert new operand's exponent(=0) + + mov.w %d0,FP_SCR1_EX(%a6) # insert biased exponent + + cmpi.b DTAG(%a6),&DENORM # is operand normalized? + beq.b stzd_denorm # normalize the DENORM + +stzd_norm: + mov.l &0x3fff,%d0 + sub.l %d1,%d0 # scale = BIAS + (-exp) + rts + +stzd_denorm: + lea FP_SCR1(%a6),%a0 # pass ptr to dst op + bsr.l norm # normalize denorm + neg.l %d0 # new exponent = -(shft val) + mov.l %d0,%d1 # prepare for op_norm call + bra.b stzd_norm # finish scaling + +########################################################################## + +######################################################################### +# XDEF **************************************************************** # +# res_qnan(): return default result w/ QNAN operand for dyadic # +# res_snan(): return default result w/ SNAN operand for dyadic # +# res_qnan_1op(): return dflt result w/ QNAN operand for monadic # +# res_snan_1op(): return dflt result w/ SNAN operand for monadic # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# FP_SRC(a6) = pointer to extended precision src operand # +# FP_DST(a6) = pointer to extended precision dst operand # +# # +# OUTPUT ************************************************************** # +# fp0 = default result # +# # +# ALGORITHM *********************************************************** # +# If either operand (but not both operands) of an operation is a # +# nonsignalling NAN, then that NAN is returned as the result. If both # +# operands are nonsignalling NANs, then the destination operand # +# nonsignalling NAN is returned as the result. # +# If either operand to an operation is a signalling NAN (SNAN), # +# then, the SNAN bit is set in the FPSR EXC byte. If the SNAN trap # +# enable bit is set in the FPCR, then the trap is taken and the # +# destination is not modified. If the SNAN trap enable bit is not set, # +# then the SNAN is converted to a nonsignalling NAN (by setting the # +# SNAN bit in the operand to one), and the operation continues as # +# described in the preceding paragraph, for nonsignalling NANs. # +# Make sure the appropriate FPSR bits are set before exiting. # +# # +######################################################################### + + global res_qnan + global res_snan +res_qnan: +res_snan: + cmp.b DTAG(%a6), &SNAN # is the dst an SNAN? + beq.b dst_snan2 + cmp.b DTAG(%a6), &QNAN # is the dst a QNAN? + beq.b dst_qnan2 +src_nan: + cmp.b STAG(%a6), &QNAN + beq.b src_qnan2 + global res_snan_1op +res_snan_1op: +src_snan2: + bset &0x6, FP_SRC_HI(%a6) # set SNAN bit + or.l &nan_mask+aiop_mask+snan_mask, USER_FPSR(%a6) + lea FP_SRC(%a6), %a0 + bra.b nan_comp + global res_qnan_1op +res_qnan_1op: +src_qnan2: + or.l &nan_mask, USER_FPSR(%a6) + lea FP_SRC(%a6), %a0 + bra.b nan_comp +dst_snan2: + or.l &nan_mask+aiop_mask+snan_mask, USER_FPSR(%a6) + bset &0x6, FP_DST_HI(%a6) # set SNAN bit + lea FP_DST(%a6), %a0 + bra.b nan_comp +dst_qnan2: + lea FP_DST(%a6), %a0 + cmp.b STAG(%a6), &SNAN + bne nan_done + or.l &aiop_mask+snan_mask, USER_FPSR(%a6) +nan_done: + or.l &nan_mask, USER_FPSR(%a6) +nan_comp: + btst &0x7, FTEMP_EX(%a0) # is NAN neg? + beq.b nan_not_neg + or.l &neg_mask, USER_FPSR(%a6) +nan_not_neg: + fmovm.x (%a0), &0x80 + rts + +######################################################################### +# XDEF **************************************************************** # +# res_operr(): return default result during operand error # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# None # +# # +# OUTPUT ************************************************************** # +# fp0 = default operand error result # +# # +# ALGORITHM *********************************************************** # +# An nonsignalling NAN is returned as the default result when # +# an operand error occurs for the following cases: # +# # +# Multiply: (Infinity x Zero) # +# Divide : (Zero / Zero) || (Infinity / Infinity) # +# # +######################################################################### + + global res_operr +res_operr: + or.l &nan_mask+operr_mask+aiop_mask, USER_FPSR(%a6) + fmovm.x nan_return(%pc), &0x80 + rts + +nan_return: + long 0x7fff0000, 0xffffffff, 0xffffffff + +######################################################################### +# XDEF **************************************************************** # +# _denorm(): denormalize an intermediate result # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# a0 = points to the operand to be denormalized # +# (in the internal extended format) # +# # +# d0 = rounding precision # +# # +# OUTPUT ************************************************************** # +# a0 = pointer to the denormalized result # +# (in the internal extended format) # +# # +# d0 = guard,round,sticky # +# # +# ALGORITHM *********************************************************** # +# According to the exponent underflow threshold for the given # +# precision, shift the mantissa bits to the right in order raise the # +# exponent of the operand to the threshold value. While shifting the # +# mantissa bits right, maintain the value of the guard, round, and # +# sticky bits. # +# other notes: # +# (1) _denorm() is called by the underflow routines # +# (2) _denorm() does NOT affect the status register # +# # +######################################################################### + +# +# table of exponent threshold values for each precision +# +tbl_thresh: + short 0x0 + short sgl_thresh + short dbl_thresh + + global _denorm +_denorm: +# +# Load the exponent threshold for the precision selected and check +# to see if (threshold - exponent) is > 65 in which case we can +# simply calculate the sticky bit and zero the mantissa. otherwise +# we have to call the denormalization routine. +# + lsr.b &0x2, %d0 # shift prec to lo bits + mov.w (tbl_thresh.b,%pc,%d0.w*2), %d1 # load prec threshold + mov.w %d1, %d0 # copy d1 into d0 + sub.w FTEMP_EX(%a0), %d0 # diff = threshold - exp + cmpi.w %d0, &66 # is diff > 65? (mant + g,r bits) + bpl.b denorm_set_stky # yes; just calc sticky + + clr.l %d0 # clear g,r,s + btst &inex2_bit, FPSR_EXCEPT(%a6) # yes; was INEX2 set? + beq.b denorm_call # no; don't change anything + bset &29, %d0 # yes; set sticky bit + +denorm_call: + bsr.l dnrm_lp # denormalize the number + rts + +# +# all bit would have been shifted off during the denorm so simply +# calculate if the sticky should be set and clear the entire mantissa. +# +denorm_set_stky: + mov.l &0x20000000, %d0 # set sticky bit in return value + mov.w %d1, FTEMP_EX(%a0) # load exp with threshold + clr.l FTEMP_HI(%a0) # set d1 = 0 (ms mantissa) + clr.l FTEMP_LO(%a0) # set d2 = 0 (ms mantissa) + rts + +# # +# dnrm_lp(): normalize exponent/mantissa to specified threshold # +# # +# INPUT: # +# %a0 : points to the operand to be denormalized # +# %d0{31:29} : initial guard,round,sticky # +# %d1{15:0} : denormalization threshold # +# OUTPUT: # +# %a0 : points to the denormalized operand # +# %d0{31:29} : final guard,round,sticky # +# # + +# *** Local Equates *** # +set GRS, L_SCR2 # g,r,s temp storage +set FTEMP_LO2, L_SCR1 # FTEMP_LO copy + + global dnrm_lp +dnrm_lp: + +# +# make a copy of FTEMP_LO and place the g,r,s bits directly after it +# in memory so as to make the bitfield extraction for denormalization easier. +# + mov.l FTEMP_LO(%a0), FTEMP_LO2(%a6) # make FTEMP_LO copy + mov.l %d0, GRS(%a6) # place g,r,s after it + +# +# check to see how much less than the underflow threshold the operand +# exponent is. +# + mov.l %d1, %d0 # copy the denorm threshold + sub.w FTEMP_EX(%a0), %d1 # d1 = threshold - uns exponent + ble.b dnrm_no_lp # d1 <= 0 + cmpi.w %d1, &0x20 # is ( 0 <= d1 < 32) ? + blt.b case_1 # yes + cmpi.w %d1, &0x40 # is (32 <= d1 < 64) ? + blt.b case_2 # yes + bra.w case_3 # (d1 >= 64) + +# +# No normalization necessary +# +dnrm_no_lp: + mov.l GRS(%a6), %d0 # restore original g,r,s + rts + +# +# case (0<d1<32) +# +# %d0 = denorm threshold +# %d1 = "n" = amt to shift +# +# --------------------------------------------------------- +# | FTEMP_HI | FTEMP_LO |grs000.........000| +# --------------------------------------------------------- +# <-(32 - n)-><-(n)-><-(32 - n)-><-(n)-><-(32 - n)-><-(n)-> +# \ \ \ \ +# \ \ \ \ +# \ \ \ \ +# \ \ \ \ +# \ \ \ \ +# \ \ \ \ +# \ \ \ \ +# \ \ \ \ +# <-(n)-><-(32 - n)-><------(32)-------><------(32)-------> +# --------------------------------------------------------- +# |0.....0| NEW_HI | NEW_FTEMP_LO |grs | +# --------------------------------------------------------- +# +case_1: + mov.l %d2, -(%sp) # create temp storage + + mov.w %d0, FTEMP_EX(%a0) # exponent = denorm threshold + mov.l &32, %d0 + sub.w %d1, %d0 # %d0 = 32 - %d1 + + cmpi.w %d1, &29 # is shft amt >= 29 + blt.b case1_extract # no; no fix needed + mov.b GRS(%a6), %d2 + or.b %d2, 3+FTEMP_LO2(%a6) + +case1_extract: + bfextu FTEMP_HI(%a0){&0:%d0}, %d2 # %d2 = new FTEMP_HI + bfextu FTEMP_HI(%a0){%d0:&32}, %d1 # %d1 = new FTEMP_LO + bfextu FTEMP_LO2(%a6){%d0:&32}, %d0 # %d0 = new G,R,S + + mov.l %d2, FTEMP_HI(%a0) # store new FTEMP_HI + mov.l %d1, FTEMP_LO(%a0) # store new FTEMP_LO + + bftst %d0{&2:&30} # were bits shifted off? + beq.b case1_sticky_clear # no; go finish + bset &rnd_stky_bit, %d0 # yes; set sticky bit + +case1_sticky_clear: + and.l &0xe0000000, %d0 # clear all but G,R,S + mov.l (%sp)+, %d2 # restore temp register + rts + +# +# case (32<=d1<64) +# +# %d0 = denorm threshold +# %d1 = "n" = amt to shift +# +# --------------------------------------------------------- +# | FTEMP_HI | FTEMP_LO |grs000.........000| +# --------------------------------------------------------- +# <-(32 - n)-><-(n)-><-(32 - n)-><-(n)-><-(32 - n)-><-(n)-> +# \ \ \ +# \ \ \ +# \ \ ------------------- +# \ -------------------- \ +# ------------------- \ \ +# \ \ \ +# \ \ \ +# \ \ \ +# <-------(32)------><-(n)-><-(32 - n)-><------(32)-------> +# --------------------------------------------------------- +# |0...............0|0....0| NEW_LO |grs | +# --------------------------------------------------------- +# +case_2: + mov.l %d2, -(%sp) # create temp storage + + mov.w %d0, FTEMP_EX(%a0) # exponent = denorm threshold + subi.w &0x20, %d1 # %d1 now between 0 and 32 + mov.l &0x20, %d0 + sub.w %d1, %d0 # %d0 = 32 - %d1 + +# subtle step here; or in the g,r,s at the bottom of FTEMP_LO to minimize +# the number of bits to check for the sticky detect. +# it only plays a role in shift amounts of 61-63. + mov.b GRS(%a6), %d2 + or.b %d2, 3+FTEMP_LO2(%a6) + + bfextu FTEMP_HI(%a0){&0:%d0}, %d2 # %d2 = new FTEMP_LO + bfextu FTEMP_HI(%a0){%d0:&32}, %d1 # %d1 = new G,R,S + + bftst %d1{&2:&30} # were any bits shifted off? + bne.b case2_set_sticky # yes; set sticky bit + bftst FTEMP_LO2(%a6){%d0:&31} # were any bits shifted off? + bne.b case2_set_sticky # yes; set sticky bit + + mov.l %d1, %d0 # move new G,R,S to %d0 + bra.b case2_end + +case2_set_sticky: + mov.l %d1, %d0 # move new G,R,S to %d0 + bset &rnd_stky_bit, %d0 # set sticky bit + +case2_end: + clr.l FTEMP_HI(%a0) # store FTEMP_HI = 0 + mov.l %d2, FTEMP_LO(%a0) # store FTEMP_LO + and.l &0xe0000000, %d0 # clear all but G,R,S + + mov.l (%sp)+,%d2 # restore temp register + rts + +# +# case (d1>=64) +# +# %d0 = denorm threshold +# %d1 = amt to shift +# +case_3: + mov.w %d0, FTEMP_EX(%a0) # insert denorm threshold + + cmpi.w %d1, &65 # is shift amt > 65? + blt.b case3_64 # no; it's == 64 + beq.b case3_65 # no; it's == 65 + +# +# case (d1>65) +# +# Shift value is > 65 and out of range. All bits are shifted off. +# Return a zero mantissa with the sticky bit set +# + clr.l FTEMP_HI(%a0) # clear hi(mantissa) + clr.l FTEMP_LO(%a0) # clear lo(mantissa) + mov.l &0x20000000, %d0 # set sticky bit + rts + +# +# case (d1 == 64) +# +# --------------------------------------------------------- +# | FTEMP_HI | FTEMP_LO |grs000.........000| +# --------------------------------------------------------- +# <-------(32)------> +# \ \ +# \ \ +# \ \ +# \ ------------------------------ +# ------------------------------- \ +# \ \ +# \ \ +# \ \ +# <-------(32)------> +# --------------------------------------------------------- +# |0...............0|0................0|grs | +# --------------------------------------------------------- +# +case3_64: + mov.l FTEMP_HI(%a0), %d0 # fetch hi(mantissa) + mov.l %d0, %d1 # make a copy + and.l &0xc0000000, %d0 # extract G,R + and.l &0x3fffffff, %d1 # extract other bits + + bra.b case3_complete + +# +# case (d1 == 65) +# +# --------------------------------------------------------- +# | FTEMP_HI | FTEMP_LO |grs000.........000| +# --------------------------------------------------------- +# <-------(32)------> +# \ \ +# \ \ +# \ \ +# \ ------------------------------ +# -------------------------------- \ +# \ \ +# \ \ +# \ \ +# <-------(31)-----> +# --------------------------------------------------------- +# |0...............0|0................0|0rs | +# --------------------------------------------------------- +# +case3_65: + mov.l FTEMP_HI(%a0), %d0 # fetch hi(mantissa) + and.l &0x80000000, %d0 # extract R bit + lsr.l &0x1, %d0 # shift high bit into R bit + and.l &0x7fffffff, %d1 # extract other bits + +case3_complete: +# last operation done was an "and" of the bits shifted off so the condition +# codes are already set so branch accordingly. + bne.b case3_set_sticky # yes; go set new sticky + tst.l FTEMP_LO(%a0) # were any bits shifted off? + bne.b case3_set_sticky # yes; go set new sticky + tst.b GRS(%a6) # were any bits shifted off? + bne.b case3_set_sticky # yes; go set new sticky + +# +# no bits were shifted off so don't set the sticky bit. +# the guard and +# the entire mantissa is zero. +# + clr.l FTEMP_HI(%a0) # clear hi(mantissa) + clr.l FTEMP_LO(%a0) # clear lo(mantissa) + rts + +# +# some bits were shifted off so set the sticky bit. +# the entire mantissa is zero. +# +case3_set_sticky: + bset &rnd_stky_bit,%d0 # set new sticky bit + clr.l FTEMP_HI(%a0) # clear hi(mantissa) + clr.l FTEMP_LO(%a0) # clear lo(mantissa) + rts + +######################################################################### +# XDEF **************************************************************** # +# _round(): round result according to precision/mode # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# a0 = ptr to input operand in internal extended format # +# d1(hi) = contains rounding precision: # +# ext = $0000xxxx # +# sgl = $0004xxxx # +# dbl = $0008xxxx # +# d1(lo) = contains rounding mode: # +# RN = $xxxx0000 # +# RZ = $xxxx0001 # +# RM = $xxxx0002 # +# RP = $xxxx0003 # +# d0{31:29} = contains the g,r,s bits (extended) # +# # +# OUTPUT ************************************************************** # +# a0 = pointer to rounded result # +# # +# ALGORITHM *********************************************************** # +# On return the value pointed to by a0 is correctly rounded, # +# a0 is preserved and the g-r-s bits in d0 are cleared. # +# The result is not typed - the tag field is invalid. The # +# result is still in the internal extended format. # +# # +# The INEX bit of USER_FPSR will be set if the rounded result was # +# inexact (i.e. if any of the g-r-s bits were set). # +# # +######################################################################### + + global _round +_round: +# +# ext_grs() looks at the rounding precision and sets the appropriate +# G,R,S bits. +# If (G,R,S == 0) then result is exact and round is done, else set +# the inex flag in status reg and continue. +# + bsr.l ext_grs # extract G,R,S + + tst.l %d0 # are G,R,S zero? + beq.w truncate # yes; round is complete + + or.w &inx2a_mask, 2+USER_FPSR(%a6) # set inex2/ainex + +# +# Use rounding mode as an index into a jump table for these modes. +# All of the following assumes grs != 0. +# + mov.w (tbl_mode.b,%pc,%d1.w*2), %a1 # load jump offset + jmp (tbl_mode.b,%pc,%a1) # jmp to rnd mode handler + +tbl_mode: + short rnd_near - tbl_mode + short truncate - tbl_mode # RZ always truncates + short rnd_mnus - tbl_mode + short rnd_plus - tbl_mode + +################################################################# +# ROUND PLUS INFINITY # +# # +# If sign of fp number = 0 (positive), then add 1 to l. # +################################################################# +rnd_plus: + tst.b FTEMP_SGN(%a0) # check for sign + bmi.w truncate # if positive then truncate + + mov.l &0xffffffff, %d0 # force g,r,s to be all f's + swap %d1 # set up d1 for round prec. + + cmpi.b %d1, &s_mode # is prec = sgl? + beq.w add_sgl # yes + bgt.w add_dbl # no; it's dbl + bra.w add_ext # no; it's ext + +################################################################# +# ROUND MINUS INFINITY # +# # +# If sign of fp number = 1 (negative), then add 1 to l. # +################################################################# +rnd_mnus: + tst.b FTEMP_SGN(%a0) # check for sign + bpl.w truncate # if negative then truncate + + mov.l &0xffffffff, %d0 # force g,r,s to be all f's + swap %d1 # set up d1 for round prec. + + cmpi.b %d1, &s_mode # is prec = sgl? + beq.w add_sgl # yes + bgt.w add_dbl # no; it's dbl + bra.w add_ext # no; it's ext + +################################################################# +# ROUND NEAREST # +# # +# If (g=1), then add 1 to l and if (r=s=0), then clear l # +# Note that this will round to even in case of a tie. # +################################################################# +rnd_near: + asl.l &0x1, %d0 # shift g-bit to c-bit + bcc.w truncate # if (g=1) then + + swap %d1 # set up d1 for round prec. + + cmpi.b %d1, &s_mode # is prec = sgl? + beq.w add_sgl # yes + bgt.w add_dbl # no; it's dbl + bra.w add_ext # no; it's ext + +# *** LOCAL EQUATES *** +set ad_1_sgl, 0x00000100 # constant to add 1 to l-bit in sgl prec +set ad_1_dbl, 0x00000800 # constant to add 1 to l-bit in dbl prec + +######################### +# ADD SINGLE # +######################### +add_sgl: + add.l &ad_1_sgl, FTEMP_HI(%a0) + bcc.b scc_clr # no mantissa overflow + roxr.w FTEMP_HI(%a0) # shift v-bit back in + roxr.w FTEMP_HI+2(%a0) # shift v-bit back in + add.w &0x1, FTEMP_EX(%a0) # and incr exponent +scc_clr: + tst.l %d0 # test for rs = 0 + bne.b sgl_done + and.w &0xfe00, FTEMP_HI+2(%a0) # clear the l-bit +sgl_done: + and.l &0xffffff00, FTEMP_HI(%a0) # truncate bits beyond sgl limit + clr.l FTEMP_LO(%a0) # clear d2 + rts + +######################### +# ADD EXTENDED # +######################### +add_ext: + addq.l &1,FTEMP_LO(%a0) # add 1 to l-bit + bcc.b xcc_clr # test for carry out + addq.l &1,FTEMP_HI(%a0) # propagate carry + bcc.b xcc_clr + roxr.w FTEMP_HI(%a0) # mant is 0 so restore v-bit + roxr.w FTEMP_HI+2(%a0) # mant is 0 so restore v-bit + roxr.w FTEMP_LO(%a0) + roxr.w FTEMP_LO+2(%a0) + add.w &0x1,FTEMP_EX(%a0) # and inc exp +xcc_clr: + tst.l %d0 # test rs = 0 + bne.b add_ext_done + and.b &0xfe,FTEMP_LO+3(%a0) # clear the l bit +add_ext_done: + rts + +######################### +# ADD DOUBLE # +######################### +add_dbl: + add.l &ad_1_dbl, FTEMP_LO(%a0) # add 1 to lsb + bcc.b dcc_clr # no carry + addq.l &0x1, FTEMP_HI(%a0) # propagate carry + bcc.b dcc_clr # no carry + + roxr.w FTEMP_HI(%a0) # mant is 0 so restore v-bit + roxr.w FTEMP_HI+2(%a0) # mant is 0 so restore v-bit + roxr.w FTEMP_LO(%a0) + roxr.w FTEMP_LO+2(%a0) + addq.w &0x1, FTEMP_EX(%a0) # incr exponent +dcc_clr: + tst.l %d0 # test for rs = 0 + bne.b dbl_done + and.w &0xf000, FTEMP_LO+2(%a0) # clear the l-bit + +dbl_done: + and.l &0xfffff800,FTEMP_LO(%a0) # truncate bits beyond dbl limit + rts + +########################### +# Truncate all other bits # +########################### +truncate: + swap %d1 # select rnd prec + + cmpi.b %d1, &s_mode # is prec sgl? + beq.w sgl_done # yes + bgt.b dbl_done # no; it's dbl + rts # no; it's ext + + +# +# ext_grs(): extract guard, round and sticky bits according to +# rounding precision. +# +# INPUT +# d0 = extended precision g,r,s (in d0{31:29}) +# d1 = {PREC,ROUND} +# OUTPUT +# d0{31:29} = guard, round, sticky +# +# The ext_grs extract the guard/round/sticky bits according to the +# selected rounding precision. It is called by the round subroutine +# only. All registers except d0 are kept intact. d0 becomes an +# updated guard,round,sticky in d0{31:29} +# +# Notes: the ext_grs uses the round PREC, and therefore has to swap d1 +# prior to usage, and needs to restore d1 to original. this +# routine is tightly tied to the round routine and not meant to +# uphold standard subroutine calling practices. +# + +ext_grs: + swap %d1 # have d1.w point to round precision + tst.b %d1 # is rnd prec = extended? + bne.b ext_grs_not_ext # no; go handle sgl or dbl + +# +# %d0 actually already hold g,r,s since _round() had it before calling +# this function. so, as long as we don't disturb it, we are "returning" it. +# +ext_grs_ext: + swap %d1 # yes; return to correct positions + rts + +ext_grs_not_ext: + movm.l &0x3000, -(%sp) # make some temp registers {d2/d3} + + cmpi.b %d1, &s_mode # is rnd prec = sgl? + bne.b ext_grs_dbl # no; go handle dbl + +# +# sgl: +# 96 64 40 32 0 +# ----------------------------------------------------- +# | EXP |XXXXXXX| |xx | |grs| +# ----------------------------------------------------- +# <--(24)--->nn\ / +# ee --------------------- +# ww | +# v +# gr new sticky +# +ext_grs_sgl: + bfextu FTEMP_HI(%a0){&24:&2}, %d3 # sgl prec. g-r are 2 bits right + mov.l &30, %d2 # of the sgl prec. limits + lsl.l %d2, %d3 # shift g-r bits to MSB of d3 + mov.l FTEMP_HI(%a0), %d2 # get word 2 for s-bit test + and.l &0x0000003f, %d2 # s bit is the or of all other + bne.b ext_grs_st_stky # bits to the right of g-r + tst.l FTEMP_LO(%a0) # test lower mantissa + bne.b ext_grs_st_stky # if any are set, set sticky + tst.l %d0 # test original g,r,s + bne.b ext_grs_st_stky # if any are set, set sticky + bra.b ext_grs_end_sd # if words 3 and 4 are clr, exit + +# +# dbl: +# 96 64 32 11 0 +# ----------------------------------------------------- +# | EXP |XXXXXXX| | |xx |grs| +# ----------------------------------------------------- +# nn\ / +# ee ------- +# ww | +# v +# gr new sticky +# +ext_grs_dbl: + bfextu FTEMP_LO(%a0){&21:&2}, %d3 # dbl-prec. g-r are 2 bits right + mov.l &30, %d2 # of the dbl prec. limits + lsl.l %d2, %d3 # shift g-r bits to the MSB of d3 + mov.l FTEMP_LO(%a0), %d2 # get lower mantissa for s-bit test + and.l &0x000001ff, %d2 # s bit is the or-ing of all + bne.b ext_grs_st_stky # other bits to the right of g-r + tst.l %d0 # test word original g,r,s + bne.b ext_grs_st_stky # if any are set, set sticky + bra.b ext_grs_end_sd # if clear, exit + +ext_grs_st_stky: + bset &rnd_stky_bit, %d3 # set sticky bit +ext_grs_end_sd: + mov.l %d3, %d0 # return grs to d0 + + movm.l (%sp)+, &0xc # restore scratch registers {d2/d3} + + swap %d1 # restore d1 to original + rts + +######################################################################### +# norm(): normalize the mantissa of an extended precision input. the # +# input operand should not be normalized already. # +# # +# XDEF **************************************************************** # +# norm() # +# # +# XREF **************************************************************** # +# none # +# # +# INPUT *************************************************************** # +# a0 = pointer fp extended precision operand to normalize # +# # +# OUTPUT ************************************************************** # +# d0 = number of bit positions the mantissa was shifted # +# a0 = the input operand's mantissa is normalized; the exponent # +# is unchanged. # +# # +######################################################################### + global norm +norm: + mov.l %d2, -(%sp) # create some temp regs + mov.l %d3, -(%sp) + + mov.l FTEMP_HI(%a0), %d0 # load hi(mantissa) + mov.l FTEMP_LO(%a0), %d1 # load lo(mantissa) + + bfffo %d0{&0:&32}, %d2 # how many places to shift? + beq.b norm_lo # hi(man) is all zeroes! + +norm_hi: + lsl.l %d2, %d0 # left shift hi(man) + bfextu %d1{&0:%d2}, %d3 # extract lo bits + + or.l %d3, %d0 # create hi(man) + lsl.l %d2, %d1 # create lo(man) + + mov.l %d0, FTEMP_HI(%a0) # store new hi(man) + mov.l %d1, FTEMP_LO(%a0) # store new lo(man) + + mov.l %d2, %d0 # return shift amount + + mov.l (%sp)+, %d3 # restore temp regs + mov.l (%sp)+, %d2 + + rts + +norm_lo: + bfffo %d1{&0:&32}, %d2 # how many places to shift? + lsl.l %d2, %d1 # shift lo(man) + add.l &32, %d2 # add 32 to shft amount + + mov.l %d1, FTEMP_HI(%a0) # store hi(man) + clr.l FTEMP_LO(%a0) # lo(man) is now zero + + mov.l %d2, %d0 # return shift amount + + mov.l (%sp)+, %d3 # restore temp regs + mov.l (%sp)+, %d2 + + rts + +######################################################################### +# unnorm_fix(): - changes an UNNORM to one of NORM, DENORM, or ZERO # +# - returns corresponding optype tag # +# # +# XDEF **************************************************************** # +# unnorm_fix() # +# # +# XREF **************************************************************** # +# norm() - normalize the mantissa # +# # +# INPUT *************************************************************** # +# a0 = pointer to unnormalized extended precision number # +# # +# OUTPUT ************************************************************** # +# d0 = optype tag - is corrected to one of NORM, DENORM, or ZERO # +# a0 = input operand has been converted to a norm, denorm, or # +# zero; both the exponent and mantissa are changed. # +# # +######################################################################### + + global unnorm_fix +unnorm_fix: + bfffo FTEMP_HI(%a0){&0:&32}, %d0 # how many shifts are needed? + bne.b unnorm_shift # hi(man) is not all zeroes + +# +# hi(man) is all zeroes so see if any bits in lo(man) are set +# +unnorm_chk_lo: + bfffo FTEMP_LO(%a0){&0:&32}, %d0 # is operand really a zero? + beq.w unnorm_zero # yes + + add.w &32, %d0 # no; fix shift distance + +# +# d0 = # shifts needed for complete normalization +# +unnorm_shift: + clr.l %d1 # clear top word + mov.w FTEMP_EX(%a0), %d1 # extract exponent + and.w &0x7fff, %d1 # strip off sgn + + cmp.w %d0, %d1 # will denorm push exp < 0? + bgt.b unnorm_nrm_zero # yes; denorm only until exp = 0 + +# +# exponent would not go < 0. Therefore, number stays normalized +# + sub.w %d0, %d1 # shift exponent value + mov.w FTEMP_EX(%a0), %d0 # load old exponent + and.w &0x8000, %d0 # save old sign + or.w %d0, %d1 # {sgn,new exp} + mov.w %d1, FTEMP_EX(%a0) # insert new exponent + + bsr.l norm # normalize UNNORM + + mov.b &NORM, %d0 # return new optype tag + rts + +# +# exponent would go < 0, so only denormalize until exp = 0 +# +unnorm_nrm_zero: + cmp.b %d1, &32 # is exp <= 32? + bgt.b unnorm_nrm_zero_lrg # no; go handle large exponent + + bfextu FTEMP_HI(%a0){%d1:&32}, %d0 # extract new hi(man) + mov.l %d0, FTEMP_HI(%a0) # save new hi(man) + + mov.l FTEMP_LO(%a0), %d0 # fetch old lo(man) + lsl.l %d1, %d0 # extract new lo(man) + mov.l %d0, FTEMP_LO(%a0) # save new lo(man) + + and.w &0x8000, FTEMP_EX(%a0) # set exp = 0 + + mov.b &DENORM, %d0 # return new optype tag + rts + +# +# only mantissa bits set are in lo(man) +# +unnorm_nrm_zero_lrg: + sub.w &32, %d1 # adjust shft amt by 32 + + mov.l FTEMP_LO(%a0), %d0 # fetch old lo(man) + lsl.l %d1, %d0 # left shift lo(man) + + mov.l %d0, FTEMP_HI(%a0) # store new hi(man) + clr.l FTEMP_LO(%a0) # lo(man) = 0 + + and.w &0x8000, FTEMP_EX(%a0) # set exp = 0 + + mov.b &DENORM, %d0 # return new optype tag + rts + +# +# whole mantissa is zero so this UNNORM is actually a zero +# +unnorm_zero: + and.w &0x8000, FTEMP_EX(%a0) # force exponent to zero + + mov.b &ZERO, %d0 # fix optype tag + rts + +######################################################################### +# XDEF **************************************************************** # +# set_tag_x(): return the optype of the input ext fp number # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision operand # +# # +# OUTPUT ************************************************************** # +# d0 = value of type tag # +# one of: NORM, INF, QNAN, SNAN, DENORM, UNNORM, ZERO # +# # +# ALGORITHM *********************************************************** # +# Simply test the exponent, j-bit, and mantissa values to # +# determine the type of operand. # +# If it's an unnormalized zero, alter the operand and force it # +# to be a normal zero. # +# # +######################################################################### + + global set_tag_x +set_tag_x: + mov.w FTEMP_EX(%a0), %d0 # extract exponent + andi.w &0x7fff, %d0 # strip off sign + cmpi.w %d0, &0x7fff # is (EXP == MAX)? + beq.b inf_or_nan_x +not_inf_or_nan_x: + btst &0x7,FTEMP_HI(%a0) + beq.b not_norm_x +is_norm_x: + mov.b &NORM, %d0 + rts +not_norm_x: + tst.w %d0 # is exponent = 0? + bne.b is_unnorm_x +not_unnorm_x: + tst.l FTEMP_HI(%a0) + bne.b is_denorm_x + tst.l FTEMP_LO(%a0) + bne.b is_denorm_x +is_zero_x: + mov.b &ZERO, %d0 + rts +is_denorm_x: + mov.b &DENORM, %d0 + rts +# must distinguish now "Unnormalized zeroes" which we +# must convert to zero. +is_unnorm_x: + tst.l FTEMP_HI(%a0) + bne.b is_unnorm_reg_x + tst.l FTEMP_LO(%a0) + bne.b is_unnorm_reg_x +# it's an "unnormalized zero". let's convert it to an actual zero... + andi.w &0x8000,FTEMP_EX(%a0) # clear exponent + mov.b &ZERO, %d0 + rts +is_unnorm_reg_x: + mov.b &UNNORM, %d0 + rts +inf_or_nan_x: + tst.l FTEMP_LO(%a0) + bne.b is_nan_x + mov.l FTEMP_HI(%a0), %d0 + and.l &0x7fffffff, %d0 # msb is a don't care! + bne.b is_nan_x +is_inf_x: + mov.b &INF, %d0 + rts +is_nan_x: + btst &0x6, FTEMP_HI(%a0) + beq.b is_snan_x + mov.b &QNAN, %d0 + rts +is_snan_x: + mov.b &SNAN, %d0 + rts + +######################################################################### +# XDEF **************************************************************** # +# set_tag_d(): return the optype of the input dbl fp number # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# a0 = points to double precision operand # +# # +# OUTPUT ************************************************************** # +# d0 = value of type tag # +# one of: NORM, INF, QNAN, SNAN, DENORM, ZERO # +# # +# ALGORITHM *********************************************************** # +# Simply test the exponent, j-bit, and mantissa values to # +# determine the type of operand. # +# # +######################################################################### + + global set_tag_d +set_tag_d: + mov.l FTEMP(%a0), %d0 + mov.l %d0, %d1 + + andi.l &0x7ff00000, %d0 + beq.b zero_or_denorm_d + + cmpi.l %d0, &0x7ff00000 + beq.b inf_or_nan_d + +is_norm_d: + mov.b &NORM, %d0 + rts +zero_or_denorm_d: + and.l &0x000fffff, %d1 + bne is_denorm_d + tst.l 4+FTEMP(%a0) + bne is_denorm_d +is_zero_d: + mov.b &ZERO, %d0 + rts +is_denorm_d: + mov.b &DENORM, %d0 + rts +inf_or_nan_d: + and.l &0x000fffff, %d1 + bne is_nan_d + tst.l 4+FTEMP(%a0) + bne is_nan_d +is_inf_d: + mov.b &INF, %d0 + rts +is_nan_d: + btst &19, %d1 + bne is_qnan_d +is_snan_d: + mov.b &SNAN, %d0 + rts +is_qnan_d: + mov.b &QNAN, %d0 + rts + +######################################################################### +# XDEF **************************************************************** # +# set_tag_s(): return the optype of the input sgl fp number # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# a0 = pointer to single precision operand # +# # +# OUTPUT ************************************************************** # +# d0 = value of type tag # +# one of: NORM, INF, QNAN, SNAN, DENORM, ZERO # +# # +# ALGORITHM *********************************************************** # +# Simply test the exponent, j-bit, and mantissa values to # +# determine the type of operand. # +# # +######################################################################### + + global set_tag_s +set_tag_s: + mov.l FTEMP(%a0), %d0 + mov.l %d0, %d1 + + andi.l &0x7f800000, %d0 + beq.b zero_or_denorm_s + + cmpi.l %d0, &0x7f800000 + beq.b inf_or_nan_s + +is_norm_s: + mov.b &NORM, %d0 + rts +zero_or_denorm_s: + and.l &0x007fffff, %d1 + bne is_denorm_s +is_zero_s: + mov.b &ZERO, %d0 + rts +is_denorm_s: + mov.b &DENORM, %d0 + rts +inf_or_nan_s: + and.l &0x007fffff, %d1 + bne is_nan_s +is_inf_s: + mov.b &INF, %d0 + rts +is_nan_s: + btst &22, %d1 + bne is_qnan_s +is_snan_s: + mov.b &SNAN, %d0 + rts +is_qnan_s: + mov.b &QNAN, %d0 + rts + +######################################################################### +# XDEF **************************************************************** # +# unf_res(): routine to produce default underflow result of a # +# scaled extended precision number; this is used by # +# fadd/fdiv/fmul/etc. emulation routines. # +# unf_res4(): same as above but for fsglmul/fsgldiv which use # +# single round prec and extended prec mode. # +# # +# XREF **************************************************************** # +# _denorm() - denormalize according to scale factor # +# _round() - round denormalized number according to rnd prec # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precison operand # +# d0 = scale factor # +# d1 = rounding precision/mode # +# # +# OUTPUT ************************************************************** # +# a0 = pointer to default underflow result in extended precision # +# d0.b = result FPSR_cc which caller may or may not want to save # +# # +# ALGORITHM *********************************************************** # +# Convert the input operand to "internal format" which means the # +# exponent is extended to 16 bits and the sign is stored in the unused # +# portion of the extended precison operand. Denormalize the number # +# according to the scale factor passed in d0. Then, round the # +# denormalized result. # +# Set the FPSR_exc bits as appropriate but return the cc bits in # +# d0 in case the caller doesn't want to save them (as is the case for # +# fmove out). # +# unf_res4() for fsglmul/fsgldiv forces the denorm to extended # +# precision and the rounding mode to single. # +# # +######################################################################### + global unf_res +unf_res: + mov.l %d1, -(%sp) # save rnd prec,mode on stack + + btst &0x7, FTEMP_EX(%a0) # make "internal" format + sne FTEMP_SGN(%a0) + + mov.w FTEMP_EX(%a0), %d1 # extract exponent + and.w &0x7fff, %d1 + sub.w %d0, %d1 + mov.w %d1, FTEMP_EX(%a0) # insert 16 bit exponent + + mov.l %a0, -(%sp) # save operand ptr during calls + + mov.l 0x4(%sp),%d0 # pass rnd prec. + andi.w &0x00c0,%d0 + lsr.w &0x4,%d0 + bsr.l _denorm # denorm result + + mov.l (%sp),%a0 + mov.w 0x6(%sp),%d1 # load prec:mode into %d1 + andi.w &0xc0,%d1 # extract rnd prec + lsr.w &0x4,%d1 + swap %d1 + mov.w 0x6(%sp),%d1 + andi.w &0x30,%d1 + lsr.w &0x4,%d1 + bsr.l _round # round the denorm + + mov.l (%sp)+, %a0 + +# result is now rounded properly. convert back to normal format + bclr &0x7, FTEMP_EX(%a0) # clear sgn first; may have residue + tst.b FTEMP_SGN(%a0) # is "internal result" sign set? + beq.b unf_res_chkifzero # no; result is positive + bset &0x7, FTEMP_EX(%a0) # set result sgn + clr.b FTEMP_SGN(%a0) # clear temp sign + +# the number may have become zero after rounding. set ccodes accordingly. +unf_res_chkifzero: + clr.l %d0 + tst.l FTEMP_HI(%a0) # is value now a zero? + bne.b unf_res_cont # no + tst.l FTEMP_LO(%a0) + bne.b unf_res_cont # no +# bset &z_bit, FPSR_CC(%a6) # yes; set zero ccode bit + bset &z_bit, %d0 # yes; set zero ccode bit + +unf_res_cont: + +# +# can inex1 also be set along with unfl and inex2??? +# +# we know that underflow has occurred. aunfl should be set if INEX2 is also set. +# + btst &inex2_bit, FPSR_EXCEPT(%a6) # is INEX2 set? + beq.b unf_res_end # no + bset &aunfl_bit, FPSR_AEXCEPT(%a6) # yes; set aunfl + +unf_res_end: + add.l &0x4, %sp # clear stack + rts + +# unf_res() for fsglmul() and fsgldiv(). + global unf_res4 +unf_res4: + mov.l %d1,-(%sp) # save rnd prec,mode on stack + + btst &0x7,FTEMP_EX(%a0) # make "internal" format + sne FTEMP_SGN(%a0) + + mov.w FTEMP_EX(%a0),%d1 # extract exponent + and.w &0x7fff,%d1 + sub.w %d0,%d1 + mov.w %d1,FTEMP_EX(%a0) # insert 16 bit exponent + + mov.l %a0,-(%sp) # save operand ptr during calls + + clr.l %d0 # force rnd prec = ext + bsr.l _denorm # denorm result + + mov.l (%sp),%a0 + mov.w &s_mode,%d1 # force rnd prec = sgl + swap %d1 + mov.w 0x6(%sp),%d1 # load rnd mode + andi.w &0x30,%d1 # extract rnd prec + lsr.w &0x4,%d1 + bsr.l _round # round the denorm + + mov.l (%sp)+,%a0 + +# result is now rounded properly. convert back to normal format + bclr &0x7,FTEMP_EX(%a0) # clear sgn first; may have residue + tst.b FTEMP_SGN(%a0) # is "internal result" sign set? + beq.b unf_res4_chkifzero # no; result is positive + bset &0x7,FTEMP_EX(%a0) # set result sgn + clr.b FTEMP_SGN(%a0) # clear temp sign + +# the number may have become zero after rounding. set ccodes accordingly. +unf_res4_chkifzero: + clr.l %d0 + tst.l FTEMP_HI(%a0) # is value now a zero? + bne.b unf_res4_cont # no + tst.l FTEMP_LO(%a0) + bne.b unf_res4_cont # no +# bset &z_bit,FPSR_CC(%a6) # yes; set zero ccode bit + bset &z_bit,%d0 # yes; set zero ccode bit + +unf_res4_cont: + +# +# can inex1 also be set along with unfl and inex2??? +# +# we know that underflow has occurred. aunfl should be set if INEX2 is also set. +# + btst &inex2_bit,FPSR_EXCEPT(%a6) # is INEX2 set? + beq.b unf_res4_end # no + bset &aunfl_bit,FPSR_AEXCEPT(%a6) # yes; set aunfl + +unf_res4_end: + add.l &0x4,%sp # clear stack + rts + +######################################################################### +# XDEF **************************************************************** # +# ovf_res(): routine to produce the default overflow result of # +# an overflowing number. # +# ovf_res2(): same as above but the rnd mode/prec are passed # +# differently. # +# # +# XREF **************************************************************** # +# none # +# # +# INPUT *************************************************************** # +# d1.b = '-1' => (-); '0' => (+) # +# ovf_res(): # +# d0 = rnd mode/prec # +# ovf_res2(): # +# hi(d0) = rnd prec # +# lo(d0) = rnd mode # +# # +# OUTPUT ************************************************************** # +# a0 = points to extended precision result # +# d0.b = condition code bits # +# # +# ALGORITHM *********************************************************** # +# The default overflow result can be determined by the sign of # +# the result and the rounding mode/prec in effect. These bits are # +# concatenated together to create an index into the default result # +# table. A pointer to the correct result is returned in a0. The # +# resulting condition codes are returned in d0 in case the caller # +# doesn't want FPSR_cc altered (as is the case for fmove out). # +# # +######################################################################### + + global ovf_res +ovf_res: + andi.w &0x10,%d1 # keep result sign + lsr.b &0x4,%d0 # shift prec/mode + or.b %d0,%d1 # concat the two + mov.w %d1,%d0 # make a copy + lsl.b &0x1,%d1 # multiply d1 by 2 + bra.b ovf_res_load + + global ovf_res2 +ovf_res2: + and.w &0x10, %d1 # keep result sign + or.b %d0, %d1 # insert rnd mode + swap %d0 + or.b %d0, %d1 # insert rnd prec + mov.w %d1, %d0 # make a copy + lsl.b &0x1, %d1 # shift left by 1 + +# +# use the rounding mode, precision, and result sign as in index into the +# two tables below to fetch the default result and the result ccodes. +# +ovf_res_load: + mov.b (tbl_ovfl_cc.b,%pc,%d0.w*1), %d0 # fetch result ccodes + lea (tbl_ovfl_result.b,%pc,%d1.w*8), %a0 # return result ptr + + rts + +tbl_ovfl_cc: + byte 0x2, 0x0, 0x0, 0x2 + byte 0x2, 0x0, 0x0, 0x2 + byte 0x2, 0x0, 0x0, 0x2 + byte 0x0, 0x0, 0x0, 0x0 + byte 0x2+0x8, 0x8, 0x2+0x8, 0x8 + byte 0x2+0x8, 0x8, 0x2+0x8, 0x8 + byte 0x2+0x8, 0x8, 0x2+0x8, 0x8 + +tbl_ovfl_result: + long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RN + long 0x7ffe0000,0xffffffff,0xffffffff,0x00000000 # +EXT; RZ + long 0x7ffe0000,0xffffffff,0xffffffff,0x00000000 # +EXT; RM + long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RP + + long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RN + long 0x407e0000,0xffffff00,0x00000000,0x00000000 # +SGL; RZ + long 0x407e0000,0xffffff00,0x00000000,0x00000000 # +SGL; RM + long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RP + + long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RN + long 0x43fe0000,0xffffffff,0xfffff800,0x00000000 # +DBL; RZ + long 0x43fe0000,0xffffffff,0xfffff800,0x00000000 # +DBL; RM + long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RP + + long 0x00000000,0x00000000,0x00000000,0x00000000 + long 0x00000000,0x00000000,0x00000000,0x00000000 + long 0x00000000,0x00000000,0x00000000,0x00000000 + long 0x00000000,0x00000000,0x00000000,0x00000000 + + long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RN + long 0xfffe0000,0xffffffff,0xffffffff,0x00000000 # -EXT; RZ + long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RM + long 0xfffe0000,0xffffffff,0xffffffff,0x00000000 # -EXT; RP + + long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RN + long 0xc07e0000,0xffffff00,0x00000000,0x00000000 # -SGL; RZ + long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RM + long 0xc07e0000,0xffffff00,0x00000000,0x00000000 # -SGL; RP + + long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RN + long 0xc3fe0000,0xffffffff,0xfffff800,0x00000000 # -DBL; RZ + long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RM + long 0xc3fe0000,0xffffffff,0xfffff800,0x00000000 # -DBL; RP + +######################################################################### +# XDEF **************************************************************** # +# fout(): move from fp register to memory or data register # +# # +# XREF **************************************************************** # +# _round() - needed to create EXOP for sgl/dbl precision # +# norm() - needed to create EXOP for extended precision # +# ovf_res() - create default overflow result for sgl/dbl precision# +# unf_res() - create default underflow result for sgl/dbl prec. # +# dst_dbl() - create rounded dbl precision result. # +# dst_sgl() - create rounded sgl precision result. # +# fetch_dreg() - fetch dynamic k-factor reg for packed. # +# bindec() - convert FP binary number to packed number. # +# _mem_write() - write data to memory. # +# _mem_write2() - write data to memory unless supv mode -(a7) exc.# +# _dmem_write_{byte,word,long}() - write data to memory. # +# store_dreg_{b,w,l}() - store data to data register file. # +# facc_out_{b,w,l,d,x}() - data access error occurred. # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# d0 = round prec,mode # +# # +# OUTPUT ************************************************************** # +# fp0 : intermediate underflow or overflow result if # +# OVFL/UNFL occurred for a sgl or dbl operand # +# # +# ALGORITHM *********************************************************** # +# This routine is accessed by many handlers that need to do an # +# opclass three move of an operand out to memory. # +# Decode an fmove out (opclass 3) instruction to determine if # +# it's b,w,l,s,d,x, or p in size. b,w,l can be stored to either a data # +# register or memory. The algorithm uses a standard "fmove" to create # +# the rounded result. Also, since exceptions are disabled, this also # +# create the correct OPERR default result if appropriate. # +# For sgl or dbl precision, overflow or underflow can occur. If # +# either occurs and is enabled, the EXOP. # +# For extended precision, the stacked <ea> must be fixed along # +# w/ the address index register as appropriate w/ _calc_ea_fout(). If # +# the source is a denorm and if underflow is enabled, an EXOP must be # +# created. # +# For packed, the k-factor must be fetched from the instruction # +# word or a data register. The <ea> must be fixed as w/ extended # +# precision. Then, bindec() is called to create the appropriate # +# packed result. # +# If at any time an access error is flagged by one of the move- # +# to-memory routines, then a special exit must be made so that the # +# access error can be handled properly. # +# # +######################################################################### + + global fout +fout: + bfextu EXC_CMDREG(%a6){&3:&3},%d1 # extract dst fmt + mov.w (tbl_fout.b,%pc,%d1.w*2),%a1 # use as index + jmp (tbl_fout.b,%pc,%a1) # jump to routine + + swbeg &0x8 +tbl_fout: + short fout_long - tbl_fout + short fout_sgl - tbl_fout + short fout_ext - tbl_fout + short fout_pack - tbl_fout + short fout_word - tbl_fout + short fout_dbl - tbl_fout + short fout_byte - tbl_fout + short fout_pack - tbl_fout + +################################################################# +# fmove.b out ################################################### +################################################################# + +# Only "Unimplemented Data Type" exceptions enter here. The operand +# is either a DENORM or a NORM. +fout_byte: + tst.b STAG(%a6) # is operand normalized? + bne.b fout_byte_denorm # no + + fmovm.x SRC(%a0),&0x80 # load value + +fout_byte_norm: + fmov.l %d0,%fpcr # insert rnd prec,mode + + fmov.b %fp0,%d0 # exec move out w/ correct rnd mode + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # fetch FPSR + or.w %d1,2+USER_FPSR(%a6) # save new exc,accrued bits + + mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode + andi.b &0x38,%d1 # is mode == 0? (Dreg dst) + beq.b fout_byte_dn # must save to integer regfile + + mov.l EXC_EA(%a6),%a0 # stacked <ea> is correct + bsr.l _dmem_write_byte # write byte + + tst.l %d1 # did dstore fail? + bne.l facc_out_b # yes + + rts + +fout_byte_dn: + mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn + andi.w &0x7,%d1 + bsr.l store_dreg_b + rts + +fout_byte_denorm: + mov.l SRC_EX(%a0),%d1 + andi.l &0x80000000,%d1 # keep DENORM sign + ori.l &0x00800000,%d1 # make smallest sgl + fmov.s %d1,%fp0 + bra.b fout_byte_norm + +################################################################# +# fmove.w out ################################################### +################################################################# + +# Only "Unimplemented Data Type" exceptions enter here. The operand +# is either a DENORM or a NORM. +fout_word: + tst.b STAG(%a6) # is operand normalized? + bne.b fout_word_denorm # no + + fmovm.x SRC(%a0),&0x80 # load value + +fout_word_norm: + fmov.l %d0,%fpcr # insert rnd prec:mode + + fmov.w %fp0,%d0 # exec move out w/ correct rnd mode + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # fetch FPSR + or.w %d1,2+USER_FPSR(%a6) # save new exc,accrued bits + + mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode + andi.b &0x38,%d1 # is mode == 0? (Dreg dst) + beq.b fout_word_dn # must save to integer regfile + + mov.l EXC_EA(%a6),%a0 # stacked <ea> is correct + bsr.l _dmem_write_word # write word + + tst.l %d1 # did dstore fail? + bne.l facc_out_w # yes + + rts + +fout_word_dn: + mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn + andi.w &0x7,%d1 + bsr.l store_dreg_w + rts + +fout_word_denorm: + mov.l SRC_EX(%a0),%d1 + andi.l &0x80000000,%d1 # keep DENORM sign + ori.l &0x00800000,%d1 # make smallest sgl + fmov.s %d1,%fp0 + bra.b fout_word_norm + +################################################################# +# fmove.l out ################################################### +################################################################# + +# Only "Unimplemented Data Type" exceptions enter here. The operand +# is either a DENORM or a NORM. +fout_long: + tst.b STAG(%a6) # is operand normalized? + bne.b fout_long_denorm # no + + fmovm.x SRC(%a0),&0x80 # load value + +fout_long_norm: + fmov.l %d0,%fpcr # insert rnd prec:mode + + fmov.l %fp0,%d0 # exec move out w/ correct rnd mode + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # fetch FPSR + or.w %d1,2+USER_FPSR(%a6) # save new exc,accrued bits + +fout_long_write: + mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode + andi.b &0x38,%d1 # is mode == 0? (Dreg dst) + beq.b fout_long_dn # must save to integer regfile + + mov.l EXC_EA(%a6),%a0 # stacked <ea> is correct + bsr.l _dmem_write_long # write long + + tst.l %d1 # did dstore fail? + bne.l facc_out_l # yes + + rts + +fout_long_dn: + mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn + andi.w &0x7,%d1 + bsr.l store_dreg_l + rts + +fout_long_denorm: + mov.l SRC_EX(%a0),%d1 + andi.l &0x80000000,%d1 # keep DENORM sign + ori.l &0x00800000,%d1 # make smallest sgl + fmov.s %d1,%fp0 + bra.b fout_long_norm + +################################################################# +# fmove.x out ################################################### +################################################################# + +# Only "Unimplemented Data Type" exceptions enter here. The operand +# is either a DENORM or a NORM. +# The DENORM causes an Underflow exception. +fout_ext: + +# we copy the extended precision result to FP_SCR0 so that the reserved +# 16-bit field gets zeroed. we do this since we promise not to disturb +# what's at SRC(a0). + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + clr.w 2+FP_SCR0_EX(%a6) # clear reserved field + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + + fmovm.x SRC(%a0),&0x80 # return result + + bsr.l _calc_ea_fout # fix stacked <ea> + + mov.l %a0,%a1 # pass: dst addr + lea FP_SCR0(%a6),%a0 # pass: src addr + mov.l &0xc,%d0 # pass: opsize is 12 bytes + +# we must not yet write the extended precision data to the stack +# in the pre-decrement case from supervisor mode or else we'll corrupt +# the stack frame. so, leave it in FP_SRC for now and deal with it later... + cmpi.b SPCOND_FLG(%a6),&mda7_flg + beq.b fout_ext_a7 + + bsr.l _dmem_write # write ext prec number to memory + + tst.l %d1 # did dstore fail? + bne.w fout_ext_err # yes + + tst.b STAG(%a6) # is operand normalized? + bne.b fout_ext_denorm # no + rts + +# the number is a DENORM. must set the underflow exception bit +fout_ext_denorm: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set underflow exc bit + + mov.b FPCR_ENABLE(%a6),%d0 + andi.b &0x0a,%d0 # is UNFL or INEX enabled? + bne.b fout_ext_exc # yes + rts + +# we don't want to do the write if the exception occurred in supervisor mode +# so _mem_write2() handles this for us. +fout_ext_a7: + bsr.l _mem_write2 # write ext prec number to memory + + tst.l %d1 # did dstore fail? + bne.w fout_ext_err # yes + + tst.b STAG(%a6) # is operand normalized? + bne.b fout_ext_denorm # no + rts + +fout_ext_exc: + lea FP_SCR0(%a6),%a0 + bsr.l norm # normalize the mantissa + neg.w %d0 # new exp = -(shft amt) + andi.w &0x7fff,%d0 + andi.w &0x8000,FP_SCR0_EX(%a6) # keep only old sign + or.w %d0,FP_SCR0_EX(%a6) # insert new exponent + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + rts + +fout_ext_err: + mov.l EXC_A6(%a6),(%a6) # fix stacked a6 + bra.l facc_out_x + +######################################################################### +# fmove.s out ########################################################### +######################################################################### +fout_sgl: + andi.b &0x30,%d0 # clear rnd prec + ori.b &s_mode*0x10,%d0 # insert sgl prec + mov.l %d0,L_SCR3(%a6) # save rnd prec,mode on stack + +# +# operand is a normalized number. first, we check to see if the move out +# would cause either an underflow or overflow. these cases are handled +# separately. otherwise, set the FPCR to the proper rounding mode and +# execute the move. +# + mov.w SRC_EX(%a0),%d0 # extract exponent + andi.w &0x7fff,%d0 # strip sign + + cmpi.w %d0,&SGL_HI # will operand overflow? + bgt.w fout_sgl_ovfl # yes; go handle OVFL + beq.w fout_sgl_may_ovfl # maybe; go handle possible OVFL + cmpi.w %d0,&SGL_LO # will operand underflow? + blt.w fout_sgl_unfl # yes; go handle underflow + +# +# NORMs(in range) can be stored out by a simple "fmov.s" +# Unnormalized inputs can come through this point. +# +fout_sgl_exg: + fmovm.x SRC(%a0),&0x80 # fetch fop from stack + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fmov.s %fp0,%d0 # store does convert and round + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # save FPSR + + or.w %d1,2+USER_FPSR(%a6) # set possible inex2/ainex + +fout_sgl_exg_write: + mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode + andi.b &0x38,%d1 # is mode == 0? (Dreg dst) + beq.b fout_sgl_exg_write_dn # must save to integer regfile + + mov.l EXC_EA(%a6),%a0 # stacked <ea> is correct + bsr.l _dmem_write_long # write long + + tst.l %d1 # did dstore fail? + bne.l facc_out_l # yes + + rts + +fout_sgl_exg_write_dn: + mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn + andi.w &0x7,%d1 + bsr.l store_dreg_l + rts + +# +# here, we know that the operand would UNFL if moved out to single prec, +# so, denorm and round and then use generic store single routine to +# write the value to memory. +# +fout_sgl_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set UNFL + + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + mov.l %a0,-(%sp) + + clr.l %d0 # pass: S.F. = 0 + + cmpi.b STAG(%a6),&DENORM # fetch src optype tag + bne.b fout_sgl_unfl_cont # let DENORMs fall through + + lea FP_SCR0(%a6),%a0 + bsr.l norm # normalize the DENORM + +fout_sgl_unfl_cont: + lea FP_SCR0(%a6),%a0 # pass: ptr to operand + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calc default underflow result + + lea FP_SCR0(%a6),%a0 # pass: ptr to fop + bsr.l dst_sgl # convert to single prec + + mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode + andi.b &0x38,%d1 # is mode == 0? (Dreg dst) + beq.b fout_sgl_unfl_dn # must save to integer regfile + + mov.l EXC_EA(%a6),%a0 # stacked <ea> is correct + bsr.l _dmem_write_long # write long + + tst.l %d1 # did dstore fail? + bne.l facc_out_l # yes + + bra.b fout_sgl_unfl_chkexc + +fout_sgl_unfl_dn: + mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn + andi.w &0x7,%d1 + bsr.l store_dreg_l + +fout_sgl_unfl_chkexc: + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0a,%d1 # is UNFL or INEX enabled? + bne.w fout_sd_exc_unfl # yes + addq.l &0x4,%sp + rts + +# +# it's definitely an overflow so call ovf_res to get the correct answer +# +fout_sgl_ovfl: + tst.b 3+SRC_HI(%a0) # is result inexact? + bne.b fout_sgl_ovfl_inex2 + tst.l SRC_LO(%a0) # is result inexact? + bne.b fout_sgl_ovfl_inex2 + ori.w &ovfl_inx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex + bra.b fout_sgl_ovfl_cont +fout_sgl_ovfl_inex2: + ori.w &ovfinx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex/inex2 + +fout_sgl_ovfl_cont: + mov.l %a0,-(%sp) + +# call ovf_res() w/ sgl prec and the correct rnd mode to create the default +# overflow result. DON'T save the returned ccodes from ovf_res() since +# fmove out doesn't alter them. + tst.b SRC_EX(%a0) # is operand negative? + smi %d1 # set if so + mov.l L_SCR3(%a6),%d0 # pass: sgl prec,rnd mode + bsr.l ovf_res # calc OVFL result + fmovm.x (%a0),&0x80 # load default overflow result + fmov.s %fp0,%d0 # store to single + + mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode + andi.b &0x38,%d1 # is mode == 0? (Dreg dst) + beq.b fout_sgl_ovfl_dn # must save to integer regfile + + mov.l EXC_EA(%a6),%a0 # stacked <ea> is correct + bsr.l _dmem_write_long # write long + + tst.l %d1 # did dstore fail? + bne.l facc_out_l # yes + + bra.b fout_sgl_ovfl_chkexc + +fout_sgl_ovfl_dn: + mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn + andi.w &0x7,%d1 + bsr.l store_dreg_l + +fout_sgl_ovfl_chkexc: + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0a,%d1 # is UNFL or INEX enabled? + bne.w fout_sd_exc_ovfl # yes + addq.l &0x4,%sp + rts + +# +# move out MAY overflow: +# (1) force the exp to 0x3fff +# (2) do a move w/ appropriate rnd mode +# (3) if exp still equals zero, then insert original exponent +# for the correct result. +# if exp now equals one, then it overflowed so call ovf_res. +# +fout_sgl_may_ovfl: + mov.w SRC_EX(%a0),%d1 # fetch current sign + andi.w &0x8000,%d1 # keep it,clear exp + ori.w &0x3fff,%d1 # insert exp = 0 + mov.w %d1,FP_SCR0_EX(%a6) # insert scaled exp + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) # copy hi(man) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) # copy lo(man) + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fmov.x FP_SCR0(%a6),%fp0 # force fop to be rounded + fmov.l &0x0,%fpcr # clear FPCR + + fabs.x %fp0 # need absolute value + fcmp.b %fp0,&0x2 # did exponent increase? + fblt.w fout_sgl_exg # no; go finish NORM + bra.w fout_sgl_ovfl # yes; go handle overflow + +################ + +fout_sd_exc_unfl: + mov.l (%sp)+,%a0 + + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + + cmpi.b STAG(%a6),&DENORM # was src a DENORM? + bne.b fout_sd_exc_cont # no + + lea FP_SCR0(%a6),%a0 + bsr.l norm + neg.l %d0 + andi.w &0x7fff,%d0 + bfins %d0,FP_SCR0_EX(%a6){&1:&15} + bra.b fout_sd_exc_cont + +fout_sd_exc: +fout_sd_exc_ovfl: + mov.l (%sp)+,%a0 # restore a0 + + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + +fout_sd_exc_cont: + bclr &0x7,FP_SCR0_EX(%a6) # clear sign bit + sne.b 2+FP_SCR0_EX(%a6) # set internal sign bit + lea FP_SCR0(%a6),%a0 # pass: ptr to DENORM + + mov.b 3+L_SCR3(%a6),%d1 + lsr.b &0x4,%d1 + andi.w &0x0c,%d1 + swap %d1 + mov.b 3+L_SCR3(%a6),%d1 + lsr.b &0x4,%d1 + andi.w &0x03,%d1 + clr.l %d0 # pass: zero g,r,s + bsr.l _round # round the DENORM + + tst.b 2+FP_SCR0_EX(%a6) # is EXOP negative? + beq.b fout_sd_exc_done # no + bset &0x7,FP_SCR0_EX(%a6) # yes + +fout_sd_exc_done: + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + rts + +################################################################# +# fmove.d out ################################################### +################################################################# +fout_dbl: + andi.b &0x30,%d0 # clear rnd prec + ori.b &d_mode*0x10,%d0 # insert dbl prec + mov.l %d0,L_SCR3(%a6) # save rnd prec,mode on stack + +# +# operand is a normalized number. first, we check to see if the move out +# would cause either an underflow or overflow. these cases are handled +# separately. otherwise, set the FPCR to the proper rounding mode and +# execute the move. +# + mov.w SRC_EX(%a0),%d0 # extract exponent + andi.w &0x7fff,%d0 # strip sign + + cmpi.w %d0,&DBL_HI # will operand overflow? + bgt.w fout_dbl_ovfl # yes; go handle OVFL + beq.w fout_dbl_may_ovfl # maybe; go handle possible OVFL + cmpi.w %d0,&DBL_LO # will operand underflow? + blt.w fout_dbl_unfl # yes; go handle underflow + +# +# NORMs(in range) can be stored out by a simple "fmov.d" +# Unnormalized inputs can come through this point. +# +fout_dbl_exg: + fmovm.x SRC(%a0),&0x80 # fetch fop from stack + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fmov.d %fp0,L_SCR1(%a6) # store does convert and round + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d0 # save FPSR + + or.w %d0,2+USER_FPSR(%a6) # set possible inex2/ainex + + mov.l EXC_EA(%a6),%a1 # pass: dst addr + lea L_SCR1(%a6),%a0 # pass: src addr + movq.l &0x8,%d0 # pass: opsize is 8 bytes + bsr.l _dmem_write # store dbl fop to memory + + tst.l %d1 # did dstore fail? + bne.l facc_out_d # yes + + rts # no; so we're finished + +# +# here, we know that the operand would UNFL if moved out to double prec, +# so, denorm and round and then use generic store double routine to +# write the value to memory. +# +fout_dbl_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set UNFL + + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + mov.l %a0,-(%sp) + + clr.l %d0 # pass: S.F. = 0 + + cmpi.b STAG(%a6),&DENORM # fetch src optype tag + bne.b fout_dbl_unfl_cont # let DENORMs fall through + + lea FP_SCR0(%a6),%a0 + bsr.l norm # normalize the DENORM + +fout_dbl_unfl_cont: + lea FP_SCR0(%a6),%a0 # pass: ptr to operand + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calc default underflow result + + lea FP_SCR0(%a6),%a0 # pass: ptr to fop + bsr.l dst_dbl # convert to single prec + mov.l %d0,L_SCR1(%a6) + mov.l %d1,L_SCR2(%a6) + + mov.l EXC_EA(%a6),%a1 # pass: dst addr + lea L_SCR1(%a6),%a0 # pass: src addr + movq.l &0x8,%d0 # pass: opsize is 8 bytes + bsr.l _dmem_write # store dbl fop to memory + + tst.l %d1 # did dstore fail? + bne.l facc_out_d # yes + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0a,%d1 # is UNFL or INEX enabled? + bne.w fout_sd_exc_unfl # yes + addq.l &0x4,%sp + rts + +# +# it's definitely an overflow so call ovf_res to get the correct answer +# +fout_dbl_ovfl: + mov.w 2+SRC_LO(%a0),%d0 + andi.w &0x7ff,%d0 + bne.b fout_dbl_ovfl_inex2 + + ori.w &ovfl_inx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex + bra.b fout_dbl_ovfl_cont +fout_dbl_ovfl_inex2: + ori.w &ovfinx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex/inex2 + +fout_dbl_ovfl_cont: + mov.l %a0,-(%sp) + +# call ovf_res() w/ dbl prec and the correct rnd mode to create the default +# overflow result. DON'T save the returned ccodes from ovf_res() since +# fmove out doesn't alter them. + tst.b SRC_EX(%a0) # is operand negative? + smi %d1 # set if so + mov.l L_SCR3(%a6),%d0 # pass: dbl prec,rnd mode + bsr.l ovf_res # calc OVFL result + fmovm.x (%a0),&0x80 # load default overflow result + fmov.d %fp0,L_SCR1(%a6) # store to double + + mov.l EXC_EA(%a6),%a1 # pass: dst addr + lea L_SCR1(%a6),%a0 # pass: src addr + movq.l &0x8,%d0 # pass: opsize is 8 bytes + bsr.l _dmem_write # store dbl fop to memory + + tst.l %d1 # did dstore fail? + bne.l facc_out_d # yes + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0a,%d1 # is UNFL or INEX enabled? + bne.w fout_sd_exc_ovfl # yes + addq.l &0x4,%sp + rts + +# +# move out MAY overflow: +# (1) force the exp to 0x3fff +# (2) do a move w/ appropriate rnd mode +# (3) if exp still equals zero, then insert original exponent +# for the correct result. +# if exp now equals one, then it overflowed so call ovf_res. +# +fout_dbl_may_ovfl: + mov.w SRC_EX(%a0),%d1 # fetch current sign + andi.w &0x8000,%d1 # keep it,clear exp + ori.w &0x3fff,%d1 # insert exp = 0 + mov.w %d1,FP_SCR0_EX(%a6) # insert scaled exp + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) # copy hi(man) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) # copy lo(man) + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fmov.x FP_SCR0(%a6),%fp0 # force fop to be rounded + fmov.l &0x0,%fpcr # clear FPCR + + fabs.x %fp0 # need absolute value + fcmp.b %fp0,&0x2 # did exponent increase? + fblt.w fout_dbl_exg # no; go finish NORM + bra.w fout_dbl_ovfl # yes; go handle overflow + +######################################################################### +# XDEF **************************************************************** # +# dst_dbl(): create double precision value from extended prec. # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# a0 = pointer to source operand in extended precision # +# # +# OUTPUT ************************************************************** # +# d0 = hi(double precision result) # +# d1 = lo(double precision result) # +# # +# ALGORITHM *********************************************************** # +# # +# Changes extended precision to double precision. # +# Note: no attempt is made to round the extended value to double. # +# dbl_sign = ext_sign # +# dbl_exp = ext_exp - $3fff(ext bias) + $7ff(dbl bias) # +# get rid of ext integer bit # +# dbl_mant = ext_mant{62:12} # +# # +# --------------- --------------- --------------- # +# extended -> |s| exp | |1| ms mant | | ls mant | # +# --------------- --------------- --------------- # +# 95 64 63 62 32 31 11 0 # +# | | # +# | | # +# | | # +# v v # +# --------------- --------------- # +# double -> |s|exp| mant | | mant | # +# --------------- --------------- # +# 63 51 32 31 0 # +# # +######################################################################### + +dst_dbl: + clr.l %d0 # clear d0 + mov.w FTEMP_EX(%a0),%d0 # get exponent + subi.w &EXT_BIAS,%d0 # subtract extended precision bias + addi.w &DBL_BIAS,%d0 # add double precision bias + tst.b FTEMP_HI(%a0) # is number a denorm? + bmi.b dst_get_dupper # no + subq.w &0x1,%d0 # yes; denorm bias = DBL_BIAS - 1 +dst_get_dupper: + swap %d0 # d0 now in upper word + lsl.l &0x4,%d0 # d0 in proper place for dbl prec exp + tst.b FTEMP_EX(%a0) # test sign + bpl.b dst_get_dman # if positive, go process mantissa + bset &0x1f,%d0 # if negative, set sign +dst_get_dman: + mov.l FTEMP_HI(%a0),%d1 # get ms mantissa + bfextu %d1{&1:&20},%d1 # get upper 20 bits of ms + or.l %d1,%d0 # put these bits in ms word of double + mov.l %d0,L_SCR1(%a6) # put the new exp back on the stack + mov.l FTEMP_HI(%a0),%d1 # get ms mantissa + mov.l &21,%d0 # load shift count + lsl.l %d0,%d1 # put lower 11 bits in upper bits + mov.l %d1,L_SCR2(%a6) # build lower lword in memory + mov.l FTEMP_LO(%a0),%d1 # get ls mantissa + bfextu %d1{&0:&21},%d0 # get ls 21 bits of double + mov.l L_SCR2(%a6),%d1 + or.l %d0,%d1 # put them in double result + mov.l L_SCR1(%a6),%d0 + rts + +######################################################################### +# XDEF **************************************************************** # +# dst_sgl(): create single precision value from extended prec # +# # +# XREF **************************************************************** # +# # +# INPUT *************************************************************** # +# a0 = pointer to source operand in extended precision # +# # +# OUTPUT ************************************************************** # +# d0 = single precision result # +# # +# ALGORITHM *********************************************************** # +# # +# Changes extended precision to single precision. # +# sgl_sign = ext_sign # +# sgl_exp = ext_exp - $3fff(ext bias) + $7f(sgl bias) # +# get rid of ext integer bit # +# sgl_mant = ext_mant{62:12} # +# # +# --------------- --------------- --------------- # +# extended -> |s| exp | |1| ms mant | | ls mant | # +# --------------- --------------- --------------- # +# 95 64 63 62 40 32 31 12 0 # +# | | # +# | | # +# | | # +# v v # +# --------------- # +# single -> |s|exp| mant | # +# --------------- # +# 31 22 0 # +# # +######################################################################### + +dst_sgl: + clr.l %d0 + mov.w FTEMP_EX(%a0),%d0 # get exponent + subi.w &EXT_BIAS,%d0 # subtract extended precision bias + addi.w &SGL_BIAS,%d0 # add single precision bias + tst.b FTEMP_HI(%a0) # is number a denorm? + bmi.b dst_get_supper # no + subq.w &0x1,%d0 # yes; denorm bias = SGL_BIAS - 1 +dst_get_supper: + swap %d0 # put exp in upper word of d0 + lsl.l &0x7,%d0 # shift it into single exp bits + tst.b FTEMP_EX(%a0) # test sign + bpl.b dst_get_sman # if positive, continue + bset &0x1f,%d0 # if negative, put in sign first +dst_get_sman: + mov.l FTEMP_HI(%a0),%d1 # get ms mantissa + andi.l &0x7fffff00,%d1 # get upper 23 bits of ms + lsr.l &0x8,%d1 # and put them flush right + or.l %d1,%d0 # put these bits in ms word of single + rts + +############################################################################## +fout_pack: + bsr.l _calc_ea_fout # fetch the <ea> + mov.l %a0,-(%sp) + + mov.b STAG(%a6),%d0 # fetch input type + bne.w fout_pack_not_norm # input is not NORM + +fout_pack_norm: + btst &0x4,EXC_CMDREG(%a6) # static or dynamic? + beq.b fout_pack_s # static + +fout_pack_d: + mov.b 1+EXC_CMDREG(%a6),%d1 # fetch dynamic reg + lsr.b &0x4,%d1 + andi.w &0x7,%d1 + + bsr.l fetch_dreg # fetch Dn w/ k-factor + + bra.b fout_pack_type +fout_pack_s: + mov.b 1+EXC_CMDREG(%a6),%d0 # fetch static field + +fout_pack_type: + bfexts %d0{&25:&7},%d0 # extract k-factor + mov.l %d0,-(%sp) + + lea FP_SRC(%a6),%a0 # pass: ptr to input + +# bindec is currently scrambling FP_SRC for denorm inputs. +# we'll have to change this, but for now, tough luck!!! + bsr.l bindec # convert xprec to packed + +# andi.l &0xcfff000f,FP_SCR0(%a6) # clear unused fields + andi.l &0xcffff00f,FP_SCR0(%a6) # clear unused fields + + mov.l (%sp)+,%d0 + + tst.b 3+FP_SCR0_EX(%a6) + bne.b fout_pack_set + tst.l FP_SCR0_HI(%a6) + bne.b fout_pack_set + tst.l FP_SCR0_LO(%a6) + bne.b fout_pack_set + +# add the extra condition that only if the k-factor was zero, too, should +# we zero the exponent + tst.l %d0 + bne.b fout_pack_set +# "mantissa" is all zero which means that the answer is zero. but, the '040 +# algorithm allows the exponent to be non-zero. the 881/2 do not. Therefore, +# if the mantissa is zero, I will zero the exponent, too. +# the question now is whether the exponents sign bit is allowed to be non-zero +# for a zero, also... + andi.w &0xf000,FP_SCR0(%a6) + +fout_pack_set: + + lea FP_SCR0(%a6),%a0 # pass: src addr + +fout_pack_write: + mov.l (%sp)+,%a1 # pass: dst addr + mov.l &0xc,%d0 # pass: opsize is 12 bytes + + cmpi.b SPCOND_FLG(%a6),&mda7_flg + beq.b fout_pack_a7 + + bsr.l _dmem_write # write ext prec number to memory + + tst.l %d1 # did dstore fail? + bne.w fout_ext_err # yes + + rts + +# we don't want to do the write if the exception occurred in supervisor mode +# so _mem_write2() handles this for us. +fout_pack_a7: + bsr.l _mem_write2 # write ext prec number to memory + + tst.l %d1 # did dstore fail? + bne.w fout_ext_err # yes + + rts + +fout_pack_not_norm: + cmpi.b %d0,&DENORM # is it a DENORM? + beq.w fout_pack_norm # yes + lea FP_SRC(%a6),%a0 + clr.w 2+FP_SRC_EX(%a6) + cmpi.b %d0,&SNAN # is it an SNAN? + beq.b fout_pack_snan # yes + bra.b fout_pack_write # no + +fout_pack_snan: + ori.w &snaniop2_mask,FPSR_EXCEPT(%a6) # set SNAN/AIOP + bset &0x6,FP_SRC_HI(%a6) # set snan bit + bra.b fout_pack_write + +######################################################################### +# XDEF **************************************************************** # +# fmul(): emulates the fmul instruction # +# fsmul(): emulates the fsmul instruction # +# fdmul(): emulates the fdmul instruction # +# # +# XREF **************************************************************** # +# scale_to_zero_src() - scale src exponent to zero # +# scale_to_zero_dst() - scale dst exponent to zero # +# unf_res() - return default underflow result # +# ovf_res() - return default overflow result # +# res_qnan() - return QNAN result # +# res_snan() - return SNAN result # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# a1 = pointer to extended precision destination operand # +# d0 rnd prec,mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, infinities, and zeroes as special cases. Divide # +# norms/denorms into ext/sgl/dbl precision. # +# For norms/denorms, scale the exponents such that a multiply # +# instruction won't cause an exception. Use the regular fmul to # +# compute a result. Check if the regular operands would have taken # +# an exception. If so, return the default overflow/underflow result # +# and return the EXOP if exceptions are enabled. Else, scale the # +# result operand to the proper exponent. # +# # +######################################################################### + + align 0x10 +tbl_fmul_ovfl: + long 0x3fff - 0x7ffe # ext_max + long 0x3fff - 0x407e # sgl_max + long 0x3fff - 0x43fe # dbl_max +tbl_fmul_unfl: + long 0x3fff + 0x0001 # ext_unfl + long 0x3fff - 0x3f80 # sgl_unfl + long 0x3fff - 0x3c00 # dbl_unfl + + global fsmul +fsmul: + andi.b &0x30,%d0 # clear rnd prec + ori.b &s_mode*0x10,%d0 # insert sgl prec + bra.b fmul + + global fdmul +fdmul: + andi.b &0x30,%d0 + ori.b &d_mode*0x10,%d0 # insert dbl prec + + global fmul +fmul: + mov.l %d0,L_SCR3(%a6) # store rnd info + + clr.w %d1 + mov.b DTAG(%a6),%d1 + lsl.b &0x3,%d1 + or.b STAG(%a6),%d1 # combine src tags + bne.w fmul_not_norm # optimize on non-norm input + +fmul_norm: + mov.w DST_EX(%a1),FP_SCR1_EX(%a6) + mov.l DST_HI(%a1),FP_SCR1_HI(%a6) + mov.l DST_LO(%a1),FP_SCR1_LO(%a6) + + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + + bsr.l scale_to_zero_src # scale src exponent + mov.l %d0,-(%sp) # save scale factor 1 + + bsr.l scale_to_zero_dst # scale dst exponent + + add.l %d0,(%sp) # SCALE_FACTOR = scale1 + scale2 + + mov.w 2+L_SCR3(%a6),%d1 # fetch precision + lsr.b &0x6,%d1 # shift to lo bits + mov.l (%sp)+,%d0 # load S.F. + cmp.l %d0,(tbl_fmul_ovfl.w,%pc,%d1.w*4) # would result ovfl? + beq.w fmul_may_ovfl # result may rnd to overflow + blt.w fmul_ovfl # result will overflow + + cmp.l %d0,(tbl_fmul_unfl.w,%pc,%d1.w*4) # would result unfl? + beq.w fmul_may_unfl # result may rnd to no unfl + bgt.w fmul_unfl # result will underflow + +# +# NORMAL: +# - the result of the multiply operation will neither overflow nor underflow. +# - do the multiply to the proper precision and rounding mode. +# - scale the result exponent using the scale factor. if both operands were +# normalized then we really don't need to go through this scaling. but for now, +# this will do. +# +fmul_normal: + fmovm.x FP_SCR1(%a6),&0x80 # load dst operand + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fmul.x FP_SCR0(%a6),%fp0 # execute multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fmul_normal_exit: + fmovm.x &0x80,FP_SCR0(%a6) # store out result + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + rts + +# +# OVERFLOW: +# - the result of the multiply operation is an overflow. +# - do the multiply to the proper precision and rounding mode in order to +# set the inexact bits. +# - calculate the default result and return it in fp0. +# - if overflow or inexact is enabled, we need a multiply result rounded to +# extended precision. if the original operation was extended, then we have this +# result. if the original operation was single or double, we have to do another +# multiply using extended precision and the correct rounding mode. the result +# of this operation then has its exponent scaled by -0x6000 to create the +# exceptional operand. +# +fmul_ovfl: + fmovm.x FP_SCR1(%a6),&0x80 # load dst operand + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fmul.x FP_SCR0(%a6),%fp0 # execute multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +# save setting this until now because this is where fmul_may_ovfl may jump in +fmul_ovfl_tst: + or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fmul_ovfl_ena # yes + +# calculate the default result +fmul_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative? + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass rnd prec,mode + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF,N if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + rts + +# +# OVFL is enabled; Create EXOP: +# - if precision is extended, then we have the EXOP. simply bias the exponent +# with an extra -0x6000. if the precision is single or double, we need to +# calculate a result rounded to extended precision. +# +fmul_ovfl_ena: + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # test the rnd prec + bne.b fmul_ovfl_ena_sd # it's sgl or dbl + +fmul_ovfl_ena_cont: + fmovm.x &0x80,FP_SCR0(%a6) # move result to stack + + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.w %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + sub.l %d0,%d1 # add scale factor + subi.l &0x6000,%d1 # subtract bias + andi.w &0x7fff,%d1 # clear sign bit + andi.w &0x8000,%d2 # keep old sign + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.b fmul_ovfl_dis + +fmul_ovfl_ena_sd: + fmovm.x FP_SCR1(%a6),&0x80 # load dst operand + + mov.l L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # keep rnd mode only + fmov.l %d1,%fpcr # set FPCR + + fmul.x FP_SCR0(%a6),%fp0 # execute multiply + + fmov.l &0x0,%fpcr # clear FPCR + bra.b fmul_ovfl_ena_cont + +# +# may OVERFLOW: +# - the result of the multiply operation MAY overflow. +# - do the multiply to the proper precision and rounding mode in order to +# set the inexact bits. +# - calculate the default result and return it in fp0. +# +fmul_may_ovfl: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fmul.x FP_SCR0(%a6),%fp0 # execute multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fabs.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x2 # is |result| >= 2.b? + fbge.w fmul_ovfl_tst # yes; overflow has occurred + +# no, it didn't overflow; we have correct result + bra.w fmul_normal_exit + +# +# UNDERFLOW: +# - the result of the multiply operation is an underflow. +# - do the multiply to the proper precision and rounding mode in order to +# set the inexact bits. +# - calculate the default result and return it in fp0. +# - if overflow or inexact is enabled, we need a multiply result rounded to +# extended precision. if the original operation was extended, then we have this +# result. if the original operation was single or double, we have to do another +# multiply using extended precision and the correct rounding mode. the result +# of this operation then has its exponent scaled by -0x6000 to create the +# exceptional operand. +# +fmul_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + +# for fun, let's use only extended precision, round to zero. then, let +# the unf_res() routine figure out all the rest. +# will we get the correct answer. + fmovm.x FP_SCR1(%a6),&0x80 # load dst operand + + fmov.l &rz_mode*0x10,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fmul.x FP_SCR0(%a6),%fp0 # execute multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fmul_unfl_ena # yes + +fmul_unfl_dis: + fmovm.x &0x80,FP_SCR0(%a6) # store out result + + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # unf_res2 may have set 'Z' + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + rts + +# +# UNFL is enabled. +# +fmul_unfl_ena: + fmovm.x FP_SCR1(%a6),&0x40 # load dst op + + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # is precision extended? + bne.b fmul_unfl_ena_sd # no, sgl or dbl + +# if the rnd mode is anything but RZ, then we have to re-do the above +# multiplication because we used RZ for all. + fmov.l L_SCR3(%a6),%fpcr # set FPCR + +fmul_unfl_ena_cont: + fmov.l &0x0,%fpsr # clear FPSR + + fmul.x FP_SCR0(%a6),%fp1 # execute multiply + + fmov.l &0x0,%fpcr # clear FPCR + + fmovm.x &0x40,FP_SCR0(%a6) # save result to stack + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + addi.l &0x6000,%d1 # add bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.w fmul_unfl_dis + +fmul_unfl_ena_sd: + mov.l L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # use only rnd mode + fmov.l %d1,%fpcr # set FPCR + + bra.b fmul_unfl_ena_cont + +# MAY UNDERFLOW: +# -use the correct rounding mode and precision. this code favors operations +# that do not underflow. +fmul_may_unfl: + fmovm.x FP_SCR1(%a6),&0x80 # load dst operand + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fmul.x FP_SCR0(%a6),%fp0 # execute multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fabs.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x2 # is |result| > 2.b? + fbgt.w fmul_normal_exit # no; no underflow occurred + fblt.w fmul_unfl # yes; underflow occurred + +# +# we still don't know if underflow occurred. result is ~ equal to 2. but, +# we don't know if the result was an underflow that rounded up to a 2 or +# a normalized number that rounded down to a 2. so, redo the entire operation +# using RZ as the rounding mode to see what the pre-rounded result is. +# this case should be relatively rare. +# + fmovm.x FP_SCR1(%a6),&0x40 # load dst operand + + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # keep rnd prec + ori.b &rz_mode*0x10,%d1 # insert RZ + + fmov.l %d1,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fmul.x FP_SCR0(%a6),%fp1 # execute multiply + + fmov.l &0x0,%fpcr # clear FPCR + fabs.x %fp1 # make absolute value + fcmp.b %fp1,&0x2 # is |result| < 2.b? + fbge.w fmul_normal_exit # no; no underflow occurred + bra.w fmul_unfl # yes, underflow occurred + +################################################################################ + +# +# Multiply: inputs are not both normalized; what are they? +# +fmul_not_norm: + mov.w (tbl_fmul_op.b,%pc,%d1.w*2),%d1 + jmp (tbl_fmul_op.b,%pc,%d1.w) + + swbeg &48 +tbl_fmul_op: + short fmul_norm - tbl_fmul_op # NORM x NORM + short fmul_zero - tbl_fmul_op # NORM x ZERO + short fmul_inf_src - tbl_fmul_op # NORM x INF + short fmul_res_qnan - tbl_fmul_op # NORM x QNAN + short fmul_norm - tbl_fmul_op # NORM x DENORM + short fmul_res_snan - tbl_fmul_op # NORM x SNAN + short tbl_fmul_op - tbl_fmul_op # + short tbl_fmul_op - tbl_fmul_op # + + short fmul_zero - tbl_fmul_op # ZERO x NORM + short fmul_zero - tbl_fmul_op # ZERO x ZERO + short fmul_res_operr - tbl_fmul_op # ZERO x INF + short fmul_res_qnan - tbl_fmul_op # ZERO x QNAN + short fmul_zero - tbl_fmul_op # ZERO x DENORM + short fmul_res_snan - tbl_fmul_op # ZERO x SNAN + short tbl_fmul_op - tbl_fmul_op # + short tbl_fmul_op - tbl_fmul_op # + + short fmul_inf_dst - tbl_fmul_op # INF x NORM + short fmul_res_operr - tbl_fmul_op # INF x ZERO + short fmul_inf_dst - tbl_fmul_op # INF x INF + short fmul_res_qnan - tbl_fmul_op # INF x QNAN + short fmul_inf_dst - tbl_fmul_op # INF x DENORM + short fmul_res_snan - tbl_fmul_op # INF x SNAN + short tbl_fmul_op - tbl_fmul_op # + short tbl_fmul_op - tbl_fmul_op # + + short fmul_res_qnan - tbl_fmul_op # QNAN x NORM + short fmul_res_qnan - tbl_fmul_op # QNAN x ZERO + short fmul_res_qnan - tbl_fmul_op # QNAN x INF + short fmul_res_qnan - tbl_fmul_op # QNAN x QNAN + short fmul_res_qnan - tbl_fmul_op # QNAN x DENORM + short fmul_res_snan - tbl_fmul_op # QNAN x SNAN + short tbl_fmul_op - tbl_fmul_op # + short tbl_fmul_op - tbl_fmul_op # + + short fmul_norm - tbl_fmul_op # NORM x NORM + short fmul_zero - tbl_fmul_op # NORM x ZERO + short fmul_inf_src - tbl_fmul_op # NORM x INF + short fmul_res_qnan - tbl_fmul_op # NORM x QNAN + short fmul_norm - tbl_fmul_op # NORM x DENORM + short fmul_res_snan - tbl_fmul_op # NORM x SNAN + short tbl_fmul_op - tbl_fmul_op # + short tbl_fmul_op - tbl_fmul_op # + + short fmul_res_snan - tbl_fmul_op # SNAN x NORM + short fmul_res_snan - tbl_fmul_op # SNAN x ZERO + short fmul_res_snan - tbl_fmul_op # SNAN x INF + short fmul_res_snan - tbl_fmul_op # SNAN x QNAN + short fmul_res_snan - tbl_fmul_op # SNAN x DENORM + short fmul_res_snan - tbl_fmul_op # SNAN x SNAN + short tbl_fmul_op - tbl_fmul_op # + short tbl_fmul_op - tbl_fmul_op # + +fmul_res_operr: + bra.l res_operr +fmul_res_snan: + bra.l res_snan +fmul_res_qnan: + bra.l res_qnan + +# +# Multiply: (Zero x Zero) || (Zero x norm) || (Zero x denorm) +# + global fmul_zero # global for fsglmul +fmul_zero: + mov.b SRC_EX(%a0),%d0 # exclusive or the signs + mov.b DST_EX(%a1),%d1 + eor.b %d0,%d1 + bpl.b fmul_zero_p # result ZERO is pos. +fmul_zero_n: + fmov.s &0x80000000,%fp0 # load -ZERO + mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set Z/N + rts +fmul_zero_p: + fmov.s &0x00000000,%fp0 # load +ZERO + mov.b &z_bmask,FPSR_CC(%a6) # set Z + rts + +# +# Multiply: (inf x inf) || (inf x norm) || (inf x denorm) +# +# Note: The j-bit for an infinity is a don't-care. However, to be +# strictly compatible w/ the 68881/882, we make sure to return an +# INF w/ the j-bit set if the input INF j-bit was set. Destination +# INFs take priority. +# + global fmul_inf_dst # global for fsglmul +fmul_inf_dst: + fmovm.x DST(%a1),&0x80 # return INF result in fp0 + mov.b SRC_EX(%a0),%d0 # exclusive or the signs + mov.b DST_EX(%a1),%d1 + eor.b %d0,%d1 + bpl.b fmul_inf_dst_p # result INF is pos. +fmul_inf_dst_n: + fabs.x %fp0 # clear result sign + fneg.x %fp0 # set result sign + mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set INF/N + rts +fmul_inf_dst_p: + fabs.x %fp0 # clear result sign + mov.b &inf_bmask,FPSR_CC(%a6) # set INF + rts + + global fmul_inf_src # global for fsglmul +fmul_inf_src: + fmovm.x SRC(%a0),&0x80 # return INF result in fp0 + mov.b SRC_EX(%a0),%d0 # exclusive or the signs + mov.b DST_EX(%a1),%d1 + eor.b %d0,%d1 + bpl.b fmul_inf_dst_p # result INF is pos. + bra.b fmul_inf_dst_n + +######################################################################### +# XDEF **************************************************************** # +# fin(): emulates the fmove instruction # +# fsin(): emulates the fsmove instruction # +# fdin(): emulates the fdmove instruction # +# # +# XREF **************************************************************** # +# norm() - normalize mantissa for EXOP on denorm # +# scale_to_zero_src() - scale src exponent to zero # +# ovf_res() - return default overflow result # +# unf_res() - return default underflow result # +# res_qnan_1op() - return QNAN result # +# res_snan_1op() - return SNAN result # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# d0 = round prec/mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, infinities, and zeroes as special cases. Divide # +# norms into extended, single, and double precision. # +# Norms can be emulated w/ a regular fmove instruction. For # +# sgl/dbl, must scale exponent and perform an "fmove". Check to see # +# if the result would have overflowed/underflowed. If so, use unf_res() # +# or ovf_res() to return the default result. Also return EXOP if # +# exception is enabled. If no exception, return the default result. # +# Unnorms don't pass through here. # +# # +######################################################################### + + global fsin +fsin: + andi.b &0x30,%d0 # clear rnd prec + ori.b &s_mode*0x10,%d0 # insert sgl precision + bra.b fin + + global fdin +fdin: + andi.b &0x30,%d0 # clear rnd prec + ori.b &d_mode*0x10,%d0 # insert dbl precision + + global fin +fin: + mov.l %d0,L_SCR3(%a6) # store rnd info + + mov.b STAG(%a6),%d1 # fetch src optype tag + bne.w fin_not_norm # optimize on non-norm input + +# +# FP MOVE IN: NORMs and DENORMs ONLY! +# +fin_norm: + andi.b &0xc0,%d0 # is precision extended? + bne.w fin_not_ext # no, so go handle dbl or sgl + +# +# precision selected is extended. so...we cannot get an underflow +# or overflow because of rounding to the correct precision. so... +# skip the scaling and unscaling... +# + tst.b SRC_EX(%a0) # is the operand negative? + bpl.b fin_norm_done # no + bset &neg_bit,FPSR_CC(%a6) # yes, so set 'N' ccode bit +fin_norm_done: + fmovm.x SRC(%a0),&0x80 # return result in fp0 + rts + +# +# for an extended precision DENORM, the UNFL exception bit is set +# the accrued bit is NOT set in this instance(no inexactness!) +# +fin_denorm: + andi.b &0xc0,%d0 # is precision extended? + bne.w fin_not_ext # no, so go handle dbl or sgl + + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + tst.b SRC_EX(%a0) # is the operand negative? + bpl.b fin_denorm_done # no + bset &neg_bit,FPSR_CC(%a6) # yes, so set 'N' ccode bit +fin_denorm_done: + fmovm.x SRC(%a0),&0x80 # return result in fp0 + btst &unfl_bit,FPCR_ENABLE(%a6) # is UNFL enabled? + bne.b fin_denorm_unfl_ena # yes + rts + +# +# the input is an extended DENORM and underflow is enabled in the FPCR. +# normalize the mantissa and add the bias of 0x6000 to the resulting negative +# exponent and insert back into the operand. +# +fin_denorm_unfl_ena: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + lea FP_SCR0(%a6),%a0 # pass: ptr to operand + bsr.l norm # normalize result + neg.w %d0 # new exponent = -(shft val) + addi.w &0x6000,%d0 # add new bias to exponent + mov.w FP_SCR0_EX(%a6),%d1 # fetch old sign,exp + andi.w &0x8000,%d1 # keep old sign + andi.w &0x7fff,%d0 # clear sign position + or.w %d1,%d0 # concat new exo,old sign + mov.w %d0,FP_SCR0_EX(%a6) # insert new exponent + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + rts + +# +# operand is to be rounded to single or double precision +# +fin_not_ext: + cmpi.b %d0,&s_mode*0x10 # separate sgl/dbl prec + bne.b fin_dbl + +# +# operand is to be rounded to single precision +# +fin_sgl: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + bsr.l scale_to_zero_src # calculate scale factor + + cmpi.l %d0,&0x3fff-0x3f80 # will move in underflow? + bge.w fin_sd_unfl # yes; go handle underflow + cmpi.l %d0,&0x3fff-0x407e # will move in overflow? + beq.w fin_sd_may_ovfl # maybe; go check + blt.w fin_sd_ovfl # yes; go handle overflow + +# +# operand will NOT overflow or underflow when moved into the fp reg file +# +fin_sd_normal: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fmov.x FP_SCR0(%a6),%fp0 # perform move + + fmov.l %fpsr,%d1 # save FPSR + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fin_sd_normal_exit: + mov.l %d2,-(%sp) # save d2 + fmovm.x &0x80,FP_SCR0(%a6) # store out result + mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} + mov.w %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + sub.l %d0,%d1 # add scale factor + andi.w &0x8000,%d2 # keep old sign + or.w %d1,%d2 # concat old sign,new exponent + mov.w %d2,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 + rts + +# +# operand is to be rounded to double precision +# +fin_dbl: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + bsr.l scale_to_zero_src # calculate scale factor + + cmpi.l %d0,&0x3fff-0x3c00 # will move in underflow? + bge.w fin_sd_unfl # yes; go handle underflow + cmpi.l %d0,&0x3fff-0x43fe # will move in overflow? + beq.w fin_sd_may_ovfl # maybe; go check + blt.w fin_sd_ovfl # yes; go handle overflow + bra.w fin_sd_normal # no; ho handle normalized op + +# +# operand WILL underflow when moved in to the fp register file +# +fin_sd_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + tst.b FP_SCR0_EX(%a6) # is operand negative? + bpl.b fin_sd_unfl_tst + bset &neg_bit,FPSR_CC(%a6) # set 'N' ccode bit + +# if underflow or inexact is enabled, then go calculate the EXOP first. +fin_sd_unfl_tst: + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fin_sd_unfl_ena # yes + +fin_sd_unfl_dis: + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # unf_res may have set 'Z' + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + rts + +# +# operand will underflow AND underflow or inexact is enabled. +# Therefore, we must return the result rounded to extended precision. +# +fin_sd_unfl_ena: + mov.l FP_SCR0_HI(%a6),FP_SCR1_HI(%a6) + mov.l FP_SCR0_LO(%a6),FP_SCR1_LO(%a6) + mov.w FP_SCR0_EX(%a6),%d1 # load current exponent + + mov.l %d2,-(%sp) # save d2 + mov.w %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + sub.l %d0,%d1 # subtract scale factor + andi.w &0x8000,%d2 # extract old sign + addi.l &0x6000,%d1 # add new bias + andi.w &0x7fff,%d1 + or.w %d1,%d2 # concat old sign,new exp + mov.w %d2,FP_SCR1_EX(%a6) # insert new exponent + fmovm.x FP_SCR1(%a6),&0x40 # return EXOP in fp1 + mov.l (%sp)+,%d2 # restore d2 + bra.b fin_sd_unfl_dis + +# +# operand WILL overflow. +# +fin_sd_ovfl: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fmov.x FP_SCR0(%a6),%fp0 # perform move + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # save FPSR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fin_sd_ovfl_tst: + or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fin_sd_ovfl_ena # yes + +# +# OVFL is not enabled; therefore, we must create the default result by +# calling ovf_res(). +# +fin_sd_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative? + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass: prec,mode + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF,N if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + rts + +# +# OVFL is enabled. +# the INEX2 bit has already been updated by the round to the correct precision. +# now, round to extended(and don't alter the FPSR). +# +fin_sd_ovfl_ena: + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + sub.l &0x6000,%d1 # subtract bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.b fin_sd_ovfl_dis + +# +# the move in MAY overflow. so... +# +fin_sd_may_ovfl: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fmov.x FP_SCR0(%a6),%fp0 # perform the move + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fabs.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x2 # is |result| >= 2.b? + fbge.w fin_sd_ovfl_tst # yes; overflow has occurred + +# no, it didn't overflow; we have correct result + bra.w fin_sd_normal_exit + +########################################################################## + +# +# operand is not a NORM: check its optype and branch accordingly +# +fin_not_norm: + cmpi.b %d1,&DENORM # weed out DENORM + beq.w fin_denorm + cmpi.b %d1,&SNAN # weed out SNANs + beq.l res_snan_1op + cmpi.b %d1,&QNAN # weed out QNANs + beq.l res_qnan_1op + +# +# do the fmove in; at this point, only possible ops are ZERO and INF. +# use fmov to determine ccodes. +# prec:mode should be zero at this point but it won't affect answer anyways. +# + fmov.x SRC(%a0),%fp0 # do fmove in + fmov.l %fpsr,%d0 # no exceptions possible + rol.l &0x8,%d0 # put ccodes in lo byte + mov.b %d0,FPSR_CC(%a6) # insert correct ccodes + rts + +######################################################################### +# XDEF **************************************************************** # +# fdiv(): emulates the fdiv instruction # +# fsdiv(): emulates the fsdiv instruction # +# fddiv(): emulates the fddiv instruction # +# # +# XREF **************************************************************** # +# scale_to_zero_src() - scale src exponent to zero # +# scale_to_zero_dst() - scale dst exponent to zero # +# unf_res() - return default underflow result # +# ovf_res() - return default overflow result # +# res_qnan() - return QNAN result # +# res_snan() - return SNAN result # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# a1 = pointer to extended precision destination operand # +# d0 rnd prec,mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, infinities, and zeroes as special cases. Divide # +# norms/denorms into ext/sgl/dbl precision. # +# For norms/denorms, scale the exponents such that a divide # +# instruction won't cause an exception. Use the regular fdiv to # +# compute a result. Check if the regular operands would have taken # +# an exception. If so, return the default overflow/underflow result # +# and return the EXOP if exceptions are enabled. Else, scale the # +# result operand to the proper exponent. # +# # +######################################################################### + + align 0x10 +tbl_fdiv_unfl: + long 0x3fff - 0x0000 # ext_unfl + long 0x3fff - 0x3f81 # sgl_unfl + long 0x3fff - 0x3c01 # dbl_unfl + +tbl_fdiv_ovfl: + long 0x3fff - 0x7ffe # ext overflow exponent + long 0x3fff - 0x407e # sgl overflow exponent + long 0x3fff - 0x43fe # dbl overflow exponent + + global fsdiv +fsdiv: + andi.b &0x30,%d0 # clear rnd prec + ori.b &s_mode*0x10,%d0 # insert sgl prec + bra.b fdiv + + global fddiv +fddiv: + andi.b &0x30,%d0 # clear rnd prec + ori.b &d_mode*0x10,%d0 # insert dbl prec + + global fdiv +fdiv: + mov.l %d0,L_SCR3(%a6) # store rnd info + + clr.w %d1 + mov.b DTAG(%a6),%d1 + lsl.b &0x3,%d1 + or.b STAG(%a6),%d1 # combine src tags + + bne.w fdiv_not_norm # optimize on non-norm input + +# +# DIVIDE: NORMs and DENORMs ONLY! +# +fdiv_norm: + mov.w DST_EX(%a1),FP_SCR1_EX(%a6) + mov.l DST_HI(%a1),FP_SCR1_HI(%a6) + mov.l DST_LO(%a1),FP_SCR1_LO(%a6) + + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + + bsr.l scale_to_zero_src # scale src exponent + mov.l %d0,-(%sp) # save scale factor 1 + + bsr.l scale_to_zero_dst # scale dst exponent + + neg.l (%sp) # SCALE FACTOR = scale1 - scale2 + add.l %d0,(%sp) + + mov.w 2+L_SCR3(%a6),%d1 # fetch precision + lsr.b &0x6,%d1 # shift to lo bits + mov.l (%sp)+,%d0 # load S.F. + cmp.l %d0,(tbl_fdiv_ovfl.b,%pc,%d1.w*4) # will result overflow? + ble.w fdiv_may_ovfl # result will overflow + + cmp.l %d0,(tbl_fdiv_unfl.w,%pc,%d1.w*4) # will result underflow? + beq.w fdiv_may_unfl # maybe + bgt.w fdiv_unfl # yes; go handle underflow + +fdiv_normal: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # save FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fdiv.x FP_SCR0(%a6),%fp0 # perform divide + + fmov.l %fpsr,%d1 # save FPSR + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fdiv_normal_exit: + fmovm.x &0x80,FP_SCR0(%a6) # store result on stack + mov.l %d2,-(%sp) # store d2 + mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 + rts + +tbl_fdiv_ovfl2: + long 0x7fff + long 0x407f + long 0x43ff + +fdiv_no_ovfl: + mov.l (%sp)+,%d0 # restore scale factor + bra.b fdiv_normal_exit + +fdiv_may_ovfl: + mov.l %d0,-(%sp) # save scale factor + + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # set FPSR + + fdiv.x FP_SCR0(%a6),%fp0 # execute divide + + fmov.l %fpsr,%d0 + fmov.l &0x0,%fpcr + + or.l %d0,USER_FPSR(%a6) # save INEX,N + + fmovm.x &0x01,-(%sp) # save result to stack + mov.w (%sp),%d0 # fetch new exponent + add.l &0xc,%sp # clear result from stack + andi.l &0x7fff,%d0 # strip sign + sub.l (%sp),%d0 # add scale factor + cmp.l %d0,(tbl_fdiv_ovfl2.b,%pc,%d1.w*4) + blt.b fdiv_no_ovfl + mov.l (%sp)+,%d0 + +fdiv_ovfl_tst: + or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fdiv_ovfl_ena # yes + +fdiv_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative? + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass prec:rnd + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + rts + +fdiv_ovfl_ena: + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # is precision extended? + bne.b fdiv_ovfl_ena_sd # no, do sgl or dbl + +fdiv_ovfl_ena_cont: + fmovm.x &0x80,FP_SCR0(%a6) # move result to stack + + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.w %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + sub.l %d0,%d1 # add scale factor + subi.l &0x6000,%d1 # subtract bias + andi.w &0x7fff,%d1 # clear sign bit + andi.w &0x8000,%d2 # keep old sign + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.b fdiv_ovfl_dis + +fdiv_ovfl_ena_sd: + fmovm.x FP_SCR1(%a6),&0x80 # load dst operand + + mov.l L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # keep rnd mode + fmov.l %d1,%fpcr # set FPCR + + fdiv.x FP_SCR0(%a6),%fp0 # execute divide + + fmov.l &0x0,%fpcr # clear FPCR + bra.b fdiv_ovfl_ena_cont + +fdiv_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l &rz_mode*0x10,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fdiv.x FP_SCR0(%a6),%fp0 # execute divide + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fdiv_unfl_ena # yes + +fdiv_unfl_dis: + fmovm.x &0x80,FP_SCR0(%a6) # store out result + + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # 'Z' may have been set + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + rts + +# +# UNFL is enabled. +# +fdiv_unfl_ena: + fmovm.x FP_SCR1(%a6),&0x40 # load dst op + + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # is precision extended? + bne.b fdiv_unfl_ena_sd # no, sgl or dbl + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + +fdiv_unfl_ena_cont: + fmov.l &0x0,%fpsr # clear FPSR + + fdiv.x FP_SCR0(%a6),%fp1 # execute divide + + fmov.l &0x0,%fpcr # clear FPCR + + fmovm.x &0x40,FP_SCR0(%a6) # save result to stack + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factoer + addi.l &0x6000,%d1 # add bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exp + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.w fdiv_unfl_dis + +fdiv_unfl_ena_sd: + mov.l L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # use only rnd mode + fmov.l %d1,%fpcr # set FPCR + + bra.b fdiv_unfl_ena_cont + +# +# the divide operation MAY underflow: +# +fdiv_may_unfl: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fdiv.x FP_SCR0(%a6),%fp0 # execute divide + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fabs.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x1 # is |result| > 1.b? + fbgt.w fdiv_normal_exit # no; no underflow occurred + fblt.w fdiv_unfl # yes; underflow occurred + +# +# we still don't know if underflow occurred. result is ~ equal to 1. but, +# we don't know if the result was an underflow that rounded up to a 1 +# or a normalized number that rounded down to a 1. so, redo the entire +# operation using RZ as the rounding mode to see what the pre-rounded +# result is. this case should be relatively rare. +# + fmovm.x FP_SCR1(%a6),&0x40 # load dst op into fp1 + + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # keep rnd prec + ori.b &rz_mode*0x10,%d1 # insert RZ + + fmov.l %d1,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fdiv.x FP_SCR0(%a6),%fp1 # execute divide + + fmov.l &0x0,%fpcr # clear FPCR + fabs.x %fp1 # make absolute value + fcmp.b %fp1,&0x1 # is |result| < 1.b? + fbge.w fdiv_normal_exit # no; no underflow occurred + bra.w fdiv_unfl # yes; underflow occurred + +############################################################################ + +# +# Divide: inputs are not both normalized; what are they? +# +fdiv_not_norm: + mov.w (tbl_fdiv_op.b,%pc,%d1.w*2),%d1 + jmp (tbl_fdiv_op.b,%pc,%d1.w*1) + + swbeg &48 +tbl_fdiv_op: + short fdiv_norm - tbl_fdiv_op # NORM / NORM + short fdiv_inf_load - tbl_fdiv_op # NORM / ZERO + short fdiv_zero_load - tbl_fdiv_op # NORM / INF + short fdiv_res_qnan - tbl_fdiv_op # NORM / QNAN + short fdiv_norm - tbl_fdiv_op # NORM / DENORM + short fdiv_res_snan - tbl_fdiv_op # NORM / SNAN + short tbl_fdiv_op - tbl_fdiv_op # + short tbl_fdiv_op - tbl_fdiv_op # + + short fdiv_zero_load - tbl_fdiv_op # ZERO / NORM + short fdiv_res_operr - tbl_fdiv_op # ZERO / ZERO + short fdiv_zero_load - tbl_fdiv_op # ZERO / INF + short fdiv_res_qnan - tbl_fdiv_op # ZERO / QNAN + short fdiv_zero_load - tbl_fdiv_op # ZERO / DENORM + short fdiv_res_snan - tbl_fdiv_op # ZERO / SNAN + short tbl_fdiv_op - tbl_fdiv_op # + short tbl_fdiv_op - tbl_fdiv_op # + + short fdiv_inf_dst - tbl_fdiv_op # INF / NORM + short fdiv_inf_dst - tbl_fdiv_op # INF / ZERO + short fdiv_res_operr - tbl_fdiv_op # INF / INF + short fdiv_res_qnan - tbl_fdiv_op # INF / QNAN + short fdiv_inf_dst - tbl_fdiv_op # INF / DENORM + short fdiv_res_snan - tbl_fdiv_op # INF / SNAN + short tbl_fdiv_op - tbl_fdiv_op # + short tbl_fdiv_op - tbl_fdiv_op # + + short fdiv_res_qnan - tbl_fdiv_op # QNAN / NORM + short fdiv_res_qnan - tbl_fdiv_op # QNAN / ZERO + short fdiv_res_qnan - tbl_fdiv_op # QNAN / INF + short fdiv_res_qnan - tbl_fdiv_op # QNAN / QNAN + short fdiv_res_qnan - tbl_fdiv_op # QNAN / DENORM + short fdiv_res_snan - tbl_fdiv_op # QNAN / SNAN + short tbl_fdiv_op - tbl_fdiv_op # + short tbl_fdiv_op - tbl_fdiv_op # + + short fdiv_norm - tbl_fdiv_op # DENORM / NORM + short fdiv_inf_load - tbl_fdiv_op # DENORM / ZERO + short fdiv_zero_load - tbl_fdiv_op # DENORM / INF + short fdiv_res_qnan - tbl_fdiv_op # DENORM / QNAN + short fdiv_norm - tbl_fdiv_op # DENORM / DENORM + short fdiv_res_snan - tbl_fdiv_op # DENORM / SNAN + short tbl_fdiv_op - tbl_fdiv_op # + short tbl_fdiv_op - tbl_fdiv_op # + + short fdiv_res_snan - tbl_fdiv_op # SNAN / NORM + short fdiv_res_snan - tbl_fdiv_op # SNAN / ZERO + short fdiv_res_snan - tbl_fdiv_op # SNAN / INF + short fdiv_res_snan - tbl_fdiv_op # SNAN / QNAN + short fdiv_res_snan - tbl_fdiv_op # SNAN / DENORM + short fdiv_res_snan - tbl_fdiv_op # SNAN / SNAN + short tbl_fdiv_op - tbl_fdiv_op # + short tbl_fdiv_op - tbl_fdiv_op # + +fdiv_res_qnan: + bra.l res_qnan +fdiv_res_snan: + bra.l res_snan +fdiv_res_operr: + bra.l res_operr + + global fdiv_zero_load # global for fsgldiv +fdiv_zero_load: + mov.b SRC_EX(%a0),%d0 # result sign is exclusive + mov.b DST_EX(%a1),%d1 # or of input signs. + eor.b %d0,%d1 + bpl.b fdiv_zero_load_p # result is positive + fmov.s &0x80000000,%fp0 # load a -ZERO + mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set Z/N + rts +fdiv_zero_load_p: + fmov.s &0x00000000,%fp0 # load a +ZERO + mov.b &z_bmask,FPSR_CC(%a6) # set Z + rts + +# +# The destination was In Range and the source was a ZERO. The result, +# Therefore, is an INF w/ the proper sign. +# So, determine the sign and return a new INF (w/ the j-bit cleared). +# + global fdiv_inf_load # global for fsgldiv +fdiv_inf_load: + ori.w &dz_mask+adz_mask,2+USER_FPSR(%a6) # no; set DZ/ADZ + mov.b SRC_EX(%a0),%d0 # load both signs + mov.b DST_EX(%a1),%d1 + eor.b %d0,%d1 + bpl.b fdiv_inf_load_p # result is positive + fmov.s &0xff800000,%fp0 # make result -INF + mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set INF/N + rts +fdiv_inf_load_p: + fmov.s &0x7f800000,%fp0 # make result +INF + mov.b &inf_bmask,FPSR_CC(%a6) # set INF + rts + +# +# The destination was an INF w/ an In Range or ZERO source, the result is +# an INF w/ the proper sign. +# The 68881/882 returns the destination INF w/ the new sign(if the j-bit of the +# dst INF is set, then then j-bit of the result INF is also set). +# + global fdiv_inf_dst # global for fsgldiv +fdiv_inf_dst: + mov.b DST_EX(%a1),%d0 # load both signs + mov.b SRC_EX(%a0),%d1 + eor.b %d0,%d1 + bpl.b fdiv_inf_dst_p # result is positive + + fmovm.x DST(%a1),&0x80 # return result in fp0 + fabs.x %fp0 # clear sign bit + fneg.x %fp0 # set sign bit + mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set INF/NEG + rts + +fdiv_inf_dst_p: + fmovm.x DST(%a1),&0x80 # return result in fp0 + fabs.x %fp0 # return positive INF + mov.b &inf_bmask,FPSR_CC(%a6) # set INF + rts + +######################################################################### +# XDEF **************************************************************** # +# fneg(): emulates the fneg instruction # +# fsneg(): emulates the fsneg instruction # +# fdneg(): emulates the fdneg instruction # +# # +# XREF **************************************************************** # +# norm() - normalize a denorm to provide EXOP # +# scale_to_zero_src() - scale sgl/dbl source exponent # +# ovf_res() - return default overflow result # +# unf_res() - return default underflow result # +# res_qnan_1op() - return QNAN result # +# res_snan_1op() - return SNAN result # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# d0 = rnd prec,mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, zeroes, and infinities as special cases. Separate # +# norms/denorms into ext/sgl/dbl precisions. Extended precision can be # +# emulated by simply setting sign bit. Sgl/dbl operands must be scaled # +# and an actual fneg performed to see if overflow/underflow would have # +# occurred. If so, return default underflow/overflow result. Else, # +# scale the result exponent and return result. FPSR gets set based on # +# the result value. # +# # +######################################################################### + + global fsneg +fsneg: + andi.b &0x30,%d0 # clear rnd prec + ori.b &s_mode*0x10,%d0 # insert sgl precision + bra.b fneg + + global fdneg +fdneg: + andi.b &0x30,%d0 # clear rnd prec + ori.b &d_mode*0x10,%d0 # insert dbl prec + + global fneg +fneg: + mov.l %d0,L_SCR3(%a6) # store rnd info + mov.b STAG(%a6),%d1 + bne.w fneg_not_norm # optimize on non-norm input + +# +# NEGATE SIGN : norms and denorms ONLY! +# +fneg_norm: + andi.b &0xc0,%d0 # is precision extended? + bne.w fneg_not_ext # no; go handle sgl or dbl + +# +# precision selected is extended. so...we can not get an underflow +# or overflow because of rounding to the correct precision. so... +# skip the scaling and unscaling... +# + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + mov.w SRC_EX(%a0),%d0 + eori.w &0x8000,%d0 # negate sign + bpl.b fneg_norm_load # sign is positive + mov.b &neg_bmask,FPSR_CC(%a6) # set 'N' ccode bit +fneg_norm_load: + mov.w %d0,FP_SCR0_EX(%a6) + fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 + rts + +# +# for an extended precision DENORM, the UNFL exception bit is set +# the accrued bit is NOT set in this instance(no inexactness!) +# +fneg_denorm: + andi.b &0xc0,%d0 # is precision extended? + bne.b fneg_not_ext # no; go handle sgl or dbl + + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + mov.w SRC_EX(%a0),%d0 + eori.w &0x8000,%d0 # negate sign + bpl.b fneg_denorm_done # no + mov.b &neg_bmask,FPSR_CC(%a6) # yes, set 'N' ccode bit +fneg_denorm_done: + mov.w %d0,FP_SCR0_EX(%a6) + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + + btst &unfl_bit,FPCR_ENABLE(%a6) # is UNFL enabled? + bne.b fneg_ext_unfl_ena # yes + rts + +# +# the input is an extended DENORM and underflow is enabled in the FPCR. +# normalize the mantissa and add the bias of 0x6000 to the resulting negative +# exponent and insert back into the operand. +# +fneg_ext_unfl_ena: + lea FP_SCR0(%a6),%a0 # pass: ptr to operand + bsr.l norm # normalize result + neg.w %d0 # new exponent = -(shft val) + addi.w &0x6000,%d0 # add new bias to exponent + mov.w FP_SCR0_EX(%a6),%d1 # fetch old sign,exp + andi.w &0x8000,%d1 # keep old sign + andi.w &0x7fff,%d0 # clear sign position + or.w %d1,%d0 # concat old sign, new exponent + mov.w %d0,FP_SCR0_EX(%a6) # insert new exponent + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + rts + +# +# operand is either single or double +# +fneg_not_ext: + cmpi.b %d0,&s_mode*0x10 # separate sgl/dbl prec + bne.b fneg_dbl + +# +# operand is to be rounded to single precision +# +fneg_sgl: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + bsr.l scale_to_zero_src # calculate scale factor + + cmpi.l %d0,&0x3fff-0x3f80 # will move in underflow? + bge.w fneg_sd_unfl # yes; go handle underflow + cmpi.l %d0,&0x3fff-0x407e # will move in overflow? + beq.w fneg_sd_may_ovfl # maybe; go check + blt.w fneg_sd_ovfl # yes; go handle overflow + +# +# operand will NOT overflow or underflow when moved in to the fp reg file +# +fneg_sd_normal: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fneg.x FP_SCR0(%a6),%fp0 # perform negation + + fmov.l %fpsr,%d1 # save FPSR + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fneg_sd_normal_exit: + mov.l %d2,-(%sp) # save d2 + fmovm.x &0x80,FP_SCR0(%a6) # store out result + mov.w FP_SCR0_EX(%a6),%d1 # load sgn,exp + mov.w %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + sub.l %d0,%d1 # add scale factor + andi.w &0x8000,%d2 # keep old sign + or.w %d1,%d2 # concat old sign,new exp + mov.w %d2,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 + rts + +# +# operand is to be rounded to double precision +# +fneg_dbl: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + bsr.l scale_to_zero_src # calculate scale factor + + cmpi.l %d0,&0x3fff-0x3c00 # will move in underflow? + bge.b fneg_sd_unfl # yes; go handle underflow + cmpi.l %d0,&0x3fff-0x43fe # will move in overflow? + beq.w fneg_sd_may_ovfl # maybe; go check + blt.w fneg_sd_ovfl # yes; go handle overflow + bra.w fneg_sd_normal # no; ho handle normalized op + +# +# operand WILL underflow when moved in to the fp register file +# +fneg_sd_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + eori.b &0x80,FP_SCR0_EX(%a6) # negate sign + bpl.b fneg_sd_unfl_tst + bset &neg_bit,FPSR_CC(%a6) # set 'N' ccode bit + +# if underflow or inexact is enabled, go calculate EXOP first. +fneg_sd_unfl_tst: + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fneg_sd_unfl_ena # yes + +fneg_sd_unfl_dis: + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # unf_res may have set 'Z' + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + rts + +# +# operand will underflow AND underflow is enabled. +# Therefore, we must return the result rounded to extended precision. +# +fneg_sd_unfl_ena: + mov.l FP_SCR0_HI(%a6),FP_SCR1_HI(%a6) + mov.l FP_SCR0_LO(%a6),FP_SCR1_LO(%a6) + mov.w FP_SCR0_EX(%a6),%d1 # load current exponent + + mov.l %d2,-(%sp) # save d2 + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # subtract scale factor + addi.l &0x6000,%d1 # add new bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 # concat new sign,new exp + mov.w %d1,FP_SCR1_EX(%a6) # insert new exp + fmovm.x FP_SCR1(%a6),&0x40 # return EXOP in fp1 + mov.l (%sp)+,%d2 # restore d2 + bra.b fneg_sd_unfl_dis + +# +# operand WILL overflow. +# +fneg_sd_ovfl: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fneg.x FP_SCR0(%a6),%fp0 # perform negation + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # save FPSR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fneg_sd_ovfl_tst: + or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fneg_sd_ovfl_ena # yes + +# +# OVFL is not enabled; therefore, we must create the default result by +# calling ovf_res(). +# +fneg_sd_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative? + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass: prec,mode + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF,N if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + rts + +# +# OVFL is enabled. +# the INEX2 bit has already been updated by the round to the correct precision. +# now, round to extended(and don't alter the FPSR). +# +fneg_sd_ovfl_ena: + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + subi.l &0x6000,%d1 # subtract bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 # concat sign,exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + mov.l (%sp)+,%d2 # restore d2 + bra.b fneg_sd_ovfl_dis + +# +# the move in MAY underflow. so... +# +fneg_sd_may_ovfl: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fneg.x FP_SCR0(%a6),%fp0 # perform negation + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fabs.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x2 # is |result| >= 2.b? + fbge.w fneg_sd_ovfl_tst # yes; overflow has occurred + +# no, it didn't overflow; we have correct result + bra.w fneg_sd_normal_exit + +########################################################################## + +# +# input is not normalized; what is it? +# +fneg_not_norm: + cmpi.b %d1,&DENORM # weed out DENORM + beq.w fneg_denorm + cmpi.b %d1,&SNAN # weed out SNAN + beq.l res_snan_1op + cmpi.b %d1,&QNAN # weed out QNAN + beq.l res_qnan_1op + +# +# do the fneg; at this point, only possible ops are ZERO and INF. +# use fneg to determine ccodes. +# prec:mode should be zero at this point but it won't affect answer anyways. +# + fneg.x SRC_EX(%a0),%fp0 # do fneg + fmov.l %fpsr,%d0 + rol.l &0x8,%d0 # put ccodes in lo byte + mov.b %d0,FPSR_CC(%a6) # insert correct ccodes + rts + +######################################################################### +# XDEF **************************************************************** # +# ftst(): emulates the ftest instruction # +# # +# XREF **************************************************************** # +# res{s,q}nan_1op() - set NAN result for monadic instruction # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# # +# OUTPUT ************************************************************** # +# none # +# # +# ALGORITHM *********************************************************** # +# Check the source operand tag (STAG) and set the FPCR according # +# to the operand type and sign. # +# # +######################################################################### + + global ftst +ftst: + mov.b STAG(%a6),%d1 + bne.b ftst_not_norm # optimize on non-norm input + +# +# Norm: +# +ftst_norm: + tst.b SRC_EX(%a0) # is operand negative? + bmi.b ftst_norm_m # yes + rts +ftst_norm_m: + mov.b &neg_bmask,FPSR_CC(%a6) # set 'N' ccode bit + rts + +# +# input is not normalized; what is it? +# +ftst_not_norm: + cmpi.b %d1,&ZERO # weed out ZERO + beq.b ftst_zero + cmpi.b %d1,&INF # weed out INF + beq.b ftst_inf + cmpi.b %d1,&SNAN # weed out SNAN + beq.l res_snan_1op + cmpi.b %d1,&QNAN # weed out QNAN + beq.l res_qnan_1op + +# +# Denorm: +# +ftst_denorm: + tst.b SRC_EX(%a0) # is operand negative? + bmi.b ftst_denorm_m # yes + rts +ftst_denorm_m: + mov.b &neg_bmask,FPSR_CC(%a6) # set 'N' ccode bit + rts + +# +# Infinity: +# +ftst_inf: + tst.b SRC_EX(%a0) # is operand negative? + bmi.b ftst_inf_m # yes +ftst_inf_p: + mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit + rts +ftst_inf_m: + mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set 'I','N' ccode bits + rts + +# +# Zero: +# +ftst_zero: + tst.b SRC_EX(%a0) # is operand negative? + bmi.b ftst_zero_m # yes +ftst_zero_p: + mov.b &z_bmask,FPSR_CC(%a6) # set 'N' ccode bit + rts +ftst_zero_m: + mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set 'Z','N' ccode bits + rts + +######################################################################### +# XDEF **************************************************************** # +# fint(): emulates the fint instruction # +# # +# XREF **************************************************************** # +# res_{s,q}nan_1op() - set NAN result for monadic operation # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# d0 = round precision/mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# # +# ALGORITHM *********************************************************** # +# Separate according to operand type. Unnorms don't pass through # +# here. For norms, load the rounding mode/prec, execute a "fint", then # +# store the resulting FPSR bits. # +# For denorms, force the j-bit to a one and do the same as for # +# norms. Denorms are so low that the answer will either be a zero or a # +# one. # +# For zeroes/infs/NANs, return the same while setting the FPSR # +# as appropriate. # +# # +######################################################################### + + global fint +fint: + mov.b STAG(%a6),%d1 + bne.b fint_not_norm # optimize on non-norm input + +# +# Norm: +# +fint_norm: + andi.b &0x30,%d0 # set prec = ext + + fmov.l %d0,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fint.x SRC(%a0),%fp0 # execute fint + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d0 # save FPSR + or.l %d0,USER_FPSR(%a6) # set exception bits + + rts + +# +# input is not normalized; what is it? +# +fint_not_norm: + cmpi.b %d1,&ZERO # weed out ZERO + beq.b fint_zero + cmpi.b %d1,&INF # weed out INF + beq.b fint_inf + cmpi.b %d1,&DENORM # weed out DENORM + beq.b fint_denorm + cmpi.b %d1,&SNAN # weed out SNAN + beq.l res_snan_1op + bra.l res_qnan_1op # weed out QNAN + +# +# Denorm: +# +# for DENORMs, the result will be either (+/-)ZERO or (+/-)1. +# also, the INEX2 and AINEX exception bits will be set. +# so, we could either set these manually or force the DENORM +# to a very small NORM and ship it to the NORM routine. +# I do the latter. +# +fint_denorm: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) # copy sign, zero exp + mov.b &0x80,FP_SCR0_HI(%a6) # force DENORM ==> small NORM + lea FP_SCR0(%a6),%a0 + bra.b fint_norm + +# +# Zero: +# +fint_zero: + tst.b SRC_EX(%a0) # is ZERO negative? + bmi.b fint_zero_m # yes +fint_zero_p: + fmov.s &0x00000000,%fp0 # return +ZERO in fp0 + mov.b &z_bmask,FPSR_CC(%a6) # set 'Z' ccode bit + rts +fint_zero_m: + fmov.s &0x80000000,%fp0 # return -ZERO in fp0 + mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set 'Z','N' ccode bits + rts + +# +# Infinity: +# +fint_inf: + fmovm.x SRC(%a0),&0x80 # return result in fp0 + tst.b SRC_EX(%a0) # is INF negative? + bmi.b fint_inf_m # yes +fint_inf_p: + mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit + rts +fint_inf_m: + mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set 'N','I' ccode bits + rts + +######################################################################### +# XDEF **************************************************************** # +# fintrz(): emulates the fintrz instruction # +# # +# XREF **************************************************************** # +# res_{s,q}nan_1op() - set NAN result for monadic operation # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# d0 = round precision/mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# # +# ALGORITHM *********************************************************** # +# Separate according to operand type. Unnorms don't pass through # +# here. For norms, load the rounding mode/prec, execute a "fintrz", # +# then store the resulting FPSR bits. # +# For denorms, force the j-bit to a one and do the same as for # +# norms. Denorms are so low that the answer will either be a zero or a # +# one. # +# For zeroes/infs/NANs, return the same while setting the FPSR # +# as appropriate. # +# # +######################################################################### + + global fintrz +fintrz: + mov.b STAG(%a6),%d1 + bne.b fintrz_not_norm # optimize on non-norm input + +# +# Norm: +# +fintrz_norm: + fmov.l &0x0,%fpsr # clear FPSR + + fintrz.x SRC(%a0),%fp0 # execute fintrz + + fmov.l %fpsr,%d0 # save FPSR + or.l %d0,USER_FPSR(%a6) # set exception bits + + rts + +# +# input is not normalized; what is it? +# +fintrz_not_norm: + cmpi.b %d1,&ZERO # weed out ZERO + beq.b fintrz_zero + cmpi.b %d1,&INF # weed out INF + beq.b fintrz_inf + cmpi.b %d1,&DENORM # weed out DENORM + beq.b fintrz_denorm + cmpi.b %d1,&SNAN # weed out SNAN + beq.l res_snan_1op + bra.l res_qnan_1op # weed out QNAN + +# +# Denorm: +# +# for DENORMs, the result will be (+/-)ZERO. +# also, the INEX2 and AINEX exception bits will be set. +# so, we could either set these manually or force the DENORM +# to a very small NORM and ship it to the NORM routine. +# I do the latter. +# +fintrz_denorm: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) # copy sign, zero exp + mov.b &0x80,FP_SCR0_HI(%a6) # force DENORM ==> small NORM + lea FP_SCR0(%a6),%a0 + bra.b fintrz_norm + +# +# Zero: +# +fintrz_zero: + tst.b SRC_EX(%a0) # is ZERO negative? + bmi.b fintrz_zero_m # yes +fintrz_zero_p: + fmov.s &0x00000000,%fp0 # return +ZERO in fp0 + mov.b &z_bmask,FPSR_CC(%a6) # set 'Z' ccode bit + rts +fintrz_zero_m: + fmov.s &0x80000000,%fp0 # return -ZERO in fp0 + mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set 'Z','N' ccode bits + rts + +# +# Infinity: +# +fintrz_inf: + fmovm.x SRC(%a0),&0x80 # return result in fp0 + tst.b SRC_EX(%a0) # is INF negative? + bmi.b fintrz_inf_m # yes +fintrz_inf_p: + mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit + rts +fintrz_inf_m: + mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set 'N','I' ccode bits + rts + +######################################################################### +# XDEF **************************************************************** # +# fabs(): emulates the fabs instruction # +# fsabs(): emulates the fsabs instruction # +# fdabs(): emulates the fdabs instruction # +# # +# XREF **************************************************************** # +# norm() - normalize denorm mantissa to provide EXOP # +# scale_to_zero_src() - make exponent. = 0; get scale factor # +# unf_res() - calculate underflow result # +# ovf_res() - calculate overflow result # +# res_{s,q}nan_1op() - set NAN result for monadic operation # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# d0 = rnd precision/mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, infinities, and zeroes as special cases. Divide # +# norms into extended, single, and double precision. # +# Simply clear sign for extended precision norm. Ext prec denorm # +# gets an EXOP created for it since it's an underflow. # +# Double and single precision can overflow and underflow. First, # +# scale the operand such that the exponent is zero. Perform an "fabs" # +# using the correct rnd mode/prec. Check to see if the original # +# exponent would take an exception. If so, use unf_res() or ovf_res() # +# to calculate the default result. Also, create the EXOP for the # +# exceptional case. If no exception should occur, insert the correct # +# result exponent and return. # +# Unnorms don't pass through here. # +# # +######################################################################### + + global fsabs +fsabs: + andi.b &0x30,%d0 # clear rnd prec + ori.b &s_mode*0x10,%d0 # insert sgl precision + bra.b fabs + + global fdabs +fdabs: + andi.b &0x30,%d0 # clear rnd prec + ori.b &d_mode*0x10,%d0 # insert dbl precision + + global fabs +fabs: + mov.l %d0,L_SCR3(%a6) # store rnd info + mov.b STAG(%a6),%d1 + bne.w fabs_not_norm # optimize on non-norm input + +# +# ABSOLUTE VALUE: norms and denorms ONLY! +# +fabs_norm: + andi.b &0xc0,%d0 # is precision extended? + bne.b fabs_not_ext # no; go handle sgl or dbl + +# +# precision selected is extended. so...we can not get an underflow +# or overflow because of rounding to the correct precision. so... +# skip the scaling and unscaling... +# + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + mov.w SRC_EX(%a0),%d1 + bclr &15,%d1 # force absolute value + mov.w %d1,FP_SCR0_EX(%a6) # insert exponent + fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 + rts + +# +# for an extended precision DENORM, the UNFL exception bit is set +# the accrued bit is NOT set in this instance(no inexactness!) +# +fabs_denorm: + andi.b &0xc0,%d0 # is precision extended? + bne.b fabs_not_ext # no + + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + mov.w SRC_EX(%a0),%d0 + bclr &15,%d0 # clear sign + mov.w %d0,FP_SCR0_EX(%a6) # insert exponent + + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + + btst &unfl_bit,FPCR_ENABLE(%a6) # is UNFL enabled? + bne.b fabs_ext_unfl_ena + rts + +# +# the input is an extended DENORM and underflow is enabled in the FPCR. +# normalize the mantissa and add the bias of 0x6000 to the resulting negative +# exponent and insert back into the operand. +# +fabs_ext_unfl_ena: + lea FP_SCR0(%a6),%a0 # pass: ptr to operand + bsr.l norm # normalize result + neg.w %d0 # new exponent = -(shft val) + addi.w &0x6000,%d0 # add new bias to exponent + mov.w FP_SCR0_EX(%a6),%d1 # fetch old sign,exp + andi.w &0x8000,%d1 # keep old sign + andi.w &0x7fff,%d0 # clear sign position + or.w %d1,%d0 # concat old sign, new exponent + mov.w %d0,FP_SCR0_EX(%a6) # insert new exponent + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + rts + +# +# operand is either single or double +# +fabs_not_ext: + cmpi.b %d0,&s_mode*0x10 # separate sgl/dbl prec + bne.b fabs_dbl + +# +# operand is to be rounded to single precision +# +fabs_sgl: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + bsr.l scale_to_zero_src # calculate scale factor + + cmpi.l %d0,&0x3fff-0x3f80 # will move in underflow? + bge.w fabs_sd_unfl # yes; go handle underflow + cmpi.l %d0,&0x3fff-0x407e # will move in overflow? + beq.w fabs_sd_may_ovfl # maybe; go check + blt.w fabs_sd_ovfl # yes; go handle overflow + +# +# operand will NOT overflow or underflow when moved in to the fp reg file +# +fabs_sd_normal: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fabs.x FP_SCR0(%a6),%fp0 # perform absolute + + fmov.l %fpsr,%d1 # save FPSR + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fabs_sd_normal_exit: + mov.l %d2,-(%sp) # save d2 + fmovm.x &0x80,FP_SCR0(%a6) # store out result + mov.w FP_SCR0_EX(%a6),%d1 # load sgn,exp + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + sub.l %d0,%d1 # add scale factor + andi.w &0x8000,%d2 # keep old sign + or.w %d1,%d2 # concat old sign,new exp + mov.w %d2,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 + rts + +# +# operand is to be rounded to double precision +# +fabs_dbl: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + bsr.l scale_to_zero_src # calculate scale factor + + cmpi.l %d0,&0x3fff-0x3c00 # will move in underflow? + bge.b fabs_sd_unfl # yes; go handle underflow + cmpi.l %d0,&0x3fff-0x43fe # will move in overflow? + beq.w fabs_sd_may_ovfl # maybe; go check + blt.w fabs_sd_ovfl # yes; go handle overflow + bra.w fabs_sd_normal # no; ho handle normalized op + +# +# operand WILL underflow when moved in to the fp register file +# +fabs_sd_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + bclr &0x7,FP_SCR0_EX(%a6) # force absolute value + +# if underflow or inexact is enabled, go calculate EXOP first. + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fabs_sd_unfl_ena # yes + +fabs_sd_unfl_dis: + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set possible 'Z' ccode + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + rts + +# +# operand will underflow AND underflow is enabled. +# Therefore, we must return the result rounded to extended precision. +# +fabs_sd_unfl_ena: + mov.l FP_SCR0_HI(%a6),FP_SCR1_HI(%a6) + mov.l FP_SCR0_LO(%a6),FP_SCR1_LO(%a6) + mov.w FP_SCR0_EX(%a6),%d1 # load current exponent + + mov.l %d2,-(%sp) # save d2 + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # subtract scale factor + addi.l &0x6000,%d1 # add new bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 # concat new sign,new exp + mov.w %d1,FP_SCR1_EX(%a6) # insert new exp + fmovm.x FP_SCR1(%a6),&0x40 # return EXOP in fp1 + mov.l (%sp)+,%d2 # restore d2 + bra.b fabs_sd_unfl_dis + +# +# operand WILL overflow. +# +fabs_sd_ovfl: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fabs.x FP_SCR0(%a6),%fp0 # perform absolute + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # save FPSR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fabs_sd_ovfl_tst: + or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fabs_sd_ovfl_ena # yes + +# +# OVFL is not enabled; therefore, we must create the default result by +# calling ovf_res(). +# +fabs_sd_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative? + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass: prec,mode + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF,N if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + rts + +# +# OVFL is enabled. +# the INEX2 bit has already been updated by the round to the correct precision. +# now, round to extended(and don't alter the FPSR). +# +fabs_sd_ovfl_ena: + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + subi.l &0x6000,%d1 # subtract bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 # concat sign,exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + mov.l (%sp)+,%d2 # restore d2 + bra.b fabs_sd_ovfl_dis + +# +# the move in MAY underflow. so... +# +fabs_sd_may_ovfl: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fabs.x FP_SCR0(%a6),%fp0 # perform absolute + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fabs.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x2 # is |result| >= 2.b? + fbge.w fabs_sd_ovfl_tst # yes; overflow has occurred + +# no, it didn't overflow; we have correct result + bra.w fabs_sd_normal_exit + +########################################################################## + +# +# input is not normalized; what is it? +# +fabs_not_norm: + cmpi.b %d1,&DENORM # weed out DENORM + beq.w fabs_denorm + cmpi.b %d1,&SNAN # weed out SNAN + beq.l res_snan_1op + cmpi.b %d1,&QNAN # weed out QNAN + beq.l res_qnan_1op + + fabs.x SRC(%a0),%fp0 # force absolute value + + cmpi.b %d1,&INF # weed out INF + beq.b fabs_inf +fabs_zero: + mov.b &z_bmask,FPSR_CC(%a6) # set 'Z' ccode bit + rts +fabs_inf: + mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit + rts + +######################################################################### +# XDEF **************************************************************** # +# fcmp(): fp compare op routine # +# # +# XREF **************************************************************** # +# res_qnan() - return QNAN result # +# res_snan() - return SNAN result # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# a1 = pointer to extended precision destination operand # +# d0 = round prec/mode # +# # +# OUTPUT ************************************************************** # +# None # +# # +# ALGORITHM *********************************************************** # +# Handle NANs and denorms as special cases. For everything else, # +# just use the actual fcmp instruction to produce the correct condition # +# codes. # +# # +######################################################################### + + global fcmp +fcmp: + clr.w %d1 + mov.b DTAG(%a6),%d1 + lsl.b &0x3,%d1 + or.b STAG(%a6),%d1 + bne.b fcmp_not_norm # optimize on non-norm input + +# +# COMPARE FP OPs : NORMs, ZEROs, INFs, and "corrected" DENORMs +# +fcmp_norm: + fmovm.x DST(%a1),&0x80 # load dst op + + fcmp.x %fp0,SRC(%a0) # do compare + + fmov.l %fpsr,%d0 # save FPSR + rol.l &0x8,%d0 # extract ccode bits + mov.b %d0,FPSR_CC(%a6) # set ccode bits(no exc bits are set) + + rts + +# +# fcmp: inputs are not both normalized; what are they? +# +fcmp_not_norm: + mov.w (tbl_fcmp_op.b,%pc,%d1.w*2),%d1 + jmp (tbl_fcmp_op.b,%pc,%d1.w*1) + + swbeg &48 +tbl_fcmp_op: + short fcmp_norm - tbl_fcmp_op # NORM - NORM + short fcmp_norm - tbl_fcmp_op # NORM - ZERO + short fcmp_norm - tbl_fcmp_op # NORM - INF + short fcmp_res_qnan - tbl_fcmp_op # NORM - QNAN + short fcmp_nrm_dnrm - tbl_fcmp_op # NORM - DENORM + short fcmp_res_snan - tbl_fcmp_op # NORM - SNAN + short tbl_fcmp_op - tbl_fcmp_op # + short tbl_fcmp_op - tbl_fcmp_op # + + short fcmp_norm - tbl_fcmp_op # ZERO - NORM + short fcmp_norm - tbl_fcmp_op # ZERO - ZERO + short fcmp_norm - tbl_fcmp_op # ZERO - INF + short fcmp_res_qnan - tbl_fcmp_op # ZERO - QNAN + short fcmp_dnrm_s - tbl_fcmp_op # ZERO - DENORM + short fcmp_res_snan - tbl_fcmp_op # ZERO - SNAN + short tbl_fcmp_op - tbl_fcmp_op # + short tbl_fcmp_op - tbl_fcmp_op # + + short fcmp_norm - tbl_fcmp_op # INF - NORM + short fcmp_norm - tbl_fcmp_op # INF - ZERO + short fcmp_norm - tbl_fcmp_op # INF - INF + short fcmp_res_qnan - tbl_fcmp_op # INF - QNAN + short fcmp_dnrm_s - tbl_fcmp_op # INF - DENORM + short fcmp_res_snan - tbl_fcmp_op # INF - SNAN + short tbl_fcmp_op - tbl_fcmp_op # + short tbl_fcmp_op - tbl_fcmp_op # + + short fcmp_res_qnan - tbl_fcmp_op # QNAN - NORM + short fcmp_res_qnan - tbl_fcmp_op # QNAN - ZERO + short fcmp_res_qnan - tbl_fcmp_op # QNAN - INF + short fcmp_res_qnan - tbl_fcmp_op # QNAN - QNAN + short fcmp_res_qnan - tbl_fcmp_op # QNAN - DENORM + short fcmp_res_snan - tbl_fcmp_op # QNAN - SNAN + short tbl_fcmp_op - tbl_fcmp_op # + short tbl_fcmp_op - tbl_fcmp_op # + + short fcmp_dnrm_nrm - tbl_fcmp_op # DENORM - NORM + short fcmp_dnrm_d - tbl_fcmp_op # DENORM - ZERO + short fcmp_dnrm_d - tbl_fcmp_op # DENORM - INF + short fcmp_res_qnan - tbl_fcmp_op # DENORM - QNAN + short fcmp_dnrm_sd - tbl_fcmp_op # DENORM - DENORM + short fcmp_res_snan - tbl_fcmp_op # DENORM - SNAN + short tbl_fcmp_op - tbl_fcmp_op # + short tbl_fcmp_op - tbl_fcmp_op # + + short fcmp_res_snan - tbl_fcmp_op # SNAN - NORM + short fcmp_res_snan - tbl_fcmp_op # SNAN - ZERO + short fcmp_res_snan - tbl_fcmp_op # SNAN - INF + short fcmp_res_snan - tbl_fcmp_op # SNAN - QNAN + short fcmp_res_snan - tbl_fcmp_op # SNAN - DENORM + short fcmp_res_snan - tbl_fcmp_op # SNAN - SNAN + short tbl_fcmp_op - tbl_fcmp_op # + short tbl_fcmp_op - tbl_fcmp_op # + +# unlike all other functions for QNAN and SNAN, fcmp does NOT set the +# 'N' bit for a negative QNAN or SNAN input so we must squelch it here. +fcmp_res_qnan: + bsr.l res_qnan + andi.b &0xf7,FPSR_CC(%a6) + rts +fcmp_res_snan: + bsr.l res_snan + andi.b &0xf7,FPSR_CC(%a6) + rts + +# +# DENORMs are a little more difficult. +# If you have a 2 DENORMs, then you can just force the j-bit to a one +# and use the fcmp_norm routine. +# If you have a DENORM and an INF or ZERO, just force the DENORM's j-bit to a one +# and use the fcmp_norm routine. +# If you have a DENORM and a NORM with opposite signs, then use fcmp_norm, also. +# But with a DENORM and a NORM of the same sign, the neg bit is set if the +# (1) signs are (+) and the DENORM is the dst or +# (2) signs are (-) and the DENORM is the src +# + +fcmp_dnrm_s: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),%d0 + bset &31,%d0 # DENORM src; make into small norm + mov.l %d0,FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + lea FP_SCR0(%a6),%a0 + bra.w fcmp_norm + +fcmp_dnrm_d: + mov.l DST_EX(%a1),FP_SCR0_EX(%a6) + mov.l DST_HI(%a1),%d0 + bset &31,%d0 # DENORM src; make into small norm + mov.l %d0,FP_SCR0_HI(%a6) + mov.l DST_LO(%a1),FP_SCR0_LO(%a6) + lea FP_SCR0(%a6),%a1 + bra.w fcmp_norm + +fcmp_dnrm_sd: + mov.w DST_EX(%a1),FP_SCR1_EX(%a6) + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l DST_HI(%a1),%d0 + bset &31,%d0 # DENORM dst; make into small norm + mov.l %d0,FP_SCR1_HI(%a6) + mov.l SRC_HI(%a0),%d0 + bset &31,%d0 # DENORM dst; make into small norm + mov.l %d0,FP_SCR0_HI(%a6) + mov.l DST_LO(%a1),FP_SCR1_LO(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + lea FP_SCR1(%a6),%a1 + lea FP_SCR0(%a6),%a0 + bra.w fcmp_norm + +fcmp_nrm_dnrm: + mov.b SRC_EX(%a0),%d0 # determine if like signs + mov.b DST_EX(%a1),%d1 + eor.b %d0,%d1 + bmi.w fcmp_dnrm_s + +# signs are the same, so must determine the answer ourselves. + tst.b %d0 # is src op negative? + bmi.b fcmp_nrm_dnrm_m # yes + rts +fcmp_nrm_dnrm_m: + mov.b &neg_bmask,FPSR_CC(%a6) # set 'Z' ccode bit + rts + +fcmp_dnrm_nrm: + mov.b SRC_EX(%a0),%d0 # determine if like signs + mov.b DST_EX(%a1),%d1 + eor.b %d0,%d1 + bmi.w fcmp_dnrm_d + +# signs are the same, so must determine the answer ourselves. + tst.b %d0 # is src op negative? + bpl.b fcmp_dnrm_nrm_m # no + rts +fcmp_dnrm_nrm_m: + mov.b &neg_bmask,FPSR_CC(%a6) # set 'Z' ccode bit + rts + +######################################################################### +# XDEF **************************************************************** # +# fsglmul(): emulates the fsglmul instruction # +# # +# XREF **************************************************************** # +# scale_to_zero_src() - scale src exponent to zero # +# scale_to_zero_dst() - scale dst exponent to zero # +# unf_res4() - return default underflow result for sglop # +# ovf_res() - return default overflow result # +# res_qnan() - return QNAN result # +# res_snan() - return SNAN result # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# a1 = pointer to extended precision destination operand # +# d0 rnd prec,mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, infinities, and zeroes as special cases. Divide # +# norms/denorms into ext/sgl/dbl precision. # +# For norms/denorms, scale the exponents such that a multiply # +# instruction won't cause an exception. Use the regular fsglmul to # +# compute a result. Check if the regular operands would have taken # +# an exception. If so, return the default overflow/underflow result # +# and return the EXOP if exceptions are enabled. Else, scale the # +# result operand to the proper exponent. # +# # +######################################################################### + + global fsglmul +fsglmul: + mov.l %d0,L_SCR3(%a6) # store rnd info + + clr.w %d1 + mov.b DTAG(%a6),%d1 + lsl.b &0x3,%d1 + or.b STAG(%a6),%d1 + + bne.w fsglmul_not_norm # optimize on non-norm input + +fsglmul_norm: + mov.w DST_EX(%a1),FP_SCR1_EX(%a6) + mov.l DST_HI(%a1),FP_SCR1_HI(%a6) + mov.l DST_LO(%a1),FP_SCR1_LO(%a6) + + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + + bsr.l scale_to_zero_src # scale exponent + mov.l %d0,-(%sp) # save scale factor 1 + + bsr.l scale_to_zero_dst # scale dst exponent + + add.l (%sp)+,%d0 # SCALE_FACTOR = scale1 + scale2 + + cmpi.l %d0,&0x3fff-0x7ffe # would result ovfl? + beq.w fsglmul_may_ovfl # result may rnd to overflow + blt.w fsglmul_ovfl # result will overflow + + cmpi.l %d0,&0x3fff+0x0001 # would result unfl? + beq.w fsglmul_may_unfl # result may rnd to no unfl + bgt.w fsglmul_unfl # result will underflow + +fsglmul_normal: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fsglmul_normal_exit: + fmovm.x &0x80,FP_SCR0(%a6) # store out result + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 + rts + +fsglmul_ovfl: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fsglmul_ovfl_tst: + +# save setting this until now because this is where fsglmul_may_ovfl may jump in + or.l &ovfl_inx_mask, USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fsglmul_ovfl_ena # yes + +fsglmul_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative? + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass prec:rnd + andi.b &0x30,%d0 # force prec = ext + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF,N if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + rts + +fsglmul_ovfl_ena: + fmovm.x &0x80,FP_SCR0(%a6) # move result to stack + + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + sub.l %d0,%d1 # add scale factor + subi.l &0x6000,%d1 # subtract bias + andi.w &0x7fff,%d1 + andi.w &0x8000,%d2 # keep old sign + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.b fsglmul_ovfl_dis + +fsglmul_may_ovfl: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fabs.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x2 # is |result| >= 2.b? + fbge.w fsglmul_ovfl_tst # yes; overflow has occurred + +# no, it didn't overflow; we have correct result + bra.w fsglmul_normal_exit + +fsglmul_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l &rz_mode*0x10,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fsglmul_unfl_ena # yes + +fsglmul_unfl_dis: + fmovm.x &0x80,FP_SCR0(%a6) # store out result + + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res4 # calculate default result + or.b %d0,FPSR_CC(%a6) # 'Z' bit may have been set + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + rts + +# +# UNFL is enabled. +# +fsglmul_unfl_ena: + fmovm.x FP_SCR1(%a6),&0x40 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsglmul.x FP_SCR0(%a6),%fp1 # execute sgl multiply + + fmov.l &0x0,%fpcr # clear FPCR + + fmovm.x &0x40,FP_SCR0(%a6) # save result to stack + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + addi.l &0x6000,%d1 # add bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.w fsglmul_unfl_dis + +fsglmul_may_unfl: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fabs.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x2 # is |result| > 2.b? + fbgt.w fsglmul_normal_exit # no; no underflow occurred + fblt.w fsglmul_unfl # yes; underflow occurred + +# +# we still don't know if underflow occurred. result is ~ equal to 2. but, +# we don't know if the result was an underflow that rounded up to a 2 or +# a normalized number that rounded down to a 2. so, redo the entire operation +# using RZ as the rounding mode to see what the pre-rounded result is. +# this case should be relatively rare. +# + fmovm.x FP_SCR1(%a6),&0x40 # load dst op into fp1 + + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # keep rnd prec + ori.b &rz_mode*0x10,%d1 # insert RZ + + fmov.l %d1,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsglmul.x FP_SCR0(%a6),%fp1 # execute sgl multiply + + fmov.l &0x0,%fpcr # clear FPCR + fabs.x %fp1 # make absolute value + fcmp.b %fp1,&0x2 # is |result| < 2.b? + fbge.w fsglmul_normal_exit # no; no underflow occurred + bra.w fsglmul_unfl # yes, underflow occurred + +############################################################################## + +# +# Single Precision Multiply: inputs are not both normalized; what are they? +# +fsglmul_not_norm: + mov.w (tbl_fsglmul_op.b,%pc,%d1.w*2),%d1 + jmp (tbl_fsglmul_op.b,%pc,%d1.w*1) + + swbeg &48 +tbl_fsglmul_op: + short fsglmul_norm - tbl_fsglmul_op # NORM x NORM + short fsglmul_zero - tbl_fsglmul_op # NORM x ZERO + short fsglmul_inf_src - tbl_fsglmul_op # NORM x INF + short fsglmul_res_qnan - tbl_fsglmul_op # NORM x QNAN + short fsglmul_norm - tbl_fsglmul_op # NORM x DENORM + short fsglmul_res_snan - tbl_fsglmul_op # NORM x SNAN + short tbl_fsglmul_op - tbl_fsglmul_op # + short tbl_fsglmul_op - tbl_fsglmul_op # + + short fsglmul_zero - tbl_fsglmul_op # ZERO x NORM + short fsglmul_zero - tbl_fsglmul_op # ZERO x ZERO + short fsglmul_res_operr - tbl_fsglmul_op # ZERO x INF + short fsglmul_res_qnan - tbl_fsglmul_op # ZERO x QNAN + short fsglmul_zero - tbl_fsglmul_op # ZERO x DENORM + short fsglmul_res_snan - tbl_fsglmul_op # ZERO x SNAN + short tbl_fsglmul_op - tbl_fsglmul_op # + short tbl_fsglmul_op - tbl_fsglmul_op # + + short fsglmul_inf_dst - tbl_fsglmul_op # INF x NORM + short fsglmul_res_operr - tbl_fsglmul_op # INF x ZERO + short fsglmul_inf_dst - tbl_fsglmul_op # INF x INF + short fsglmul_res_qnan - tbl_fsglmul_op # INF x QNAN + short fsglmul_inf_dst - tbl_fsglmul_op # INF x DENORM + short fsglmul_res_snan - tbl_fsglmul_op # INF x SNAN + short tbl_fsglmul_op - tbl_fsglmul_op # + short tbl_fsglmul_op - tbl_fsglmul_op # + + short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x NORM + short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x ZERO + short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x INF + short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x QNAN + short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x DENORM + short fsglmul_res_snan - tbl_fsglmul_op # QNAN x SNAN + short tbl_fsglmul_op - tbl_fsglmul_op # + short tbl_fsglmul_op - tbl_fsglmul_op # + + short fsglmul_norm - tbl_fsglmul_op # NORM x NORM + short fsglmul_zero - tbl_fsglmul_op # NORM x ZERO + short fsglmul_inf_src - tbl_fsglmul_op # NORM x INF + short fsglmul_res_qnan - tbl_fsglmul_op # NORM x QNAN + short fsglmul_norm - tbl_fsglmul_op # NORM x DENORM + short fsglmul_res_snan - tbl_fsglmul_op # NORM x SNAN + short tbl_fsglmul_op - tbl_fsglmul_op # + short tbl_fsglmul_op - tbl_fsglmul_op # + + short fsglmul_res_snan - tbl_fsglmul_op # SNAN x NORM + short fsglmul_res_snan - tbl_fsglmul_op # SNAN x ZERO + short fsglmul_res_snan - tbl_fsglmul_op # SNAN x INF + short fsglmul_res_snan - tbl_fsglmul_op # SNAN x QNAN + short fsglmul_res_snan - tbl_fsglmul_op # SNAN x DENORM + short fsglmul_res_snan - tbl_fsglmul_op # SNAN x SNAN + short tbl_fsglmul_op - tbl_fsglmul_op # + short tbl_fsglmul_op - tbl_fsglmul_op # + +fsglmul_res_operr: + bra.l res_operr +fsglmul_res_snan: + bra.l res_snan +fsglmul_res_qnan: + bra.l res_qnan +fsglmul_zero: + bra.l fmul_zero +fsglmul_inf_src: + bra.l fmul_inf_src +fsglmul_inf_dst: + bra.l fmul_inf_dst + +######################################################################### +# XDEF **************************************************************** # +# fsgldiv(): emulates the fsgldiv instruction # +# # +# XREF **************************************************************** # +# scale_to_zero_src() - scale src exponent to zero # +# scale_to_zero_dst() - scale dst exponent to zero # +# unf_res4() - return default underflow result for sglop # +# ovf_res() - return default overflow result # +# res_qnan() - return QNAN result # +# res_snan() - return SNAN result # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# a1 = pointer to extended precision destination operand # +# d0 rnd prec,mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, infinities, and zeroes as special cases. Divide # +# norms/denorms into ext/sgl/dbl precision. # +# For norms/denorms, scale the exponents such that a divide # +# instruction won't cause an exception. Use the regular fsgldiv to # +# compute a result. Check if the regular operands would have taken # +# an exception. If so, return the default overflow/underflow result # +# and return the EXOP if exceptions are enabled. Else, scale the # +# result operand to the proper exponent. # +# # +######################################################################### + + global fsgldiv +fsgldiv: + mov.l %d0,L_SCR3(%a6) # store rnd info + + clr.w %d1 + mov.b DTAG(%a6),%d1 + lsl.b &0x3,%d1 + or.b STAG(%a6),%d1 # combine src tags + + bne.w fsgldiv_not_norm # optimize on non-norm input + +# +# DIVIDE: NORMs and DENORMs ONLY! +# +fsgldiv_norm: + mov.w DST_EX(%a1),FP_SCR1_EX(%a6) + mov.l DST_HI(%a1),FP_SCR1_HI(%a6) + mov.l DST_LO(%a1),FP_SCR1_LO(%a6) + + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + + bsr.l scale_to_zero_src # calculate scale factor 1 + mov.l %d0,-(%sp) # save scale factor 1 + + bsr.l scale_to_zero_dst # calculate scale factor 2 + + neg.l (%sp) # S.F. = scale1 - scale2 + add.l %d0,(%sp) + + mov.w 2+L_SCR3(%a6),%d1 # fetch precision,mode + lsr.b &0x6,%d1 + mov.l (%sp)+,%d0 + cmpi.l %d0,&0x3fff-0x7ffe + ble.w fsgldiv_may_ovfl + + cmpi.l %d0,&0x3fff-0x0000 # will result underflow? + beq.w fsgldiv_may_unfl # maybe + bgt.w fsgldiv_unfl # yes; go handle underflow + +fsgldiv_normal: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # save FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsgldiv.x FP_SCR0(%a6),%fp0 # perform sgl divide + + fmov.l %fpsr,%d1 # save FPSR + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fsgldiv_normal_exit: + fmovm.x &0x80,FP_SCR0(%a6) # store result on stack + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 + rts + +fsgldiv_may_ovfl: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # set FPSR + + fsgldiv.x FP_SCR0(%a6),%fp0 # execute divide + + fmov.l %fpsr,%d1 + fmov.l &0x0,%fpcr + + or.l %d1,USER_FPSR(%a6) # save INEX,N + + fmovm.x &0x01,-(%sp) # save result to stack + mov.w (%sp),%d1 # fetch new exponent + add.l &0xc,%sp # clear result + andi.l &0x7fff,%d1 # strip sign + sub.l %d0,%d1 # add scale factor + cmp.l %d1,&0x7fff # did divide overflow? + blt.b fsgldiv_normal_exit + +fsgldiv_ovfl_tst: + or.w &ovfl_inx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fsgldiv_ovfl_ena # yes + +fsgldiv_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass prec:rnd + andi.b &0x30,%d0 # kill precision + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + rts + +fsgldiv_ovfl_ena: + fmovm.x &0x80,FP_SCR0(%a6) # move result to stack + + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + subi.l &0x6000,%d1 # subtract new bias + andi.w &0x7fff,%d1 # clear ms bit + or.w %d2,%d1 # concat old sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.b fsgldiv_ovfl_dis + +fsgldiv_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l &rz_mode*0x10,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsgldiv.x FP_SCR0(%a6),%fp0 # execute sgl divide + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fsgldiv_unfl_ena # yes + +fsgldiv_unfl_dis: + fmovm.x &0x80,FP_SCR0(%a6) # store out result + + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res4 # calculate default result + or.b %d0,FPSR_CC(%a6) # 'Z' bit may have been set + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + rts + +# +# UNFL is enabled. +# +fsgldiv_unfl_ena: + fmovm.x FP_SCR1(%a6),&0x40 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsgldiv.x FP_SCR0(%a6),%fp1 # execute sgl divide + + fmov.l &0x0,%fpcr # clear FPCR + + fmovm.x &0x40,FP_SCR0(%a6) # save result to stack + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + addi.l &0x6000,%d1 # add bias + andi.w &0x7fff,%d1 # clear top bit + or.w %d2,%d1 # concat old sign, new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.b fsgldiv_unfl_dis + +# +# the divide operation MAY underflow: +# +fsgldiv_may_unfl: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsgldiv.x FP_SCR0(%a6),%fp0 # execute sgl divide + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fabs.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x1 # is |result| > 1.b? + fbgt.w fsgldiv_normal_exit # no; no underflow occurred + fblt.w fsgldiv_unfl # yes; underflow occurred + +# +# we still don't know if underflow occurred. result is ~ equal to 1. but, +# we don't know if the result was an underflow that rounded up to a 1 +# or a normalized number that rounded down to a 1. so, redo the entire +# operation using RZ as the rounding mode to see what the pre-rounded +# result is. this case should be relatively rare. +# + fmovm.x FP_SCR1(%a6),&0x40 # load dst op into %fp1 + + clr.l %d1 # clear scratch register + ori.b &rz_mode*0x10,%d1 # force RZ rnd mode + + fmov.l %d1,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsgldiv.x FP_SCR0(%a6),%fp1 # execute sgl divide + + fmov.l &0x0,%fpcr # clear FPCR + fabs.x %fp1 # make absolute value + fcmp.b %fp1,&0x1 # is |result| < 1.b? + fbge.w fsgldiv_normal_exit # no; no underflow occurred + bra.w fsgldiv_unfl # yes; underflow occurred + +############################################################################ + +# +# Divide: inputs are not both normalized; what are they? +# +fsgldiv_not_norm: + mov.w (tbl_fsgldiv_op.b,%pc,%d1.w*2),%d1 + jmp (tbl_fsgldiv_op.b,%pc,%d1.w*1) + + swbeg &48 +tbl_fsgldiv_op: + short fsgldiv_norm - tbl_fsgldiv_op # NORM / NORM + short fsgldiv_inf_load - tbl_fsgldiv_op # NORM / ZERO + short fsgldiv_zero_load - tbl_fsgldiv_op # NORM / INF + short fsgldiv_res_qnan - tbl_fsgldiv_op # NORM / QNAN + short fsgldiv_norm - tbl_fsgldiv_op # NORM / DENORM + short fsgldiv_res_snan - tbl_fsgldiv_op # NORM / SNAN + short tbl_fsgldiv_op - tbl_fsgldiv_op # + short tbl_fsgldiv_op - tbl_fsgldiv_op # + + short fsgldiv_zero_load - tbl_fsgldiv_op # ZERO / NORM + short fsgldiv_res_operr - tbl_fsgldiv_op # ZERO / ZERO + short fsgldiv_zero_load - tbl_fsgldiv_op # ZERO / INF + short fsgldiv_res_qnan - tbl_fsgldiv_op # ZERO / QNAN + short fsgldiv_zero_load - tbl_fsgldiv_op # ZERO / DENORM + short fsgldiv_res_snan - tbl_fsgldiv_op # ZERO / SNAN + short tbl_fsgldiv_op - tbl_fsgldiv_op # + short tbl_fsgldiv_op - tbl_fsgldiv_op # + + short fsgldiv_inf_dst - tbl_fsgldiv_op # INF / NORM + short fsgldiv_inf_dst - tbl_fsgldiv_op # INF / ZERO + short fsgldiv_res_operr - tbl_fsgldiv_op # INF / INF + short fsgldiv_res_qnan - tbl_fsgldiv_op # INF / QNAN + short fsgldiv_inf_dst - tbl_fsgldiv_op # INF / DENORM + short fsgldiv_res_snan - tbl_fsgldiv_op # INF / SNAN + short tbl_fsgldiv_op - tbl_fsgldiv_op # + short tbl_fsgldiv_op - tbl_fsgldiv_op # + + short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / NORM + short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / ZERO + short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / INF + short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / QNAN + short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / DENORM + short fsgldiv_res_snan - tbl_fsgldiv_op # QNAN / SNAN + short tbl_fsgldiv_op - tbl_fsgldiv_op # + short tbl_fsgldiv_op - tbl_fsgldiv_op # + + short fsgldiv_norm - tbl_fsgldiv_op # DENORM / NORM + short fsgldiv_inf_load - tbl_fsgldiv_op # DENORM / ZERO + short fsgldiv_zero_load - tbl_fsgldiv_op # DENORM / INF + short fsgldiv_res_qnan - tbl_fsgldiv_op # DENORM / QNAN + short fsgldiv_norm - tbl_fsgldiv_op # DENORM / DENORM + short fsgldiv_res_snan - tbl_fsgldiv_op # DENORM / SNAN + short tbl_fsgldiv_op - tbl_fsgldiv_op # + short tbl_fsgldiv_op - tbl_fsgldiv_op # + + short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / NORM + short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / ZERO + short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / INF + short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / QNAN + short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / DENORM + short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / SNAN + short tbl_fsgldiv_op - tbl_fsgldiv_op # + short tbl_fsgldiv_op - tbl_fsgldiv_op # + +fsgldiv_res_qnan: + bra.l res_qnan +fsgldiv_res_snan: + bra.l res_snan +fsgldiv_res_operr: + bra.l res_operr +fsgldiv_inf_load: + bra.l fdiv_inf_load +fsgldiv_zero_load: + bra.l fdiv_zero_load +fsgldiv_inf_dst: + bra.l fdiv_inf_dst + +######################################################################### +# XDEF **************************************************************** # +# fadd(): emulates the fadd instruction # +# fsadd(): emulates the fadd instruction # +# fdadd(): emulates the fdadd instruction # +# # +# XREF **************************************************************** # +# addsub_scaler2() - scale the operands so they won't take exc # +# ovf_res() - return default overflow result # +# unf_res() - return default underflow result # +# res_qnan() - set QNAN result # +# res_snan() - set SNAN result # +# res_operr() - set OPERR result # +# scale_to_zero_src() - set src operand exponent equal to zero # +# scale_to_zero_dst() - set dst operand exponent equal to zero # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# a1 = pointer to extended precision destination operand # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, infinities, and zeroes as special cases. Divide # +# norms into extended, single, and double precision. # +# Do addition after scaling exponents such that exception won't # +# occur. Then, check result exponent to see if exception would have # +# occurred. If so, return default result and maybe EXOP. Else, insert # +# the correct result exponent and return. Set FPSR bits as appropriate. # +# # +######################################################################### + + global fsadd +fsadd: + andi.b &0x30,%d0 # clear rnd prec + ori.b &s_mode*0x10,%d0 # insert sgl prec + bra.b fadd + + global fdadd +fdadd: + andi.b &0x30,%d0 # clear rnd prec + ori.b &d_mode*0x10,%d0 # insert dbl prec + + global fadd +fadd: + mov.l %d0,L_SCR3(%a6) # store rnd info + + clr.w %d1 + mov.b DTAG(%a6),%d1 + lsl.b &0x3,%d1 + or.b STAG(%a6),%d1 # combine src tags + + bne.w fadd_not_norm # optimize on non-norm input + +# +# ADD: norms and denorms +# +fadd_norm: + bsr.l addsub_scaler2 # scale exponents + +fadd_zero_entry: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fadd.x FP_SCR0(%a6),%fp0 # execute add + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # fetch INEX2,N,Z + + or.l %d1,USER_FPSR(%a6) # save exc and ccode bits + + fbeq.w fadd_zero_exit # if result is zero, end now + + mov.l %d2,-(%sp) # save d2 + + fmovm.x &0x01,-(%sp) # save result to stack + + mov.w 2+L_SCR3(%a6),%d1 + lsr.b &0x6,%d1 + + mov.w (%sp),%d2 # fetch new sign, exp + andi.l &0x7fff,%d2 # strip sign + sub.l %d0,%d2 # add scale factor + + cmp.l %d2,(tbl_fadd_ovfl.b,%pc,%d1.w*4) # is it an overflow? + bge.b fadd_ovfl # yes + + cmp.l %d2,(tbl_fadd_unfl.b,%pc,%d1.w*4) # is it an underflow? + blt.w fadd_unfl # yes + beq.w fadd_may_unfl # maybe; go find out + +fadd_normal: + mov.w (%sp),%d1 + andi.w &0x8000,%d1 # keep sign + or.w %d2,%d1 # concat sign,new exp + mov.w %d1,(%sp) # insert new exponent + + fmovm.x (%sp)+,&0x80 # return result in fp0 + + mov.l (%sp)+,%d2 # restore d2 + rts + +fadd_zero_exit: +# fmov.s &0x00000000,%fp0 # return zero in fp0 + rts + +tbl_fadd_ovfl: + long 0x7fff # ext ovfl + long 0x407f # sgl ovfl + long 0x43ff # dbl ovfl + +tbl_fadd_unfl: + long 0x0000 # ext unfl + long 0x3f81 # sgl unfl + long 0x3c01 # dbl unfl + +fadd_ovfl: + or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fadd_ovfl_ena # yes + + add.l &0xc,%sp +fadd_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative? + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass prec:rnd + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF,N if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + mov.l (%sp)+,%d2 # restore d2 + rts + +fadd_ovfl_ena: + mov.b L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # is precision extended? + bne.b fadd_ovfl_ena_sd # no; prec = sgl or dbl + +fadd_ovfl_ena_cont: + mov.w (%sp),%d1 + andi.w &0x8000,%d1 # keep sign + subi.l &0x6000,%d2 # add extra bias + andi.w &0x7fff,%d2 + or.w %d2,%d1 # concat sign,new exp + mov.w %d1,(%sp) # insert new exponent + + fmovm.x (%sp)+,&0x40 # return EXOP in fp1 + bra.b fadd_ovfl_dis + +fadd_ovfl_ena_sd: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + mov.l L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # keep rnd mode + fmov.l %d1,%fpcr # set FPCR + + fadd.x FP_SCR0(%a6),%fp0 # execute add + + fmov.l &0x0,%fpcr # clear FPCR + + add.l &0xc,%sp + fmovm.x &0x01,-(%sp) + bra.b fadd_ovfl_ena_cont + +fadd_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + add.l &0xc,%sp + + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l &rz_mode*0x10,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fadd.x FP_SCR0(%a6),%fp0 # execute add + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # save status + + or.l %d1,USER_FPSR(%a6) # save INEX,N + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fadd_unfl_ena # yes + +fadd_unfl_dis: + fmovm.x &0x80,FP_SCR0(%a6) # store out result + + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # 'Z' bit may have been set + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + mov.l (%sp)+,%d2 # restore d2 + rts + +fadd_unfl_ena: + fmovm.x FP_SCR1(%a6),&0x40 # load dst op + + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # is precision extended? + bne.b fadd_unfl_ena_sd # no; sgl or dbl + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + +fadd_unfl_ena_cont: + fmov.l &0x0,%fpsr # clear FPSR + + fadd.x FP_SCR0(%a6),%fp1 # execute multiply + + fmov.l &0x0,%fpcr # clear FPCR + + fmovm.x &0x40,FP_SCR0(%a6) # save result to stack + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + addi.l &0x6000,%d1 # add new bias + andi.w &0x7fff,%d1 # clear top bit + or.w %d2,%d1 # concat sign,new exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.w fadd_unfl_dis + +fadd_unfl_ena_sd: + mov.l L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # use only rnd mode + fmov.l %d1,%fpcr # set FPCR + + bra.b fadd_unfl_ena_cont + +# +# result is equal to the smallest normalized number in the selected precision +# if the precision is extended, this result could not have come from an +# underflow that rounded up. +# +fadd_may_unfl: + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 + beq.w fadd_normal # yes; no underflow occurred + + mov.l 0x4(%sp),%d1 # extract hi(man) + cmpi.l %d1,&0x80000000 # is hi(man) = 0x80000000? + bne.w fadd_normal # no; no underflow occurred + + tst.l 0x8(%sp) # is lo(man) = 0x0? + bne.w fadd_normal # no; no underflow occurred + + btst &inex2_bit,FPSR_EXCEPT(%a6) # is INEX2 set? + beq.w fadd_normal # no; no underflow occurred + +# +# ok, so now the result has a exponent equal to the smallest normalized +# exponent for the selected precision. also, the mantissa is equal to +# 0x8000000000000000 and this mantissa is the result of rounding non-zero +# g,r,s. +# now, we must determine whether the pre-rounded result was an underflow +# rounded "up" or a normalized number rounded "down". +# so, we do this be re-executing the add using RZ as the rounding mode and +# seeing if the new result is smaller or equal to the current result. +# + fmovm.x FP_SCR1(%a6),&0x40 # load dst op into fp1 + + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # keep rnd prec + ori.b &rz_mode*0x10,%d1 # insert rnd mode + fmov.l %d1,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fadd.x FP_SCR0(%a6),%fp1 # execute add + + fmov.l &0x0,%fpcr # clear FPCR + + fabs.x %fp0 # compare absolute values + fabs.x %fp1 + fcmp.x %fp0,%fp1 # is first result > second? + + fbgt.w fadd_unfl # yes; it's an underflow + bra.w fadd_normal # no; it's not an underflow + +########################################################################## + +# +# Add: inputs are not both normalized; what are they? +# +fadd_not_norm: + mov.w (tbl_fadd_op.b,%pc,%d1.w*2),%d1 + jmp (tbl_fadd_op.b,%pc,%d1.w*1) + + swbeg &48 +tbl_fadd_op: + short fadd_norm - tbl_fadd_op # NORM + NORM + short fadd_zero_src - tbl_fadd_op # NORM + ZERO + short fadd_inf_src - tbl_fadd_op # NORM + INF + short fadd_res_qnan - tbl_fadd_op # NORM + QNAN + short fadd_norm - tbl_fadd_op # NORM + DENORM + short fadd_res_snan - tbl_fadd_op # NORM + SNAN + short tbl_fadd_op - tbl_fadd_op # + short tbl_fadd_op - tbl_fadd_op # + + short fadd_zero_dst - tbl_fadd_op # ZERO + NORM + short fadd_zero_2 - tbl_fadd_op # ZERO + ZERO + short fadd_inf_src - tbl_fadd_op # ZERO + INF + short fadd_res_qnan - tbl_fadd_op # NORM + QNAN + short fadd_zero_dst - tbl_fadd_op # ZERO + DENORM + short fadd_res_snan - tbl_fadd_op # NORM + SNAN + short tbl_fadd_op - tbl_fadd_op # + short tbl_fadd_op - tbl_fadd_op # + + short fadd_inf_dst - tbl_fadd_op # INF + NORM + short fadd_inf_dst - tbl_fadd_op # INF + ZERO + short fadd_inf_2 - tbl_fadd_op # INF + INF + short fadd_res_qnan - tbl_fadd_op # NORM + QNAN + short fadd_inf_dst - tbl_fadd_op # INF + DENORM + short fadd_res_snan - tbl_fadd_op # NORM + SNAN + short tbl_fadd_op - tbl_fadd_op # + short tbl_fadd_op - tbl_fadd_op # + + short fadd_res_qnan - tbl_fadd_op # QNAN + NORM + short fadd_res_qnan - tbl_fadd_op # QNAN + ZERO + short fadd_res_qnan - tbl_fadd_op # QNAN + INF + short fadd_res_qnan - tbl_fadd_op # QNAN + QNAN + short fadd_res_qnan - tbl_fadd_op # QNAN + DENORM + short fadd_res_snan - tbl_fadd_op # QNAN + SNAN + short tbl_fadd_op - tbl_fadd_op # + short tbl_fadd_op - tbl_fadd_op # + + short fadd_norm - tbl_fadd_op # DENORM + NORM + short fadd_zero_src - tbl_fadd_op # DENORM + ZERO + short fadd_inf_src - tbl_fadd_op # DENORM + INF + short fadd_res_qnan - tbl_fadd_op # NORM + QNAN + short fadd_norm - tbl_fadd_op # DENORM + DENORM + short fadd_res_snan - tbl_fadd_op # NORM + SNAN + short tbl_fadd_op - tbl_fadd_op # + short tbl_fadd_op - tbl_fadd_op # + + short fadd_res_snan - tbl_fadd_op # SNAN + NORM + short fadd_res_snan - tbl_fadd_op # SNAN + ZERO + short fadd_res_snan - tbl_fadd_op # SNAN + INF + short fadd_res_snan - tbl_fadd_op # SNAN + QNAN + short fadd_res_snan - tbl_fadd_op # SNAN + DENORM + short fadd_res_snan - tbl_fadd_op # SNAN + SNAN + short tbl_fadd_op - tbl_fadd_op # + short tbl_fadd_op - tbl_fadd_op # + +fadd_res_qnan: + bra.l res_qnan +fadd_res_snan: + bra.l res_snan + +# +# both operands are ZEROes +# +fadd_zero_2: + mov.b SRC_EX(%a0),%d0 # are the signs opposite + mov.b DST_EX(%a1),%d1 + eor.b %d0,%d1 + bmi.w fadd_zero_2_chk_rm # weed out (-ZERO)+(+ZERO) + +# the signs are the same. so determine whether they are positive or negative +# and return the appropriately signed zero. + tst.b %d0 # are ZEROes positive or negative? + bmi.b fadd_zero_rm # negative + fmov.s &0x00000000,%fp0 # return +ZERO + mov.b &z_bmask,FPSR_CC(%a6) # set Z + rts + +# +# the ZEROes have opposite signs: +# - Therefore, we return +ZERO if the rounding modes are RN,RZ, or RP. +# - -ZERO is returned in the case of RM. +# +fadd_zero_2_chk_rm: + mov.b 3+L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # extract rnd mode + cmpi.b %d1,&rm_mode*0x10 # is rnd mode == RM? + beq.b fadd_zero_rm # yes + fmov.s &0x00000000,%fp0 # return +ZERO + mov.b &z_bmask,FPSR_CC(%a6) # set Z + rts + +fadd_zero_rm: + fmov.s &0x80000000,%fp0 # return -ZERO + mov.b &neg_bmask+z_bmask,FPSR_CC(%a6) # set NEG/Z + rts + +# +# one operand is a ZERO and the other is a DENORM or NORM. scale +# the DENORM or NORM and jump to the regular fadd routine. +# +fadd_zero_dst: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + bsr.l scale_to_zero_src # scale the operand + clr.w FP_SCR1_EX(%a6) + clr.l FP_SCR1_HI(%a6) + clr.l FP_SCR1_LO(%a6) + bra.w fadd_zero_entry # go execute fadd + +fadd_zero_src: + mov.w DST_EX(%a1),FP_SCR1_EX(%a6) + mov.l DST_HI(%a1),FP_SCR1_HI(%a6) + mov.l DST_LO(%a1),FP_SCR1_LO(%a6) + bsr.l scale_to_zero_dst # scale the operand + clr.w FP_SCR0_EX(%a6) + clr.l FP_SCR0_HI(%a6) + clr.l FP_SCR0_LO(%a6) + bra.w fadd_zero_entry # go execute fadd + +# +# both operands are INFs. an OPERR will result if the INFs have +# different signs. else, an INF of the same sign is returned +# +fadd_inf_2: + mov.b SRC_EX(%a0),%d0 # exclusive or the signs + mov.b DST_EX(%a1),%d1 + eor.b %d1,%d0 + bmi.l res_operr # weed out (-INF)+(+INF) + +# ok, so it's not an OPERR. but, we do have to remember to return the +# src INF since that's where the 881/882 gets the j-bit from... + +# +# operands are INF and one of {ZERO, INF, DENORM, NORM} +# +fadd_inf_src: + fmovm.x SRC(%a0),&0x80 # return src INF + tst.b SRC_EX(%a0) # is INF positive? + bpl.b fadd_inf_done # yes; we're done + mov.b &neg_bmask+inf_bmask,FPSR_CC(%a6) # set INF/NEG + rts + +# +# operands are INF and one of {ZERO, INF, DENORM, NORM} +# +fadd_inf_dst: + fmovm.x DST(%a1),&0x80 # return dst INF + tst.b DST_EX(%a1) # is INF positive? + bpl.b fadd_inf_done # yes; we're done + mov.b &neg_bmask+inf_bmask,FPSR_CC(%a6) # set INF/NEG + rts + +fadd_inf_done: + mov.b &inf_bmask,FPSR_CC(%a6) # set INF + rts + +######################################################################### +# XDEF **************************************************************** # +# fsub(): emulates the fsub instruction # +# fssub(): emulates the fssub instruction # +# fdsub(): emulates the fdsub instruction # +# # +# XREF **************************************************************** # +# addsub_scaler2() - scale the operands so they won't take exc # +# ovf_res() - return default overflow result # +# unf_res() - return default underflow result # +# res_qnan() - set QNAN result # +# res_snan() - set SNAN result # +# res_operr() - set OPERR result # +# scale_to_zero_src() - set src operand exponent equal to zero # +# scale_to_zero_dst() - set dst operand exponent equal to zero # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# a1 = pointer to extended precision destination operand # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, infinities, and zeroes as special cases. Divide # +# norms into extended, single, and double precision. # +# Do subtraction after scaling exponents such that exception won't# +# occur. Then, check result exponent to see if exception would have # +# occurred. If so, return default result and maybe EXOP. Else, insert # +# the correct result exponent and return. Set FPSR bits as appropriate. # +# # +######################################################################### + + global fssub +fssub: + andi.b &0x30,%d0 # clear rnd prec + ori.b &s_mode*0x10,%d0 # insert sgl prec + bra.b fsub + + global fdsub +fdsub: + andi.b &0x30,%d0 # clear rnd prec + ori.b &d_mode*0x10,%d0 # insert dbl prec + + global fsub +fsub: + mov.l %d0,L_SCR3(%a6) # store rnd info + + clr.w %d1 + mov.b DTAG(%a6),%d1 + lsl.b &0x3,%d1 + or.b STAG(%a6),%d1 # combine src tags + + bne.w fsub_not_norm # optimize on non-norm input + +# +# SUB: norms and denorms +# +fsub_norm: + bsr.l addsub_scaler2 # scale exponents + +fsub_zero_entry: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fsub.x FP_SCR0(%a6),%fp0 # execute subtract + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # fetch INEX2, N, Z + + or.l %d1,USER_FPSR(%a6) # save exc and ccode bits + + fbeq.w fsub_zero_exit # if result zero, end now + + mov.l %d2,-(%sp) # save d2 + + fmovm.x &0x01,-(%sp) # save result to stack + + mov.w 2+L_SCR3(%a6),%d1 + lsr.b &0x6,%d1 + + mov.w (%sp),%d2 # fetch new exponent + andi.l &0x7fff,%d2 # strip sign + sub.l %d0,%d2 # add scale factor + + cmp.l %d2,(tbl_fsub_ovfl.b,%pc,%d1.w*4) # is it an overflow? + bge.b fsub_ovfl # yes + + cmp.l %d2,(tbl_fsub_unfl.b,%pc,%d1.w*4) # is it an underflow? + blt.w fsub_unfl # yes + beq.w fsub_may_unfl # maybe; go find out + +fsub_normal: + mov.w (%sp),%d1 + andi.w &0x8000,%d1 # keep sign + or.w %d2,%d1 # insert new exponent + mov.w %d1,(%sp) # insert new exponent + + fmovm.x (%sp)+,&0x80 # return result in fp0 + + mov.l (%sp)+,%d2 # restore d2 + rts + +fsub_zero_exit: +# fmov.s &0x00000000,%fp0 # return zero in fp0 + rts + +tbl_fsub_ovfl: + long 0x7fff # ext ovfl + long 0x407f # sgl ovfl + long 0x43ff # dbl ovfl + +tbl_fsub_unfl: + long 0x0000 # ext unfl + long 0x3f81 # sgl unfl + long 0x3c01 # dbl unfl + +fsub_ovfl: + or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fsub_ovfl_ena # yes + + add.l &0xc,%sp +fsub_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative? + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass prec:rnd + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF,N if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + mov.l (%sp)+,%d2 # restore d2 + rts + +fsub_ovfl_ena: + mov.b L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # is precision extended? + bne.b fsub_ovfl_ena_sd # no + +fsub_ovfl_ena_cont: + mov.w (%sp),%d1 # fetch {sgn,exp} + andi.w &0x8000,%d1 # keep sign + subi.l &0x6000,%d2 # subtract new bias + andi.w &0x7fff,%d2 # clear top bit + or.w %d2,%d1 # concat sign,exp + mov.w %d1,(%sp) # insert new exponent + + fmovm.x (%sp)+,&0x40 # return EXOP in fp1 + bra.b fsub_ovfl_dis + +fsub_ovfl_ena_sd: + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + mov.l L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # clear rnd prec + fmov.l %d1,%fpcr # set FPCR + + fsub.x FP_SCR0(%a6),%fp0 # execute subtract + + fmov.l &0x0,%fpcr # clear FPCR + + add.l &0xc,%sp + fmovm.x &0x01,-(%sp) + bra.b fsub_ovfl_ena_cont + +fsub_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + add.l &0xc,%sp + + fmovm.x FP_SCR1(%a6),&0x80 # load dst op + + fmov.l &rz_mode*0x10,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsub.x FP_SCR0(%a6),%fp0 # execute subtract + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # save status + + or.l %d1,USER_FPSR(%a6) + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fsub_unfl_ena # yes + +fsub_unfl_dis: + fmovm.x &0x80,FP_SCR0(%a6) # store out result + + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # 'Z' may have been set + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + mov.l (%sp)+,%d2 # restore d2 + rts + +fsub_unfl_ena: + fmovm.x FP_SCR1(%a6),&0x40 + + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # is precision extended? + bne.b fsub_unfl_ena_sd # no + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + +fsub_unfl_ena_cont: + fmov.l &0x0,%fpsr # clear FPSR + + fsub.x FP_SCR0(%a6),%fp1 # execute subtract + + fmov.l &0x0,%fpcr # clear FPCR + + fmovm.x &0x40,FP_SCR0(%a6) # store result to stack + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + addi.l &0x6000,%d1 # subtract new bias + andi.w &0x7fff,%d1 # clear top bit + or.w %d2,%d1 # concat sgn,exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + bra.w fsub_unfl_dis + +fsub_unfl_ena_sd: + mov.l L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # clear rnd prec + fmov.l %d1,%fpcr # set FPCR + + bra.b fsub_unfl_ena_cont + +# +# result is equal to the smallest normalized number in the selected precision +# if the precision is extended, this result could not have come from an +# underflow that rounded up. +# +fsub_may_unfl: + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # fetch rnd prec + beq.w fsub_normal # yes; no underflow occurred + + mov.l 0x4(%sp),%d1 + cmpi.l %d1,&0x80000000 # is hi(man) = 0x80000000? + bne.w fsub_normal # no; no underflow occurred + + tst.l 0x8(%sp) # is lo(man) = 0x0? + bne.w fsub_normal # no; no underflow occurred + + btst &inex2_bit,FPSR_EXCEPT(%a6) # is INEX2 set? + beq.w fsub_normal # no; no underflow occurred + +# +# ok, so now the result has a exponent equal to the smallest normalized +# exponent for the selected precision. also, the mantissa is equal to +# 0x8000000000000000 and this mantissa is the result of rounding non-zero +# g,r,s. +# now, we must determine whether the pre-rounded result was an underflow +# rounded "up" or a normalized number rounded "down". +# so, we do this be re-executing the add using RZ as the rounding mode and +# seeing if the new result is smaller or equal to the current result. +# + fmovm.x FP_SCR1(%a6),&0x40 # load dst op into fp1 + + mov.l L_SCR3(%a6),%d1 + andi.b &0xc0,%d1 # keep rnd prec + ori.b &rz_mode*0x10,%d1 # insert rnd mode + fmov.l %d1,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsub.x FP_SCR0(%a6),%fp1 # execute subtract + + fmov.l &0x0,%fpcr # clear FPCR + + fabs.x %fp0 # compare absolute values + fabs.x %fp1 + fcmp.x %fp0,%fp1 # is first result > second? + + fbgt.w fsub_unfl # yes; it's an underflow + bra.w fsub_normal # no; it's not an underflow + +########################################################################## + +# +# Sub: inputs are not both normalized; what are they? +# +fsub_not_norm: + mov.w (tbl_fsub_op.b,%pc,%d1.w*2),%d1 + jmp (tbl_fsub_op.b,%pc,%d1.w*1) + + swbeg &48 +tbl_fsub_op: + short fsub_norm - tbl_fsub_op # NORM - NORM + short fsub_zero_src - tbl_fsub_op # NORM - ZERO + short fsub_inf_src - tbl_fsub_op # NORM - INF + short fsub_res_qnan - tbl_fsub_op # NORM - QNAN + short fsub_norm - tbl_fsub_op # NORM - DENORM + short fsub_res_snan - tbl_fsub_op # NORM - SNAN + short tbl_fsub_op - tbl_fsub_op # + short tbl_fsub_op - tbl_fsub_op # + + short fsub_zero_dst - tbl_fsub_op # ZERO - NORM + short fsub_zero_2 - tbl_fsub_op # ZERO - ZERO + short fsub_inf_src - tbl_fsub_op # ZERO - INF + short fsub_res_qnan - tbl_fsub_op # NORM - QNAN + short fsub_zero_dst - tbl_fsub_op # ZERO - DENORM + short fsub_res_snan - tbl_fsub_op # NORM - SNAN + short tbl_fsub_op - tbl_fsub_op # + short tbl_fsub_op - tbl_fsub_op # + + short fsub_inf_dst - tbl_fsub_op # INF - NORM + short fsub_inf_dst - tbl_fsub_op # INF - ZERO + short fsub_inf_2 - tbl_fsub_op # INF - INF + short fsub_res_qnan - tbl_fsub_op # NORM - QNAN + short fsub_inf_dst - tbl_fsub_op # INF - DENORM + short fsub_res_snan - tbl_fsub_op # NORM - SNAN + short tbl_fsub_op - tbl_fsub_op # + short tbl_fsub_op - tbl_fsub_op # + + short fsub_res_qnan - tbl_fsub_op # QNAN - NORM + short fsub_res_qnan - tbl_fsub_op # QNAN - ZERO + short fsub_res_qnan - tbl_fsub_op # QNAN - INF + short fsub_res_qnan - tbl_fsub_op # QNAN - QNAN + short fsub_res_qnan - tbl_fsub_op # QNAN - DENORM + short fsub_res_snan - tbl_fsub_op # QNAN - SNAN + short tbl_fsub_op - tbl_fsub_op # + short tbl_fsub_op - tbl_fsub_op # + + short fsub_norm - tbl_fsub_op # DENORM - NORM + short fsub_zero_src - tbl_fsub_op # DENORM - ZERO + short fsub_inf_src - tbl_fsub_op # DENORM - INF + short fsub_res_qnan - tbl_fsub_op # NORM - QNAN + short fsub_norm - tbl_fsub_op # DENORM - DENORM + short fsub_res_snan - tbl_fsub_op # NORM - SNAN + short tbl_fsub_op - tbl_fsub_op # + short tbl_fsub_op - tbl_fsub_op # + + short fsub_res_snan - tbl_fsub_op # SNAN - NORM + short fsub_res_snan - tbl_fsub_op # SNAN - ZERO + short fsub_res_snan - tbl_fsub_op # SNAN - INF + short fsub_res_snan - tbl_fsub_op # SNAN - QNAN + short fsub_res_snan - tbl_fsub_op # SNAN - DENORM + short fsub_res_snan - tbl_fsub_op # SNAN - SNAN + short tbl_fsub_op - tbl_fsub_op # + short tbl_fsub_op - tbl_fsub_op # + +fsub_res_qnan: + bra.l res_qnan +fsub_res_snan: + bra.l res_snan + +# +# both operands are ZEROes +# +fsub_zero_2: + mov.b SRC_EX(%a0),%d0 + mov.b DST_EX(%a1),%d1 + eor.b %d1,%d0 + bpl.b fsub_zero_2_chk_rm + +# the signs are opposite, so, return a ZERO w/ the sign of the dst ZERO + tst.b %d0 # is dst negative? + bmi.b fsub_zero_2_rm # yes + fmov.s &0x00000000,%fp0 # no; return +ZERO + mov.b &z_bmask,FPSR_CC(%a6) # set Z + rts + +# +# the ZEROes have the same signs: +# - Therefore, we return +ZERO if the rounding mode is RN,RZ, or RP +# - -ZERO is returned in the case of RM. +# +fsub_zero_2_chk_rm: + mov.b 3+L_SCR3(%a6),%d1 + andi.b &0x30,%d1 # extract rnd mode + cmpi.b %d1,&rm_mode*0x10 # is rnd mode = RM? + beq.b fsub_zero_2_rm # yes + fmov.s &0x00000000,%fp0 # no; return +ZERO + mov.b &z_bmask,FPSR_CC(%a6) # set Z + rts + +fsub_zero_2_rm: + fmov.s &0x80000000,%fp0 # return -ZERO + mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set Z/NEG + rts + +# +# one operand is a ZERO and the other is a DENORM or a NORM. +# scale the DENORM or NORM and jump to the regular fsub routine. +# +fsub_zero_dst: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + bsr.l scale_to_zero_src # scale the operand + clr.w FP_SCR1_EX(%a6) + clr.l FP_SCR1_HI(%a6) + clr.l FP_SCR1_LO(%a6) + bra.w fsub_zero_entry # go execute fsub + +fsub_zero_src: + mov.w DST_EX(%a1),FP_SCR1_EX(%a6) + mov.l DST_HI(%a1),FP_SCR1_HI(%a6) + mov.l DST_LO(%a1),FP_SCR1_LO(%a6) + bsr.l scale_to_zero_dst # scale the operand + clr.w FP_SCR0_EX(%a6) + clr.l FP_SCR0_HI(%a6) + clr.l FP_SCR0_LO(%a6) + bra.w fsub_zero_entry # go execute fsub + +# +# both operands are INFs. an OPERR will result if the INFs have the +# same signs. else, +# +fsub_inf_2: + mov.b SRC_EX(%a0),%d0 # exclusive or the signs + mov.b DST_EX(%a1),%d1 + eor.b %d1,%d0 + bpl.l res_operr # weed out (-INF)+(+INF) + +# ok, so it's not an OPERR. but we do have to remember to return +# the src INF since that's where the 881/882 gets the j-bit. + +fsub_inf_src: + fmovm.x SRC(%a0),&0x80 # return src INF + fneg.x %fp0 # invert sign + fbge.w fsub_inf_done # sign is now positive + mov.b &neg_bmask+inf_bmask,FPSR_CC(%a6) # set INF/NEG + rts + +fsub_inf_dst: + fmovm.x DST(%a1),&0x80 # return dst INF + tst.b DST_EX(%a1) # is INF negative? + bpl.b fsub_inf_done # no + mov.b &neg_bmask+inf_bmask,FPSR_CC(%a6) # set INF/NEG + rts + +fsub_inf_done: + mov.b &inf_bmask,FPSR_CC(%a6) # set INF + rts + +######################################################################### +# XDEF **************************************************************** # +# fsqrt(): emulates the fsqrt instruction # +# fssqrt(): emulates the fssqrt instruction # +# fdsqrt(): emulates the fdsqrt instruction # +# # +# XREF **************************************************************** # +# scale_sqrt() - scale the source operand # +# unf_res() - return default underflow result # +# ovf_res() - return default overflow result # +# res_qnan_1op() - return QNAN result # +# res_snan_1op() - return SNAN result # +# # +# INPUT *************************************************************** # +# a0 = pointer to extended precision source operand # +# d0 rnd prec,mode # +# # +# OUTPUT ************************************************************** # +# fp0 = result # +# fp1 = EXOP (if exception occurred) # +# # +# ALGORITHM *********************************************************** # +# Handle NANs, infinities, and zeroes as special cases. Divide # +# norms/denorms into ext/sgl/dbl precision. # +# For norms/denorms, scale the exponents such that a sqrt # +# instruction won't cause an exception. Use the regular fsqrt to # +# compute a result. Check if the regular operands would have taken # +# an exception. If so, return the default overflow/underflow result # +# and return the EXOP if exceptions are enabled. Else, scale the # +# result operand to the proper exponent. # +# # +######################################################################### + + global fssqrt +fssqrt: + andi.b &0x30,%d0 # clear rnd prec + ori.b &s_mode*0x10,%d0 # insert sgl precision + bra.b fsqrt + + global fdsqrt +fdsqrt: + andi.b &0x30,%d0 # clear rnd prec + ori.b &d_mode*0x10,%d0 # insert dbl precision + + global fsqrt +fsqrt: + mov.l %d0,L_SCR3(%a6) # store rnd info + clr.w %d1 + mov.b STAG(%a6),%d1 + bne.w fsqrt_not_norm # optimize on non-norm input + +# +# SQUARE ROOT: norms and denorms ONLY! +# +fsqrt_norm: + tst.b SRC_EX(%a0) # is operand negative? + bmi.l res_operr # yes + + andi.b &0xc0,%d0 # is precision extended? + bne.b fsqrt_not_ext # no; go handle sgl or dbl + + fmov.l L_SCR3(%a6),%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsqrt.x (%a0),%fp0 # execute square root + + fmov.l %fpsr,%d1 + or.l %d1,USER_FPSR(%a6) # set N,INEX + + rts + +fsqrt_denorm: + tst.b SRC_EX(%a0) # is operand negative? + bmi.l res_operr # yes + + andi.b &0xc0,%d0 # is precision extended? + bne.b fsqrt_not_ext # no; go handle sgl or dbl + + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + + bsr.l scale_sqrt # calculate scale factor + + bra.w fsqrt_sd_normal + +# +# operand is either single or double +# +fsqrt_not_ext: + cmpi.b %d0,&s_mode*0x10 # separate sgl/dbl prec + bne.w fsqrt_dbl + +# +# operand is to be rounded to single precision +# +fsqrt_sgl: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + + bsr.l scale_sqrt # calculate scale factor + + cmpi.l %d0,&0x3fff-0x3f81 # will move in underflow? + beq.w fsqrt_sd_may_unfl + bgt.w fsqrt_sd_unfl # yes; go handle underflow + cmpi.l %d0,&0x3fff-0x407f # will move in overflow? + beq.w fsqrt_sd_may_ovfl # maybe; go check + blt.w fsqrt_sd_ovfl # yes; go handle overflow + +# +# operand will NOT overflow or underflow when moved in to the fp reg file +# +fsqrt_sd_normal: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fsqrt.x FP_SCR0(%a6),%fp0 # perform absolute + + fmov.l %fpsr,%d1 # save FPSR + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fsqrt_sd_normal_exit: + mov.l %d2,-(%sp) # save d2 + fmovm.x &0x80,FP_SCR0(%a6) # store out result + mov.w FP_SCR0_EX(%a6),%d1 # load sgn,exp + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + sub.l %d0,%d1 # add scale factor + andi.w &0x8000,%d2 # keep old sign + or.w %d1,%d2 # concat old sign,new exp + mov.w %d2,FP_SCR0_EX(%a6) # insert new exponent + mov.l (%sp)+,%d2 # restore d2 + fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 + rts + +# +# operand is to be rounded to double precision +# +fsqrt_dbl: + mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) + mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) + mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) + + bsr.l scale_sqrt # calculate scale factor + + cmpi.l %d0,&0x3fff-0x3c01 # will move in underflow? + beq.w fsqrt_sd_may_unfl + bgt.b fsqrt_sd_unfl # yes; go handle underflow + cmpi.l %d0,&0x3fff-0x43ff # will move in overflow? + beq.w fsqrt_sd_may_ovfl # maybe; go check + blt.w fsqrt_sd_ovfl # yes; go handle overflow + bra.w fsqrt_sd_normal # no; ho handle normalized op + +# we're on the line here and the distinguising characteristic is whether +# the exponent is 3fff or 3ffe. if it's 3ffe, then it's a safe number +# elsewise fall through to underflow. +fsqrt_sd_may_unfl: + btst &0x0,1+FP_SCR0_EX(%a6) # is exponent 0x3fff? + bne.w fsqrt_sd_normal # yes, so no underflow + +# +# operand WILL underflow when moved in to the fp register file +# +fsqrt_sd_unfl: + bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit + + fmov.l &rz_mode*0x10,%fpcr # set FPCR + fmov.l &0x0,%fpsr # clear FPSR + + fsqrt.x FP_SCR0(%a6),%fp0 # execute square root + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +# if underflow or inexact is enabled, go calculate EXOP first. + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x0b,%d1 # is UNFL or INEX enabled? + bne.b fsqrt_sd_unfl_ena # yes + +fsqrt_sd_unfl_dis: + fmovm.x &0x80,FP_SCR0(%a6) # store out result + + lea FP_SCR0(%a6),%a0 # pass: result addr + mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode + bsr.l unf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set possible 'Z' ccode + fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 + rts + +# +# operand will underflow AND underflow is enabled. +# Therefore, we must return the result rounded to extended precision. +# +fsqrt_sd_unfl_ena: + mov.l FP_SCR0_HI(%a6),FP_SCR1_HI(%a6) + mov.l FP_SCR0_LO(%a6),FP_SCR1_LO(%a6) + mov.w FP_SCR0_EX(%a6),%d1 # load current exponent + + mov.l %d2,-(%sp) # save d2 + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # subtract scale factor + addi.l &0x6000,%d1 # add new bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 # concat new sign,new exp + mov.w %d1,FP_SCR1_EX(%a6) # insert new exp + fmovm.x FP_SCR1(%a6),&0x40 # return EXOP in fp1 + mov.l (%sp)+,%d2 # restore d2 + bra.b fsqrt_sd_unfl_dis + +# +# operand WILL overflow. +# +fsqrt_sd_ovfl: + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fsqrt.x FP_SCR0(%a6),%fp0 # perform square root + + fmov.l &0x0,%fpcr # clear FPCR + fmov.l %fpsr,%d1 # save FPSR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + +fsqrt_sd_ovfl_tst: + or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex + + mov.b FPCR_ENABLE(%a6),%d1 + andi.b &0x13,%d1 # is OVFL or INEX enabled? + bne.b fsqrt_sd_ovfl_ena # yes + +# +# OVFL is not enabled; therefore, we must create the default result by +# calling ovf_res(). +# +fsqrt_sd_ovfl_dis: + btst &neg_bit,FPSR_CC(%a6) # is result negative? + sne %d1 # set sign param accordingly + mov.l L_SCR3(%a6),%d0 # pass: prec,mode + bsr.l ovf_res # calculate default result + or.b %d0,FPSR_CC(%a6) # set INF,N if applicable + fmovm.x (%a0),&0x80 # return default result in fp0 + rts + +# +# OVFL is enabled. +# the INEX2 bit has already been updated by the round to the correct precision. +# now, round to extended(and don't alter the FPSR). +# +fsqrt_sd_ovfl_ena: + mov.l %d2,-(%sp) # save d2 + mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} + mov.l %d1,%d2 # make a copy + andi.l &0x7fff,%d1 # strip sign + andi.w &0x8000,%d2 # keep old sign + sub.l %d0,%d1 # add scale factor + subi.l &0x6000,%d1 # subtract bias + andi.w &0x7fff,%d1 + or.w %d2,%d1 # concat sign,exp + mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent + fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 + mov.l (%sp)+,%d2 # restore d2 + bra.b fsqrt_sd_ovfl_dis + +# +# the move in MAY underflow. so... +# +fsqrt_sd_may_ovfl: + btst &0x0,1+FP_SCR0_EX(%a6) # is exponent 0x3fff? + bne.w fsqrt_sd_ovfl # yes, so overflow + + fmov.l &0x0,%fpsr # clear FPSR + fmov.l L_SCR3(%a6),%fpcr # set FPCR + + fsqrt.x FP_SCR0(%a6),%fp0 # perform absolute + + fmov.l %fpsr,%d1 # save status + fmov.l &0x0,%fpcr # clear FPCR + + or.l %d1,USER_FPSR(%a6) # save INEX2,N + + fmov.x %fp0,%fp1 # make a copy of result + fcmp.b %fp1,&0x1 # is |result| >= 1.b? + fbge.w fsqrt_sd_ovfl_tst # yes; overflow has occurred + +# no, it didn't overflow; we have correct result + bra.w fsqrt_sd_normal_exit + +########################################################################## + +# +# input is not normalized; what is it? +# +fsqrt_not_norm: + cmpi.b %d1,&DENORM # weed out DENORM + beq.w fsqrt_denorm + cmpi.b %d1,&ZERO # weed out ZERO + beq.b fsqrt_zero + cmpi.b %d1,&INF # weed out INF + beq.b fsqrt_inf + cmpi.b %d1,&SNAN # weed out SNAN + beq.l res_snan_1op + bra.l res_qnan_1op + +# +# fsqrt(+0) = +0 +# fsqrt(-0) = -0 +# fsqrt(+INF) = +INF +# fsqrt(-INF) = OPERR +# +fsqrt_zero: + tst.b SRC_EX(%a0) # is ZERO positive or negative? + bmi.b fsqrt_zero_m # negative +fsqrt_zero_p: + fmov.s &0x00000000,%fp0 # return +ZERO + mov.b &z_bmask,FPSR_CC(%a6) # set 'Z' ccode bit + rts +fsqrt_zero_m: + fmov.s &0x80000000,%fp0 # return -ZERO + mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set 'Z','N' ccode bits + rts + +fsqrt_inf: + tst.b SRC_EX(%a0) # is INF positive or negative? + bmi.l res_operr # negative +fsqrt_inf_p: + fmovm.x SRC(%a0),&0x80 # return +INF in fp0 + mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit + rts + +######################################################################### +# XDEF **************************************************************** # +# fetch_dreg(): fetch register according to index in d1 # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# d1 = index of register to fetch from # +# # +# OUTPUT ************************************************************** # +# d0 = value of register fetched # +# # +# ALGORITHM *********************************************************** # +# According to the index value in d1 which can range from zero # +# to fifteen, load the corresponding register file value (where # +# address register indexes start at 8). D0/D1/A0/A1/A6/A7 are on the # +# stack. The rest should still be in their original places. # +# # +######################################################################### + +# this routine leaves d1 intact for subsequent store_dreg calls. + global fetch_dreg +fetch_dreg: + mov.w (tbl_fdreg.b,%pc,%d1.w*2),%d0 + jmp (tbl_fdreg.b,%pc,%d0.w*1) + +tbl_fdreg: + short fdreg0 - tbl_fdreg + short fdreg1 - tbl_fdreg + short fdreg2 - tbl_fdreg + short fdreg3 - tbl_fdreg + short fdreg4 - tbl_fdreg + short fdreg5 - tbl_fdreg + short fdreg6 - tbl_fdreg + short fdreg7 - tbl_fdreg + short fdreg8 - tbl_fdreg + short fdreg9 - tbl_fdreg + short fdrega - tbl_fdreg + short fdregb - tbl_fdreg + short fdregc - tbl_fdreg + short fdregd - tbl_fdreg + short fdrege - tbl_fdreg + short fdregf - tbl_fdreg + +fdreg0: + mov.l EXC_DREGS+0x0(%a6),%d0 + rts +fdreg1: + mov.l EXC_DREGS+0x4(%a6),%d0 + rts +fdreg2: + mov.l %d2,%d0 + rts +fdreg3: + mov.l %d3,%d0 + rts +fdreg4: + mov.l %d4,%d0 + rts +fdreg5: + mov.l %d5,%d0 + rts +fdreg6: + mov.l %d6,%d0 + rts +fdreg7: + mov.l %d7,%d0 + rts +fdreg8: + mov.l EXC_DREGS+0x8(%a6),%d0 + rts +fdreg9: + mov.l EXC_DREGS+0xc(%a6),%d0 + rts +fdrega: + mov.l %a2,%d0 + rts +fdregb: + mov.l %a3,%d0 + rts +fdregc: + mov.l %a4,%d0 + rts +fdregd: + mov.l %a5,%d0 + rts +fdrege: + mov.l (%a6),%d0 + rts +fdregf: + mov.l EXC_A7(%a6),%d0 + rts + +######################################################################### +# XDEF **************************************************************** # +# store_dreg_l(): store longword to data register specified by d1 # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# d0 = longowrd value to store # +# d1 = index of register to fetch from # +# # +# OUTPUT ************************************************************** # +# (data register is updated) # +# # +# ALGORITHM *********************************************************** # +# According to the index value in d1, store the longword value # +# in d0 to the corresponding data register. D0/D1 are on the stack # +# while the rest are in their initial places. # +# # +######################################################################### + + global store_dreg_l +store_dreg_l: + mov.w (tbl_sdregl.b,%pc,%d1.w*2),%d1 + jmp (tbl_sdregl.b,%pc,%d1.w*1) + +tbl_sdregl: + short sdregl0 - tbl_sdregl + short sdregl1 - tbl_sdregl + short sdregl2 - tbl_sdregl + short sdregl3 - tbl_sdregl + short sdregl4 - tbl_sdregl + short sdregl5 - tbl_sdregl + short sdregl6 - tbl_sdregl + short sdregl7 - tbl_sdregl + +sdregl0: + mov.l %d0,EXC_DREGS+0x0(%a6) + rts +sdregl1: + mov.l %d0,EXC_DREGS+0x4(%a6) + rts +sdregl2: + mov.l %d0,%d2 + rts +sdregl3: + mov.l %d0,%d3 + rts +sdregl4: + mov.l %d0,%d4 + rts +sdregl5: + mov.l %d0,%d5 + rts +sdregl6: + mov.l %d0,%d6 + rts +sdregl7: + mov.l %d0,%d7 + rts + +######################################################################### +# XDEF **************************************************************** # +# store_dreg_w(): store word to data register specified by d1 # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# d0 = word value to store # +# d1 = index of register to fetch from # +# # +# OUTPUT ************************************************************** # +# (data register is updated) # +# # +# ALGORITHM *********************************************************** # +# According to the index value in d1, store the word value # +# in d0 to the corresponding data register. D0/D1 are on the stack # +# while the rest are in their initial places. # +# # +######################################################################### + + global store_dreg_w +store_dreg_w: + mov.w (tbl_sdregw.b,%pc,%d1.w*2),%d1 + jmp (tbl_sdregw.b,%pc,%d1.w*1) + +tbl_sdregw: + short sdregw0 - tbl_sdregw + short sdregw1 - tbl_sdregw + short sdregw2 - tbl_sdregw + short sdregw3 - tbl_sdregw + short sdregw4 - tbl_sdregw + short sdregw5 - tbl_sdregw + short sdregw6 - tbl_sdregw + short sdregw7 - tbl_sdregw + +sdregw0: + mov.w %d0,2+EXC_DREGS+0x0(%a6) + rts +sdregw1: + mov.w %d0,2+EXC_DREGS+0x4(%a6) + rts +sdregw2: + mov.w %d0,%d2 + rts +sdregw3: + mov.w %d0,%d3 + rts +sdregw4: + mov.w %d0,%d4 + rts +sdregw5: + mov.w %d0,%d5 + rts +sdregw6: + mov.w %d0,%d6 + rts +sdregw7: + mov.w %d0,%d7 + rts + +######################################################################### +# XDEF **************************************************************** # +# store_dreg_b(): store byte to data register specified by d1 # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# d0 = byte value to store # +# d1 = index of register to fetch from # +# # +# OUTPUT ************************************************************** # +# (data register is updated) # +# # +# ALGORITHM *********************************************************** # +# According to the index value in d1, store the byte value # +# in d0 to the corresponding data register. D0/D1 are on the stack # +# while the rest are in their initial places. # +# # +######################################################################### + + global store_dreg_b +store_dreg_b: + mov.w (tbl_sdregb.b,%pc,%d1.w*2),%d1 + jmp (tbl_sdregb.b,%pc,%d1.w*1) + +tbl_sdregb: + short sdregb0 - tbl_sdregb + short sdregb1 - tbl_sdregb + short sdregb2 - tbl_sdregb + short sdregb3 - tbl_sdregb + short sdregb4 - tbl_sdregb + short sdregb5 - tbl_sdregb + short sdregb6 - tbl_sdregb + short sdregb7 - tbl_sdregb + +sdregb0: + mov.b %d0,3+EXC_DREGS+0x0(%a6) + rts +sdregb1: + mov.b %d0,3+EXC_DREGS+0x4(%a6) + rts +sdregb2: + mov.b %d0,%d2 + rts +sdregb3: + mov.b %d0,%d3 + rts +sdregb4: + mov.b %d0,%d4 + rts +sdregb5: + mov.b %d0,%d5 + rts +sdregb6: + mov.b %d0,%d6 + rts +sdregb7: + mov.b %d0,%d7 + rts + +######################################################################### +# XDEF **************************************************************** # +# inc_areg(): increment an address register by the value in d0 # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# d0 = amount to increment by # +# d1 = index of address register to increment # +# # +# OUTPUT ************************************************************** # +# (address register is updated) # +# # +# ALGORITHM *********************************************************** # +# Typically used for an instruction w/ a post-increment <ea>, # +# this routine adds the increment value in d0 to the address register # +# specified by d1. A0/A1/A6/A7 reside on the stack. The rest reside # +# in their original places. # +# For a7, if the increment amount is one, then we have to # +# increment by two. For any a7 update, set the mia7_flag so that if # +# an access error exception occurs later in emulation, this address # +# register update can be undone. # +# # +######################################################################### + + global inc_areg +inc_areg: + mov.w (tbl_iareg.b,%pc,%d1.w*2),%d1 + jmp (tbl_iareg.b,%pc,%d1.w*1) + +tbl_iareg: + short iareg0 - tbl_iareg + short iareg1 - tbl_iareg + short iareg2 - tbl_iareg + short iareg3 - tbl_iareg + short iareg4 - tbl_iareg + short iareg5 - tbl_iareg + short iareg6 - tbl_iareg + short iareg7 - tbl_iareg + +iareg0: add.l %d0,EXC_DREGS+0x8(%a6) + rts +iareg1: add.l %d0,EXC_DREGS+0xc(%a6) + rts +iareg2: add.l %d0,%a2 + rts +iareg3: add.l %d0,%a3 + rts +iareg4: add.l %d0,%a4 + rts +iareg5: add.l %d0,%a5 + rts +iareg6: add.l %d0,(%a6) + rts +iareg7: mov.b &mia7_flg,SPCOND_FLG(%a6) + cmpi.b %d0,&0x1 + beq.b iareg7b + add.l %d0,EXC_A7(%a6) + rts +iareg7b: + addq.l &0x2,EXC_A7(%a6) + rts + +######################################################################### +# XDEF **************************************************************** # +# dec_areg(): decrement an address register by the value in d0 # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# d0 = amount to decrement by # +# d1 = index of address register to decrement # +# # +# OUTPUT ************************************************************** # +# (address register is updated) # +# # +# ALGORITHM *********************************************************** # +# Typically used for an instruction w/ a pre-decrement <ea>, # +# this routine adds the decrement value in d0 to the address register # +# specified by d1. A0/A1/A6/A7 reside on the stack. The rest reside # +# in their original places. # +# For a7, if the decrement amount is one, then we have to # +# decrement by two. For any a7 update, set the mda7_flag so that if # +# an access error exception occurs later in emulation, this address # +# register update can be undone. # +# # +######################################################################### + + global dec_areg +dec_areg: + mov.w (tbl_dareg.b,%pc,%d1.w*2),%d1 + jmp (tbl_dareg.b,%pc,%d1.w*1) + +tbl_dareg: + short dareg0 - tbl_dareg + short dareg1 - tbl_dareg + short dareg2 - tbl_dareg + short dareg3 - tbl_dareg + short dareg4 - tbl_dareg + short dareg5 - tbl_dareg + short dareg6 - tbl_dareg + short dareg7 - tbl_dareg + +dareg0: sub.l %d0,EXC_DREGS+0x8(%a6) + rts +dareg1: sub.l %d0,EXC_DREGS+0xc(%a6) + rts +dareg2: sub.l %d0,%a2 + rts +dareg3: sub.l %d0,%a3 + rts +dareg4: sub.l %d0,%a4 + rts +dareg5: sub.l %d0,%a5 + rts +dareg6: sub.l %d0,(%a6) + rts +dareg7: mov.b &mda7_flg,SPCOND_FLG(%a6) + cmpi.b %d0,&0x1 + beq.b dareg7b + sub.l %d0,EXC_A7(%a6) + rts +dareg7b: + subq.l &0x2,EXC_A7(%a6) + rts + +############################################################################## + +######################################################################### +# XDEF **************************************************************** # +# load_fpn1(): load FP register value into FP_SRC(a6). # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# d0 = index of FP register to load # +# # +# OUTPUT ************************************************************** # +# FP_SRC(a6) = value loaded from FP register file # +# # +# ALGORITHM *********************************************************** # +# Using the index in d0, load FP_SRC(a6) with a number from the # +# FP register file. # +# # +######################################################################### + + global load_fpn1 +load_fpn1: + mov.w (tbl_load_fpn1.b,%pc,%d0.w*2), %d0 + jmp (tbl_load_fpn1.b,%pc,%d0.w*1) + +tbl_load_fpn1: + short load_fpn1_0 - tbl_load_fpn1 + short load_fpn1_1 - tbl_load_fpn1 + short load_fpn1_2 - tbl_load_fpn1 + short load_fpn1_3 - tbl_load_fpn1 + short load_fpn1_4 - tbl_load_fpn1 + short load_fpn1_5 - tbl_load_fpn1 + short load_fpn1_6 - tbl_load_fpn1 + short load_fpn1_7 - tbl_load_fpn1 + +load_fpn1_0: + mov.l 0+EXC_FP0(%a6), 0+FP_SRC(%a6) + mov.l 4+EXC_FP0(%a6), 4+FP_SRC(%a6) + mov.l 8+EXC_FP0(%a6), 8+FP_SRC(%a6) + lea FP_SRC(%a6), %a0 + rts +load_fpn1_1: + mov.l 0+EXC_FP1(%a6), 0+FP_SRC(%a6) + mov.l 4+EXC_FP1(%a6), 4+FP_SRC(%a6) + mov.l 8+EXC_FP1(%a6), 8+FP_SRC(%a6) + lea FP_SRC(%a6), %a0 + rts +load_fpn1_2: + fmovm.x &0x20, FP_SRC(%a6) + lea FP_SRC(%a6), %a0 + rts +load_fpn1_3: + fmovm.x &0x10, FP_SRC(%a6) + lea FP_SRC(%a6), %a0 + rts +load_fpn1_4: + fmovm.x &0x08, FP_SRC(%a6) + lea FP_SRC(%a6), %a0 + rts +load_fpn1_5: + fmovm.x &0x04, FP_SRC(%a6) + lea FP_SRC(%a6), %a0 + rts +load_fpn1_6: + fmovm.x &0x02, FP_SRC(%a6) + lea FP_SRC(%a6), %a0 + rts +load_fpn1_7: + fmovm.x &0x01, FP_SRC(%a6) + lea FP_SRC(%a6), %a0 + rts + +############################################################################# + +######################################################################### +# XDEF **************************************************************** # +# load_fpn2(): load FP register value into FP_DST(a6). # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# d0 = index of FP register to load # +# # +# OUTPUT ************************************************************** # +# FP_DST(a6) = value loaded from FP register file # +# # +# ALGORITHM *********************************************************** # +# Using the index in d0, load FP_DST(a6) with a number from the # +# FP register file. # +# # +######################################################################### + + global load_fpn2 +load_fpn2: + mov.w (tbl_load_fpn2.b,%pc,%d0.w*2), %d0 + jmp (tbl_load_fpn2.b,%pc,%d0.w*1) + +tbl_load_fpn2: + short load_fpn2_0 - tbl_load_fpn2 + short load_fpn2_1 - tbl_load_fpn2 + short load_fpn2_2 - tbl_load_fpn2 + short load_fpn2_3 - tbl_load_fpn2 + short load_fpn2_4 - tbl_load_fpn2 + short load_fpn2_5 - tbl_load_fpn2 + short load_fpn2_6 - tbl_load_fpn2 + short load_fpn2_7 - tbl_load_fpn2 + +load_fpn2_0: + mov.l 0+EXC_FP0(%a6), 0+FP_DST(%a6) + mov.l 4+EXC_FP0(%a6), 4+FP_DST(%a6) + mov.l 8+EXC_FP0(%a6), 8+FP_DST(%a6) + lea FP_DST(%a6), %a0 + rts +load_fpn2_1: + mov.l 0+EXC_FP1(%a6), 0+FP_DST(%a6) + mov.l 4+EXC_FP1(%a6), 4+FP_DST(%a6) + mov.l 8+EXC_FP1(%a6), 8+FP_DST(%a6) + lea FP_DST(%a6), %a0 + rts +load_fpn2_2: + fmovm.x &0x20, FP_DST(%a6) + lea FP_DST(%a6), %a0 + rts +load_fpn2_3: + fmovm.x &0x10, FP_DST(%a6) + lea FP_DST(%a6), %a0 + rts +load_fpn2_4: + fmovm.x &0x08, FP_DST(%a6) + lea FP_DST(%a6), %a0 + rts +load_fpn2_5: + fmovm.x &0x04, FP_DST(%a6) + lea FP_DST(%a6), %a0 + rts +load_fpn2_6: + fmovm.x &0x02, FP_DST(%a6) + lea FP_DST(%a6), %a0 + rts +load_fpn2_7: + fmovm.x &0x01, FP_DST(%a6) + lea FP_DST(%a6), %a0 + rts + +############################################################################# + +######################################################################### +# XDEF **************************************************************** # +# store_fpreg(): store an fp value to the fpreg designated d0. # +# # +# XREF **************************************************************** # +# None # +# # +# INPUT *************************************************************** # +# fp0 = extended precision value to store # +# d0 = index of floating-point register # +# # +# OUTPUT ************************************************************** # +# None # +# # +# ALGORITHM *********************************************************** # +# Store the value in fp0 to the FP register designated by the # +# value in d0. The FP number can be DENORM or SNAN so we have to be # +# careful that we don't take an exception here. # +# # +######################################################################### + + global store_fpreg +store_fpreg: + mov.w (tbl_store_fpreg.b,%pc,%d0.w*2), %d0 + jmp (tbl_store_fpreg.b,%pc,%d0.w*1) + +tbl_store_fpreg: + short store_fpreg_0 - tbl_store_fpreg + short store_fpreg_1 - tbl_store_fpreg + short store_fpreg_2 - tbl_store_fpreg + short store_fpreg_3 - tbl_store_fpreg + short store_fpreg_4 - tbl_store_fpreg + short store_fpreg_5 - tbl_store_fpreg + short store_fpreg_6 - tbl_store_fpreg + short store_fpreg_7 - tbl_store_fpreg + +store_fpreg_0: + fmovm.x &0x80, EXC_FP0(%a6) + rts +store_fpreg_1: + fmovm.x &0x80, EXC_FP1(%a6) + rts +store_fpreg_2: + fmovm.x &0x01, -(%sp) + fmovm.x (%sp)+, &0x20 + rts +store_fpreg_3: + fmovm.x &0x01, -(%sp) + fmovm.x (%sp)+, &0x10 + rts +store_fpreg_4: + fmovm.x &0x01, -(%sp) + fmovm.x (%sp)+, &0x08 + rts +store_fpreg_5: + fmovm.x &0x01, -(%sp) + fmovm.x (%sp)+, &0x04 + rts +store_fpreg_6: + fmovm.x &0x01, -(%sp) + fmovm.x (%sp)+, &0x02 + rts +store_fpreg_7: + fmovm.x &0x01, -(%sp) + fmovm.x (%sp)+, &0x01 + rts + +######################################################################### +# XDEF **************************************************************** # +# get_packed(): fetch a packed operand from memory and then # +# convert it to a floating-point binary number. # +# # +# XREF **************************************************************** # +# _dcalc_ea() - calculate the correct <ea> # +# _mem_read() - fetch the packed operand from memory # +# facc_in_x() - the fetch failed so jump to special exit code # +# decbin() - convert packed to binary extended precision # +# # +# INPUT *************************************************************** # +# None # +# # +# OUTPUT ************************************************************** # +# If no failure on _mem_read(): # +# FP_SRC(a6) = packed operand now as a binary FP number # +# # +# ALGORITHM *********************************************************** # +# Get the correct <ea> which is the value on the exception stack # +# frame w/ maybe a correction factor if the <ea> is -(an) or (an)+. # +# Then, fetch the operand from memory. If the fetch fails, exit # +# through facc_in_x(). # +# If the packed operand is a ZERO,NAN, or INF, convert it to # +# its binary representation here. Else, call decbin() which will # +# convert the packed value to an extended precision binary value. # +# # +######################################################################### + +# the stacked <ea> for packed is correct except for -(An). +# the base reg must be updated for both -(An) and (An)+. + global get_packed +get_packed: + mov.l &0xc,%d0 # packed is 12 bytes + bsr.l _dcalc_ea # fetch <ea>; correct An + + lea FP_SRC(%a6),%a1 # pass: ptr to super dst + mov.l &0xc,%d0 # pass: 12 bytes + bsr.l _dmem_read # read packed operand + + tst.l %d1 # did dfetch fail? + bne.l facc_in_x # yes + +# The packed operand is an INF or a NAN if the exponent field is all ones. + bfextu FP_SRC(%a6){&1:&15},%d0 # get exp + cmpi.w %d0,&0x7fff # INF or NAN? + bne.b gp_try_zero # no + rts # operand is an INF or NAN + +# The packed operand is a zero if the mantissa is all zero, else it's +# a normal packed op. +gp_try_zero: + mov.b 3+FP_SRC(%a6),%d0 # get byte 4 + andi.b &0x0f,%d0 # clear all but last nybble + bne.b gp_not_spec # not a zero + tst.l FP_SRC_HI(%a6) # is lw 2 zero? + bne.b gp_not_spec # not a zero + tst.l FP_SRC_LO(%a6) # is lw 3 zero? + bne.b gp_not_spec # not a zero + rts # operand is a ZERO +gp_not_spec: + lea FP_SRC(%a6),%a0 # pass: ptr to packed op + bsr.l decbin # convert to extended + fmovm.x &0x80,FP_SRC(%a6) # make this the srcop + rts + +######################################################################### +# decbin(): Converts normalized packed bcd value pointed to by register # +# a0 to extended-precision value in fp0. # +# # +# INPUT *************************************************************** # +# a0 = pointer to normalized packed bcd value # +# # +# OUTPUT ************************************************************** # +# fp0 = exact fp representation of the packed bcd value. # +# # +# ALGORITHM *********************************************************** # +# Expected is a normal bcd (i.e. non-exceptional; all inf, zero, # +# and NaN operands are dispatched without entering this routine) # +# value in 68881/882 format at location (a0). # +# # +# A1. Convert the bcd exponent to binary by successive adds and # +# muls. Set the sign according to SE. Subtract 16 to compensate # +# for the mantissa which is to be interpreted as 17 integer # +# digits, rather than 1 integer and 16 fraction digits. # +# Note: this operation can never overflow. # +# # +# A2. Convert the bcd mantissa to binary by successive # +# adds and muls in FP0. Set the sign according to SM. # +# The mantissa digits will be converted with the decimal point # +# assumed following the least-significant digit. # +# Note: this operation can never overflow. # +# # +# A3. Count the number of leading/trailing zeros in the # +# bcd string. If SE is positive, count the leading zeros; # +# if negative, count the trailing zeros. Set the adjusted # +# exponent equal to the exponent from A1 and the zero count # +# added if SM = 1 and subtracted if SM = 0. Scale the # +# mantissa the equivalent of forcing in the bcd value: # +# # +# SM = 0 a non-zero digit in the integer position # +# SM = 1 a non-zero digit in Mant0, lsd of the fraction # +# # +# this will insure that any value, regardless of its # +# representation (ex. 0.1E2, 1E1, 10E0, 100E-1), is converted # +# consistently. # +# # +# A4. Calculate the factor 10^exp in FP1 using a table of # +# 10^(2^n) values. To reduce the error in forming factors # +# greater than 10^27, a directed rounding scheme is used with # +# tables rounded to RN, RM, and RP, according to the table # +# in the comments of the pwrten section. # +# # +# A5. Form the final binary number by scaling the mantissa by # +# the exponent factor. This is done by multiplying the # +# mantissa in FP0 by the factor in FP1 if the adjusted # +# exponent sign is positive, and dividing FP0 by FP1 if # +# it is negative. # +# # +# Clean up and return. Check if the final mul or div was inexact. # +# If so, set INEX1 in USER_FPSR. # +# # +######################################################################### + +# +# PTENRN, PTENRM, and PTENRP are arrays of powers of 10 rounded +# to nearest, minus, and plus, respectively. The tables include +# 10**{1,2,4,8,16,32,64,128,256,512,1024,2048,4096}. No rounding +# is required until the power is greater than 27, however, all +# tables include the first 5 for ease of indexing. +# +RTABLE: + byte 0,0,0,0 + byte 2,3,2,3 + byte 2,3,3,2 + byte 3,2,2,3 + + set FNIBS,7 + set FSTRT,0 + + set ESTRT,4 + set EDIGITS,2 + + global decbin +decbin: + mov.l 0x0(%a0),FP_SCR0_EX(%a6) # make a copy of input + mov.l 0x4(%a0),FP_SCR0_HI(%a6) # so we don't alter it + mov.l 0x8(%a0),FP_SCR0_LO(%a6) + + lea FP_SCR0(%a6),%a0 + + movm.l &0x3c00,-(%sp) # save d2-d5 + fmovm.x &0x1,-(%sp) # save fp1 +# +# Calculate exponent: +# 1. Copy bcd value in memory for use as a working copy. +# 2. Calculate absolute value of exponent in d1 by mul and add. +# 3. Correct for exponent sign. +# 4. Subtract 16 to compensate for interpreting the mant as all integer digits. +# (i.e., all digits assumed left of the decimal point.) +# +# Register usage: +# +# calc_e: +# (*) d0: temp digit storage +# (*) d1: accumulator for binary exponent +# (*) d2: digit count +# (*) d3: offset pointer +# ( ) d4: first word of bcd +# ( ) a0: pointer to working bcd value +# ( ) a6: pointer to original bcd value +# (*) FP_SCR1: working copy of original bcd value +# (*) L_SCR1: copy of original exponent word +# +calc_e: + mov.l &EDIGITS,%d2 # # of nibbles (digits) in fraction part + mov.l &ESTRT,%d3 # counter to pick up digits + mov.l (%a0),%d4 # get first word of bcd + clr.l %d1 # zero d1 for accumulator +e_gd: + mulu.l &0xa,%d1 # mul partial product by one digit place + bfextu %d4{%d3:&4},%d0 # get the digit and zero extend into d0 + add.l %d0,%d1 # d1 = d1 + d0 + addq.b &4,%d3 # advance d3 to the next digit + dbf.w %d2,e_gd # if we have used all 3 digits, exit loop + btst &30,%d4 # get SE + beq.b e_pos # don't negate if pos + neg.l %d1 # negate before subtracting +e_pos: + sub.l &16,%d1 # sub to compensate for shift of mant + bge.b e_save # if still pos, do not neg + neg.l %d1 # now negative, make pos and set SE + or.l &0x40000000,%d4 # set SE in d4, + or.l &0x40000000,(%a0) # and in working bcd +e_save: + mov.l %d1,-(%sp) # save exp on stack +# +# +# Calculate mantissa: +# 1. Calculate absolute value of mantissa in fp0 by mul and add. +# 2. Correct for mantissa sign. +# (i.e., all digits assumed left of the decimal point.) +# +# Register usage: +# +# calc_m: +# (*) d0: temp digit storage +# (*) d1: lword counter +# (*) d2: digit count +# (*) d3: offset pointer +# ( ) d4: words 2 and 3 of bcd +# ( ) a0: pointer to working bcd value +# ( ) a6: pointer to original bcd value +# (*) fp0: mantissa accumulator +# ( ) FP_SCR1: working copy of original bcd value +# ( ) L_SCR1: copy of original exponent word +# +calc_m: + mov.l &1,%d1 # word counter, init to 1 + fmov.s &0x00000000,%fp0 # accumulator +# +# +# Since the packed number has a long word between the first & second parts, +# get the integer digit then skip down & get the rest of the +# mantissa. We will unroll the loop once. +# + bfextu (%a0){&28:&4},%d0 # integer part is ls digit in long word + fadd.b %d0,%fp0 # add digit to sum in fp0 +# +# +# Get the rest of the mantissa. +# +loadlw: + mov.l (%a0,%d1.L*4),%d4 # load mantissa lonqword into d4 + mov.l &FSTRT,%d3 # counter to pick up digits + mov.l &FNIBS,%d2 # reset number of digits per a0 ptr +md2b: + fmul.s &0x41200000,%fp0 # fp0 = fp0 * 10 + bfextu %d4{%d3:&4},%d0 # get the digit and zero extend + fadd.b %d0,%fp0 # fp0 = fp0 + digit +# +# +# If all the digits (8) in that long word have been converted (d2=0), +# then inc d1 (=2) to point to the next long word and reset d3 to 0 +# to initialize the digit offset, and set d2 to 7 for the digit count; +# else continue with this long word. +# + addq.b &4,%d3 # advance d3 to the next digit + dbf.w %d2,md2b # check for last digit in this lw +nextlw: + addq.l &1,%d1 # inc lw pointer in mantissa + cmp.l %d1,&2 # test for last lw + ble.b loadlw # if not, get last one +# +# Check the sign of the mant and make the value in fp0 the same sign. +# +m_sign: + btst &31,(%a0) # test sign of the mantissa + beq.b ap_st_z # if clear, go to append/strip zeros + fneg.x %fp0 # if set, negate fp0 +# +# Append/strip zeros: +# +# For adjusted exponents which have an absolute value greater than 27*, +# this routine calculates the amount needed to normalize the mantissa +# for the adjusted exponent. That number is subtracted from the exp +# if the exp was positive, and added if it was negative. The purpose +# of this is to reduce the value of the exponent and the possibility +# of error in calculation of pwrten. +# +# 1. Branch on the sign of the adjusted exponent. +# 2p.(positive exp) +# 2. Check M16 and the digits in lwords 2 and 3 in descending order. +# 3. Add one for each zero encountered until a non-zero digit. +# 4. Subtract the count from the exp. +# 5. Check if the exp has crossed zero in #3 above; make the exp abs +# and set SE. +# 6. Multiply the mantissa by 10**count. +# 2n.(negative exp) +# 2. Check the digits in lwords 3 and 2 in descending order. +# 3. Add one for each zero encountered until a non-zero digit. +# 4. Add the count to the exp. +# 5. Check if the exp has crossed zero in #3 above; clear SE. +# 6. Divide the mantissa by 10**count. +# +# *Why 27? If the adjusted exponent is within -28 < expA < 28, than +# any adjustment due to append/strip zeros will drive the resultane +# exponent towards zero. Since all pwrten constants with a power +# of 27 or less are exact, there is no need to use this routine to +# attempt to lessen the resultant exponent. +# +# Register usage: +# +# ap_st_z: +# (*) d0: temp digit storage +# (*) d1: zero count +# (*) d2: digit count +# (*) d3: offset pointer +# ( ) d4: first word of bcd +# (*) d5: lword counter +# ( ) a0: pointer to working bcd value +# ( ) FP_SCR1: working copy of original bcd value +# ( ) L_SCR1: copy of original exponent word +# +# +# First check the absolute value of the exponent to see if this +# routine is necessary. If so, then check the sign of the exponent +# and do append (+) or strip (-) zeros accordingly. +# This section handles a positive adjusted exponent. +# +ap_st_z: + mov.l (%sp),%d1 # load expA for range test + cmp.l %d1,&27 # test is with 27 + ble.w pwrten # if abs(expA) <28, skip ap/st zeros + btst &30,(%a0) # check sign of exp + bne.b ap_st_n # if neg, go to neg side + clr.l %d1 # zero count reg + mov.l (%a0),%d4 # load lword 1 to d4 + bfextu %d4{&28:&4},%d0 # get M16 in d0 + bne.b ap_p_fx # if M16 is non-zero, go fix exp + addq.l &1,%d1 # inc zero count + mov.l &1,%d5 # init lword counter + mov.l (%a0,%d5.L*4),%d4 # get lword 2 to d4 + bne.b ap_p_cl # if lw 2 is zero, skip it + addq.l &8,%d1 # and inc count by 8 + addq.l &1,%d5 # inc lword counter + mov.l (%a0,%d5.L*4),%d4 # get lword 3 to d4 +ap_p_cl: + clr.l %d3 # init offset reg + mov.l &7,%d2 # init digit counter +ap_p_gd: + bfextu %d4{%d3:&4},%d0 # get digit + bne.b ap_p_fx # if non-zero, go to fix exp + addq.l &4,%d3 # point to next digit + addq.l &1,%d1 # inc digit counter + dbf.w %d2,ap_p_gd # get next digit +ap_p_fx: + mov.l %d1,%d0 # copy counter to d2 + mov.l (%sp),%d1 # get adjusted exp from memory + sub.l %d0,%d1 # subtract count from exp + bge.b ap_p_fm # if still pos, go to pwrten + neg.l %d1 # now its neg; get abs + mov.l (%a0),%d4 # load lword 1 to d4 + or.l &0x40000000,%d4 # and set SE in d4 + or.l &0x40000000,(%a0) # and in memory +# +# Calculate the mantissa multiplier to compensate for the striping of +# zeros from the mantissa. +# +ap_p_fm: + lea.l PTENRN(%pc),%a1 # get address of power-of-ten table + clr.l %d3 # init table index + fmov.s &0x3f800000,%fp1 # init fp1 to 1 + mov.l &3,%d2 # init d2 to count bits in counter +ap_p_el: + asr.l &1,%d0 # shift lsb into carry + bcc.b ap_p_en # if 1, mul fp1 by pwrten factor + fmul.x (%a1,%d3),%fp1 # mul by 10**(d3_bit_no) +ap_p_en: + add.l &12,%d3 # inc d3 to next rtable entry + tst.l %d0 # check if d0 is zero + bne.b ap_p_el # if not, get next bit + fmul.x %fp1,%fp0 # mul mantissa by 10**(no_bits_shifted) + bra.b pwrten # go calc pwrten +# +# This section handles a negative adjusted exponent. +# +ap_st_n: + clr.l %d1 # clr counter + mov.l &2,%d5 # set up d5 to point to lword 3 + mov.l (%a0,%d5.L*4),%d4 # get lword 3 + bne.b ap_n_cl # if not zero, check digits + sub.l &1,%d5 # dec d5 to point to lword 2 + addq.l &8,%d1 # inc counter by 8 + mov.l (%a0,%d5.L*4),%d4 # get lword 2 +ap_n_cl: + mov.l &28,%d3 # point to last digit + mov.l &7,%d2 # init digit counter +ap_n_gd: + bfextu %d4{%d3:&4},%d0 # get digit + bne.b ap_n_fx # if non-zero, go to exp fix + subq.l &4,%d3 # point to previous digit + addq.l &1,%d1 # inc digit counter + dbf.w %d2,ap_n_gd # get next digit +ap_n_fx: + mov.l %d1,%d0 # copy counter to d0 + mov.l (%sp),%d1 # get adjusted exp from memory + sub.l %d0,%d1 # subtract count from exp + bgt.b ap_n_fm # if still pos, go fix mantissa + neg.l %d1 # take abs of exp and clr SE + mov.l (%a0),%d4 # load lword 1 to d4 + and.l &0xbfffffff,%d4 # and clr SE in d4 + and.l &0xbfffffff,(%a0) # and in memory +# +# Calculate the mantissa multiplier to compensate for the appending of +# zeros to the mantissa. +# +ap_n_fm: + lea.l PTENRN(%pc),%a1 # get address of power-of-ten table + clr.l %d3 # init table index + fmov.s &0x3f800000,%fp1 # init fp1 to 1 + mov.l &3,%d2 # init d2 to count bits in counter +ap_n_el: + asr.l &1,%d0 # shift lsb into carry + bcc.b ap_n_en # if 1, mul fp1 by pwrten factor + fmul.x (%a1,%d3),%fp1 # mul by 10**(d3_bit_no) +ap_n_en: + add.l &12,%d3 # inc d3 to next rtable entry + tst.l %d0 # check if d0 is zero + bne.b ap_n_el # if not, get next bit + fdiv.x %fp1,%fp0 # div mantissa by 10**(no_bits_shifted) +# +# +# Calculate power-of-ten factor from adjusted and shifted exponent. +# +# Register usage: +# +# pwrten: +# (*) d0: temp +# ( ) d1: exponent +# (*) d2: {FPCR[6:5],SM,SE} as index in RTABLE; temp +# (*) d3: FPCR work copy +# ( ) d4: first word of bcd +# (*) a1: RTABLE pointer +# calc_p: +# (*) d0: temp +# ( ) d1: exponent +# (*) d3: PWRTxx table index +# ( ) a0: pointer to working copy of bcd +# (*) a1: PWRTxx pointer +# (*) fp1: power-of-ten accumulator +# +# Pwrten calculates the exponent factor in the selected rounding mode +# according to the following table: +# +# Sign of Mant Sign of Exp Rounding Mode PWRTEN Rounding Mode +# +# ANY ANY RN RN +# +# + + RP RP +# - + RP RM +# + - RP RM +# - - RP RP +# +# + + RM RM +# - + RM RP +# + - RM RP +# - - RM RM +# +# + + RZ RM +# - + RZ RM +# + - RZ RP +# - - RZ RP +# +# +pwrten: + mov.l USER_FPCR(%a6),%d3 # get user's FPCR + bfextu %d3{&26:&2},%d2 # isolate rounding mode bits + mov.l (%a0),%d4 # reload 1st bcd word to d4 + asl.l &2,%d2 # format d2 to be + bfextu %d4{&0:&2},%d0 # {FPCR[6],FPCR[5],SM,SE} + add.l %d0,%d2 # in d2 as index into RTABLE + lea.l RTABLE(%pc),%a1 # load rtable base + mov.b (%a1,%d2),%d0 # load new rounding bits from table + clr.l %d3 # clear d3 to force no exc and extended + bfins %d0,%d3{&26:&2} # stuff new rounding bits in FPCR + fmov.l %d3,%fpcr # write new FPCR + asr.l &1,%d0 # write correct PTENxx table + bcc.b not_rp # to a1 + lea.l PTENRP(%pc),%a1 # it is RP + bra.b calc_p # go to init section +not_rp: + asr.l &1,%d0 # keep checking + bcc.b not_rm + lea.l PTENRM(%pc),%a1 # it is RM + bra.b calc_p # go to init section +not_rm: + lea.l PTENRN(%pc),%a1 # it is RN +calc_p: + mov.l %d1,%d0 # copy exp to d0;use d0 + bpl.b no_neg # if exp is negative, + neg.l %d0 # invert it + or.l &0x40000000,(%a0) # and set SE bit +no_neg: + clr.l %d3 # table index + fmov.s &0x3f800000,%fp1 # init fp1 to 1 +e_loop: + asr.l &1,%d0 # shift next bit into carry + bcc.b e_next # if zero, skip the mul + fmul.x (%a1,%d3),%fp1 # mul by 10**(d3_bit_no) +e_next: + add.l &12,%d3 # inc d3 to next rtable entry + tst.l %d0 # check if d0 is zero + bne.b e_loop # not zero, continue shifting +# +# +# Check the sign of the adjusted exp and make the value in fp0 the +# same sign. If the exp was pos then multiply fp1*fp0; +# else divide fp0/fp1. +# +# Register Usage: +# norm: +# ( ) a0: pointer to working bcd value +# (*) fp0: mantissa accumulator +# ( ) fp1: scaling factor - 10**(abs(exp)) +# +pnorm: + btst &30,(%a0) # test the sign of the exponent + beq.b mul # if clear, go to multiply +div: + fdiv.x %fp1,%fp0 # exp is negative, so divide mant by exp + bra.b end_dec +mul: + fmul.x %fp1,%fp0 # exp is positive, so multiply by exp +# +# +# Clean up and return with result in fp0. +# +# If the final mul/div in decbin incurred an inex exception, +# it will be inex2, but will be reported as inex1 by get_op. +# +end_dec: + fmov.l %fpsr,%d0 # get status register + bclr &inex2_bit+8,%d0 # test for inex2 and clear it + beq.b no_exc # skip this if no exc + ori.w &inx1a_mask,2+USER_FPSR(%a6) # set INEX1/AINEX +no_exc: + add.l &0x4,%sp # clear 1 lw param + fmovm.x (%sp)+,&0x40 # restore fp1 + movm.l (%sp)+,&0x3c # restore d2-d5 + fmov.l &0x0,%fpcr + fmov.l &0x0,%fpsr + rts + +######################################################################### +# bindec(): Converts an input in extended precision format to bcd format# +# # +# INPUT *************************************************************** # +# a0 = pointer to the input extended precision value in memory. # +# the input may be either normalized, unnormalized, or # +# denormalized. # +# d0 = contains the k-factor sign-extended to 32-bits. # +# # +# OUTPUT ************************************************************** # +# FP_SCR0(a6) = bcd format result on the stack. # +# # +# ALGORITHM *********************************************************** # +# # +# A1. Set RM and size ext; Set SIGMA = sign of input. # +# The k-factor is saved for use in d7. Clear the # +# BINDEC_FLG for separating normalized/denormalized # +# input. If input is unnormalized or denormalized, # +# normalize it. # +# # +# A2. Set X = abs(input). # +# # +# A3. Compute ILOG. # +# ILOG is the log base 10 of the input value. It is # +# approximated by adding e + 0.f when the original # +# value is viewed as 2^^e * 1.f in extended precision. # +# This value is stored in d6. # +# # +# A4. Clr INEX bit. # +# The operation in A3 above may have set INEX2. # +# # +# A5. Set ICTR = 0; # +# ICTR is a flag used in A13. It must be set before the # +# loop entry A6. # +# # +# A6. Calculate LEN. # +# LEN is the number of digits to be displayed. The # +# k-factor can dictate either the total number of digits, # +# if it is a positive number, or the number of digits # +# after the decimal point which are to be included as # +# significant. See the 68882 manual for examples. # +# If LEN is computed to be greater than 17, set OPERR in # +# USER_FPSR. LEN is stored in d4. # +# # +# A7. Calculate SCALE. # +# SCALE is equal to 10^ISCALE, where ISCALE is the number # +# of decimal places needed to insure LEN integer digits # +# in the output before conversion to bcd. LAMBDA is the # +# sign of ISCALE, used in A9. Fp1 contains # +# 10^^(abs(ISCALE)) using a rounding mode which is a # +# function of the original rounding mode and the signs # +# of ISCALE and X. A table is given in the code. # +# # +# A8. Clr INEX; Force RZ. # +# The operation in A3 above may have set INEX2. # +# RZ mode is forced for the scaling operation to insure # +# only one rounding error. The grs bits are collected in # +# the INEX flag for use in A10. # +# # +# A9. Scale X -> Y. # +# The mantissa is scaled to the desired number of # +# significant digits. The excess digits are collected # +# in INEX2. # +# # +# A10. Or in INEX. # +# If INEX is set, round error occurred. This is # +# compensated for by 'or-ing' in the INEX2 flag to # +# the lsb of Y. # +# # +# A11. Restore original FPCR; set size ext. # +# Perform FINT operation in the user's rounding mode. # +# Keep the size to extended. # +# # +# A12. Calculate YINT = FINT(Y) according to user's rounding # +# mode. The FPSP routine sintd0 is used. The output # +# is in fp0. # +# # +# A13. Check for LEN digits. # +# If the int operation results in more than LEN digits, # +# or less than LEN -1 digits, adjust ILOG and repeat from # +# A6. This test occurs only on the first pass. If the # +# result is exactly 10^LEN, decrement ILOG and divide # +# the mantissa by 10. # +# # +# A14. Convert the mantissa to bcd. # +# The binstr routine is used to convert the LEN digit # +# mantissa to bcd in memory. The input to binstr is # +# to be a fraction; i.e. (mantissa)/10^LEN and adjusted # +# such that the decimal point is to the left of bit 63. # +# The bcd digits are stored in the correct position in # +# the final string area in memory. # +# # +# A15. Convert the exponent to bcd. # +# As in A14 above, the exp is converted to bcd and the # +# digits are stored in the final string. # +# Test the length of the final exponent string. If the # +# length is 4, set operr. # +# # +# A16. Write sign bits to final string. # +# # +######################################################################### + +set BINDEC_FLG, EXC_TEMP # DENORM flag + +# Constants in extended precision +PLOG2: + long 0x3FFD0000,0x9A209A84,0xFBCFF798,0x00000000 +PLOG2UP1: + long 0x3FFD0000,0x9A209A84,0xFBCFF799,0x00000000 + +# Constants in single precision +FONE: + long 0x3F800000,0x00000000,0x00000000,0x00000000 +FTWO: + long 0x40000000,0x00000000,0x00000000,0x00000000 +FTEN: + long 0x41200000,0x00000000,0x00000000,0x00000000 +F4933: + long 0x459A2800,0x00000000,0x00000000,0x00000000 + +RBDTBL: + byte 0,0,0,0 + byte 3,3,2,2 + byte 3,2,2,3 + byte 2,3,3,2 + +# Implementation Notes: +# +# The registers are used as follows: +# +# d0: scratch; LEN input to binstr +# d1: scratch +# d2: upper 32-bits of mantissa for binstr +# d3: scratch;lower 32-bits of mantissa for binstr +# d4: LEN +# d5: LAMBDA/ICTR +# d6: ILOG +# d7: k-factor +# a0: ptr for original operand/final result +# a1: scratch pointer +# a2: pointer to FP_X; abs(original value) in ext +# fp0: scratch +# fp1: scratch +# fp2: scratch +# F_SCR1: +# F_SCR2: +# L_SCR1: +# L_SCR2: + + global bindec +bindec: + movm.l &0x3f20,-(%sp) # {%d2-%d7/%a2} + fmovm.x &0x7,-(%sp) # {%fp0-%fp2} + +# A1. Set RM and size ext. Set SIGMA = sign input; +# The k-factor is saved for use in d7. Clear BINDEC_FLG for +# separating normalized/denormalized input. If the input +# is a denormalized number, set the BINDEC_FLG memory word +# to signal denorm. If the input is unnormalized, normalize +# the input and test for denormalized result. +# + fmov.l &rm_mode*0x10,%fpcr # set RM and ext + mov.l (%a0),L_SCR2(%a6) # save exponent for sign check + mov.l %d0,%d7 # move k-factor to d7 + + clr.b BINDEC_FLG(%a6) # clr norm/denorm flag + cmpi.b STAG(%a6),&DENORM # is input a DENORM? + bne.w A2_str # no; input is a NORM + +# +# Normalize the denorm +# +un_de_norm: + mov.w (%a0),%d0 + and.w &0x7fff,%d0 # strip sign of normalized exp + mov.l 4(%a0),%d1 + mov.l 8(%a0),%d2 +norm_loop: + sub.w &1,%d0 + lsl.l &1,%d2 + roxl.l &1,%d1 + tst.l %d1 + bge.b norm_loop +# +# Test if the normalized input is denormalized +# + tst.w %d0 + bgt.b pos_exp # if greater than zero, it is a norm + st BINDEC_FLG(%a6) # set flag for denorm +pos_exp: + and.w &0x7fff,%d0 # strip sign of normalized exp + mov.w %d0,(%a0) + mov.l %d1,4(%a0) + mov.l %d2,8(%a0) + +# A2. Set X = abs(input). +# +A2_str: + mov.l (%a0),FP_SCR1(%a6) # move input to work space + mov.l 4(%a0),FP_SCR1+4(%a6) # move input to work space + mov.l 8(%a0),FP_SCR1+8(%a6) # move input to work space + and.l &0x7fffffff,FP_SCR1(%a6) # create abs(X) + +# A3. Compute ILOG. +# ILOG is the log base 10 of the input value. It is approx- +# imated by adding e + 0.f when the original value is viewed +# as 2^^e * 1.f in extended precision. This value is stored +# in d6. +# +# Register usage: +# Input/Output +# d0: k-factor/exponent +# d2: x/x +# d3: x/x +# d4: x/x +# d5: x/x +# d6: x/ILOG +# d7: k-factor/Unchanged +# a0: ptr for original operand/final result +# a1: x/x +# a2: x/x +# fp0: x/float(ILOG) +# fp1: x/x +# fp2: x/x +# F_SCR1:x/x +# F_SCR2:Abs(X)/Abs(X) with $3fff exponent +# L_SCR1:x/x +# L_SCR2:first word of X packed/Unchanged + + tst.b BINDEC_FLG(%a6) # check for denorm + beq.b A3_cont # if clr, continue with norm + mov.l &-4933,%d6 # force ILOG = -4933 + bra.b A4_str +A3_cont: + mov.w FP_SCR1(%a6),%d0 # move exp to d0 + mov.w &0x3fff,FP_SCR1(%a6) # replace exponent with 0x3fff + fmov.x FP_SCR1(%a6),%fp0 # now fp0 has 1.f + sub.w &0x3fff,%d0 # strip off bias + fadd.w %d0,%fp0 # add in exp + fsub.s FONE(%pc),%fp0 # subtract off 1.0 + fbge.w pos_res # if pos, branch + fmul.x PLOG2UP1(%pc),%fp0 # if neg, mul by LOG2UP1 + fmov.l %fp0,%d6 # put ILOG in d6 as a lword + bra.b A4_str # go move out ILOG +pos_res: + fmul.x PLOG2(%pc),%fp0 # if pos, mul by LOG2 + fmov.l %fp0,%d6 # put ILOG in d6 as a lword + + +# A4. Clr INEX bit. +# The operation in A3 above may have set INEX2. + +A4_str: + fmov.l &0,%fpsr # zero all of fpsr - nothing needed + + +# A5. Set ICTR = 0; +# ICTR is a flag used in A13. It must be set before the +# loop entry A6. The lower word of d5 is used for ICTR. + + clr.w %d5 # clear ICTR + +# A6. Calculate LEN. +# LEN is the number of digits to be displayed. The k-factor +# can dictate either the total number of digits, if it is +# a positive number, or the number of digits after the +# original decimal point which are to be included as +# significant. See the 68882 manual for examples. +# If LEN is computed to be greater than 17, set OPERR in +# USER_FPSR. LEN is stored in d4. +# +# Register usage: +# Input/Output +# d0: exponent/Unchanged +# d2: x/x/scratch +# d3: x/x +# d4: exc picture/LEN +# d5: ICTR/Unchanged +# d6: ILOG/Unchanged +# d7: k-factor/Unchanged +# a0: ptr for original operand/final result +# a1: x/x +# a2: x/x +# fp0: float(ILOG)/Unchanged +# fp1: x/x +# fp2: x/x +# F_SCR1:x/x +# F_SCR2:Abs(X) with $3fff exponent/Unchanged +# L_SCR1:x/x +# L_SCR2:first word of X packed/Unchanged + +A6_str: + tst.l %d7 # branch on sign of k + ble.b k_neg # if k <= 0, LEN = ILOG + 1 - k + mov.l %d7,%d4 # if k > 0, LEN = k + bra.b len_ck # skip to LEN check +k_neg: + mov.l %d6,%d4 # first load ILOG to d4 + sub.l %d7,%d4 # subtract off k + addq.l &1,%d4 # add in the 1 +len_ck: + tst.l %d4 # LEN check: branch on sign of LEN + ble.b LEN_ng # if neg, set LEN = 1 + cmp.l %d4,&17 # test if LEN > 17 + ble.b A7_str # if not, forget it + mov.l &17,%d4 # set max LEN = 17 + tst.l %d7 # if negative, never set OPERR + ble.b A7_str # if positive, continue + or.l &opaop_mask,USER_FPSR(%a6) # set OPERR & AIOP in USER_FPSR + bra.b A7_str # finished here +LEN_ng: + mov.l &1,%d4 # min LEN is 1 + + +# A7. Calculate SCALE. +# SCALE is equal to 10^ISCALE, where ISCALE is the number +# of decimal places needed to insure LEN integer digits +# in the output before conversion to bcd. LAMBDA is the sign +# of ISCALE, used in A9. Fp1 contains 10^^(abs(ISCALE)) using +# the rounding mode as given in the following table (see +# Coonen, p. 7.23 as ref.; however, the SCALE variable is +# of opposite sign in bindec.sa from Coonen). +# +# Initial USE +# FPCR[6:5] LAMBDA SIGN(X) FPCR[6:5] +# ---------------------------------------------- +# RN 00 0 0 00/0 RN +# RN 00 0 1 00/0 RN +# RN 00 1 0 00/0 RN +# RN 00 1 1 00/0 RN +# RZ 01 0 0 11/3 RP +# RZ 01 0 1 11/3 RP +# RZ 01 1 0 10/2 RM +# RZ 01 1 1 10/2 RM +# RM 10 0 0 11/3 RP +# RM 10 0 1 10/2 RM +# RM 10 1 0 10/2 RM +# RM 10 1 1 11/3 RP +# RP 11 0 0 10/2 RM +# RP 11 0 1 11/3 RP +# RP 11 1 0 11/3 RP +# RP 11 1 1 10/2 RM +# +# Register usage: +# Input/Output +# d0: exponent/scratch - final is 0 +# d2: x/0 or 24 for A9 +# d3: x/scratch - offset ptr into PTENRM array +# d4: LEN/Unchanged +# d5: 0/ICTR:LAMBDA +# d6: ILOG/ILOG or k if ((k<=0)&(ILOG<k)) +# d7: k-factor/Unchanged +# a0: ptr for original operand/final result +# a1: x/ptr to PTENRM array +# a2: x/x +# fp0: float(ILOG)/Unchanged +# fp1: x/10^ISCALE +# fp2: x/x +# F_SCR1:x/x +# F_SCR2:Abs(X) with $3fff exponent/Unchanged +# L_SCR1:x/x +# L_SCR2:first word of X packed/Unchanged + +A7_str: + tst.l %d7 # test sign of k + bgt.b k_pos # if pos and > 0, skip this + cmp.l %d7,%d6 # test k - ILOG + blt.b k_pos # if ILOG >= k, skip this + mov.l %d7,%d6 # if ((k<0) & (ILOG < k)) ILOG = k +k_pos: + mov.l %d6,%d0 # calc ILOG + 1 - LEN in d0 + addq.l &1,%d0 # add the 1 + sub.l %d4,%d0 # sub off LEN + swap %d5 # use upper word of d5 for LAMBDA + clr.w %d5 # set it zero initially + clr.w %d2 # set up d2 for very small case + tst.l %d0 # test sign of ISCALE + bge.b iscale # if pos, skip next inst + addq.w &1,%d5 # if neg, set LAMBDA true + cmp.l %d0,&0xffffecd4 # test iscale <= -4908 + bgt.b no_inf # if false, skip rest + add.l &24,%d0 # add in 24 to iscale + mov.l &24,%d2 # put 24 in d2 for A9 +no_inf: + neg.l %d0 # and take abs of ISCALE +iscale: + fmov.s FONE(%pc),%fp1 # init fp1 to 1 + bfextu USER_FPCR(%a6){&26:&2},%d1 # get initial rmode bits + lsl.w &1,%d1 # put them in bits 2:1 + add.w %d5,%d1 # add in LAMBDA + lsl.w &1,%d1 # put them in bits 3:1 + tst.l L_SCR2(%a6) # test sign of original x + bge.b x_pos # if pos, don't set bit 0 + addq.l &1,%d1 # if neg, set bit 0 +x_pos: + lea.l RBDTBL(%pc),%a2 # load rbdtbl base + mov.b (%a2,%d1),%d3 # load d3 with new rmode + lsl.l &4,%d3 # put bits in proper position + fmov.l %d3,%fpcr # load bits into fpu + lsr.l &4,%d3 # put bits in proper position + tst.b %d3 # decode new rmode for pten table + bne.b not_rn # if zero, it is RN + lea.l PTENRN(%pc),%a1 # load a1 with RN table base + bra.b rmode # exit decode +not_rn: + lsr.b &1,%d3 # get lsb in carry + bcc.b not_rp2 # if carry clear, it is RM + lea.l PTENRP(%pc),%a1 # load a1 with RP table base + bra.b rmode # exit decode +not_rp2: + lea.l PTENRM(%pc),%a1 # load a1 with RM table base +rmode: + clr.l %d3 # clr table index +e_loop2: + lsr.l &1,%d0 # shift next bit into carry + bcc.b e_next2 # if zero, skip the mul + fmul.x (%a1,%d3),%fp1 # mul by 10**(d3_bit_no) +e_next2: + add.l &12,%d3 # inc d3 to next pwrten table entry + tst.l %d0 # test if ISCALE is zero + bne.b e_loop2 # if not, loop + +# A8. Clr INEX; Force RZ. +# The operation in A3 above may have set INEX2. +# RZ mode is forced for the scaling operation to insure +# only one rounding error. The grs bits are collected in +# the INEX flag for use in A10. +# +# Register usage: +# Input/Output + + fmov.l &0,%fpsr # clr INEX + fmov.l &rz_mode*0x10,%fpcr # set RZ rounding mode + +# A9. Scale X -> Y. +# The mantissa is scaled to the desired number of significant +# digits. The excess digits are collected in INEX2. If mul, +# Check d2 for excess 10 exponential value. If not zero, +# the iscale value would have caused the pwrten calculation +# to overflow. Only a negative iscale can cause this, so +# multiply by 10^(d2), which is now only allowed to be 24, +# with a multiply by 10^8 and 10^16, which is exact since +# 10^24 is exact. If the input was denormalized, we must +# create a busy stack frame with the mul command and the +# two operands, and allow the fpu to complete the multiply. +# +# Register usage: +# Input/Output +# d0: FPCR with RZ mode/Unchanged +# d2: 0 or 24/unchanged +# d3: x/x +# d4: LEN/Unchanged +# d5: ICTR:LAMBDA +# d6: ILOG/Unchanged +# d7: k-factor/Unchanged +# a0: ptr for original operand/final result +# a1: ptr to PTENRM array/Unchanged +# a2: x/x +# fp0: float(ILOG)/X adjusted for SCALE (Y) +# fp1: 10^ISCALE/Unchanged +# fp2: x/x +# F_SCR1:x/x +# F_SCR2:Abs(X) with $3fff exponent/Unchanged +# L_SCR1:x/x +# L_SCR2:first word of X packed/Unchanged + +A9_str: + fmov.x (%a0),%fp0 # load X from memory + fabs.x %fp0 # use abs(X) + tst.w %d5 # LAMBDA is in lower word of d5 + bne.b sc_mul # if neg (LAMBDA = 1), scale by mul + fdiv.x %fp1,%fp0 # calculate X / SCALE -> Y to fp0 + bra.w A10_st # branch to A10 + +sc_mul: + tst.b BINDEC_FLG(%a6) # check for denorm + beq.w A9_norm # if norm, continue with mul + +# for DENORM, we must calculate: +# fp0 = input_op * 10^ISCALE * 10^24 +# since the input operand is a DENORM, we can't multiply it directly. +# so, we do the multiplication of the exponents and mantissas separately. +# in this way, we avoid underflow on intermediate stages of the +# multiplication and guarantee a result without exception. + fmovm.x &0x2,-(%sp) # save 10^ISCALE to stack + + mov.w (%sp),%d3 # grab exponent + andi.w &0x7fff,%d3 # clear sign + ori.w &0x8000,(%a0) # make DENORM exp negative + add.w (%a0),%d3 # add DENORM exp to 10^ISCALE exp + subi.w &0x3fff,%d3 # subtract BIAS + add.w 36(%a1),%d3 + subi.w &0x3fff,%d3 # subtract BIAS + add.w 48(%a1),%d3 + subi.w &0x3fff,%d3 # subtract BIAS + + bmi.w sc_mul_err # is result is DENORM, punt!!! + + andi.w &0x8000,(%sp) # keep sign + or.w %d3,(%sp) # insert new exponent + andi.w &0x7fff,(%a0) # clear sign bit on DENORM again + mov.l 0x8(%a0),-(%sp) # put input op mantissa on stk + mov.l 0x4(%a0),-(%sp) + mov.l &0x3fff0000,-(%sp) # force exp to zero + fmovm.x (%sp)+,&0x80 # load normalized DENORM into fp0 + fmul.x (%sp)+,%fp0 + +# fmul.x 36(%a1),%fp0 # multiply fp0 by 10^8 +# fmul.x 48(%a1),%fp0 # multiply fp0 by 10^16 + mov.l 36+8(%a1),-(%sp) # get 10^8 mantissa + mov.l 36+4(%a1),-(%sp) + mov.l &0x3fff0000,-(%sp) # force exp to zero + mov.l 48+8(%a1),-(%sp) # get 10^16 mantissa + mov.l 48+4(%a1),-(%sp) + mov.l &0x3fff0000,-(%sp)# force exp to zero + fmul.x (%sp)+,%fp0 # multiply fp0 by 10^8 + fmul.x (%sp)+,%fp0 # multiply fp0 by 10^16 + bra.b A10_st + +sc_mul_err: + bra.b sc_mul_err + +A9_norm: + tst.w %d2 # test for small exp case + beq.b A9_con # if zero, continue as normal + fmul.x 36(%a1),%fp0 # multiply fp0 by 10^8 + fmul.x 48(%a1),%fp0 # multiply fp0 by 10^16 +A9_con: + fmul.x %fp1,%fp0 # calculate X * SCALE -> Y to fp0 + +# A10. Or in INEX. +# If INEX is set, round error occurred. This is compensated +# for by 'or-ing' in the INEX2 flag to the lsb of Y. +# +# Register usage: +# Input/Output +# d0: FPCR with RZ mode/FPSR with INEX2 isolated +# d2: x/x +# d3: x/x +# d4: LEN/Unchanged +# d5: ICTR:LAMBDA +# d6: ILOG/Unchanged +# d7: k-factor/Unchanged +# a0: ptr for original operand/final result +# a1: ptr to PTENxx array/Unchanged +# a2: x/ptr to FP_SCR1(a6) +# fp0: Y/Y with lsb adjusted +# fp1: 10^ISCALE/Unchanged +# fp2: x/x + +A10_st: + fmov.l %fpsr,%d0 # get FPSR + fmov.x %fp0,FP_SCR1(%a6) # move Y to memory + lea.l FP_SCR1(%a6),%a2 # load a2 with ptr to FP_SCR1 + btst &9,%d0 # check if INEX2 set + beq.b A11_st # if clear, skip rest + or.l &1,8(%a2) # or in 1 to lsb of mantissa + fmov.x FP_SCR1(%a6),%fp0 # write adjusted Y back to fpu + + +# A11. Restore original FPCR; set size ext. +# Perform FINT operation in the user's rounding mode. Keep +# the size to extended. The sintdo entry point in the sint +# routine expects the FPCR value to be in USER_FPCR for +# mode and precision. The original FPCR is saved in L_SCR1. + +A11_st: + mov.l USER_FPCR(%a6),L_SCR1(%a6) # save it for later + and.l &0x00000030,USER_FPCR(%a6) # set size to ext, +# ;block exceptions + + +# A12. Calculate YINT = FINT(Y) according to user's rounding mode. +# The FPSP routine sintd0 is used. The output is in fp0. +# +# Register usage: +# Input/Output +# d0: FPSR with AINEX cleared/FPCR with size set to ext +# d2: x/x/scratch +# d3: x/x +# d4: LEN/Unchanged +# d5: ICTR:LAMBDA/Unchanged +# d6: ILOG/Unchanged +# d7: k-factor/Unchanged +# a0: ptr for original operand/src ptr for sintdo +# a1: ptr to PTENxx array/Unchanged +# a2: ptr to FP_SCR1(a6)/Unchanged +# a6: temp pointer to FP_SCR1(a6) - orig value saved and restored +# fp0: Y/YINT +# fp1: 10^ISCALE/Unchanged +# fp2: x/x +# F_SCR1:x/x +# F_SCR2:Y adjusted for inex/Y with original exponent +# L_SCR1:x/original USER_FPCR +# L_SCR2:first word of X packed/Unchanged + +A12_st: + movm.l &0xc0c0,-(%sp) # save regs used by sintd0 {%d0-%d1/%a0-%a1} + mov.l L_SCR1(%a6),-(%sp) + mov.l L_SCR2(%a6),-(%sp) + + lea.l FP_SCR1(%a6),%a0 # a0 is ptr to FP_SCR1(a6) + fmov.x %fp0,(%a0) # move Y to memory at FP_SCR1(a6) + tst.l L_SCR2(%a6) # test sign of original operand + bge.b do_fint12 # if pos, use Y + or.l &0x80000000,(%a0) # if neg, use -Y +do_fint12: + mov.l USER_FPSR(%a6),-(%sp) +# bsr sintdo # sint routine returns int in fp0 + + fmov.l USER_FPCR(%a6),%fpcr + fmov.l &0x0,%fpsr # clear the AEXC bits!!! +## mov.l USER_FPCR(%a6),%d0 # ext prec/keep rnd mode +## andi.l &0x00000030,%d0 +## fmov.l %d0,%fpcr + fint.x FP_SCR1(%a6),%fp0 # do fint() + fmov.l %fpsr,%d0 + or.w %d0,FPSR_EXCEPT(%a6) +## fmov.l &0x0,%fpcr +## fmov.l %fpsr,%d0 # don't keep ccodes +## or.w %d0,FPSR_EXCEPT(%a6) + + mov.b (%sp),USER_FPSR(%a6) + add.l &4,%sp + + mov.l (%sp)+,L_SCR2(%a6) + mov.l (%sp)+,L_SCR1(%a6) + movm.l (%sp)+,&0x303 # restore regs used by sint {%d0-%d1/%a0-%a1} + + mov.l L_SCR2(%a6),FP_SCR1(%a6) # restore original exponent + mov.l L_SCR1(%a6),USER_FPCR(%a6) # restore user's FPCR + +# A13. Check for LEN digits. +# If the int operation results in more than LEN digits, +# or less than LEN -1 digits, adjust ILOG and repeat from +# A6. This test occurs only on the first pass. If the +# result is exactly 10^LEN, decrement ILOG and divide +# the mantissa by 10. The calculation of 10^LEN cannot +# be inexact, since all powers of ten up to 10^27 are exact +# in extended precision, so the use of a previous power-of-ten +# table will introduce no error. +# +# +# Register usage: +# Input/Output +# d0: FPCR with size set to ext/scratch final = 0 +# d2: x/x +# d3: x/scratch final = x +# d4: LEN/LEN adjusted +# d5: ICTR:LAMBDA/LAMBDA:ICTR +# d6: ILOG/ILOG adjusted +# d7: k-factor/Unchanged +# a0: pointer into memory for packed bcd string formation +# a1: ptr to PTENxx array/Unchanged +# a2: ptr to FP_SCR1(a6)/Unchanged +# fp0: int portion of Y/abs(YINT) adjusted +# fp1: 10^ISCALE/Unchanged +# fp2: x/10^LEN +# F_SCR1:x/x +# F_SCR2:Y with original exponent/Unchanged +# L_SCR1:original USER_FPCR/Unchanged +# L_SCR2:first word of X packed/Unchanged + +A13_st: + swap %d5 # put ICTR in lower word of d5 + tst.w %d5 # check if ICTR = 0 + bne not_zr # if non-zero, go to second test +# +# Compute 10^(LEN-1) +# + fmov.s FONE(%pc),%fp2 # init fp2 to 1.0 + mov.l %d4,%d0 # put LEN in d0 + subq.l &1,%d0 # d0 = LEN -1 + clr.l %d3 # clr table index +l_loop: + lsr.l &1,%d0 # shift next bit into carry + bcc.b l_next # if zero, skip the mul + fmul.x (%a1,%d3),%fp2 # mul by 10**(d3_bit_no) +l_next: + add.l &12,%d3 # inc d3 to next pwrten table entry + tst.l %d0 # test if LEN is zero + bne.b l_loop # if not, loop +# +# 10^LEN-1 is computed for this test and A14. If the input was +# denormalized, check only the case in which YINT > 10^LEN. +# + tst.b BINDEC_FLG(%a6) # check if input was norm + beq.b A13_con # if norm, continue with checking + fabs.x %fp0 # take abs of YINT + bra test_2 +# +# Compare abs(YINT) to 10^(LEN-1) and 10^LEN +# +A13_con: + fabs.x %fp0 # take abs of YINT + fcmp.x %fp0,%fp2 # compare abs(YINT) with 10^(LEN-1) + fbge.w test_2 # if greater, do next test + subq.l &1,%d6 # subtract 1 from ILOG + mov.w &1,%d5 # set ICTR + fmov.l &rm_mode*0x10,%fpcr # set rmode to RM + fmul.s FTEN(%pc),%fp2 # compute 10^LEN + bra.w A6_str # return to A6 and recompute YINT +test_2: + fmul.s FTEN(%pc),%fp2 # compute 10^LEN + fcmp.x %fp0,%fp2 # compare abs(YINT) with 10^LEN + fblt.w A14_st # if less, all is ok, go to A14 + fbgt.w fix_ex # if greater, fix and redo + fdiv.s FTEN(%pc),%fp0 # if equal, divide by 10 + addq.l &1,%d6 # and inc ILOG + bra.b A14_st # and continue elsewhere +fix_ex: + addq.l &1,%d6 # increment ILOG by 1 + mov.w &1,%d5 # set ICTR + fmov.l &rm_mode*0x10,%fpcr # set rmode to RM + bra.w A6_str # return to A6 and recompute YINT +# +# Since ICTR <> 0, we have already been through one adjustment, +# and shouldn't have another; this is to check if abs(YINT) = 10^LEN +# 10^LEN is again computed using whatever table is in a1 since the +# value calculated cannot be inexact. +# +not_zr: + fmov.s FONE(%pc),%fp2 # init fp2 to 1.0 + mov.l %d4,%d0 # put LEN in d0 + clr.l %d3 # clr table index +z_loop: + lsr.l &1,%d0 # shift next bit into carry + bcc.b z_next # if zero, skip the mul + fmul.x (%a1,%d3),%fp2 # mul by 10**(d3_bit_no) +z_next: + add.l &12,%d3 # inc d3 to next pwrten table entry + tst.l %d0 # test if LEN is zero + bne.b z_loop # if not, loop + fabs.x %fp0 # get abs(YINT) + fcmp.x %fp0,%fp2 # check if abs(YINT) = 10^LEN + fbneq.w A14_st # if not, skip this + fdiv.s FTEN(%pc),%fp0 # divide abs(YINT) by 10 + addq.l &1,%d6 # and inc ILOG by 1 + addq.l &1,%d4 # and inc LEN + fmul.s FTEN(%pc),%fp2 # if LEN++, the get 10^^LEN + +# A14. Convert the mantissa to bcd. +# The binstr routine is used to convert the LEN digit +# mantissa to bcd in memory. The input to binstr is +# to be a fraction; i.e. (mantissa)/10^LEN and adjusted +# such that the decimal point is to the left of bit 63. +# The bcd digits are stored in the correct position in +# the final string area in memory. +# +# +# Register usage: +# Input/Output +# d0: x/LEN call to binstr - final is 0 +# d1: x/0 +# d2: x/ms 32-bits of mant of abs(YINT) +# d3: x/ls 32-bits of mant of abs(YINT) +# d4: LEN/Unchanged +# d5: ICTR:LAMBDA/LAMBDA:ICTR +# d6: ILOG +# d7: k-factor/Unchanged +# a0: pointer into memory for packed bcd string formation +# /ptr to first mantissa byte in result string +# a1: ptr to PTENxx array/Unchanged +# a2: ptr to FP_SCR1(a6)/Unchanged +# fp0: int portion of Y/abs(YINT) adjusted +# fp1: 10^ISCALE/Unchanged +# fp2: 10^LEN/Unchanged +# F_SCR1:x/Work area for final result +# F_SCR2:Y with original exponent/Unchanged +# L_SCR1:original USER_FPCR/Unchanged +# L_SCR2:first word of X packed/Unchanged + +A14_st: + fmov.l &rz_mode*0x10,%fpcr # force rz for conversion + fdiv.x %fp2,%fp0 # divide abs(YINT) by 10^LEN + lea.l FP_SCR0(%a6),%a0 + fmov.x %fp0,(%a0) # move abs(YINT)/10^LEN to memory + mov.l 4(%a0),%d2 # move 2nd word of FP_RES to d2 + mov.l 8(%a0),%d3 # move 3rd word of FP_RES to d3 + clr.l 4(%a0) # zero word 2 of FP_RES + clr.l 8(%a0) # zero word 3 of FP_RES + mov.l (%a0),%d0 # move exponent to d0 + swap %d0 # put exponent in lower word + beq.b no_sft # if zero, don't shift + sub.l &0x3ffd,%d0 # sub bias less 2 to make fract + tst.l %d0 # check if > 1 + bgt.b no_sft # if so, don't shift + neg.l %d0 # make exp positive +m_loop: + lsr.l &1,%d2 # shift d2:d3 right, add 0s + roxr.l &1,%d3 # the number of places + dbf.w %d0,m_loop # given in d0 +no_sft: + tst.l %d2 # check for mantissa of zero + bne.b no_zr # if not, go on + tst.l %d3 # continue zero check + beq.b zer_m # if zero, go directly to binstr +no_zr: + clr.l %d1 # put zero in d1 for addx + add.l &0x00000080,%d3 # inc at bit 7 + addx.l %d1,%d2 # continue inc + and.l &0xffffff80,%d3 # strip off lsb not used by 882 +zer_m: + mov.l %d4,%d0 # put LEN in d0 for binstr call + addq.l &3,%a0 # a0 points to M16 byte in result + bsr binstr # call binstr to convert mant + + +# A15. Convert the exponent to bcd. +# As in A14 above, the exp is converted to bcd and the +# digits are stored in the final string. +# +# Digits are stored in L_SCR1(a6) on return from BINDEC as: +# +# 32 16 15 0 +# ----------------------------------------- +# | 0 | e3 | e2 | e1 | e4 | X | X | X | +# ----------------------------------------- +# +# And are moved into their proper places in FP_SCR0. If digit e4 +# is non-zero, OPERR is signaled. In all cases, all 4 digits are +# written as specified in the 881/882 manual for packed decimal. +# +# Register usage: +# Input/Output +# d0: x/LEN call to binstr - final is 0 +# d1: x/scratch (0);shift count for final exponent packing +# d2: x/ms 32-bits of exp fraction/scratch +# d3: x/ls 32-bits of exp fraction +# d4: LEN/Unchanged +# d5: ICTR:LAMBDA/LAMBDA:ICTR +# d6: ILOG +# d7: k-factor/Unchanged +# a0: ptr to result string/ptr to L_SCR1(a6) +# a1: ptr to PTENxx array/Unchanged +# a2: ptr to FP_SCR1(a6)/Unchanged +# fp0: abs(YINT) adjusted/float(ILOG) +# fp1: 10^ISCALE/Unchanged +# fp2: 10^LEN/Unchanged +# F_SCR1:Work area for final result/BCD result +# F_SCR2:Y with original exponent/ILOG/10^4 +# L_SCR1:original USER_FPCR/Exponent digits on return from binstr +# L_SCR2:first word of X packed/Unchanged + +A15_st: + tst.b BINDEC_FLG(%a6) # check for denorm + beq.b not_denorm + ftest.x %fp0 # test for zero + fbeq.w den_zero # if zero, use k-factor or 4933 + fmov.l %d6,%fp0 # float ILOG + fabs.x %fp0 # get abs of ILOG + bra.b convrt +den_zero: + tst.l %d7 # check sign of the k-factor + blt.b use_ilog # if negative, use ILOG + fmov.s F4933(%pc),%fp0 # force exponent to 4933 + bra.b convrt # do it +use_ilog: + fmov.l %d6,%fp0 # float ILOG + fabs.x %fp0 # get abs of ILOG + bra.b convrt +not_denorm: + ftest.x %fp0 # test for zero + fbneq.w not_zero # if zero, force exponent + fmov.s FONE(%pc),%fp0 # force exponent to 1 + bra.b convrt # do it +not_zero: + fmov.l %d6,%fp0 # float ILOG + fabs.x %fp0 # get abs of ILOG +convrt: + fdiv.x 24(%a1),%fp0 # compute ILOG/10^4 + fmov.x %fp0,FP_SCR1(%a6) # store fp0 in memory + mov.l 4(%a2),%d2 # move word 2 to d2 + mov.l 8(%a2),%d3 # move word 3 to d3 + mov.w (%a2),%d0 # move exp to d0 + beq.b x_loop_fin # if zero, skip the shift + sub.w &0x3ffd,%d0 # subtract off bias + neg.w %d0 # make exp positive +x_loop: + lsr.l &1,%d2 # shift d2:d3 right + roxr.l &1,%d3 # the number of places + dbf.w %d0,x_loop # given in d0 +x_loop_fin: + clr.l %d1 # put zero in d1 for addx + add.l &0x00000080,%d3 # inc at bit 6 + addx.l %d1,%d2 # continue inc + and.l &0xffffff80,%d3 # strip off lsb not used by 882 + mov.l &4,%d0 # put 4 in d0 for binstr call + lea.l L_SCR1(%a6),%a0 # a0 is ptr to L_SCR1 for exp digits + bsr binstr # call binstr to convert exp + mov.l L_SCR1(%a6),%d0 # load L_SCR1 lword to d0 + mov.l &12,%d1 # use d1 for shift count + lsr.l %d1,%d0 # shift d0 right by 12 + bfins %d0,FP_SCR0(%a6){&4:&12} # put e3:e2:e1 in FP_SCR0 + lsr.l %d1,%d0 # shift d0 right by 12 + bfins %d0,FP_SCR0(%a6){&16:&4} # put e4 in FP_SCR0 + tst.b %d0 # check if e4 is zero + beq.b A16_st # if zero, skip rest + or.l &opaop_mask,USER_FPSR(%a6) # set OPERR & AIOP in USER_FPSR + + +# A16. Write sign bits to final string. +# Sigma is bit 31 of initial value; RHO is bit 31 of d6 (ILOG). +# +# Register usage: +# Input/Output +# d0: x/scratch - final is x +# d2: x/x +# d3: x/x +# d4: LEN/Unchanged +# d5: ICTR:LAMBDA/LAMBDA:ICTR +# d6: ILOG/ILOG adjusted +# d7: k-factor/Unchanged +# a0: ptr to L_SCR1(a6)/Unchanged +# a1: ptr to PTENxx array/Unchanged +# a2: ptr to FP_SCR1(a6)/Unchanged +# fp0: float(ILOG)/Unchanged +# fp1: 10^ISCALE/Unchanged +# fp2: 10^LEN/Unchanged +# F_SCR1:BCD result with correct signs +# F_SCR2:ILOG/10^4 +# L_SCR1:Exponent digits on return from binstr +# L_SCR2:first word of X packed/Unchanged + +A16_st: + clr.l %d0 # clr d0 for collection of signs + and.b &0x0f,FP_SCR0(%a6) # clear first nibble of FP_SCR0 + tst.l L_SCR2(%a6) # check sign of original mantissa + bge.b mant_p # if pos, don't set SM + mov.l &2,%d0 # move 2 in to d0 for SM +mant_p: + tst.l %d6 # check sign of ILOG + bge.b wr_sgn # if pos, don't set SE + addq.l &1,%d0 # set bit 0 in d0 for SE +wr_sgn: + bfins %d0,FP_SCR0(%a6){&0:&2} # insert SM and SE into FP_SCR0 + +# Clean up and restore all registers used. + + fmov.l &0,%fpsr # clear possible inex2/ainex bits + fmovm.x (%sp)+,&0xe0 # {%fp0-%fp2} + movm.l (%sp)+,&0x4fc # {%d2-%d7/%a2} + rts + + global PTENRN +PTENRN: + long 0x40020000,0xA0000000,0x00000000 # 10 ^ 1 + long 0x40050000,0xC8000000,0x00000000 # 10 ^ 2 + long 0x400C0000,0x9C400000,0x00000000 # 10 ^ 4 + long 0x40190000,0xBEBC2000,0x00000000 # 10 ^ 8 + long 0x40340000,0x8E1BC9BF,0x04000000 # 10 ^ 16 + long 0x40690000,0x9DC5ADA8,0x2B70B59E # 10 ^ 32 + long 0x40D30000,0xC2781F49,0xFFCFA6D5 # 10 ^ 64 + long 0x41A80000,0x93BA47C9,0x80E98CE0 # 10 ^ 128 + long 0x43510000,0xAA7EEBFB,0x9DF9DE8E # 10 ^ 256 + long 0x46A30000,0xE319A0AE,0xA60E91C7 # 10 ^ 512 + long 0x4D480000,0xC9767586,0x81750C17 # 10 ^ 1024 + long 0x5A920000,0x9E8B3B5D,0xC53D5DE5 # 10 ^ 2048 + long 0x75250000,0xC4605202,0x8A20979B # 10 ^ 4096 + + global PTENRP +PTENRP: + long 0x40020000,0xA0000000,0x00000000 # 10 ^ 1 + long 0x40050000,0xC8000000,0x00000000 # 10 ^ 2 + long 0x400C0000,0x9C400000,0x00000000 # 10 ^ 4 + long 0x40190000,0xBEBC2000,0x00000000 # 10 ^ 8 + long 0x40340000,0x8E1BC9BF,0x04000000 # 10 ^ 16 + long 0x40690000,0x9DC5ADA8,0x2B70B59E # 10 ^ 32 + long 0x40D30000,0xC2781F49,0xFFCFA6D6 # 10 ^ 64 + long 0x41A80000,0x93BA47C9,0x80E98CE0 # 10 ^ 128 + long 0x43510000,0xAA7EEBFB,0x9DF9DE8E # 10 ^ 256 + long 0x46A30000,0xE319A0AE,0xA60E91C7 # 10 ^ 512 + long 0x4D480000,0xC9767586,0x81750C18 # 10 ^ 1024 + long 0x5A920000,0x9E8B3B5D,0xC53D5DE5 # 10 ^ 2048 + long 0x75250000,0xC4605202,0x8A20979B # 10 ^ 4096 + + global PTENRM +PTENRM: + long 0x40020000,0xA0000000,0x00000000 # 10 ^ 1 + long 0x40050000,0xC8000000,0x00000000 # 10 ^ 2 + long 0x400C0000,0x9C400000,0x00000000 # 10 ^ 4 + long 0x40190000,0xBEBC2000,0x00000000 # 10 ^ 8 + long 0x40340000,0x8E1BC9BF,0x04000000 # 10 ^ 16 + long 0x40690000,0x9DC5ADA8,0x2B70B59D # 10 ^ 32 + long 0x40D30000,0xC2781F49,0xFFCFA6D5 # 10 ^ 64 + long 0x41A80000,0x93BA47C9,0x80E98CDF # 10 ^ 128 + long 0x43510000,0xAA7EEBFB,0x9DF9DE8D # 10 ^ 256 + long 0x46A30000,0xE319A0AE,0xA60E91C6 # 10 ^ 512 + long 0x4D480000,0xC9767586,0x81750C17 # 10 ^ 1024 + long 0x5A920000,0x9E8B3B5D,0xC53D5DE4 # 10 ^ 2048 + long 0x75250000,0xC4605202,0x8A20979A # 10 ^ 4096 + +######################################################################### +# binstr(): Converts a 64-bit binary integer to bcd. # +# # +# INPUT *************************************************************** # +# d2:d3 = 64-bit binary integer # +# d0 = desired length (LEN) # +# a0 = pointer to start in memory for bcd characters # +# (This pointer must point to byte 4 of the first # +# lword of the packed decimal memory string.) # +# # +# OUTPUT ************************************************************** # +# a0 = pointer to LEN bcd digits representing the 64-bit integer. # +# # +# ALGORITHM *********************************************************** # +# The 64-bit binary is assumed to have a decimal point before # +# bit 63. The fraction is multiplied by 10 using a mul by 2 # +# shift and a mul by 8 shift. The bits shifted out of the # +# msb form a decimal digit. This process is iterated until # +# LEN digits are formed. # +# # +# A1. Init d7 to 1. D7 is the byte digit counter, and if 1, the # +# digit formed will be assumed the least significant. This is # +# to force the first byte formed to have a 0 in the upper 4 bits. # +# # +# A2. Beginning of the loop: # +# Copy the fraction in d2:d3 to d4:d5. # +# # +# A3. Multiply the fraction in d2:d3 by 8 using bit-field # +# extracts and shifts. The three msbs from d2 will go into d1. # +# # +# A4. Multiply the fraction in d4:d5 by 2 using shifts. The msb # +# will be collected by the carry. # +# # +# A5. Add using the carry the 64-bit quantities in d2:d3 and d4:d5 # +# into d2:d3. D1 will contain the bcd digit formed. # +# # +# A6. Test d7. If zero, the digit formed is the ms digit. If non- # +# zero, it is the ls digit. Put the digit in its place in the # +# upper word of d0. If it is the ls digit, write the word # +# from d0 to memory. # +# # +# A7. Decrement d6 (LEN counter) and repeat the loop until zero. # +# # +######################################################################### + +# Implementation Notes: +# +# The registers are used as follows: +# +# d0: LEN counter +# d1: temp used to form the digit +# d2: upper 32-bits of fraction for mul by 8 +# d3: lower 32-bits of fraction for mul by 8 +# d4: upper 32-bits of fraction for mul by 2 +# d5: lower 32-bits of fraction for mul by 2 +# d6: temp for bit-field extracts +# d7: byte digit formation word;digit count {0,1} +# a0: pointer into memory for packed bcd string formation +# + + global binstr +binstr: + movm.l &0xff00,-(%sp) # {%d0-%d7} + +# +# A1: Init d7 +# + mov.l &1,%d7 # init d7 for second digit + subq.l &1,%d0 # for dbf d0 would have LEN+1 passes +# +# A2. Copy d2:d3 to d4:d5. Start loop. +# +loop: + mov.l %d2,%d4 # copy the fraction before muls + mov.l %d3,%d5 # to d4:d5 +# +# A3. Multiply d2:d3 by 8; extract msbs into d1. +# + bfextu %d2{&0:&3},%d1 # copy 3 msbs of d2 into d1 + asl.l &3,%d2 # shift d2 left by 3 places + bfextu %d3{&0:&3},%d6 # copy 3 msbs of d3 into d6 + asl.l &3,%d3 # shift d3 left by 3 places + or.l %d6,%d2 # or in msbs from d3 into d2 +# +# A4. Multiply d4:d5 by 2; add carry out to d1. +# + asl.l &1,%d5 # mul d5 by 2 + roxl.l &1,%d4 # mul d4 by 2 + swap %d6 # put 0 in d6 lower word + addx.w %d6,%d1 # add in extend from mul by 2 +# +# A5. Add mul by 8 to mul by 2. D1 contains the digit formed. +# + add.l %d5,%d3 # add lower 32 bits + nop # ERRATA FIX #13 (Rev. 1.2 6/6/90) + addx.l %d4,%d2 # add with extend upper 32 bits + nop # ERRATA FIX #13 (Rev. 1.2 6/6/90) + addx.w %d6,%d1 # add in extend from add to d1 + swap %d6 # with d6 = 0; put 0 in upper word +# +# A6. Test d7 and branch. +# + tst.w %d7 # if zero, store digit & to loop + beq.b first_d # if non-zero, form byte & write +sec_d: + swap %d7 # bring first digit to word d7b + asl.w &4,%d7 # first digit in upper 4 bits d7b + add.w %d1,%d7 # add in ls digit to d7b + mov.b %d7,(%a0)+ # store d7b byte in memory + swap %d7 # put LEN counter in word d7a + clr.w %d7 # set d7a to signal no digits done + dbf.w %d0,loop # do loop some more! + bra.b end_bstr # finished, so exit +first_d: + swap %d7 # put digit word in d7b + mov.w %d1,%d7 # put new digit in d7b + swap %d7 # put LEN counter in word d7a + addq.w &1,%d7 # set d7a to signal first digit done + dbf.w %d0,loop # do loop some more! + swap %d7 # put last digit in string + lsl.w &4,%d7 # move it to upper 4 bits + mov.b %d7,(%a0)+ # store it in memory string +# +# Clean up and return with result in fp0. +# +end_bstr: + movm.l (%sp)+,&0xff # {%d0-%d7} + rts + +######################################################################### +# XDEF **************************************************************** # +# facc_in_b(): dmem_read_byte failed # +# facc_in_w(): dmem_read_word failed # +# facc_in_l(): dmem_read_long failed # +# facc_in_d(): dmem_read of dbl prec failed # +# facc_in_x(): dmem_read of ext prec failed # +# # +# facc_out_b(): dmem_write_byte failed # +# facc_out_w(): dmem_write_word failed # +# facc_out_l(): dmem_write_long failed # +# facc_out_d(): dmem_write of dbl prec failed # +# facc_out_x(): dmem_write of ext prec failed # +# # +# XREF **************************************************************** # +# _real_access() - exit through access error handler # +# # +# INPUT *************************************************************** # +# None # +# # +# OUTPUT ************************************************************** # +# None # +# # +# ALGORITHM *********************************************************** # +# Flow jumps here when an FP data fetch call gets an error # +# result. This means the operating system wants an access error frame # +# made out of the current exception stack frame. # +# So, we first call restore() which makes sure that any updated # +# -(an)+ register gets returned to its pre-exception value and then # +# we change the stack to an access error stack frame. # +# # +######################################################################### + +facc_in_b: + movq.l &0x1,%d0 # one byte + bsr.w restore # fix An + + mov.w &0x0121,EXC_VOFF(%a6) # set FSLW + bra.w facc_finish + +facc_in_w: + movq.l &0x2,%d0 # two bytes + bsr.w restore # fix An + + mov.w &0x0141,EXC_VOFF(%a6) # set FSLW + bra.b facc_finish + +facc_in_l: + movq.l &0x4,%d0 # four bytes + bsr.w restore # fix An + + mov.w &0x0101,EXC_VOFF(%a6) # set FSLW + bra.b facc_finish + +facc_in_d: + movq.l &0x8,%d0 # eight bytes + bsr.w restore # fix An + + mov.w &0x0161,EXC_VOFF(%a6) # set FSLW + bra.b facc_finish + +facc_in_x: + movq.l &0xc,%d0 # twelve bytes + bsr.w restore # fix An + + mov.w &0x0161,EXC_VOFF(%a6) # set FSLW + bra.b facc_finish + +################################################################ + +facc_out_b: + movq.l &0x1,%d0 # one byte + bsr.w restore # restore An + + mov.w &0x00a1,EXC_VOFF(%a6) # set FSLW + bra.b facc_finish + +facc_out_w: + movq.l &0x2,%d0 # two bytes + bsr.w restore # restore An + + mov.w &0x00c1,EXC_VOFF(%a6) # set FSLW + bra.b facc_finish + +facc_out_l: + movq.l &0x4,%d0 # four bytes + bsr.w restore # restore An + + mov.w &0x0081,EXC_VOFF(%a6) # set FSLW + bra.b facc_finish + +facc_out_d: + movq.l &0x8,%d0 # eight bytes + bsr.w restore # restore An + + mov.w &0x00e1,EXC_VOFF(%a6) # set FSLW + bra.b facc_finish + +facc_out_x: + mov.l &0xc,%d0 # twelve bytes + bsr.w restore # restore An + + mov.w &0x00e1,EXC_VOFF(%a6) # set FSLW + +# here's where we actually create the access error frame from the +# current exception stack frame. +facc_finish: + mov.l USER_FPIAR(%a6),EXC_PC(%a6) # store current PC + + fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 + fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs + movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 + + unlk %a6 + + mov.l (%sp),-(%sp) # store SR, hi(PC) + mov.l 0x8(%sp),0x4(%sp) # store lo(PC) + mov.l 0xc(%sp),0x8(%sp) # store EA + mov.l &0x00000001,0xc(%sp) # store FSLW + mov.w 0x6(%sp),0xc(%sp) # fix FSLW (size) + mov.w &0x4008,0x6(%sp) # store voff + + btst &0x5,(%sp) # supervisor or user mode? + beq.b facc_out2 # user + bset &0x2,0xd(%sp) # set supervisor TM bit + +facc_out2: + bra.l _real_access + +################################################################## + +# if the effective addressing mode was predecrement or postincrement, +# the emulation has already changed its value to the correct post- +# instruction value. but since we're exiting to the access error +# handler, then AN must be returned to its pre-instruction value. +# we do that here. +restore: + mov.b EXC_OPWORD+0x1(%a6),%d1 + andi.b &0x38,%d1 # extract opmode + cmpi.b %d1,&0x18 # postinc? + beq.w rest_inc + cmpi.b %d1,&0x20 # predec? + beq.w rest_dec + rts + +rest_inc: + mov.b EXC_OPWORD+0x1(%a6),%d1 + andi.w &0x0007,%d1 # fetch An + + mov.w (tbl_rest_inc.b,%pc,%d1.w*2),%d1 + jmp (tbl_rest_inc.b,%pc,%d1.w*1) + +tbl_rest_inc: + short ri_a0 - tbl_rest_inc + short ri_a1 - tbl_rest_inc + short ri_a2 - tbl_rest_inc + short ri_a3 - tbl_rest_inc + short ri_a4 - tbl_rest_inc + short ri_a5 - tbl_rest_inc + short ri_a6 - tbl_rest_inc + short ri_a7 - tbl_rest_inc + +ri_a0: + sub.l %d0,EXC_DREGS+0x8(%a6) # fix stacked a0 + rts +ri_a1: + sub.l %d0,EXC_DREGS+0xc(%a6) # fix stacked a1 + rts +ri_a2: + sub.l %d0,%a2 # fix a2 + rts +ri_a3: + sub.l %d0,%a3 # fix a3 + rts +ri_a4: + sub.l %d0,%a4 # fix a4 + rts +ri_a5: + sub.l %d0,%a5 # fix a5 + rts +ri_a6: + sub.l %d0,(%a6) # fix stacked a6 + rts +# if it's a fmove out instruction, we don't have to fix a7 +# because we hadn't changed it yet. if it's an opclass two +# instruction (data moved in) and the exception was in supervisor +# mode, then also also wasn't updated. if it was user mode, then +# restore the correct a7 which is in the USP currently. +ri_a7: + cmpi.b EXC_VOFF(%a6),&0x30 # move in or out? + bne.b ri_a7_done # out + + btst &0x5,EXC_SR(%a6) # user or supervisor? + bne.b ri_a7_done # supervisor + movc %usp,%a0 # restore USP + sub.l %d0,%a0 + movc %a0,%usp +ri_a7_done: + rts + +# need to invert adjustment value if the <ea> was predec +rest_dec: + neg.l %d0 + bra.b rest_inc |