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Diffstat (limited to '')
| -rw-r--r-- | arch/x86/math-emu/fpu_aux.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/arch/x86/math-emu/fpu_aux.c b/arch/x86/math-emu/fpu_aux.c new file mode 100644 index 000000000..034748459 --- /dev/null +++ b/arch/x86/math-emu/fpu_aux.c @@ -0,0 +1,267 @@ +// SPDX-License-Identifier: GPL-2.0 +/*---------------------------------------------------------------------------+ + | fpu_aux.c | + | | + | Code to implement some of the FPU auxiliary instructions. | + | | + | Copyright (C) 1992,1993,1994,1997 | + | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | + | E-mail billm@suburbia.net | + | | + | | + +---------------------------------------------------------------------------*/ + +#include "fpu_system.h" +#include "exception.h" +#include "fpu_emu.h" +#include "status_w.h" +#include "control_w.h" + +static void fnop(void) +{ +} + +static void fclex(void) +{ + partial_status &= + ~(SW_Backward | SW_Summary | SW_Stack_Fault | SW_Precision | + SW_Underflow | SW_Overflow | SW_Zero_Div | SW_Denorm_Op | + SW_Invalid); + no_ip_update = 1; +} + +/* Needs to be externally visible */ +void fpstate_init_soft(struct swregs_state *soft) +{ + struct address *oaddr, *iaddr; + memset(soft, 0, sizeof(*soft)); + soft->cwd = 0x037f; + soft->swd = 0; + soft->ftop = 0; /* We don't keep top in the status word internally. */ + soft->twd = 0xffff; + /* The behaviour is different from that detailed in + Section 15.1.6 of the Intel manual */ + oaddr = (struct address *)&soft->foo; + oaddr->offset = 0; + oaddr->selector = 0; + iaddr = (struct address *)&soft->fip; + iaddr->offset = 0; + iaddr->selector = 0; + iaddr->opcode = 0; + soft->no_update = 1; +} + +void finit(void) +{ + fpstate_init_soft(¤t->thread.fpu.state.soft); +} + +/* + * These are nops on the i387.. + */ +#define feni fnop +#define fdisi fnop +#define fsetpm fnop + +static FUNC const finit_table[] = { + feni, fdisi, fclex, finit, + fsetpm, FPU_illegal, FPU_illegal, FPU_illegal +}; + +void finit_(void) +{ + (finit_table[FPU_rm]) (); +} + +static void fstsw_ax(void) +{ + *(short *)&FPU_EAX = status_word(); + no_ip_update = 1; +} + +static FUNC const fstsw_table[] = { + fstsw_ax, FPU_illegal, FPU_illegal, FPU_illegal, + FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal +}; + +void fstsw_(void) +{ + (fstsw_table[FPU_rm]) (); +} + +static FUNC const fp_nop_table[] = { + fnop, FPU_illegal, FPU_illegal, FPU_illegal, + FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal +}; + +void fp_nop(void) +{ + (fp_nop_table[FPU_rm]) (); +} + +void fld_i_(void) +{ + FPU_REG *st_new_ptr; + int i; + u_char tag; + + if (STACK_OVERFLOW) { + FPU_stack_overflow(); + return; + } + + /* fld st(i) */ + i = FPU_rm; + if (NOT_EMPTY(i)) { + reg_copy(&st(i), st_new_ptr); + tag = FPU_gettagi(i); + push(); + FPU_settag0(tag); + } else { + if (control_word & CW_Invalid) { + /* The masked response */ + FPU_stack_underflow(); + } else + EXCEPTION(EX_StackUnder); + } + +} + +void fxch_i(void) +{ + /* fxch st(i) */ + FPU_REG t; + int i = FPU_rm; + FPU_REG *st0_ptr = &st(0), *sti_ptr = &st(i); + long tag_word = fpu_tag_word; + int regnr = top & 7, regnri = ((regnr + i) & 7); + u_char st0_tag = (tag_word >> (regnr * 2)) & 3; + u_char sti_tag = (tag_word >> (regnri * 2)) & 3; + + if (st0_tag == TAG_Empty) { + if (sti_tag == TAG_Empty) { + FPU_stack_underflow(); + FPU_stack_underflow_i(i); + return; + } + if (control_word & CW_Invalid) { + /* Masked response */ + FPU_copy_to_reg0(sti_ptr, sti_tag); + } + FPU_stack_underflow_i(i); + return; + } + if (sti_tag == TAG_Empty) { + if (control_word & CW_Invalid) { + /* Masked response */ + FPU_copy_to_regi(st0_ptr, st0_tag, i); + } + FPU_stack_underflow(); + return; + } + clear_C1(); + + reg_copy(st0_ptr, &t); + reg_copy(sti_ptr, st0_ptr); + reg_copy(&t, sti_ptr); + + tag_word &= ~(3 << (regnr * 2)) & ~(3 << (regnri * 2)); + tag_word |= (sti_tag << (regnr * 2)) | (st0_tag << (regnri * 2)); + fpu_tag_word = tag_word; +} + +static void fcmovCC(void) +{ + /* fcmovCC st(i) */ + int i = FPU_rm; + FPU_REG *st0_ptr = &st(0); + FPU_REG *sti_ptr = &st(i); + long tag_word = fpu_tag_word; + int regnr = top & 7; + int regnri = (top + i) & 7; + u_char sti_tag = (tag_word >> (regnri * 2)) & 3; + + if (sti_tag == TAG_Empty) { + FPU_stack_underflow(); + clear_C1(); + return; + } + reg_copy(sti_ptr, st0_ptr); + tag_word &= ~(3 << (regnr * 2)); + tag_word |= (sti_tag << (regnr * 2)); + fpu_tag_word = tag_word; +} + +void fcmovb(void) +{ + if (FPU_EFLAGS & X86_EFLAGS_CF) + fcmovCC(); +} + +void fcmove(void) +{ + if (FPU_EFLAGS & X86_EFLAGS_ZF) + fcmovCC(); +} + +void fcmovbe(void) +{ + if (FPU_EFLAGS & (X86_EFLAGS_CF|X86_EFLAGS_ZF)) + fcmovCC(); +} + +void fcmovu(void) +{ + if (FPU_EFLAGS & X86_EFLAGS_PF) + fcmovCC(); +} + +void fcmovnb(void) +{ + if (!(FPU_EFLAGS & X86_EFLAGS_CF)) + fcmovCC(); +} + +void fcmovne(void) +{ + if (!(FPU_EFLAGS & X86_EFLAGS_ZF)) + fcmovCC(); +} + +void fcmovnbe(void) +{ + if (!(FPU_EFLAGS & (X86_EFLAGS_CF|X86_EFLAGS_ZF))) + fcmovCC(); +} + +void fcmovnu(void) +{ + if (!(FPU_EFLAGS & X86_EFLAGS_PF)) + fcmovCC(); +} + +void ffree_(void) +{ + /* ffree st(i) */ + FPU_settagi(FPU_rm, TAG_Empty); +} + +void ffreep(void) +{ + /* ffree st(i) + pop - unofficial code */ + FPU_settagi(FPU_rm, TAG_Empty); + FPU_pop(); +} + +void fst_i_(void) +{ + /* fst st(i) */ + FPU_copy_to_regi(&st(0), FPU_gettag0(), FPU_rm); +} + +void fstp_i(void) +{ + /* fstp st(i) */ + FPU_copy_to_regi(&st(0), FPU_gettag0(), FPU_rm); + FPU_pop(); +} |