diff options
Diffstat (limited to 'arch/x86/math-emu/fpu_tags.c')
-rw-r--r-- | arch/x86/math-emu/fpu_tags.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/x86/math-emu/fpu_tags.c b/arch/x86/math-emu/fpu_tags.c new file mode 100644 index 0000000000..bff95d4e7d --- /dev/null +++ b/arch/x86/math-emu/fpu_tags.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0 +/*---------------------------------------------------------------------------+ + | fpu_tags.c | + | | + | Set FPU register tags. | + | | + | Copyright (C) 1997 | + | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | + | E-mail billm@jacobi.maths.monash.edu.au | + | | + | | + +---------------------------------------------------------------------------*/ + +#include "fpu_emu.h" +#include "fpu_system.h" +#include "exception.h" + +void FPU_pop(void) +{ + fpu_tag_word |= 3 << ((top & 7) * 2); + top++; +} + +int FPU_gettag0(void) +{ + return (fpu_tag_word >> ((top & 7) * 2)) & 3; +} + +int FPU_gettagi(int stnr) +{ + return (fpu_tag_word >> (((top + stnr) & 7) * 2)) & 3; +} + +int FPU_gettag(int regnr) +{ + return (fpu_tag_word >> ((regnr & 7) * 2)) & 3; +} + +void FPU_settag0(int tag) +{ + int regnr = top; + regnr &= 7; + fpu_tag_word &= ~(3 << (regnr * 2)); + fpu_tag_word |= (tag & 3) << (regnr * 2); +} + +void FPU_settagi(int stnr, int tag) +{ + int regnr = stnr + top; + regnr &= 7; + fpu_tag_word &= ~(3 << (regnr * 2)); + fpu_tag_word |= (tag & 3) << (regnr * 2); +} + +void FPU_settag(int regnr, int tag) +{ + regnr &= 7; + fpu_tag_word &= ~(3 << (regnr * 2)); + fpu_tag_word |= (tag & 3) << (regnr * 2); +} + +int FPU_Special(FPU_REG const *ptr) +{ + int exp = exponent(ptr); + + if (exp == EXP_BIAS + EXP_UNDER) + return TW_Denormal; + else if (exp != EXP_BIAS + EXP_OVER) + return TW_NaN; + else if ((ptr->sigh == 0x80000000) && (ptr->sigl == 0)) + return TW_Infinity; + return TW_NaN; +} + +int isNaN(FPU_REG const *ptr) +{ + return ((exponent(ptr) == EXP_BIAS + EXP_OVER) + && !((ptr->sigh == 0x80000000) && (ptr->sigl == 0))); +} + +int FPU_empty_i(int stnr) +{ + int regnr = (top + stnr) & 7; + + return ((fpu_tag_word >> (regnr * 2)) & 3) == TAG_Empty; +} + +int FPU_stackoverflow(FPU_REG ** st_new_ptr) +{ + *st_new_ptr = &st(-1); + + return ((fpu_tag_word >> (((top - 1) & 7) * 2)) & 3) != TAG_Empty; +} + +void FPU_copy_to_regi(FPU_REG const *r, u_char tag, int stnr) +{ + reg_copy(r, &st(stnr)); + FPU_settagi(stnr, tag); +} + +void FPU_copy_to_reg1(FPU_REG const *r, u_char tag) +{ + reg_copy(r, &st(1)); + FPU_settagi(1, tag); +} + +void FPU_copy_to_reg0(FPU_REG const *r, u_char tag) +{ + int regnr = top; + regnr &= 7; + + reg_copy(r, &st(0)); + + fpu_tag_word &= ~(3 << (regnr * 2)); + fpu_tag_word |= (tag & 3) << (regnr * 2); +} |