1/*---------------------------------------------------------------------------+ 2 | fpu_tags.c | 3 | | 4 | Set FPU register tags. | 5 | | 6 | Copyright (C) 1997 | 7 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | 8 | E-mail billm@jacobi.maths.monash.edu.au | 9 | | 10 | | 11 +---------------------------------------------------------------------------*/ 12 13#include "fpu_emu.h" 14#include "fpu_system.h" 15#include "exception.h" 16 17void FPU_pop(void) 18{ 19 fpu_tag_word |= 3 << ((top & 7) * 2); 20 top++; 21} 22 23int FPU_gettag0(void) 24{ 25 return (fpu_tag_word >> ((top & 7) * 2)) & 3; 26} 27 28int FPU_gettagi(int stnr) 29{ 30 return (fpu_tag_word >> (((top + stnr) & 7) * 2)) & 3; 31} 32 33int FPU_gettag(int regnr) 34{ 35 return (fpu_tag_word >> ((regnr & 7) * 2)) & 3; 36} 37 38void FPU_settag0(int tag) 39{ 40 int regnr = top; 41 regnr &= 7; 42 fpu_tag_word &= ~(3 << (regnr * 2)); 43 fpu_tag_word |= (tag & 3) << (regnr * 2); 44} 45 46void FPU_settagi(int stnr, int tag) 47{ 48 int regnr = stnr + top; 49 regnr &= 7; 50 fpu_tag_word &= ~(3 << (regnr * 2)); 51 fpu_tag_word |= (tag & 3) << (regnr * 2); 52} 53 54void FPU_settag(int regnr, int tag) 55{ 56 regnr &= 7; 57 fpu_tag_word &= ~(3 << (regnr * 2)); 58 fpu_tag_word |= (tag & 3) << (regnr * 2); 59} 60 61int FPU_Special(FPU_REG const *ptr) 62{ 63 int exp = exponent(ptr); 64 65 if (exp == EXP_BIAS + EXP_UNDER) 66 return TW_Denormal; 67 else if (exp != EXP_BIAS + EXP_OVER) 68 return TW_NaN; 69 else if ((ptr->sigh == 0x80000000) && (ptr->sigl == 0)) 70 return TW_Infinity; 71 return TW_NaN; 72} 73 74int isNaN(FPU_REG const *ptr) 75{ 76 return ((exponent(ptr) == EXP_BIAS + EXP_OVER) 77 && !((ptr->sigh == 0x80000000) && (ptr->sigl == 0))); 78} 79 80int FPU_empty_i(int stnr) 81{ 82 int regnr = (top + stnr) & 7; 83 84 return ((fpu_tag_word >> (regnr * 2)) & 3) == TAG_Empty; 85} 86 87int FPU_stackoverflow(FPU_REG ** st_new_ptr) 88{ 89 *st_new_ptr = &st(-1); 90 91 return ((fpu_tag_word >> (((top - 1) & 7) * 2)) & 3) != TAG_Empty; 92} 93 94void FPU_copy_to_regi(FPU_REG const *r, u_char tag, int stnr) 95{ 96 reg_copy(r, &st(stnr)); 97 FPU_settagi(stnr, tag); 98} 99 100void FPU_copy_to_reg1(FPU_REG const *r, u_char tag) 101{ 102 reg_copy(r, &st(1)); 103 FPU_settagi(1, tag); 104} 105 106void FPU_copy_to_reg0(FPU_REG const *r, u_char tag) 107{ 108 int regnr = top; 109 regnr &= 7; 110 111 reg_copy(r, &st(0)); 112 113 fpu_tag_word &= ~(3 << (regnr * 2)); 114 fpu_tag_word |= (tag & 3) << (regnr * 2); 115} 116