1 // SPDX-License-Identifier: GPL-2.0 2 /*---------------------------------------------------------------------------+ 3 | fpu_tags.c | 4 | | 5 | Set FPU register tags. | 6 | | 7 | Copyright (C) 1997 | 8 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | 9 | E-mail billm@jacobi.maths.monash.edu.au | 10 | | 11 | | 12 +---------------------------------------------------------------------------*/ 13 14 #include "fpu_emu.h" 15 #include "fpu_system.h" 16 #include "exception.h" 17 18 void FPU_pop(void) 19 { 20 fpu_tag_word |= 3 << ((top & 7) * 2); 21 top++; 22 } 23 24 int FPU_gettag0(void) 25 { 26 return (fpu_tag_word >> ((top & 7) * 2)) & 3; 27 } 28 29 int FPU_gettagi(int stnr) 30 { 31 return (fpu_tag_word >> (((top + stnr) & 7) * 2)) & 3; 32 } 33 34 int FPU_gettag(int regnr) 35 { 36 return (fpu_tag_word >> ((regnr & 7) * 2)) & 3; 37 } 38 39 void FPU_settag0(int tag) 40 { 41 int regnr = top; 42 regnr &= 7; 43 fpu_tag_word &= ~(3 << (regnr * 2)); 44 fpu_tag_word |= (tag & 3) << (regnr * 2); 45 } 46 47 void FPU_settagi(int stnr, int tag) 48 { 49 int regnr = stnr + top; 50 regnr &= 7; 51 fpu_tag_word &= ~(3 << (regnr * 2)); 52 fpu_tag_word |= (tag & 3) << (regnr * 2); 53 } 54 55 void FPU_settag(int regnr, int tag) 56 { 57 regnr &= 7; 58 fpu_tag_word &= ~(3 << (regnr * 2)); 59 fpu_tag_word |= (tag & 3) << (regnr * 2); 60 } 61 62 int FPU_Special(FPU_REG const *ptr) 63 { 64 int exp = exponent(ptr); 65 66 if (exp == EXP_BIAS + EXP_UNDER) 67 return TW_Denormal; 68 else if (exp != EXP_BIAS + EXP_OVER) 69 return TW_NaN; 70 else if ((ptr->sigh == 0x80000000) && (ptr->sigl == 0)) 71 return TW_Infinity; 72 return TW_NaN; 73 } 74 75 int isNaN(FPU_REG const *ptr) 76 { 77 return ((exponent(ptr) == EXP_BIAS + EXP_OVER) 78 && !((ptr->sigh == 0x80000000) && (ptr->sigl == 0))); 79 } 80 81 int FPU_empty_i(int stnr) 82 { 83 int regnr = (top + stnr) & 7; 84 85 return ((fpu_tag_word >> (regnr * 2)) & 3) == TAG_Empty; 86 } 87 88 int FPU_stackoverflow(FPU_REG ** st_new_ptr) 89 { 90 *st_new_ptr = &st(-1); 91 92 return ((fpu_tag_word >> (((top - 1) & 7) * 2)) & 3) != TAG_Empty; 93 } 94 95 void FPU_copy_to_regi(FPU_REG const *r, u_char tag, int stnr) 96 { 97 reg_copy(r, &st(stnr)); 98 FPU_settagi(stnr, tag); 99 } 100 101 void FPU_copy_to_reg1(FPU_REG const *r, u_char tag) 102 { 103 reg_copy(r, &st(1)); 104 FPU_settagi(1, tag); 105 } 106 107 void FPU_copy_to_reg0(FPU_REG const *r, u_char tag) 108 { 109 int regnr = top; 110 regnr &= 7; 111 112 reg_copy(r, &st(0)); 113 114 fpu_tag_word &= ~(3 << (regnr * 2)); 115 fpu_tag_word |= (tag & 3) << (regnr * 2); 116 } 117