fpu_aux.c (5508B)
1// SPDX-License-Identifier: GPL-2.0 2/*---------------------------------------------------------------------------+ 3 | fpu_aux.c | 4 | | 5 | Code to implement some of the FPU auxiliary instructions. | 6 | | 7 | Copyright (C) 1992,1993,1994,1997 | 8 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | 9 | E-mail billm@suburbia.net | 10 | | 11 | | 12 +---------------------------------------------------------------------------*/ 13 14#include "fpu_system.h" 15#include "exception.h" 16#include "fpu_emu.h" 17#include "status_w.h" 18#include "control_w.h" 19 20static void fnop(void) 21{ 22} 23 24static void fclex(void) 25{ 26 partial_status &= 27 ~(SW_Backward | SW_Summary | SW_Stack_Fault | SW_Precision | 28 SW_Underflow | SW_Overflow | SW_Zero_Div | SW_Denorm_Op | 29 SW_Invalid); 30 no_ip_update = 1; 31} 32 33/* Needs to be externally visible */ 34void fpstate_init_soft(struct swregs_state *soft) 35{ 36 struct address *oaddr, *iaddr; 37 memset(soft, 0, sizeof(*soft)); 38 soft->cwd = 0x037f; 39 soft->swd = 0; 40 soft->ftop = 0; /* We don't keep top in the status word internally. */ 41 soft->twd = 0xffff; 42 /* The behaviour is different from that detailed in 43 Section 15.1.6 of the Intel manual */ 44 oaddr = (struct address *)&soft->foo; 45 oaddr->offset = 0; 46 oaddr->selector = 0; 47 iaddr = (struct address *)&soft->fip; 48 iaddr->offset = 0; 49 iaddr->selector = 0; 50 iaddr->opcode = 0; 51 soft->no_update = 1; 52} 53 54void finit(void) 55{ 56 fpstate_init_soft(¤t->thread.fpu.fpstate->regs.soft); 57} 58 59/* 60 * These are nops on the i387.. 61 */ 62#define feni fnop 63#define fdisi fnop 64#define fsetpm fnop 65 66static FUNC const finit_table[] = { 67 feni, fdisi, fclex, finit, 68 fsetpm, FPU_illegal, FPU_illegal, FPU_illegal 69}; 70 71void finit_(void) 72{ 73 (finit_table[FPU_rm]) (); 74} 75 76static void fstsw_ax(void) 77{ 78 *(short *)&FPU_EAX = status_word(); 79 no_ip_update = 1; 80} 81 82static FUNC const fstsw_table[] = { 83 fstsw_ax, FPU_illegal, FPU_illegal, FPU_illegal, 84 FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal 85}; 86 87void fstsw_(void) 88{ 89 (fstsw_table[FPU_rm]) (); 90} 91 92static FUNC const fp_nop_table[] = { 93 fnop, FPU_illegal, FPU_illegal, FPU_illegal, 94 FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal 95}; 96 97void fp_nop(void) 98{ 99 (fp_nop_table[FPU_rm]) (); 100} 101 102void fld_i_(void) 103{ 104 FPU_REG *st_new_ptr; 105 int i; 106 u_char tag; 107 108 if (STACK_OVERFLOW) { 109 FPU_stack_overflow(); 110 return; 111 } 112 113 /* fld st(i) */ 114 i = FPU_rm; 115 if (NOT_EMPTY(i)) { 116 reg_copy(&st(i), st_new_ptr); 117 tag = FPU_gettagi(i); 118 push(); 119 FPU_settag0(tag); 120 } else { 121 if (control_word & CW_Invalid) { 122 /* The masked response */ 123 FPU_stack_underflow(); 124 } else 125 EXCEPTION(EX_StackUnder); 126 } 127 128} 129 130void fxch_i(void) 131{ 132 /* fxch st(i) */ 133 FPU_REG t; 134 int i = FPU_rm; 135 FPU_REG *st0_ptr = &st(0), *sti_ptr = &st(i); 136 long tag_word = fpu_tag_word; 137 int regnr = top & 7, regnri = ((regnr + i) & 7); 138 u_char st0_tag = (tag_word >> (regnr * 2)) & 3; 139 u_char sti_tag = (tag_word >> (regnri * 2)) & 3; 140 141 if (st0_tag == TAG_Empty) { 142 if (sti_tag == TAG_Empty) { 143 FPU_stack_underflow(); 144 FPU_stack_underflow_i(i); 145 return; 146 } 147 if (control_word & CW_Invalid) { 148 /* Masked response */ 149 FPU_copy_to_reg0(sti_ptr, sti_tag); 150 } 151 FPU_stack_underflow_i(i); 152 return; 153 } 154 if (sti_tag == TAG_Empty) { 155 if (control_word & CW_Invalid) { 156 /* Masked response */ 157 FPU_copy_to_regi(st0_ptr, st0_tag, i); 158 } 159 FPU_stack_underflow(); 160 return; 161 } 162 clear_C1(); 163 164 reg_copy(st0_ptr, &t); 165 reg_copy(sti_ptr, st0_ptr); 166 reg_copy(&t, sti_ptr); 167 168 tag_word &= ~(3 << (regnr * 2)) & ~(3 << (regnri * 2)); 169 tag_word |= (sti_tag << (regnr * 2)) | (st0_tag << (regnri * 2)); 170 fpu_tag_word = tag_word; 171} 172 173static void fcmovCC(void) 174{ 175 /* fcmovCC st(i) */ 176 int i = FPU_rm; 177 FPU_REG *st0_ptr = &st(0); 178 FPU_REG *sti_ptr = &st(i); 179 long tag_word = fpu_tag_word; 180 int regnr = top & 7; 181 int regnri = (top + i) & 7; 182 u_char sti_tag = (tag_word >> (regnri * 2)) & 3; 183 184 if (sti_tag == TAG_Empty) { 185 FPU_stack_underflow(); 186 clear_C1(); 187 return; 188 } 189 reg_copy(sti_ptr, st0_ptr); 190 tag_word &= ~(3 << (regnr * 2)); 191 tag_word |= (sti_tag << (regnr * 2)); 192 fpu_tag_word = tag_word; 193} 194 195void fcmovb(void) 196{ 197 if (FPU_EFLAGS & X86_EFLAGS_CF) 198 fcmovCC(); 199} 200 201void fcmove(void) 202{ 203 if (FPU_EFLAGS & X86_EFLAGS_ZF) 204 fcmovCC(); 205} 206 207void fcmovbe(void) 208{ 209 if (FPU_EFLAGS & (X86_EFLAGS_CF|X86_EFLAGS_ZF)) 210 fcmovCC(); 211} 212 213void fcmovu(void) 214{ 215 if (FPU_EFLAGS & X86_EFLAGS_PF) 216 fcmovCC(); 217} 218 219void fcmovnb(void) 220{ 221 if (!(FPU_EFLAGS & X86_EFLAGS_CF)) 222 fcmovCC(); 223} 224 225void fcmovne(void) 226{ 227 if (!(FPU_EFLAGS & X86_EFLAGS_ZF)) 228 fcmovCC(); 229} 230 231void fcmovnbe(void) 232{ 233 if (!(FPU_EFLAGS & (X86_EFLAGS_CF|X86_EFLAGS_ZF))) 234 fcmovCC(); 235} 236 237void fcmovnu(void) 238{ 239 if (!(FPU_EFLAGS & X86_EFLAGS_PF)) 240 fcmovCC(); 241} 242 243void ffree_(void) 244{ 245 /* ffree st(i) */ 246 FPU_settagi(FPU_rm, TAG_Empty); 247} 248 249void ffreep(void) 250{ 251 /* ffree st(i) + pop - unofficial code */ 252 FPU_settagi(FPU_rm, TAG_Empty); 253 FPU_pop(); 254} 255 256void fst_i_(void) 257{ 258 /* fst st(i) */ 259 FPU_copy_to_regi(&st(0), FPU_gettag0(), FPU_rm); 260} 261 262void fstp_i(void) 263{ 264 /* fstp st(i) */ 265 FPU_copy_to_regi(&st(0), FPU_gettag0(), FPU_rm); 266 FPU_pop(); 267}