x86_flags.c (9753B)
1///////////////////////////////////////////////////////////////////////// 2// 3// Copyright (C) 2001-2012 The Bochs Project 4// Copyright (C) 2017 Google Inc. 5// 6// This library is free software; you can redistribute it and/or 7// modify it under the terms of the GNU Lesser General Public 8// License as published by the Free Software Foundation; either 9// version 2.1 of the License, or (at your option) any later version. 10// 11// This library is distributed in the hope that it will be useful, 12// but WITHOUT ANY WARRANTY; without even the implied warranty of 13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14// Lesser General Public License for more details. 15// 16// You should have received a copy of the GNU Lesser General Public 17// License along with this library; if not, write to the Free Software 18// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA 19///////////////////////////////////////////////////////////////////////// 20/* 21 * flags functions 22 */ 23 24#include "qemu/osdep.h" 25 26#include "qemu-common.h" 27#include "panic.h" 28#include "cpu.h" 29#include "x86_flags.h" 30#include "x86.h" 31 32 33/* this is basically bocsh code */ 34 35#define LF_SIGN_BIT 31 36 37#define LF_BIT_SD (0) /* lazy Sign Flag Delta */ 38#define LF_BIT_AF (3) /* lazy Adjust flag */ 39#define LF_BIT_PDB (8) /* lazy Parity Delta Byte (8 bits) */ 40#define LF_BIT_CF (31) /* lazy Carry Flag */ 41#define LF_BIT_PO (30) /* lazy Partial Overflow = CF ^ OF */ 42 43#define LF_MASK_SD (0x01 << LF_BIT_SD) 44#define LF_MASK_AF (0x01 << LF_BIT_AF) 45#define LF_MASK_PDB (0xFF << LF_BIT_PDB) 46#define LF_MASK_CF (0x01 << LF_BIT_CF) 47#define LF_MASK_PO (0x01 << LF_BIT_PO) 48 49#define ADD_COUT_VEC(op1, op2, result) \ 50 (((op1) & (op2)) | (((op1) | (op2)) & (~(result)))) 51 52#define SUB_COUT_VEC(op1, op2, result) \ 53 (((~(op1)) & (op2)) | (((~(op1)) ^ (op2)) & (result))) 54 55#define GET_ADD_OVERFLOW(op1, op2, result, mask) \ 56 ((((op1) ^ (result)) & ((op2) ^ (result))) & (mask)) 57 58/* ******************* */ 59/* OSZAPC */ 60/* ******************* */ 61 62/* size, carries, result */ 63#define SET_FLAGS_OSZAPC_SIZE(size, lf_carries, lf_result) { \ 64 target_ulong temp = ((lf_carries) & (LF_MASK_AF)) | \ 65 (((lf_carries) >> (size - 2)) << LF_BIT_PO); \ 66 env->hvf_lflags.result = (target_ulong)(int##size##_t)(lf_result); \ 67 if ((size) == 32) { \ 68 temp = ((lf_carries) & ~(LF_MASK_PDB | LF_MASK_SD)); \ 69 } else if ((size) == 16) { \ 70 temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 16); \ 71 } else if ((size) == 8) { \ 72 temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 24); \ 73 } else { \ 74 VM_PANIC("unimplemented"); \ 75 } \ 76 env->hvf_lflags.auxbits = (target_ulong)(uint32_t)temp; \ 77} 78 79/* carries, result */ 80#define SET_FLAGS_OSZAPC_8(carries, result) \ 81 SET_FLAGS_OSZAPC_SIZE(8, carries, result) 82#define SET_FLAGS_OSZAPC_16(carries, result) \ 83 SET_FLAGS_OSZAPC_SIZE(16, carries, result) 84#define SET_FLAGS_OSZAPC_32(carries, result) \ 85 SET_FLAGS_OSZAPC_SIZE(32, carries, result) 86 87/* ******************* */ 88/* OSZAP */ 89/* ******************* */ 90/* size, carries, result */ 91#define SET_FLAGS_OSZAP_SIZE(size, lf_carries, lf_result) { \ 92 target_ulong temp = ((lf_carries) & (LF_MASK_AF)) | \ 93 (((lf_carries) >> (size - 2)) << LF_BIT_PO); \ 94 if ((size) == 32) { \ 95 temp = ((lf_carries) & ~(LF_MASK_PDB | LF_MASK_SD)); \ 96 } else if ((size) == 16) { \ 97 temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 16); \ 98 } else if ((size) == 8) { \ 99 temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 24); \ 100 } else { \ 101 VM_PANIC("unimplemented"); \ 102 } \ 103 env->hvf_lflags.result = (target_ulong)(int##size##_t)(lf_result); \ 104 target_ulong delta_c = (env->hvf_lflags.auxbits ^ temp) & LF_MASK_CF; \ 105 delta_c ^= (delta_c >> 1); \ 106 env->hvf_lflags.auxbits = (target_ulong)(uint32_t)(temp ^ delta_c); \ 107} 108 109/* carries, result */ 110#define SET_FLAGS_OSZAP_8(carries, result) \ 111 SET_FLAGS_OSZAP_SIZE(8, carries, result) 112#define SET_FLAGS_OSZAP_16(carries, result) \ 113 SET_FLAGS_OSZAP_SIZE(16, carries, result) 114#define SET_FLAGS_OSZAP_32(carries, result) \ 115 SET_FLAGS_OSZAP_SIZE(32, carries, result) 116 117void SET_FLAGS_OxxxxC(CPUX86State *env, uint32_t new_of, uint32_t new_cf) 118{ 119 uint32_t temp_po = new_of ^ new_cf; 120 env->hvf_lflags.auxbits &= ~(LF_MASK_PO | LF_MASK_CF); 121 env->hvf_lflags.auxbits |= (temp_po << LF_BIT_PO) | (new_cf << LF_BIT_CF); 122} 123 124void SET_FLAGS_OSZAPC_SUB32(CPUX86State *env, uint32_t v1, uint32_t v2, 125 uint32_t diff) 126{ 127 SET_FLAGS_OSZAPC_32(SUB_COUT_VEC(v1, v2, diff), diff); 128} 129 130void SET_FLAGS_OSZAPC_SUB16(CPUX86State *env, uint16_t v1, uint16_t v2, 131 uint16_t diff) 132{ 133 SET_FLAGS_OSZAPC_16(SUB_COUT_VEC(v1, v2, diff), diff); 134} 135 136void SET_FLAGS_OSZAPC_SUB8(CPUX86State *env, uint8_t v1, uint8_t v2, 137 uint8_t diff) 138{ 139 SET_FLAGS_OSZAPC_8(SUB_COUT_VEC(v1, v2, diff), diff); 140} 141 142void SET_FLAGS_OSZAPC_ADD32(CPUX86State *env, uint32_t v1, uint32_t v2, 143 uint32_t diff) 144{ 145 SET_FLAGS_OSZAPC_32(ADD_COUT_VEC(v1, v2, diff), diff); 146} 147 148void SET_FLAGS_OSZAPC_ADD16(CPUX86State *env, uint16_t v1, uint16_t v2, 149 uint16_t diff) 150{ 151 SET_FLAGS_OSZAPC_16(ADD_COUT_VEC(v1, v2, diff), diff); 152} 153 154void SET_FLAGS_OSZAPC_ADD8(CPUX86State *env, uint8_t v1, uint8_t v2, 155 uint8_t diff) 156{ 157 SET_FLAGS_OSZAPC_8(ADD_COUT_VEC(v1, v2, diff), diff); 158} 159 160void SET_FLAGS_OSZAP_SUB32(CPUX86State *env, uint32_t v1, uint32_t v2, 161 uint32_t diff) 162{ 163 SET_FLAGS_OSZAP_32(SUB_COUT_VEC(v1, v2, diff), diff); 164} 165 166void SET_FLAGS_OSZAP_SUB16(CPUX86State *env, uint16_t v1, uint16_t v2, 167 uint16_t diff) 168{ 169 SET_FLAGS_OSZAP_16(SUB_COUT_VEC(v1, v2, diff), diff); 170} 171 172void SET_FLAGS_OSZAP_SUB8(CPUX86State *env, uint8_t v1, uint8_t v2, 173 uint8_t diff) 174{ 175 SET_FLAGS_OSZAP_8(SUB_COUT_VEC(v1, v2, diff), diff); 176} 177 178void SET_FLAGS_OSZAP_ADD32(CPUX86State *env, uint32_t v1, uint32_t v2, 179 uint32_t diff) 180{ 181 SET_FLAGS_OSZAP_32(ADD_COUT_VEC(v1, v2, diff), diff); 182} 183 184void SET_FLAGS_OSZAP_ADD16(CPUX86State *env, uint16_t v1, uint16_t v2, 185 uint16_t diff) 186{ 187 SET_FLAGS_OSZAP_16(ADD_COUT_VEC(v1, v2, diff), diff); 188} 189 190void SET_FLAGS_OSZAP_ADD8(CPUX86State *env, uint8_t v1, uint8_t v2, 191 uint8_t diff) 192{ 193 SET_FLAGS_OSZAP_8(ADD_COUT_VEC(v1, v2, diff), diff); 194} 195 196 197void SET_FLAGS_OSZAPC_LOGIC32(CPUX86State *env, uint32_t v1, uint32_t v2, 198 uint32_t diff) 199{ 200 SET_FLAGS_OSZAPC_32(0, diff); 201} 202 203void SET_FLAGS_OSZAPC_LOGIC16(CPUX86State *env, uint16_t v1, uint16_t v2, 204 uint16_t diff) 205{ 206 SET_FLAGS_OSZAPC_16(0, diff); 207} 208 209void SET_FLAGS_OSZAPC_LOGIC8(CPUX86State *env, uint8_t v1, uint8_t v2, 210 uint8_t diff) 211{ 212 SET_FLAGS_OSZAPC_8(0, diff); 213} 214 215bool get_PF(CPUX86State *env) 216{ 217 uint32_t temp = (255 & env->hvf_lflags.result); 218 temp = temp ^ (255 & (env->hvf_lflags.auxbits >> LF_BIT_PDB)); 219 temp = (temp ^ (temp >> 4)) & 0x0F; 220 return (0x9669U >> temp) & 1; 221} 222 223void set_PF(CPUX86State *env, bool val) 224{ 225 uint32_t temp = (255 & env->hvf_lflags.result) ^ (!val); 226 env->hvf_lflags.auxbits &= ~(LF_MASK_PDB); 227 env->hvf_lflags.auxbits |= (temp << LF_BIT_PDB); 228} 229 230bool get_OF(CPUX86State *env) 231{ 232 return ((env->hvf_lflags.auxbits + (1U << LF_BIT_PO)) >> LF_BIT_CF) & 1; 233} 234 235bool get_CF(CPUX86State *env) 236{ 237 return (env->hvf_lflags.auxbits >> LF_BIT_CF) & 1; 238} 239 240void set_OF(CPUX86State *env, bool val) 241{ 242 bool old_cf = get_CF(env); 243 SET_FLAGS_OxxxxC(env, val, old_cf); 244} 245 246void set_CF(CPUX86State *env, bool val) 247{ 248 bool old_of = get_OF(env); 249 SET_FLAGS_OxxxxC(env, old_of, val); 250} 251 252bool get_AF(CPUX86State *env) 253{ 254 return (env->hvf_lflags.auxbits >> LF_BIT_AF) & 1; 255} 256 257void set_AF(CPUX86State *env, bool val) 258{ 259 env->hvf_lflags.auxbits &= ~(LF_MASK_AF); 260 env->hvf_lflags.auxbits |= val << LF_BIT_AF; 261} 262 263bool get_ZF(CPUX86State *env) 264{ 265 return !env->hvf_lflags.result; 266} 267 268void set_ZF(CPUX86State *env, bool val) 269{ 270 if (val) { 271 env->hvf_lflags.auxbits ^= 272 (((env->hvf_lflags.result >> LF_SIGN_BIT) & 1) << LF_BIT_SD); 273 /* merge the parity bits into the Parity Delta Byte */ 274 uint32_t temp_pdb = (255 & env->hvf_lflags.result); 275 env->hvf_lflags.auxbits ^= (temp_pdb << LF_BIT_PDB); 276 /* now zero the .result value */ 277 env->hvf_lflags.result = 0; 278 } else { 279 env->hvf_lflags.result |= (1 << 8); 280 } 281} 282 283bool get_SF(CPUX86State *env) 284{ 285 return ((env->hvf_lflags.result >> LF_SIGN_BIT) ^ 286 (env->hvf_lflags.auxbits >> LF_BIT_SD)) & 1; 287} 288 289void set_SF(CPUX86State *env, bool val) 290{ 291 bool temp_sf = get_SF(env); 292 env->hvf_lflags.auxbits ^= (temp_sf ^ val) << LF_BIT_SD; 293} 294 295void lflags_to_rflags(CPUX86State *env) 296{ 297 env->eflags |= get_CF(env) ? CC_C : 0; 298 env->eflags |= get_PF(env) ? CC_P : 0; 299 env->eflags |= get_AF(env) ? CC_A : 0; 300 env->eflags |= get_ZF(env) ? CC_Z : 0; 301 env->eflags |= get_SF(env) ? CC_S : 0; 302 env->eflags |= get_OF(env) ? CC_O : 0; 303} 304 305void rflags_to_lflags(CPUX86State *env) 306{ 307 env->hvf_lflags.auxbits = env->hvf_lflags.result = 0; 308 set_OF(env, env->eflags & CC_O); 309 set_SF(env, env->eflags & CC_S); 310 set_ZF(env, env->eflags & CC_Z); 311 set_AF(env, env->eflags & CC_A); 312 set_PF(env, env->eflags & CC_P); 313 set_CF(env, env->eflags & CC_C); 314}