x86_flags.c (9728B)
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 "panic.h" 27 #include "cpu.h" 28 #include "x86_flags.h" 29 #include "x86.h" 30 31 32 /* this is basically bocsh code */ 33 34 #define LF_SIGN_BIT 31 35 36 #define LF_BIT_SD (0) /* lazy Sign Flag Delta */ 37 #define LF_BIT_AF (3) /* lazy Adjust flag */ 38 #define LF_BIT_PDB (8) /* lazy Parity Delta Byte (8 bits) */ 39 #define LF_BIT_CF (31) /* lazy Carry Flag */ 40 #define LF_BIT_PO (30) /* lazy Partial Overflow = CF ^ OF */ 41 42 #define LF_MASK_SD (0x01 << LF_BIT_SD) 43 #define LF_MASK_AF (0x01 << LF_BIT_AF) 44 #define LF_MASK_PDB (0xFF << LF_BIT_PDB) 45 #define LF_MASK_CF (0x01 << LF_BIT_CF) 46 #define LF_MASK_PO (0x01 << LF_BIT_PO) 47 48 #define ADD_COUT_VEC(op1, op2, result) \ 49 (((op1) & (op2)) | (((op1) | (op2)) & (~(result)))) 50 51 #define SUB_COUT_VEC(op1, op2, result) \ 52 (((~(op1)) & (op2)) | (((~(op1)) ^ (op2)) & (result))) 53 54 #define GET_ADD_OVERFLOW(op1, op2, result, mask) \ 55 ((((op1) ^ (result)) & ((op2) ^ (result))) & (mask)) 56 57 /* ******************* */ 58 /* OSZAPC */ 59 /* ******************* */ 60 61 /* size, carries, result */ 62 #define SET_FLAGS_OSZAPC_SIZE(size, lf_carries, lf_result) { \ 63 target_ulong temp = ((lf_carries) & (LF_MASK_AF)) | \ 64 (((lf_carries) >> (size - 2)) << LF_BIT_PO); \ 65 env->hvf_lflags.result = (target_ulong)(int##size##_t)(lf_result); \ 66 if ((size) == 32) { \ 67 temp = ((lf_carries) & ~(LF_MASK_PDB | LF_MASK_SD)); \ 68 } else if ((size) == 16) { \ 69 temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 16); \ 70 } else if ((size) == 8) { \ 71 temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 24); \ 72 } else { \ 73 VM_PANIC("unimplemented"); \ 74 } \ 75 env->hvf_lflags.auxbits = (target_ulong)(uint32_t)temp; \ 76 } 77 78 /* carries, result */ 79 #define SET_FLAGS_OSZAPC_8(carries, result) \ 80 SET_FLAGS_OSZAPC_SIZE(8, carries, result) 81 #define SET_FLAGS_OSZAPC_16(carries, result) \ 82 SET_FLAGS_OSZAPC_SIZE(16, carries, result) 83 #define SET_FLAGS_OSZAPC_32(carries, result) \ 84 SET_FLAGS_OSZAPC_SIZE(32, carries, result) 85 86 /* ******************* */ 87 /* OSZAP */ 88 /* ******************* */ 89 /* size, carries, result */ 90 #define SET_FLAGS_OSZAP_SIZE(size, lf_carries, lf_result) { \ 91 target_ulong temp = ((lf_carries) & (LF_MASK_AF)) | \ 92 (((lf_carries) >> (size - 2)) << LF_BIT_PO); \ 93 if ((size) == 32) { \ 94 temp = ((lf_carries) & ~(LF_MASK_PDB | LF_MASK_SD)); \ 95 } else if ((size) == 16) { \ 96 temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 16); \ 97 } else if ((size) == 8) { \ 98 temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 24); \ 99 } else { \ 100 VM_PANIC("unimplemented"); \ 101 } \ 102 env->hvf_lflags.result = (target_ulong)(int##size##_t)(lf_result); \ 103 target_ulong delta_c = (env->hvf_lflags.auxbits ^ temp) & LF_MASK_CF; \ 104 delta_c ^= (delta_c >> 1); \ 105 env->hvf_lflags.auxbits = (target_ulong)(uint32_t)(temp ^ delta_c); \ 106 } 107 108 /* carries, result */ 109 #define SET_FLAGS_OSZAP_8(carries, result) \ 110 SET_FLAGS_OSZAP_SIZE(8, carries, result) 111 #define SET_FLAGS_OSZAP_16(carries, result) \ 112 SET_FLAGS_OSZAP_SIZE(16, carries, result) 113 #define SET_FLAGS_OSZAP_32(carries, result) \ 114 SET_FLAGS_OSZAP_SIZE(32, carries, result) 115 116 void SET_FLAGS_OxxxxC(CPUX86State *env, uint32_t new_of, uint32_t new_cf) 117 { 118 uint32_t temp_po = new_of ^ new_cf; 119 env->hvf_lflags.auxbits &= ~(LF_MASK_PO | LF_MASK_CF); 120 env->hvf_lflags.auxbits |= (temp_po << LF_BIT_PO) | (new_cf << LF_BIT_CF); 121 } 122 123 void SET_FLAGS_OSZAPC_SUB32(CPUX86State *env, uint32_t v1, uint32_t v2, 124 uint32_t diff) 125 { 126 SET_FLAGS_OSZAPC_32(SUB_COUT_VEC(v1, v2, diff), diff); 127 } 128 129 void SET_FLAGS_OSZAPC_SUB16(CPUX86State *env, uint16_t v1, uint16_t v2, 130 uint16_t diff) 131 { 132 SET_FLAGS_OSZAPC_16(SUB_COUT_VEC(v1, v2, diff), diff); 133 } 134 135 void SET_FLAGS_OSZAPC_SUB8(CPUX86State *env, uint8_t v1, uint8_t v2, 136 uint8_t diff) 137 { 138 SET_FLAGS_OSZAPC_8(SUB_COUT_VEC(v1, v2, diff), diff); 139 } 140 141 void SET_FLAGS_OSZAPC_ADD32(CPUX86State *env, uint32_t v1, uint32_t v2, 142 uint32_t diff) 143 { 144 SET_FLAGS_OSZAPC_32(ADD_COUT_VEC(v1, v2, diff), diff); 145 } 146 147 void SET_FLAGS_OSZAPC_ADD16(CPUX86State *env, uint16_t v1, uint16_t v2, 148 uint16_t diff) 149 { 150 SET_FLAGS_OSZAPC_16(ADD_COUT_VEC(v1, v2, diff), diff); 151 } 152 153 void SET_FLAGS_OSZAPC_ADD8(CPUX86State *env, uint8_t v1, uint8_t v2, 154 uint8_t diff) 155 { 156 SET_FLAGS_OSZAPC_8(ADD_COUT_VEC(v1, v2, diff), diff); 157 } 158 159 void SET_FLAGS_OSZAP_SUB32(CPUX86State *env, uint32_t v1, uint32_t v2, 160 uint32_t diff) 161 { 162 SET_FLAGS_OSZAP_32(SUB_COUT_VEC(v1, v2, diff), diff); 163 } 164 165 void SET_FLAGS_OSZAP_SUB16(CPUX86State *env, uint16_t v1, uint16_t v2, 166 uint16_t diff) 167 { 168 SET_FLAGS_OSZAP_16(SUB_COUT_VEC(v1, v2, diff), diff); 169 } 170 171 void SET_FLAGS_OSZAP_SUB8(CPUX86State *env, uint8_t v1, uint8_t v2, 172 uint8_t diff) 173 { 174 SET_FLAGS_OSZAP_8(SUB_COUT_VEC(v1, v2, diff), diff); 175 } 176 177 void SET_FLAGS_OSZAP_ADD32(CPUX86State *env, uint32_t v1, uint32_t v2, 178 uint32_t diff) 179 { 180 SET_FLAGS_OSZAP_32(ADD_COUT_VEC(v1, v2, diff), diff); 181 } 182 183 void SET_FLAGS_OSZAP_ADD16(CPUX86State *env, uint16_t v1, uint16_t v2, 184 uint16_t diff) 185 { 186 SET_FLAGS_OSZAP_16(ADD_COUT_VEC(v1, v2, diff), diff); 187 } 188 189 void SET_FLAGS_OSZAP_ADD8(CPUX86State *env, uint8_t v1, uint8_t v2, 190 uint8_t diff) 191 { 192 SET_FLAGS_OSZAP_8(ADD_COUT_VEC(v1, v2, diff), diff); 193 } 194 195 196 void SET_FLAGS_OSZAPC_LOGIC32(CPUX86State *env, uint32_t v1, uint32_t v2, 197 uint32_t diff) 198 { 199 SET_FLAGS_OSZAPC_32(0, diff); 200 } 201 202 void SET_FLAGS_OSZAPC_LOGIC16(CPUX86State *env, uint16_t v1, uint16_t v2, 203 uint16_t diff) 204 { 205 SET_FLAGS_OSZAPC_16(0, diff); 206 } 207 208 void SET_FLAGS_OSZAPC_LOGIC8(CPUX86State *env, uint8_t v1, uint8_t v2, 209 uint8_t diff) 210 { 211 SET_FLAGS_OSZAPC_8(0, diff); 212 } 213 214 bool get_PF(CPUX86State *env) 215 { 216 uint32_t temp = (255 & env->hvf_lflags.result); 217 temp = temp ^ (255 & (env->hvf_lflags.auxbits >> LF_BIT_PDB)); 218 temp = (temp ^ (temp >> 4)) & 0x0F; 219 return (0x9669U >> temp) & 1; 220 } 221 222 void set_PF(CPUX86State *env, bool val) 223 { 224 uint32_t temp = (255 & env->hvf_lflags.result) ^ (!val); 225 env->hvf_lflags.auxbits &= ~(LF_MASK_PDB); 226 env->hvf_lflags.auxbits |= (temp << LF_BIT_PDB); 227 } 228 229 bool get_OF(CPUX86State *env) 230 { 231 return ((env->hvf_lflags.auxbits + (1U << LF_BIT_PO)) >> LF_BIT_CF) & 1; 232 } 233 234 bool get_CF(CPUX86State *env) 235 { 236 return (env->hvf_lflags.auxbits >> LF_BIT_CF) & 1; 237 } 238 239 void set_OF(CPUX86State *env, bool val) 240 { 241 bool old_cf = get_CF(env); 242 SET_FLAGS_OxxxxC(env, val, old_cf); 243 } 244 245 void set_CF(CPUX86State *env, bool val) 246 { 247 bool old_of = get_OF(env); 248 SET_FLAGS_OxxxxC(env, old_of, val); 249 } 250 251 bool get_AF(CPUX86State *env) 252 { 253 return (env->hvf_lflags.auxbits >> LF_BIT_AF) & 1; 254 } 255 256 void set_AF(CPUX86State *env, bool val) 257 { 258 env->hvf_lflags.auxbits &= ~(LF_MASK_AF); 259 env->hvf_lflags.auxbits |= val << LF_BIT_AF; 260 } 261 262 bool get_ZF(CPUX86State *env) 263 { 264 return !env->hvf_lflags.result; 265 } 266 267 void set_ZF(CPUX86State *env, bool val) 268 { 269 if (val) { 270 env->hvf_lflags.auxbits ^= 271 (((env->hvf_lflags.result >> LF_SIGN_BIT) & 1) << LF_BIT_SD); 272 /* merge the parity bits into the Parity Delta Byte */ 273 uint32_t temp_pdb = (255 & env->hvf_lflags.result); 274 env->hvf_lflags.auxbits ^= (temp_pdb << LF_BIT_PDB); 275 /* now zero the .result value */ 276 env->hvf_lflags.result = 0; 277 } else { 278 env->hvf_lflags.result |= (1 << 8); 279 } 280 } 281 282 bool get_SF(CPUX86State *env) 283 { 284 return ((env->hvf_lflags.result >> LF_SIGN_BIT) ^ 285 (env->hvf_lflags.auxbits >> LF_BIT_SD)) & 1; 286 } 287 288 void set_SF(CPUX86State *env, bool val) 289 { 290 bool temp_sf = get_SF(env); 291 env->hvf_lflags.auxbits ^= (temp_sf ^ val) << LF_BIT_SD; 292 } 293 294 void lflags_to_rflags(CPUX86State *env) 295 { 296 env->eflags |= get_CF(env) ? CC_C : 0; 297 env->eflags |= get_PF(env) ? CC_P : 0; 298 env->eflags |= get_AF(env) ? CC_A : 0; 299 env->eflags |= get_ZF(env) ? CC_Z : 0; 300 env->eflags |= get_SF(env) ? CC_S : 0; 301 env->eflags |= get_OF(env) ? CC_O : 0; 302 } 303 304 void rflags_to_lflags(CPUX86State *env) 305 { 306 env->hvf_lflags.auxbits = env->hvf_lflags.result = 0; 307 set_OF(env, env->eflags & CC_O); 308 set_SF(env, env->eflags & CC_S); 309 set_ZF(env, env->eflags & CC_Z); 310 set_AF(env, env->eflags & CC_A); 311 set_PF(env, env->eflags & CC_P); 312 set_CF(env, env->eflags & CC_C); 313 }