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