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 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_emul->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_emul->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_emul->lflags.result = (target_ulong)(int##size##_t)(lf_result); \ 104 target_ulong delta_c = (env->hvf_emul->lflags.auxbits ^ temp) & LF_MASK_CF; \ 105 delta_c ^= (delta_c >> 1); \ 106 env->hvf_emul->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) 116 117 void 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_emul->lflags.auxbits &= ~(LF_MASK_PO | LF_MASK_CF); 121 env->hvf_emul->lflags.auxbits |= (temp_po << LF_BIT_PO) | 122 (new_cf << LF_BIT_CF); 123 } 124 125 void SET_FLAGS_OSZAPC_SUB32(CPUX86State *env, uint32_t v1, uint32_t v2, 126 uint32_t diff) 127 { 128 SET_FLAGS_OSZAPC_32(SUB_COUT_VEC(v1, v2, diff), diff); 129 } 130 131 void SET_FLAGS_OSZAPC_SUB16(CPUX86State *env, uint16_t v1, uint16_t v2, 132 uint16_t diff) 133 { 134 SET_FLAGS_OSZAPC_16(SUB_COUT_VEC(v1, v2, diff), diff); 135 } 136 137 void SET_FLAGS_OSZAPC_SUB8(CPUX86State *env, uint8_t v1, uint8_t v2, 138 uint8_t diff) 139 { 140 SET_FLAGS_OSZAPC_8(SUB_COUT_VEC(v1, v2, diff), diff); 141 } 142 143 void SET_FLAGS_OSZAPC_ADD32(CPUX86State *env, uint32_t v1, uint32_t v2, 144 uint32_t diff) 145 { 146 SET_FLAGS_OSZAPC_32(ADD_COUT_VEC(v1, v2, diff), diff); 147 } 148 149 void SET_FLAGS_OSZAPC_ADD16(CPUX86State *env, uint16_t v1, uint16_t v2, 150 uint16_t diff) 151 { 152 SET_FLAGS_OSZAPC_16(ADD_COUT_VEC(v1, v2, diff), diff); 153 } 154 155 void SET_FLAGS_OSZAPC_ADD8(CPUX86State *env, uint8_t v1, uint8_t v2, 156 uint8_t diff) 157 { 158 SET_FLAGS_OSZAPC_8(ADD_COUT_VEC(v1, v2, diff), diff); 159 } 160 161 void SET_FLAGS_OSZAP_SUB32(CPUX86State *env, uint32_t v1, uint32_t v2, 162 uint32_t diff) 163 { 164 SET_FLAGS_OSZAP_32(SUB_COUT_VEC(v1, v2, diff), diff); 165 } 166 167 void SET_FLAGS_OSZAP_SUB16(CPUX86State *env, uint16_t v1, uint16_t v2, 168 uint16_t diff) 169 { 170 SET_FLAGS_OSZAP_16(SUB_COUT_VEC(v1, v2, diff), diff); 171 } 172 173 void SET_FLAGS_OSZAP_SUB8(CPUX86State *env, uint8_t v1, uint8_t v2, 174 uint8_t diff) 175 { 176 SET_FLAGS_OSZAP_8(SUB_COUT_VEC(v1, v2, diff), diff); 177 } 178 179 void SET_FLAGS_OSZAP_ADD32(CPUX86State *env, uint32_t v1, uint32_t v2, 180 uint32_t diff) 181 { 182 SET_FLAGS_OSZAP_32(ADD_COUT_VEC(v1, v2, diff), diff); 183 } 184 185 void SET_FLAGS_OSZAP_ADD16(CPUX86State *env, uint16_t v1, uint16_t v2, 186 uint16_t diff) 187 { 188 SET_FLAGS_OSZAP_16(ADD_COUT_VEC(v1, v2, diff), diff); 189 } 190 191 void SET_FLAGS_OSZAP_ADD8(CPUX86State *env, uint8_t v1, uint8_t v2, 192 uint8_t diff) 193 { 194 SET_FLAGS_OSZAP_8(ADD_COUT_VEC(v1, v2, diff), diff); 195 } 196 197 198 void SET_FLAGS_OSZAPC_LOGIC32(CPUX86State *env, uint32_t v1, uint32_t v2, 199 uint32_t diff) 200 { 201 SET_FLAGS_OSZAPC_32(0, diff); 202 } 203 204 void SET_FLAGS_OSZAPC_LOGIC16(CPUX86State *env, uint16_t v1, uint16_t v2, 205 uint16_t diff) 206 { 207 SET_FLAGS_OSZAPC_16(0, diff); 208 } 209 210 void SET_FLAGS_OSZAPC_LOGIC8(CPUX86State *env, uint8_t v1, uint8_t v2, 211 uint8_t diff) 212 { 213 SET_FLAGS_OSZAPC_8(0, diff); 214 } 215 216 bool get_PF(CPUX86State *env) 217 { 218 uint32_t temp = (255 & env->hvf_emul->lflags.result); 219 temp = temp ^ (255 & (env->hvf_emul->lflags.auxbits >> LF_BIT_PDB)); 220 temp = (temp ^ (temp >> 4)) & 0x0F; 221 return (0x9669U >> temp) & 1; 222 } 223 224 void set_PF(CPUX86State *env, bool val) 225 { 226 uint32_t temp = (255 & env->hvf_emul->lflags.result) ^ (!val); 227 env->hvf_emul->lflags.auxbits &= ~(LF_MASK_PDB); 228 env->hvf_emul->lflags.auxbits |= (temp << LF_BIT_PDB); 229 } 230 231 bool get_OF(CPUX86State *env) 232 { 233 return ((env->hvf_emul->lflags.auxbits + (1U << LF_BIT_PO)) >> LF_BIT_CF) & 1; 234 } 235 236 bool get_CF(CPUX86State *env) 237 { 238 return (env->hvf_emul->lflags.auxbits >> LF_BIT_CF) & 1; 239 } 240 241 void set_OF(CPUX86State *env, bool val) 242 { 243 bool old_cf = get_CF(env); 244 SET_FLAGS_OxxxxC(env, val, old_cf); 245 } 246 247 void set_CF(CPUX86State *env, bool val) 248 { 249 bool old_of = get_OF(env); 250 SET_FLAGS_OxxxxC(env, old_of, val); 251 } 252 253 bool get_AF(CPUX86State *env) 254 { 255 return (env->hvf_emul->lflags.auxbits >> LF_BIT_AF) & 1; 256 } 257 258 void set_AF(CPUX86State *env, bool val) 259 { 260 env->hvf_emul->lflags.auxbits &= ~(LF_MASK_AF); 261 env->hvf_emul->lflags.auxbits |= val << LF_BIT_AF; 262 } 263 264 bool get_ZF(CPUX86State *env) 265 { 266 return !env->hvf_emul->lflags.result; 267 } 268 269 void set_ZF(CPUX86State *env, bool val) 270 { 271 if (val) { 272 env->hvf_emul->lflags.auxbits ^= 273 (((env->hvf_emul->lflags.result >> LF_SIGN_BIT) & 1) << LF_BIT_SD); 274 /* merge the parity bits into the Parity Delta Byte */ 275 uint32_t temp_pdb = (255 & env->hvf_emul->lflags.result); 276 env->hvf_emul->lflags.auxbits ^= (temp_pdb << LF_BIT_PDB); 277 /* now zero the .result value */ 278 env->hvf_emul->lflags.result = 0; 279 } else { 280 env->hvf_emul->lflags.result |= (1 << 8); 281 } 282 } 283 284 bool get_SF(CPUX86State *env) 285 { 286 return ((env->hvf_emul->lflags.result >> LF_SIGN_BIT) ^ 287 (env->hvf_emul->lflags.auxbits >> LF_BIT_SD)) & 1; 288 } 289 290 void set_SF(CPUX86State *env, bool val) 291 { 292 bool temp_sf = get_SF(env); 293 env->hvf_emul->lflags.auxbits ^= (temp_sf ^ val) << LF_BIT_SD; 294 } 295 296 void lflags_to_rflags(CPUX86State *env) 297 { 298 env->hvf_emul->rflags.cf = get_CF(env); 299 env->hvf_emul->rflags.pf = get_PF(env); 300 env->hvf_emul->rflags.af = get_AF(env); 301 env->hvf_emul->rflags.zf = get_ZF(env); 302 env->hvf_emul->rflags.sf = get_SF(env); 303 env->hvf_emul->rflags.of = get_OF(env); 304 } 305 306 void rflags_to_lflags(CPUX86State *env) 307 { 308 env->hvf_emul->lflags.auxbits = env->hvf_emul->lflags.result = 0; 309 set_OF(env, env->hvf_emul->rflags.of); 310 set_SF(env, env->hvf_emul->rflags.sf); 311 set_ZF(env, env->hvf_emul->rflags.zf); 312 set_AF(env, env->hvf_emul->rflags.af); 313 set_PF(env, env->hvf_emul->rflags.pf); 314 set_CF(env, env->hvf_emul->rflags.cf); 315 } 316