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_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) 116 117 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_lflags.auxbits &= ~(LF_MASK_PO | LF_MASK_CF); 121 env->hvf_lflags.auxbits |= (temp_po << LF_BIT_PO) | (new_cf << LF_BIT_CF); 122 } 123 124 void 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 } 129 130 void 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 } 135 136 void 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 } 141 142 void 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 } 147 148 void 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 } 153 154 void 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 } 159 160 void 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 } 165 166 void 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 } 171 172 void 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 } 177 178 void 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 } 183 184 void 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 } 189 190 void 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 } 195 196 197 void 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 } 202 203 void 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 } 208 209 void 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 } 214 215 bool 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 } 222 223 void 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 } 229 230 bool get_OF(CPUX86State *env) 231 { 232 return ((env->hvf_lflags.auxbits + (1U << LF_BIT_PO)) >> LF_BIT_CF) & 1; 233 } 234 235 bool get_CF(CPUX86State *env) 236 { 237 return (env->hvf_lflags.auxbits >> LF_BIT_CF) & 1; 238 } 239 240 void set_OF(CPUX86State *env, bool val) 241 { 242 bool old_cf = get_CF(env); 243 SET_FLAGS_OxxxxC(env, val, old_cf); 244 } 245 246 void set_CF(CPUX86State *env, bool val) 247 { 248 bool old_of = get_OF(env); 249 SET_FLAGS_OxxxxC(env, old_of, val); 250 } 251 252 bool get_AF(CPUX86State *env) 253 { 254 return (env->hvf_lflags.auxbits >> LF_BIT_AF) & 1; 255 } 256 257 void 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 } 262 263 bool get_ZF(CPUX86State *env) 264 { 265 return !env->hvf_lflags.result; 266 } 267 268 void 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 } 282 283 bool get_SF(CPUX86State *env) 284 { 285 return ((env->hvf_lflags.result >> LF_SIGN_BIT) ^ 286 (env->hvf_lflags.auxbits >> LF_BIT_SD)) & 1; 287 } 288 289 void 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 } 294 295 void 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 } 304 305 void 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 } 315