LXR qemu/target/i386/hvf/x86

   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}
 315