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 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
 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_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
 125void 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
 131void 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
 137void 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
 143void 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
 149void 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
 155void 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
 161void 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
 167void 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
 173void 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
 179void 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
 185void 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
 191void 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
 198void 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
 204void 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
 210void 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
 216bool 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
 224void 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
 231bool get_OF(CPUX86State *env)
 232{
 233    return ((env->hvf_emul->lflags.auxbits + (1U << LF_BIT_PO)) >> LF_BIT_CF) & 1;
 234}
 235
 236bool get_CF(CPUX86State *env)
 237{
 238    return (env->hvf_emul->lflags.auxbits >> LF_BIT_CF) & 1;
 239}
 240
 241void set_OF(CPUX86State *env, bool val)
 242{
 243    bool old_cf = get_CF(env);
 244    SET_FLAGS_OxxxxC(env, val, old_cf);
 245}
 246
 247void set_CF(CPUX86State *env, bool val)
 248{
 249    bool old_of = get_OF(env);
 250    SET_FLAGS_OxxxxC(env, old_of, val);
 251}
 252
 253bool get_AF(CPUX86State *env)
 254{
 255    return (env->hvf_emul->lflags.auxbits >> LF_BIT_AF) & 1;
 256}
 257
 258void 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
 264bool get_ZF(CPUX86State *env)
 265{
 266    return !env->hvf_emul->lflags.result;
 267}
 268
 269void 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
 284bool 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
 290void 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
 296void 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
 306void 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