/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001-2012 The Bochs Project
// Copyright (C) 2017 Google Inc.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA
/////////////////////////////////////////////////////////////////////////
/*
* flags functions
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "panic.h"
#include "cpu.h"
#include "x86_flags.h"
#include "x86.h"
/* this is basically bocsh code */
#define LF_SIGN_BIT 31
#define LF_BIT_SD (0) /* lazy Sign Flag Delta */
#define LF_BIT_AF (3) /* lazy Adjust flag */
#define LF_BIT_PDB (8) /* lazy Parity Delta Byte (8 bits) */
#define LF_BIT_CF (31) /* lazy Carry Flag */
#define LF_BIT_PO (30) /* lazy Partial Overflow = CF ^ OF */
#define LF_MASK_SD (0x01 << LF_BIT_SD)
#define LF_MASK_AF (0x01 << LF_BIT_AF)
#define LF_MASK_PDB (0xFF << LF_BIT_PDB)
#define LF_MASK_CF (0x01 << LF_BIT_CF)
#define LF_MASK_PO (0x01 << LF_BIT_PO)
#define ADD_COUT_VEC(op1, op2, result) \
(((op1) & (op2)) | (((op1) | (op2)) & (~(result))))
#define SUB_COUT_VEC(op1, op2, result) \
(((~(op1)) & (op2)) | (((~(op1)) ^ (op2)) & (result)))
#define GET_ADD_OVERFLOW(op1, op2, result, mask) \
((((op1) ^ (result)) & ((op2) ^ (result))) & (mask))
/* ******************* */
/* OSZAPC */
/* ******************* */
/* size, carries, result */
#define SET_FLAGS_OSZAPC_SIZE(size, lf_carries, lf_result) { \
target_ulong temp = ((lf_carries) & (LF_MASK_AF)) | \
(((lf_carries) >> (size - 2)) << LF_BIT_PO); \
env->hvf_lflags.result = (target_ulong)(int##size##_t)(lf_result); \
if ((size) == 32) { \
temp = ((lf_carries) & ~(LF_MASK_PDB | LF_MASK_SD)); \
} else if ((size) == 16) { \
temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 16); \
} else if ((size) == 8) { \
temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 24); \
} else { \
VM_PANIC("unimplemented"); \
} \
env->hvf_lflags.auxbits = (target_ulong)(uint32_t)temp; \
}
/* carries, result */
#define SET_FLAGS_OSZAPC_8(carries, result) \
SET_FLAGS_OSZAPC_SIZE(8, carries, result)
#define SET_FLAGS_OSZAPC_16(carries, result) \
SET_FLAGS_OSZAPC_SIZE(16, carries, result)
#define SET_FLAGS_OSZAPC_32(carries, result) \
SET_FLAGS_OSZAPC_SIZE(32, carries, result)
/* ******************* */
/* OSZAP */
/* ******************* */
/* size, carries, result */
#define SET_FLAGS_OSZAP_SIZE(size, lf_carries, lf_result) { \
target_ulong temp = ((lf_carries) & (LF_MASK_AF)) | \
(((lf_carries) >> (size - 2)) << LF_BIT_PO); \
if ((size) == 32) { \
temp = ((lf_carries) & ~(LF_MASK_PDB | LF_MASK_SD)); \
} else if ((size) == 16) { \
temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 16); \
} else if ((size) == 8) { \
temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 24); \
} else { \
VM_PANIC("unimplemented"); \
} \
env->hvf_lflags.result = (target_ulong)(int##size##_t)(lf_result); \
target_ulong delta_c = (env->hvf_lflags.auxbits ^ temp) & LF_MASK_CF; \
delta_c ^= (delta_c >> 1); \
env->hvf_lflags.auxbits = (target_ulong)(uint32_t)(temp ^ delta_c); \
}
/* carries, result */
#define SET_FLAGS_OSZAP_8(carries, result) \
SET_FLAGS_OSZAP_SIZE(8, carries, result)
#define SET_FLAGS_OSZAP_16(carries, result) \
SET_FLAGS_OSZAP_SIZE(16, carries, result)
#define SET_FLAGS_OSZAP_32(carries, result) \
SET_FLAGS_OSZAP_SIZE(32, carries, result)
void SET_FLAGS_OxxxxC(CPUX86State *env, uint32_t new_of, uint32_t new_cf)
{
uint32_t temp_po = new_of ^ new_cf;
env->hvf_lflags.auxbits &= ~(LF_MASK_PO | LF_MASK_CF);
env->hvf_lflags.auxbits |= (temp_po << LF_BIT_PO) | (new_cf << LF_BIT_CF);
}
void SET_FLAGS_OSZAPC_SUB32(CPUX86State *env, uint32_t v1, uint32_t v2,
uint32_t diff)
{
SET_FLAGS_OSZAPC_32(SUB_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAPC_SUB16(CPUX86State *env, uint16_t v1, uint16_t v2,
uint16_t diff)
{
SET_FLAGS_OSZAPC_16(SUB_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAPC_SUB8(CPUX86State *env, uint8_t v1, uint8_t v2,
uint8_t diff)
{
SET_FLAGS_OSZAPC_8(SUB_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAPC_ADD32(CPUX86State *env, uint32_t v1, uint32_t v2,
uint32_t diff)
{
SET_FLAGS_OSZAPC_32(ADD_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAPC_ADD16(CPUX86State *env, uint16_t v1, uint16_t v2,
uint16_t diff)
{
SET_FLAGS_OSZAPC_16(ADD_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAPC_ADD8(CPUX86State *env, uint8_t v1, uint8_t v2,
uint8_t diff)
{
SET_FLAGS_OSZAPC_8(ADD_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAP_SUB32(CPUX86State *env, uint32_t v1, uint32_t v2,
uint32_t diff)
{
SET_FLAGS_OSZAP_32(SUB_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAP_SUB16(CPUX86State *env, uint16_t v1, uint16_t v2,
uint16_t diff)
{
SET_FLAGS_OSZAP_16(SUB_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAP_SUB8(CPUX86State *env, uint8_t v1, uint8_t v2,
uint8_t diff)
{
SET_FLAGS_OSZAP_8(SUB_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAP_ADD32(CPUX86State *env, uint32_t v1, uint32_t v2,
uint32_t diff)
{
SET_FLAGS_OSZAP_32(ADD_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAP_ADD16(CPUX86State *env, uint16_t v1, uint16_t v2,
uint16_t diff)
{
SET_FLAGS_OSZAP_16(ADD_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAP_ADD8(CPUX86State *env, uint8_t v1, uint8_t v2,
uint8_t diff)
{
SET_FLAGS_OSZAP_8(ADD_COUT_VEC(v1, v2, diff), diff);
}
void SET_FLAGS_OSZAPC_LOGIC32(CPUX86State *env, uint32_t v1, uint32_t v2,
uint32_t diff)
{
SET_FLAGS_OSZAPC_32(0, diff);
}
void SET_FLAGS_OSZAPC_LOGIC16(CPUX86State *env, uint16_t v1, uint16_t v2,
uint16_t diff)
{
SET_FLAGS_OSZAPC_16(0, diff);
}
void SET_FLAGS_OSZAPC_LOGIC8(CPUX86State *env, uint8_t v1, uint8_t v2,
uint8_t diff)
{
SET_FLAGS_OSZAPC_8(0, diff);
}
bool get_PF(CPUX86State *env)
{
uint32_t temp = (255 & env->hvf_lflags.result);
temp = temp ^ (255 & (env->hvf_lflags.auxbits >> LF_BIT_PDB));
temp = (temp ^ (temp >> 4)) & 0x0F;
return (0x9669U >> temp) & 1;
}
void set_PF(CPUX86State *env, bool val)
{
uint32_t temp = (255 & env->hvf_lflags.result) ^ (!val);
env->hvf_lflags.auxbits &= ~(LF_MASK_PDB);
env->hvf_lflags.auxbits |= (temp << LF_BIT_PDB);
}
bool get_OF(CPUX86State *env)
{
return ((env->hvf_lflags.auxbits + (1U << LF_BIT_PO)) >> LF_BIT_CF) & 1;
}
bool get_CF(CPUX86State *env)
{
return (env->hvf_lflags.auxbits >> LF_BIT_CF) & 1;
}
void set_OF(CPUX86State *env, bool val)
{
bool old_cf = get_CF(env);
SET_FLAGS_OxxxxC(env, val, old_cf);
}
void set_CF(CPUX86State *env, bool val)
{
bool old_of = get_OF(env);
SET_FLAGS_OxxxxC(env, old_of, val);
}
bool get_AF(CPUX86State *env)
{
return (env->hvf_lflags.auxbits >> LF_BIT_AF) & 1;
}
void set_AF(CPUX86State *env, bool val)
{
env->hvf_lflags.auxbits &= ~(LF_MASK_AF);
env->hvf_lflags.auxbits |= val << LF_BIT_AF;
}
bool get_ZF(CPUX86State *env)
{
return !env->hvf_lflags.result;
}
void set_ZF(CPUX86State *env, bool val)
{
if (val) {
env->hvf_lflags.auxbits ^=
(((env->hvf_lflags.result >> LF_SIGN_BIT) & 1) << LF_BIT_SD);
/* merge the parity bits into the Parity Delta Byte */
uint32_t temp_pdb = (255 & env->hvf_lflags.result);
env->hvf_lflags.auxbits ^= (temp_pdb << LF_BIT_PDB);
/* now zero the .result value */
env->hvf_lflags.result = 0;
} else {
env->hvf_lflags.result |= (1 << 8);
}
}
bool get_SF(CPUX86State *env)
{
return ((env->hvf_lflags.result >> LF_SIGN_BIT) ^
(env->hvf_lflags.auxbits >> LF_BIT_SD)) & 1;
}
void set_SF(CPUX86State *env, bool val)
{
bool temp_sf = get_SF(env);
env->hvf_lflags.auxbits ^= (temp_sf ^ val) << LF_BIT_SD;
}
void lflags_to_rflags(CPUX86State *env)
{
env->eflags |= get_CF(env) ? CC_C : 0;
env->eflags |= get_PF(env) ? CC_P : 0;
env->eflags |= get_AF(env) ? CC_A : 0;
env->eflags |= get_ZF(env) ? CC_Z : 0;
env->eflags |= get_SF(env) ? CC_S : 0;
env->eflags |= get_OF(env) ? CC_O : 0;
}
void rflags_to_lflags(CPUX86State *env)
{
env->hvf_lflags.auxbits = env->hvf_lflags.result = 0;
set_OF(env, env->eflags & CC_O);
set_SF(env, env->eflags & CC_S);
set_ZF(env, env->eflags & CC_Z);
set_AF(env, env->eflags & CC_A);
set_PF(env, env->eflags & CC_P);
set_CF(env, env->eflags & CC_C);
}
