blob: 1f94e11dcf0606923d2c670d4773fdf7db9aaa69 [file] [log] [blame]
/*
* x86 condition code helpers
*
* Copyright (c) 2008 Fabrice Bellard
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#define DATA_BITS (1 << (3 + SHIFT))
#define SIGN_MASK (((target_ulong)1) << (DATA_BITS - 1))
#if DATA_BITS == 8
#define SUFFIX b
#define DATA_TYPE uint8_t
#define DATA_MASK 0xff
#elif DATA_BITS == 16
#define SUFFIX w
#define DATA_TYPE uint16_t
#define DATA_MASK 0xffff
#elif DATA_BITS == 32
#define SUFFIX l
#define DATA_TYPE uint32_t
#define DATA_MASK 0xffffffff
#elif DATA_BITS == 64
#define SUFFIX q
#define DATA_TYPE uint64_t
#define DATA_MASK 0xffffffffffffffffULL
#else
#error unhandled operand size
#endif
/* dynamic flags computation */
static int glue(compute_all_add, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
target_long src1, src2;
src1 = CC_SRC;
src2 = CC_DST - CC_SRC;
cf = (DATA_TYPE)CC_DST < (DATA_TYPE)src1;
pf = parity_table[(uint8_t)CC_DST];
af = (CC_DST ^ src1 ^ src2) & 0x10;
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
of = lshift((src1 ^ src2 ^ -1) & (src1 ^ CC_DST), 12 - DATA_BITS) & CC_O;
return cf | pf | af | zf | sf | of;
}
static int glue(compute_c_add, SUFFIX)(CPUX86State *env)
{
int cf;
target_long src1;
src1 = CC_SRC;
cf = (DATA_TYPE)CC_DST < (DATA_TYPE)src1;
return cf;
}
static int glue(compute_all_adc, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
target_long src1, src2;
src1 = CC_SRC;
src2 = CC_DST - CC_SRC - 1;
cf = (DATA_TYPE)CC_DST <= (DATA_TYPE)src1;
pf = parity_table[(uint8_t)CC_DST];
af = (CC_DST ^ src1 ^ src2) & 0x10;
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
of = lshift((src1 ^ src2 ^ -1) & (src1 ^ CC_DST), 12 - DATA_BITS) & CC_O;
return cf | pf | af | zf | sf | of;
}
static int glue(compute_c_adc, SUFFIX)(CPUX86State *env)
{
int cf;
target_long src1;
src1 = CC_SRC;
cf = (DATA_TYPE)CC_DST <= (DATA_TYPE)src1;
return cf;
}
static int glue(compute_all_sub, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
target_long src1, src2;
src1 = CC_DST + CC_SRC;
src2 = CC_SRC;
cf = (DATA_TYPE)src1 < (DATA_TYPE)src2;
pf = parity_table[(uint8_t)CC_DST];
af = (CC_DST ^ src1 ^ src2) & 0x10;
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
of = lshift((src1 ^ src2) & (src1 ^ CC_DST), 12 - DATA_BITS) & CC_O;
return cf | pf | af | zf | sf | of;
}
static int glue(compute_c_sub, SUFFIX)(CPUX86State *env)
{
int cf;
target_long src1, src2;
src1 = CC_DST + CC_SRC;
src2 = CC_SRC;
cf = (DATA_TYPE)src1 < (DATA_TYPE)src2;
return cf;
}
static int glue(compute_all_sbb, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
target_long src1, src2;
src1 = CC_DST + CC_SRC + 1;
src2 = CC_SRC;
cf = (DATA_TYPE)src1 <= (DATA_TYPE)src2;
pf = parity_table[(uint8_t)CC_DST];
af = (CC_DST ^ src1 ^ src2) & 0x10;
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
of = lshift((src1 ^ src2) & (src1 ^ CC_DST), 12 - DATA_BITS) & CC_O;
return cf | pf | af | zf | sf | of;
}
static int glue(compute_c_sbb, SUFFIX)(CPUX86State *env)
{
int cf;
target_long src1, src2;
src1 = CC_DST + CC_SRC + 1;
src2 = CC_SRC;
cf = (DATA_TYPE)src1 <= (DATA_TYPE)src2;
return cf;
}
static int glue(compute_all_logic, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
cf = 0;
pf = parity_table[(uint8_t)CC_DST];
af = 0;
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
of = 0;
return cf | pf | af | zf | sf | of;
}
static int glue(compute_c_logic, SUFFIX)(void)
{
return 0;
}
static int glue(compute_all_inc, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
target_long src1, src2;
src1 = CC_DST - 1;
src2 = 1;
cf = CC_SRC;
pf = parity_table[(uint8_t)CC_DST];
af = (CC_DST ^ src1 ^ src2) & 0x10;
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
of = ((CC_DST & DATA_MASK) == SIGN_MASK) << 11;
return cf | pf | af | zf | sf | of;
}
#if DATA_BITS == 32
static int glue(compute_c_inc, SUFFIX)(CPUX86State *env)
{
return CC_SRC;
}
#endif
static int glue(compute_all_dec, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
target_long src1, src2;
src1 = CC_DST + 1;
src2 = 1;
cf = CC_SRC;
pf = parity_table[(uint8_t)CC_DST];
af = (CC_DST ^ src1 ^ src2) & 0x10;
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
of = ((CC_DST & DATA_MASK) == ((target_ulong)SIGN_MASK - 1)) << 11;
return cf | pf | af | zf | sf | of;
}
static int glue(compute_all_shl, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
cf = (CC_SRC >> (DATA_BITS - 1)) & CC_C;
pf = parity_table[(uint8_t)CC_DST];
af = 0; /* undefined */
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
/* of is defined if shift count == 1 */
of = lshift(CC_SRC ^ CC_DST, 12 - DATA_BITS) & CC_O;
return cf | pf | af | zf | sf | of;
}
static int glue(compute_c_shl, SUFFIX)(CPUX86State *env)
{
return (CC_SRC >> (DATA_BITS - 1)) & CC_C;
}
#if DATA_BITS == 32
static int glue(compute_c_sar, SUFFIX)(CPUX86State *env)
{
return CC_SRC & 1;
}
#endif
static int glue(compute_all_sar, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
cf = CC_SRC & 1;
pf = parity_table[(uint8_t)CC_DST];
af = 0; /* undefined */
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
/* of is defined if shift count == 1 */
of = lshift(CC_SRC ^ CC_DST, 12 - DATA_BITS) & CC_O;
return cf | pf | af | zf | sf | of;
}
#if DATA_BITS == 32
static int glue(compute_c_mul, SUFFIX)(CPUX86State *env)
{
int cf;
cf = (CC_SRC != 0);
return cf;
}
#endif
/* NOTE: we compute the flags like the P4. On olders CPUs, only OF and
CF are modified and it is slower to do that. */
static int glue(compute_all_mul, SUFFIX)(CPUX86State *env)
{
int cf, pf, af, zf, sf, of;
cf = (CC_SRC != 0);
pf = parity_table[(uint8_t)CC_DST];
af = 0; /* undefined */
zf = ((DATA_TYPE)CC_DST == 0) << 6;
sf = lshift(CC_DST, 8 - DATA_BITS) & 0x80;
of = cf << 11;
return cf | pf | af | zf | sf | of;
}
#undef DATA_BITS
#undef SIGN_MASK
#undef DATA_TYPE
#undef DATA_MASK
#undef SUFFIX