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target-i386: Make helper_cc_compute_{all,c} const 

Pass the data in explicitly, rather than indirectly via env.
This avoids all sorts of unnecessary register spillage.

Signed-off-by: Richard Henderson <rth@twiddle.net>
master
Richard Henderson 2013-01-23 16:10:49 -08:00
parent 8601c0b6c5
commit db9f259772
3 changed files with 33 additions and 14 deletions
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12
target-i386/cc_helper.c
View File

@ -75,10 +75,8 @@ const uint8_t parity_table[256] = {
#endif
uint32_t helper_cc_compute_all(CPUX86State *env, int op)
target_ulong helper_cc_compute_all(target_ulong dst, target_ulong src1, int op)
{
target_ulong dst = CC_DST, src1 = CC_SRC;
switch (op) {
default: /* should never happen */
return 0;
@ -183,13 +181,11 @@ uint32_t helper_cc_compute_all(CPUX86State *env, int op)
uint32_t cpu_cc_compute_all(CPUX86State *env, int op)
{
return helper_cc_compute_all(env, op);
return helper_cc_compute_all(CC_DST, CC_SRC, op);
}
uint32_t helper_cc_compute_c(CPUX86State *env, int op)
target_ulong helper_cc_compute_c(target_ulong dst, target_ulong src1, int op)
{
target_ulong dst = CC_DST, src1 = CC_SRC;
switch (op) {
default: /* should never happen */
case CC_OP_LOGICB:
@ -281,7 +277,7 @@ target_ulong helper_read_eflags(CPUX86State *env)
{
uint32_t eflags;
eflags = helper_cc_compute_all(env, CC_OP);
eflags = cpu_cc_compute_all(env, CC_OP);
eflags |= (DF & DF_MASK);
eflags |= env->eflags & ~(VM_MASK | RF_MASK);
return eflags;

4
target-i386/helper.h
View File

@ -1,7 +1,7 @@
#include "exec/def-helper.h"
DEF_HELPER_FLAGS_2(cc_compute_all, TCG_CALL_NO_SE, i32, env, int)
DEF_HELPER_FLAGS_2(cc_compute_c, TCG_CALL_NO_SE, i32, env, int)
DEF_HELPER_FLAGS_3(cc_compute_all, TCG_CALL_NO_RWG_SE, tl, tl, tl, int)
DEF_HELPER_FLAGS_3(cc_compute_c, TCG_CALL_NO_RWG_SE, tl, tl, tl, int)
DEF_HELPER_0(lock, void)
DEF_HELPER_0(unlock, void)

31
target-i386/translate.c
View File

@ -882,13 +882,37 @@ static void gen_op_update_neg_cc(void)
/* compute all eflags to cc_src */
static void gen_compute_eflags(DisasContext *s)
{
TCGv zero, dst, src1;
int live, dead;
if (s->cc_op == CC_OP_EFLAGS) {
return;
}
TCGV_UNUSED(zero);
dst = cpu_cc_dst;
src1 = cpu_cc_src;
/* Take care to not read values that are not live. */
live = cc_op_live[s->cc_op] & ~USES_CC_SRCT;
dead = live ^ (USES_CC_DST | USES_CC_SRC);
if (dead) {
zero = tcg_const_tl(0);
if (dead & USES_CC_DST) {
dst = zero;
}
if (dead & USES_CC_SRC) {
src1 = zero;
}
}
gen_update_cc_op(s);
gen_helper_cc_compute_all(cpu_tmp2_i32, cpu_env, cpu_cc_op);
gen_helper_cc_compute_all(cpu_cc_src, dst, src1, cpu_cc_op);
set_cc_op(s, CC_OP_EFLAGS);
tcg_gen_extu_i32_tl(cpu_cc_src, cpu_tmp2_i32);
if (dead) {
tcg_temp_free(zero);
}
}
typedef struct CCPrepare {
@ -980,8 +1004,7 @@ static CCPrepare gen_prepare_eflags_c(DisasContext *s, TCGv reg)
/* The need to compute only C from CC_OP_DYNAMIC is important
in efficiently implementing e.g. INC at the start of a TB. */
gen_update_cc_op(s);
gen_helper_cc_compute_c(cpu_tmp2_i32, cpu_env, cpu_cc_op);
tcg_gen_extu_i32_tl(reg, cpu_tmp2_i32);
gen_helper_cc_compute_c(reg, cpu_cc_dst, cpu_cc_src, cpu_cc_op);
return (CCPrepare) { .cond = TCG_COND_NE, .reg = reg,
.mask = -1, .no_setcond = true };
}