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target/i386: cpu_load_eflags already sets cc_op 

No need to set it again at the end of the translation block, cc_op_dirty
can be set to false.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2024-05-16 23:08:40 +02:00
parent f6ac77eab6
commit a0625efd4d
2 changed files with 25 additions and 14 deletions
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2
target/i386/tcg/emit.c.inc
View File

@ -1883,7 +1883,7 @@ static void gen_IRET(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
gen_helper_iret_protected(tcg_env, tcg_constant_i32(s->dflag - 1),
eip_next_i32(s));
}
set_cc_op(s, CC_OP_EFLAGS);
assume_cc_op(s, CC_OP_EFLAGS);
s->base.is_jmp = DISAS_EOB_ONLY;
}

37
target/i386/tcg/translate.c
View File

@ -309,7 +309,7 @@ static const uint8_t cc_op_live[CC_OP_NB] = {
[CC_OP_POPCNT] = USES_CC_SRC,
};
static void set_cc_op(DisasContext *s, CCOp op)
static void set_cc_op_1(DisasContext *s, CCOp op, bool dirty)
{
int dead;
@ -332,20 +332,27 @@ static void set_cc_op(DisasContext *s, CCOp op)
tcg_gen_discard_tl(s->cc_srcT);
}
if (op == CC_OP_DYNAMIC) {
/* The DYNAMIC setting is translator only, and should never be
stored. Thus we always consider it clean. */
s->cc_op_dirty = false;
} else {
/* Discard any computed CC_OP value (see shifts). */
if (s->cc_op == CC_OP_DYNAMIC) {
tcg_gen_discard_i32(cpu_cc_op);
}
s->cc_op_dirty = true;
if (dirty && s->cc_op == CC_OP_DYNAMIC) {
tcg_gen_discard_i32(cpu_cc_op);
}
s->cc_op_dirty = dirty;
s->cc_op = op;
}
static void set_cc_op(DisasContext *s, CCOp op)
{
/*
* The DYNAMIC setting is translator only, everything else
* will be spilled later.
*/
set_cc_op_1(s, op, op != CC_OP_DYNAMIC);
}
static void assume_cc_op(DisasContext *s, CCOp op)
{
set_cc_op_1(s, op, false);
}
static void gen_update_cc_op(DisasContext *s)
{
if (s->cc_op_dirty) {
@ -3554,6 +3561,10 @@ static void disas_insn_old(DisasContext *s, CPUState *cpu, int b)
gen_update_cc_op(s);
gen_update_eip_cur(s);
gen_helper_syscall(tcg_env, cur_insn_len_i32(s));
/* condition codes are modified only in long mode */
if (LMA(s)) {
assume_cc_op(s, CC_OP_EFLAGS);
}
/* TF handling for the syscall insn is different. The TF bit is checked
after the syscall insn completes. This allows #DB to not be
generated after one has entered CPL0 if TF is set in FMASK. */
@ -3570,7 +3581,7 @@ static void disas_insn_old(DisasContext *s, CPUState *cpu, int b)
gen_helper_sysret(tcg_env, tcg_constant_i32(dflag - 1));
/* condition codes are modified only in long mode */
if (LMA(s)) {
set_cc_op(s, CC_OP_EFLAGS);
assume_cc_op(s, CC_OP_EFLAGS);
}
/* TF handling for the sysret insn is different. The TF bit is
checked after the sysret insn completes. This allows #DB to be
@ -4489,7 +4500,7 @@ static void disas_insn_old(DisasContext *s, CPUState *cpu, int b)
g_assert_not_reached();
#else
gen_helper_rsm(tcg_env);
set_cc_op(s, CC_OP_EFLAGS);
assume_cc_op(s, CC_OP_EFLAGS);
#endif /* CONFIG_USER_ONLY */
s->base.is_jmp = DISAS_EOB_ONLY;
break;