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target/i386: Wrap cc_op_live with a validity check

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Assert that op is known and that cc_op_live_ is populated.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Richard Henderson 2024-07-01 11:08:50 +02:00 committed by Paolo Bonzini
parent f359b2fb71
commit 1f7f72bdc4
4 changed files with 21 additions and 7 deletions
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1
target/i386/cpu.h
View File

@ -1380,7 +1380,6 @@ typedef enum {
#define CC_OP_LAST_BWLQ CC_OP_POPCNTQ__
CC_OP_DYNAMIC, /* must use dynamic code to get cc_op */
CC_OP_NB,
} CCOp;
/* See X86DecodedInsn.cc_op, using int8_t. */

2
target/i386/tcg/decode-new.c.inc
View File

@ -2865,7 +2865,7 @@ static void disas_insn(DisasContext *s, CPUState *cpu)
tcg_gen_mov_i32(cpu_cc_op, decode.cc_op_dynamic);
}
set_cc_op(s, decode.cc_op);
cc_live = cc_op_live[decode.cc_op];
cc_live = cc_op_live(decode.cc_op);
} else {
cc_live = 0;
}

4
target/i386/tcg/emit.c.inc
View File

@ -3777,13 +3777,13 @@ static void gen_shift_dynamic_flags(DisasContext *s, X86DecodedInsn *decode, TCG
decode->cc_op_dynamic = tcg_temp_new_i32();
assert(decode->cc_dst == s->T0);
if (cc_op_live[s->cc_op] & USES_CC_DST) {
if (cc_op_live(s->cc_op) & USES_CC_DST) {
decode->cc_dst = tcg_temp_new();
tcg_gen_movcond_tl(TCG_COND_EQ, decode->cc_dst, count, tcg_constant_tl(0),
cpu_cc_dst, s->T0);
}
if (cc_op_live[s->cc_op] & USES_CC_SRC) {
if (cc_op_live(s->cc_op) & USES_CC_SRC) {
tcg_gen_movcond_tl(TCG_COND_EQ, decode->cc_src, count, tcg_constant_tl(0),
cpu_cc_src, decode->cc_src);
}

21
target/i386/tcg/translate.c
View File

@ -291,7 +291,7 @@ enum {
};
/* Bit set if the global variable is live after setting CC_OP to X. */
static const uint8_t cc_op_live[CC_OP_NB] = {
static const uint8_t cc_op_live_[] = {
[CC_OP_DYNAMIC] = USES_CC_DST | USES_CC_SRC | USES_CC_SRC2,
[CC_OP_EFLAGS] = USES_CC_SRC,
[CC_OP_MULB ... CC_OP_MULQ] = USES_CC_DST | USES_CC_SRC,
@ -312,6 +312,21 @@ static const uint8_t cc_op_live[CC_OP_NB] = {
[CC_OP_POPCNT] = USES_CC_DST,
};
static uint8_t cc_op_live(CCOp op)
{
uint8_t result;
assert(op >= 0 && op < ARRAY_SIZE(cc_op_live_));
/*
* Check that the array is fully populated. A zero entry would correspond
* to a fixed value of EFLAGS, which can be obtained with CC_OP_EFLAGS
* as well.
*/
result = cc_op_live_[op];
assert(result);
return result;
}
static void set_cc_op_1(DisasContext *s, CCOp op, bool dirty)
{
int dead;
@ -321,7 +336,7 @@ static void set_cc_op_1(DisasContext *s, CCOp op, bool dirty)
}
/* Discard CC computation that will no longer be used. */
dead = cc_op_live[s->cc_op] & ~cc_op_live[op];
dead = cc_op_live(s->cc_op) & ~cc_op_live(op);
if (dead & USES_CC_DST) {
tcg_gen_discard_tl(cpu_cc_dst);
}
@ -808,7 +823,7 @@ static void gen_mov_eflags(DisasContext *s, TCGv reg)
src2 = cpu_cc_src2;
/* Take care to not read values that are not live. */
live = cc_op_live[s->cc_op] & ~USES_CC_SRCT;
live = cc_op_live(s->cc_op) & ~USES_CC_SRCT;
dead = live ^ (USES_CC_DST | USES_CC_SRC | USES_CC_SRC2);
if (dead) {
TCGv zero = tcg_constant_tl(0);