@samitouri / QOSamiQemu / commits / 389a4189a0

target/i386/tcg: do not reuse cc_srcT

Use a different temporary for every instruction that uses it in the translation block. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Paolo Bonzini committed Jun 19, 2026 at 08:05 UTC 389a4189a07ddd8a740ede94da7b59b67a374cbb

2 files changed +11 -6

target/i386/tcg/emit.c.inc

+7 -4

@@ -1699,6 +1699,7 @@ static void gen_CMPccXADD(DisasContext *s, X86DecodedInsn *decode)

1699 * - s->cc_srcT: memory operand (lhs for comparison)

1700 * - cmpv: rhs for comparison

1701 */

1702 + s->cc_srcT = tcg_temp_new();

1703 gen_set_label(label_top);

1704 gen_op_ld_v(s, ot_full, s->cc_srcT, s->A0);

1705 tcg_gen_sub_tl(s->T0, s->cc_srcT, cmpv);

@@ -1800,11 +1801,12 @@ static void gen_CMPXCHG(DisasContext *s, X86DecodedInsn *decode)

1801 dest = gen_op_deposit_reg_v(s, ot, R_EAX, s->T0, oldv);

1802 tcg_gen_movcond_tl(TCG_COND_NE, dest, oldv, cmpv, s->T0, dest);

1803

1803 - tcg_gen_mov_tl(s->cc_srcT, cmpv);

1804 - tcg_gen_sub_tl(cmpv, cmpv, oldv);

1805 - decode->cc_dst = cmpv;

1804 + s->cc_srcT = cmpv;

1805 + decode->cc_dst = tcg_temp_new();

1806 decode->cc_src = oldv;

1807 decode->cc_op = CC_OP_SUBB + ot;

1808 +

1809 + tcg_gen_sub_tl(decode->cc_dst, cmpv, oldv);

1810 }

1811

1812 static void gen_CMPXCHG16B(DisasContext *s, X86DecodedInsn *decode)

@@ -2722,7 +2724,7 @@ static void gen_NEG(DisasContext *s, X86DecodedInsn *decode)

2724

2725 decode->cc_dst = s->T0;

2726 decode->cc_src = oldv;

2725 - tcg_gen_movi_tl(s->cc_srcT, 0);

2727 + s->cc_srcT = tcg_constant_tl(0);

2728 decode->cc_op = CC_OP_SUBB + ot;

2729 }

2730

@@ -4114,6 +4116,7 @@ static void gen_SUB(DisasContext *s, X86DecodedInsn *decode)

4116 {

4117 MemOp ot = decode->op[1].ot;

4118

4119 + s->cc_srcT = tcg_temp_new();

4120 if (s->prefix & PREFIX_LOCK) {

4121 tcg_gen_neg_tl(s->T0, s->T1);

4122 tcg_gen_atomic_fetch_add_tl(s->cc_srcT, s->A0, s->T0,

target/i386/tcg/translate.c

+4 -2

@@ -342,7 +342,7 @@ static void set_cc_op_1(DisasContext *s, CCOp op, bool dirty)

342 tcg_gen_discard_tl(cpu_cc_src2);

343 }

344 if (dead & USES_CC_SRCT) {

345 - tcg_gen_discard_tl(s->cc_srcT);

345 + s->cc_srcT = NULL;

346 }

347

348 if (dirty && s->cc_op == CC_OP_DYNAMIC) {

@@ -1236,6 +1236,7 @@ static void gen_lods(DisasContext *s, MemOp ot, TCGv dshift)

1236

1237 static void gen_scas(DisasContext *s, MemOp ot, TCGv dshift)

1238 {

1239 + s->cc_srcT = tcg_temp_new();

1240 gen_string_movl_A0_EDI(s);

1241 gen_op_ld_v(s, ot, s->T1, s->A0);

1242 tcg_gen_mov_tl(cpu_cc_src, s->T1);

@@ -1248,6 +1249,7 @@ static void gen_scas(DisasContext *s, MemOp ot, TCGv dshift)

1249

1250 static void gen_cmps(DisasContext *s, MemOp ot, TCGv dshift)

1251 {

1252 + s->cc_srcT = tcg_temp_new();

1253 gen_string_movl_A0_EDI(s);

1254 gen_op_ld_v(s, ot, s->T1, s->A0);

1255 gen_string_movl_A0_ESI(s);

@@ -3484,7 +3486,7 @@ static void i386_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cpu)

3486 dc->T1 = tcg_temp_new();

3487 dc->A0 = tcg_temp_new();

3488

3487 - dc->cc_srcT = tcg_temp_new();

3489 + dc->cc_srcT = NULL;

3490 }

3491

3492 static void i386_tr_tb_start(DisasContextBase *db, CPUState *cpu)