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[PATCH 17/22] target/i386: Use gen_jmp_rel for loop and jecxz insns
From: |
Richard Henderson |
Subject: |
[PATCH 17/22] target/i386: Use gen_jmp_rel for loop and jecxz insns |
Date: |
Mon, 22 Aug 2022 16:33:13 -0700 |
With gen_jmp_rel, we may chain to the next tb
instead of merely writing to eip and exiting.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
target/i386/tcg/translate.c | 21 ++++++---------------
1 file changed, 6 insertions(+), 15 deletions(-)
diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 0a2ec85972..59e7596629 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -7242,24 +7242,18 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
case 0xe2: /* loop */
case 0xe3: /* jecxz */
{
- TCGLabel *l1, *l2, *l3;
-
- tval = (int8_t)insn_get(env, s, MO_8);
- tval += s->pc - s->cs_base;
- if (dflag == MO_16) {
- tval &= 0xffff;
- }
+ TCGLabel *l1, *l2;
+ int diff = (int8_t)insn_get(env, s, MO_8);
l1 = gen_new_label();
l2 = gen_new_label();
- l3 = gen_new_label();
gen_update_cc_op(s);
b &= 3;
switch(b) {
case 0: /* loopnz */
case 1: /* loopz */
gen_op_add_reg_im(s, s->aflag, R_ECX, -1);
- gen_op_jz_ecx(s, s->aflag, l3);
+ gen_op_jz_ecx(s, s->aflag, l2);
gen_jcc1(s, (JCC_Z << 1) | (b ^ 1), l1);
break;
case 2: /* loop */
@@ -7272,14 +7266,11 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
break;
}
- gen_set_label(l3);
- gen_update_eip_next(s);
- tcg_gen_br(l2);
+ gen_set_label(l2);
+ gen_jmp_rel(s, MO_32, 0, 1);
gen_set_label(l1);
- gen_jmp_im(s, tval);
- gen_set_label(l2);
- s->base.is_jmp = DISAS_EOB_ONLY;
+ gen_jmp_rel(s, dflag, diff, 0);
}
break;
case 0x130: /* wrmsr */
--
2.34.1
- [PATCH 04/22] target/i386: Create gen_update_eip_cur, (continued)
- [PATCH 04/22] target/i386: Create gen_update_eip_cur, Richard Henderson, 2022/08/22
- [PATCH 05/22] target/i386: Create gen_update_eip_next, Richard Henderson, 2022/08/22
- [PATCH 06/22] target/i386: Introduce DISAS_EOB*, Richard Henderson, 2022/08/22
- [PATCH 07/22] target/i386: Use DISAS_EOB* in gen_movl_seg_T0, Richard Henderson, 2022/08/22
- [PATCH 08/22] target/i386: Use DISAS_EOB_NEXT, Richard Henderson, 2022/08/22
- [PATCH 10/22] target/i386: Create cur_insn_len, cur_insn_len_i32, Richard Henderson, 2022/08/22
- [PATCH 09/22] target/i386: USe DISAS_EOB_ONLY, Richard Henderson, 2022/08/22
- [PATCH 13/22] target/i386: Truncate values for lcall_real to i32, Richard Henderson, 2022/08/22
- [PATCH 15/22] target/i386: Use DISAS_TOO_MANY to exit after gen_io_start, Richard Henderson, 2022/08/22
- [PATCH 16/22] target/i386: Create gen_jmp_rel, Richard Henderson, 2022/08/22
- [PATCH 17/22] target/i386: Use gen_jmp_rel for loop and jecxz insns,
Richard Henderson <=
- [PATCH 11/22] target/i386: Remove cur_eip, next_eip arguments to gen_repz*, Richard Henderson, 2022/08/22
- [PATCH 20/22] target/i386: Use gen_jmp_rel for DISAS_TOO_MANY, Richard Henderson, 2022/08/22
- [PATCH 12/22] target/i386: Introduce DISAS_JUMP, Richard Henderson, 2022/08/22
- [PATCH 19/22] target/i386: Use gen_jmp_rel for gen_repz*, Richard Henderson, 2022/08/22
- [PATCH 18/22] target/i386: Use gen_jmp_rel for gen_jcc, Richard Henderson, 2022/08/22
- [PATCH 22/22] target/i386: Enable TARGET_TB_PCREL, Richard Henderson, 2022/08/22
- [PATCH 21/22] target/i386: Create gen_eip_cur, Richard Henderson, 2022/08/22
- [PATCH 14/22] target/i386: Create eip_next_*, Richard Henderson, 2022/08/22