On Tue, Sep 6, 2022 at 12:09 PM Richard Henderson
<richard.hender...@linaro.org> wrote:
>
> 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.hender...@linaro.org>
See comment on the previous patch.
Paolo
> ---
> 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 07c7764649..fdd17c3cf3 100644
> --- a/target/i386/tcg/translate.c
> +++ b/target/i386/tcg/translate.c
> @@ -7355,24 +7355,18 @@ 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 */
> @@ -7385,14 +7379,11 @@ 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
>
