| Message ID | 20220906100932.343523-19-richard.henderson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | target/i386: pc-relative translation blocks | expand |
On Tue, Sep 6, 2022 at 12:09 PM Richard Henderson <richard.henderson@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.henderson@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 >
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 */
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(-)