| Message ID | 1349526621-13939-10-git-send-email-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Sat, Oct 6, 2012 at 12:30 PM, Paolo Bonzini <pbonzini@redhat.com> wrote: > ZF, SF and PF can always be computed from CC_DST except in the > CC_OP_EFLAGS case (and CC_OP_DYNAMIC, which just resolves to CC_OP_EFLAGS > in gen_compute_eflags). Use setcond to compute ZF and SF. > > We could also use a table lookup to compute PF. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Blue Swirl <blauwirbel@gmail.com> > --- > target-i386/translate.c | 28 ++++++++++++++++++++++------ > 1 file modificato, 22 inserzioni(+), 6 rimozioni(-) > > diff --git a/target-i386/translate.c b/target-i386/translate.c > index 09512c3..daa36c1 100644 > --- a/target-i386/translate.c > +++ b/target-i386/translate.c > @@ -859,9 +859,17 @@ static void gen_compute_eflags_p(DisasContext *s, TCGv reg) > /* compute eflags.S to reg */ > static void gen_compute_eflags_s(DisasContext *s, TCGv reg) > { > - gen_compute_eflags(s); > - tcg_gen_shri_tl(reg, cpu_cc_src, 7); > - tcg_gen_andi_tl(reg, reg, 1); > + if (s->cc_op == CC_OP_DYNAMIC) { > + gen_compute_eflags(s); > + } > + if (s->cc_op == CC_OP_EFLAGS) { > + tcg_gen_shri_tl(reg, cpu_cc_src, 7); > + tcg_gen_andi_tl(reg, reg, 1); > + } else { A comment would be nice here, like something extracted from commit message. > + int size = (s->cc_op - CC_OP_ADDB) & 3; > + gen_ext_tl(reg, cpu_cc_dst, size, true); > + tcg_gen_setcondi_tl(TCG_COND_LT, reg, reg, 0); > + } > } > > /* compute eflags.O to reg */ > @@ -875,9 +883,17 @@ static void gen_compute_eflags_o(DisasContext *s, TCGv reg) > /* compute eflags.Z to reg */ > static void gen_compute_eflags_z(DisasContext *s, TCGv reg) > { > - gen_compute_eflags(s); > - tcg_gen_shri_tl(reg, cpu_cc_src, 6); > - tcg_gen_andi_tl(reg, reg, 1); > + if (s->cc_op == CC_OP_DYNAMIC) { > + gen_compute_eflags(s); > + } > + if (s->cc_op == CC_OP_EFLAGS) { > + tcg_gen_shri_tl(reg, cpu_cc_src, 6); > + tcg_gen_andi_tl(reg, reg, 1); > + } else { Ditto. > + int size = (s->cc_op - CC_OP_ADDB) & 3; > + gen_ext_tl(reg, cpu_cc_dst, size, false); > + tcg_gen_setcondi_tl(TCG_COND_EQ, reg, cpu_cc_dst, 0); > + } > } > > static inline void gen_setcc_slow_T0(DisasContext *s, int jcc_op) > -- > 1.7.12.1 > > >
On 10/06/2012 05:30 AM, Paolo Bonzini wrote: > ZF, SF and PF can always be computed from CC_DST except in the > CC_OP_EFLAGS case (and CC_OP_DYNAMIC, which just resolves to CC_OP_EFLAGS > in gen_compute_eflags). Use setcond to compute ZF and SF. > > We could also use a table lookup to compute PF. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net> r~
On 10/06/2012 05:30 AM, Paolo Bonzini wrote: > + int size = (s->cc_op - CC_OP_ADDB) & 3; > + gen_ext_tl(reg, cpu_cc_dst, size, false); > + tcg_gen_setcondi_tl(TCG_COND_EQ, reg, cpu_cc_dst, 0); I take that back. Should be (EQ, reg, reg, 0) here; you've dropped the extension on the floor. r~
Il 09/10/2012 21:16, Richard Henderson ha scritto: >> > + int size = (s->cc_op - CC_OP_ADDB) & 3; >> > + gen_ext_tl(reg, cpu_cc_dst, size, false); >> > + tcg_gen_setcondi_tl(TCG_COND_EQ, reg, cpu_cc_dst, 0); > I take that back. Should be (EQ, reg, reg, 0) here; > you've dropped the extension on the floor. More precisely it should be: TCGv t0 = gen_ext_tl(reg, cpu_cc_dst, size, false); tcg_gen_setcondi_tl(TCG_COND_EQ, reg, t0, 0); and similarly for SF. Paolo
diff --git a/target-i386/translate.c b/target-i386/translate.c index 09512c3..daa36c1 100644 --- a/target-i386/translate.c +++ b/target-i386/translate.c @@ -859,9 +859,17 @@ static void gen_compute_eflags_p(DisasContext *s, TCGv reg) /* compute eflags.S to reg */ static void gen_compute_eflags_s(DisasContext *s, TCGv reg) { - gen_compute_eflags(s); - tcg_gen_shri_tl(reg, cpu_cc_src, 7); - tcg_gen_andi_tl(reg, reg, 1); + if (s->cc_op == CC_OP_DYNAMIC) { + gen_compute_eflags(s); + } + if (s->cc_op == CC_OP_EFLAGS) { + tcg_gen_shri_tl(reg, cpu_cc_src, 7); + tcg_gen_andi_tl(reg, reg, 1); + } else { + int size = (s->cc_op - CC_OP_ADDB) & 3; + gen_ext_tl(reg, cpu_cc_dst, size, true); + tcg_gen_setcondi_tl(TCG_COND_LT, reg, reg, 0); + } } /* compute eflags.O to reg */ @@ -875,9 +883,17 @@ static void gen_compute_eflags_o(DisasContext *s, TCGv reg) /* compute eflags.Z to reg */ static void gen_compute_eflags_z(DisasContext *s, TCGv reg) { - gen_compute_eflags(s); - tcg_gen_shri_tl(reg, cpu_cc_src, 6); - tcg_gen_andi_tl(reg, reg, 1); + if (s->cc_op == CC_OP_DYNAMIC) { + gen_compute_eflags(s); + } + if (s->cc_op == CC_OP_EFLAGS) { + tcg_gen_shri_tl(reg, cpu_cc_src, 6); + tcg_gen_andi_tl(reg, reg, 1); + } else { + int size = (s->cc_op - CC_OP_ADDB) & 3; + gen_ext_tl(reg, cpu_cc_dst, size, false); + tcg_gen_setcondi_tl(TCG_COND_EQ, reg, cpu_cc_dst, 0); + } } static inline void gen_setcc_slow_T0(DisasContext *s, int jcc_op)
ZF, SF and PF can always be computed from CC_DST except in the CC_OP_EFLAGS case (and CC_OP_DYNAMIC, which just resolves to CC_OP_EFLAGS in gen_compute_eflags). Use setcond to compute ZF and SF. We could also use a table lookup to compute PF. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- target-i386/translate.c | 28 ++++++++++++++++++++++------ 1 file modificato, 22 inserzioni(+), 6 rimozioni(-)