| Message ID | 20240620095419.386958-3-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | target/i386: make decoding entirely table based | expand |
On 6/20/24 02:54, Paolo Bonzini wrote: > Handle it like the other arithmetic cc_ops. This simplifies a > bit the implementation of bit test instructions. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > target/i386/cpu.h | 13 +++++++++++-- > target/i386/tcg/translate.c | 3 +-- > 2 files changed, 12 insertions(+), 4 deletions(-) > > diff --git a/target/i386/cpu.h b/target/i386/cpu.h > index f54cd93b3f9..8504a7998fd 100644 > --- a/target/i386/cpu.h > +++ b/target/i386/cpu.h > @@ -1275,6 +1275,7 @@ typedef enum { > CC_OP_ADCX, /* CC_DST = C, CC_SRC = rest. */ > CC_OP_ADOX, /* CC_SRC2 = O, CC_SRC = rest. */ > CC_OP_ADCOX, /* CC_DST = C, CC_SRC2 = O, CC_SRC = rest. */ > + CC_OP_CLR, /* Z and P set, all other flags clear. */ > > CC_OP_MULB, /* modify all flags, C, O = (CC_SRC != 0) */ > CC_OP_MULW, > @@ -1331,8 +1332,16 @@ typedef enum { > CC_OP_BMILGL, > CC_OP_BMILGQ, > > - CC_OP_CLR, /* Z set, all other flags clear. */ > - CC_OP_POPCNT, /* Z via CC_DST, all other flags clear. */ > + /* > + * Note that only CC_OP_POPCNT (i.e. the one with MO_TL size) > + * is used or implemented, because the translation needs > + * to zero-extend CC_DST anyway. > + */ > + CC_OP_POPCNTB__, /* Z via CC_DST, all other flags clear. */ > + CC_OP_POPCNTW__, > + CC_OP_POPCNTL__, > + CC_OP_POPCNTQ__, > + CC_OP_POPCNT = sizeof(target_ulong) == 8 ? CC_OP_POPCNTQ__ : CC_OP_POPCNTL__, > > CC_OP_NB, > } CCOp; > diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c > index f32cda4e169..934c514e64f 100644 > --- a/target/i386/tcg/translate.c > +++ b/target/i386/tcg/translate.c > @@ -1019,8 +1019,6 @@ static CCPrepare gen_prepare_eflags_z(DisasContext *s, TCGv reg) > .imm = CC_Z }; > case CC_OP_CLR: > return (CCPrepare) { .cond = TCG_COND_ALWAYS }; > - case CC_OP_POPCNT: > - return (CCPrepare) { .cond = TCG_COND_EQ, .reg = cpu_cc_src }; The previous patch needs to have changed this to dst. Otherwise, Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/target/i386/cpu.h b/target/i386/cpu.h index f54cd93b3f9..8504a7998fd 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1275,6 +1275,7 @@ typedef enum { CC_OP_ADCX, /* CC_DST = C, CC_SRC = rest. */ CC_OP_ADOX, /* CC_SRC2 = O, CC_SRC = rest. */ CC_OP_ADCOX, /* CC_DST = C, CC_SRC2 = O, CC_SRC = rest. */ + CC_OP_CLR, /* Z and P set, all other flags clear. */ CC_OP_MULB, /* modify all flags, C, O = (CC_SRC != 0) */ CC_OP_MULW, @@ -1331,8 +1332,16 @@ typedef enum { CC_OP_BMILGL, CC_OP_BMILGQ, - CC_OP_CLR, /* Z set, all other flags clear. */ - CC_OP_POPCNT, /* Z via CC_DST, all other flags clear. */ + /* + * Note that only CC_OP_POPCNT (i.e. the one with MO_TL size) + * is used or implemented, because the translation needs + * to zero-extend CC_DST anyway. + */ + CC_OP_POPCNTB__, /* Z via CC_DST, all other flags clear. */ + CC_OP_POPCNTW__, + CC_OP_POPCNTL__, + CC_OP_POPCNTQ__, + CC_OP_POPCNT = sizeof(target_ulong) == 8 ? CC_OP_POPCNTQ__ : CC_OP_POPCNTL__, CC_OP_NB, } CCOp; diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c index f32cda4e169..934c514e64f 100644 --- a/target/i386/tcg/translate.c +++ b/target/i386/tcg/translate.c @@ -1019,8 +1019,6 @@ static CCPrepare gen_prepare_eflags_z(DisasContext *s, TCGv reg) .imm = CC_Z }; case CC_OP_CLR: return (CCPrepare) { .cond = TCG_COND_ALWAYS }; - case CC_OP_POPCNT: - return (CCPrepare) { .cond = TCG_COND_EQ, .reg = cpu_cc_src }; default: { MemOp size = (s->cc_op - CC_OP_ADDB) & 3; @@ -3177,6 +3175,7 @@ static void disas_insn_old(DisasContext *s, CPUState *cpu, int b) case CC_OP_SHLB ... CC_OP_SHLQ: case CC_OP_SARB ... CC_OP_SARQ: case CC_OP_BMILGB ... CC_OP_BMILGQ: + case CC_OP_POPCNT: /* Z was going to be computed from the non-zero status of CC_DST. We can get that same Z value (and the new C value) by leaving CC_DST alone, setting CC_SRC, and using a CC_OP_SAR of the
Handle it like the other arithmetic cc_ops. This simplifies a bit the implementation of bit test instructions. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- target/i386/cpu.h | 13 +++++++++++-- target/i386/tcg/translate.c | 3 +-- 2 files changed, 12 insertions(+), 4 deletions(-)