Re: [PATCH] [i386] recognize bzhi pattern when there's zero_extendsidi.

[Hongtao Liu <crazylht@gmail.com>]

On Tue, May 17, 2022 at 6:07 PM Uros Bizjak via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Tue, May 17, 2022 at 5:06 AM liuhongt <hongtao.liu@intel.com> wrote:
> >
> > backend has
> >
> > 16550(define_insn "*bmi2_bzhi_<mode>3_2"
> > 16551  [(set (match_operand:SWI48 0 "register_operand" "=r")
> > 16552        (and:SWI48
> > 16553          (plus:SWI48
> > 16554            (ashift:SWI48 (const_int 1)
> > 16555                          (match_operand:QI 2 "register_operand" "r"))
> > 16556            (const_int -1))
> > 16557          (match_operand:SWI48 1 "nonimmediate_operand" "rm")))
> > 16558   (clobber (reg:CC FLAGS_REG))]
> > 16559  "TARGET_BMI2"
> > 16560  "bzhi\t{%<k>2, %1, %0|%0, %1, %<k>2}"
> > 16561  [(set_attr "type" "bitmanip")
> > 16562   (set_attr "prefix" "vex")
> > 16563   (set_attr "mode" "<MODE>")])
> >
> > But there's extra zero_extend in pattern match.
> >
> > 424Failed to match this instruction:
> > 425(parallel [
> > 426        (set (reg:DI 90)
> > 427            (zero_extend:DI (and:SI (plus:SI (ashift:SI (const_int 1 [0x1])
> > 428                            (subreg:QI (reg:SI 98) 0))
> > 429                        (const_int -1 [0xffffffffffffffff]))
> > 430                    (subreg:SI (reg:DI 95) 0))))
> > 431        (clobber (reg:CC 17 flags))
> > 432    ])
> >
> > Add new define_insn for it.
> >
> >
> > Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}..
> > Ok for trunk?
> >
> > gcc/ChangeLog:
> >
> >         PR target/104375
> >         * config/i386/i386.md (*bmi2_bzhi_zero_extendsidi_4): New
> >         define_insn.
> >
> > gcc/testsuite/ChangeLog:
> >
> >         * gcc.target/i386/pr104375.c: New test.
>
> OK with a nit below.
Thanks for the review, changed and committed.
>
> Thanks,
> Uros.
>
> > ---
> >  gcc/config/i386/i386.md                  | 16 ++++++++++++++++
> >  gcc/testsuite/gcc.target/i386/pr104375.c |  9 +++++++++
> >  2 files changed, 25 insertions(+)
> >  create mode 100644 gcc/testsuite/gcc.target/i386/pr104375.c
> >
> > diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> > index f9c06ff302a..ec7bdd04947 100644
> > --- a/gcc/config/i386/i386.md
> > +++ b/gcc/config/i386/i386.md
> > @@ -16636,6 +16636,22 @@ (define_insn "*bmi2_bzhi_<mode>3_3"
> >     (set_attr "prefix" "vex")
> >     (set_attr "mode" "<MODE>")])
> >
> > +(define_insn "*bmi2_bzhi_zero_extendsidi_4"
> > +  [(set (match_operand:DI 0 "register_operand" "=r")
> > +       (zero_extend:DI
> > +         (and:SI
> > +           (plus:SI
> > +             (ashift:SI (const_int 1)
> > +                        (match_operand:QI 2 "register_operand" "r"))
> > +             (const_int -1))
> > +           (match_operand:SI 1 "nonimmediate_operand" "rm"))))
> > +   (clobber (reg:CC FLAGS_REG))]
> > +  "TARGET_BMI2 && TARGET_64BIT"
>
> Please put TARGET_64BIT first here.
>
> > +  "bzhi\t{%q2, %q1, %q0|%q0, %q1, %q2}"
> > +  [(set_attr "type" "bitmanip")
> > +   (set_attr "prefix" "vex")
> > +   (set_attr "mode" "DI")])
> > +
> >  (define_insn "bmi2_pdep_<mode>3"
> >    [(set (match_operand:SWI48 0 "register_operand" "=r")
> >          (unspec:SWI48 [(match_operand:SWI48 1 "register_operand" "r")
> > diff --git a/gcc/testsuite/gcc.target/i386/pr104375.c b/gcc/testsuite/gcc.target/i386/pr104375.c
> > new file mode 100644
> > index 00000000000..5c9f511da5c
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr104375.c
> > @@ -0,0 +1,9 @@
> > +#/* { dg-do compile { target { ! ia32 } } } */
> > +/* { dg-options "-mbmi2 -O2" } */
> > +/* { dg-final { scan-assembler-times {(?n)shrx[\t ]+} 1 } } */
> > +/* { dg-final { scan-assembler-times {(?n)bzhi[\t ]+} 1 } } */
> > +
> > +unsigned long long bextr_u64(unsigned long long w, unsigned off, unsigned int len)
> > +{
> > +    return (w >> off) & ((1U << len) - 1U);
> > +}
> > --
> > 2.18.1
> >



-- 
BR,
Hongtao