[PATCH] x86: Require TARGET_HIMODE_MATH for HImode atomic bit expanders

H.J. Lu hjl.tools@gmail.com
Fri Nov 12 15:55:26 GMT 2021


On Fri, Nov 12, 2021 at 7:34 AM Jakub Jelinek <jakub@redhat.com> wrote:
>
> On Fri, Nov 12, 2021 at 07:29:03AM -0800, H.J. Lu wrote:
> > Check optab before transforming equivalent, but slighly different cases
> > to their canonical forms in optimize_atomic_bit_test_and and require
> > TARGET_HIMODE_MATH in HImode atomic bit expanders.
> >
> > gcc/
> >
> >       PR target/103205
> >       * tree-ssa-ccp.c (optimize_atomic_bit_test_and): Check optab
> >       before transforming equivalent, but slighly different cases to
> >       their canonical forms.
> >       * config/i386/sync.md (atomic_bit_test_and_set<mode>): Require
> >       TARGET_HIMODE_MATH for HImode.
> >       (atomic_bit_test_and_complement<mode>): Likewise.
> >       (atomic_bit_test_and_reset<mode>): Likewise.
> >
> > gcc/testsuite/
> >
> >       PR target/103205
> >       * gcc.target/i386/pr103205-1a.c: New test.
> >       * gcc.target/i386/pr103205-1b.c: Likewise.
> >       * gcc.target/i386/pr103205-2a.c: Likewise.
> >       * gcc.target/i386/pr103205-2b.c: Likewise.
> >       * gcc.target/i386/pr103205-3.c: Likewise.
> >       * gcc.target/i386/pr103205-4.c: Likewise.
>
> Why?  When one uses 16-bit atomics, no matter what he does there will be
> some HImode math (at least the atomic instruction).  And the rest can be
> dealt with.

I withdrew my patch.

> I have following patch queued for testing for this...
>
> 2021-11-12  Jakub Jelinek  <jakub@redhat.com>
>
>         PR target/103205
>         * config/i386/sync.md (atomic_bit_test_and_set<mode>,
>         atomic_bit_test_and_complement<mode>,
>         atomic_bit_test_and_reset<mode>): Use OPTAB_WIDEN instead of
>         OPTAB_DIRECT.
>
>         * gcc.target/i386/pr103205.c: New test.

Can you include my tests?  Or you can leave out your test and I can check
in my tests after your fix has been checked in.

Thanks.

> --- gcc/config/i386/sync.md.jj  2021-10-04 19:53:01.025005548 +0200
> +++ gcc/config/i386/sync.md     2021-11-12 15:27:47.387273428 +0100
> @@ -726,7 +726,7 @@ (define_expand "atomic_bit_test_and_set<
>    rtx result = convert_modes (<MODE>mode, QImode, tem, 1);
>    if (operands[4] == const0_rtx)
>      result = expand_simple_binop (<MODE>mode, ASHIFT, result,
> -                                 operands[2], operands[0], 0, OPTAB_DIRECT);
> +                                 operands[2], operands[0], 0, OPTAB_WIDEN);
>    if (result != operands[0])
>      emit_move_insn (operands[0], result);
>    DONE;
> @@ -763,7 +763,7 @@ (define_expand "atomic_bit_test_and_comp
>    rtx result = convert_modes (<MODE>mode, QImode, tem, 1);
>    if (operands[4] == const0_rtx)
>      result = expand_simple_binop (<MODE>mode, ASHIFT, result,
> -                                 operands[2], operands[0], 0, OPTAB_DIRECT);
> +                                 operands[2], operands[0], 0, OPTAB_WIDEN);
>    if (result != operands[0])
>      emit_move_insn (operands[0], result);
>    DONE;
> @@ -801,7 +801,7 @@ (define_expand "atomic_bit_test_and_rese
>    rtx result = convert_modes (<MODE>mode, QImode, tem, 1);
>    if (operands[4] == const0_rtx)
>      result = expand_simple_binop (<MODE>mode, ASHIFT, result,
> -                                 operands[2], operands[0], 0, OPTAB_DIRECT);
> +                                 operands[2], operands[0], 0, OPTAB_WIDEN);
>    if (result != operands[0])
>      emit_move_insn (operands[0], result);
>    DONE;
> --- gcc/testsuite/gcc.target/i386/pr103205.c.jj 2021-11-12 15:47:21.218380790 +0100
> +++ gcc/testsuite/gcc.target/i386/pr103205.c    2021-11-12 15:46:39.546980182 +0100
> @@ -0,0 +1,11 @@
> +/* PR target/103205 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mtune-ctrl=^himode_math" } */
> +
> +unsigned short a;
> +
> +unsigned short
> +foo (void)
> +{
> +  return __sync_fetch_and_and (&a, ~1) & 1;
> +}
>
>
>         Jakub
>


-- 
H.J.


More information about the Gcc-patches mailing list