On Fri, Oct 4, 2024 at 12:07 PM Jakub Jelinek <ja...@redhat.com> wrote:
>
> Hi!
>
> While *minmax<mode>3_1 correctly uses
> if (MEM_P (operands[1]))
> operands[1] = force_reg (<MODE>mode, operands[1]);
> to ensure operands[1] is not a MEM, *minmax<mode>3_2 does it wrongly
> by calling force_reg but ignoring its return value.
>
> The following borderingly obvious patch fixes that, bootstrapped/regtested
> on x86_64-linux and i686-linux, ok for trunk?
>
> Didn't find similar other errors in the backend with force_reg calls.
>
> 2024-10-04 Jakub Jelinek <ja...@redhat.com>
>
> PR target/116925
> * config/i386/sse.md (*minmax<mode>3_2): Assign force_reg result
> back to operands[2] instead of throwing it away.
>
> * g++.target/i386/avx-pr116925.C: New test.
OK, even obvious.
Thanks,
Uros.
>
> --- gcc/config/i386/sse.md.jj 2024-10-01 09:38:57.000000000 +0200
> +++ gcc/config/i386/sse.md 2024-10-03 17:33:12.071507421 +0200
> @@ -3269,7 +3269,7 @@ (define_insn_and_split "*minmax<mode>3_2
> u = UNSPEC_IEEE_MAX;
>
> if (MEM_P (operands[2]))
> - force_reg (<MODE>mode, operands[2]);
> + operands[2] = force_reg (<MODE>mode, operands[2]);
> rtvec v = gen_rtvec (2, operands[2], operands[1]);
> rtx tmp = gen_rtx_UNSPEC (<MODE>mode, v, u);
> emit_move_insn (operands[0], tmp);
> --- gcc/testsuite/g++.target/i386/avx-pr116925.C.jj 2024-10-03
> 17:36:10.124061111 +0200
> +++ gcc/testsuite/g++.target/i386/avx-pr116925.C 2024-10-03
> 17:35:26.805656671 +0200
> @@ -0,0 +1,12 @@
> +// PR target/116925
> +// { dg-do compile }
> +// { dg-options "-O2 -mavx -ffloat-store" }
> +
> +typedef float V __attribute__((vector_size (16)));
> +V a, b, c;
> +
> +void
> +foo ()
> +{
> + c = a > b ? a : b;
> +}
>
> Jakub
>
