On Fri, Oct 4, 2024 at 12:12 PM Jakub Jelinek <ja...@redhat.com> wrote:
>
> Hi!
>
> The following testcase ICEs, because the ix86_expand_int_compare
> optimization to use {,v}ptest assumes there are instructions for all
> 16-byte vector modes. That isn't the case, we only have one for
> V16QI, V8HI, V4SI, V2DI, V1TI, V4SF and V2DF, not for
> V8HF nor V8BF.
>
> The following patch fixes that by using the V8HI instruction instead
> for those 2 modes. tmp can't be a SUBREG, because it is SUBREG_REG
> of another SUBREG, so we don't need to worry about gen_lowpart
> failing.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2024-10-04 Jakub Jelinek <ja...@redhat.com>
>
> PR target/116921
> * config/i386/i386-expand.cc (ix86_expand_int_compare): Add a SUBREG
> to V8HImode from V8HFmode or V8BFmode before generating a ptest.
>
> * gcc.target/i386/pr116921.c: New test.
OK.
Thanks,
Uros.
>
> --- gcc/config/i386/i386-expand.cc.jj 2024-10-03 17:27:28.328227793 +0200
> +++ gcc/config/i386/i386-expand.cc 2024-10-03 18:11:18.514076904 +0200
> @@ -3095,6 +3095,9 @@ ix86_expand_int_compare (enum rtx_code c
> && GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))) == 16)
> {
> tmp = SUBREG_REG (op0);
> + if (GET_MODE_INNER (GET_MODE (tmp)) == HFmode
> + || GET_MODE_INNER (GET_MODE (tmp)) == BFmode)
> + tmp = gen_lowpart (V8HImode, tmp);
> tmp = gen_rtx_UNSPEC (CCZmode, gen_rtvec (2, tmp, tmp), UNSPEC_PTEST);
> }
> else
> --- gcc/testsuite/gcc.target/i386/pr116921.c.jj 2024-10-03 18:16:36.368711747
> +0200
> +++ gcc/testsuite/gcc.target/i386/pr116921.c 2024-10-03 18:17:25.702034243
> +0200
> @@ -0,0 +1,12 @@
> +/* PR target/116921 */
> +/* { dg-do compile { target int128 } } */
> +/* { dg-options "-O2 -msse4" } */
> +
> +long x;
> +_Float16 __attribute__((__vector_size__ (16))) f;
> +
> +void
> +foo (void)
> +{
> + x -= !(__int128) (f / 2);
> +}
>
> Jakub
>
