On Fri, 17 Jan 2025, Jakub Jelinek wrote:
> Hi!
>
> The last case of this optimization assumes that if 2 integral types
> have same precision and TYPE_UNSIGNED, then they are uselessly convertible.
> While that is very likely the case for GIMPLE, it is not the case for
> GENERIC, so the following patch adds there a convert so that the
> optimization produces also valid GENERIC. Without it we got
> (int) p == b where b had _BitInt(32) type, so incompatible types.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
> 2025-01-17 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/118522
> * match.pd ((FTYPE) N CMP (FTYPE) M): Add convert, as in GENERIC
> integral types with the same precision and sign might actually not
> be compatible types.
>
> * gcc.dg/bitint-120.c: New test.
>
> --- gcc/match.pd.jj 2025-01-16 09:09:06.000000000 +0100
> +++ gcc/match.pd 2025-01-16 19:24:16.838305254 +0100
> @@ -7253,7 +7253,7 @@ (define_operator_list SYNC_FETCH_AND_AND
> (icmp (convert:type2 @1) @2)
> (if (TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
> && type1_signed_p == type2_signed_p)
> - (icmp @1 @2))))))))))
> + (icmp @1 (convert @2)))))))))))
>
> /* Optimize various special cases of (FTYPE) N CMP CST. */
> (for cmp (lt le eq ne ge gt)
> --- gcc/testsuite/gcc.dg/bitint-120.c.jj 2025-01-16 19:30:14.816518100
> +0100
> +++ gcc/testsuite/gcc.dg/bitint-120.c 2025-01-16 19:29:56.429763982 +0100
> @@ -0,0 +1,11 @@
> +/* PR tree-optimization/118522 */
> +/* { dg-do compile { target bitint } } */
> +/* { dg-options "-O2" } */
> +
> +_BitInt(32) b;
> +
> +int
> +foo (unsigned short p)
> +{
> + return p == (double) b;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
