On Fri, 12 Jan 2024, Jakub Jelinek wrote:
> Hi!
>
> This is the case I was talking about in
> https://gcc.gnu.org/pipermail/gcc-patches/2024-January/642423.html
> and Zdenek kindly found a testcase for it.
> We can only create BITINT_TYPE with precision at most 65535, not 65536,
> so need to punt if we'd want to create it.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK
> 2024-01-12 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/113330
> * tree-sra.cc (create_access): Punt for BITINT_TYPE accesses with
> too large size.
>
> * gcc.dg/bitint-69.c: New test.
>
> --- gcc/tree-sra.cc.jj 2024-01-10 12:45:54.293851670 +0100
> +++ gcc/tree-sra.cc 2024-01-11 15:13:29.697073438 +0100
> @@ -967,6 +967,12 @@ create_access (tree expr, gimple *stmt,
> disqualify_candidate (base, "Encountered an access beyond the base.");
> return NULL;
> }
> + if (TREE_CODE (TREE_TYPE (expr)) == BITINT_TYPE
> + && size > WIDE_INT_MAX_PRECISION - 1)
> + {
> + disqualify_candidate (base, "Encountered too large _BitInt access.");
> + return NULL;
> + }
>
> access = create_access_1 (base, offset, size);
> access->expr = expr;
> --- gcc/testsuite/gcc.dg/bitint-69.c.jj 2024-01-11 15:16:57.573140907
> +0100
> +++ gcc/testsuite/gcc.dg/bitint-69.c 2024-01-12 09:55:30.026374627 +0100
> @@ -0,0 +1,25 @@
> +/* PR tree-optimization/113330 */
> +/* { dg-do compile { target bitint } } */
> +/* { dg-require-stack-check "generic" } */
> +/* { dg-options "-std=c23 -O --param=large-stack-frame=131072
> -fstack-check=generic --param=sccvn-max-alias-queries-per-access=0" } */
> +
> +_BitInt(8) a;
> +
> +static inline __attribute__((__always_inline__)) void
> +bar (int, int, int, int, int, int, int, int)
> +{
> +#if __BITINT_MAXWIDTH__ >= 65535
> + _BitInt(65535) b = 0;
> + _BitInt(383) c = 0;
> +#else
> + _BitInt(63) b = 0;
> + _BitInt(39) c = 0;
> +#endif
> + a = b;
> +}
> +
> +void
> +foo (void)
> +{
> + bar (0, 0, 0, 0, 0, 0, 0, 0);
> +}
>
> 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)
