On Wed, 12 May 2021, Jakub Jelinek wrote:
> Hi!
>
> The inliner doesn't remap DEBUG_EXPR_DECLs, so the same decls can appear
> in multiple functions.
> Furthermore, expansion reuses corresponding DEBUG_EXPRs too, so they again
> can be reused in multiple functions.
> Neither of that is a major problem, DEBUG_EXPRs are just magic value holders
> and what value they stand for is independent in each function and driven by
> what debug stmts or DEBUG_INSNs they are bound to.
> Except for DEBUG_EXPR*s with vector types, TYPE_MODE can be either BLKmode
> or some vector mode depending on whether current function's enabled ISAs
> support that vector mode or not. On the following testcase, we expand it
> first in foo function without AVX2 enabled and so the DEBUG_EXPR is
> BLKmode, but later the same DEBUG_EXPR_DECL is used in a simd clone with
> AVX2 enabled and expansion ICEs because of a mode mismatch.
Ah, I wasn't aware we're doing this.
> The following patch fixes that by forcing recreation of a DEBUG_EXPR if
> there is a mode mismatch for vector typed DEBUG_EXPR_DECL, DEBUG_EXPRs
> will be still reused in between functions otherwise and within the same
> function the mode should be always the same.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK
Thanks,
Richard.
> 2021-05-11 Jakub Jelinek <ja...@redhat.com>
>
> PR middle-end/100508
> * cfgexpand.c (expand_debug_expr): For DEBUG_EXPR_DECL with vector
> type, don't reuse DECL_RTL if it has different mode, instead force
> creation of a new DEBUG_EXPR.
>
> * gcc.dg/gomp/pr100508.c: New test.
>
> --- gcc/cfgexpand.c.jj 2021-05-10 12:22:30.127455200 +0200
> +++ gcc/cfgexpand.c 2021-05-11 10:33:31.446450828 +0200
> @@ -4512,7 +4512,12 @@ expand_debug_expr (tree exp)
> op0 = DECL_RTL_IF_SET (exp);
>
> if (op0)
> - return op0;
> + {
> + if (GET_MODE (op0) != mode)
> + gcc_assert (VECTOR_TYPE_P (TREE_TYPE (exp)));
> + else
> + return op0;
> + }
>
> op0 = gen_rtx_DEBUG_EXPR (mode);
> DEBUG_EXPR_TREE_DECL (op0) = exp;
> --- gcc/testsuite/gcc.dg/gomp/pr100508.c.jj 2021-05-11 11:18:08.561067214
> +0200
> +++ gcc/testsuite/gcc.dg/gomp/pr100508.c 2021-05-11 11:17:39.520374736
> +0200
> @@ -0,0 +1,14 @@
> +/* PR middle-end/100508 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -g -fopenmp-simd" } */
> +
> +typedef int __attribute__((__vector_size__(32))) V;
> +V j;
> +
> +#pragma omp declare simd
> +int
> +foo (void)
> +{
> + V m = j;
> + return 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
