On Thu, 17 Oct 2019, Jakub Jelinek wrote:
> Hi!
>
> The following bug has been introduced when cond_expr_object_size has been
> added in 2007. We want to treat a COND_EXPR like a PHI with 2 arguments,
> and PHI is handled in a loop that breaks if the lhs value is unknown, and
> then does the if (TREE_CODE (arg) == SSA_NAME) merge_object_sizes else
> expr_object_size which is used even in places that handle just a single
> operand (with the lhs value initialized to the opposite value of unknown
> first). At least expr_object_size asserts that the lhs value is not
> unknown at the start.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> trunk?
OK.
> 2019-10-17 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/92056
> * tree-object-size.c (cond_expr_object_size): Return early if then_
> processing resulted in unknown size.
>
> * gcc.c-torture/compile/pr92056.c: New test.
>
> --- gcc/tree-object-size.c.jj 2019-10-05 09:35:14.895967464 +0200
> +++ gcc/tree-object-size.c 2019-10-16 15:34:11.414769994 +0200
> @@ -903,6 +903,9 @@ cond_expr_object_size (struct object_siz
> else
> expr_object_size (osi, var, then_);
>
> + if (object_sizes[object_size_type][varno] == unknown[object_size_type])
> + return reexamine;
> +
> if (TREE_CODE (else_) == SSA_NAME)
> reexamine |= merge_object_sizes (osi, var, else_, 0);
> else
> --- gcc/testsuite/gcc.c-torture/compile/pr92056.c.jj 2019-10-16
> 15:42:56.042848440 +0200
> +++ gcc/testsuite/gcc.c-torture/compile/pr92056.c 2019-10-16
> 15:42:41.595066602 +0200
> @@ -0,0 +1,18 @@
> +/* PR tree-optimization/92056 */
> +
> +const char *d;
> +
> +void
> +foo (int c, char *e, const char *a, const char *b)
> +{
> + switch (c)
> + {
> + case 33:
> + for (;; d++)
> + if (__builtin_strcmp (b ? : "", d))
> + return;
> + break;
> + case 4:
> + __builtin_sprintf (e, a);
> + }
> +}
>
> Jakub
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
