On Fri, Jan 17, 2014 at 2:37 PM, Marek Polacek <pola...@redhat.com> wrote:
> This is the real fix for PR58346. I'd say the easiest solution is
> just not fold the zero-sized elements.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
Ok.
Thanks,
Richard.
> 2014-01-17 Marek Polacek <pola...@redhat.com>
>
> PR c/58346
> * gimple-fold.c (fold_array_ctor_reference): Don't fold if element
> size is zero.
> testsuite/
> * gcc.dg/pr58346.c: New test.
>
> --- gcc/gimple-fold.c.mp2 2014-01-17 12:03:56.149446880 +0100
> +++ gcc/gimple-fold.c 2014-01-17 12:04:00.450462677 +0100
> @@ -2940,7 +2940,8 @@ fold_array_ctor_reference (tree type, tr
> be larger than size of array element. */
> if (!TYPE_SIZE_UNIT (type)
> || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
> - || elt_size.slt (tree_to_double_int (TYPE_SIZE_UNIT (type))))
> + || elt_size.slt (tree_to_double_int (TYPE_SIZE_UNIT (type)))
> + || elt_size.is_zero ())
> return NULL_TREE;
>
> /* Compute the array index we look for. */
> --- gcc/testsuite/gcc.dg/pr58346.c.mp2 2014-01-17 12:27:26.180127058 +0100
> +++ gcc/testsuite/gcc.dg/pr58346.c 2014-01-17 12:28:20.466332046 +0100
> @@ -0,0 +1,19 @@
> +/* PR tree-optimization/58346 */
> +/* { dg-do compile } */
> +/* { dg-options "-O" } */
> +
> +struct U {};
> +static struct U b[1] = { };
> +extern void bar (struct U);
> +
> +void
> +foo (void)
> +{
> + bar (b[0]);
> +}
> +
> +void
> +baz (void)
> +{
> + foo ();
> +}
>
> Marek
