On Mon, Feb 03, 2014 at 03:18:49PM -0800, Richard Henderson wrote:
> The problem with this pr is that the -uninit pass could get itself
> into a loop while processing nodes. Within this loop, it would
> allocate memory, therefore the visible symptom was allocation
> failure instead of a non-terminating loop.
>
> Amusingly, the case that prods the -uninit pass into this behaviour
> contains an uninitialized variable.
Thanks.
> I briefly tried to produce a reduced test case, but didn't manage
> to do so. The one in the PR is a bit big to commit...
I've committed a testcase for this, delta can do wonders :)
2014-02-04 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/59924
* gcc.dg/pr59924.c: New test.
--- gcc/testsuite/gcc.dg/pr59924.c.jj 2014-02-04 01:42:43.691929830 +0100
+++ gcc/testsuite/gcc.dg/pr59924.c 2014-02-04 01:42:24.000000000 +0100
@@ -0,0 +1,27 @@
+/* PR tree-optimization/59924 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -Wall" } */
+
+struct S { struct T *a; double b; struct S *c; };
+struct T { struct S *d; };
+extern void bar (double);
+
+void
+foo (struct S * x, int y, int z, int w)
+{
+ int e;
+ struct S *f;
+ for (f = x->a->d; f; f = f->c)
+ {
+ if (5 < w)
+ {
+ e = -w;
+ z = w;
+ }
+ }
+ if (y != 0 || z != 0)
+ {
+ double g = x->b + (double) e * (double) y; /* { dg-warning "may be used
uninitialized in this function" } */
+ bar (g * g);
+ }
+}
Jakub
