[Bug tree-optimization/34363] [4.2 Regression] Aliasing failure during tree fre

["sandra at codesourcery dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #5 from sandra at codesourcery dot com  2008-04-30 20:17 -------
Here's another testcase for the same bug, or one closely related to it:

#include <stdio.h>
unsigned x = 8;
unsigned *addr()
{
  return &x;
}
int main()
{
  x = 4;
  *addr() = *addr() / 2;
  printf ("*addr() = %d, x = %d\n", *addr(), x);
  return 0;
}

I've determined that both this test case and the original one reported with
this issue were fixed on mainline by the commit r119502, this patch:

http://gcc.gnu.org/ml/gcc-patches/2006-12/msg00225.html

I'm not familiar enough with this code (yet!) to be able to tell whether this
was a lurking bug fixed by that patch, or whether it is a lurking bug that was
merely obscured by that patch and is still present on mainline.


-- 

sandra at codesourcery dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sandra at codesourcery dot
                   |                            |com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34363