[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.10.22 12:25:43
     Ever Confirmed|0                           |1

--- Comment #10 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-10-22 
12:25:43 UTC ---
Peeling for alignment needs adjustment:

float val[256];
float x;
void __attribute__((noinline,noclone))
foo(int len, int beg)
{
  int i;
  for (i = len - 1; i >= beg; --i)
    x += val[i] * 2;
}
int main()
{
  foo(256-3, 0);
  return 0;
}

segfaults.  We align &val[len-1] instead of &val[len-4].