[Bug tree-optimization/33434] New: [4.3 Regression] -fipa-cp miscompilation

["belyshev at depni dot sinp dot msu dot ru" <gcc-bugzilla at gcc dot gnu dot org>]

Found this while trying to bootstrap with BOOT_CFLAGS="-O3 -fipa-cp" and it
miscompiled libcpp/macro.c at the stage2.  Appeared somewhere in between
r122374 and r124593:

/* { dg-do run } */
/* { dg-options "-O3 -fipa-cp" } */

int k;

void f1 (int a, int b)
{
  if (a)
    while (b --)
      k = 1;
  else
    if (b != 1)
      __builtin_abort ();
}

int main (void)
{
  f1 (1, 1);
  if (k != 1)
    __builtin_abort ();
  return 0;
}


-- 
           Summary: [4.3 Regression] -fipa-cp miscompilation
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: belyshev at depni dot sinp dot msu dot ru


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33434