[Bug middle-end/29726] New: [4.2/4.3 regression] invalid folding of ((X >> C1) & C2) != 0 or "M-x is undefined" in emacs

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

fix for bug 21137 causes a regression:

/* { dg-do run } */
void abort (void);

int main (void)
{
  int k = -1;
  if (((unsigned int) k >> 3) & 134217728)
    return 0;
  abort ();
}

This bug is also known as miscompilation of emacs' keymap.c at -O0:
http://lists.gnu.org/archive/html/emacs-devel/2006-09/msg00276.html


-- 
           Summary: [4.2/4.3 regression] invalid folding of ((X >> C1) & C2)
                    != 0 or "M-x is undefined" in emacs
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: middle-end
        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=29726