[Bug tree-optimization/21705] New: FRE does not catch eliminate a redundant pute call.

["kazu at cs dot umass dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

Consider:

extern unsigned int strlen (const char *) __attribute__ ((__pure__));

void
foo (const char *str)
{
  unsigned int a = strlen (str);
  unsigned int b = strlen (str);
  if (a != b)
    link_error ();
}

FRE does not eliminate the second call to strlen.

-- 
           Summary: FRE does not catch eliminate a redundant pute call.
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kazu at cs dot umass dot edu
                CC: dberlin at gcc dot gnu dot org,gcc-bugs at gcc dot gnu
                    dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21705