[Bug middle-end/19807] New: fold does not fold &a[4]-1

[rguenth at gcc dot gnu dot org]

PR19639 is pessimized by (?)

extern void link_error(void);
int main(void)
{
  int a[4];
  if (&a[2]-1 != &a[1])
    link_error();
  return 0;
}

where for C++ (!!) we do not fold the addition of ADDR_EXPR (ARRAY_REF (..))
 and INTEGER_CST into the ARRAY_REF offset.  For C the frontend avoids
passing ARRAY_REFs to fold.

-- 
           Summary: fold does not fold &a[4]-1
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
OtherBugsDependingO 19639
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19807