[Bug tree-optimization/21449] New: Loop unroller is way over estimating the unroll size of a loop

["pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

The loop unroller over estimates the unrolled sized of an empty loop:
int f(void)
{
int i;
for(i = 0 ;i < 10; i++);
}

We get:
  Loop size: 5
  Estimated size after unrolling: 10

-- 
           Summary: Loop unroller is way over estimating the unroll size of
                    a loop
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, TREE
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21449