[Bug tree-optimization/18316] New: Missed IV optimization

[steven at gcc dot gnu dot org]

The following test case from Briggs' optimization test suite is 
missed by tree IV opts (and nothing on RTL catches this either): 
 
void 
strength_test2(int *data) 
{ 
  int k = data[0]; 
  int i = 0; 
  do { 
    data[data[2]] = 2; 
    i = i + 1; 
  } while (i * k < data[1]); 
} 
 
void 
strength_result2(int *data) 
{ 
  int k = data[0]; 
  int i = 0; 
  do { 
    data[data[2]] = 2; 
    i = i + k; 
  } while (i < data[1]); 
}

-- 
           Summary: Missed IV optimization
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: rakdver at gcc dot gnu dot org
        ReportedBy: steven at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18316