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