Loop distribution (from the patch http://gcc.gnu.org/ml/gcc-patches/2007-12/msg00215.html) fails to distribute the following loop:
for (i = 2; i <= n; ++i) { a[i] += c[i] * d[i]; b[i] = a[i] + d[i] + b[i - 1]; } dumping "FIXME: Loop 1 not distributed: failed to build the RDG." (After distribution the first loop will be vectorizable). -- Summary: Loop distribution fails to distribute Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: enhancement Priority: P3 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: irar at il dot ibm dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35272