[Bug tree-optimization/34265] Missed optimizations

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2007-11-28 16:06 -------
GCC doesn't have a facility to split the inner loop and move it out of the
outer loops by introducing a array temporary.

As for completely unrolling, this only happens for innermost loops(?) and you
can tune the heuristics with --param max-completely-peeled-insns=N (defaults to
400) and --param max-completely-peel-times (defaults to 16).  Use
-funroll-loops
to enable this.

Note that complete unrolling happens too late to help LIM or vectorization.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34265