http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55334
--- Comment #19 from Richard Biener <rguenth at gcc dot gnu.org> 2012-12-21 14:08:24 UTC --- Btw, one thing to improve would be the excessive number of aliasing runtime checks the vectorizer currently generates. That would also help himeno. What is missing here is conservative merging of tests (thus making them slightly less precise for the sake of reducing their number). We create different tests for, say, R vs. U(I1, I2, I3) and R vs. U(I1-1,I2, I3). It's of course not that trivial, otherwise somebody would have done it already (see vect_prune_runtime_alias_test_list - we only merge equal range tests and do not try to use a convex hull to cover multiple tests with one).
