[PATCH] D21299: [Codegen Prepare] Swap commutative binops before splitting branch condition.

[Tim Northover via llvm-commits]

t.p.northover added a comment.

Yuck, I hate heuristics like this. It's not even particularly clear that "range size" correlates well with probability in real code, let alone with what any given branch predictor thinks of that probability.

When you remove the 'mcf' test that this patch was specifically written to target, it turns into a net regression on geomean even on Kryo. I'm not entirely sure how fair that is (I avoided statistics like the plague), but isn't using separate data to derive and test code/hypotheses generally considered a good thing?


http://reviews.llvm.org/D21299