[PATCH] D19431: [LoopDist] Add llvm.loop.distribute.enable loop metadata

[Hal Finkel via llvm-commits]

hfinkel added a comment.

I have no problem with adding metadata to control this, just as we do with the vectorizer. However:

1. What is preventing us from enabling this pass by default?
2. Do we actually need to key it this way? Given that this metadata does not force anything, and is intended to enable vectorization, why not just key this off of !{!"llvm.loop.vectorize.enable", i1 1}. That way, should the user explicitly request vectorization, and we detect that this won't be possible, we try extra hard to provide it? That is, is there a use case where a user might want #pragma clang loop distribute(enable) without also adding vectorize(enable)?


http://reviews.llvm.org/D19431