[PATCH] D22639: Add flag to PassManagerBuilder to disable GVN Hoist Pass.

[Benjamin Kramer via llvm-commits]

bkramer added a subscriber: bkramer.
bkramer added a comment.

The problem is not a Halide test but a scalability issue in MemorySSA that's making Halide unusable, consuming gigabytes of memory and taking forever. Personally, I don't think the GVNHoist pass is ready for prime time yet and needs more testing, like we did for other passes that were first rigorously tested under a flag before being enabled by default. Going directly from zero to default with a major new optimization infrastructure (MemSSA) is a recipe for disaster.

Sadly the test case is fairly large and being a compile time regression reduction is difficult, I believe Alina is working on that.


https://reviews.llvm.org/D22639