[PATCH] D15408: [AArch64/LoopUnrollRuntime] Don't avoid high-cost trip count computation on the AArch64

Junmo Park via llvm-commits llvm-commits at lists.llvm.org
Tue Dec 15 16:42:55 PST 2015

flyingforyou added a comment.

Thanks for detailed experiment result, Kristof.

> Therefore, as is, I don't think the patch should be committed.

>  I'm wondering if there is any scope to make the AllowExpensiveTripCount heuristics smarter or more selective based on e.g. code characteristics?

>  Although the comments from James and Chad earlier indicate that that may need the compiler to guess very well how many iterations there are in inner loops, which is probably very hard without PGO information.

I agree with your opinon. so I will abandon this patch and upload new patch soon.



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