[PATCH] D133275: [SimpleLoopUnswitch] Skip non-trivial unswitching of cold functions

[Teresa Johnson via Phabricator via llvm-commits]

tejohnson added a comment.

This patch is provoking some extreme compile time when we have a large cold function with many loop nests, since it repeatedly reanalyzes the coldness of the entire function, which involves walking all BBs (and all instructions in the case of SamplePGO). Based on the example given in D129599 <https://reviews.llvm.org/D129599> for the SPEC degradation, we should only need to check all loops in the loop nest, not the entire function. I mailed D146383 <https://reviews.llvm.org/D146383> with that fix.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D133275/new/

https://reviews.llvm.org/D133275