[PATCH] D43256: [MBP] Move a latch block with conditional exit and multi predecessors to top of loop

[Guozhi Wei via Phabricator via llvm-commits]

Carrot added a comment.

@GalZohar, without a testcase I can't say what's the problem.

It is not intentional to increase the number of branches of any particular path. All of the algorithms are driven by branch probabilities. If you didn't collect profiling, llvm guesses a probability for each branch, it's reasonable for most code. But it's not rare that the guessed probability is different from actual probability, it may not result in a good layout.

So I strongly suggest you try profiling build. MBP is one of the passes that get most performance improvement from profiling.


Repository:
  rL LLVM

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  https://reviews.llvm.org/D43256/new/

https://reviews.llvm.org/D43256