[PATCH] D87034: [KnownBits] Implement accurate unsigned and signed max and min

Mon Sep 7 13:27:37 PDT 2020

nikic added a comment.

Contrary to my expectations, this change had a small but measurable compile-time impact: https://llvm-compile-time-tracker.com/compare.php?from=04ea680a8ccc4f9a4d7333cd712333960348c35b&to=5350e1b5096aa4707aa525baf7398d93b4a4f1a5&stat=instructions

Unfortunately, I have no idea why. I looked at callgrind profiles and the extra instructions (consistently) end up inside a DenseMap method (without changes to number of calls). Can't explain why that would happen, and the diff is not large enough to bother looking further.

I did end up applying this small cleanup while looking over the code again: https://github.com/llvm/llvm-project/commit/ddab4cd83ea31141aaada424dccf94278482ee88

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87034/new/

https://reviews.llvm.org/D87034