[all-commits] [llvm/llvm-project] 2aa471: [InstCombine] remove zext-of-icmp fold that may co...

[Sanjay Patel via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2aa471bd92dfd9a682e1287840a4ced5d9f36c84
      https://github.com/llvm/llvm-project/commit/2aa471bd92dfd9a682e1287840a4ced5d9f36c84
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2023-01-10 (Tue, 10 Jan 2023)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
    M llvm/test/Transforms/InstCombine/zext.ll

  Log Message:
  -----------
  [InstCombine] remove zext-of-icmp fold that may conflict with other folds

This bit-hack transform would cause the new test to infinite loop
after 21d3871b7c90f85b3ae.

The deleted transform has existed for a very long time,
but the profitable parts appear to be handled by other
folds now. This fold could replace 2 instructions with
4 instructions, so it was always in danger of going
overboard.

No tests regress by removing the whole thing.