[all-commits] [llvm/llvm-project] 444f08: [InstCombine] fold icmp of truncated left shift, p...

[Sanjay Patel via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 444f08c832c8ba67ad595037b58e3ac616a756f1
      https://github.com/llvm/llvm-project/commit/444f08c832c8ba67ad595037b58e3ac616a756f1
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2022-09-08 (Thu, 08 Sep 2022)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
    M llvm/test/Transforms/InstCombine/icmp-trunc.ll

  Log Message:
  -----------
  [InstCombine] fold icmp of truncated left shift, part 2

(trunc (1 << Y) to iN) == 2**C --> Y == C
(trunc (1 << Y) to iN) != 2**C --> Y != C
https://alive2.llvm.org/ce/z/xnFPo5

Follow-up to d9e1f9d7591b0d3e4d. This was a suggested
enhancement mentioned in issue #51889.