[all-commits] [llvm/llvm-project] 5de89b: [ValueTracking] Support non-zero pow2 for shl with...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5de89b4d99c913e3c7c2735886f2519a2ed39d8a
      https://github.com/llvm/llvm-project/commit/5de89b4d99c913e3c7c2735886f2519a2ed39d8a
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2023-08-07 (Mon, 07 Aug 2023)

  Changed paths:
    M llvm/lib/Analysis/ValueTracking.cpp
    M llvm/test/Transforms/InstCombine/icmp.ll

  Log Message:
  -----------
  [ValueTracking] Support non-zero pow2 for shl with nowrap flags

If the shl has either nuw or nsw flags, then we know that bits
cannot be shifted out, so a power of two cannot become zero.

Proofs: https://alive2.llvm.org/ce/z/4QfebE