[all-commits] [llvm/llvm-project] 70aca7: [InstCombine] Explicitly track dead edges

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 70aca7b12220971dcc54ec6431813665eac5856e
      https://github.com/llvm/llvm-project/commit/70aca7b12220971dcc54ec6431813665eac5856e
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2023-07-27 (Thu, 27 Jul 2023)

  Changed paths:
    M llvm/include/llvm/Transforms/InstCombine/InstCombiner.h
    M llvm/lib/Transforms/InstCombine/InstCombineInternal.h
    M llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
    M llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
    M llvm/test/Transforms/InstCombine/unreachable-code.ll

  Log Message:
  -----------
  [InstCombine] Explicitly track dead edges

This allows us to handle dead blocks with multiple incoming edges,
where we can determine that all of those edges are dead (or cycles).

This allows InstCombine to handle certain dead code patterns that
can be produced by LoopVectorize in a single iteration.

This is in preparation for D154579.