[all-commits] [llvm/llvm-project] 5d7d2f: [InstCombine] improve efficiency of isFreeToInvert

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  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5d7d2f0d2e7b137e68337b0b472130b61d9f305e
      https://github.com/llvm/llvm-project/commit/5d7d2f0d2e7b137e68337b0b472130b61d9f305e
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-08-23 (Mon, 23 Aug 2021)

  Changed paths:
    M llvm/include/llvm/Transforms/InstCombine/InstCombiner.h

  Log Message:
  -----------
  [InstCombine] improve efficiency of isFreeToInvert

This is NFC-intended when viewed from outside the pass.
I was trying to make sure that we don't infinite loop
in subtract combines and noticed that we handle the
non-canonical forms of add/sub here, but it should
not be necessary. Coding it this way seems slightly
clearer than mixing all 4 patterns as before.