[PATCH] D124763: [InstCombine] Fold A + (B & ~A) to A | B

[Nikita Popov via Phabricator via llvm-commits]

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This adds two folds:

- `A + (B & ~A)` --> `A | B` (https://alive2.llvm.org/ce/z/N5fWZ9)
- `A + ((A & B) ^ B)` (https://alive2.llvm.org/ce/z/so3jNz)

The reason why the second fold is necessary is that we consider this to be the canonical form if `B` is a constant. (I did check whether we can change that, but it looks like a number of folds depend on the current canonicalization, so I ended up adding both patterns here.)


https://reviews.llvm.org/D124763

Files:
  llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
  llvm/test/Transforms/InstCombine/add.ll

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