[InstCombine] fold icmp of the sum of ext bool based on limited range
For the pattern `(zext i1 X) + (sext i1 Y)`, the constant range is [-1, 1]. We can simplify the pattern by logical operations. Like: ``` (zext i1 X) + (sext i1 Y) == -1 --> ~X & Y (zext i1 X) + (sext i1 Y) == 0 --> ~(X ^ Y) (zext i1 X) + (sext i1 Y) == 1 --> X & ~Y ``` And other predicates can the combination of these results: ``` (zext i1 X) + (sext i1 Y)) != -1 --> X | ~Y (zext i1 X) + (sext i1 Y)) s> -1 --> X | ~Y (zext i1 X) + (sext i1 Y)) u< -1 --> X | ~Y (zext i1 X) + (sext i1 Y)) s> 0 --> X & ~Y (zext i1 X) + (sext i1 Y)) s< 0 --> ~X & Y (zext i1 X) + (sext i1 Y)) != 1 --> ~X | Y (zext i1 X) + (sext i1 Y)) s< 1 --> ~X | Y (zext i1 X) + (sext i1 Y)) u> 1 --> ~X & Y ``` All alive proofs: https://alive2.llvm.org/ce/z/KmgDpF https://alive2.llvm.org/ce/z/fLwWa9 https://alive2.llvm.org/ce/z/ZKQn2P Fix: https://github.com/llvm/llvm-project/issues/59666 Reviewed By: spatel Differential Revision: https://reviews.llvm.org/D143373
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