[llvm] [InstCombine] Combine or-disjoint (and->mul), (and->mul) to and->mul (PR #136013)

[Matt Arsenault via llvm-commits]

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@@ -3560,6 +3560,72 @@ static Value *foldOrOfInversions(BinaryOperator &I,
   return nullptr;
 }
 
+struct DecomposedBitMaskMul {
+  Value *X;
+  APInt Factor;
+  APInt Mask;
+};
+
+static std::optional<DecomposedBitMaskMul> matchBitmaskMul(Value *V) {
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arsenm wrote:

This needs more documenting about what it does 

https://github.com/llvm/llvm-project/pull/136013