[llvm] [ValueTracking] Add `matchSimpleBinaryIntrinsicRecurrence` helper (PR #145964)

[Antonio Frighetto via llvm-commits]

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@@ -965,6 +966,21 @@ LLVM_ABI bool matchSimpleRecurrence(const PHINode *P, BinaryOperator *&BO,
 LLVM_ABI bool matchSimpleRecurrence(const BinaryOperator *I, PHINode *&P,
                                     Value *&Start, Value *&Step);
 
+/// Attempt to match a simple value-accumulating recurrence of the form:
+///   %llvm.intrinsic.acc = phi Ty [%Init, %Entry], [%llvm.intrinsic, %backedge]
+///   %llvm.intrinsic = call Ty @llvm.intrinsic(%Invariant, %llvm.intrinsic.acc)
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antoniofrighetto wrote:

Right, was mentioned in the doc-comment, but the variable name didn't reflect this; updated, thanks!

https://github.com/llvm/llvm-project/pull/145964