[llvm] [IVDescriptors][NFC] Refactor getReductionOpChain to remove the dependency of non-arithmetic reductions on getOpcode. (PR #118777)

[Mel Chen via llvm-commits]

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@@ -1110,7 +1115,7 @@ RecurrenceDescriptor::getReductionOpChain(PHINode *Phi, Loop *L) const {
     if (isFMulAddIntrinsic(Cur))
       return true;
 
-    return Cur->getOpcode() == RedOp;
+    return Cur->getOpcode() == getOpcode();
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Mel-Chen wrote:

Only arithmetic reductions call getOpcode and check the opcode, non-arithmetic won't reach     this check statement.

https://github.com/llvm/llvm-project/pull/118777