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

[Ramkumar Ramachandra via llvm-commits]

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@@ -1101,7 +1106,7 @@ RecurrenceDescriptor::getReductionOpChain(PHINode *Phi, Loop *L) const {
     return nullptr;
   };
   auto isCorrectOpcode = [&](Instruction *Cur) {
-    if (RedOp == Instruction::ICmp || RedOp == Instruction::FCmp) {
+    if (!IsArithmetic) {
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artagnon wrote:

This function is called isCorrectOpcode(), and it doesn't check opcode anymore?

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