[llvm] [LV] Bundle sub reductions into VPExpressionRecipe (PR #147255)

[Sander de Smalen via llvm-commits]

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@@ -3126,14 +3127,15 @@ tryToMatchAndCreateMulAccumulateReduction(VPReductionRecipe *Red,
   };
 
   VPValue *VecOp = Red->getVecOp();
+  VPValue *Mul = VecOp;
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sdesmalen-arm wrote:

This looks like a partially NFC change, and I'd prefer the use of `VecOp` as it was before this change. The reason for this is that in the case that `VecOp` is not a multiply, `Mul` is still defined (to the value of `VecOp`), which I don't think is right.

https://github.com/llvm/llvm-project/pull/147255