[llvm] [VPlan] Change parent of VPReductionRecipe to VPRecipeWithIRFlags. NFC (PR #130881)

[Elvis Wang via llvm-commits]

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@@ -2296,29 +2304,34 @@ class VPReductionRecipe : public VPSingleDefRecipe {
 protected:
   VPReductionRecipe(const unsigned char SC, const RecurrenceDescriptor &R,
                     Instruction *I, ArrayRef<VPValue *> Operands,
-                    VPValue *CondOp, bool IsOrdered, DebugLoc DL)
-      : VPSingleDefRecipe(SC, Operands, I, DL), RdxDesc(R),
+                    VPValue *CondOp, bool IsOrdered)
+      : VPRecipeWithIRFlags(SC, Operands, *I), RdxDesc(R),
         IsOrdered(IsOrdered) {
     if (CondOp) {
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ElvisWang123 wrote:

No, we cannot construct VPReductionRecipe without underlying value at least for now. 

1. In VPRecipeBase::cost(), `forceTargetInstructionCost` and `skipCostComputation` will check if the  recipe contains underlying instruction and override/skip the cost of the recipe. 

I think is better to set the flag directly after the #113903 landed and a better logic to override the cost from `forceTargetInstructionCost`. 

https://github.com/llvm/llvm-project/pull/130881