[llvm] [VPlan] Sink retrieving legacy costs to more specific computeCost impls. (PR #109708)

[Florian Hahn via llvm-commits]

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@@ -274,33 +274,28 @@ void VPRecipeBase::moveBefore(VPBasicBlock &BB,
   insertBefore(BB, I);
 }
 
-/// Return the underlying instruction to be used for computing \p R's cost via
-/// the legacy cost model. Return nullptr if there's no suitable instruction.
-static Instruction *getInstructionForCost(const VPRecipeBase *R) {
-  if (auto *S = dyn_cast<VPSingleDefRecipe>(R))
-    return dyn_cast_or_null<Instruction>(S->getUnderlyingValue());
-  if (auto *IG = dyn_cast<VPInterleaveRecipe>(R))
-    return IG->getInsertPos();
-  // Currently the legacy cost model only calculates the instruction cost with
-  // underlying instruction. Removing the WidenMem here will prevent
-  // force-target-instruction-cost overwriting the cost of recipe with
-  // underlying instruction which is inconsistent with the legacy model.
-  // TODO: Remove WidenMem from this function when we don't need to compare to
-  // the legacy model.
-  if (auto *WidenMem = dyn_cast<VPWidenMemoryRecipe>(R))
-    return &WidenMem->getIngredient();
-  return nullptr;
-}
-
 InstructionCost VPRecipeBase::cost(ElementCount VF, VPCostContext &Ctx) {
-  auto *UI = getInstructionForCost(this);
-  if (UI && Ctx.skipCostComputation(UI, VF.isVector()))
-    return 0;
-
-  InstructionCost RecipeCost = computeCost(VF, Ctx);
-  if (UI && ForceTargetInstructionCost.getNumOccurrences() > 0 &&
-      RecipeCost.isValid())
-    RecipeCost = InstructionCost(ForceTargetInstructionCost);
+  // Get the underlying instruction for the recipe, if there is one. Is is used
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fhahn wrote:

Fixed, thanks!

https://github.com/llvm/llvm-project/pull/109708