[llvm] [VPlan] Add cost for `VPWidenMemoryRecipe` (PR #105614)

[Florian Hahn via llvm-commits]

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@@ -2084,6 +2084,37 @@ void VPPredInstPHIRecipe::print(raw_ostream &O, const Twine &Indent,
 }
 #endif
 
+InstructionCost VPWidenMemoryRecipe::computeCost(ElementCount VF,
+                                                 VPCostContext &Ctx) const {
+  Instruction *I = getInstructionForCost(this);
+  Type *Ty = ToVectorTy(getElementType(), VF);
+  const Align Alignment = getLoadStoreAlignment(const_cast<Instruction *>(I));
+  const Value *Ptr = getLoadStorePointerOperand(I);
+  unsigned AS = getLoadStoreAddressSpace(const_cast<Instruction *>(I));
+  TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput;
+
+  if (Consecutive) {
+    InstructionCost Cost = 0;
+    if (IsMasked) {
+      Cost += Ctx.TTI.getMaskedMemoryOpCost(I->getOpcode(), Ty, Alignment, AS,
+                                            CostKind);
+    } else {
+      TTI::OperandValueInfo OpInfo = Ctx.TTI.getOperandInfo(I->getOperand(0));
+      Cost += Ctx.TTI.getMemoryOpCost(I->getOpcode(), Ty, Alignment, AS,
+                                      CostKind, OpInfo, I);
+    }
+    if (Reverse)
+      Cost += Ctx.TTI.getShuffleCost(TargetTransformInfo::SK_Reverse,
+                                     cast<VectorType>(Ty), std::nullopt,
+                                     CostKind, 0);
+
+    return Cost;
+  }
+  return Ctx.TTI.getAddressComputationCost(Ty) +
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fhahn wrote:

maybe handle the simpler case `(!Consecutive)` first with an early return?

https://github.com/llvm/llvm-project/pull/105614