[llvm] [VPlan] Extract reverse operation for reverse accesses (PR #146525)

[Mel Chen via llvm-commits]

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@@ -1147,6 +1150,13 @@ InstructionCost VPInstruction::computeCost(ElementCount VF,
                                   I32Ty, {Arg0Ty, I32Ty, I1Ty});
     return Ctx.TTI.getIntrinsicInstrCost(Attrs, Ctx.CostKind);
   }
+  case VPInstruction::Reverse: {
+    assert(VF.isVector() && "Reverse operation must be vector type");
+    Type *VectorTy = toVectorTy(Ctx.Types.inferScalarType(getOperand(0)), VF);
+    return Ctx.TTI.getShuffleCost(
+        TargetTransformInfo::SK_Reverse, cast<VectorType>(VectorTy),
+        cast<VectorType>(VectorTy), {}, Ctx.CostKind, 0);
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Mel-Chen wrote:

Sure.
5d402e2dd899ecf2105eb79ede4c811d3634286f

https://github.com/llvm/llvm-project/pull/146525