Rebase and address review

Author: SamTebbs33

llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp

@@ -2869,15 +2869,16 @@ InstructionCost VPExpressionRecipe::computeCost(ElementCount VF,
     unsigned Opcode = RecurrenceDescriptor::getOpcode(
         cast<VPReductionRecipe>(ExpressionRecipes[1])->getRecurrenceKind());
     auto *ExtR = cast<VPWidenCastRecipe>(ExpressionRecipes[0]);
-    if (isa<VPPartialReductionRecipe>(ExpressionRecipes.back())) {
-      return Ctx.TTI.getPartialReductionCost(
-          Opcode, Ctx.Types.inferScalarType(getOperand(0)), nullptr, RedTy, VF,
-          TargetTransformInfo::getPartialReductionExtendKind(ExtR->getOpcode()),
-          TargetTransformInfo::PR_None, std::nullopt, Ctx.CostKind);
-    }
-    return Ctx.TTI.getExtendedReductionCost(
-        Opcode, ExtR->getOpcode() == Instruction::ZExt, RedTy, SrcVecTy,
-        std::nullopt, Ctx.CostKind);
+    return isa<VPPartialReductionRecipe>(ExpressionRecipes.back())
+               ? Ctx.TTI.getPartialReductionCost(
+                     Opcode, Ctx.Types.inferScalarType(getOperand(0)), nullptr,
+                     RedTy, VF,
+                     TargetTransformInfo::getPartialReductionExtendKind(
+                         ExtR->getOpcode()),
+                     TargetTransformInfo::PR_None, std::nullopt, Ctx.CostKind)
+               : Ctx.TTI.getExtendedReductionCost(
+                     Opcode, ExtR->getOpcode() == Instruction::ZExt, RedTy,
+                     SrcVecTy, std::nullopt, Ctx.CostKind);
   }
   case ExpressionTypes::MulAccReduction:
     return Ctx.TTI.getMulAccReductionCost(false, Opcode, RedTy, SrcVecTy,

llvm/test/Transforms/LoopVectorize/AArch64/partial-reduce-constant-ops.ll

@@ -538,7 +538,7 @@ loop:
   %mul = mul i32 %conv, %conv
   %mul.ext = zext i32 %mul to i64
   %add = add i64 %res2, %mul.ext
-  %or = or i32 %mul, %c
+  %second_use = or i32 %mul, %c ; this value is otherwise unused, but that's sufficient for the test
   %load.ext = sext i16 %load to i32
   %load.ext.ext = sext i32 %load.ext to i64
   %exitcond740.not = icmp eq i64 %iv, %n