Address review

Author: SamTebbs33

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

@@ -3543,12 +3543,14 @@ tryToMatchAndCreateMulAccumulateReduction(VPReductionRecipe *Red,
   };
 
   VPValue *VecOp = Red->getVecOp();
-  VPValue *Sub = nullptr;
+  VPRecipeBase *Sub = nullptr;
   VPValue *A, *B;
+  VPValue *Tmp = nullptr;
   // Sub reductions could have a sub between the add reduction and vec op.
-  if (match(VecOp, m_Binary<Instruction::Sub>(m_SpecificInt(0), m_VPValue()))) {
-    Sub = VecOp;
-    VecOp = cast<VPWidenRecipe>(VecOp->getDefiningRecipe())->getOperand(1);
+  if (match(VecOp,
+            m_Binary<Instruction::Sub>(m_SpecificInt(0), m_VPValue(Tmp)))) {
+    Sub = VecOp->getDefiningRecipe();
+    VecOp = Tmp;
   }
   // Try to match reduce.add(mul(...)).
   if (match(VecOp, m_Mul(m_VPValue(A), m_VPValue(B)))) {
@@ -3567,9 +3569,8 @@ tryToMatchAndCreateMulAccumulateReduction(VPReductionRecipe *Red,
                                        Instruction::CastOps::ZExt,
                                    Mul, RecipeA, RecipeB, nullptr)) {
       if (Sub)
-        return new VPExpressionRecipe(
-            RecipeA, RecipeB, Mul,
-            cast<VPWidenRecipe>(Sub->getDefiningRecipe()), Red);
+        return new VPExpressionRecipe(RecipeA, RecipeB, Mul,
+                                      cast<VPWidenRecipe>(Sub), Red);
       return new VPExpressionRecipe(RecipeA, RecipeB, Mul, Red);
     }
     // Match reduce.add(mul).
@@ -3578,12 +3579,15 @@ tryToMatchAndCreateMulAccumulateReduction(VPReductionRecipe *Red,
         IsMulAccValidAndClampRange(true, Mul, nullptr, nullptr, nullptr))
       return new VPExpressionRecipe(Mul, Red);
   }
+  // TODO: Add an expression type for negated versions of other expression
+  // variants.
+  if (Sub)
+    return nullptr;
   // Match reduce.add(ext(mul(ext(A), ext(B)))).
   // All extend recipes must have same opcode or A == B
   // which can be transform to reduce.add(zext(mul(sext(A), sext(B)))).
-  // TODO: Add an expression type for this variant with a negated mul
-  if (!Sub && match(VecOp, m_ZExtOrSExt(m_Mul(m_ZExtOrSExt(m_VPValue()),
-                                              m_ZExtOrSExt(m_VPValue()))))) {
+  if (match(VecOp, m_ZExtOrSExt(m_Mul(m_ZExtOrSExt(m_VPValue()),
+                                      m_ZExtOrSExt(m_VPValue()))))) {
     auto *Ext = cast<VPWidenCastRecipe>(VecOp->getDefiningRecipe());
     auto *Mul = cast<VPWidenRecipe>(Ext->getOperand(0)->getDefiningRecipe());
     auto *Ext0 =