[VPlan] Pass debug location explicitly to VPBlendRecipe (NFC).

This enables creating VPBlendRecipes without underlying PHINode.

Author: fhahn

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -2308,14 +2308,15 @@ class LLVM_ABI_FOR_TEST VPBlendRecipe : public VPSingleDefRecipe {
   /// respective masks, ordered [I0, M0, I1, M1, I2, M2, ...]. Note that M0 can
   /// be omitted (implied by passing an odd number of operands) in which case
   /// all other incoming values are merged into it.
-  VPBlendRecipe(PHINode *Phi, ArrayRef<VPValue *> Operands)
-      : VPSingleDefRecipe(VPDef::VPBlendSC, Operands, Phi, Phi->getDebugLoc()) {
+  VPBlendRecipe(PHINode *Phi, ArrayRef<VPValue *> Operands, DebugLoc DL)
+      : VPSingleDefRecipe(VPDef::VPBlendSC, Operands, Phi, DL) {
     assert(Operands.size() > 0 && "Expected at least one operand!");
   }
 
   VPBlendRecipe *clone() override {
     SmallVector<VPValue *> Ops(operands());
-    return new VPBlendRecipe(cast<PHINode>(getUnderlyingValue()), Ops);
+    return new VPBlendRecipe(cast_or_null<PHINode>(getUnderlyingValue()), Ops,
+                             getDebugLoc());
   }
 
   VP_CLASSOF_IMPL(VPDef::VPBlendSC)

llvm/lib/Transforms/Vectorize/VPlanPredicator.cpp

@@ -251,8 +251,9 @@ void VPPredicator::convertPhisToBlends(VPBasicBlock *VPBB) {
       }
       OperandsWithMask.push_back(EdgeMask);
     }
-    PHINode *IRPhi = cast<PHINode>(PhiR->getUnderlyingValue());
-    auto *Blend = new VPBlendRecipe(IRPhi, OperandsWithMask);
+    PHINode *IRPhi = cast_or_null<PHINode>(PhiR->getUnderlyingValue());
+    auto *Blend =
+        new VPBlendRecipe(IRPhi, OperandsWithMask, PhiR->getDebugLoc());
     Builder.insert(Blend);
     PhiR->replaceAllUsesWith(Blend);
     PhiR->eraseFromParent();

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

@@ -1307,8 +1307,9 @@ static void simplifyBlends(VPlan &Plan) {
         OperandsWithMask.push_back(Blend->getMask(I));
       }
 
-      auto *NewBlend = new VPBlendRecipe(
-          cast<PHINode>(Blend->getUnderlyingValue()), OperandsWithMask);
+      auto *NewBlend =
+          new VPBlendRecipe(cast_or_null<PHINode>(Blend->getUnderlyingValue()),
+                            OperandsWithMask, Blend->getDebugLoc());
       NewBlend->insertBefore(&R);
 
       VPValue *DeadMask = Blend->getMask(StartIndex);

llvm/unittests/Transforms/Vectorize/VPlanTest.cpp

@@ -1075,7 +1075,7 @@ TEST_F(VPRecipeTest, CastVPBlendRecipeToVPUser) {
   Args.push_back(I1);
   Args.push_back(I2);
   Args.push_back(M2);
-  VPBlendRecipe Recipe(Phi, Args);
+  VPBlendRecipe Recipe(Phi, Args, {});
   EXPECT_TRUE(isa<VPUser>(&Recipe));
   VPRecipeBase *BaseR = &Recipe;
   EXPECT_TRUE(isa<VPUser>(BaseR));

llvm/unittests/Transforms/Vectorize/VPlanVerifierTest.cpp

@@ -103,7 +103,7 @@ TEST_F(VPVerifierTest, VPBlendUseBeforeDefDifferentBB) {
   auto *CanIV = new VPCanonicalIVPHIRecipe(Zero, {});
   VPInstruction *BranchOnCond =
       new VPInstruction(VPInstruction::BranchOnCond, {CanIV});
-  auto *Blend = new VPBlendRecipe(Phi, {DefI});
+  auto *Blend = new VPBlendRecipe(Phi, {DefI}, {});
 
   VPBasicBlock *VPBB1 = Plan.getEntry();
   VPBasicBlock *VPBB2 = Plan.createVPBasicBlock("");