[VPlan] Add VPWidenInduction recipe as common base class (NFC). (llvm#120008)

This helps to simplify some existing code and new code
(llvm#112145)

PR: llvm#120008

Author: fhahn

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -7941,10 +7941,8 @@ BasicBlock *EpilogueVectorizerMainLoop::createEpilogueVectorizedLoopSkeleton(
   SmallPtrSet<PHINode *, 4> WideIVs;
   for (VPRecipeBase &H :
        EPI.EpiloguePlan.getVectorLoopRegion()->getEntryBasicBlock()->phis()) {
-    if (auto *WideIV = dyn_cast<VPWidenIntOrFpInductionRecipe>(&H))
+    if (auto *WideIV = dyn_cast<VPWidenInductionRecipe>(&H))
       WideIVs.insert(WideIV->getPHINode());
-    else if (auto *PtrIV = dyn_cast<VPWidenPointerInductionRecipe>(&H))
-      WideIVs.insert(cast<PHINode>(PtrIV->getUnderlyingValue()));
   }
   createInductionResumeVPValues(ExpandedSCEVs, nullptr, &WideIVs);
 
@@ -10131,13 +10129,7 @@ preparePlanForEpilogueVectorLoop(VPlan &Plan, Loop *L,
     } else {
       // Retrieve the induction resume values for wide inductions from
       // their original phi nodes in the scalar loop.
-      PHINode *IndPhi = nullptr;
-      if (auto *Ind = dyn_cast<VPWidenPointerInductionRecipe>(&R)) {
-        IndPhi = cast<PHINode>(Ind->getUnderlyingValue());
-      } else {
-        auto *WidenInd = cast<VPWidenIntOrFpInductionRecipe>(&R);
-        IndPhi = WidenInd->getPHINode();
-      }
+      PHINode *IndPhi = cast<VPWidenInductionRecipe>(&R)->getPHINode();
       // Hook up to the PHINode generated by a ResumePhi recipe of main
       // loop VPlan, which feeds the scalar loop.
       ResumeV = IndPhi->getIncomingValueForBlock(L->getLoopPreheader());

llvm/lib/Transforms/Vectorize/VPlan.cpp

@@ -1047,7 +1047,7 @@ void VPlan::execute(VPTransformState *State) {
     if (isa<VPWidenPHIRecipe>(&R))
       continue;
 
-    if (isa<VPWidenPointerInductionRecipe, VPWidenIntOrFpInductionRecipe>(&R)) {
+    if (isa<VPWidenInductionRecipe>(&R)) {
       PHINode *Phi = nullptr;
       if (isa<VPWidenIntOrFpInductionRecipe>(&R)) {
         Phi = cast<PHINode>(State->get(R.getVPSingleValue()));

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -2099,38 +2099,81 @@ class VPHeaderPHIRecipe : public VPSingleDefRecipe {
   }
 };
 
+/// Base class for widened induction (VPWidenIntOrFpInductionRecipe and
+/// VPWidenPointerInductionRecipe), providing shared functionality, including
+/// retrieving the step value, induction descriptor and original phi node.
+class VPWidenInductionRecipe : public VPHeaderPHIRecipe {
+  const InductionDescriptor &IndDesc;
+
+public:
+  VPWidenInductionRecipe(unsigned char Kind, PHINode *IV, VPValue *Start,
+                         VPValue *Step, const InductionDescriptor &IndDesc,
+                         DebugLoc DL)
+      : VPHeaderPHIRecipe(Kind, IV, Start, DL), IndDesc(IndDesc) {
+    addOperand(Step);
+  }
+
+  static inline bool classof(const VPRecipeBase *R) {
+    return R->getVPDefID() == VPDef::VPWidenIntOrFpInductionSC ||
+           R->getVPDefID() == VPDef::VPWidenPointerInductionSC;
+  }
+
+  virtual void execute(VPTransformState &State) override = 0;
+
+  /// Returns the step value of the induction.
+  VPValue *getStepValue() { return getOperand(1); }
+  const VPValue *getStepValue() const { return getOperand(1); }
+
+  PHINode *getPHINode() const { return cast<PHINode>(getUnderlyingValue()); }
+
+  /// Returns the induction descriptor for the recipe.
+  const InductionDescriptor &getInductionDescriptor() const { return IndDesc; }
+
+  VPValue *getBackedgeValue() override {
+    // TODO: All operands of base recipe must exist and be at same index in
+    // derived recipe.
+    llvm_unreachable(
+        "VPWidenIntOrFpInductionRecipe generates its own backedge value");
+  }
+
+  VPRecipeBase &getBackedgeRecipe() override {
+    // TODO: All operands of base recipe must exist and be at same index in
+    // derived recipe.
+    llvm_unreachable(
+        "VPWidenIntOrFpInductionRecipe generates its own backedge value");
+  }
+};
+
 /// A recipe for handling phi nodes of integer and floating-point inductions,
 /// producing their vector values.
-class VPWidenIntOrFpInductionRecipe : public VPHeaderPHIRecipe {
-  PHINode *IV;
+class VPWidenIntOrFpInductionRecipe : public VPWidenInductionRecipe {
   TruncInst *Trunc;
-  const InductionDescriptor &IndDesc;
 
 public:
   VPWidenIntOrFpInductionRecipe(PHINode *IV, VPValue *Start, VPValue *Step,
                                 VPValue *VF, const InductionDescriptor &IndDesc,
                                 DebugLoc DL)
-      : VPHeaderPHIRecipe(VPDef::VPWidenIntOrFpInductionSC, IV, Start, DL),
-        IV(IV), Trunc(nullptr), IndDesc(IndDesc) {
-    addOperand(Step);
+      : VPWidenInductionRecipe(VPDef::VPWidenIntOrFpInductionSC, IV, Start,
+                               Step, IndDesc, DL),
+        Trunc(nullptr) {
     addOperand(VF);
   }
 
   VPWidenIntOrFpInductionRecipe(PHINode *IV, VPValue *Start, VPValue *Step,
                                 VPValue *VF, const InductionDescriptor &IndDesc,
                                 TruncInst *Trunc, DebugLoc DL)
-      : VPHeaderPHIRecipe(VPDef::VPWidenIntOrFpInductionSC, Trunc, Start, DL),
-        IV(IV), Trunc(Trunc), IndDesc(IndDesc) {
-    addOperand(Step);
+      : VPWidenInductionRecipe(VPDef::VPWidenIntOrFpInductionSC, IV, Start,
+                               Step, IndDesc, DL),
+        Trunc(Trunc) {
     addOperand(VF);
   }
 
   ~VPWidenIntOrFpInductionRecipe() override = default;
 
   VPWidenIntOrFpInductionRecipe *clone() override {
-    return new VPWidenIntOrFpInductionRecipe(IV, getStartValue(),
-                                             getStepValue(), getVFValue(),
-                                             IndDesc, Trunc, getDebugLoc());
+    return new VPWidenIntOrFpInductionRecipe(
+        getPHINode(), getStartValue(), getStepValue(), getVFValue(),
+        getInductionDescriptor(), Trunc, getDebugLoc());
   }
 
   VP_CLASSOF_IMPL(VPDef::VPWidenIntOrFpInductionSC)
@@ -2145,24 +2188,6 @@ class VPWidenIntOrFpInductionRecipe : public VPHeaderPHIRecipe {
              VPSlotTracker &SlotTracker) const override;
 #endif
 
-  VPValue *getBackedgeValue() override {
-    // TODO: All operands of base recipe must exist and be at same index in
-    // derived recipe.
-    llvm_unreachable(
-        "VPWidenIntOrFpInductionRecipe generates its own backedge value");
-  }
-
-  VPRecipeBase &getBackedgeRecipe() override {
-    // TODO: All operands of base recipe must exist and be at same index in
-    // derived recipe.
-    llvm_unreachable(
-        "VPWidenIntOrFpInductionRecipe generates its own backedge value");
-  }
-
-  /// Returns the step value of the induction.
-  VPValue *getStepValue() { return getOperand(1); }
-  const VPValue *getStepValue() const { return getOperand(1); }
-
   VPValue *getVFValue() { return getOperand(2); }
   const VPValue *getVFValue() const { return getOperand(2); }
 
@@ -2177,19 +2202,14 @@ class VPWidenIntOrFpInductionRecipe : public VPHeaderPHIRecipe {
   TruncInst *getTruncInst() { return Trunc; }
   const TruncInst *getTruncInst() const { return Trunc; }
 
-  PHINode *getPHINode() { return IV; }
-
-  /// Returns the induction descriptor for the recipe.
-  const InductionDescriptor &getInductionDescriptor() const { return IndDesc; }
-
   /// Returns true if the induction is canonical, i.e. starting at 0 and
   /// incremented by UF * VF (= the original IV is incremented by 1) and has the
   /// same type as the canonical induction.
   bool isCanonical() const;
 
   /// Returns the scalar type of the induction.
   Type *getScalarType() const {
-    return Trunc ? Trunc->getType() : IV->getType();
+    return Trunc ? Trunc->getType() : getPHINode()->getType();
   }
 
   /// Returns the VPValue representing the value of this induction at
@@ -2200,10 +2220,8 @@ class VPWidenIntOrFpInductionRecipe : public VPHeaderPHIRecipe {
   }
 };
 
-class VPWidenPointerInductionRecipe : public VPHeaderPHIRecipe,
+class VPWidenPointerInductionRecipe : public VPWidenInductionRecipe,
                                       public VPUnrollPartAccessor<3> {
-  const InductionDescriptor &IndDesc;
-
   bool IsScalarAfterVectorization;
 
 public:
@@ -2212,19 +2230,16 @@ class VPWidenPointerInductionRecipe : public VPHeaderPHIRecipe,
   VPWidenPointerInductionRecipe(PHINode *Phi, VPValue *Start, VPValue *Step,
                                 const InductionDescriptor &IndDesc,
                                 bool IsScalarAfterVectorization, DebugLoc DL)
-      : VPHeaderPHIRecipe(VPDef::VPWidenPointerInductionSC, Phi, nullptr, DL),
-        IndDesc(IndDesc),
-        IsScalarAfterVectorization(IsScalarAfterVectorization) {
-    addOperand(Start);
-    addOperand(Step);
-  }
+      : VPWidenInductionRecipe(VPDef::VPWidenPointerInductionSC, Phi, Start,
+                               Step, IndDesc, DL),
+        IsScalarAfterVectorization(IsScalarAfterVectorization) {}
 
   ~VPWidenPointerInductionRecipe() override = default;
 
   VPWidenPointerInductionRecipe *clone() override {
     return new VPWidenPointerInductionRecipe(
         cast<PHINode>(getUnderlyingInstr()), getOperand(0), getOperand(1),
-        IndDesc, IsScalarAfterVectorization, getDebugLoc());
+        getInductionDescriptor(), IsScalarAfterVectorization, getDebugLoc());
   }
 
   VP_CLASSOF_IMPL(VPDef::VPWidenPointerInductionSC)
@@ -2235,9 +2250,6 @@ class VPWidenPointerInductionRecipe : public VPHeaderPHIRecipe,
   /// Returns true if only scalar values will be generated.
   bool onlyScalarsGenerated(bool IsScalable);
 
-  /// Returns the induction descriptor for the recipe.
-  const InductionDescriptor &getInductionDescriptor() const { return IndDesc; }
-
   /// Returns the VPValue representing the value of this induction at
   /// the first unrolled part, if it exists. Returns itself if unrolling did not
   /// take place.

llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp

@@ -1655,12 +1655,13 @@ void VPWidenIntOrFpInductionRecipe::execute(VPTransformState &State) {
   const InductionDescriptor &ID = getInductionDescriptor();
   TruncInst *Trunc = getTruncInst();
   IRBuilderBase &Builder = State.Builder;
-  assert(IV->getType() == ID.getStartValue()->getType() && "Types must match");
+  assert(getPHINode()->getType() == ID.getStartValue()->getType() &&
+         "Types must match");
   assert(State.VF.isVector() && "must have vector VF");
 
   // The value from the original loop to which we are mapping the new induction
   // variable.
-  Instruction *EntryVal = Trunc ? cast<Instruction>(Trunc) : IV;
+  Instruction *EntryVal = Trunc ? cast<Instruction>(Trunc) : getPHINode();
 
   // Fast-math-flags propagate from the original induction instruction.
   IRBuilder<>::FastMathFlagGuard FMFG(Builder);
@@ -3144,7 +3145,8 @@ bool VPWidenPointerInductionRecipe::onlyScalarsGenerated(bool IsScalable) {
 }
 
 void VPWidenPointerInductionRecipe::execute(VPTransformState &State) {
-  assert(IndDesc.getKind() == InductionDescriptor::IK_PtrInduction &&
+  assert(getInductionDescriptor().getKind() ==
+             InductionDescriptor::IK_PtrInduction &&
          "Not a pointer induction according to InductionDescriptor!");
   assert(cast<PHINode>(getUnderlyingInstr())->getType()->isPointerTy() &&
          "Unexpected type.");
@@ -3180,8 +3182,8 @@ void VPWidenPointerInductionRecipe::execute(VPTransformState &State) {
 
   // A pointer induction, performed by using a gep
   BasicBlock::iterator InductionLoc = State.Builder.GetInsertPoint();
-  Value *ScalarStepValue = State.get(getOperand(1), VPLane(0));
-  Type *PhiType = State.TypeAnalysis.inferScalarType(getOperand(1));
+  Value *ScalarStepValue = State.get(getStepValue(), VPLane(0));
+  Type *PhiType = State.TypeAnalysis.inferScalarType(getStepValue());
   Value *RuntimeVF = getRuntimeVF(State.Builder, PhiType, State.VF);
   // Add induction update using an incorrect block temporarily. The phi node
   // will be fixed after VPlan execution. Note that at this point the latch
@@ -3234,7 +3236,7 @@ void VPWidenPointerInductionRecipe::print(raw_ostream &O, const Twine &Indent,
   O << " = WIDEN-POINTER-INDUCTION ";
   getStartValue()->printAsOperand(O, SlotTracker);
   O << ", ";
-  getOperand(1)->printAsOperand(O, SlotTracker);
+  getStepValue()->printAsOperand(O, SlotTracker);
   if (getNumOperands() == 4) {
     O << ", ";
     getOperand(2)->printAsOperand(O, SlotTracker);

llvm/test/Transforms/LoopVectorize/vplan-printing.ll

@@ -653,10 +653,10 @@ define void @print_expand_scev(i64 %y, ptr %ptr) {
 ; CHECK-NEXT: <x1> vector loop: {
 ; CHECK-NEXT:   vector.body:
 ; CHECK-NEXT:     EMIT vp<[[CAN_IV:%.+]]> = CANONICAL-INDUCTION ir<0>, vp<[[CAN_IV_NEXT:%.+]]>
-; CHECK-NEXT:     ir<%v2> = WIDEN-INDUCTION ir<0>, vp<[[EXP_SCEV]]>, vp<[[VF]]> (truncated to i8)
+; CHECK-NEXT:     ir<%iv> = WIDEN-INDUCTION ir<0>, vp<[[EXP_SCEV]]>, vp<[[VF]]> (truncated to i8)
 ; CHECK-NEXT:     vp<[[DERIVED_IV:%.+]]> = DERIVED-IV ir<0> + vp<[[CAN_IV]]> * vp<[[EXP_SCEV]]>
 ; CHECK-NEXT:     vp<[[STEPS:%.+]]> = SCALAR-STEPS vp<[[DERIVED_IV]]>, vp<[[EXP_SCEV]]>
-; CHECK-NEXT:     WIDEN ir<%v3> = add nuw ir<%v2>, ir<1>
+; CHECK-NEXT:     WIDEN ir<%v3> = add nuw ir<%iv>, ir<1>
 ; CHECK-NEXT:     REPLICATE ir<%gep> = getelementptr inbounds ir<%ptr>, vp<[[STEPS]]>
 ; CHECK-NEXT:     REPLICATE store ir<%v3>, ir<%gep>
 ; CHECK-NEXT:     EMIT vp<[[CAN_IV_NEXT]]> = add nuw vp<[[CAN_IV]]>, vp<[[VFxUF]]>