[llvm] VPlan: implement VPlan-level constant-folding (PR #125365)

Ramkumar Ramachandra via llvm-commits llvm-commits at lists.llvm.org
Sat Feb 1 14:15:20 PST 2025


https://github.com/artagnon created https://github.com/llvm/llvm-project/pull/125365

Introduce VPlanConstantFolder, a variation of ConstantFolder for VPlan, and use it in VPBuilder to constant-fold when all the underlying IR values passed into the API are constants.

-- 8< --
Based on #125364.

>From f13968990fbc9dd8418c29c0ea919f8d6ebb4084 Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <ramkumar.ramachandra at codasip.com>
Date: Sat, 1 Feb 2025 14:48:27 +0000
Subject: [PATCH 1/2] VPlan: thread plan to VPBuilder (NFC)

Construct VPBuilder with a VPlan object, and change VPRecipeBuilder to
own the VPBuilder, in preparation to use the VPlan object in VPBuilder
to implement constant-folding. The VPlan reference in VPBuilder is
unused for now.
---
 .../Vectorize/LoopVectorizationPlanner.h      | 25 +++++++----------
 .../Transforms/Vectorize/LoopVectorize.cpp    | 27 +++++++++----------
 .../Transforms/Vectorize/VPRecipeBuilder.h    | 11 +++++---
 llvm/lib/Transforms/Vectorize/VPlan.cpp       |  2 +-
 .../Transforms/Vectorize/VPlanHCFGBuilder.cpp |  2 +-
 .../Transforms/Vectorize/VPlanTransforms.cpp  | 21 ++++++++-------
 llvm/lib/Transforms/Vectorize/VPlanUnroll.cpp |  2 +-
 7 files changed, 44 insertions(+), 46 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h b/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
index bc44ec11edb7b0..76e7bf2f62650a 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
@@ -25,7 +25,6 @@
 #define LLVM_TRANSFORMS_VECTORIZE_LOOPVECTORIZATIONPLANNER_H
 
 #include "VPlan.h"
-#include "llvm/ADT/SmallSet.h"
 #include "llvm/Support/InstructionCost.h"
 
 namespace llvm {
@@ -45,6 +44,7 @@ class VPRecipeBuilder;
 class VPBuilder {
   VPBasicBlock *BB = nullptr;
   VPBasicBlock::iterator InsertPt = VPBasicBlock::iterator();
+  [[maybe_unused]] VPlan &Plan;
 
   /// Insert \p VPI in BB at InsertPt if BB is set.
   template <typename T> T *tryInsertInstruction(T *R) {
@@ -66,10 +66,15 @@ class VPBuilder {
   }
 
 public:
-  VPBuilder() = default;
-  VPBuilder(VPBasicBlock *InsertBB) { setInsertPoint(InsertBB); }
-  VPBuilder(VPRecipeBase *InsertPt) { setInsertPoint(InsertPt); }
-  VPBuilder(VPBasicBlock *TheBB, VPBasicBlock::iterator IP) {
+  VPBuilder(VPlan &Plan) : Plan(Plan) {}
+  VPBuilder(VPlan &Plan, VPBasicBlock *InsertBB) : Plan(Plan) {
+    setInsertPoint(InsertBB);
+  }
+  VPBuilder(VPlan &Plan, VPRecipeBase *InsertPt) : Plan(Plan) {
+    setInsertPoint(InsertPt);
+  }
+  VPBuilder(VPlan &Plan, VPBasicBlock *TheBB, VPBasicBlock::iterator IP)
+      : Plan(Plan) {
     setInsertPoint(TheBB, IP);
   }
 
@@ -83,13 +88,6 @@ class VPBuilder {
   VPBasicBlock *getInsertBlock() const { return BB; }
   VPBasicBlock::iterator getInsertPoint() const { return InsertPt; }
 
-  /// Create a VPBuilder to insert after \p R.
-  static VPBuilder getToInsertAfter(VPRecipeBase *R) {
-    VPBuilder B;
-    B.setInsertPoint(R->getParent(), std::next(R->getIterator()));
-    return B;
-  }
-
   /// InsertPoint - A saved insertion point.
   class VPInsertPoint {
     VPBasicBlock *Block = nullptr;
@@ -390,9 +388,6 @@ class LoopVectorizationPlanner {
   /// Profitable vector factors.
   SmallVector<VectorizationFactor, 8> ProfitableVFs;
 
-  /// A builder used to construct the current plan.
-  VPBuilder Builder;
-
   /// Computes the cost of \p Plan for vectorization factor \p VF.
   ///
   /// The current implementation requires access to the
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 493ce848171211..858eddae56943b 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -8947,7 +8947,7 @@ static void addCanonicalIVRecipes(VPlan &Plan, Type *IdxTy, bool HasNUW,
   VPBasicBlock *Header = TopRegion->getEntryBasicBlock();
   Header->insert(CanonicalIVPHI, Header->begin());
 
-  VPBuilder Builder(TopRegion->getExitingBasicBlock());
+  VPBuilder Builder(Plan, TopRegion->getExitingBasicBlock());
   // Add a VPInstruction to increment the scalar canonical IV by VF * UF.
   auto *CanonicalIVIncrement = Builder.createOverflowingOp(
       Instruction::Add, {CanonicalIVPHI, &Plan.getVFxUF()}, {HasNUW, false}, DL,
@@ -9007,9 +9007,9 @@ static void addScalarResumePhis(VPRecipeBuilder &Builder, VPlan &Plan,
   auto *MiddleVPBB = cast<VPBasicBlock>(ScalarPH->getSinglePredecessor());
   VPRegionBlock *VectorRegion = Plan.getVectorLoopRegion();
   VPBuilder VectorPHBuilder(
-      cast<VPBasicBlock>(VectorRegion->getSinglePredecessor()));
-  VPBuilder MiddleBuilder(MiddleVPBB, MiddleVPBB->getFirstNonPhi());
-  VPBuilder ScalarPHBuilder(ScalarPH);
+      Plan, cast<VPBasicBlock>(VectorRegion->getSinglePredecessor()));
+  VPBuilder MiddleBuilder(Plan, MiddleVPBB, MiddleVPBB->getFirstNonPhi());
+  VPBuilder ScalarPHBuilder(Plan, ScalarPH);
   VPValue *OneVPV = Plan.getOrAddLiveIn(
       ConstantInt::get(Plan.getCanonicalIV()->getScalarType(), 1));
   for (VPRecipeBase &ScalarPhiR : *Plan.getScalarHeader()) {
@@ -9101,7 +9101,7 @@ addUsersInExitBlocks(VPlan &Plan,
     return;
 
   auto *MiddleVPBB = Plan.getMiddleBlock();
-  VPBuilder B(MiddleVPBB, MiddleVPBB->getFirstNonPhi());
+  VPBuilder B(Plan, MiddleVPBB, MiddleVPBB->getFirstNonPhi());
 
   // Introduce extract for exiting values and update the VPIRInstructions
   // modeling the corresponding LCSSA phis.
@@ -9123,8 +9123,8 @@ static void addExitUsersForFirstOrderRecurrences(
   VPRegionBlock *VectorRegion = Plan.getVectorLoopRegion();
   auto *ScalarPHVPBB = Plan.getScalarPreheader();
   auto *MiddleVPBB = Plan.getMiddleBlock();
-  VPBuilder ScalarPHBuilder(ScalarPHVPBB);
-  VPBuilder MiddleBuilder(MiddleVPBB, MiddleVPBB->getFirstNonPhi());
+  VPBuilder ScalarPHBuilder(Plan, ScalarPHVPBB);
+  VPBuilder MiddleBuilder(Plan, MiddleVPBB, MiddleVPBB->getFirstNonPhi());
   VPValue *TwoVPV = Plan.getOrAddLiveIn(
       ConstantInt::get(Plan.getCanonicalIV()->getScalarType(), 2));
 
@@ -9261,8 +9261,7 @@ LoopVectorizationPlanner::tryToBuildVPlanWithVPRecipes(VFRange &Range) {
   bool HasNUW = !IVUpdateMayOverflow || Style == TailFoldingStyle::None;
   addCanonicalIVRecipes(*Plan, Legal->getWidestInductionType(), HasNUW, DL);
 
-  VPRecipeBuilder RecipeBuilder(*Plan, OrigLoop, TLI, &TTI, Legal, CM, PSE,
-                                Builder);
+  VPRecipeBuilder RecipeBuilder(*Plan, OrigLoop, TLI, &TTI, Legal, CM, PSE);
 
   // ---------------------------------------------------------------------------
   // Pre-construction: record ingredients whose recipes we'll need to further
@@ -9318,7 +9317,7 @@ LoopVectorizationPlanner::tryToBuildVPlanWithVPRecipes(VFRange &Range) {
     // ingredients and fill a new VPBasicBlock.
     if (VPBB != HeaderVPBB)
       VPBB->setName(BB->getName());
-    Builder.setInsertPoint(VPBB);
+    RecipeBuilder.setInsertPoint(VPBB);
 
     if (VPBB == HeaderVPBB)
       RecipeBuilder.createHeaderMask();
@@ -9482,7 +9481,7 @@ LoopVectorizationPlanner::tryToBuildVPlanWithVPRecipes(VFRange &Range) {
   // Sink users of fixed-order recurrence past the recipe defining the previous
   // value and introduce FirstOrderRecurrenceSplice VPInstructions.
   if (!VPlanTransforms::runPass(VPlanTransforms::adjustFixedOrderRecurrences,
-                                *Plan, Builder))
+                                *Plan, RecipeBuilder.getIRBuilder()))
     return nullptr;
 
   if (useActiveLaneMask(Style)) {
@@ -9532,8 +9531,7 @@ VPlanPtr LoopVectorizationPlanner::buildVPlan(VFRange &Range) {
 
   // Collect mapping of IR header phis to header phi recipes, to be used in
   // addScalarResumePhis.
-  VPRecipeBuilder RecipeBuilder(*Plan, OrigLoop, TLI, &TTI, Legal, CM, PSE,
-                                Builder);
+  VPRecipeBuilder RecipeBuilder(*Plan, OrigLoop, TLI, &TTI, Legal, CM, PSE);
   for (auto &R : Plan->getVectorLoopRegion()->getEntryBasicBlock()->phis()) {
     if (isa<VPCanonicalIVPHIRecipe>(&R))
       continue;
@@ -9698,6 +9696,7 @@ void LoopVectorizationPlanner::adjustRecipesForReductions(
     }
   }
   VPBasicBlock *LatchVPBB = VectorLoopRegion->getExitingBasicBlock();
+  VPBuilder Builder(*Plan);
   Builder.setInsertPoint(&*LatchVPBB->begin());
   VPBasicBlock::iterator IP = MiddleVPBB->getFirstNonPhi();
   for (VPRecipeBase &R :
@@ -10205,7 +10204,7 @@ static void preparePlanForMainVectorLoop(VPlan &MainPlan, VPlan &EpiPlan) {
                              m_Specific(VectorTC), m_SpecificInt(0)));
       }))
     return;
-  VPBuilder ScalarPHBuilder(MainScalarPH, MainScalarPH->begin());
+  VPBuilder ScalarPHBuilder(MainPlan, MainScalarPH, MainScalarPH->begin());
   ScalarPHBuilder.createNaryOp(
       VPInstruction::ResumePhi,
       {VectorTC, MainPlan.getCanonicalIV()->getStartValue()}, {},
diff --git a/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h b/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
index 87c97d1edd7b6a..c9c3a1abec5283 100644
--- a/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
+++ b/llvm/lib/Transforms/Vectorize/VPRecipeBuilder.h
@@ -12,7 +12,6 @@
 #include "LoopVectorizationPlanner.h"
 #include "VPlan.h"
 #include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/PointerUnion.h"
 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
 #include "llvm/IR/IRBuilder.h"
 
@@ -65,7 +64,7 @@ class VPRecipeBuilder {
 
   PredicatedScalarEvolution &PSE;
 
-  VPBuilder &Builder;
+  VPBuilder Builder;
 
   /// When we if-convert we need to create edge masks. We have to cache values
   /// so that we don't end up with exponential recursion/IR. Note that
@@ -155,9 +154,13 @@ class VPRecipeBuilder {
                   const TargetTransformInfo *TTI,
                   LoopVectorizationLegality *Legal,
                   LoopVectorizationCostModel &CM,
-                  PredicatedScalarEvolution &PSE, VPBuilder &Builder)
+                  PredicatedScalarEvolution &PSE)
       : Plan(Plan), OrigLoop(OrigLoop), TLI(TLI), TTI(TTI), Legal(Legal),
-        CM(CM), PSE(PSE), Builder(Builder) {}
+        CM(CM), PSE(PSE), Builder(Plan) {}
+
+  void setInsertPoint(VPBasicBlock *VPBB) { Builder.setInsertPoint(VPBB); }
+
+  VPBuilder &getIRBuilder() { return Builder; }
 
   std::optional<unsigned> getScalingForReduction(const Instruction *ExitInst) {
     auto It = ScaledReductionMap.find(ExitInst);
diff --git a/llvm/lib/Transforms/Vectorize/VPlan.cpp b/llvm/lib/Transforms/Vectorize/VPlan.cpp
index 4a1512abe4e48c..5f7a69fd35a088 100644
--- a/llvm/lib/Transforms/Vectorize/VPlan.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlan.cpp
@@ -915,7 +915,7 @@ VPlanPtr VPlan::createInitialVPlan(Type *InductionTy,
   // of the corresponding compare because they may have ended up with
   // different line numbers and we want to avoid awkward line stepping while
   // debugging. Eg. if the compare has got a line number inside the loop.
-  VPBuilder Builder(MiddleVPBB);
+  VPBuilder Builder(*Plan, MiddleVPBB);
   VPValue *Cmp =
       TailFolded
           ? Plan->getOrAddLiveIn(ConstantInt::getTrue(
diff --git a/llvm/lib/Transforms/Vectorize/VPlanHCFGBuilder.cpp b/llvm/lib/Transforms/Vectorize/VPlanHCFGBuilder.cpp
index 5a2e5d7cfee48d..a0505e0d1bb8d0 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanHCFGBuilder.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanHCFGBuilder.cpp
@@ -72,7 +72,7 @@ class PlainCFGBuilder {
 
 public:
   PlainCFGBuilder(Loop *Lp, LoopInfo *LI, VPlan &P)
-      : TheLoop(Lp), LI(LI), Plan(P) {}
+      : TheLoop(Lp), LI(LI), Plan(P), VPIRBuilder(Plan) {}
 
   /// Build plain CFG for TheLoop  and connects it to Plan's entry.
   void buildPlainCFG();
diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index a1a2cf211abf88..bf95b62474150c 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -591,7 +591,7 @@ static void legalizeAndOptimizeInductions(VPlan &Plan) {
   using namespace llvm::VPlanPatternMatch;
   VPBasicBlock *HeaderVPBB = Plan.getVectorLoopRegion()->getEntryBasicBlock();
   bool HasOnlyVectorVFs = !Plan.hasVF(ElementCount::getFixed(1));
-  VPBuilder Builder(HeaderVPBB, HeaderVPBB->getFirstNonPhi());
+  VPBuilder Builder(Plan, HeaderVPBB, HeaderVPBB->getFirstNonPhi());
   for (VPRecipeBase &Phi : HeaderVPBB->phis()) {
     auto *PhiR = dyn_cast<VPWidenInductionRecipe>(&Phi);
     if (!PhiR)
@@ -744,7 +744,7 @@ void VPlanTransforms::optimizeInductionExitUsers(
          "predecessor must be the middle block");
 
   VPTypeAnalysis TypeInfo(Plan.getCanonicalIV()->getScalarType());
-  VPBuilder B(Plan.getMiddleBlock()->getTerminator());
+  VPBuilder B(Plan, Plan.getMiddleBlock()->getTerminator());
   for (VPRecipeBase &R : *ExitVPBB) {
     auto *ExitIRI = cast<VPIRInstruction>(&R);
     if (!isa<PHINode>(ExitIRI->getInstruction()))
@@ -1505,7 +1505,7 @@ static VPActiveLaneMaskPHIRecipe *addVPLaneMaskPhiAndUpdateExitBranch(
   // we have to take unrolling into account. Each part needs to start at
   //   Part * VF
   auto *VecPreheader = Plan.getVectorPreheader();
-  VPBuilder Builder(VecPreheader);
+  VPBuilder Builder(Plan, VecPreheader);
 
   // Create the ActiveLaneMask instruction using the correct start values.
   VPValue *TC = Plan.getTripCount();
@@ -1624,7 +1624,8 @@ void VPlanTransforms::addActiveLaneMask(
     LaneMask = addVPLaneMaskPhiAndUpdateExitBranch(
         Plan, DataAndControlFlowWithoutRuntimeCheck);
   } else {
-    VPBuilder B = VPBuilder::getToInsertAfter(WideCanonicalIV);
+    VPBuilder B(Plan, WideCanonicalIV->getParent(),
+                std::next(WideCanonicalIV->getIterator()));
     LaneMask = B.createNaryOp(VPInstruction::ActiveLaneMask,
                               {WideCanonicalIV, Plan.getTripCount()}, nullptr,
                               "active.lane.mask");
@@ -1828,7 +1829,7 @@ bool VPlanTransforms::tryAddExplicitVectorLength(
   // Create the ExplicitVectorLengthPhi recipe in the main loop.
   auto *EVLPhi = new VPEVLBasedIVPHIRecipe(StartV, DebugLoc());
   EVLPhi->insertAfter(CanonicalIVPHI);
-  VPBuilder Builder(Header, Header->getFirstNonPhi());
+  VPBuilder Builder(Plan, Header, Header->getFirstNonPhi());
   // Compute original TC - IV as the AVL (application vector length).
   VPValue *AVL = Builder.createNaryOp(
       Instruction::Sub, {Plan.getTripCount(), EVLPhi}, DebugLoc(), "avl");
@@ -1909,7 +1910,7 @@ void VPlanTransforms::dropPoisonGeneratingRecipes(
         // where the operands are disjoint or poison otherwise.
         if (match(RecWithFlags, m_BinaryOr(m_VPValue(A), m_VPValue(B))) &&
             RecWithFlags->isDisjoint()) {
-          VPBuilder Builder(RecWithFlags);
+          VPBuilder Builder(Plan, RecWithFlags);
           VPInstruction *New = Builder.createOverflowingOp(
               Instruction::Add, {A, B}, {false, false},
               RecWithFlags->getDebugLoc());
@@ -2023,7 +2024,7 @@ void VPlanTransforms::createInterleaveGroups(
                    /*IsSigned=*/true);
       VPValue *OffsetVPV = Plan.getOrAddLiveIn(
           ConstantInt::get(IRInsertPos->getParent()->getContext(), -Offset));
-      VPBuilder B(InsertPos);
+      VPBuilder B(Plan, InsertPos);
       Addr = InBounds ? B.createInBoundsPtrAdd(InsertPos->getAddr(), OffsetVPV)
                       : B.createPtrAdd(InsertPos->getAddr(), OffsetVPV);
     }
@@ -2069,7 +2070,7 @@ void VPlanTransforms::handleUncountableEarlyExit(
     BasicBlock *UncountableExitingBlock, VPRecipeBuilder &RecipeBuilder) {
   VPRegionBlock *LoopRegion = Plan.getVectorLoopRegion();
   auto *LatchVPBB = cast<VPBasicBlock>(LoopRegion->getExiting());
-  VPBuilder Builder(LatchVPBB->getTerminator());
+  VPBuilder Builder(Plan, LatchVPBB->getTerminator());
   auto *MiddleVPBB = Plan.getMiddleBlock();
   VPValue *IsEarlyExitTaken = nullptr;
 
@@ -2110,8 +2111,8 @@ void VPlanTransforms::handleUncountableEarlyExit(
   VPBlockUtils::connectBlocks(VectorEarlyExitVPBB, VPEarlyExitBlock);
 
   // Update the exit phis in the early exit block.
-  VPBuilder MiddleBuilder(NewMiddle);
-  VPBuilder EarlyExitB(VectorEarlyExitVPBB);
+  VPBuilder MiddleBuilder(Plan, NewMiddle);
+  VPBuilder EarlyExitB(Plan, VectorEarlyExitVPBB);
   for (VPRecipeBase &R : *VPEarlyExitBlock) {
     auto *ExitIRI = cast<VPIRInstruction>(&R);
     auto *ExitPhi = dyn_cast<PHINode>(&ExitIRI->getInstruction());
diff --git a/llvm/lib/Transforms/Vectorize/VPlanUnroll.cpp b/llvm/lib/Transforms/Vectorize/VPlanUnroll.cpp
index 89e372d6b46cfd..53e086dfe1cbd4 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanUnroll.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanUnroll.cpp
@@ -156,7 +156,7 @@ void UnrollState::unrollWidenInductionByUF(
     FMFs = ID.getInductionBinOp()->getFastMathFlags();
 
   VPValue *VectorStep = &Plan.getVF();
-  VPBuilder Builder(PH);
+  VPBuilder Builder(Plan, PH);
   if (TypeInfo.inferScalarType(VectorStep) != IVTy) {
     Instruction::CastOps CastOp =
         IVTy->isFloatingPointTy() ? Instruction::UIToFP : Instruction::Trunc;

>From c06b65b960e61686b5293ad2157a4b840e956790 Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <ramkumar.ramachandra at codasip.com>
Date: Sat, 1 Feb 2025 20:32:51 +0000
Subject: [PATCH 2/2] VPlan: implement VPlan-level constant-folding

Introduce VPlanConstantFolder, a variation of ConstantFolder for VPlan,
and use it in VPBuilder to constant-fold when all the underlying IR
values passed into the API are constants.
---
 .../Vectorize/LoopVectorizationPlanner.h      | 37 +++++--
 .../Vectorize/VPlanConstantFolder.h           | 96 +++++++++++++++++++
 .../Transforms/Vectorize/VPlanTransforms.cpp  |  4 +-
 ...licate-recipe-with-only-first-lane-used.ll | 50 +---------
 .../interleave-and-scalarize-only.ll          |  5 +-
 5 files changed, 131 insertions(+), 61 deletions(-)
 create mode 100644 llvm/lib/Transforms/Vectorize/VPlanConstantFolder.h

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h b/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
index 76e7bf2f62650a..cfbc075e6dcd7d 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
@@ -25,6 +25,7 @@
 #define LLVM_TRANSFORMS_VECTORIZE_LOOPVECTORIZATIONPLANNER_H
 
 #include "VPlan.h"
+#include "VPlanConstantFolder.h"
 #include "llvm/Support/InstructionCost.h"
 
 namespace llvm {
@@ -44,7 +45,8 @@ class VPRecipeBuilder;
 class VPBuilder {
   VPBasicBlock *BB = nullptr;
   VPBasicBlock::iterator InsertPt = VPBasicBlock::iterator();
-  [[maybe_unused]] VPlan &Plan;
+  VPlan &Plan;
+  VPConstantFolder Folder;
 
   /// Insert \p VPI in BB at InsertPt if BB is set.
   template <typename T> T *tryInsertInstruction(T *R) {
@@ -174,17 +176,22 @@ class VPBuilder {
 
   VPValue *createNot(VPValue *Operand, DebugLoc DL = {},
                      const Twine &Name = "") {
+    if (auto *V = Folder.foldNot(Operand))
+      return Plan.getOrAddLiveIn(V);
     return createInstruction(VPInstruction::Not, {Operand}, DL, Name);
   }
 
   VPValue *createAnd(VPValue *LHS, VPValue *RHS, DebugLoc DL = {},
                      const Twine &Name = "") {
+    if (auto *V = Folder.foldAnd(LHS, RHS))
+      return Plan.getOrAddLiveIn(V);
     return createInstruction(Instruction::BinaryOps::And, {LHS, RHS}, DL, Name);
   }
 
   VPValue *createOr(VPValue *LHS, VPValue *RHS, DebugLoc DL = {},
                     const Twine &Name = "") {
-
+    if (auto *V = Folder.foldOr(LHS, RHS))
+      return Plan.getOrAddLiveIn(V);
     return tryInsertInstruction(new VPInstruction(
         Instruction::BinaryOps::Or, {LHS, RHS},
         VPRecipeWithIRFlags::DisjointFlagsTy(false), DL, Name));
@@ -192,6 +199,8 @@ class VPBuilder {
 
   VPValue *createLogicalAnd(VPValue *LHS, VPValue *RHS, DebugLoc DL = {},
                             const Twine &Name = "") {
+    if (auto *V = Folder.foldLogicalAnd(LHS, RHS))
+      return Plan.getOrAddLiveIn(V);
     return tryInsertInstruction(
         new VPInstruction(VPInstruction::LogicalAnd, {LHS, RHS}, DL, Name));
   }
@@ -199,6 +208,8 @@ class VPBuilder {
   VPValue *createSelect(VPValue *Cond, VPValue *TrueVal, VPValue *FalseVal,
                         DebugLoc DL = {}, const Twine &Name = "",
                         std::optional<FastMathFlags> FMFs = std::nullopt) {
+    if (auto *V = Folder.foldSelect(Cond, TrueVal, FalseVal))
+      return Plan.getOrAddLiveIn(V);
     auto *Select =
         FMFs ? new VPInstruction(Instruction::Select, {Cond, TrueVal, FalseVal},
                                  *FMFs, DL, Name)
@@ -214,17 +225,23 @@ class VPBuilder {
                       DebugLoc DL = {}, const Twine &Name = "") {
     assert(Pred >= CmpInst::FIRST_ICMP_PREDICATE &&
            Pred <= CmpInst::LAST_ICMP_PREDICATE && "invalid predicate");
+    if (auto *V = Folder.foldCmp(Pred, A, B))
+      return Plan.getOrAddLiveIn(V);
     return tryInsertInstruction(
         new VPInstruction(Instruction::ICmp, Pred, A, B, DL, Name));
   }
 
-  VPInstruction *createPtrAdd(VPValue *Ptr, VPValue *Offset, DebugLoc DL = {},
-                              const Twine &Name = "") {
+  VPValue *createPtrAdd(VPValue *Ptr, VPValue *Offset, DebugLoc DL = {},
+                        const Twine &Name = "") {
+    if (auto *V = Folder.foldPtrAdd(Ptr, Offset, GEPNoWrapFlags::none()))
+      return Plan.getOrAddLiveIn(V);
     return tryInsertInstruction(
         new VPInstruction(Ptr, Offset, GEPNoWrapFlags::none(), DL, Name));
   }
   VPValue *createInBoundsPtrAdd(VPValue *Ptr, VPValue *Offset, DebugLoc DL = {},
                                 const Twine &Name = "") {
+    if (auto *V = Folder.foldPtrAdd(Ptr, Offset, GEPNoWrapFlags::inBounds()))
+      return Plan.getOrAddLiveIn(V);
     return tryInsertInstruction(
         new VPInstruction(Ptr, Offset, GEPNoWrapFlags::inBounds(), DL, Name));
   }
@@ -240,14 +257,18 @@ class VPBuilder {
         new VPDerivedIVRecipe(Kind, FPBinOp, Start, Current, Step, Name));
   }
 
-  VPScalarCastRecipe *createScalarCast(Instruction::CastOps Opcode, VPValue *Op,
-                                       Type *ResultTy, DebugLoc DL) {
+  VPValue *createScalarCast(Instruction::CastOps Opcode, VPValue *Op,
+                            Type *ResultTy, DebugLoc DL) {
+    if (auto *V = Folder.foldCast(Opcode, Op, ResultTy))
+      return Plan.getOrAddLiveIn(V);
     return tryInsertInstruction(
         new VPScalarCastRecipe(Opcode, Op, ResultTy, DL));
   }
 
-  VPWidenCastRecipe *createWidenCast(Instruction::CastOps Opcode, VPValue *Op,
-                                     Type *ResultTy) {
+  VPValue *createWidenCast(Instruction::CastOps Opcode, VPValue *Op,
+                           Type *ResultTy) {
+    if (auto *V = Folder.foldCast(Opcode, Op, ResultTy))
+      return Plan.getOrAddLiveIn(V);
     return tryInsertInstruction(new VPWidenCastRecipe(Opcode, Op, ResultTy));
   }
 
diff --git a/llvm/lib/Transforms/Vectorize/VPlanConstantFolder.h b/llvm/lib/Transforms/Vectorize/VPlanConstantFolder.h
new file mode 100644
index 00000000000000..01e47e92afa5cf
--- /dev/null
+++ b/llvm/lib/Transforms/Vectorize/VPlanConstantFolder.h
@@ -0,0 +1,96 @@
+//===- VPlanConstantFolder.h - ConstantFolder for VPlan -------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "VPlanValue.h"
+#include "llvm/IR/ConstantFold.h"
+#include "llvm/IR/Constants.h"
+
+namespace llvm {
+class VPConstantFolder {
+private:
+  Constant *getIRConstant(VPValue *V) const {
+    return dyn_cast_or_null<Constant>(V->getUnderlyingValue());
+  }
+
+  Value *foldBinOp(Instruction::BinaryOps Opcode, VPValue *LHS,
+                   VPValue *RHS) const {
+    auto *LC = getIRConstant(LHS);
+    auto *RC = getIRConstant(RHS);
+    if (LC && RC) {
+      if (ConstantExpr::isDesirableBinOp(Opcode))
+        return ConstantExpr::get(Opcode, LC, RC);
+      return ConstantFoldBinaryInstruction(Opcode, LC, RC);
+    }
+    return nullptr;
+  }
+
+public:
+  Value *foldAnd(VPValue *LHS, VPValue *RHS) const {
+    return foldBinOp(Instruction::BinaryOps::And, LHS, RHS);
+  }
+
+  Value *foldOr(VPValue *LHS, VPValue *RHS) const {
+    return foldBinOp(Instruction::BinaryOps::Or, LHS, RHS);
+  }
+
+  Value *foldNot(VPValue *Op) const {
+    auto *C = getIRConstant(Op);
+    if (C)
+      return ConstantExpr::get(Instruction::BinaryOps::Xor, C,
+                               Constant::getAllOnesValue(C->getType()));
+    return nullptr;
+  }
+
+  Value *foldLogicalAnd(VPValue *LHS, VPValue *RHS) const {
+    auto *LC = getIRConstant(LHS);
+    auto *RC = getIRConstant(RHS);
+    if (LC && RC)
+      return ConstantFoldSelectInstruction(
+          LC, RC, ConstantInt::getNullValue(RC->getType()));
+    return nullptr;
+  }
+
+  Value *foldSelect(VPValue *Cond, VPValue *TrueVal, VPValue *FalseVal) const {
+    auto *CC = getIRConstant(Cond);
+    auto *TV = getIRConstant(TrueVal);
+    auto *FV = getIRConstant(FalseVal);
+    if (CC && TV && FV)
+      return ConstantFoldSelectInstruction(CC, TV, FV);
+    return nullptr;
+  }
+
+  Value *foldCmp(CmpInst::Predicate Pred, VPValue *LHS, VPValue *RHS) const {
+    auto *LC = getIRConstant(LHS);
+    auto *RC = getIRConstant(RHS);
+    if (LC && RC)
+      return ConstantFoldCompareInstruction(Pred, LC, RC);
+    return nullptr;
+  }
+
+  Value *foldPtrAdd(VPValue *Base, VPValue *Offset, GEPNoWrapFlags NW) const {
+    auto *BC = getIRConstant(Base);
+    auto *OC = getIRConstant(Offset);
+    if (BC && OC) {
+      auto &Ctx = BC->getType()->getContext();
+      return ConstantExpr::getGetElementPtr(Type::getInt8Ty(Ctx), BC, OC, NW);
+    }
+    return nullptr;
+  }
+
+  Value *foldCast(Instruction::CastOps Opcode, VPValue *Op,
+                  Type *DestTy) const {
+    auto *C = getIRConstant(Op);
+    if (C) {
+      if (ConstantExpr::isDesirableCastOp(Opcode))
+        return ConstantExpr::getCast(Opcode, C, DestTy);
+      return ConstantFoldCastInstruction(Opcode, C, DestTy);
+    }
+    return nullptr;
+  }
+};
+} // namespace llvm
diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index bf95b62474150c..5e0d1efb959030 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -532,8 +532,8 @@ createScalarIVSteps(VPlan &Plan, InductionDescriptor::InductionKind Kind,
                     VPBuilder &Builder) {
   VPBasicBlock *HeaderVPBB = Plan.getVectorLoopRegion()->getEntryBasicBlock();
   VPCanonicalIVPHIRecipe *CanonicalIV = Plan.getCanonicalIV();
-  VPSingleDefRecipe *BaseIV = Builder.createDerivedIV(
-      Kind, FPBinOp, StartV, CanonicalIV, Step, "offset.idx");
+  VPValue *BaseIV = Builder.createDerivedIV(Kind, FPBinOp, StartV, CanonicalIV,
+                                            Step, "offset.idx");
 
   // Truncate base induction if needed.
   Type *CanonicalIVType = CanonicalIV->getScalarType();
diff --git a/llvm/test/Transforms/LoopVectorize/X86/replicate-recipe-with-only-first-lane-used.ll b/llvm/test/Transforms/LoopVectorize/X86/replicate-recipe-with-only-first-lane-used.ll
index e6c9ce3381f73f..141ef6ec0b97e4 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/replicate-recipe-with-only-first-lane-used.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/replicate-recipe-with-only-first-lane-used.ll
@@ -12,56 +12,10 @@ define void @replicate_udiv_with_only_first_lane_used(i32 %x, ptr %dst, i64 %d)
 ; CHECK-NEXT:    [[C:%.*]] = icmp eq i32 [[X]], 10
 ; CHECK-NEXT:    br i1 false, label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
 ; CHECK:       [[VECTOR_PH]]:
+; CHECK-NEXT:    [[TMP11:%.*]] = getelementptr i16, ptr [[DST]], i64 0
 ; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
 ; CHECK:       [[VECTOR_BODY]]:
-; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[PRED_UDIV_CONTINUE14:.*]] ]
-; CHECK-NEXT:    br i1 false, label %[[PRED_UDIV_IF:.*]], label %[[PRED_UDIV_CONTINUE:.*]]
-; CHECK:       [[PRED_UDIV_IF]]:
-; CHECK-NEXT:    [[TMP0:%.*]] = udiv i64 99, [[D]]
-; CHECK-NEXT:    br label %[[PRED_UDIV_CONTINUE]]
-; CHECK:       [[PRED_UDIV_CONTINUE]]:
-; CHECK-NEXT:    [[TMP1:%.*]] = phi i64 [ poison, %[[VECTOR_BODY]] ], [ [[TMP0]], %[[PRED_UDIV_IF]] ]
-; CHECK-NEXT:    br i1 false, label %[[PRED_UDIV_IF1:.*]], label %[[PRED_UDIV_CONTINUE2:.*]]
-; CHECK:       [[PRED_UDIV_IF1]]:
-; CHECK-NEXT:    [[TMP2:%.*]] = udiv i64 99, [[D]]
-; CHECK-NEXT:    br label %[[PRED_UDIV_CONTINUE2]]
-; CHECK:       [[PRED_UDIV_CONTINUE2]]:
-; CHECK-NEXT:    br i1 false, label %[[PRED_UDIV_IF3:.*]], label %[[PRED_UDIV_CONTINUE4:.*]]
-; CHECK:       [[PRED_UDIV_IF3]]:
-; CHECK-NEXT:    [[TMP3:%.*]] = udiv i64 99, [[D]]
-; CHECK-NEXT:    br label %[[PRED_UDIV_CONTINUE4]]
-; CHECK:       [[PRED_UDIV_CONTINUE4]]:
-; CHECK-NEXT:    br i1 false, label %[[PRED_UDIV_IF5:.*]], label %[[PRED_UDIV_CONTINUE6:.*]]
-; CHECK:       [[PRED_UDIV_IF5]]:
-; CHECK-NEXT:    [[TMP4:%.*]] = udiv i64 99, [[D]]
-; CHECK-NEXT:    br label %[[PRED_UDIV_CONTINUE6]]
-; CHECK:       [[PRED_UDIV_CONTINUE6]]:
-; CHECK-NEXT:    br i1 false, label %[[PRED_UDIV_IF7:.*]], label %[[PRED_UDIV_CONTINUE8:.*]]
-; CHECK:       [[PRED_UDIV_IF7]]:
-; CHECK-NEXT:    [[TMP5:%.*]] = udiv i64 99, [[D]]
-; CHECK-NEXT:    br label %[[PRED_UDIV_CONTINUE8]]
-; CHECK:       [[PRED_UDIV_CONTINUE8]]:
-; CHECK-NEXT:    [[TMP6:%.*]] = phi i64 [ poison, %[[PRED_UDIV_CONTINUE6]] ], [ [[TMP5]], %[[PRED_UDIV_IF7]] ]
-; CHECK-NEXT:    br i1 false, label %[[PRED_UDIV_IF9:.*]], label %[[PRED_UDIV_CONTINUE10:.*]]
-; CHECK:       [[PRED_UDIV_IF9]]:
-; CHECK-NEXT:    [[TMP7:%.*]] = udiv i64 99, [[D]]
-; CHECK-NEXT:    br label %[[PRED_UDIV_CONTINUE10]]
-; CHECK:       [[PRED_UDIV_CONTINUE10]]:
-; CHECK-NEXT:    br i1 false, label %[[PRED_UDIV_IF11:.*]], label %[[PRED_UDIV_CONTINUE12:.*]]
-; CHECK:       [[PRED_UDIV_IF11]]:
-; CHECK-NEXT:    [[TMP8:%.*]] = udiv i64 99, [[D]]
-; CHECK-NEXT:    br label %[[PRED_UDIV_CONTINUE12]]
-; CHECK:       [[PRED_UDIV_CONTINUE12]]:
-; CHECK-NEXT:    br i1 false, label %[[PRED_UDIV_IF13:.*]], label %[[PRED_UDIV_CONTINUE14]]
-; CHECK:       [[PRED_UDIV_IF13]]:
-; CHECK-NEXT:    [[TMP9:%.*]] = udiv i64 99, [[D]]
-; CHECK-NEXT:    br label %[[PRED_UDIV_CONTINUE14]]
-; CHECK:       [[PRED_UDIV_CONTINUE14]]:
-; CHECK-NEXT:    [[PREDPHI:%.*]] = select i1 true, i64 0, i64 [[TMP1]]
-; CHECK-NEXT:    [[PREDPHI15:%.*]] = select i1 true, i64 0, i64 [[TMP6]]
-; CHECK-NEXT:    [[TMP10:%.*]] = getelementptr i16, ptr [[DST]], i64 [[PREDPHI]]
-; CHECK-NEXT:    [[TMP11:%.*]] = getelementptr i16, ptr [[DST]], i64 [[PREDPHI15]]
-; CHECK-NEXT:    store i16 0, ptr [[TMP10]], align 2
+; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
 ; CHECK-NEXT:    store i16 0, ptr [[TMP11]], align 2
 ; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 8
 ; CHECK-NEXT:    [[TMP12:%.*]] = icmp eq i64 [[INDEX_NEXT]], 96
diff --git a/llvm/test/Transforms/LoopVectorize/interleave-and-scalarize-only.ll b/llvm/test/Transforms/LoopVectorize/interleave-and-scalarize-only.ll
index c3164762e81300..c294ec11b906d8 100644
--- a/llvm/test/Transforms/LoopVectorize/interleave-and-scalarize-only.ll
+++ b/llvm/test/Transforms/LoopVectorize/interleave-and-scalarize-only.ll
@@ -202,15 +202,14 @@ exit:
 ; DBG-NEXT: Successor(s): vector.ph
 ; DBG-EMPTY:
 ; DBG-NEXT: vector.ph:
-; DBG-NEXT:   SCALAR-CAST vp<[[CAST:%.+]]> = trunc ir<1> to i32
 ; DBG-NEXT: Successor(s): vector loop
 ; DBG-EMPTY:
 ; DBG-NEXT: <x1> vector loop: {
 ; DBG-NEXT:   vector.body:
-; DBG-NEXT:     EMIT vp<[[CAN_IV:%.+]]> = CANONICAL-INDUCTION
+; DBG-NEXT:     EMIT vp<[[CAN_IV:%.+]]> = CANONICAL-INDUCTION ir<0>, vp<[[INDEX_NEXT:%.*]]>
 ; DBG-NEXT:     FIRST-ORDER-RECURRENCE-PHI ir<%for> = phi ir<0>, vp<[[SCALAR_STEPS:.+]]>
 ; DBG-NEXT:     SCALAR-CAST vp<[[TRUNC_IV:%.+]]> = trunc vp<[[CAN_IV]]> to i32
-; DBG-NEXT:     vp<[[SCALAR_STEPS]]> = SCALAR-STEPS vp<[[TRUNC_IV]]>, vp<[[CAST]]>
+; DBG-NEXT:     vp<[[SCALAR_STEPS]]> = SCALAR-STEPS vp<[[TRUNC_IV]]>, ir<1>
 ; DBG-NEXT:     EMIT vp<[[SPLICE:%.+]]> = first-order splice ir<%for>, vp<[[SCALAR_STEPS]]>
 ; DBG-NEXT:     CLONE store vp<[[SPLICE]]>, ir<%dst>
 ; DBG-NEXT:     EMIT vp<[[IV_INC:%.+]]> = add nuw vp<[[CAN_IV]]>, vp<[[VFxUF]]>



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