[VPlan] VPlan version of InterleavedAccessInfo.

This patch turns InterleaveGroup into a template with the instruction type
being a template parameter. It also adds a VPInterleavedAccessInfo class, which
only contains a mapping from VPInstructions to their respective InterleaveGroup.
As we do not have access to scalar evolution in VPlan, we can re-use
convert InterleavedAccessInfo to VPInterleavedAccess info.


Reviewers: Ayal, mssimpso, hfinkel, dcaballe, rengolin, mkuper, hsaito

Reviewed By: rengolin

Differential Revision: https://reviews.llvm.org/D49489

llvm-svn: 346758

Author: fhahn

llvm/include/llvm/Analysis/VectorUtils.h

@@ -24,7 +24,7 @@ namespace llvm {
 template <typename T> class ArrayRef;
 class DemandedBits;
 class GetElementPtrInst;
-class InterleaveGroup; 
+template <typename InstTy> class InterleaveGroup;
 class Loop;
 class ScalarEvolution;
 class TargetTransformInfo;
@@ -138,7 +138,7 @@ Instruction *propagateMetadata(Instruction *I, ArrayRef<Value *> VL);
 /// create[*]Mask() utilities which create a shuffle mask (mask that
 /// consists of indices).
 Constant *createBitMaskForGaps(IRBuilder<> &Builder, unsigned VF,
-                               const InterleaveGroup &Group);
+                               const InterleaveGroup<Instruction> &Group);
 
 /// Create a mask with replicated elements.
 ///
@@ -233,9 +233,12 @@ Value *concatenateVectors(IRBuilder<> &Builder, ArrayRef<Value *> Vecs);
 ///
 /// Note: the interleaved load group could have gaps (missing members), but
 /// the interleaved store group doesn't allow gaps.
-class InterleaveGroup {
+template <typename InstTy> class InterleaveGroup {
 public:
-  InterleaveGroup(Instruction *Instr, int Stride, unsigned Align)
+  InterleaveGroup(unsigned Factor, bool Reverse, unsigned Align)
+      : Factor(Factor), Reverse(Reverse), Align(Align), InsertPos(nullptr) {}
+
+  InterleaveGroup(InstTy *Instr, int Stride, unsigned Align)
       : Align(Align), InsertPos(Instr) {
     assert(Align && "The alignment should be non-zero");
 
@@ -256,7 +259,7 @@ class InterleaveGroup {
   /// negative if it is the new leader.
   ///
   /// \returns false if the instruction doesn't belong to the group.
-  bool insertMember(Instruction *Instr, int Index, unsigned NewAlign) {
+  bool insertMember(InstTy *Instr, int Index, unsigned NewAlign) {
     assert(NewAlign && "The new member's alignment should be non-zero");
 
     int Key = Index + SmallestKey;
@@ -288,7 +291,7 @@ class InterleaveGroup {
   /// Get the member with the given index \p Index
   ///
   /// \returns nullptr if contains no such member.
-  Instruction *getMember(unsigned Index) const {
+  InstTy *getMember(unsigned Index) const {
     int Key = SmallestKey + Index;
     auto Member = Members.find(Key);
     if (Member == Members.end())
@@ -299,29 +302,25 @@ class InterleaveGroup {
 
   /// Get the index for the given member. Unlike the key in the member
   /// map, the index starts from 0.
-  unsigned getIndex(Instruction *Instr) const {
-    for (auto I : Members)
+  unsigned getIndex(const InstTy *Instr) const {
+    for (auto I : Members) {
       if (I.second == Instr)
         return I.first - SmallestKey;
+    }
 
     llvm_unreachable("InterleaveGroup contains no such member");
   }
 
-  Instruction *getInsertPos() const { return InsertPos; }
-  void setInsertPos(Instruction *Inst) { InsertPos = Inst; }
+  InstTy *getInsertPos() const { return InsertPos; }
+  void setInsertPos(InstTy *Inst) { InsertPos = Inst; }
 
   /// Add metadata (e.g. alias info) from the instructions in this group to \p
   /// NewInst.
   ///
   /// FIXME: this function currently does not add noalias metadata a'la
   /// addNewMedata.  To do that we need to compute the intersection of the
   /// noalias info from all members.
-  void addMetadata(Instruction *NewInst) const {
-    SmallVector<Value *, 4> VL;
-    std::transform(Members.begin(), Members.end(), std::back_inserter(VL),
-                   [](std::pair<int, Instruction *> p) { return p.second; });
-    propagateMetadata(NewInst, VL);
-  }
+  void addMetadata(InstTy *NewInst) const;
 
   /// Returns true if this Group requires a scalar iteration to handle gaps.
   bool requiresScalarEpilogue() const {
@@ -344,7 +343,7 @@ class InterleaveGroup {
   unsigned Factor; // Interleave Factor.
   bool Reverse;
   unsigned Align;
-  DenseMap<int, Instruction *> Members;
+  DenseMap<int, InstTy *> Members;
   int SmallestKey = 0;
   int LargestKey = 0;
 
@@ -359,7 +358,7 @@ class InterleaveGroup {
   //      store i32 %even
   //      %odd = add i32               // Def of %odd
   //      store i32 %odd               // Insert Position
-  Instruction *InsertPos;
+  InstTy *InsertPos;
 };
 
 /// Drive the analysis of interleaved memory accesses in the loop.
@@ -390,7 +389,7 @@ class InterleavedAccessInfo {
   /// formation for predicated accesses, we may be able to relax this limitation
   /// in the future once we handle more complicated blocks.
   void reset() {
-    SmallPtrSet<InterleaveGroup *, 4> DelSet;
+    SmallPtrSet<InterleaveGroup<Instruction> *, 4> DelSet;
     // Avoid releasing a pointer twice.
     for (auto &I : InterleaveGroupMap)
       DelSet.insert(I.second);
@@ -409,11 +408,16 @@ class InterleavedAccessInfo {
   /// Get the interleave group that \p Instr belongs to.
   ///
   /// \returns nullptr if doesn't have such group.
-  InterleaveGroup *getInterleaveGroup(Instruction *Instr) const {
-    auto Group = InterleaveGroupMap.find(Instr);
-    if (Group == InterleaveGroupMap.end())
-      return nullptr;
-    return Group->second;
+  InterleaveGroup<Instruction> *
+  getInterleaveGroup(const Instruction *Instr) const {
+    if (InterleaveGroupMap.count(Instr))
+      return InterleaveGroupMap.find(Instr)->second;
+    return nullptr;
+  }
+
+  iterator_range<SmallPtrSetIterator<llvm::InterleaveGroup<Instruction> *>>
+  getInterleaveGroups() {
+    return make_range(InterleaveGroups.begin(), InterleaveGroups.end());
   }
 
   /// Returns true if an interleaved group that may access memory
@@ -443,7 +447,9 @@ class InterleavedAccessInfo {
   bool RequiresScalarEpilogue = false;
 
   /// Holds the relationships between the members and the interleave group.
-  DenseMap<Instruction *, InterleaveGroup *> InterleaveGroupMap;
+  DenseMap<Instruction *, InterleaveGroup<Instruction> *> InterleaveGroupMap;
+
+  SmallPtrSet<InterleaveGroup<Instruction> *, 4> InterleaveGroups;
 
   /// Holds dependences among the memory accesses in the loop. It maps a source
   /// access to a set of dependent sink accesses.
@@ -476,19 +482,23 @@ class InterleavedAccessInfo {
   /// stride \p Stride and alignment \p Align.
   ///
   /// \returns the newly created interleave group.
-  InterleaveGroup *createInterleaveGroup(Instruction *Instr, int Stride,
-                                         unsigned Align) {
-    assert(!isInterleaved(Instr) && "Already in an interleaved access group");
-    InterleaveGroupMap[Instr] = new InterleaveGroup(Instr, Stride, Align);
+  InterleaveGroup<Instruction> *
+  createInterleaveGroup(Instruction *Instr, int Stride, unsigned Align) {
+    assert(!InterleaveGroupMap.count(Instr) &&
+           "Already in an interleaved access group");
+    InterleaveGroupMap[Instr] =
+        new InterleaveGroup<Instruction>(Instr, Stride, Align);
+    InterleaveGroups.insert(InterleaveGroupMap[Instr]);
     return InterleaveGroupMap[Instr];
   }
 
   /// Release the group and remove all the relationships.
-  void releaseGroup(InterleaveGroup *Group) {
+  void releaseGroup(InterleaveGroup<Instruction> *Group) {
     for (unsigned i = 0; i < Group->getFactor(); i++)
       if (Instruction *Member = Group->getMember(i))
         InterleaveGroupMap.erase(Member);
 
+    InterleaveGroups.erase(Group);
     delete Group;
   }
 

llvm/lib/Analysis/VectorUtils.cpp

@@ -505,8 +505,9 @@ Instruction *llvm::propagateMetadata(Instruction *Inst, ArrayRef<Value *> VL) {
   return Inst;
 }
 
-Constant *llvm::createBitMaskForGaps(IRBuilder<> &Builder, unsigned VF,
-                                           const InterleaveGroup &Group) {
+Constant *
+llvm::createBitMaskForGaps(IRBuilder<> &Builder, unsigned VF,
+                           const InterleaveGroup<Instruction> &Group) {
   // All 1's means mask is not needed.
   if (Group.getNumMembers() == Group.getFactor())
     return nullptr;
@@ -720,9 +721,9 @@ void InterleavedAccessInfo::analyzeInterleaving(
   collectDependences();
 
   // Holds all interleaved store groups temporarily.
-  SmallSetVector<InterleaveGroup *, 4> StoreGroups;
+  SmallSetVector<InterleaveGroup<Instruction> *, 4> StoreGroups;
   // Holds all interleaved load groups temporarily.
-  SmallSetVector<InterleaveGroup *, 4> LoadGroups;
+  SmallSetVector<InterleaveGroup<Instruction> *, 4> LoadGroups;
 
   // Search in bottom-up program order for pairs of accesses (A and B) that can
   // form interleaved load or store groups. In the algorithm below, access A
@@ -744,7 +745,7 @@ void InterleavedAccessInfo::analyzeInterleaving(
     // Initialize a group for B if it has an allowable stride. Even if we don't
     // create a group for B, we continue with the bottom-up algorithm to ensure
     // we don't break any of B's dependences.
-    InterleaveGroup *Group = nullptr;
+    InterleaveGroup<Instruction> *Group = nullptr;
     if (isStrided(DesB.Stride) && 
         (!isPredicated(B->getParent()) || EnablePredicatedInterleavedMemAccesses)) {
       Group = getInterleaveGroup(B);
@@ -789,7 +790,7 @@ void InterleavedAccessInfo::analyzeInterleaving(
         // illegal code motion. A will then be free to form another group with
         // instructions that precede it.
         if (isInterleaved(A)) {
-          InterleaveGroup *StoreGroup = getInterleaveGroup(A);
+          InterleaveGroup<Instruction> *StoreGroup = getInterleaveGroup(A);
           StoreGroups.remove(StoreGroup);
           releaseGroup(StoreGroup);
         }
@@ -868,7 +869,7 @@ void InterleavedAccessInfo::analyzeInterleaving(
   }   // Iteration over B accesses.
 
   // Remove interleaved store groups with gaps.
-  for (InterleaveGroup *Group : StoreGroups)
+  for (auto *Group : StoreGroups)
     if (Group->getNumMembers() != Group->getFactor()) {
       LLVM_DEBUG(
           dbgs() << "LV: Invalidate candidate interleaved store group due "
@@ -889,7 +890,7 @@ void InterleavedAccessInfo::analyzeInterleaving(
   // This means that we can forcefully peel the loop in order to only have to
   // check the first pointer for no-wrap. When we'll change to use Assume=true
   // we'll only need at most one runtime check per interleaved group.
-  for (InterleaveGroup *Group : LoadGroups) {
+  for (auto *Group : LoadGroups) {
     // Case 1: A full group. Can Skip the checks; For full groups, if the wide
     // load would wrap around the address space we would do a memory access at
     // nullptr even without the transformation.
@@ -947,9 +948,9 @@ void InterleavedAccessInfo::invalidateGroupsRequiringScalarEpilogue() {
     return;
 
   // Avoid releasing a Group twice.
-  SmallPtrSet<InterleaveGroup *, 4> DelSet;
+  SmallPtrSet<InterleaveGroup<Instruction> *, 4> DelSet;
   for (auto &I : InterleaveGroupMap) {
-    InterleaveGroup *Group = I.second;
+    InterleaveGroup<Instruction> *Group = I.second;
     if (Group->requiresScalarEpilogue())
       DelSet.insert(Group);
   }
@@ -964,3 +965,16 @@ void InterleavedAccessInfo::invalidateGroupsRequiringScalarEpilogue() {
 
   RequiresScalarEpilogue = false;
 }
+
+template <>
+void InterleaveGroup<Instruction>::addMetadata(Instruction *NewInst) const {
+  SmallVector<Value *, 4> VL;
+  std::transform(Members.begin(), Members.end(), std::back_inserter(VL),
+                 [](std::pair<int, Instruction *> p) { return p.second; });
+  propagateMetadata(NewInst, VL);
+}
+
+template <typename InstT>
+void InterleaveGroup<InstT>::addMetadata(InstT *NewInst) const {
+  llvm_unreachable("addMetadata can only be used for Instruction");
+}

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -976,7 +976,7 @@ class LoopVectorizationCostModel {
 
   /// Save vectorization decision \p W and \p Cost taken by the cost model for
   /// interleaving group \p Grp and vector width \p VF.
-  void setWideningDecision(const InterleaveGroup *Grp, unsigned VF,
+  void setWideningDecision(const InterleaveGroup<Instruction> *Grp, unsigned VF,
                            InstWidening W, unsigned Cost) {
     assert(VF >= 2 && "Expected VF >=2");
     /// Broadcast this decicion to all instructions inside the group.
@@ -1131,7 +1131,8 @@ class LoopVectorizationCostModel {
   }
 
   /// Get the interleaved access group that \p Instr belongs to.
-  const InterleaveGroup *getInterleavedAccessGroup(Instruction *Instr) {
+  const InterleaveGroup<Instruction> *
+  getInterleavedAccessGroup(Instruction *Instr) {
     return InterleaveInfo.getInterleaveGroup(Instr);
   }
 
@@ -1994,7 +1995,8 @@ static bool useMaskedInterleavedAccesses(const TargetTransformInfo &TTI) {
 //   store <12 x i32> %interleaved.vec              ; Write 4 tuples of R,G,B
 void InnerLoopVectorizer::vectorizeInterleaveGroup(Instruction *Instr,
                                                    VectorParts *BlockInMask) {
-  const InterleaveGroup *Group = Cost->getInterleavedAccessGroup(Instr);
+  const InterleaveGroup<Instruction> *Group =
+      Cost->getInterleavedAccessGroup(Instr);
   assert(Group && "Fail to get an interleaved access group.");
 
   // Skip if current instruction is not the insert position.
@@ -6377,7 +6379,7 @@ VPValue *VPRecipeBuilder::createBlockInMask(BasicBlock *BB, VPlanPtr &Plan) {
 VPInterleaveRecipe *VPRecipeBuilder::tryToInterleaveMemory(Instruction *I,
                                                            VFRange &Range,
                                                            VPlanPtr &Plan) {
-  const InterleaveGroup *IG = CM.getInterleavedAccessGroup(I);
+  const InterleaveGroup<Instruction> *IG = CM.getInterleavedAccessGroup(I);
   if (!IG)
     return nullptr;
 
@@ -6793,7 +6795,8 @@ LoopVectorizationPlanner::buildVPlanWithVPRecipes(
 
       // I is a member of an InterleaveGroup for Range.Start. If it's an adjunct
       // member of the IG, do not construct any Recipe for it.
-      const InterleaveGroup *IG = CM.getInterleavedAccessGroup(Instr);
+      const InterleaveGroup<Instruction> *IG =
+          CM.getInterleavedAccessGroup(Instr);
       if (IG && Instr != IG->getInsertPos() &&
           Range.Start >= 2 && // Query is illegal for VF == 1
           CM.getWideningDecision(Instr, Range.Start) ==

llvm/lib/Transforms/Vectorize/VPlan.cpp

@@ -680,3 +680,48 @@ void VPWidenMemoryInstructionRecipe::print(raw_ostream &O,
 }
 
 template void DomTreeBuilder::Calculate<VPDominatorTree>(VPDominatorTree &DT);
+
+void VPInterleavedAccessInfo::visitRegion(VPRegionBlock *Region,
+                                          Old2NewTy &Old2New,
+                                          InterleavedAccessInfo &IAI) {
+  ReversePostOrderTraversal<VPBlockBase *> RPOT(Region->getEntry());
+  for (VPBlockBase *Base : RPOT) {
+    visitBlock(Base, Old2New, IAI);
+  }
+}
+
+void VPInterleavedAccessInfo::visitBlock(VPBlockBase *Block, Old2NewTy &Old2New,
+                                         InterleavedAccessInfo &IAI) {
+  if (VPBasicBlock *VPBB = dyn_cast<VPBasicBlock>(Block)) {
+    for (VPRecipeBase &VPI : *VPBB) {
+      assert(isa<VPInstruction>(&VPI) && "Can only handle VPInstructions");
+      auto *VPInst = cast<VPInstruction>(&VPI);
+      auto *Inst = cast<Instruction>(VPInst->getUnderlyingValue());
+      auto *IG = IAI.getInterleaveGroup(Inst);
+      if (!IG)
+        continue;
+
+      auto NewIGIter = Old2New.find(IG);
+      if (NewIGIter == Old2New.end())
+        Old2New[IG] = new InterleaveGroup<VPInstruction>(
+            IG->getFactor(), IG->isReverse(), IG->getAlignment());
+
+      if (Inst == IG->getInsertPos())
+        Old2New[IG]->setInsertPos(VPInst);
+
+      InterleaveGroupMap[VPInst] = Old2New[IG];
+      InterleaveGroupMap[VPInst]->insertMember(
+          VPInst, IG->getIndex(Inst),
+          IG->isReverse() ? (-1) * int(IG->getFactor()) : IG->getFactor());
+    }
+  } else if (VPRegionBlock *Region = dyn_cast<VPRegionBlock>(Block))
+    visitRegion(Region, Old2New, IAI);
+  else
+    llvm_unreachable("Unsupported kind of VPBlock.");
+}
+
+VPInterleavedAccessInfo::VPInterleavedAccessInfo(VPlan &Plan,
+                                                 InterleavedAccessInfo &IAI) {
+  Old2NewTy Old2New;
+  visitRegion(cast<VPRegionBlock>(Plan.getEntry()), Old2New, IAI);
+}