[TSAR, Memory] Fix filling of sets Def, MayDef and Use with memory locations of kind 'Hint'.

Author: yukatan1701

include/tsar/Analysis/Memory/DefinedMemory.h

@@ -95,8 +95,8 @@ class DefUseSet {
 
   /// Set of data flow nodes with which memory locations from the 
   /// ExplicitAccesses set are associated.
-  typedef llvm::DenseMap<const llvm::Value *, llvm::DenseSet<const DFNode *>>
-      ExplicitNodeMap;
+  typedef llvm::SmallDenseMap<const llvm::Value *,
+      llvm::SmallDenseSet<const DFNode *>> ExplicitNodeMap;
 
   /// Returns set of the must defined locations.
   const LocationSet & getDefs() const { return mDefs; }
@@ -392,18 +392,26 @@ class DefUseSet {
         .second;
   }
 
-  /// TODO: description
-  void addExplicitAccessNode(const llvm::Value *Ptr, const DFNode *N) {
-    assert(Ptr && "Location pointer must not be null!");
-    mCollapsableExplicitAccesses.try_emplace(Ptr).first->second.insert(N);
+  /// Inserts a data flow node associated with a collapsable explicit access
+  /// ExplLoc. ColLoc is a collapsed memory location created from the ExplLoc. 
+  void addNodeOfCollapsableExplicitAccess(
+      const MemoryLocationRange &ExplLoc,
+      const MemoryLocationRange &ColLoc,
+      const DFNode *N) {
+    assert(ExplLoc.Ptr && "Location pointer must not be null!");
+    assert(ColLoc.Kind == MemoryLocationRange::LocKind::Collapsed &&
+        "Location must be of a `collapsed` kind!");
+    mCollapsableExplicitAccesses.try_emplace(ExplLoc.Ptr).first->second.insert(N);
   }
 
-  /// TODO: description
+  /// Returns a map of collapsable explicit accesses with associated data flow
+  /// nodes.
   const ExplicitNodeMap & getCollapsableExplicitAccesses() const {
     return mCollapsableExplicitAccesses;
   }
 
-  /// TODO: description
+  /// Specifies that there are a collapsable explicit access to all collapsable 
+  /// explicit accesses from a specified map.
   void addCollapsableExplicitAccesses(const ExplicitNodeMap &ENM) {
     for (auto Itr = ENM.begin(); Itr != ENM.end(); ++Itr) {
       auto &NodeList = Itr->second;
@@ -412,10 +420,11 @@ class DefUseSet {
     }
   }
 
-  /// TODO: description
-  const llvm::DenseSet<const DFNode *> *
-  getCollapExpAccessNodes(const llvm::Value *Ptr) const {
-    auto Itr = mCollapsableExplicitAccesses.find(Ptr);
+  /// Returns a pointer to a set of data flow nodes associated with the memory 
+  /// location Loc if it is collabsable. Returns `nullptr` otherwise.
+  const llvm::SmallDenseSet<const DFNode *> *
+  getNodesOfCollapsableExplicitAccess(const MemoryLocationRange &Loc) const {
+    auto Itr = mCollapsableExplicitAccesses.find(Loc.Ptr);
     return Itr == mCollapsableExplicitAccesses.end() ? nullptr : &Itr->second;
   }
 

lib/Analysis/Memory/DefinedMemory.cpp

@@ -385,15 +385,6 @@ std::pair<MemoryLocationRange, bool> aggregate(
         break;
       }
       unsigned int TripCount = 0;
-      /*if (C->getLoop()->getLoopLatch() == C->getLoop()->getExitingBlock()) {
-        LLVM_DEBUG(dbgs() << "[AGGREGATE] Node kind: Latch and Exiting.\n"); 
-        TripCount = SE->getSmallConstantTripCount(C->getLoop());
-      } else {
-        LLVM_DEBUG(dbgs() << "[AGGREGATE] Node kind: Latch or Exiting.\n"); 
-        auto BTC = SE->getBackedgeTakenCount(C->getLoop());
-        if (isa<SCEVConstant>(BTC))
-          TripCount = cast<SCEVConstant>(BTC)->getAPInt().getZExtValue();
-      }*/
       if (C->getLoop()->getLoopLatch() == C->getLoop()->getExitingBlock()) {
         LLVM_DEBUG(dbgs() << "[AGGREGATE] Node kind: Latch and Exiting.\n"); 
         TripCount = SE->getSmallConstantTripCount(C->getLoop());
@@ -524,7 +515,8 @@ std::pair<MemoryLocationRange, bool> aggregate(
             getSExtValue() >= DimInfo.DimSize && DimensionN != 0 && N != nullptr) {
         auto End = cast<SCEVConstant>(DimInfo.End)->getAPInt().
             getSExtValue();
-        LLVM_DEBUG(dbgs() << "[AGGREGATE] Array index out of bounds. End = " << End << ", DimSize = " << DimInfo.DimSize << "\n");
+        LLVM_DEBUG(dbgs() << "[AGGREGATE] Array index out of bounds. End = " <<
+            End << ", DimSize = " << DimInfo.DimSize << "\n");
         break;
       }
       ResLoc.DimList.push_back(DimInfo);
@@ -891,7 +883,7 @@ void DataFlowTraits<ReachDFFwk*>::initialize(
             DU->addExplicitAccess(ALoc);
             auto ColLoc = aggregate(nullptr, nullptr, ALoc, DFF).first;
             if (ColLoc.Kind == MemoryLocationRange::LocKind::Collapsed) {
-              DU->addExplicitAccessNode(ALoc.Ptr, N);
+              DU->addNodeOfCollapsableExplicitAccess(ALoc, ColLoc, N);
             }
           }
         }
@@ -1114,22 +1106,6 @@ void ReachDFFwk::collapse(DFRegion *R) {
       LLVM_DEBUG(printLocInfo("[COLLAPSE] Collapse Use location: ", Loc));
       distribute(aggregate(R, N, Loc, this), Loc, OwnUses, OtherUses);
     }
-    /*LLVM_DEBUG(
-      dbgs() << "[COLLAPSE] OwnUses:\n";
-      for (auto &Loc : OwnUses)
-        printLocationSource(dbgs(), Loc, &getDomTree(), true); dbgs() << "\n";
-      dbgs() << "[COLLAPSE] OtherUses:\n";
-      for (auto &Pair : OtherUses) {
-        printLocationSource(dbgs(), Pair.first, &getDomTree(), true); dbgs() << "\n";
-        printLocationSource(dbgs(), Pair.second, &getDomTree(), true); dbgs() << "\n";
-      }
-    );
-    OwnUses.clarify(OtherUses);
-    LLVM_DEBUG(
-      dbgs() << "[COLLAPSE] OwnUses after clarify:\n";
-      for (auto &Loc : OwnUses)
-        printLocationSource(dbgs(), Loc, &getDomTree(), true); dbgs() << "\n";
-    );*/
     for (auto &Loc : OwnUses) {
       SmallVector<MemoryLocationRange, 4> UseDiff;
       if (MustReachIn.subtractFrom(Loc, UseDiff)) {
@@ -1252,10 +1228,13 @@ void ReachDFFwk::collapse(DFRegion *R) {
             EM = EM->getTopLevelParent();
     }
     LLVM_DEBUG(printLocInfo("[COLLAPSE] Collapse Explicit Access: ", Loc));
-    auto *DFNS = DefUse->getCollapExpAccessNodes(Loc.Ptr);
-    if (!DFNS)
-      continue;
-    for (auto *N : *DFNS) {
+    auto *DFNS = DefUse->getNodesOfCollapsableExplicitAccess(Loc);
+    llvm::SmallVector<const DFNode *, 4> Nodes; 
+    if (DFNS)
+      Nodes.append(DFNS->begin(), DFNS->end());
+    if (Nodes.empty())
+      Nodes.push_back(nullptr);
+    for (auto *N : Nodes) {
       MemoryLocationRange ExpLoc = aggregate(R, N, Loc, this).first;
       MemoryLocationRange NewLoc(Loc);
       NewLoc.Kind |= MemoryLocationRange::LocKind::Hint;