[llvm] r275122 - [CFLAA] Simplify CFLGraphBuilder. NFC.

George Burgess IV via llvm-commits llvm-commits at lists.llvm.org
Mon Jul 11 15:59:10 PDT 2016


Author: gbiv
Date: Mon Jul 11 17:59:09 2016
New Revision: 275122

URL: http://llvm.org/viewvc/llvm-project?rev=275122&view=rev
Log:
[CFLAA] Simplify CFLGraphBuilder. NFC.

This patch simplifies the graph builder by encoding nodes as {Value,
Dereference Level} pairs. This lets us kill edge types, and allows us to
get rid of hacks in StratifiedSets (like addAttrsBelow/...). This
simplification also allows us to remove InstantiatedRelations and
InstantiatedAttrs.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D22080

Modified:
    llvm/trunk/lib/Analysis/AliasAnalysisSummary.h
    llvm/trunk/lib/Analysis/CFLGraph.h
    llvm/trunk/lib/Analysis/CFLSteensAliasAnalysis.cpp
    llvm/trunk/lib/Analysis/StratifiedSets.h

Modified: llvm/trunk/lib/Analysis/AliasAnalysisSummary.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/AliasAnalysisSummary.h?rev=275122&r1=275121&r2=275122&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/AliasAnalysisSummary.h (original)
+++ llvm/trunk/lib/Analysis/AliasAnalysisSummary.h Mon Jul 11 17:59:09 2016
@@ -35,6 +35,7 @@
 #ifndef LLVM_ANALYSIS_ALIASANALYSISSUMMARY_H
 #define LLVM_ANALYSIS_ALIASANALYSISSUMMARY_H
 
+#include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/IR/CallSite.h"
@@ -166,6 +167,25 @@ struct InstantiatedAttr {
 Optional<InstantiatedAttr> instantiateExternalAttribute(ExternalAttribute,
                                                         CallSite);
 }
+
+template <> struct DenseMapInfo<cflaa::InstantiatedValue> {
+  static inline cflaa::InstantiatedValue getEmptyKey() {
+    return cflaa::InstantiatedValue{DenseMapInfo<Value *>::getEmptyKey(),
+                                    DenseMapInfo<unsigned>::getEmptyKey()};
+  }
+  static inline cflaa::InstantiatedValue getTombstoneKey() {
+    return cflaa::InstantiatedValue{DenseMapInfo<Value *>::getTombstoneKey(),
+                                    DenseMapInfo<unsigned>::getTombstoneKey()};
+  }
+  static unsigned getHashValue(const cflaa::InstantiatedValue &IV) {
+    return DenseMapInfo<std::pair<Value *, unsigned>>::getHashValue(
+        std::make_pair(IV.Val, IV.DerefLevel));
+  }
+  static bool isEqual(const cflaa::InstantiatedValue &LHS,
+                      const cflaa::InstantiatedValue &RHS) {
+    return LHS.Val == RHS.Val && LHS.DerefLevel == RHS.DerefLevel;
+  }
+};
 }
 
 #endif

Modified: llvm/trunk/lib/Analysis/CFLGraph.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/CFLGraph.h?rev=275122&r1=275121&r2=275122&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/CFLGraph.h (original)
+++ llvm/trunk/lib/Analysis/CFLGraph.h Mon Jul 11 17:59:09 2016
@@ -16,45 +16,29 @@
 #define LLVM_ANALYSIS_CFLGRAPH_H
 
 #include "AliasAnalysisSummary.h"
-#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/IR/InstVisitor.h"
 #include "llvm/IR/Instructions.h"
 
 namespace llvm {
 namespace cflaa {
-/// Edges can be one of four "weights" -- each weight must have an inverse
-/// weight (Assign has Assign; Reference has Dereference).
-enum class EdgeType {
-  /// The weight assigned when assigning from or to a value. For example, in:
-  /// %b = getelementptr %a, 0
-  /// ...The relationships are %b assign %a, and %a assign %b. This used to be
-  /// two edges, but having a distinction bought us nothing.
-  Assign,
-
-  /// The edge used when we have an edge going from some handle to a Value.
-  /// Examples of this include:
-  /// %b = load %a              (%b Dereference %a)
-  /// %b = extractelement %a, 0 (%a Dereference %b)
-  Dereference,
-
-  /// The edge used when our edge goes from a value to a handle that may have
-  /// contained it at some point. Examples:
-  /// %b = load %a              (%a Reference %b)
-  /// %b = extractelement %a, 0 (%b Reference %a)
-  Reference
-};
 
 /// \brief The Program Expression Graph (PEG) of CFL analysis
 /// CFLGraph is auxiliary data structure used by CFL-based alias analysis to
 /// describe flow-insensitive pointer-related behaviors. Given an LLVM function,
 /// the main purpose of this graph is to abstract away unrelated facts and
 /// translate the rest into a form that can be easily digested by CFL analyses.
+/// Each Node in the graph is an InstantiatedValue, and each edge represent a
+/// pointer assignment between InstantiatedValue. Pointer
+/// references/dereferences are not explicitly stored in the graph: we
+/// implicitly assume that for each node (X, I) it has a dereference edge to (X,
+/// I+1) and a reference edge to (X, I-1).
 class CFLGraph {
-  typedef Value *Node;
+public:
+  typedef InstantiatedValue Node;
 
   struct Edge {
-    EdgeType Type;
     Node Other;
   };
 
@@ -65,48 +49,56 @@ class CFLGraph {
     AliasAttrs Attr;
   };
 
-  typedef DenseMap<Node, NodeInfo> NodeMap;
-  NodeMap NodeImpls;
+  class ValueInfo {
+    std::vector<NodeInfo> Levels;
 
-  // Gets the inverse of a given EdgeType.
-  static EdgeType flipWeight(EdgeType Initial) {
-    switch (Initial) {
-    case EdgeType::Assign:
-      return EdgeType::Assign;
-    case EdgeType::Dereference:
-      return EdgeType::Reference;
-    case EdgeType::Reference:
-      return EdgeType::Dereference;
+  public:
+    bool addNodeToLevel(unsigned Level) {
+      auto NumLevels = Levels.size();
+      if (NumLevels > Level)
+        return false;
+      Levels.resize(Level + 1);
+      return true;
+    }
+
+    NodeInfo &getNodeInfoAtLevel(unsigned Level) {
+      assert(Level < Levels.size());
+      return Levels[Level];
+    }
+    const NodeInfo &getNodeInfoAtLevel(unsigned Level) const {
+      assert(Level < Levels.size());
+      return Levels[Level];
     }
-    llvm_unreachable("Incomplete coverage of EdgeType enum");
-  }
+
+    unsigned getNumLevels() const { return Levels.size(); }
+  };
+
+private:
+  typedef DenseMap<Value *, ValueInfo> ValueMap;
+  ValueMap ValueImpls;
 
   const NodeInfo *getNode(Node N) const {
-    auto Itr = NodeImpls.find(N);
-    if (Itr == NodeImpls.end())
+    auto Itr = ValueImpls.find(N.Val);
+    if (Itr == ValueImpls.end() || Itr->second.getNumLevels() <= N.DerefLevel)
       return nullptr;
-    return &Itr->second;
+    return &Itr->second.getNodeInfoAtLevel(N.DerefLevel);
   }
   NodeInfo *getNode(Node N) {
-    auto Itr = NodeImpls.find(N);
-    if (Itr == NodeImpls.end())
+    auto Itr = ValueImpls.find(N.Val);
+    if (Itr == ValueImpls.end() || Itr->second.getNumLevels() <= N.DerefLevel)
       return nullptr;
-    return &Itr->second;
+    return &Itr->second.getNodeInfoAtLevel(N.DerefLevel);
   }
 
-  static Node nodeDeref(const NodeMap::value_type &P) { return P.first; }
-  typedef std::pointer_to_unary_function<const NodeMap::value_type &, Node>
-      NodeDerefFun;
-
 public:
-  typedef EdgeList::const_iterator const_edge_iterator;
-  typedef mapped_iterator<NodeMap::const_iterator, NodeDerefFun>
-      const_node_iterator;
-
-  bool addNode(Node N) {
-    return NodeImpls
-        .insert(std::make_pair(N, NodeInfo{EdgeList(), getAttrNone()}))
-        .second;
+  typedef ValueMap::const_iterator const_value_iterator;
+
+  bool addNode(Node N, AliasAttrs Attr = AliasAttrs()) {
+    assert(N.Val != nullptr);
+    auto &ValInfo = ValueImpls[N.Val];
+    auto Changed = ValInfo.addNodeToLevel(N.DerefLevel);
+    ValInfo.getNodeInfoAtLevel(N.DerefLevel).Attr |= Attr;
+    return Changed;
   }
 
   void addAttr(Node N, AliasAttrs Attr) {
@@ -115,14 +107,13 @@ public:
     Info->Attr |= Attr;
   }
 
-  void addEdge(Node From, Node To, EdgeType Type) {
+  void addEdge(Node From, Node To, int64_t Offset = 0) {
     auto *FromInfo = getNode(From);
     assert(FromInfo != nullptr);
     auto *ToInfo = getNode(To);
     assert(ToInfo != nullptr);
 
-    FromInfo->Edges.push_back(Edge{Type, To});
-    ToInfo->Edges.push_back(Edge{flipWeight(Type), From});
+    FromInfo->Edges.push_back(Edge{To});
   }
 
   AliasAttrs attrFor(Node N) const {
@@ -131,21 +122,10 @@ public:
     return Info->Attr;
   }
 
-  iterator_range<const_edge_iterator> edgesFor(Node N) const {
-    auto *Info = getNode(N);
-    assert(Info != nullptr);
-    auto &Edges = Info->Edges;
-    return make_range(Edges.begin(), Edges.end());
-  }
-
-  iterator_range<const_node_iterator> nodes() const {
-    return make_range<const_node_iterator>(
-        map_iterator(NodeImpls.begin(), NodeDerefFun(nodeDeref)),
-        map_iterator(NodeImpls.end(), NodeDerefFun(nodeDeref)));
+  iterator_range<const_value_iterator> value_mappings() const {
+    return make_range<const_value_iterator>(ValueImpls.begin(),
+                                            ValueImpls.end());
   }
-
-  bool empty() const { return NodeImpls.empty(); }
-  std::size_t size() const { return NodeImpls.size(); }
 };
 
 ///\brief A builder class used to create CFLGraph instance from a given function
@@ -165,10 +145,6 @@ template <typename CFLAA> class CFLGraph
   CFLGraph Graph;
   SmallVector<Value *, 4> ReturnedValues;
 
-  // Auxiliary structures used by the builder
-  SmallVector<InstantiatedRelation, 8> InstantiatedRelations;
-  SmallVector<InstantiatedAttr, 8> InstantiatedAttrs;
-
   // Helper class
   /// Gets the edges our graph should have, based on an Instruction*
   class GetEdgesVisitor : public InstVisitor<GetEdgesVisitor, void> {
@@ -177,8 +153,6 @@ template <typename CFLAA> class CFLGraph
 
     CFLGraph &Graph;
     SmallVectorImpl<Value *> &ReturnValues;
-    SmallVectorImpl<InstantiatedRelation> &InstantiatedRelations;
-    SmallVectorImpl<InstantiatedAttr> &InstantiatedAttrs;
 
     static bool hasUsefulEdges(ConstantExpr *CE) {
       // ConstantExpr doesn't have terminators, invokes, or fences, so only
@@ -203,42 +177,47 @@ template <typename CFLAA> class CFLGraph
       return false;
     }
 
-    void addNode(Value *Val) {
-      assert(Val != nullptr);
-      if (!Graph.addNode(Val))
-        return;
-
-      if (isa<GlobalValue>(Val)) {
-        Graph.addAttr(Val, getGlobalOrArgAttrFromValue(*Val));
-        // Currently we do not attempt to be smart on globals
-        InstantiatedAttrs.push_back(
-            InstantiatedAttr{InstantiatedValue{Val, 1}, getAttrUnknown()});
-      } else if (auto CExpr = dyn_cast<ConstantExpr>(Val))
-        if (hasUsefulEdges(CExpr))
-          visitConstantExpr(CExpr);
-    }
-
-    void addNodeWithAttr(Value *Val, AliasAttrs Attr) {
-      addNode(Val);
-      Graph.addAttr(Val, Attr);
+    void addNode(Value *Val, AliasAttrs Attr = AliasAttrs()) {
+      assert(Val != nullptr && Val->getType()->isPointerTy());
+      if (auto GVal = dyn_cast<GlobalValue>(Val)) {
+        if (Graph.addNode(InstantiatedValue{GVal, 0},
+                          getGlobalOrArgAttrFromValue(*GVal)))
+          Graph.addNode(InstantiatedValue{GVal, 1}, getAttrUnknown());
+      } else if (auto CExpr = dyn_cast<ConstantExpr>(Val)) {
+        if (hasUsefulEdges(CExpr)) {
+          if (Graph.addNode(InstantiatedValue{CExpr, 0}))
+            visitConstantExpr(CExpr);
+        }
+      } else
+        Graph.addNode(InstantiatedValue{Val, 0}, Attr);
     }
 
-    void addEdge(Value *From, Value *To, EdgeType Type) {
+    void addAssignEdge(Value *From, Value *To, int64_t Offset = 0) {
       assert(From != nullptr && To != nullptr);
       if (!From->getType()->isPointerTy() || !To->getType()->isPointerTy())
         return;
       addNode(From);
-      if (To != From)
+      if (To != From) {
         addNode(To);
-      Graph.addEdge(From, To, Type);
+        Graph.addEdge(InstantiatedValue{From, 0}, InstantiatedValue{To, 0},
+                      Offset);
+      }
+    }
+
+    void addDerefEdge(Value *From, Value *To) {
+      assert(From != nullptr && To != nullptr);
+      if (!From->getType()->isPointerTy() || !To->getType()->isPointerTy())
+        return;
+      addNode(From);
+      addNode(To);
+      Graph.addNode(InstantiatedValue{From, 1});
+      Graph.addEdge(InstantiatedValue{From, 1}, InstantiatedValue{To, 0});
     }
 
   public:
     GetEdgesVisitor(CFLGraphBuilder &Builder)
         : AA(Builder.Analysis), TLI(Builder.TLI), Graph(Builder.Graph),
-          ReturnValues(Builder.ReturnedValues),
-          InstantiatedRelations(Builder.InstantiatedRelations),
-          InstantiatedAttrs(Builder.InstantiatedAttrs) {}
+          ReturnValues(Builder.ReturnedValues) {}
 
     void visitInstruction(Instruction &) {
       llvm_unreachable("Unsupported instruction encountered");
@@ -255,46 +234,46 @@ template <typename CFLAA> class CFLGraph
 
     void visitPtrToIntInst(PtrToIntInst &Inst) {
       auto *Ptr = Inst.getOperand(0);
-      addNodeWithAttr(Ptr, getAttrEscaped());
+      addNode(Ptr, getAttrEscaped());
     }
 
     void visitIntToPtrInst(IntToPtrInst &Inst) {
       auto *Ptr = &Inst;
-      addNodeWithAttr(Ptr, getAttrUnknown());
+      addNode(Ptr, getAttrUnknown());
     }
 
     void visitCastInst(CastInst &Inst) {
       auto *Src = Inst.getOperand(0);
-      addEdge(Src, &Inst, EdgeType::Assign);
+      addAssignEdge(Src, &Inst);
     }
 
     void visitBinaryOperator(BinaryOperator &Inst) {
       auto *Op1 = Inst.getOperand(0);
       auto *Op2 = Inst.getOperand(1);
-      addEdge(Op1, &Inst, EdgeType::Assign);
-      addEdge(Op2, &Inst, EdgeType::Assign);
+      addAssignEdge(Op1, &Inst);
+      addAssignEdge(Op2, &Inst);
     }
 
     void visitAtomicCmpXchgInst(AtomicCmpXchgInst &Inst) {
       auto *Ptr = Inst.getPointerOperand();
       auto *Val = Inst.getNewValOperand();
-      addEdge(Ptr, Val, EdgeType::Dereference);
+      addDerefEdge(Ptr, Val);
     }
 
     void visitAtomicRMWInst(AtomicRMWInst &Inst) {
       auto *Ptr = Inst.getPointerOperand();
       auto *Val = Inst.getValOperand();
-      addEdge(Ptr, Val, EdgeType::Dereference);
+      addDerefEdge(Ptr, Val);
     }
 
     void visitPHINode(PHINode &Inst) {
       for (Value *Val : Inst.incoming_values())
-        addEdge(Val, &Inst, EdgeType::Assign);
+        addAssignEdge(Val, &Inst);
     }
 
     void visitGetElementPtrInst(GetElementPtrInst &Inst) {
       auto *Op = Inst.getPointerOperand();
-      addEdge(Op, &Inst, EdgeType::Assign);
+      addAssignEdge(Op, &Inst);
     }
 
     void visitSelectInst(SelectInst &Inst) {
@@ -305,22 +284,22 @@ template <typename CFLAA> class CFLGraph
 
       auto *TrueVal = Inst.getTrueValue();
       auto *FalseVal = Inst.getFalseValue();
-      addEdge(TrueVal, &Inst, EdgeType::Assign);
-      addEdge(FalseVal, &Inst, EdgeType::Assign);
+      addAssignEdge(TrueVal, &Inst);
+      addAssignEdge(FalseVal, &Inst);
     }
 
-    void visitAllocaInst(AllocaInst &Inst) { Graph.addNode(&Inst); }
+    void visitAllocaInst(AllocaInst &Inst) { addNode(&Inst); }
 
     void visitLoadInst(LoadInst &Inst) {
       auto *Ptr = Inst.getPointerOperand();
       auto *Val = &Inst;
-      addEdge(Val, Ptr, EdgeType::Reference);
+      addDerefEdge(Ptr, Val);
     }
 
     void visitStoreInst(StoreInst &Inst) {
       auto *Ptr = Inst.getPointerOperand();
       auto *Val = Inst.getValueOperand();
-      addEdge(Ptr, Val, EdgeType::Dereference);
+      addDerefEdge(Ptr, Val);
     }
 
     void visitVAArgInst(VAArgInst &Inst) {
@@ -332,7 +311,7 @@ template <typename CFLAA> class CFLGraph
       // For now, we'll handle this like a landingpad instruction (by placing
       // the
       // result in its own group, and having that group alias externals).
-      addNodeWithAttr(&Inst, getAttrUnknown());
+      addNode(&Inst, getAttrUnknown());
     }
 
     static bool isFunctionExternal(Function *Fn) {
@@ -363,15 +342,18 @@ template <typename CFLAA> class CFLGraph
         auto &RetParamRelations = Summary->RetParamRelations;
         for (auto &Relation : RetParamRelations) {
           auto IRelation = instantiateExternalRelation(Relation, CS);
-          if (IRelation.hasValue())
-            InstantiatedRelations.push_back(*IRelation);
+          if (IRelation.hasValue()) {
+            Graph.addNode(IRelation->From);
+            Graph.addNode(IRelation->To);
+            Graph.addEdge(IRelation->From, IRelation->To);
+          }
         }
 
         auto &RetParamAttributes = Summary->RetParamAttributes;
         for (auto &Attribute : RetParamAttributes) {
           auto IAttr = instantiateExternalAttribute(Attribute, CS);
           if (IAttr.hasValue())
-            InstantiatedAttrs.push_back(*IAttr);
+            Graph.addNode(IAttr->IValue, IAttr->Attr);
         }
       }
 
@@ -383,7 +365,8 @@ template <typename CFLAA> class CFLGraph
 
       // Make sure all arguments and return value are added to the graph first
       for (Value *V : CS.args())
-        addNode(V);
+        if (V->getType()->isPointerTy())
+          addNode(V);
       if (Inst->getType()->isPointerTy())
         addNode(Inst);
 
@@ -413,23 +396,20 @@ template <typename CFLAA> class CFLGraph
         for (Value *V : CS.args()) {
           if (V->getType()->isPointerTy()) {
             // The argument itself escapes.
-            addNodeWithAttr(V, getAttrEscaped());
+            Graph.addAttr(InstantiatedValue{V, 0}, getAttrEscaped());
             // The fate of argument memory is unknown. Note that since
-            // AliasAttrs
-            // is transitive with respect to dereference, we only need to
-            // specify
-            // it for the first-level memory.
-            InstantiatedAttrs.push_back(
-                InstantiatedAttr{InstantiatedValue{V, 1}, getAttrUnknown()});
+            // AliasAttrs is transitive with respect to dereference, we only
+            // need to specify it for the first-level memory.
+            Graph.addNode(InstantiatedValue{V, 1}, getAttrUnknown());
           }
         }
 
       if (Inst->getType()->isPointerTy()) {
         auto *Fn = CS.getCalledFunction();
         if (Fn == nullptr || !Fn->doesNotAlias(0))
-          // No need to call addNodeWithAttr() since we've added Inst at the
+          // No need to call addNode() since we've added Inst at the
           // beginning of this function and we know it is not a global.
-          Graph.addAttr(Inst, getAttrUnknown());
+          Graph.addAttr(InstantiatedValue{Inst, 0}, getAttrUnknown());
       }
     }
 
@@ -440,40 +420,40 @@ template <typename CFLAA> class CFLGraph
     void visitExtractElementInst(ExtractElementInst &Inst) {
       auto *Ptr = Inst.getVectorOperand();
       auto *Val = &Inst;
-      addEdge(Val, Ptr, EdgeType::Reference);
+      addDerefEdge(Ptr, Val);
     }
 
     void visitInsertElementInst(InsertElementInst &Inst) {
       auto *Vec = Inst.getOperand(0);
       auto *Val = Inst.getOperand(1);
-      addEdge(Vec, &Inst, EdgeType::Assign);
-      addEdge(&Inst, Val, EdgeType::Dereference);
+      addAssignEdge(Vec, &Inst);
+      addDerefEdge(&Inst, Val);
     }
 
     void visitLandingPadInst(LandingPadInst &Inst) {
       // Exceptions come from "nowhere", from our analysis' perspective.
       // So we place the instruction its own group, noting that said group may
       // alias externals
-      addNodeWithAttr(&Inst, getAttrUnknown());
+      addNode(&Inst, getAttrUnknown());
     }
 
     void visitInsertValueInst(InsertValueInst &Inst) {
       auto *Agg = Inst.getOperand(0);
       auto *Val = Inst.getOperand(1);
-      addEdge(Agg, &Inst, EdgeType::Assign);
-      addEdge(&Inst, Val, EdgeType::Dereference);
+      addAssignEdge(Agg, &Inst);
+      addDerefEdge(&Inst, Val);
     }
 
     void visitExtractValueInst(ExtractValueInst &Inst) {
       auto *Ptr = Inst.getAggregateOperand();
-      addEdge(&Inst, Ptr, EdgeType::Reference);
+      addDerefEdge(Ptr, &Inst);
     }
 
     void visitShuffleVectorInst(ShuffleVectorInst &Inst) {
       auto *From1 = Inst.getOperand(0);
       auto *From2 = Inst.getOperand(1);
-      addEdge(From1, &Inst, EdgeType::Assign);
-      addEdge(From2, &Inst, EdgeType::Assign);
+      addAssignEdge(From1, &Inst);
+      addAssignEdge(From2, &Inst);
     }
 
     void visitConstantExpr(ConstantExpr *CE) {
@@ -504,11 +484,10 @@ template <typename CFLAA> class CFLGraph
 
   void addArgumentToGraph(Argument &Arg) {
     if (Arg.getType()->isPointerTy()) {
-      Graph.addNode(&Arg);
-      Graph.addAttr(&Arg, getGlobalOrArgAttrFromValue(Arg));
+      Graph.addNode(InstantiatedValue{&Arg, 0},
+                    getGlobalOrArgAttrFromValue(Arg));
       // Pointees of a formal parameter is known to the caller
-      InstantiatedAttrs.push_back(
-          InstantiatedAttr{InstantiatedValue{&Arg, 1}, getAttrCaller()});
+      Graph.addNode(InstantiatedValue{&Arg, 1}, getAttrCaller());
     }
   }
 
@@ -518,19 +497,21 @@ template <typename CFLAA> class CFLGraph
   //   %0 = load i16* getelementptr ([1 x i16]* @a, 0, 0), align 2
   // addInstructionToGraph would add both the `load` and `getelementptr`
   // instructions to the graph appropriately.
-  void addInstructionToGraph(Instruction &Inst) {
+  void addInstructionToGraph(GetEdgesVisitor &Visitor, Instruction &Inst) {
     if (!hasUsefulEdges(&Inst))
       return;
 
-    GetEdgesVisitor(*this).visit(Inst);
+    Visitor.visit(Inst);
   }
 
   // Builds the graph needed for constructing the StratifiedSets for the given
   // function
   void buildGraphFrom(Function &Fn) {
+    GetEdgesVisitor Visitor(*this);
+
     for (auto &Bb : Fn.getBasicBlockList())
       for (auto &Inst : Bb.getInstList())
-        addInstructionToGraph(Inst);
+        addInstructionToGraph(Visitor, Inst);
 
     for (auto &Arg : Fn.args())
       addArgumentToGraph(Arg);
@@ -546,12 +527,6 @@ public:
   const SmallVector<Value *, 4> &getReturnValues() const {
     return ReturnedValues;
   }
-  const SmallVector<InstantiatedRelation, 8> &getInstantiatedRelations() const {
-    return InstantiatedRelations;
-  }
-  const SmallVector<InstantiatedAttr, 8> &getInstantiatedAttrs() const {
-    return InstantiatedAttrs;
-  }
 };
 }
 }

Modified: llvm/trunk/lib/Analysis/CFLSteensAliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/CFLSteensAliasAnalysis.cpp?rev=275122&r1=275121&r2=275122&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/CFLSteensAliasAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/CFLSteensAliasAnalysis.cpp Mon Jul 11 17:59:09 2016
@@ -67,14 +67,16 @@ CFLSteensAAResult::~CFLSteensAAResult()
 
 /// Information we have about a function and would like to keep around.
 class CFLSteensAAResult::FunctionInfo {
-  StratifiedSets<Value *> Sets;
+  StratifiedSets<InstantiatedValue> Sets;
   AliasSummary Summary;
 
 public:
   FunctionInfo(Function &Fn, const SmallVectorImpl<Value *> &RetVals,
-               StratifiedSets<Value *> S);
+               StratifiedSets<InstantiatedValue> S);
 
-  const StratifiedSets<Value *> &getStratifiedSets() const { return Sets; }
+  const StratifiedSets<InstantiatedValue> &getStratifiedSets() const {
+    return Sets;
+  }
   const AliasSummary &getAliasSummary() const { return Summary; }
 };
 
@@ -84,21 +86,10 @@ static Optional<Function *> parentFuncti
 const StratifiedIndex StratifiedLink::SetSentinel =
     std::numeric_limits<StratifiedIndex>::max();
 
-namespace {
-
-/// StratifiedSets call for knowledge of "direction", so this is how we
-/// represent that locally.
-enum class Level { Same, Above, Below };
-}
-
 //===----------------------------------------------------------------------===//
 // Function declarations that require types defined in the namespace above
 //===----------------------------------------------------------------------===//
 
-/// Gets the "Level" that one should travel in StratifiedSets
-/// given an EdgeType.
-static Level directionOfEdgeType(EdgeType);
-
 /// Determines whether it would be pointless to add the given Value to our sets.
 static bool canSkipAddingToSets(Value *Val);
 
@@ -113,18 +104,6 @@ static Optional<Function *> parentFuncti
   return None;
 }
 
-static Level directionOfEdgeType(EdgeType Weight) {
-  switch (Weight) {
-  case EdgeType::Reference:
-    return Level::Above;
-  case EdgeType::Dereference:
-    return Level::Below;
-  case EdgeType::Assign:
-    return Level::Same;
-  }
-  llvm_unreachable("Incomplete switch coverage");
-}
-
 static bool canSkipAddingToSets(Value *Val) {
   // Constants can share instances, which may falsely unify multiple
   // sets, e.g. in
@@ -148,7 +127,7 @@ static bool canSkipAddingToSets(Value *V
 
 CFLSteensAAResult::FunctionInfo::FunctionInfo(
     Function &Fn, const SmallVectorImpl<Value *> &RetVals,
-    StratifiedSets<Value *> S)
+    StratifiedSets<InstantiatedValue> S)
     : Sets(std::move(S)) {
   // Historically, an arbitrary upper-bound of 50 args was selected. We may want
   // to remove this if it doesn't really matter in practice.
@@ -197,7 +176,7 @@ CFLSteensAAResult::FunctionInfo::Functio
   for (auto *RetVal : RetVals) {
     assert(RetVal != nullptr);
     assert(RetVal->getType()->isPointerTy());
-    auto RetInfo = Sets.find(RetVal);
+    auto RetInfo = Sets.find(InstantiatedValue{RetVal, 0});
     if (RetInfo.hasValue())
       AddToRetParamRelations(0, RetInfo->Index);
   }
@@ -206,7 +185,7 @@ CFLSteensAAResult::FunctionInfo::Functio
   unsigned I = 0;
   for (auto &Param : Fn.args()) {
     if (Param.getType()->isPointerTy()) {
-      auto ParamInfo = Sets.find(&Param);
+      auto ParamInfo = Sets.find(InstantiatedValue{&Param, 0});
       if (ParamInfo.hasValue())
         AddToRetParamRelations(I + 1, ParamInfo->Index);
     }
@@ -217,62 +196,41 @@ CFLSteensAAResult::FunctionInfo::Functio
 // Builds the graph + StratifiedSets for a function.
 CFLSteensAAResult::FunctionInfo CFLSteensAAResult::buildSetsFrom(Function *Fn) {
   CFLGraphBuilder<CFLSteensAAResult> GraphBuilder(*this, TLI, *Fn);
-  StratifiedSetsBuilder<Value *> SetBuilder;
+  StratifiedSetsBuilder<InstantiatedValue> SetBuilder;
 
+  // Add all CFLGraph nodes and all Dereference edges to StratifiedSets
   auto &Graph = GraphBuilder.getCFLGraph();
-  SmallVector<Value *, 16> Worklist;
-  for (auto Node : Graph.nodes())
-    Worklist.push_back(Node);
-
-  while (!Worklist.empty()) {
-    auto *CurValue = Worklist.pop_back_val();
-    SetBuilder.add(CurValue);
-    if (canSkipAddingToSets(CurValue))
+  for (const auto &Mapping : Graph.value_mappings()) {
+    auto Val = Mapping.first;
+    if (canSkipAddingToSets(Val))
       continue;
+    auto &ValueInfo = Mapping.second;
 
-    auto Attr = Graph.attrFor(CurValue);
-    SetBuilder.noteAttributes(CurValue, Attr);
-
-    for (const auto &Edge : Graph.edgesFor(CurValue)) {
-      auto Label = Edge.Type;
-      auto *OtherValue = Edge.Other;
-
-      if (canSkipAddingToSets(OtherValue))
-        continue;
-
-      bool Added;
-      switch (directionOfEdgeType(Label)) {
-      case Level::Above:
-        Added = SetBuilder.addAbove(CurValue, OtherValue);
-        break;
-      case Level::Below:
-        Added = SetBuilder.addBelow(CurValue, OtherValue);
-        break;
-      case Level::Same:
-        Added = SetBuilder.addWith(CurValue, OtherValue);
-        break;
-      }
-
-      if (Added)
-        Worklist.push_back(OtherValue);
+    assert(ValueInfo.getNumLevels() > 0);
+    SetBuilder.add(InstantiatedValue{Val, 0});
+    SetBuilder.noteAttributes(InstantiatedValue{Val, 0},
+                              ValueInfo.getNodeInfoAtLevel(0).Attr);
+    for (unsigned I = 0, E = ValueInfo.getNumLevels() - 1; I < E; ++I) {
+      SetBuilder.add(InstantiatedValue{Val, I + 1});
+      SetBuilder.noteAttributes(InstantiatedValue{Val, I + 1},
+                                ValueInfo.getNodeInfoAtLevel(I + 1).Attr);
+      SetBuilder.addBelow(InstantiatedValue{Val, I},
+                          InstantiatedValue{Val, I + 1});
     }
   }
 
-  // Special handling for interprocedural aliases
-  for (auto &Edge : GraphBuilder.getInstantiatedRelations()) {
-    auto FromVal = Edge.From.Val;
-    auto ToVal = Edge.To.Val;
-    SetBuilder.add(FromVal);
-    SetBuilder.add(ToVal);
-    SetBuilder.addBelowWith(FromVal, Edge.From.DerefLevel, ToVal,
-                            Edge.To.DerefLevel);
-  }
+  // Add all assign edges to StratifiedSets
+  for (const auto &Mapping : Graph.value_mappings()) {
+    auto Val = Mapping.first;
+    if (canSkipAddingToSets(Val))
+      continue;
+    auto &ValueInfo = Mapping.second;
 
-  // Special handling for interprocedural attributes
-  for (auto &IPAttr : GraphBuilder.getInstantiatedAttrs()) {
-    auto Val = IPAttr.IValue.Val;
-    SetBuilder.add(Val);
-    SetBuilder.addAttributesBelow(Val, IPAttr.IValue.DerefLevel, IPAttr.Attr);
+    for (unsigned I = 0, E = ValueInfo.getNumLevels(); I < E; ++I) {
+      auto Src = InstantiatedValue{Val, I};
+      for (auto &Edge : ValueInfo.getNodeInfoAtLevel(I).Edges)
+        SetBuilder.addWith(Src, Edge.Other);
+    }
   }
 
   return FunctionInfo(*Fn, GraphBuilder.getReturnValues(), SetBuilder.build());
@@ -349,11 +307,11 @@ AliasResult CFLSteensAAResult::query(con
   assert(MaybeInfo.hasValue());
 
   auto &Sets = MaybeInfo->getStratifiedSets();
-  auto MaybeA = Sets.find(ValA);
+  auto MaybeA = Sets.find(InstantiatedValue{ValA, 0});
   if (!MaybeA.hasValue())
     return MayAlias;
 
-  auto MaybeB = Sets.find(ValB);
+  auto MaybeB = Sets.find(InstantiatedValue{ValB, 0});
   if (!MaybeB.hasValue())
     return MayAlias;
 

Modified: llvm/trunk/lib/Analysis/StratifiedSets.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/StratifiedSets.h?rev=275122&r1=275121&r2=275122&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/StratifiedSets.h (original)
+++ llvm/trunk/lib/Analysis/StratifiedSets.h Mon Jul 11 17:59:09 2016
@@ -386,46 +386,12 @@ public:
     return addAtMerging(ToAdd, Below);
   }
 
-  /// \brief Set the AliasAttrs of the set "Level"-levels below "Main". If
-  /// there is no set below "Main", create one for it.
-  void addAttributesBelow(const T &Main, unsigned Level, AliasAttrs Attr) {
-    assert(has(Main));
-    auto Index = *indexOf(Main);
-    auto *Link = &linksAt(Index);
-
-    for (unsigned I = 0; I < Level; ++I) {
-      Index = Link->hasBelow() ? Link->getBelow() : addLinkBelow(Index);
-      Link = &linksAt(Index);
-    }
-    Link->setAttrs(Attr);
-  }
-
   bool addWith(const T &Main, const T &ToAdd) {
     assert(has(Main));
     auto MainIndex = *indexOf(Main);
     return addAtMerging(ToAdd, MainIndex);
   }
 
-  /// \brief Merge the set "MainBelow"-levels below "Main" and the set
-  /// "ToAddBelow"-levels below "ToAdd".
-  void addBelowWith(const T &Main, unsigned MainBelow, const T &ToAdd,
-                    unsigned ToAddBelow) {
-    assert(has(Main));
-    assert(has(ToAdd));
-
-    auto GetIndexBelow = [&](StratifiedIndex Index, unsigned NumLevel) {
-      for (unsigned I = 0; I < NumLevel; ++I) {
-        auto Link = linksAt(Index);
-        Index = Link.hasBelow() ? Link.getBelow() : addLinkBelow(Index);
-      }
-      return Index;
-    };
-    auto MainIndex = GetIndexBelow(*indexOf(Main), MainBelow);
-    auto ToAddIndex = GetIndexBelow(*indexOf(ToAdd), ToAddBelow);
-    if (&linksAt(MainIndex) != &linksAt(ToAddIndex))
-      merge(MainIndex, ToAddIndex);
-  }
-
   void noteAttributes(const T &Main, AliasAttrs NewAttrs) {
     assert(has(Main));
     auto *Info = *get(Main);
@@ -545,6 +511,7 @@ private:
       NewBelow.setAbove(LinksInto->Number);
     }
 
+    LinksInto->setAttrs(LinksFrom->getAttrs());
     LinksFrom->remapTo(LinksInto->Number);
   }
 




More information about the llvm-commits mailing list