//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// address taking.
//
// The offline constraint graph optimization portion includes offline variable
-// substitution algorithms intended to computer pointer and location
+// substitution algorithms intended to compute pointer and location
// equivalences. Pointer equivalences are those pointers that will have the
// same points-to sets, and location equivalences are those variables that
-// always appear together in points-to sets.
+// always appear together in points-to sets. It also includes an offline
+// cycle detection algorithm that allows cycles to be collapsed sooner
+// during solving.
//
// The inclusion constraint solving phase iteratively propagates the inclusion
// constraints until a fixed point is reached. This is an O(N^3) algorithm.
// CallReturnPos. The arguments start at getNode(F) + CallArgPos.
//
// Future Improvements:
-// Offline detection of online cycles. Use of BDD's.
+// Use of BDD's.
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "anders-aa"
#include <algorithm>
#include <set>
#include <list>
+#include <map>
#include <stack>
#include <vector>
#include <queue>
STATISTIC(NumUnified , "Number of variables unified");
STATISTIC(NumErased , "Number of redundant constraints erased");
-namespace {
- const unsigned SelfRep = (unsigned)-1;
- const unsigned Unvisited = (unsigned)-1;
- // Position of the function return node relative to the function node.
- const unsigned CallReturnPos = 1;
- // Position of the function call node relative to the function node.
- const unsigned CallFirstArgPos = 2;
+static const unsigned SelfRep = (unsigned)-1;
+static const unsigned Unvisited = (unsigned)-1;
+// Position of the function return node relative to the function node.
+static const unsigned CallReturnPos = 1;
+// Position of the function call node relative to the function node.
+static const unsigned CallFirstArgPos = 2;
+namespace {
struct BitmapKeyInfo {
static inline SparseBitVector<> *getEmptyKey() {
return reinterpret_cast<SparseBitVector<> *>(-1);
Constraint(ConstraintType Ty, unsigned D, unsigned S, unsigned O = 0)
: Type(Ty), Dest(D), Src(S), Offset(O) {
- assert(Offset == 0 || Ty != AddressOf &&
+ assert((Offset == 0 || Ty != AddressOf) &&
"Offset is illegal on addressof constraints");
}
// it's thing
struct PairKeyInfo {
static inline std::pair<unsigned, unsigned> getEmptyKey() {
- return std::make_pair(~0UL, ~0UL);
+ return std::make_pair(~0U, ~0U);
}
static inline std::pair<unsigned, unsigned> getTombstoneKey() {
- return std::make_pair(~0UL - 1, ~0UL - 1);
+ return std::make_pair(~0U - 1, ~0U - 1);
}
static unsigned getHashValue(const std::pair<unsigned, unsigned> &P) {
return P.first ^ P.second;
struct ConstraintKeyInfo {
static inline Constraint getEmptyKey() {
- return Constraint(Constraint::Copy, ~0UL, ~0UL, ~0UL);
+ return Constraint(Constraint::Copy, ~0U, ~0U, ~0U);
}
static inline Constraint getTombstoneKey() {
- return Constraint(Constraint::Copy, ~0UL - 1, ~0UL - 1, ~0UL - 1);
+ return Constraint(Constraint::Copy, ~0U - 1, ~0U - 1, ~0U - 1);
}
static unsigned getHashValue(const Constraint &C) {
return C.Src ^ C.Dest ^ C.Type ^ C.Offset;
Timestamp = Counter++;
}
- bool isRep() {
+ bool isRep() const {
return( (int) NodeRep < 0 );
}
};
// pointer equivalent but not location equivalent variables. -1 if we have
// no representative node for this pointer equivalence class yet.
std::vector<int> PENLEClass2Node;
+ // Union/Find for HCD
+ std::vector<unsigned> HCDSCCRep;
+ // HCD's offline-detected cycles; "Statically DeTected"
+ // -1 if not part of such a cycle, otherwise a representative node.
+ std::vector<int> SDT;
+ // Whether to use SDT (UniteNodes can use it during solving, but not before)
+ bool SDTActive;
public:
static char ID;
- Andersens() : ModulePass((intptr_t)&ID) {}
+ Andersens() : ModulePass(&ID) {}
bool runOnModule(Module &M) {
InitializeAliasAnalysis(this);
// Free the constraints list, as we don't need it to respond to alias
// requests.
- ObjectNodes.clear();
- ReturnNodes.clear();
- VarargNodes.clear();
std::vector<Constraint>().swap(Constraints);
+ //These are needed for Print() (-analyze in opt)
+ //ObjectNodes.clear();
+ //ReturnNodes.clear();
+ //VarargNodes.clear();
return false;
}
/// getObject - Return the node corresponding to the memory object for the
/// specified global or allocation instruction.
- unsigned getObject(Value *V) {
+ unsigned getObject(Value *V) const {
DenseMap<Value*, unsigned>::iterator I = ObjectNodes.find(V);
assert(I != ObjectNodes.end() &&
"Value does not have an object in the points-to graph!");
/// getReturnNode - Return the node representing the return value for the
/// specified function.
- unsigned getReturnNode(Function *F) {
+ unsigned getReturnNode(Function *F) const {
DenseMap<Function*, unsigned>::iterator I = ReturnNodes.find(F);
assert(I != ReturnNodes.end() && "Function does not return a value!");
return I->second;
/// getVarargNode - Return the node representing the variable arguments
/// formal for the specified function.
- unsigned getVarargNode(Function *F) {
+ unsigned getVarargNode(Function *F) const {
DenseMap<Function*, unsigned>::iterator I = VarargNodes.find(F);
assert(I != VarargNodes.end() && "Function does not take var args!");
return I->second;
unsigned UniteNodes(unsigned First, unsigned Second,
bool UnionByRank = true);
unsigned FindNode(unsigned Node);
+ unsigned FindNode(unsigned Node) const;
void IdentifyObjects(Module &M);
void CollectConstraints(Module &M);
void RewriteConstraints();
void HU();
void HVN();
+ void HCD();
+ void Search(unsigned Node);
void UnitePointerEquivalences();
void SolveConstraints();
bool QueryNode(unsigned Node);
bool AddConstraintsForExternalCall(CallSite CS, Function *F);
- void PrintNode(Node *N);
- void PrintConstraints();
- void PrintConstraint(const Constraint &);
- void PrintLabels();
- void PrintPointsToGraph();
+ void PrintNode(const Node *N) const;
+ void PrintConstraints() const ;
+ void PrintConstraint(const Constraint &) const;
+ void PrintLabels() const;
+ void PrintPointsToGraph() const;
//===------------------------------------------------------------------===//
// Instruction visitation methods for adding constraints
void visitVAArg(VAArgInst &I);
void visitInstruction(Instruction &I);
+ //===------------------------------------------------------------------===//
+ // Implement Analyize interface
+ //
+ void print(std::ostream &O, const Module* M) const {
+ PrintPointsToGraph();
+ }
};
+}
- char Andersens::ID = 0;
- RegisterPass<Andersens> X("anders-aa",
- "Andersen's Interprocedural Alias Analysis");
-
RegisterAnalysisGroup<AliasAnalysis> Y(X);
+char Andersens::ID = 0;
+static RegisterPass<Andersens>
+X("anders-aa", "Andersen's Interprocedural Alias Analysis", false, true);
+
static RegisterAnalysisGroup<AliasAnalysis> Y(X);
- // Initialize Timestamp Counter (static).
- unsigned Andersens::Node::Counter = 0;
-}
+// Initialize Timestamp Counter (static).
+unsigned Andersens::Node::Counter = 0;
ModulePass *llvm::createAndersensPass() { return new Andersens(); }
if (N1->PointsTo->empty())
return NoModRef;
-
+#if FULL_UNIVERSAL
+ if (!UniversalSet->PointsTo->test(FindNode(getNode(P))))
+ return NoModRef; // Universal set does not contain P
+#else
if (!N1->PointsTo->test(UniversalSet))
return NoModRef; // P doesn't point to the universal set.
+#endif
}
return AliasAnalysis::getModRefInfo(CS, P, Size);
/// return true.
///
bool Andersens::pointsToConstantMemory(const Value *P) {
- Node *N = &GraphNodes[FindNode(getNode((Value*)P))];
+ Node *N = &GraphNodes[FindNode(getNode(const_cast<Value*>(P)))];
unsigned i;
for (SparseBitVector<>::iterator bi = N->PointsTo->begin();
/// object N, which contains values indicated by C.
void Andersens::AddGlobalInitializerConstraints(unsigned NodeIndex,
Constant *C) {
- if (C->getType()->isFirstClassType()) {
+ if (C->getType()->isSingleValueType()) {
if (isa<PointerType>(C->getType()))
Constraints.push_back(Constraint(Constraint::Copy, NodeIndex,
getNodeForConstantPointer(C)));
F->getName() == "atol" || F->getName() == "atoll" ||
F->getName() == "remove" || F->getName() == "unlink" ||
F->getName() == "rename" || F->getName() == "memcmp" ||
- F->getName() == "llvm.memset.i32" ||
- F->getName() == "llvm.memset.i64" ||
+ F->getName() == "llvm.memset" ||
F->getName() == "strcmp" || F->getName() == "strncmp" ||
F->getName() == "execl" || F->getName() == "execlp" ||
F->getName() == "execle" || F->getName() == "execv" ||
// These functions do induce points-to edges.
- if (F->getName() == "llvm.memcpy.i32" || F->getName() == "llvm.memcpy.i64" ||
- F->getName() == "llvm.memmove.i32" ||F->getName() == "llvm.memmove.i64" ||
+ if (F->getName() == "llvm.memcpy" ||
+ F->getName() == "llvm.memmove" ||
F->getName() == "memmove") {
- // *Dest = *Src, which requires an artificial graph node to represent the
- // constraint. It is broken up into *Dest = temp, temp = *Src
- unsigned FirstArg = getNode(CS.getArgument(0));
- unsigned SecondArg = getNode(CS.getArgument(1));
- unsigned TempArg = GraphNodes.size();
- GraphNodes.push_back(Node());
- Constraints.push_back(Constraint(Constraint::Store,
- FirstArg, TempArg));
- Constraints.push_back(Constraint(Constraint::Load,
- TempArg, SecondArg));
- return true;
+ const FunctionType *FTy = F->getFunctionType();
+ if (FTy->getNumParams() > 1 &&
+ isa<PointerType>(FTy->getParamType(0)) &&
+ isa<PointerType>(FTy->getParamType(1))) {
+
+ // *Dest = *Src, which requires an artificial graph node to represent the
+ // constraint. It is broken up into *Dest = temp, temp = *Src
+ unsigned FirstArg = getNode(CS.getArgument(0));
+ unsigned SecondArg = getNode(CS.getArgument(1));
+ unsigned TempArg = GraphNodes.size();
+ GraphNodes.push_back(Node());
+ Constraints.push_back(Constraint(Constraint::Store,
+ FirstArg, TempArg));
+ Constraints.push_back(Constraint(Constraint::Load,
+ TempArg, SecondArg));
+ // In addition, Dest = Src
+ Constraints.push_back(Constraint(Constraint::Copy,
+ FirstArg, SecondArg));
+ return true;
+ }
}
// Result = Arg0
if (F->getName() == "realloc" || F->getName() == "strchr" ||
F->getName() == "strrchr" || F->getName() == "strstr" ||
F->getName() == "strtok") {
- Constraints.push_back(Constraint(Constraint::Copy,
- getNode(CS.getInstruction()),
- getNode(CS.getArgument(0))));
- return true;
+ const FunctionType *FTy = F->getFunctionType();
+ if (FTy->getNumParams() > 0 &&
+ isa<PointerType>(FTy->getParamType(0))) {
+ Constraints.push_back(Constraint(Constraint::Copy,
+ getNode(CS.getInstruction()),
+ getNode(CS.getArgument(0))));
+ return true;
+ }
}
return false;
// At some point we should just add constraints for the escaping functions
// at solve time, but this slows down solving. For now, we simply mark
// address taken functions as escaping and treat them as external.
- if (!F->hasInternalLinkage() || AnalyzeUsesOfFunction(F))
+ if (!F->hasLocalLinkage() || AnalyzeUsesOfFunction(F))
AddConstraintsForNonInternalLinkage(F);
if (!F->isDeclaration()) {
}
CallSite::arg_iterator ArgI = CS.arg_begin(), ArgE = CS.arg_end();
+ bool external = !F || F->isDeclaration();
if (F) {
// Direct Call
Function::arg_iterator AI = F->arg_begin(), AE = F->arg_end();
- for (; AI != AE && ArgI != ArgE; ++AI, ++ArgI)
- if (isa<PointerType>(AI->getType())) {
- if (isa<PointerType>((*ArgI)->getType())) {
- // Copy the actual argument into the formal argument.
- Constraints.push_back(Constraint(Constraint::Copy, getNode(AI),
- getNode(*ArgI)));
- } else {
- Constraints.push_back(Constraint(Constraint::Copy, getNode(AI),
- UniversalSet));
- }
- } else if (isa<PointerType>((*ArgI)->getType())) {
+ for (; AI != AE && ArgI != ArgE; ++AI, ++ArgI)
+ {
+#if !FULL_UNIVERSAL
+ if (external && isa<PointerType>((*ArgI)->getType()))
+ {
+ // Add constraint that ArgI can now point to anything due to
+ // escaping, as can everything it points to. The second portion of
+ // this should be taken care of by universal = *universal
+ Constraints.push_back(Constraint(Constraint::Copy,
+ getNode(*ArgI),
+ UniversalSet));
+ }
+#endif
+ if (isa<PointerType>(AI->getType())) {
+ if (isa<PointerType>((*ArgI)->getType())) {
+ // Copy the actual argument into the formal argument.
+ Constraints.push_back(Constraint(Constraint::Copy, getNode(AI),
+ getNode(*ArgI)));
+ } else {
+ Constraints.push_back(Constraint(Constraint::Copy, getNode(AI),
+ UniversalSet));
+ }
+ } else if (isa<PointerType>((*ArgI)->getType())) {
#if FULL_UNIVERSAL
- Constraints.push_back(Constraint(Constraint::Copy,
- UniversalSet,
- getNode(*ArgI)));
+ Constraints.push_back(Constraint(Constraint::Copy,
+ UniversalSet,
+ getNode(*ArgI)));
#else
- Constraints.push_back(Constraint(Constraint::Copy,
- getNode(*ArgI),
- UniversalSet));
+ Constraints.push_back(Constraint(Constraint::Copy,
+ getNode(*ArgI),
+ UniversalSet));
#endif
+ }
}
} else {
//Indirect Call
C.Src = FindEquivalentNode(RHSNode, RHSLabel);
C.Dest = FindEquivalentNode(FindNode(LHSNode), LHSLabel);
- if (C.Src == C.Dest && C.Type == Constraint::Copy
+ if ((C.Src == C.Dest && C.Type == Constraint::Copy)
|| Seen.count(C))
continue;
return NodeIndex;
}
-void Andersens::PrintLabels() {
+void Andersens::PrintLabels() const {
for (unsigned i = 0; i < GraphNodes.size(); ++i) {
if (i < FirstRefNode) {
PrintNode(&GraphNodes[i]);
}
}
+/// The technique used here is described in "The Ant and the
+/// Grasshopper: Fast and Accurate Pointer Analysis for Millions of
+/// Lines of Code. In Programming Language Design and Implementation
+/// (PLDI), June 2007." It is known as the "HCD" (Hybrid Cycle
+/// Detection) algorithm. It is called a hybrid because it performs an
+/// offline analysis and uses its results during the solving (online)
+/// phase. This is just the offline portion; the results of this
+/// operation are stored in SDT and are later used in SolveContraints()
+/// and UniteNodes().
+void Andersens::HCD() {
+ DOUT << "Starting HCD.\n";
+ HCDSCCRep.resize(GraphNodes.size());
+
+ for (unsigned i = 0; i < GraphNodes.size(); ++i) {
+ GraphNodes[i].Edges = new SparseBitVector<>;
+ HCDSCCRep[i] = i;
+ }
+
+ for (unsigned i = 0, e = Constraints.size(); i != e; ++i) {
+ Constraint &C = Constraints[i];
+ assert (C.Src < GraphNodes.size() && C.Dest < GraphNodes.size());
+ if (C.Type == Constraint::AddressOf) {
+ continue;
+ } else if (C.Type == Constraint::Load) {
+ if( C.Offset == 0 )
+ GraphNodes[C.Dest].Edges->set(C.Src + FirstRefNode);
+ } else if (C.Type == Constraint::Store) {
+ if( C.Offset == 0 )
+ GraphNodes[C.Dest + FirstRefNode].Edges->set(C.Src);
+ } else {
+ GraphNodes[C.Dest].Edges->set(C.Src);
+ }
+ }
+
+ Node2DFS.insert(Node2DFS.begin(), GraphNodes.size(), 0);
+ Node2Deleted.insert(Node2Deleted.begin(), GraphNodes.size(), false);
+ Node2Visited.insert(Node2Visited.begin(), GraphNodes.size(), false);
+ SDT.insert(SDT.begin(), GraphNodes.size() / 2, -1);
+
+ DFSNumber = 0;
+ for (unsigned i = 0; i < GraphNodes.size(); ++i) {
+ unsigned Node = HCDSCCRep[i];
+ if (!Node2Deleted[Node])
+ Search(Node);
+ }
+
+ for (unsigned i = 0; i < GraphNodes.size(); ++i)
+ if (GraphNodes[i].Edges != NULL) {
+ delete GraphNodes[i].Edges;
+ GraphNodes[i].Edges = NULL;
+ }
+
+ while( !SCCStack.empty() )
+ SCCStack.pop();
+
+ Node2DFS.clear();
+ Node2Visited.clear();
+ Node2Deleted.clear();
+ HCDSCCRep.clear();
+ DOUT << "HCD complete.\n";
+}
+
+// Component of HCD:
+// Use Nuutila's variant of Tarjan's algorithm to detect
+// Strongly-Connected Components (SCCs). For non-trivial SCCs
+// containing ref nodes, insert the appropriate information in SDT.
+void Andersens::Search(unsigned Node) {
+ unsigned MyDFS = DFSNumber++;
+
+ Node2Visited[Node] = true;
+ Node2DFS[Node] = MyDFS;
+
+ for (SparseBitVector<>::iterator Iter = GraphNodes[Node].Edges->begin(),
+ End = GraphNodes[Node].Edges->end();
+ Iter != End;
+ ++Iter) {
+ unsigned J = HCDSCCRep[*Iter];
+ assert(GraphNodes[J].isRep() && "Debug check; must be representative");
+ if (!Node2Deleted[J]) {
+ if (!Node2Visited[J])
+ Search(J);
+ if (Node2DFS[Node] > Node2DFS[J])
+ Node2DFS[Node] = Node2DFS[J];
+ }
+ }
+
+ if( MyDFS != Node2DFS[Node] ) {
+ SCCStack.push(Node);
+ return;
+ }
+
+ // This node is the root of a SCC, so process it.
+ //
+ // If the SCC is "non-trivial" (not a singleton) and contains a reference
+ // node, we place this SCC into SDT. We unite the nodes in any case.
+ if (!SCCStack.empty() && Node2DFS[SCCStack.top()] >= MyDFS) {
+ SparseBitVector<> SCC;
+
+ SCC.set(Node);
+
+ bool Ref = (Node >= FirstRefNode);
+
+ Node2Deleted[Node] = true;
+
+ do {
+ unsigned P = SCCStack.top(); SCCStack.pop();
+ Ref |= (P >= FirstRefNode);
+ SCC.set(P);
+ HCDSCCRep[P] = Node;
+ } while (!SCCStack.empty() && Node2DFS[SCCStack.top()] >= MyDFS);
+
+ if (Ref) {
+ unsigned Rep = SCC.find_first();
+ assert(Rep < FirstRefNode && "The SCC didn't have a non-Ref node!");
+
+ SparseBitVector<>::iterator i = SCC.begin();
+
+ // Skip over the non-ref nodes
+ while( *i < FirstRefNode )
+ ++i;
+
+ while( i != SCC.end() )
+ SDT[ (*i++) - FirstRefNode ] = Rep;
+ }
+ }
+}
+
+
/// Optimize the constraints by performing offline variable substitution and
/// other optimizations.
void Andersens::OptimizeConstraints() {
DOUT << "Beginning constraint optimization\n";
+ SDTActive = false;
+
// Function related nodes need to stay in the same relative position and can't
// be location equivalent.
for (std::map<unsigned, unsigned>::iterator Iter = MaxK.begin();
if (FindNode(i) == i) {
Node *N = &GraphNodes[i];
delete N->PointsTo;
+ N->PointsTo = NULL;
delete N->PredEdges;
+ N->PredEdges = NULL;
delete N->ImplicitPredEdges;
+ N->ImplicitPredEdges = NULL;
delete N->PointedToBy;
+ N->PointedToBy = NULL;
}
}
+
+ // perform Hybrid Cycle Detection (HCD)
+ HCD();
+ SDTActive = true;
+
+ // No longer any need for the upper half of GraphNodes (for ref nodes).
GraphNodes.erase(GraphNodes.begin() + FirstRefNode, GraphNodes.end());
+
+ // HCD complete.
+
DOUT << "Finished constraint optimization\n";
FirstRefNode = 0;
FirstAdrNode = 0;
}
}
std::queue<unsigned int> TarjanWL;
+#if !FULL_UNIVERSAL
+ // "Rep and special variables" - in order for HCD to maintain conservative
+ // results when !FULL_UNIVERSAL, we need to treat the special variables in
+ // the same way that the !FULL_UNIVERSAL tweak does throughout the rest of
+ // the analysis - it's ok to add edges from the special nodes, but never
+ // *to* the special nodes.
+ std::vector<unsigned int> RSV;
+#endif
while( !CurrWL->empty() ) {
DOUT << "Starting iteration #" << ++NumIters << "\n";
continue;
*(CurrNode->OldPointsTo) |= CurrPointsTo;
+
+ // Check the offline-computed equivalencies from HCD.
+ bool SCC = false;
+ unsigned Rep;
+
+ if (SDT[CurrNodeIndex] >= 0) {
+ SCC = true;
+ Rep = FindNode(SDT[CurrNodeIndex]);
+
+#if !FULL_UNIVERSAL
+ RSV.clear();
+#endif
+ for (SparseBitVector<>::iterator bi = CurrPointsTo.begin();
+ bi != CurrPointsTo.end(); ++bi) {
+ unsigned Node = FindNode(*bi);
+#if !FULL_UNIVERSAL
+ if (Node < NumberSpecialNodes) {
+ RSV.push_back(Node);
+ continue;
+ }
+#endif
+ Rep = UniteNodes(Rep,Node);
+ }
+#if !FULL_UNIVERSAL
+ RSV.push_back(Rep);
+#endif
+
+ NextWL->insert(&GraphNodes[Rep]);
+
+ if ( ! CurrNode->isRep() )
+ continue;
+ }
+
Seen.clear();
/* Now process the constraints for this node. */
li++;
continue;
}
- // TODO: hybrid cycle detection would go here, we should check
- // if it was a statically detected offline equivalence that
- // involves pointers , and if so, remove the redundant constraints.
- const SparseBitVector<> &Solution = CurrPointsTo;
-
- for (SparseBitVector<>::iterator bi = Solution.begin();
- bi != Solution.end();
- ++bi) {
- CurrMember = *bi;
-
- // Need to increment the member by K since that is where we are
- // supposed to copy to/from. Note that in positive weight cycles,
- // which occur in address taking of fields, K can go past
- // MaxK[CurrMember] elements, even though that is all it could point
- // to.
- if (K > 0 && K > MaxK[CurrMember])
- continue;
- else
- CurrMember = FindNode(CurrMember + K);
+ // See if we can use Hybrid Cycle Detection (that is, check
+ // if it was a statically detected offline equivalence that
+ // involves pointers; if so, remove the redundant constraints).
+ if( SCC && K == 0 ) {
+#if FULL_UNIVERSAL
+ CurrMember = Rep;
- // Add an edge to the graph, so we can just do regular bitmap ior next
- // time. It may also let us notice a cycle.
-#if !FULL_UNIVERSAL
- if (*Dest < NumberSpecialNodes)
- continue;
-#endif
if (GraphNodes[*Src].Edges->test_and_set(*Dest))
if (GraphNodes[*Dest].PointsTo |= *(GraphNodes[*Src].PointsTo))
NextWL->insert(&GraphNodes[*Dest]);
+#else
+ for (unsigned i=0; i < RSV.size(); ++i) {
+ CurrMember = RSV[i];
+
+ if (*Dest < NumberSpecialNodes)
+ continue;
+ if (GraphNodes[*Src].Edges->test_and_set(*Dest))
+ if (GraphNodes[*Dest].PointsTo |= *(GraphNodes[*Src].PointsTo))
+ NextWL->insert(&GraphNodes[*Dest]);
+ }
+#endif
+ // since all future elements of the points-to set will be
+ // equivalent to the current ones, the complex constraints
+ // become redundant.
+ //
+ std::list<Constraint>::iterator lk = li; li++;
+#if !FULL_UNIVERSAL
+ // In this case, we can still erase the constraints when the
+ // elements of the points-to sets are referenced by *Dest,
+ // but not when they are referenced by *Src (i.e. for a Load
+ // constraint). This is because if another special variable is
+ // put into the points-to set later, we still need to add the
+ // new edge from that special variable.
+ if( lk->Type != Constraint::Load)
+#endif
+ GraphNodes[CurrNodeIndex].Constraints.erase(lk);
+ } else {
+ const SparseBitVector<> &Solution = CurrPointsTo;
+
+ for (SparseBitVector<>::iterator bi = Solution.begin();
+ bi != Solution.end();
+ ++bi) {
+ CurrMember = *bi;
+
+ // Need to increment the member by K since that is where we are
+ // supposed to copy to/from. Note that in positive weight cycles,
+ // which occur in address taking of fields, K can go past
+ // MaxK[CurrMember] elements, even though that is all it could point
+ // to.
+ if (K > 0 && K > MaxK[CurrMember])
+ continue;
+ else
+ CurrMember = FindNode(CurrMember + K);
+
+ // Add an edge to the graph, so we can just do regular
+ // bitmap ior next time. It may also let us notice a cycle.
+#if !FULL_UNIVERSAL
+ if (*Dest < NumberSpecialNodes)
+ continue;
+#endif
+ if (GraphNodes[*Src].Edges->test_and_set(*Dest))
+ if (GraphNodes[*Dest].PointsTo |= *(GraphNodes[*Src].PointsTo))
+ NextWL->insert(&GraphNodes[*Dest]);
+ }
+ li++;
}
- li++;
}
SparseBitVector<> NewEdges;
SparseBitVector<> ToErase;
unsigned DestVar = *bi;
unsigned Rep = FindNode(DestVar);
- // If we ended up with this node as our destination, or we've already
- // got an edge for the representative, delete the current edge.
- if (Rep == CurrNodeIndex ||
- (Rep != DestVar && NewEdges.test(Rep))) {
- ToErase.set(DestVar);
- continue;
- }
+ // If we ended up with this node as our destination, or we've already
+ // got an edge for the representative, delete the current edge.
+ if (Rep == CurrNodeIndex ||
+ (Rep != DestVar && NewEdges.test(Rep))) {
+ ToErase.set(DestVar);
+ continue;
+ }
- std::pair<unsigned,unsigned> edge(CurrNodeIndex,Rep);
+ std::pair<unsigned,unsigned> edge(CurrNodeIndex,Rep);
// This is where we do lazy cycle detection.
// If this is a cycle candidate (equal points-to sets and this
delete N->OldPointsTo;
delete N->Edges;
}
+ SDTActive = false;
+ SDT.clear();
}
//===----------------------------------------------------------------------===//
DEBUG(PrintNode(SecondNode));
DOUT << "\n";
- // TODO: Handle SDT
+ if (SDTActive)
+ if (SDT[Second] >= 0) {
+ if (SDT[First] < 0)
+ SDT[First] = SDT[Second];
+ else {
+ UniteNodes( FindNode(SDT[First]), FindNode(SDT[Second]) );
+ First = FindNode(First);
+ }
+ }
+
return First;
}
return (N->NodeRep = FindNode(N->NodeRep));
}
+// Find the index into GraphNodes of the node representing Node,
+// don't perform path compression along the way (for Print)
+unsigned Andersens::FindNode(unsigned NodeIndex) const {
+ assert (NodeIndex < GraphNodes.size()
+ && "Attempting to find a node that can't exist");
+ const Node *N = &GraphNodes[NodeIndex];
+ if (N->isRep())
+ return NodeIndex;
+ else
+ return FindNode(N->NodeRep);
+}
+
//===----------------------------------------------------------------------===//
// Debugging Output
//===----------------------------------------------------------------------===//
-void Andersens::PrintNode(Node *N) {
+void Andersens::PrintNode(const Node *N) const {
if (N == &GraphNodes[UniversalSet]) {
cerr << "<universal>";
return;
if (N == &GraphNodes[getObject(V)])
cerr << "<mem>";
}
-void Andersens::PrintConstraint(const Constraint &C) {
+void Andersens::PrintConstraint(const Constraint &C) const {
if (C.Type == Constraint::Store) {
cerr << "*";
if (C.Offset != 0)
cerr << "\n";
}
-void Andersens::PrintConstraints() {
+void Andersens::PrintConstraints() const {
cerr << "Constraints:\n";
for (unsigned i = 0, e = Constraints.size(); i != e; ++i)
PrintConstraint(Constraints[i]);
}
-void Andersens::PrintPointsToGraph() {
+void Andersens::PrintPointsToGraph() const {
cerr << "Points-to graph:\n";
for (unsigned i = 0, e = GraphNodes.size(); i != e; ++i) {
- Node *N = &GraphNodes[i];
- if (FindNode (i) != i) {
+ const Node *N = &GraphNodes[i];
+ if (FindNode(i) != i) {
PrintNode(N);
cerr << "\t--> same as ";
PrintNode(&GraphNodes[FindNode(i)]);
projects / oota-llvm.git / blobdiff