//===- Local.cpp - Compute a local data structure graph for a function ----===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
//
// Compute the local version of the data structure graph for a function. The
// external interface to this file is the DSGraph constructor.
#include "llvm/Analysis/DataStructure.h"
#include "llvm/Analysis/DSGraph.h"
-#include "llvm/iMemory.h"
-#include "llvm/iTerminators.h"
-#include "llvm/iPHINode.h"
-#include "llvm/iOther.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "llvm/GlobalVariable.h"
+#include "llvm/Instructions.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/InstVisitor.h"
#include "llvm/Target/TargetData.h"
-#include "Support/Statistic.h"
-#include "Support/Timer.h"
#include "Support/CommandLine.h"
+#include "Support/Debug.h"
+#include "Support/Timer.h"
// FIXME: This should eventually be a FunctionPass that is automatically
// aggregated into a Pass.
//
#include "llvm/Module.h"
+using namespace llvm;
+
static RegisterAnalysis<LocalDataStructures>
X("datastructure", "Local Data Structure Analysis");
-namespace DS {
- // FIXME: Do something smarter with target data!
- TargetData TD("temp-td");
+static cl::opt<bool>
+TrackIntegersAsPointers("dsa-track-integers",
+ cl::desc("If this is set, track integers as potential pointers"));
+
+namespace llvm {
+namespace DS {
// isPointerType - Return true if this type is big enough to hold a pointer.
bool isPointerType(const Type *Ty) {
if (isa<PointerType>(Ty))
return true;
- else if (Ty->isPrimitiveType() && Ty->isInteger())
+ else if (TrackIntegersAsPointers && Ty->isPrimitiveType() &&Ty->isInteger())
return Ty->getPrimitiveSize() >= PointerSize;
return false;
}
-}
-using namespace DS;
+}}
+using namespace DS;
namespace {
cl::opt<bool>
///
class GraphBuilder : InstVisitor<GraphBuilder> {
DSGraph &G;
- std::vector<DSNode*> &Nodes;
- DSNodeHandle &RetNode; // Node that gets returned...
- hash_map<Value*, DSNodeHandle> &ScalarMap;
- std::vector<DSCallSite> &FunctionCalls;
+ DSNodeHandle *RetNode; // Node that gets returned...
+ DSGraph::ScalarMapTy &ScalarMap;
+ std::vector<DSCallSite> *FunctionCalls;
public:
- GraphBuilder(DSGraph &g, std::vector<DSNode*> &nodes, DSNodeHandle &retNode,
- hash_map<Value*, DSNodeHandle> &SM,
+ GraphBuilder(Function &f, DSGraph &g, DSNodeHandle &retNode,
std::vector<DSCallSite> &fc)
- : G(g), Nodes(nodes), RetNode(retNode), ScalarMap(SM), FunctionCalls(fc) {
+ : G(g), RetNode(&retNode), ScalarMap(G.getScalarMap()),
+ FunctionCalls(&fc) {
// Create scalar nodes for all pointer arguments...
- for (Function::aiterator I = G.getFunction().abegin(),
- E = G.getFunction().aend(); I != E; ++I)
+ for (Function::aiterator I = f.abegin(), E = f.aend(); I != E; ++I)
if (isPointerType(I->getType()))
getValueDest(*I);
- visit(G.getFunction()); // Single pass over the function
+ visit(f); // Single pass over the function
+ }
+
+ // GraphBuilder ctor for working on the globals graph
+ GraphBuilder(DSGraph &g)
+ : G(g), RetNode(0), ScalarMap(G.getScalarMap()), FunctionCalls(0) {
}
+ void mergeInGlobalInitializer(GlobalVariable *GV);
+
private:
// Visitor functions, used to handle each instruction type we encounter...
friend class InstVisitor<GraphBuilder>;
void visitLoadInst(LoadInst &LI);
void visitStoreInst(StoreInst &SI);
void visitCallInst(CallInst &CI);
+ void visitInvokeInst(InvokeInst &II);
void visitSetCondInst(SetCondInst &SCI) {} // SetEQ & friends are ignored
void visitFreeInst(FreeInst &FI);
void visitCastInst(CastInst &CI);
void visitInstruction(Instruction &I);
+ void visitCallSite(CallSite CS);
+
+ void MergeConstantInitIntoNode(DSNodeHandle &NH, Constant *C);
private:
// Helper functions used to implement the visitation functions...
};
}
+using namespace DS;
+
//===----------------------------------------------------------------------===//
// DSGraph constructor - Simply use the GraphBuilder to construct the local
// graph.
-DSGraph::DSGraph(Function &F, DSGraph *GG) : Func(&F), GlobalsGraph(GG) {
+DSGraph::DSGraph(const TargetData &td, Function &F, DSGraph *GG)
+ : GlobalsGraph(GG), TD(td) {
PrintAuxCalls = false;
+
+ DEBUG(std::cerr << " [Loc] Calculating graph for: " << F.getName() << "\n");
+
// Use the graph builder to construct the local version of the graph
- GraphBuilder B(*this, Nodes, RetNode, ScalarMap, FunctionCalls);
+ GraphBuilder B(F, *this, ReturnNodes[&F], FunctionCalls);
#ifndef NDEBUG
Timer::addPeakMemoryMeasurement();
#endif
// Remove all integral constants from the scalarmap!
- for (hash_map<Value*, DSNodeHandle>::iterator I = ScalarMap.begin();
- I != ScalarMap.end();)
+ for (ScalarMapTy::iterator I = ScalarMap.begin(); I != ScalarMap.end();)
if (isa<ConstantIntegral>(I->first)) {
- hash_map<Value*, DSNodeHandle>::iterator J = I++;
+ ScalarMapTy::iterator J = I++;
ScalarMap.erase(J);
} else
++I;
NH = getValueDest(*CE->getOperand(0));
else if (CE->getOpcode() == Instruction::GetElementPtr) {
visitGetElementPtrInst(*CE);
- hash_map<Value*, DSNodeHandle>::iterator I = ScalarMap.find(CE);
+ DSGraph::ScalarMapTy::iterator I = ScalarMap.find(CE);
assert(I != ScalarMap.end() && "GEP didn't get processed right?");
NH = I->second;
} else {
DSNodeHandle Value = getValueDest(*GEP.getOperand(0));
if (Value.getNode() == 0) return;
- unsigned Offset = 0;
+ // As a special case, if all of the index operands of GEP are constant zeros,
+ // handle this just like we handle casts (ie, don't do much).
+ bool AllZeros = true;
+ for (unsigned i = 1, e = GEP.getNumOperands(); i != e; ++i)
+ if (GEP.getOperand(i) !=
+ Constant::getNullValue(GEP.getOperand(i)->getType())) {
+ AllZeros = false;
+ break;
+ }
+
+ // If all of the indices are zero, the result points to the operand without
+ // applying the type.
+ if (AllZeros) {
+ setDestTo(GEP, Value);
+ return;
+ }
+
+
const PointerType *PTy = cast<PointerType>(GEP.getOperand(0)->getType());
const Type *CurTy = PTy->getElementType();
return;
}
+ const TargetData &TD = Value.getNode()->getTargetData();
+
#if 0
// Handle the pointer index specially...
if (GEP.getNumOperands() > 1 &&
#endif
// All of these subscripts are indexing INTO the elements we have...
- for (unsigned i = 2, e = GEP.getNumOperands(); i < e; ++i)
- if (GEP.getOperand(i)->getType() == Type::LongTy) {
- // Get the type indexing into...
- const SequentialType *STy = cast<SequentialType>(CurTy);
- CurTy = STy->getElementType();
+ unsigned Offset = 0;
+ for (gep_type_iterator I = gep_type_begin(GEP), E = gep_type_end(GEP);
+ I != E; ++I)
+ if (const StructType *STy = dyn_cast<StructType>(*I)) {
+ unsigned FieldNo = cast<ConstantUInt>(I.getOperand())->getValue();
+ Offset += TD.getStructLayout(STy)->MemberOffsets[FieldNo];
+ }
+
+
#if 0
+ if (const SequentialType *STy = cast<SequentialType>(*I)) {
+ CurTy = STy->getElementType();
if (ConstantSInt *CS = dyn_cast<ConstantSInt>(GEP.getOperand(i))) {
Offset += CS->getValue()*TD.getTypeSize(CurTy);
} else {
unsigned RawOffset = Offset+Value.getOffset();
// Loop over all of the elements of the array, merging them into the
- // zero'th element.
+ // zeroth element.
for (unsigned i = 1, e = ATy->getNumElements(); i != e; ++i)
// Merge all of the byte components of this array element
for (unsigned j = 0; j != ElSize; ++j)
N->mergeIndexes(RawOffset+j, RawOffset+i*ElSize+j);
}
}
-#endif
- } else if (GEP.getOperand(i)->getType() == Type::UByteTy) {
- unsigned FieldNo = cast<ConstantUInt>(GEP.getOperand(i))->getValue();
- const StructType *STy = cast<StructType>(CurTy);
- Offset += TD.getStructLayout(STy)->MemberOffsets[FieldNo];
- CurTy = STy->getContainedType(FieldNo);
}
+#endif
// Add in the offset calculated...
Value.setOffset(Value.getOffset()+Offset);
// Mark that the node is written to...
Dest.getNode()->setModifiedMarker();
- // Ensure a typerecord exists...
+ // Ensure a type-record exists...
Dest.getNode()->mergeTypeInfo(StoredTy, Dest.getOffset());
// Avoid adding edges from null, or processing non-"pointer" stores
void GraphBuilder::visitReturnInst(ReturnInst &RI) {
if (RI.getNumOperands() && isPointerType(RI.getOperand(0)->getType()))
- RetNode.mergeWith(getValueDest(*RI.getOperand(0)));
+ RetNode->mergeWith(getValueDest(*RI.getOperand(0)));
}
void GraphBuilder::visitCallInst(CallInst &CI) {
+ visitCallSite(&CI);
+}
+
+void GraphBuilder::visitInvokeInst(InvokeInst &II) {
+ visitCallSite(&II);
+}
+
+void GraphBuilder::visitCallSite(CallSite CS) {
+ // Special case handling of certain libc allocation functions here.
+ if (Function *F = CS.getCalledFunction())
+ if (F->isExternal())
+ if (F->getName() == "calloc") {
+ setDestTo(*CS.getInstruction(),
+ createNode()->setHeapNodeMarker()->setModifiedMarker());
+ return;
+ } else if (F->getName() == "realloc") {
+ DSNodeHandle RetNH = getValueDest(*CS.getInstruction());
+ RetNH.mergeWith(getValueDest(**CS.arg_begin()));
+ if (DSNode *N = RetNH.getNode())
+ N->setHeapNodeMarker()->setModifiedMarker()->setReadMarker();
+ return;
+ } else if (F->getName() == "memset") {
+ // Merge the first argument with the return value, and mark the memory
+ // modified.
+ DSNodeHandle RetNH = getValueDest(*CS.getInstruction());
+ RetNH.mergeWith(getValueDest(**CS.arg_begin()));
+ if (DSNode *N = RetNH.getNode())
+ N->setModifiedMarker();
+ return;
+ } else if (F->getName() == "memmove") {
+ // Merge the first & second arguments with the result, and mark the
+ // memory read and modified.
+ DSNodeHandle RetNH = getValueDest(*CS.getInstruction());
+ RetNH.mergeWith(getValueDest(**CS.arg_begin()));
+ RetNH.mergeWith(getValueDest(**(CS.arg_begin()+1)));
+ if (DSNode *N = RetNH.getNode())
+ N->setModifiedMarker()->setReadMarker();
+ return;
+ } else if (F->getName() == "bzero") {
+ // Mark the memory modified.
+ DSNodeHandle H = getValueDest(**CS.arg_begin());
+ if (DSNode *N = H.getNode())
+ N->setModifiedMarker();
+ return;
+ }
+
+
// Set up the return value...
DSNodeHandle RetVal;
- if (isPointerType(CI.getType()))
- RetVal = getValueDest(CI);
+ Instruction *I = CS.getInstruction();
+ if (isPointerType(I->getType()))
+ RetVal = getValueDest(*I);
DSNode *Callee = 0;
- if (DisableDirectCallOpt || !isa<Function>(CI.getOperand(0)))
- Callee = getValueDest(*CI.getOperand(0)).getNode();
+ if (DisableDirectCallOpt || !isa<Function>(CS.getCalledValue())) {
+ Callee = getValueDest(*CS.getCalledValue()).getNode();
+ if (Callee == 0) {
+ std::cerr << "WARNING: Program is calling through a null pointer?\n"
+ << *I;
+ return; // Calling a null pointer?
+ }
+ }
std::vector<DSNodeHandle> Args;
- Args.reserve(CI.getNumOperands()-1);
+ Args.reserve(CS.arg_end()-CS.arg_begin());
// Calculate the arguments vector...
- for (unsigned i = 1, e = CI.getNumOperands(); i != e; ++i)
- if (isPointerType(CI.getOperand(i)->getType()))
- Args.push_back(getValueDest(*CI.getOperand(i)));
+ for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); I != E; ++I)
+ if (isPointerType((*I)->getType()))
+ Args.push_back(getValueDest(**I));
// Add a new function call entry...
if (Callee)
- FunctionCalls.push_back(DSCallSite(CI, RetVal, Callee, Args));
+ FunctionCalls->push_back(DSCallSite(CS, RetVal, Callee, Args));
else
- FunctionCalls.push_back(DSCallSite(CI, RetVal,
- cast<Function>(CI.getOperand(0)), Args));
+ FunctionCalls->push_back(DSCallSite(CS, RetVal, CS.getCalledFunction(),
+ Args));
}
void GraphBuilder::visitFreeInst(FreeInst &FI) {
// LocalDataStructures Implementation
//===----------------------------------------------------------------------===//
+// MergeConstantInitIntoNode - Merge the specified constant into the node
+// pointed to by NH.
+void GraphBuilder::MergeConstantInitIntoNode(DSNodeHandle &NH, Constant *C) {
+ // Ensure a type-record exists...
+ NH.getNode()->mergeTypeInfo(C->getType(), NH.getOffset());
+
+ if (C->getType()->isFirstClassType()) {
+ if (isPointerType(C->getType()))
+ // Avoid adding edges from null, or processing non-"pointer" stores
+ NH.addEdgeTo(getValueDest(*C));
+ return;
+ }
+
+ const TargetData &TD = NH.getNode()->getTargetData();
+
+ if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
+ for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
+ // We don't currently do any indexing for arrays...
+ MergeConstantInitIntoNode(NH, cast<Constant>(CA->getOperand(i)));
+ } else if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
+ const StructLayout *SL = TD.getStructLayout(CS->getType());
+ for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
+ DSNodeHandle NewNH(NH.getNode(), NH.getOffset()+SL->MemberOffsets[i]);
+ MergeConstantInitIntoNode(NewNH, cast<Constant>(CS->getOperand(i)));
+ }
+ } else {
+ assert(0 && "Unknown constant type!");
+ }
+}
+
+void GraphBuilder::mergeInGlobalInitializer(GlobalVariable *GV) {
+ assert(!GV->isExternal() && "Cannot merge in external global!");
+ // Get a node handle to the global node and merge the initializer into it.
+ DSNodeHandle NH = getValueDest(*GV);
+ MergeConstantInitIntoNode(NH, GV->getInitializer());
+}
+
+
bool LocalDataStructures::run(Module &M) {
- GlobalsGraph = new DSGraph();
+ GlobalsGraph = new DSGraph(getAnalysis<TargetData>());
+
+ const TargetData &TD = getAnalysis<TargetData>();
// Calculate all of the graphs...
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isExternal())
- DSInfo.insert(std::make_pair(I, new DSGraph(*I, GlobalsGraph)));
+ DSInfo.insert(std::make_pair(I, new DSGraph(TD, *I, GlobalsGraph)));
+
+ GraphBuilder GGB(*GlobalsGraph);
+
+ // Add initializers for all of the globals to the globals graph...
+ for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
+ if (!I->isExternal())
+ GGB.mergeInGlobalInitializer(I);
+
+ GlobalsGraph->markIncompleteNodes(DSGraph::MarkFormalArgs);
+ GlobalsGraph->removeTriviallyDeadNodes();
return false;
}
// our memory... here...
//
void LocalDataStructures::releaseMemory() {
- for (hash_map<const Function*, DSGraph*>::iterator I = DSInfo.begin(),
- E = DSInfo.end(); I != E; ++I)
- delete I->second;
+ for (hash_map<Function*, DSGraph*>::iterator I = DSInfo.begin(),
+ E = DSInfo.end(); I != E; ++I) {
+ I->second->getReturnNodes().erase(I->first);
+ if (I->second->getReturnNodes().empty())
+ delete I->second;
+ }
// Empty map so next time memory is released, data structures are not
// re-deleted.
delete GlobalsGraph;
GlobalsGraph = 0;
}
+