diff options
Diffstat (limited to 'lib/Transforms/Instrumentation/PathProfiling.cpp')
| -rw-r--r-- | lib/Transforms/Instrumentation/PathProfiling.cpp | 1424 |
1 files changed, 0 insertions, 1424 deletions
diff --git a/lib/Transforms/Instrumentation/PathProfiling.cpp b/lib/Transforms/Instrumentation/PathProfiling.cpp deleted file mode 100644 index 7de7326..0000000 --- a/lib/Transforms/Instrumentation/PathProfiling.cpp +++ /dev/null @@ -1,1424 +0,0 @@ -//===- PathProfiling.cpp - Inserts counters for path profiling ------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This pass instruments functions for Ball-Larus path profiling. Ball-Larus -// profiling converts the CFG into a DAG by replacing backedges with edges -// from entry to the start block and from the end block to exit. The paths -// along the new DAG are enumrated, i.e. each path is given a path number. -// Edges are instrumented to increment the path number register, such that the -// path number register will equal the path number of the path taken at the -// exit. -// -// This file defines classes for building a CFG for use with different stages -// in the Ball-Larus path profiling instrumentation [Ball96]. The -// requirements are formatting the llvm CFG into the Ball-Larus DAG, path -// numbering, finding a spanning tree, moving increments from the spanning -// tree to chords. -// -// Terms: -// DAG - Directed Acyclic Graph. -// Ball-Larus DAG - A CFG with an entry node, an exit node, and backedges -// removed in the following manner. For every backedge -// v->w, insert edge ENTRY->w and edge v->EXIT. -// Path Number - The number corresponding to a specific path through a -// Ball-Larus DAG. -// Spanning Tree - A subgraph, S, is a spanning tree if S covers all -// vertices and is a tree. -// Chord - An edge not in the spanning tree. -// -// [Ball96] -// T. Ball and J. R. Larus. "Efficient Path Profiling." -// International Symposium on Microarchitecture, pages 46-57, 1996. -// http://portal.acm.org/citation.cfm?id=243857 -// -// [Ball94] -// Thomas Ball. "Efficiently Counting Program Events with Support for -// On-line queries." -// ACM Transactions on Programmmg Languages and Systems, Vol 16, No 5, -// September 1994, Pages 1399-1410. -//===----------------------------------------------------------------------===// -#define DEBUG_TYPE "insert-path-profiling" - -#include "llvm/Transforms/Instrumentation.h" -#include "ProfilingUtils.h" -#include "llvm/Analysis/PathNumbering.h" -#include "llvm/IR/Constants.h" -#include "llvm/IR/DerivedTypes.h" -#include "llvm/IR/InstrTypes.h" -#include "llvm/IR/Instructions.h" -#include "llvm/IR/LLVMContext.h" -#include "llvm/IR/Module.h" -#include "llvm/IR/TypeBuilder.h" -#include "llvm/Pass.h" -#include "llvm/Support/CFG.h" -#include "llvm/Support/CommandLine.h" -#include "llvm/Support/Compiler.h" -#include "llvm/Support/Debug.h" -#include "llvm/Support/raw_ostream.h" -#include "llvm/Transforms/Utils/BasicBlockUtils.h" -#include <vector> - -#define HASH_THRESHHOLD 100000 - -using namespace llvm; - -namespace { -class BLInstrumentationNode; -class BLInstrumentationEdge; -class BLInstrumentationDag; - -// --------------------------------------------------------------------------- -// BLInstrumentationNode extends BallLarusNode with member used by the -// instrumentation algortihms. -// --------------------------------------------------------------------------- -class BLInstrumentationNode : public BallLarusNode { -public: - // Creates a new BLInstrumentationNode from a BasicBlock. - BLInstrumentationNode(BasicBlock* BB); - - // Get/sets the Value corresponding to the pathNumber register, - // constant or phinode. Used by the instrumentation code to remember - // path number Values. - Value* getStartingPathNumber(); - void setStartingPathNumber(Value* pathNumber); - - Value* getEndingPathNumber(); - void setEndingPathNumber(Value* pathNumber); - - // Get/set the PHINode Instruction for this node. - PHINode* getPathPHI(); - void setPathPHI(PHINode* pathPHI); - -private: - - Value* _startingPathNumber; // The Value for the current pathNumber. - Value* _endingPathNumber; // The Value for the current pathNumber. - PHINode* _pathPHI; // The PHINode for current pathNumber. -}; - -// -------------------------------------------------------------------------- -// BLInstrumentationEdge extends BallLarusEdge with data about the -// instrumentation that will end up on each edge. -// -------------------------------------------------------------------------- -class BLInstrumentationEdge : public BallLarusEdge { -public: - BLInstrumentationEdge(BLInstrumentationNode* source, - BLInstrumentationNode* target); - - // Sets the target node of this edge. Required to split edges. - void setTarget(BallLarusNode* node); - - // Get/set whether edge is in the spanning tree. - bool isInSpanningTree() const; - void setIsInSpanningTree(bool isInSpanningTree); - - // Get/ set whether this edge will be instrumented with a path number - // initialization. - bool isInitialization() const; - void setIsInitialization(bool isInitialization); - - // Get/set whether this edge will be instrumented with a path counter - // increment. Notice this is incrementing the path counter - // corresponding to the path number register. The path number - // increment is determined by getIncrement(). - bool isCounterIncrement() const; - void setIsCounterIncrement(bool isCounterIncrement); - - // Get/set the path number increment that this edge will be instrumented - // with. This is distinct from the path counter increment and the - // weight. The counter increment counts the number of executions of - // some path, whereas the path number keeps track of which path number - // the program is on. - long getIncrement() const; - void setIncrement(long increment); - - // Get/set whether the edge has been instrumented. - bool hasInstrumentation(); - void setHasInstrumentation(bool hasInstrumentation); - - // Returns the successor number of this edge in the source. - unsigned getSuccessorNumber(); - -private: - // The increment that the code will be instrumented with. - long long _increment; - - // Whether this edge is in the spanning tree. - bool _isInSpanningTree; - - // Whether this edge is an initialiation of the path number. - bool _isInitialization; - - // Whether this edge is a path counter increment. - bool _isCounterIncrement; - - // Whether this edge has been instrumented. - bool _hasInstrumentation; -}; - -// --------------------------------------------------------------------------- -// BLInstrumentationDag extends BallLarusDag with algorithms that -// determine where instrumentation should be placed. -// --------------------------------------------------------------------------- -class BLInstrumentationDag : public BallLarusDag { -public: - BLInstrumentationDag(Function &F); - - // Returns the Exit->Root edge. This edge is required for creating - // directed cycles in the algorithm for moving instrumentation off of - // the spanning tree - BallLarusEdge* getExitRootEdge(); - - // Returns an array of phony edges which mark those nodes - // with function calls - BLEdgeVector getCallPhonyEdges(); - - // Gets/sets the path counter array - GlobalVariable* getCounterArray(); - void setCounterArray(GlobalVariable* c); - - // Calculates the increments for the chords, thereby removing - // instrumentation from the spanning tree edges. Implementation is based - // on the algorithm in Figure 4 of [Ball94] - void calculateChordIncrements(); - - // Updates the state when an edge has been split - void splitUpdate(BLInstrumentationEdge* formerEdge, BasicBlock* newBlock); - - // Calculates a spanning tree of the DAG ignoring cycles. Whichever - // edges are in the spanning tree will not be instrumented, but this - // implementation does not try to minimize the instrumentation overhead - // by trying to find hot edges. - void calculateSpanningTree(); - - // Pushes initialization further down in order to group the first - // increment and initialization. - void pushInitialization(); - - // Pushes the path counter increments up in order to group the last path - // number increment. - void pushCounters(); - - // Removes phony edges from the successor list of the source, and the - // predecessor list of the target. - void unlinkPhony(); - - // Generate dot graph for the function - void generateDotGraph(); - -protected: - // BLInstrumentationDag creates BLInstrumentationNode objects in this - // method overriding the creation of BallLarusNode objects. - // - // Allows subclasses to determine which type of Node is created. - // Override this method to produce subclasses of BallLarusNode if - // necessary. - virtual BallLarusNode* createNode(BasicBlock* BB); - - // BLInstrumentationDag create BLInstrumentationEdges. - // - // Allows subclasses to determine which type of Edge is created. - // Override this method to produce subclasses of BallLarusEdge if - // necessary. Parameters source and target will have been created by - // createNode and can be cast to the subclass of BallLarusNode* - // returned by createNode. - virtual BallLarusEdge* createEdge( - BallLarusNode* source, BallLarusNode* target, unsigned edgeNumber); - -private: - BLEdgeVector _treeEdges; // All edges in the spanning tree. - BLEdgeVector _chordEdges; // All edges not in the spanning tree. - GlobalVariable* _counterArray; // Array to store path counters - - // Removes the edge from the appropriate predecessor and successor lists. - void unlinkEdge(BallLarusEdge* edge); - - // Makes an edge part of the spanning tree. - void makeEdgeSpanning(BLInstrumentationEdge* edge); - - // Pushes initialization and calls itself recursively. - void pushInitializationFromEdge(BLInstrumentationEdge* edge); - - // Pushes path counter increments up recursively. - void pushCountersFromEdge(BLInstrumentationEdge* edge); - - // Depth first algorithm for determining the chord increments.f - void calculateChordIncrementsDfs( - long weight, BallLarusNode* v, BallLarusEdge* e); - - // Determines the relative direction of two edges. - int calculateChordIncrementsDir(BallLarusEdge* e, BallLarusEdge* f); -}; - -// --------------------------------------------------------------------------- -// PathProfiler is a module pass which instruments path profiling instructions -// --------------------------------------------------------------------------- -class PathProfiler : public ModulePass { -private: - // Current context for multi threading support. - LLVMContext* Context; - - // Which function are we currently instrumenting - unsigned currentFunctionNumber; - - // The function prototype in the profiling runtime for incrementing a - // single path counter in a hash table. - Constant* llvmIncrementHashFunction; - Constant* llvmDecrementHashFunction; - - // Instruments each function with path profiling. 'main' is instrumented - // with code to save the profile to disk. - bool runOnModule(Module &M); - - // Analyzes the function for Ball-Larus path profiling, and inserts code. - void runOnFunction(std::vector<Constant*> &ftInit, Function &F, Module &M); - - // Creates an increment constant representing incr. - ConstantInt* createIncrementConstant(long incr, int bitsize); - - // Creates an increment constant representing the value in - // edge->getIncrement(). - ConstantInt* createIncrementConstant(BLInstrumentationEdge* edge); - - // Finds the insertion point after pathNumber in block. PathNumber may - // be NULL. - BasicBlock::iterator getInsertionPoint( - BasicBlock* block, Value* pathNumber); - - // Inserts source's pathNumber Value* into target. Target may or may not - // have multiple predecessors, and may or may not have its phiNode - // initalized. - void pushValueIntoNode( - BLInstrumentationNode* source, BLInstrumentationNode* target); - - // Inserts source's pathNumber Value* into the appropriate slot of - // target's phiNode. - void pushValueIntoPHI( - BLInstrumentationNode* target, BLInstrumentationNode* source); - - // The Value* in node, oldVal, is updated with a Value* correspodning to - // oldVal + addition. - void insertNumberIncrement(BLInstrumentationNode* node, Value* addition, - bool atBeginning); - - // Creates a counter increment in the given node. The Value* in node is - // taken as the index into a hash table. - void insertCounterIncrement( - Value* incValue, - BasicBlock::iterator insertPoint, - BLInstrumentationDag* dag, - bool increment = true); - - // A PHINode is created in the node, and its values initialized to -1U. - void preparePHI(BLInstrumentationNode* node); - - // Inserts instrumentation for the given edge - // - // Pre: The edge's source node has pathNumber set if edge is non zero - // path number increment. - // - // Post: Edge's target node has a pathNumber set to the path number Value - // corresponding to the value of the path register after edge's - // execution. - void insertInstrumentationStartingAt( - BLInstrumentationEdge* edge, - BLInstrumentationDag* dag); - - // If this edge is a critical edge, then inserts a node at this edge. - // This edge becomes the first edge, and a new BallLarusEdge is created. - bool splitCritical(BLInstrumentationEdge* edge, BLInstrumentationDag* dag); - - // Inserts instrumentation according to the marked edges in dag. Phony - // edges must be unlinked from the DAG, but accessible from the - // backedges. Dag must have initializations, path number increments, and - // counter increments present. - // - // Counter storage is created here. - void insertInstrumentation( BLInstrumentationDag& dag, Module &M); - -public: - static char ID; // Pass identification, replacement for typeid - PathProfiler() : ModulePass(ID) { - initializePathProfilerPass(*PassRegistry::getPassRegistry()); - } - - virtual const char *getPassName() const { - return "Path Profiler"; - } -}; -} // end anonymous namespace - -// Should we print the dot-graphs -static cl::opt<bool> DotPathDag("path-profile-pathdag", cl::Hidden, - cl::desc("Output the path profiling DAG for each function.")); - -// Register the path profiler as a pass -char PathProfiler::ID = 0; -INITIALIZE_PASS(PathProfiler, "insert-path-profiling", - "Insert instrumentation for Ball-Larus path profiling", - false, false) - -ModulePass *llvm::createPathProfilerPass() { return new PathProfiler(); } - -namespace llvm { - class PathProfilingFunctionTable {}; - - // Type for global array storing references to hashes or arrays - template<bool xcompile> class TypeBuilder<PathProfilingFunctionTable, - xcompile> { - public: - static StructType *get(LLVMContext& C) { - return( StructType::get( - TypeBuilder<types::i<32>, xcompile>::get(C), // type - TypeBuilder<types::i<32>, xcompile>::get(C), // array size - TypeBuilder<types::i<8>*, xcompile>::get(C), // array/hash ptr - NULL)); - } - }; - - typedef TypeBuilder<PathProfilingFunctionTable, true> - ftEntryTypeBuilder; - - // BallLarusEdge << operator overloading - raw_ostream& operator<<(raw_ostream& os, - const BLInstrumentationEdge& edge) - LLVM_ATTRIBUTE_USED; - raw_ostream& operator<<(raw_ostream& os, - const BLInstrumentationEdge& edge) { - os << "[" << edge.getSource()->getName() << " -> " - << edge.getTarget()->getName() << "] init: " - << (edge.isInitialization() ? "yes" : "no") - << " incr:" << edge.getIncrement() << " cinc: " - << (edge.isCounterIncrement() ? "yes" : "no"); - return(os); - } -} - -// Creates a new BLInstrumentationNode from a BasicBlock. -BLInstrumentationNode::BLInstrumentationNode(BasicBlock* BB) : - BallLarusNode(BB), - _startingPathNumber(NULL), _endingPathNumber(NULL), _pathPHI(NULL) {} - -// Constructor for BLInstrumentationEdge. -BLInstrumentationEdge::BLInstrumentationEdge(BLInstrumentationNode* source, - BLInstrumentationNode* target) - : BallLarusEdge(source, target, 0), - _increment(0), _isInSpanningTree(false), _isInitialization(false), - _isCounterIncrement(false), _hasInstrumentation(false) {} - -// Sets the target node of this edge. Required to split edges. -void BLInstrumentationEdge::setTarget(BallLarusNode* node) { - _target = node; -} - -// Returns whether this edge is in the spanning tree. -bool BLInstrumentationEdge::isInSpanningTree() const { - return(_isInSpanningTree); -} - -// Sets whether this edge is in the spanning tree. -void BLInstrumentationEdge::setIsInSpanningTree(bool isInSpanningTree) { - _isInSpanningTree = isInSpanningTree; -} - -// Returns whether this edge will be instrumented with a path number -// initialization. -bool BLInstrumentationEdge::isInitialization() const { - return(_isInitialization); -} - -// Sets whether this edge will be instrumented with a path number -// initialization. -void BLInstrumentationEdge::setIsInitialization(bool isInitialization) { - _isInitialization = isInitialization; -} - -// Returns whether this edge will be instrumented with a path counter -// increment. Notice this is incrementing the path counter -// corresponding to the path number register. The path number -// increment is determined by getIncrement(). -bool BLInstrumentationEdge::isCounterIncrement() const { - return(_isCounterIncrement); -} - -// Sets whether this edge will be instrumented with a path counter -// increment. -void BLInstrumentationEdge::setIsCounterIncrement(bool isCounterIncrement) { - _isCounterIncrement = isCounterIncrement; -} - -// Gets the path number increment that this edge will be instrumented -// with. This is distinct from the path counter increment and the -// weight. The counter increment is counts the number of executions of -// some path, whereas the path number keeps track of which path number -// the program is on. -long BLInstrumentationEdge::getIncrement() const { - return(_increment); -} - -// Set whether this edge will be instrumented with a path number -// increment. -void BLInstrumentationEdge::setIncrement(long increment) { - _increment = increment; -} - -// True iff the edge has already been instrumented. -bool BLInstrumentationEdge::hasInstrumentation() { - return(_hasInstrumentation); -} - -// Set whether this edge has been instrumented. -void BLInstrumentationEdge::setHasInstrumentation(bool hasInstrumentation) { - _hasInstrumentation = hasInstrumentation; -} - -// Returns the successor number of this edge in the source. -unsigned BLInstrumentationEdge::getSuccessorNumber() { - BallLarusNode* sourceNode = getSource(); - BallLarusNode* targetNode = getTarget(); - BasicBlock* source = sourceNode->getBlock(); - BasicBlock* target = targetNode->getBlock(); - - if(source == NULL || target == NULL) - return(0); - - TerminatorInst* terminator = source->getTerminator(); - - unsigned i; - for(i=0; i < terminator->getNumSuccessors(); i++) { - if(terminator->getSuccessor(i) == target) - break; - } - - return(i); -} - -// BLInstrumentationDag constructor initializes a DAG for the given Function. -BLInstrumentationDag::BLInstrumentationDag(Function &F) : BallLarusDag(F), - _counterArray(0) { -} - -// Returns the Exit->Root edge. This edge is required for creating -// directed cycles in the algorithm for moving instrumentation off of -// the spanning tree -BallLarusEdge* BLInstrumentationDag::getExitRootEdge() { - BLEdgeIterator erEdge = getExit()->succBegin(); - return(*erEdge); -} - -BLEdgeVector BLInstrumentationDag::getCallPhonyEdges () { - BLEdgeVector callEdges; - - for( BLEdgeIterator edge = _edges.begin(), end = _edges.end(); - edge != end; edge++ ) { - if( (*edge)->getType() == BallLarusEdge::CALLEDGE_PHONY ) - callEdges.push_back(*edge); - } - - return callEdges; -} - -// Gets the path counter array -GlobalVariable* BLInstrumentationDag::getCounterArray() { - return _counterArray; -} - -void BLInstrumentationDag::setCounterArray(GlobalVariable* c) { - _counterArray = c; -} - -// Calculates the increment for the chords, thereby removing -// instrumentation from the spanning tree edges. Implementation is based on -// the algorithm in Figure 4 of [Ball94] -void BLInstrumentationDag::calculateChordIncrements() { - calculateChordIncrementsDfs(0, getRoot(), NULL); - - BLInstrumentationEdge* chord; - for(BLEdgeIterator chordEdge = _chordEdges.begin(), - end = _chordEdges.end(); chordEdge != end; chordEdge++) { - chord = (BLInstrumentationEdge*) *chordEdge; - chord->setIncrement(chord->getIncrement() + chord->getWeight()); - } -} - -// Updates the state when an edge has been split -void BLInstrumentationDag::splitUpdate(BLInstrumentationEdge* formerEdge, - BasicBlock* newBlock) { - BallLarusNode* oldTarget = formerEdge->getTarget(); - BallLarusNode* newNode = addNode(newBlock); - formerEdge->setTarget(newNode); - newNode->addPredEdge(formerEdge); - - DEBUG(dbgs() << " Edge split: " << *formerEdge << "\n"); - - oldTarget->removePredEdge(formerEdge); - BallLarusEdge* newEdge = addEdge(newNode, oldTarget,0); - - if( formerEdge->getType() == BallLarusEdge::BACKEDGE || - formerEdge->getType() == BallLarusEdge::SPLITEDGE) { - newEdge->setType(formerEdge->getType()); - newEdge->setPhonyRoot(formerEdge->getPhonyRoot()); - newEdge->setPhonyExit(formerEdge->getPhonyExit()); - formerEdge->setType(BallLarusEdge::NORMAL); - formerEdge->setPhonyRoot(NULL); - formerEdge->setPhonyExit(NULL); - } -} - -// Calculates a spanning tree of the DAG ignoring cycles. Whichever -// edges are in the spanning tree will not be instrumented, but this -// implementation does not try to minimize the instrumentation overhead -// by trying to find hot edges. -void BLInstrumentationDag::calculateSpanningTree() { - std::stack<BallLarusNode*> dfsStack; - - for(BLNodeIterator nodeIt = _nodes.begin(), end = _nodes.end(); - nodeIt != end; nodeIt++) { - (*nodeIt)->setColor(BallLarusNode::WHITE); - } - - dfsStack.push(getRoot()); - while(dfsStack.size() > 0) { - BallLarusNode* node = dfsStack.top(); - dfsStack.pop(); - - if(node->getColor() == BallLarusNode::WHITE) - continue; - - BallLarusNode* nextNode; - bool forward = true; - BLEdgeIterator succEnd = node->succEnd(); - - node->setColor(BallLarusNode::WHITE); - // first iterate over successors then predecessors - for(BLEdgeIterator edge = node->succBegin(), predEnd = node->predEnd(); - edge != predEnd; edge++) { - if(edge == succEnd) { - edge = node->predBegin(); - forward = false; - } - - // Ignore split edges - if ((*edge)->getType() == BallLarusEdge::SPLITEDGE) - continue; - - nextNode = forward? (*edge)->getTarget(): (*edge)->getSource(); - if(nextNode->getColor() != BallLarusNode::WHITE) { - nextNode->setColor(BallLarusNode::WHITE); - makeEdgeSpanning((BLInstrumentationEdge*)(*edge)); - } - } - } - - for(BLEdgeIterator edge = _edges.begin(), end = _edges.end(); - edge != end; edge++) { - BLInstrumentationEdge* instEdge = (BLInstrumentationEdge*) (*edge); - // safe since createEdge is overriden - if(!instEdge->isInSpanningTree() && (*edge)->getType() - != BallLarusEdge::SPLITEDGE) - _chordEdges.push_back(instEdge); - } -} - -// Pushes initialization further down in order to group the first -// increment and initialization. -void BLInstrumentationDag::pushInitialization() { - BLInstrumentationEdge* exitRootEdge = - (BLInstrumentationEdge*) getExitRootEdge(); - exitRootEdge->setIsInitialization(true); - pushInitializationFromEdge(exitRootEdge); -} - -// Pushes the path counter increments up in order to group the last path -// number increment. -void BLInstrumentationDag::pushCounters() { - BLInstrumentationEdge* exitRootEdge = - (BLInstrumentationEdge*) getExitRootEdge(); - exitRootEdge->setIsCounterIncrement(true); - pushCountersFromEdge(exitRootEdge); -} - -// Removes phony edges from the successor list of the source, and the -// predecessor list of the target. -void BLInstrumentationDag::unlinkPhony() { - BallLarusEdge* edge; - - for(BLEdgeIterator next = _edges.begin(), - end = _edges.end(); next != end; next++) { - edge = (*next); - - if( edge->getType() == BallLarusEdge::BACKEDGE_PHONY || - edge->getType() == BallLarusEdge::SPLITEDGE_PHONY || - edge->getType() == BallLarusEdge::CALLEDGE_PHONY ) { - unlinkEdge(edge); - } - } -} - -// Generate a .dot graph to represent the DAG and pathNumbers -void BLInstrumentationDag::generateDotGraph() { - std::string errorInfo; - std::string functionName = getFunction().getName().str(); - std::string filename = "pathdag." + functionName + ".dot"; - - DEBUG (dbgs() << "Writing '" << filename << "'...\n"); - raw_fd_ostream dotFile(filename.c_str(), errorInfo); - - if (!errorInfo.empty()) { - errs() << "Error opening '" << filename.c_str() <<"' for writing!"; - errs() << "\n"; - return; - } - - dotFile << "digraph " << functionName << " {\n"; - - for( BLEdgeIterator edge = _edges.begin(), end = _edges.end(); - edge != end; edge++) { - std::string sourceName = (*edge)->getSource()->getName(); - std::string targetName = (*edge)->getTarget()->getName(); - - dotFile << "\t\"" << sourceName.c_str() << "\" -> \"" - << targetName.c_str() << "\" "; - - long inc = ((BLInstrumentationEdge*)(*edge))->getIncrement(); - - switch( (*edge)->getType() ) { - case BallLarusEdge::NORMAL: - dotFile << "[label=" << inc << "] [color=black];\n"; - break; - - case BallLarusEdge::BACKEDGE: - dotFile << "[color=cyan];\n"; - break; - - case BallLarusEdge::BACKEDGE_PHONY: - dotFile << "[label=" << inc - << "] [color=blue];\n"; - break; - - case BallLarusEdge::SPLITEDGE: - dotFile << "[color=violet];\n"; - break; - - case BallLarusEdge::SPLITEDGE_PHONY: - dotFile << "[label=" << inc << "] [color=red];\n"; - break; - - case BallLarusEdge::CALLEDGE_PHONY: - dotFile << "[label=" << inc << "] [color=green];\n"; - break; - } - } - - dotFile << "}\n"; -} - -// Allows subclasses to determine which type of Node is created. -// Override this method to produce subclasses of BallLarusNode if -// necessary. The destructor of BallLarusDag will call free on each pointer -// created. -BallLarusNode* BLInstrumentationDag::createNode(BasicBlock* BB) { - return( new BLInstrumentationNode(BB) ); -} - -// Allows subclasses to determine which type of Edge is created. -// Override this method to produce subclasses of BallLarusEdge if -// necessary. The destructor of BallLarusDag will call free on each pointer -// created. -BallLarusEdge* BLInstrumentationDag::createEdge(BallLarusNode* source, - BallLarusNode* target, unsigned edgeNumber) { - // One can cast from BallLarusNode to BLInstrumentationNode since createNode - // is overriden to produce BLInstrumentationNode. - return( new BLInstrumentationEdge((BLInstrumentationNode*)source, - (BLInstrumentationNode*)target) ); -} - -// Sets the Value corresponding to the pathNumber register, constant, -// or phinode. Used by the instrumentation code to remember path -// number Values. -Value* BLInstrumentationNode::getStartingPathNumber(){ - return(_startingPathNumber); -} - -// Sets the Value of the pathNumber. Used by the instrumentation code. -void BLInstrumentationNode::setStartingPathNumber(Value* pathNumber) { - DEBUG(dbgs() << " SPN-" << getName() << " <-- " << (pathNumber ? - pathNumber->getName() : - "unused") << "\n"); - _startingPathNumber = pathNumber; -} - -Value* BLInstrumentationNode::getEndingPathNumber(){ - return(_endingPathNumber); -} - -void BLInstrumentationNode::setEndingPathNumber(Value* pathNumber) { - DEBUG(dbgs() << " EPN-" << getName() << " <-- " - << (pathNumber ? pathNumber->getName() : "unused") << "\n"); - _endingPathNumber = pathNumber; -} - -// Get the PHINode Instruction for this node. Used by instrumentation -// code. -PHINode* BLInstrumentationNode::getPathPHI() { - return(_pathPHI); -} - -// Set the PHINode Instruction for this node. Used by instrumentation -// code. -void BLInstrumentationNode::setPathPHI(PHINode* pathPHI) { - _pathPHI = pathPHI; -} - -// Removes the edge from the appropriate predecessor and successor -// lists. -void BLInstrumentationDag::unlinkEdge(BallLarusEdge* edge) { - if(edge == getExitRootEdge()) - DEBUG(dbgs() << " Removing exit->root edge\n"); - - edge->getSource()->removeSuccEdge(edge); - edge->getTarget()->removePredEdge(edge); -} - -// Makes an edge part of the spanning tree. -void BLInstrumentationDag::makeEdgeSpanning(BLInstrumentationEdge* edge) { - edge->setIsInSpanningTree(true); - _treeEdges.push_back(edge); -} - -// Pushes initialization and calls itself recursively. -void BLInstrumentationDag::pushInitializationFromEdge( - BLInstrumentationEdge* edge) { - BallLarusNode* target; - - target = edge->getTarget(); - if( target->getNumberPredEdges() > 1 || target == getExit() ) { - return; - } else { - for(BLEdgeIterator next = target->succBegin(), - end = target->succEnd(); next != end; next++) { - BLInstrumentationEdge* intoEdge = (BLInstrumentationEdge*) *next; - - // Skip split edges - if (intoEdge->getType() == BallLarusEdge::SPLITEDGE) - continue; - - intoEdge->setIncrement(intoEdge->getIncrement() + - edge->getIncrement()); - intoEdge->setIsInitialization(true); - pushInitializationFromEdge(intoEdge); - } - - edge->setIncrement(0); - edge->setIsInitialization(false); - } -} - -// Pushes path counter increments up recursively. -void BLInstrumentationDag::pushCountersFromEdge(BLInstrumentationEdge* edge) { - BallLarusNode* source; - - source = edge->getSource(); - if(source->getNumberSuccEdges() > 1 || source == getRoot() - || edge->isInitialization()) { - return; - } else { - for(BLEdgeIterator previous = source->predBegin(), - end = source->predEnd(); previous != end; previous++) { - BLInstrumentationEdge* fromEdge = (BLInstrumentationEdge*) *previous; - - // Skip split edges - if (fromEdge->getType() == BallLarusEdge::SPLITEDGE) - continue; - - fromEdge->setIncrement(fromEdge->getIncrement() + - edge->getIncrement()); - fromEdge->setIsCounterIncrement(true); - pushCountersFromEdge(fromEdge); - } - - edge->setIncrement(0); - edge->setIsCounterIncrement(false); - } -} - -// Depth first algorithm for determining the chord increments. -void BLInstrumentationDag::calculateChordIncrementsDfs(long weight, - BallLarusNode* v, BallLarusEdge* e) { - BLInstrumentationEdge* f; - - for(BLEdgeIterator treeEdge = _treeEdges.begin(), - end = _treeEdges.end(); treeEdge != end; treeEdge++) { - f = (BLInstrumentationEdge*) *treeEdge; - if(e != f && v == f->getTarget()) { - calculateChordIncrementsDfs( - calculateChordIncrementsDir(e,f)*(weight) + - f->getWeight(), f->getSource(), f); - } - if(e != f && v == f->getSource()) { - calculateChordIncrementsDfs( - calculateChordIncrementsDir(e,f)*(weight) + - f->getWeight(), f->getTarget(), f); - } - } - - for(BLEdgeIterator chordEdge = _chordEdges.begin(), - end = _chordEdges.end(); chordEdge != end; chordEdge++) { - f = (BLInstrumentationEdge*) *chordEdge; - if(v == f->getSource() || v == f->getTarget()) { - f->setIncrement(f->getIncrement() + - calculateChordIncrementsDir(e,f)*weight); - } - } -} - -// Determines the relative direction of two edges. -int BLInstrumentationDag::calculateChordIncrementsDir(BallLarusEdge* e, - BallLarusEdge* f) { - if( e == NULL) - return(1); - else if(e->getSource() == f->getTarget() - || e->getTarget() == f->getSource()) - return(1); - - return(-1); -} - -// Creates an increment constant representing incr. -ConstantInt* PathProfiler::createIncrementConstant(long incr, - int bitsize) { - return(ConstantInt::get(IntegerType::get(*Context, 32), incr)); -} - -// Creates an increment constant representing the value in -// edge->getIncrement(). -ConstantInt* PathProfiler::createIncrementConstant( - BLInstrumentationEdge* edge) { - return(createIncrementConstant(edge->getIncrement(), 32)); -} - -// Finds the insertion point after pathNumber in block. PathNumber may -// be NULL. -BasicBlock::iterator PathProfiler::getInsertionPoint(BasicBlock* block, Value* - pathNumber) { - if(pathNumber == NULL || isa<ConstantInt>(pathNumber) - || (((Instruction*)(pathNumber))->getParent()) != block) { - return(block->getFirstInsertionPt()); - } else { - Instruction* pathNumberInst = (Instruction*) (pathNumber); - BasicBlock::iterator insertPoint; - BasicBlock::iterator end = block->end(); - - for(insertPoint = block->begin(); - insertPoint != end; insertPoint++) { - Instruction* insertInst = &(*insertPoint); - - if(insertInst == pathNumberInst) - return(++insertPoint); - } - - return(insertPoint); - } -} - -// A PHINode is created in the node, and its values initialized to -1U. -void PathProfiler::preparePHI(BLInstrumentationNode* node) { - BasicBlock* block = node->getBlock(); - BasicBlock::iterator insertPoint = block->getFirstInsertionPt(); - pred_iterator PB = pred_begin(node->getBlock()), - PE = pred_end(node->getBlock()); - PHINode* phi = PHINode::Create(Type::getInt32Ty(*Context), - std::distance(PB, PE), "pathNumber", - insertPoint ); - node->setPathPHI(phi); - node->setStartingPathNumber(phi); - node->setEndingPathNumber(phi); - - for(pred_iterator predIt = PB; predIt != PE; predIt++) { - BasicBlock* pred = (*predIt); - - if(pred != NULL) - phi->addIncoming(createIncrementConstant((long)-1, 32), pred); - } -} - -// Inserts source's pathNumber Value* into target. Target may or may not -// have multiple predecessors, and may or may not have its phiNode -// initalized. -void PathProfiler::pushValueIntoNode(BLInstrumentationNode* source, - BLInstrumentationNode* target) { - if(target->getBlock() == NULL) - return; - - - if(target->getNumberPredEdges() <= 1) { - assert(target->getStartingPathNumber() == NULL && - "Target already has path number"); - target->setStartingPathNumber(source->getEndingPathNumber()); - target->setEndingPathNumber(source->getEndingPathNumber()); - DEBUG(dbgs() << " Passing path number" - << (source->getEndingPathNumber() ? "" : " (null)") - << " value through.\n"); - } else { - if(target->getPathPHI() == NULL) { - DEBUG(dbgs() << " Initializing PHI node for block '" - << target->getName() << "'\n"); - preparePHI(target); - } - pushValueIntoPHI(target, source); - DEBUG(dbgs() << " Passing number value into PHI for block '" - << target->getName() << "'\n"); - } -} - -// Inserts source's pathNumber Value* into the appropriate slot of -// target's phiNode. -void PathProfiler::pushValueIntoPHI(BLInstrumentationNode* target, - BLInstrumentationNode* source) { - PHINode* phi = target->getPathPHI(); - assert(phi != NULL && " Tried to push value into node with PHI, but node" - " actually had no PHI."); - phi->removeIncomingValue(source->getBlock(), false); - phi->addIncoming(source->getEndingPathNumber(), source->getBlock()); -} - -// The Value* in node, oldVal, is updated with a Value* correspodning to -// oldVal + addition. -void PathProfiler::insertNumberIncrement(BLInstrumentationNode* node, - Value* addition, bool atBeginning) { - BasicBlock* block = node->getBlock(); - assert(node->getStartingPathNumber() != NULL); - assert(node->getEndingPathNumber() != NULL); - - BasicBlock::iterator insertPoint; - - if( atBeginning ) - insertPoint = block->getFirstInsertionPt(); - else - insertPoint = block->getTerminator(); - - DEBUG(errs() << " Creating addition instruction.\n"); - Value* newpn = BinaryOperator::Create(Instruction::Add, - node->getStartingPathNumber(), - addition, "pathNumber", insertPoint); - - node->setEndingPathNumber(newpn); - - if( atBeginning ) - node->setStartingPathNumber(newpn); -} - -// Creates a counter increment in the given node. The Value* in node is -// taken as the index into an array or hash table. The hash table access -// is a call to the runtime. -void PathProfiler::insertCounterIncrement(Value* incValue, - BasicBlock::iterator insertPoint, - BLInstrumentationDag* dag, - bool increment) { - // Counter increment for array - if( dag->getNumberOfPaths() <= HASH_THRESHHOLD ) { - // Get pointer to the array location - std::vector<Value*> gepIndices(2); - gepIndices[0] = Constant::getNullValue(Type::getInt32Ty(*Context)); - gepIndices[1] = incValue; - - GetElementPtrInst* pcPointer = - GetElementPtrInst::Create(dag->getCounterArray(), gepIndices, - "counterInc", insertPoint); - - // Load from the array - call it oldPC - LoadInst* oldPc = new LoadInst(pcPointer, "oldPC", insertPoint); - - // Test to see whether adding 1 will overflow the counter - ICmpInst* isMax = new ICmpInst(insertPoint, CmpInst::ICMP_ULT, oldPc, - createIncrementConstant(0xffffffff, 32), - "isMax"); - - // Select increment for the path counter based on overflow - SelectInst* inc = - SelectInst::Create( isMax, createIncrementConstant(increment?1:-1,32), - createIncrementConstant(0,32), - "pathInc", insertPoint); - - // newPc = oldPc + inc - BinaryOperator* newPc = BinaryOperator::Create(Instruction::Add, - oldPc, inc, "newPC", - insertPoint); - - // Store back in to the array - new StoreInst(newPc, pcPointer, insertPoint); - } else { // Counter increment for hash - std::vector<Value*> args(2); - args[0] = ConstantInt::get(Type::getInt32Ty(*Context), - currentFunctionNumber); - args[1] = incValue; - - CallInst::Create( - increment ? llvmIncrementHashFunction : llvmDecrementHashFunction, - args, "", insertPoint); - } -} - -// Inserts instrumentation for the given edge -// -// Pre: The edge's source node has pathNumber set if edge is non zero -// path number increment. -// -// Post: Edge's target node has a pathNumber set to the path number Value -// corresponding to the value of the path register after edge's -// execution. -// -// FIXME: This should be reworked so it's not recursive. -void PathProfiler::insertInstrumentationStartingAt(BLInstrumentationEdge* edge, - BLInstrumentationDag* dag) { - // Mark the edge as instrumented - edge->setHasInstrumentation(true); - DEBUG(dbgs() << "\nInstrumenting edge: " << (*edge) << "\n"); - - // create a new node for this edge's instrumentation - splitCritical(edge, dag); - - BLInstrumentationNode* sourceNode = (BLInstrumentationNode*)edge->getSource(); - BLInstrumentationNode* targetNode = (BLInstrumentationNode*)edge->getTarget(); - BLInstrumentationNode* instrumentNode; - BLInstrumentationNode* nextSourceNode; - - bool atBeginning = false; - - // Source node has only 1 successor so any information can be simply - // inserted in to it without splitting - if( sourceNode->getBlock() && sourceNode->getNumberSuccEdges() <= 1) { - DEBUG(dbgs() << " Potential instructions to be placed in: " - << sourceNode->getName() << " (at end)\n"); - instrumentNode = sourceNode; - nextSourceNode = targetNode; // ... since we never made any new nodes - } - - // The target node only has one predecessor, so we can safely insert edge - // instrumentation into it. If there was splitting, it must have been - // successful. - else if( targetNode->getNumberPredEdges() == 1 ) { - DEBUG(dbgs() << " Potential instructions to be placed in: " - << targetNode->getName() << " (at beginning)\n"); - pushValueIntoNode(sourceNode, targetNode); - instrumentNode = targetNode; - nextSourceNode = NULL; // ... otherwise we'll just keep splitting - atBeginning = true; - } - - // Somehow, splitting must have failed. - else { - errs() << "Instrumenting could not split a critical edge.\n"; - DEBUG(dbgs() << " Couldn't split edge " << (*edge) << ".\n"); - return; - } - - // Insert instrumentation if this is a back or split edge - if( edge->getType() == BallLarusEdge::BACKEDGE || - edge->getType() == BallLarusEdge::SPLITEDGE ) { - BLInstrumentationEdge* top = - (BLInstrumentationEdge*) edge->getPhonyRoot(); - BLInstrumentationEdge* bottom = - (BLInstrumentationEdge*) edge->getPhonyExit(); - - assert( top->isInitialization() && " Top phony edge did not" - " contain a path number initialization."); - assert( bottom->isCounterIncrement() && " Bottom phony edge" - " did not contain a path counter increment."); - - // split edge has yet to be initialized - if( !instrumentNode->getEndingPathNumber() ) { - instrumentNode->setStartingPathNumber(createIncrementConstant(0,32)); - instrumentNode->setEndingPathNumber(createIncrementConstant(0,32)); - } - - BasicBlock::iterator insertPoint = atBeginning ? - instrumentNode->getBlock()->getFirstInsertionPt() : - instrumentNode->getBlock()->getTerminator(); - - // add information from the bottom edge, if it exists - if( bottom->getIncrement() ) { - Value* newpn = - BinaryOperator::Create(Instruction::Add, - instrumentNode->getStartingPathNumber(), - createIncrementConstant(bottom), - "pathNumber", insertPoint); - instrumentNode->setEndingPathNumber(newpn); - } - - insertCounterIncrement(instrumentNode->getEndingPathNumber(), - insertPoint, dag); - - if( atBeginning ) - instrumentNode->setStartingPathNumber(createIncrementConstant(top)); - - instrumentNode->setEndingPathNumber(createIncrementConstant(top)); - - // Check for path counter increments - if( top->isCounterIncrement() ) { - insertCounterIncrement(instrumentNode->getEndingPathNumber(), - instrumentNode->getBlock()->getTerminator(),dag); - instrumentNode->setEndingPathNumber(0); - } - } - - // Insert instrumentation if this is a normal edge - else { - BasicBlock::iterator insertPoint = atBeginning ? - instrumentNode->getBlock()->getFirstInsertionPt() : - instrumentNode->getBlock()->getTerminator(); - - if( edge->isInitialization() ) { // initialize path number - instrumentNode->setEndingPathNumber(createIncrementConstant(edge)); - } else if( edge->getIncrement() ) {// increment path number - Value* newpn = - BinaryOperator::Create(Instruction::Add, - instrumentNode->getStartingPathNumber(), - createIncrementConstant(edge), - "pathNumber", insertPoint); - instrumentNode->setEndingPathNumber(newpn); - - if( atBeginning ) - instrumentNode->setStartingPathNumber(newpn); - } - - // Check for path counter increments - if( edge->isCounterIncrement() ) { - insertCounterIncrement(instrumentNode->getEndingPathNumber(), - insertPoint, dag); - instrumentNode->setEndingPathNumber(0); - } - } - - // Push it along - if (nextSourceNode && instrumentNode->getEndingPathNumber()) - pushValueIntoNode(instrumentNode, nextSourceNode); - - // Add all the successors - for( BLEdgeIterator next = targetNode->succBegin(), - end = targetNode->succEnd(); next != end; next++ ) { - // So long as it is un-instrumented, add it to the list - if( !((BLInstrumentationEdge*)(*next))->hasInstrumentation() ) - insertInstrumentationStartingAt((BLInstrumentationEdge*)*next,dag); - else - DEBUG(dbgs() << " Edge " << *(BLInstrumentationEdge*)(*next) - << " already instrumented.\n"); - } -} - -// Inserts instrumentation according to the marked edges in dag. Phony edges -// must be unlinked from the DAG, but accessible from the backedges. Dag -// must have initializations, path number increments, and counter increments -// present. -// -// Counter storage is created here. -void PathProfiler::insertInstrumentation( - BLInstrumentationDag& dag, Module &M) { - - BLInstrumentationEdge* exitRootEdge = - (BLInstrumentationEdge*) dag.getExitRootEdge(); - insertInstrumentationStartingAt(exitRootEdge, &dag); - - // Iterate through each call edge and apply the appropriate hash increment - // and decrement functions - BLEdgeVector callEdges = dag.getCallPhonyEdges(); - for( BLEdgeIterator edge = callEdges.begin(), - end = callEdges.end(); edge != end; edge++ ) { - BLInstrumentationNode* node = - (BLInstrumentationNode*)(*edge)->getSource(); - BasicBlock::iterator insertPoint = node->getBlock()->getFirstInsertionPt(); - - // Find the first function call - while( ((Instruction&)(*insertPoint)).getOpcode() != Instruction::Call ) - insertPoint++; - - DEBUG(dbgs() << "\nInstrumenting method call block '" - << node->getBlock()->getName() << "'\n"); - DEBUG(dbgs() << " Path number initialized: " - << ((node->getStartingPathNumber()) ? "yes" : "no") << "\n"); - - Value* newpn; - if( node->getStartingPathNumber() ) { - long inc = ((BLInstrumentationEdge*)(*edge))->getIncrement(); - if ( inc ) - newpn = BinaryOperator::Create(Instruction::Add, - node->getStartingPathNumber(), - createIncrementConstant(inc,32), - "pathNumber", insertPoint); - else - newpn = node->getStartingPathNumber(); - } else { - newpn = (Value*)createIncrementConstant( - ((BLInstrumentationEdge*)(*edge))->getIncrement(), 32); - } - - insertCounterIncrement(newpn, insertPoint, &dag); - insertCounterIncrement(newpn, node->getBlock()->getTerminator(), - &dag, false); - } -} - -// Entry point of the module -void PathProfiler::runOnFunction(std::vector<Constant*> &ftInit, - Function &F, Module &M) { - // Build DAG from CFG - BLInstrumentationDag dag = BLInstrumentationDag(F); - dag.init(); - - // give each path a unique integer value - dag.calculatePathNumbers(); - - // modify path increments to increase the efficiency - // of instrumentation - dag.calculateSpanningTree(); - dag.calculateChordIncrements(); - dag.pushInitialization(); - dag.pushCounters(); - dag.unlinkPhony(); - - // potentially generate .dot graph for the dag - if (DotPathDag) - dag.generateDotGraph (); - - // Should we store the information in an array or hash - if( dag.getNumberOfPaths() <= HASH_THRESHHOLD ) { - Type* t = ArrayType::get(Type::getInt32Ty(*Context), - dag.getNumberOfPaths()); - - dag.setCounterArray(new GlobalVariable(M, t, false, - GlobalValue::InternalLinkage, - Constant::getNullValue(t), "")); - } - - insertInstrumentation(dag, M); - - // Add to global function reference table - unsigned type; - Type* voidPtr = TypeBuilder<types::i<8>*, true>::get(*Context); - - if( dag.getNumberOfPaths() <= HASH_THRESHHOLD ) - type = ProfilingArray; - else - type = ProfilingHash; - - std::vector<Constant*> entryArray(3); - entryArray[0] = createIncrementConstant(type,32); - entryArray[1] = createIncrementConstant(dag.getNumberOfPaths(),32); - entryArray[2] = dag.getCounterArray() ? - ConstantExpr::getBitCast(dag.getCounterArray(), voidPtr) : - Constant::getNullValue(voidPtr); - - StructType* at = ftEntryTypeBuilder::get(*Context); - ConstantStruct* functionEntry = - (ConstantStruct*)ConstantStruct::get(at, entryArray); - ftInit.push_back(functionEntry); -} - -// Output the bitcode if we want to observe instrumentation changess -#define PRINT_MODULE dbgs() << \ - "\n\n============= MODULE BEGIN ===============\n" << M << \ - "\n============== MODULE END ================\n" - -bool PathProfiler::runOnModule(Module &M) { - Context = &M.getContext(); - - DEBUG(dbgs() - << "****************************************\n" - << "****************************************\n" - << "** **\n" - << "** PATH PROFILING INSTRUMENTATION **\n" - << "** **\n" - << "****************************************\n" - << "****************************************\n"); - - // No main, no instrumentation! - Function *Main = M.getFunction("main"); - - // Using fortran? ... this kind of works - if (!Main) - Main = M.getFunction("MAIN__"); - - if (!Main) { - errs() << "WARNING: cannot insert path profiling into a module" - << " with no main function!\n"; - return false; - } - - llvmIncrementHashFunction = M.getOrInsertFunction( - "llvm_increment_path_count", - Type::getVoidTy(*Context), // return type - Type::getInt32Ty(*Context), // function number - Type::getInt32Ty(*Context), // path number - NULL ); - - llvmDecrementHashFunction = M.getOrInsertFunction( - "llvm_decrement_path_count", - Type::getVoidTy(*Context), // return type - Type::getInt32Ty(*Context), // function number - Type::getInt32Ty(*Context), // path number - NULL ); - - std::vector<Constant*> ftInit; - unsigned functionNumber = 0; - for (Module::iterator F = M.begin(), E = M.end(); F != E; F++) { - if (F->isDeclaration()) - continue; - - DEBUG(dbgs() << "Function: " << F->getName() << "\n"); - functionNumber++; - - // set function number - currentFunctionNumber = functionNumber; - runOnFunction(ftInit, *F, M); - } - - Type *t = ftEntryTypeBuilder::get(*Context); - ArrayType* ftArrayType = ArrayType::get(t, ftInit.size()); - Constant* ftInitConstant = ConstantArray::get(ftArrayType, ftInit); - - DEBUG(dbgs() << " ftArrayType:" << *ftArrayType << "\n"); - - GlobalVariable* functionTable = - new GlobalVariable(M, ftArrayType, false, GlobalValue::InternalLinkage, - ftInitConstant, "functionPathTable"); - Type *eltType = ftArrayType->getTypeAtIndex((unsigned)0); - InsertProfilingInitCall(Main, "llvm_start_path_profiling", functionTable, - PointerType::getUnqual(eltType)); - - DEBUG(PRINT_MODULE); - - return true; -} - -// If this edge is a critical edge, then inserts a node at this edge. -// This edge becomes the first edge, and a new BallLarusEdge is created. -// Returns true if the edge was split -bool PathProfiler::splitCritical(BLInstrumentationEdge* edge, - BLInstrumentationDag* dag) { - unsigned succNum = edge->getSuccessorNumber(); - BallLarusNode* sourceNode = edge->getSource(); - BallLarusNode* targetNode = edge->getTarget(); - BasicBlock* sourceBlock = sourceNode->getBlock(); - BasicBlock* targetBlock = targetNode->getBlock(); - - if(sourceBlock == NULL || targetBlock == NULL - || sourceNode->getNumberSuccEdges() <= 1 - || targetNode->getNumberPredEdges() == 1 ) { - return(false); - } - - TerminatorInst* terminator = sourceBlock->getTerminator(); - - if( SplitCriticalEdge(terminator, succNum, this, false)) { - BasicBlock* newBlock = terminator->getSuccessor(succNum); - dag->splitUpdate(edge, newBlock); - return(true); - } else - return(false); -} |