// of a function is identified through a unique number. the code insertion
// is optimal in the sense that its inserted over a minimal set of edges. Also,
// the algorithm makes sure than initialization, path increment and counter
-// update can be collapsed into minmimum number of edges.
+// update can be collapsed into minimum number of edges.
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Instrumentation/ProfilePaths.h"
#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
+#include "llvm/Transforms/Instrumentation/Graph.h"
#include "llvm/Support/CFG.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/iMemory.h"
-#include "Graph.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Module.h"
+#include <iostream>
+#include <fstream>
using std::vector;
struct ProfilePaths : public FunctionPass {
- const char *getPassName() const { return "ProfilePaths"; }
-
bool runOnFunction(Function &F);
// Before this pass, make sure that there is only one
// entry and only one exit node for the function in the CFG of the function
//
void ProfilePaths::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired(UnifyFunctionExitNodes::ID);
+ AU.addRequired<UnifyFunctionExitNodes>();
}
};
+static RegisterOpt<ProfilePaths> X("paths", "Profile Paths");
+
// createProfilePathsPass - Create a new pass to add path profiling
//
Pass *createProfilePathsPass() {
}
-static Node *findBB(std::set<Node *> &st, BasicBlock *BB){
- for(std::set<Node *>::iterator si=st.begin(); si!=st.end(); ++si){
+static Node *findBB(std::vector<Node *> &st, BasicBlock *BB){
+ for(std::vector<Node *>::iterator si=st.begin(); si!=st.end(); ++si){
if(((*si)->getElement())==BB){
return *si;
}
//Per function pass for inserting counters and trigger code
bool ProfilePaths::runOnFunction(Function &F){
+
+ static int mn = -1;
+
+ if(F.isExternal()) {
+ return false;
+ }
+
+ //increment counter for instrumented functions. mn is now function#
+ mn++;
+
// Transform the cfg s.t. we have just one exit node
BasicBlock *ExitNode = getAnalysis<UnifyFunctionExitNodes>().getExitNode();
-
- // iterating over BBs and making graph
- std::set<Node *> nodes;
- std::set<Edge> edges;
+
+ //iterating over BBs and making graph
+ std::vector<Node *> nodes;
+ std::vector<Edge> edges;
+
Node *tmp;
- Node *exitNode, *startNode;
+ Node *exitNode = 0, *startNode = 0;
// The nodes must be uniquesly identified:
// That is, no two nodes must hav same BB*
- // First enter just nodes: later enter edges
for (Function::iterator BB = F.begin(), BE = F.end(); BB != BE; ++BB) {
Node *nd=new Node(BB);
- nodes.insert(nd);
+ nodes.push_back(nd);
if(&*BB == ExitNode)
exitNode=nd;
if(&*BB==F.begin())
for (Function::iterator BB = F.begin(), BE = F.end(); BB != BE; ++BB){
Node *nd=findBB(nodes, BB);
assert(nd && "No node for this edge!");
+
for(BasicBlock::succ_iterator s=succ_begin(BB), se=succ_end(BB);
s!=se; ++s){
Node *nd2=findBB(nodes,*s);
assert(nd2 && "No node for this edge!");
Edge ed(nd,nd2,0);
- edges.insert(ed);
+ edges.push_back(ed);
}
}
Graph g(nodes,edges, startNode, exitNode);
- DEBUG(printGraph(g));
+#ifdef DEBUG_PATH_PROFILES
+ std::cerr<<"Original graph\n";
+ printGraph(g);
+#endif
- BasicBlock *fr=&F.front();
+ BasicBlock *fr = &F.front();
- // If only one BB, don't instrument
- if (++F.begin() == F.end()) {
- // The graph is made acyclic: this is done
- // by removing back edges for now, and adding them later on
- vector<Edge> be;
- g.getBackEdges(be);
- DEBUG(cerr << "Backedges:" << be.size() << "\n");
-
- // Now we need to reflect the effect of back edges
- // This is done by adding dummy edges
- // If a->b is a back edge
- // Then we add 2 back edges for it:
- // 1. from root->b (in vector stDummy)
- // and 2. from a->exit (in vector exDummy)
- vector<Edge> stDummy;
- vector<Edge> exDummy;
- addDummyEdges(stDummy, exDummy, g, be);
-
- // Now, every edge in the graph is assigned a weight
- // This weight later adds on to assign path
- // numbers to different paths in the graph
- // All paths for now are acyclic,
- // since no back edges in the graph now
- // numPaths is the number of acyclic paths in the graph
- int numPaths=valueAssignmentToEdges(g);
-
- // create instruction allocation r and count
- // r is the variable that'll act like an accumulator
- // all along the path, we just add edge values to r
- // and at the end, r reflects the path number
- // count is an array: count[x] would store
- // the number of executions of path numbered x
- Instruction *rVar=new
- AllocaInst(PointerType::get(Type::IntTy),
- ConstantUInt::get(Type::UIntTy,1),"R");
-
- Instruction *countVar=new
- AllocaInst(PointerType::get(Type::IntTy),
- ConstantUInt::get(Type::UIntTy, numPaths), "Count");
-
- // insert initialization code in first (entry) BB
- // this includes initializing r and count
- insertInTopBB(&F.getEntryNode(),numPaths, rVar, countVar);
-
- // now process the graph: get path numbers,
- // get increments along different paths,
- // and assign "increments" and "updates" (to r and count)
- // "optimally". Finally, insert llvm code along various edges
- processGraph(g, rVar, countVar, be, stDummy, exDummy);
+ // The graph is made acyclic: this is done
+ // by removing back edges for now, and adding them later on
+ vector<Edge> be;
+ std::map<Node *, int> nodePriority; //it ranks nodes in depth first order traversal
+ g.getBackEdges(be, nodePriority);
+
+#ifdef DEBUG_PATH_PROFILES
+ std::cerr<<"BackEdges-------------\n";
+ for(vector<Edge>::iterator VI=be.begin(); VI!=be.end(); ++VI){
+ printEdge(*VI);
+ cerr<<"\n";
}
+ std::cerr<<"------\n";
+#endif
+
+#ifdef DEBUG_PATH_PROFILES
+ cerr<<"Backedges:"<<be.size()<<endl;
+#endif
+ //Now we need to reflect the effect of back edges
+ //This is done by adding dummy edges
+ //If a->b is a back edge
+ //Then we add 2 back edges for it:
+ //1. from root->b (in vector stDummy)
+ //and 2. from a->exit (in vector exDummy)
+ vector<Edge> stDummy;
+ vector<Edge> exDummy;
+ addDummyEdges(stDummy, exDummy, g, be);
+
+#ifdef DEBUG_PATH_PROFILES
+ std::cerr<<"After adding dummy edges\n";
+ printGraph(g);
+#endif
+
+ // Now, every edge in the graph is assigned a weight
+ // This weight later adds on to assign path
+ // numbers to different paths in the graph
+ // All paths for now are acyclic,
+ // since no back edges in the graph now
+ // numPaths is the number of acyclic paths in the graph
+ int numPaths=valueAssignmentToEdges(g, nodePriority, be);
+
+ if(numPaths<=1 || numPaths >5000) return false;
+
+#ifdef DEBUG_PATH_PROFILES
+ printGraph(g);
+#endif
+
+ //create instruction allocation r and count
+ //r is the variable that'll act like an accumulator
+ //all along the path, we just add edge values to r
+ //and at the end, r reflects the path number
+ //count is an array: count[x] would store
+ //the number of executions of path numbered x
+
+ Instruction *rVar=new
+ AllocaInst(Type::IntTy,
+ ConstantUInt::get(Type::UIntTy,1),"R");
+ Instruction *countVar=new
+ AllocaInst(Type::IntTy,
+ ConstantUInt::get(Type::UIntTy, numPaths), "Count");
+
+ static GlobalVariable *threshold = NULL;
+ static bool insertedThreshold = false;
+
+ if(!insertedThreshold){
+ threshold = new GlobalVariable(Type::IntTy, false, false, 0,
+ "reopt_threshold");
+
+ F.getParent()->getGlobalList().push_back(threshold);
+ insertedThreshold = true;
+ }
+
+ assert(threshold && "GlobalVariable threshold not defined!");
+
+ // insert initialization code in first (entry) BB
+ // this includes initializing r and count
+ insertInTopBB(&F.getEntryNode(),numPaths, rVar, countVar, threshold);
+
+ //now process the graph: get path numbers,
+ //get increments along different paths,
+ //and assign "increments" and "updates" (to r and count)
+ //"optimally". Finally, insert llvm code along various edges
+ processGraph(g, rVar, countVar, be, stDummy, exDummy, numPaths, mn,
+ threshold);
+
return true; // Always modifies function
}