From 93d545e691ef8c7c802a0c83dfb046e81d38e5d8 Mon Sep 17 00:00:00 2001 From: Anand Shukla Date: Sun, 3 Nov 2002 01:45:20 +0000 Subject: code to lightly instrument at branches git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4511 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Instrumentation/ProfilePaths/InstLoops.cpp | 210 +++++++++++++++++++++ 1 file changed, 210 insertions(+) create mode 100644 lib/Transforms/Instrumentation/ProfilePaths/InstLoops.cpp diff --git a/lib/Transforms/Instrumentation/ProfilePaths/InstLoops.cpp b/lib/Transforms/Instrumentation/ProfilePaths/InstLoops.cpp new file mode 100644 index 0000000000..21f3b25c0e --- /dev/null +++ b/lib/Transforms/Instrumentation/ProfilePaths/InstLoops.cpp @@ -0,0 +1,210 @@ +//===-- InstLoops.cpp ---------------------------------------- ---*- C++ -*--=// +// Pass to instrument loops +// +// At every backedge, insert a counter for that backedge and a call function +//===----------------------------------------------------------------------===// + +#include "llvm/Reoptimizer/InstLoops.h" +#include "llvm/Support/CFG.h" +#include "llvm/Constants.h" +#include "llvm/iMemory.h" +#include "llvm/GlobalVariable.h" +#include "llvm/DerivedTypes.h" +#include "llvm/iOther.h" +#include "llvm/iOperators.h" +#include "llvm/iTerminators.h" +#include "llvm/iPHINode.h" +#include "llvm/Module.h" +#include "llvm/Function.h" +#include "llvm/Pass.h" + +//this is used to color vertices +//during DFS + +enum Color{ + WHITE, + GREY, + BLACK +}; + +struct InstLoops : public FunctionPass { + bool runOnFunction(Function &F); +}; + +static RegisterOpt X("instloops", "Instrument backedges for profiling"); + +// createProfilePathsPass - Create a new pass to add path profiling +// +Pass *createInstLoopsPass() { + return new InstLoops(); +} + + +//helper function to get back edges: it is called by +//the "getBackEdges" function below +void getBackEdgesVisit(BasicBlock *u, + std::map &color, + std::map &d, + int &time, Value *threshold) { + + color[u]=GREY; + time++; + d[u]=time; + + for(BasicBlock::succ_iterator vl = succ_begin(u), + ve = succ_end(u); vl != ve; ++vl){ + + BasicBlock *BB = *vl; + + if(color[BB]!=GREY && color[BB]!=BLACK){ + getBackEdgesVisit(BB, color, d, time, threshold); + } + + //now checking for d and f vals + if(color[BB]==GREY){ + //so v is ancestor of u if time of u > time of v + if(d[u] >= d[BB]){ + //insert a new basic block: modify terminator accordingly! + BasicBlock *newBB = new BasicBlock("", u->getParent()); + BranchInst *ti = cast(u->getTerminator()); + unsigned char index = 1; + if(ti->getSuccessor(0) == BB){ + index = 0; + } + assert(ti->getNumSuccessors() > index && "Not enough successors!"); + ti->setSuccessor(index, newBB); + + //insert global variable of type int + Constant *initializer = Constant::getNullValue(Type::IntTy); + GlobalVariable *countVar = new GlobalVariable(Type::IntTy, false, true, + initializer, + "loopCounter", + u->getParent()->getParent()); + + //load the variable + Instruction *ldInst = new LoadInst(countVar,""); + + //increment + Instruction *addIn = + BinaryOperator::create(Instruction::Add, ldInst, + ConstantSInt::get(Type::IntTy,1), ""); + + //store + Instruction *stInst = new StoreInst(addIn, countVar); + + + Instruction *etr = new LoadInst(threshold, "threshold"); + Instruction *cmpInst = new SetCondInst(Instruction::SetLE, etr, + addIn, ""); + + BasicBlock *callTrigger = new BasicBlock("", u->getParent()); + //branch to calltrigger, or *vl + Instruction *newBr = new BranchInst(callTrigger, BB, cmpInst); + + BasicBlock::InstListType < = newBB->getInstList(); + + lt.push_back(ldInst); + lt.push_back(addIn); + lt.push_back(stInst); + lt.push_back(etr); + lt.push_back(cmpInst); + lt.push_back(newBr); + + //Now add instructions to the triggerCall BB + //now create a call function + //call llvm_first_trigger(int *x); + std::vector inCountArgs; + inCountArgs.push_back(PointerType::get(Type::IntTy)); + + const FunctionType *cFty = FunctionType::get(Type::VoidTy, inCountArgs, + false); + Function *inCountMth = + u->getParent()->getParent()->getOrInsertFunction("llvm_first_trigger", cFty); + + assert(inCountMth && "Initialize method could not be inserted!"); + + std::vector iniArgs; + iniArgs.push_back(countVar); + Instruction *call = new CallInst(inCountMth, iniArgs, ""); + callTrigger->getInstList().push_back(call); + callTrigger->getInstList().push_back(new BranchInst(BB)); + + //now iterate over *vl, and set its Phi nodes right + for(BasicBlock::iterator BB2Inst = BB->begin(), BBend = BB->end(); + BB2Inst != BBend; ++BB2Inst){ + + if(PHINode *phiInst=dyn_cast(&*BB2Inst)){ + int bbIndex = phiInst->getBasicBlockIndex(u); + if(bbIndex>=0){ + phiInst->setIncomingBlock(bbIndex, newBB); + + Value *val = phiInst->getIncomingValue((unsigned int)bbIndex); + phiInst->addIncoming(val, callTrigger); + } + } + } + } + } + } + color[u]=BLACK;//done with visiting the node and its neighbors +} + + +//getting the backedges in a graph +//Its a variation of DFS to get the backedges in the graph +//We get back edges by associating a time +//and a color with each vertex. +//The time of a vertex is the time when it was first visited +//The color of a vertex is initially WHITE, +//Changes to GREY when it is first visited, +//and changes to BLACK when ALL its neighbors +//have been visited +//So we have a back edge when we meet a successor of +//a node with smaller time, and GREY color +void getBackEdges(Function &F, Value *threshold){ + std::map color; + std::map d; + int time=0; + getBackEdgesVisit(F.begin(), color, d, time, threshold); +} + +//Per function pass for inserting counters and call function +bool InstLoops::runOnFunction(Function &F){ + + 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; + } + + if(F.getName() == "main"){ + //intialize threshold + std::vector initialize_args; + initialize_args.push_back(PointerType::get(Type::IntTy)); + + const FunctionType *Fty = FunctionType::get(Type::VoidTy, initialize_args, + false); + Function *initialMeth = F.getParent()->getOrInsertFunction("reoptimizerInitialize", Fty); + assert(initialMeth && "Initialize method could not be inserted!"); + + std::vector trargs; + trargs.push_back(threshold); + + new CallInst(initialMeth, trargs, "", F.begin()->begin()); + } + + assert(threshold && "GlobalVariable threshold not defined!"); + + if(F.isExternal()) { + return false; + } + + getBackEdges(F, threshold); + + return true; +} -- cgit v1.2.3