llvm-6502/lib/Transforms/Instrumentation/ProfilePaths/InstLoops.cpp
Chris Lattner 4b208dc599 Fix typeo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5278 91177308-0d34-0410-b5e6-96231b3b80d8
2003-01-14 22:34:36 +00:00

211 lines
6.8 KiB
C++

//===-- 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<InstLoops> X("instloops", "Instrument backedges for profiling");
// createInstLoopsPass - 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<BasicBlock *, Color > &color,
std::map<BasicBlock *, int > &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<BranchInst>(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 &lt = 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<const Type*> 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<Value *> 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<PHINode>(&*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<BasicBlock *, Color > color;
std::map<BasicBlock *, int> 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<const Type*> 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<Value *> 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;
}