It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Instrumentation/RSProfiling.cpp b/lib/Transforms/Instrumentation/RSProfiling.cpp
new file mode 100644
index 0000000..3c7efb1
--- /dev/null
+++ b/lib/Transforms/Instrumentation/RSProfiling.cpp
@@ -0,0 +1,650 @@
+//===- RSProfiling.cpp - Various profiling using random sampling ----------===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+//
+// These passes implement a random sampling based profiling. Different methods
+// of choosing when to sample are supported, as well as different types of
+// profiling. This is done as two passes. The first is a sequence of profiling
+// passes which insert profiling into the program, and remember what they
+// inserted.
+//
+// The second stage duplicates all instructions in a function, ignoring the
+// profiling code, then connects the two versions togeather at the entry and at
+// backedges. At each connection point a choice is made as to whether to jump
+// to the profiled code (take a sample) or execute the unprofiled code.
+//
+// It is highly recommeneded that after this pass one runs mem2reg and adce
+// (instcombine load-vn gdce dse also are good to run afterwards)
+//
+// This design is intended to make the profiling passes independent of the RS
+// framework, but any profiling pass that implements the RSProfiling interface
+// is compatible with the rs framework (and thus can be sampled)
+//
+// TODO: obviously the block and function profiling are almost identical to the
+// existing ones, so they can be unified (esp since these passes are valid
+// without the rs framework).
+// TODO: Fix choice code so that frequency is not hard coded
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Pass.h"
+#include "llvm/Module.h"
+#include "llvm/Instructions.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Transforms/Instrumentation.h"
+#include "RSProfiling.h"
+#include <set>
+#include <map>
+#include <queue>
+#include <list>
+using namespace llvm;
+
+namespace {
+ enum RandomMeth {
+ GBV, GBVO, HOSTCC
+ };
+
+ cl::opt<RandomMeth> RandomMethod("profile-randomness",
+ cl::desc("How to randomly choose to profile:"),
+ cl::values(
+ clEnumValN(GBV, "global", "global counter"),
+ clEnumValN(GBVO, "ra_global",
+ "register allocated global counter"),
+ clEnumValN(HOSTCC, "rdcc", "cycle counter"),
+ clEnumValEnd));
+
+ /// NullProfilerRS - The basic profiler that does nothing. It is the default
+ /// profiler and thus terminates RSProfiler chains. It is useful for
+ /// measuring framework overhead
+ class VISIBILITY_HIDDEN NullProfilerRS : public RSProfilers {
+ public:
+ static char ID; // Pass identification, replacement for typeid
+ bool isProfiling(Value* v) {
+ return false;
+ }
+ bool runOnModule(Module &M) {
+ return false;
+ }
+ void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ }
+ };
+
+ static RegisterAnalysisGroup<RSProfilers> A("Profiling passes");
+ static RegisterPass<NullProfilerRS> NP("insert-null-profiling-rs",
+ "Measure profiling framework overhead");
+ static RegisterAnalysisGroup<RSProfilers, true> NPT(NP);
+
+ /// Chooser - Something that chooses when to make a sample of the profiled code
+ class VISIBILITY_HIDDEN Chooser {
+ public:
+ /// ProcessChoicePoint - is called for each basic block inserted to choose
+ /// between normal and sample code
+ virtual void ProcessChoicePoint(BasicBlock*) = 0;
+ /// PrepFunction - is called once per function before other work is done.
+ /// This gives the opertunity to insert new allocas and such.
+ virtual void PrepFunction(Function*) = 0;
+ virtual ~Chooser() {}
+ };
+
+ //Things that implement sampling policies
+ //A global value that is read-mod-stored to choose when to sample.
+ //A sample is taken when the global counter hits 0
+ class VISIBILITY_HIDDEN GlobalRandomCounter : public Chooser {
+ GlobalVariable* Counter;
+ Value* ResetValue;
+ const Type* T;
+ public:
+ GlobalRandomCounter(Module& M, const Type* t, uint64_t resetval);
+ virtual ~GlobalRandomCounter();
+ virtual void PrepFunction(Function* F);
+ virtual void ProcessChoicePoint(BasicBlock* bb);
+ };
+
+ //Same is GRC, but allow register allocation of the global counter
+ class VISIBILITY_HIDDEN GlobalRandomCounterOpt : public Chooser {
+ GlobalVariable* Counter;
+ Value* ResetValue;
+ AllocaInst* AI;
+ const Type* T;
+ public:
+ GlobalRandomCounterOpt(Module& M, const Type* t, uint64_t resetval);
+ virtual ~GlobalRandomCounterOpt();
+ virtual void PrepFunction(Function* F);
+ virtual void ProcessChoicePoint(BasicBlock* bb);
+ };
+
+ //Use the cycle counter intrinsic as a source of pseudo randomness when
+ //deciding when to sample.
+ class VISIBILITY_HIDDEN CycleCounter : public Chooser {
+ uint64_t rm;
+ Constant *F;
+ public:
+ CycleCounter(Module& m, uint64_t resetmask);
+ virtual ~CycleCounter();
+ virtual void PrepFunction(Function* F);
+ virtual void ProcessChoicePoint(BasicBlock* bb);
+ };
+
+ /// ProfilerRS - Insert the random sampling framework
+ struct VISIBILITY_HIDDEN ProfilerRS : public FunctionPass {
+ static char ID; // Pass identification, replacement for typeid
+ ProfilerRS() : FunctionPass((intptr_t)&ID) {}
+
+ std::map<Value*, Value*> TransCache;
+ std::set<BasicBlock*> ChoicePoints;
+ Chooser* c;
+
+ //Translate and duplicate values for the new profile free version of stuff
+ Value* Translate(Value* v);
+ //Duplicate an entire function (with out profiling)
+ void Duplicate(Function& F, RSProfilers& LI);
+ //Called once for each backedge, handle the insertion of choice points and
+ //the interconection of the two versions of the code
+ void ProcessBackEdge(BasicBlock* src, BasicBlock* dst, Function& F);
+ bool runOnFunction(Function& F);
+ bool doInitialization(Module &M);
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const;
+ };
+
+ RegisterPass<ProfilerRS> X("insert-rs-profiling-framework",
+ "Insert random sampling instrumentation framework");
+}
+
+char RSProfilers::ID = 0;
+char NullProfilerRS::ID = 0;
+char ProfilerRS::ID = 0;
+
+//Local utilities
+static void ReplacePhiPred(BasicBlock* btarget,
+ BasicBlock* bold, BasicBlock* bnew);
+
+static void CollapsePhi(BasicBlock* btarget, BasicBlock* bsrc);
+
+template<class T>
+static void recBackEdge(BasicBlock* bb, T& BackEdges,
+ std::map<BasicBlock*, int>& color,
+ std::map<BasicBlock*, int>& depth,
+ std::map<BasicBlock*, int>& finish,
+ int& time);
+
+//find the back edges and where they go to
+template<class T>
+static void getBackEdges(Function& F, T& BackEdges);
+
+
+///////////////////////////////////////
+// Methods of choosing when to profile
+///////////////////////////////////////
+
+GlobalRandomCounter::GlobalRandomCounter(Module& M, const Type* t,
+ uint64_t resetval) : T(t) {
+ ConstantInt* Init = ConstantInt::get(T, resetval);
+ ResetValue = Init;
+ Counter = new GlobalVariable(T, false, GlobalValue::InternalLinkage,
+ Init, "RandomSteeringCounter", &M);
+}
+
+GlobalRandomCounter::~GlobalRandomCounter() {}
+
+void GlobalRandomCounter::PrepFunction(Function* F) {}
+
+void GlobalRandomCounter::ProcessChoicePoint(BasicBlock* bb) {
+ BranchInst* t = cast<BranchInst>(bb->getTerminator());
+
+ //decrement counter
+ LoadInst* l = new LoadInst(Counter, "counter", t);
+
+ ICmpInst* s = new ICmpInst(ICmpInst::ICMP_EQ, l, ConstantInt::get(T, 0),
+ "countercc", t);
+
+ Value* nv = BinaryOperator::createSub(l, ConstantInt::get(T, 1),
+ "counternew", t);
+ new StoreInst(nv, Counter, t);
+ t->setCondition(s);
+
+ //reset counter
+ BasicBlock* oldnext = t->getSuccessor(0);
+ BasicBlock* resetblock = new BasicBlock("reset", oldnext->getParent(),
+ oldnext);
+ TerminatorInst* t2 = new BranchInst(oldnext, resetblock);
+ t->setSuccessor(0, resetblock);
+ new StoreInst(ResetValue, Counter, t2);
+ ReplacePhiPred(oldnext, bb, resetblock);
+}
+
+GlobalRandomCounterOpt::GlobalRandomCounterOpt(Module& M, const Type* t,
+ uint64_t resetval)
+ : AI(0), T(t) {
+ ConstantInt* Init = ConstantInt::get(T, resetval);
+ ResetValue = Init;
+ Counter = new GlobalVariable(T, false, GlobalValue::InternalLinkage,
+ Init, "RandomSteeringCounter", &M);
+}
+
+GlobalRandomCounterOpt::~GlobalRandomCounterOpt() {}
+
+void GlobalRandomCounterOpt::PrepFunction(Function* F) {
+ //make a local temporary to cache the global
+ BasicBlock& bb = F->getEntryBlock();
+ BasicBlock::iterator InsertPt = bb.begin();
+ AI = new AllocaInst(T, 0, "localcounter", InsertPt);
+ LoadInst* l = new LoadInst(Counter, "counterload", InsertPt);
+ new StoreInst(l, AI, InsertPt);
+
+ //modify all functions and return values to restore the local variable to/from
+ //the global variable
+ for(Function::iterator fib = F->begin(), fie = F->end();
+ fib != fie; ++fib)
+ for(BasicBlock::iterator bib = fib->begin(), bie = fib->end();
+ bib != bie; ++bib)
+ if (isa<CallInst>(bib)) {
+ LoadInst* l = new LoadInst(AI, "counter", bib);
+ new StoreInst(l, Counter, bib);
+ l = new LoadInst(Counter, "counter", ++bib);
+ new StoreInst(l, AI, bib--);
+ } else if (isa<InvokeInst>(bib)) {
+ LoadInst* l = new LoadInst(AI, "counter", bib);
+ new StoreInst(l, Counter, bib);
+
+ BasicBlock* bb = cast<InvokeInst>(bib)->getNormalDest();
+ BasicBlock::iterator i = bb->begin();
+ while (isa<PHINode>(i))
+ ++i;
+ l = new LoadInst(Counter, "counter", i);
+
+ bb = cast<InvokeInst>(bib)->getUnwindDest();
+ i = bb->begin();
+ while (isa<PHINode>(i)) ++i;
+ l = new LoadInst(Counter, "counter", i);
+ new StoreInst(l, AI, i);
+ } else if (isa<UnwindInst>(&*bib) || isa<ReturnInst>(&*bib)) {
+ LoadInst* l = new LoadInst(AI, "counter", bib);
+ new StoreInst(l, Counter, bib);
+ }
+}
+
+void GlobalRandomCounterOpt::ProcessChoicePoint(BasicBlock* bb) {
+ BranchInst* t = cast<BranchInst>(bb->getTerminator());
+
+ //decrement counter
+ LoadInst* l = new LoadInst(AI, "counter", t);
+
+ ICmpInst* s = new ICmpInst(ICmpInst::ICMP_EQ, l, ConstantInt::get(T, 0),
+ "countercc", t);
+
+ Value* nv = BinaryOperator::createSub(l, ConstantInt::get(T, 1),
+ "counternew", t);
+ new StoreInst(nv, AI, t);
+ t->setCondition(s);
+
+ //reset counter
+ BasicBlock* oldnext = t->getSuccessor(0);
+ BasicBlock* resetblock = new BasicBlock("reset", oldnext->getParent(),
+ oldnext);
+ TerminatorInst* t2 = new BranchInst(oldnext, resetblock);
+ t->setSuccessor(0, resetblock);
+ new StoreInst(ResetValue, AI, t2);
+ ReplacePhiPred(oldnext, bb, resetblock);
+}
+
+
+CycleCounter::CycleCounter(Module& m, uint64_t resetmask) : rm(resetmask) {
+ F = m.getOrInsertFunction("llvm.readcyclecounter", Type::Int64Ty, NULL);
+}
+
+CycleCounter::~CycleCounter() {}
+
+void CycleCounter::PrepFunction(Function* F) {}
+
+void CycleCounter::ProcessChoicePoint(BasicBlock* bb) {
+ BranchInst* t = cast<BranchInst>(bb->getTerminator());
+
+ CallInst* c = new CallInst(F, "rdcc", t);
+ BinaryOperator* b =
+ BinaryOperator::createAnd(c, ConstantInt::get(Type::Int64Ty, rm),
+ "mrdcc", t);
+
+ ICmpInst *s = new ICmpInst(ICmpInst::ICMP_EQ, b,
+ ConstantInt::get(Type::Int64Ty, 0),
+ "mrdccc", t);
+
+ t->setCondition(s);
+}
+
+///////////////////////////////////////
+// Profiling:
+///////////////////////////////////////
+bool RSProfilers_std::isProfiling(Value* v) {
+ if (profcode.find(v) != profcode.end())
+ return true;
+ //else
+ RSProfilers& LI = getAnalysis<RSProfilers>();
+ return LI.isProfiling(v);
+}
+
+void RSProfilers_std::IncrementCounterInBlock(BasicBlock *BB, unsigned CounterNum,
+ GlobalValue *CounterArray) {
+ // Insert the increment after any alloca or PHI instructions...
+ BasicBlock::iterator InsertPos = BB->begin();
+ while (isa<AllocaInst>(InsertPos) || isa<PHINode>(InsertPos))
+ ++InsertPos;
+
+ // Create the getelementptr constant expression
+ std::vector<Constant*> Indices(2);
+ Indices[0] = Constant::getNullValue(Type::Int32Ty);
+ Indices[1] = ConstantInt::get(Type::Int32Ty, CounterNum);
+ Constant *ElementPtr = ConstantExpr::getGetElementPtr(CounterArray,
+ &Indices[0], 2);
+
+ // Load, increment and store the value back.
+ Value *OldVal = new LoadInst(ElementPtr, "OldCounter", InsertPos);
+ profcode.insert(OldVal);
+ Value *NewVal = BinaryOperator::createAdd(OldVal,
+ ConstantInt::get(Type::Int32Ty, 1),
+ "NewCounter", InsertPos);
+ profcode.insert(NewVal);
+ profcode.insert(new StoreInst(NewVal, ElementPtr, InsertPos));
+}
+
+void RSProfilers_std::getAnalysisUsage(AnalysisUsage &AU) const {
+ //grab any outstanding profiler, or get the null one
+ AU.addRequired<RSProfilers>();
+}
+
+///////////////////////////////////////
+// RS Framework
+///////////////////////////////////////
+
+Value* ProfilerRS::Translate(Value* v) {
+ if(TransCache[v])
+ return TransCache[v];
+
+ if (BasicBlock* bb = dyn_cast<BasicBlock>(v)) {
+ if (bb == &bb->getParent()->getEntryBlock())
+ TransCache[bb] = bb; //don't translate entry block
+ else
+ TransCache[bb] = new BasicBlock("dup_" + bb->getName(), bb->getParent(),
+ NULL);
+ return TransCache[bb];
+ } else if (Instruction* i = dyn_cast<Instruction>(v)) {
+ //we have already translated this
+ //do not translate entry block allocas
+ if(&i->getParent()->getParent()->getEntryBlock() == i->getParent()) {
+ TransCache[i] = i;
+ return i;
+ } else {
+ //translate this
+ Instruction* i2 = i->clone();
+ if (i->hasName())
+ i2->setName("dup_" + i->getName());
+ TransCache[i] = i2;
+ //NumNewInst++;
+ for (unsigned x = 0; x < i2->getNumOperands(); ++x)
+ i2->setOperand(x, Translate(i2->getOperand(x)));
+ return i2;
+ }
+ } else if (isa<Function>(v) || isa<Constant>(v) || isa<Argument>(v)) {
+ TransCache[v] = v;
+ return v;
+ }
+ assert(0 && "Value not handled");
+ return 0;
+}
+
+void ProfilerRS::Duplicate(Function& F, RSProfilers& LI)
+{
+ //perform a breadth first search, building up a duplicate of the code
+ std::queue<BasicBlock*> worklist;
+ std::set<BasicBlock*> seen;
+
+ //This loop ensures proper BB order, to help performance
+ for (Function::iterator fib = F.begin(), fie = F.end(); fib != fie; ++fib)
+ worklist.push(fib);
+ while (!worklist.empty()) {
+ Translate(worklist.front());
+ worklist.pop();
+ }
+
+ //remember than reg2mem created a new entry block we don't want to duplicate
+ worklist.push(F.getEntryBlock().getTerminator()->getSuccessor(0));
+ seen.insert(&F.getEntryBlock());
+
+ while (!worklist.empty()) {
+ BasicBlock* bb = worklist.front();
+ worklist.pop();
+ if(seen.find(bb) == seen.end()) {
+ BasicBlock* bbtarget = cast<BasicBlock>(Translate(bb));
+ BasicBlock::InstListType& instlist = bbtarget->getInstList();
+ for (BasicBlock::iterator iib = bb->begin(), iie = bb->end();
+ iib != iie; ++iib) {
+ //NumOldInst++;
+ if (!LI.isProfiling(&*iib)) {
+ Instruction* i = cast<Instruction>(Translate(iib));
+ instlist.insert(bbtarget->end(), i);
+ }
+ }
+ //updated search state;
+ seen.insert(bb);
+ TerminatorInst* ti = bb->getTerminator();
+ for (unsigned x = 0; x < ti->getNumSuccessors(); ++x) {
+ BasicBlock* bbs = ti->getSuccessor(x);
+ if (seen.find(bbs) == seen.end()) {
+ worklist.push(bbs);
+ }
+ }
+ }
+ }
+}
+
+void ProfilerRS::ProcessBackEdge(BasicBlock* src, BasicBlock* dst, Function& F) {
+ //given a backedge from B -> A, and translations A' and B',
+ //a: insert C and C'
+ //b: add branches in C to A and A' and in C' to A and A'
+ //c: mod terminators@B, replace A with C
+ //d: mod terminators@B', replace A' with C'
+ //e: mod phis@A for pred B to be pred C
+ // if multiple entries, simplify to one
+ //f: mod phis@A' for pred B' to be pred C'
+ // if multiple entries, simplify to one
+ //g: for all phis@A with pred C using x
+ // add in edge from C' using x'
+ // add in edge from C using x in A'
+
+ //a:
+ Function::iterator BBN = src; ++BBN;
+ BasicBlock* bbC = new BasicBlock("choice", &F, BBN);
+ //ChoicePoints.insert(bbC);
+ BBN = cast<BasicBlock>(Translate(src));
+ BasicBlock* bbCp = new BasicBlock("choice", &F, ++BBN);
+ ChoicePoints.insert(bbCp);
+
+ //b:
+ new BranchInst(cast<BasicBlock>(Translate(dst)), bbC);
+ new BranchInst(dst, cast<BasicBlock>(Translate(dst)),
+ ConstantInt::get(Type::Int1Ty, true), bbCp);
+ //c:
+ {
+ TerminatorInst* iB = src->getTerminator();
+ for (unsigned x = 0; x < iB->getNumSuccessors(); ++x)
+ if (iB->getSuccessor(x) == dst)
+ iB->setSuccessor(x, bbC);
+ }
+ //d:
+ {
+ TerminatorInst* iBp = cast<TerminatorInst>(Translate(src->getTerminator()));
+ for (unsigned x = 0; x < iBp->getNumSuccessors(); ++x)
+ if (iBp->getSuccessor(x) == cast<BasicBlock>(Translate(dst)))
+ iBp->setSuccessor(x, bbCp);
+ }
+ //e:
+ ReplacePhiPred(dst, src, bbC);
+ //src could be a switch, in which case we are replacing several edges with one
+ //thus collapse those edges int the Phi
+ CollapsePhi(dst, bbC);
+ //f:
+ ReplacePhiPred(cast<BasicBlock>(Translate(dst)),
+ cast<BasicBlock>(Translate(src)),bbCp);
+ CollapsePhi(cast<BasicBlock>(Translate(dst)), bbCp);
+ //g:
+ for(BasicBlock::iterator ib = dst->begin(), ie = dst->end(); ib != ie;
+ ++ib)
+ if (PHINode* phi = dyn_cast<PHINode>(&*ib)) {
+ for(unsigned x = 0; x < phi->getNumIncomingValues(); ++x)
+ if(bbC == phi->getIncomingBlock(x)) {
+ phi->addIncoming(Translate(phi->getIncomingValue(x)), bbCp);
+ cast<PHINode>(Translate(phi))->addIncoming(phi->getIncomingValue(x),
+ bbC);
+ }
+ phi->removeIncomingValue(bbC);
+ }
+}
+
+bool ProfilerRS::runOnFunction(Function& F) {
+ if (!F.isDeclaration()) {
+ std::set<std::pair<BasicBlock*, BasicBlock*> > BackEdges;
+ RSProfilers& LI = getAnalysis<RSProfilers>();
+
+ getBackEdges(F, BackEdges);
+ Duplicate(F, LI);
+ //assume that stuff worked. now connect the duplicated basic blocks
+ //with the originals in such a way as to preserve ssa. yuk!
+ for (std::set<std::pair<BasicBlock*, BasicBlock*> >::iterator
+ ib = BackEdges.begin(), ie = BackEdges.end(); ib != ie; ++ib)
+ ProcessBackEdge(ib->first, ib->second, F);
+
+ //oh, and add the edge from the reg2mem created entry node to the
+ //duplicated second node
+ TerminatorInst* T = F.getEntryBlock().getTerminator();
+ ReplaceInstWithInst(T, new BranchInst(T->getSuccessor(0),
+ cast<BasicBlock>(
+ Translate(T->getSuccessor(0))),
+ ConstantInt::get(Type::Int1Ty, true)));
+
+ //do whatever is needed now that the function is duplicated
+ c->PrepFunction(&F);
+
+ //add entry node to choice points
+ ChoicePoints.insert(&F.getEntryBlock());
+
+ for (std::set<BasicBlock*>::iterator
+ ii = ChoicePoints.begin(), ie = ChoicePoints.end(); ii != ie; ++ii)
+ c->ProcessChoicePoint(*ii);
+
+ ChoicePoints.clear();
+ TransCache.clear();
+
+ return true;
+ }
+ return false;
+}
+
+bool ProfilerRS::doInitialization(Module &M) {
+ switch (RandomMethod) {
+ case GBV:
+ c = new GlobalRandomCounter(M, Type::Int32Ty, (1 << 14) - 1);
+ break;
+ case GBVO:
+ c = new GlobalRandomCounterOpt(M, Type::Int32Ty, (1 << 14) - 1);
+ break;
+ case HOSTCC:
+ c = new CycleCounter(M, (1 << 14) - 1);
+ break;
+ };
+ return true;
+}
+
+void ProfilerRS::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<RSProfilers>();
+ AU.addRequiredID(DemoteRegisterToMemoryID);
+}
+
+///////////////////////////////////////
+// Utilities:
+///////////////////////////////////////
+static void ReplacePhiPred(BasicBlock* btarget,
+ BasicBlock* bold, BasicBlock* bnew) {
+ for(BasicBlock::iterator ib = btarget->begin(), ie = btarget->end();
+ ib != ie; ++ib)
+ if (PHINode* phi = dyn_cast<PHINode>(&*ib)) {
+ for(unsigned x = 0; x < phi->getNumIncomingValues(); ++x)
+ if(bold == phi->getIncomingBlock(x))
+ phi->setIncomingBlock(x, bnew);
+ }
+}
+
+static void CollapsePhi(BasicBlock* btarget, BasicBlock* bsrc) {
+ for(BasicBlock::iterator ib = btarget->begin(), ie = btarget->end();
+ ib != ie; ++ib)
+ if (PHINode* phi = dyn_cast<PHINode>(&*ib)) {
+ std::map<BasicBlock*, Value*> counter;
+ for(unsigned i = 0; i < phi->getNumIncomingValues(); ) {
+ if (counter[phi->getIncomingBlock(i)]) {
+ assert(phi->getIncomingValue(i) == counter[phi->getIncomingBlock(i)]);
+ phi->removeIncomingValue(i, false);
+ } else {
+ counter[phi->getIncomingBlock(i)] = phi->getIncomingValue(i);
+ ++i;
+ }
+ }
+ }
+}
+
+template<class T>
+static void recBackEdge(BasicBlock* bb, T& BackEdges,
+ std::map<BasicBlock*, int>& color,
+ std::map<BasicBlock*, int>& depth,
+ std::map<BasicBlock*, int>& finish,
+ int& time)
+{
+ color[bb] = 1;
+ ++time;
+ depth[bb] = time;
+ TerminatorInst* t= bb->getTerminator();
+ for(unsigned i = 0; i < t->getNumSuccessors(); ++i) {
+ BasicBlock* bbnew = t->getSuccessor(i);
+ if (color[bbnew] == 0)
+ recBackEdge(bbnew, BackEdges, color, depth, finish, time);
+ else if (color[bbnew] == 1) {
+ BackEdges.insert(std::make_pair(bb, bbnew));
+ //NumBackEdges++;
+ }
+ }
+ color[bb] = 2;
+ ++time;
+ finish[bb] = time;
+}
+
+
+
+//find the back edges and where they go to
+template<class T>
+static void getBackEdges(Function& F, T& BackEdges) {
+ std::map<BasicBlock*, int> color;
+ std::map<BasicBlock*, int> depth;
+ std::map<BasicBlock*, int> finish;
+ int time = 0;
+ recBackEdge(&F.getEntryBlock(), BackEdges, color, depth, finish, time);
+ DOUT << F.getName() << " " << BackEdges.size() << "\n";
+}
+
+
+//Creation functions
+ModulePass* llvm::createNullProfilerRSPass() {
+ return new NullProfilerRS();
+}
+
+FunctionPass* llvm::createRSProfilingPass() {
+ return new ProfilerRS();
+}