1 //===- GCOVProfiling.cpp - Insert edge counters for gcov profiling --------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This pass implements GCOV-style profiling. When this pass is run it emits
11 // "gcno" files next to the existing source, and instruments the code that runs
12 // to records the edges between blocks that run and emit a complementary "gcda"
15 //===----------------------------------------------------------------------===//
17 #define DEBUG_TYPE "insert-gcov-profiling"
19 #include "ProfilingUtils.h"
20 #include "llvm/Transforms/Instrumentation.h"
21 #include "llvm/DebugInfo.h"
22 #include "llvm/IRBuilder.h"
23 #include "llvm/Instructions.h"
24 #include "llvm/Module.h"
25 #include "llvm/Pass.h"
26 #include "llvm/ADT/DenseMap.h"
27 #include "llvm/ADT/STLExtras.h"
28 #include "llvm/ADT/Statistic.h"
29 #include "llvm/ADT/StringExtras.h"
30 #include "llvm/ADT/StringMap.h"
31 #include "llvm/ADT/UniqueVector.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/DebugLoc.h"
34 #include "llvm/Support/InstIterator.h"
35 #include "llvm/Support/PathV2.h"
36 #include "llvm/Support/raw_ostream.h"
37 #include "llvm/Transforms/Utils/ModuleUtils.h"
43 class GCOVProfiler : public ModulePass {
47 : ModulePass(ID), EmitNotes(true), EmitData(true), Use402Format(false),
48 UseExtraChecksum(false) {
49 initializeGCOVProfilerPass(*PassRegistry::getPassRegistry());
51 GCOVProfiler(bool EmitNotes, bool EmitData, bool use402Format = false,
52 bool useExtraChecksum = false)
53 : ModulePass(ID), EmitNotes(EmitNotes), EmitData(EmitData),
54 Use402Format(use402Format), UseExtraChecksum(useExtraChecksum) {
55 assert((EmitNotes || EmitData) && "GCOVProfiler asked to do nothing?");
56 initializeGCOVProfilerPass(*PassRegistry::getPassRegistry());
58 virtual const char *getPassName() const {
59 return "GCOV Profiler";
62 bool runOnModule(Module &M);
64 // Create the GCNO files for the Module based on DebugInfo.
67 // Modify the program to track transitions along edges and call into the
68 // profiling runtime to emit .gcda files when run.
69 bool emitProfileArcs();
71 // Get pointers to the functions in the runtime library.
72 Constant *getStartFileFunc();
73 Constant *getIncrementIndirectCounterFunc();
74 Constant *getEmitFunctionFunc();
75 Constant *getEmitArcsFunc();
76 Constant *getEndFileFunc();
78 // Create or retrieve an i32 state value that is used to represent the
79 // pred block number for certain non-trivial edges.
80 GlobalVariable *getEdgeStateValue();
82 // Produce a table of pointers to counters, by predecessor and successor
84 GlobalVariable *buildEdgeLookupTable(Function *F,
85 GlobalVariable *Counter,
86 const UniqueVector<BasicBlock *> &Preds,
87 const UniqueVector<BasicBlock *> &Succs);
89 // Add the function to write out all our counters to the global destructor
91 void insertCounterWriteout(ArrayRef<std::pair<GlobalVariable*, MDNode*> >);
92 void insertIndirectCounterIncrement();
94 std::string mangleName(DICompileUnit CU, const char *NewStem);
99 bool UseExtraChecksum;
106 char GCOVProfiler::ID = 0;
107 INITIALIZE_PASS(GCOVProfiler, "insert-gcov-profiling",
108 "Insert instrumentation for GCOV profiling", false, false)
110 ModulePass *llvm::createGCOVProfilerPass(bool EmitNotes, bool EmitData,
112 bool UseExtraChecksum) {
113 return new GCOVProfiler(EmitNotes, EmitData, Use402Format, UseExtraChecksum);
119 static const char *LinesTag;
120 static const char *FunctionTag;
121 static const char *BlockTag;
122 static const char *EdgeTag;
126 void writeBytes(const char *Bytes, int Size) {
127 os->write(Bytes, Size);
130 void write(uint32_t i) {
131 writeBytes(reinterpret_cast<char*>(&i), 4);
134 // Returns the length measured in 4-byte blocks that will be used to
135 // represent this string in a GCOV file
136 unsigned lengthOfGCOVString(StringRef s) {
137 // A GCOV string is a length, followed by a NUL, then between 0 and 3 NULs
138 // padding out to the next 4-byte word. The length is measured in 4-byte
139 // words including padding, not bytes of actual string.
140 return (s.size() / 4) + 1;
143 void writeGCOVString(StringRef s) {
144 uint32_t Len = lengthOfGCOVString(s);
146 writeBytes(s.data(), s.size());
148 // Write 1 to 4 bytes of NUL padding.
149 assert((unsigned)(4 - (s.size() % 4)) > 0);
150 assert((unsigned)(4 - (s.size() % 4)) <= 4);
151 writeBytes("\0\0\0\0", 4 - (s.size() % 4));
156 const char *GCOVRecord::LinesTag = "\0\0\x45\x01";
157 const char *GCOVRecord::FunctionTag = "\0\0\0\1";
158 const char *GCOVRecord::BlockTag = "\0\0\x41\x01";
159 const char *GCOVRecord::EdgeTag = "\0\0\x43\x01";
164 // Constructed only by requesting it from a GCOVBlock, this object stores a
165 // list of line numbers and a single filename, representing lines that belong
167 class GCOVLines : public GCOVRecord {
169 void addLine(uint32_t Line) {
170 Lines.push_back(Line);
174 // Here 2 = 1 for string length + 1 for '0' id#.
175 return lengthOfGCOVString(Filename) + 2 + Lines.size();
180 writeGCOVString(Filename);
181 for (int i = 0, e = Lines.size(); i != e; ++i)
185 GCOVLines(StringRef F, raw_ostream *os)
192 SmallVector<uint32_t, 32> Lines;
195 // Represent a basic block in GCOV. Each block has a unique number in the
196 // function, number of lines belonging to each block, and a set of edges to
198 class GCOVBlock : public GCOVRecord {
200 GCOVLines &getFile(StringRef Filename) {
201 GCOVLines *&Lines = LinesByFile[Filename];
203 Lines = new GCOVLines(Filename, os);
208 void addEdge(GCOVBlock &Successor) {
209 OutEdges.push_back(&Successor);
214 for (StringMap<GCOVLines *>::iterator I = LinesByFile.begin(),
215 E = LinesByFile.end(); I != E; ++I) {
216 Len += I->second->length();
219 writeBytes(LinesTag, 4);
222 for (StringMap<GCOVLines *>::iterator I = LinesByFile.begin(),
223 E = LinesByFile.end(); I != E; ++I)
224 I->second->writeOut();
230 DeleteContainerSeconds(LinesByFile);
234 friend class GCOVFunction;
236 GCOVBlock(uint32_t Number, raw_ostream *os)
242 StringMap<GCOVLines *> LinesByFile;
243 SmallVector<GCOVBlock *, 4> OutEdges;
246 // A function has a unique identifier, a checksum (we leave as zero) and a
247 // set of blocks and a map of edges between blocks. This is the only GCOV
248 // object users can construct, the blocks and lines will be rooted here.
249 class GCOVFunction : public GCOVRecord {
251 GCOVFunction(DISubprogram SP, raw_ostream *os,
252 bool Use402Format, bool UseExtraChecksum) {
255 Function *F = SP.getFunction();
256 DEBUG(dbgs() << "Function: " << F->getName() << "\n");
258 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
259 Blocks[BB] = new GCOVBlock(i++, os);
261 ReturnBlock = new GCOVBlock(i++, os);
263 writeBytes(FunctionTag, 4);
264 uint32_t BlockLen = 1 + 1 + 1 + lengthOfGCOVString(SP.getName()) +
265 1 + lengthOfGCOVString(SP.getFilename()) + 1;
266 if (UseExtraChecksum)
269 uint32_t Ident = reinterpret_cast<intptr_t>((MDNode*)SP);
271 write(0); // lineno checksum
272 if (UseExtraChecksum)
273 write(0); // cfg checksum
274 writeGCOVString(SP.getName());
275 writeGCOVString(SP.getFilename());
276 write(SP.getLineNumber());
280 DeleteContainerSeconds(Blocks);
284 GCOVBlock &getBlock(BasicBlock *BB) {
288 GCOVBlock &getReturnBlock() {
293 // Emit count of blocks.
294 writeBytes(BlockTag, 4);
295 write(Blocks.size() + 1);
296 for (int i = 0, e = Blocks.size() + 1; i != e; ++i) {
297 write(0); // No flags on our blocks.
299 DEBUG(dbgs() << Blocks.size() << " blocks.\n");
301 // Emit edges between blocks.
302 for (DenseMap<BasicBlock *, GCOVBlock *>::iterator I = Blocks.begin(),
303 E = Blocks.end(); I != E; ++I) {
304 GCOVBlock &Block = *I->second;
305 if (Block.OutEdges.empty()) continue;
307 writeBytes(EdgeTag, 4);
308 write(Block.OutEdges.size() * 2 + 1);
310 for (int i = 0, e = Block.OutEdges.size(); i != e; ++i) {
311 DEBUG(dbgs() << Block.Number << " -> " << Block.OutEdges[i]->Number
313 write(Block.OutEdges[i]->Number);
314 write(0); // no flags
318 // Emit lines for each block.
319 for (DenseMap<BasicBlock *, GCOVBlock *>::iterator I = Blocks.begin(),
320 E = Blocks.end(); I != E; ++I) {
321 I->second->writeOut();
326 DenseMap<BasicBlock *, GCOVBlock *> Blocks;
327 GCOVBlock *ReturnBlock;
331 std::string GCOVProfiler::mangleName(DICompileUnit CU, const char *NewStem) {
332 SmallString<128> Filename = CU.getFilename();
333 bool AsString = false;
335 if (NamedMDNode *GCov = M->getNamedMetadata("llvm.gcov")) {
336 for (int i = 0, e = GCov->getNumOperands(); i != e; ++i) {
337 MDNode *N = GCov->getOperand(i);
338 if (N->getNumOperands() != 2) continue;
339 MDString *GCovFile = dyn_cast<MDString>(N->getOperand(0));
340 MDNode *CompileUnit = dyn_cast<MDNode>(N->getOperand(1));
341 if (!GCovFile || !CompileUnit) continue;
342 if (CompileUnit == CU) {
343 Filename = GCovFile->getString();
350 if (sys::path::is_relative(Filename.c_str())) {
351 SmallString<128> FullPath = CU.getDirectory();
352 sys::path::append(FullPath, Filename.begin(), Filename.end());
356 sys::path::replace_extension(Filename, NewStem);
359 return sys::path::filename(Filename.str());
361 return Filename.str();
364 bool GCOVProfiler::runOnModule(Module &M) {
366 Ctx = &M.getContext();
368 if (EmitNotes) emitGCNO();
369 if (EmitData) return emitProfileArcs();
373 void GCOVProfiler::emitGCNO() {
374 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
375 if (!CU_Nodes) return;
377 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
378 // Each compile unit gets its own .gcno file. This means that whether we run
379 // this pass over the original .o's as they're produced, or run it after
380 // LTO, we'll generate the same .gcno files.
382 DICompileUnit CU(CU_Nodes->getOperand(i));
383 std::string ErrorInfo;
384 raw_fd_ostream out(mangleName(CU, "gcno").c_str(), ErrorInfo,
385 raw_fd_ostream::F_Binary);
387 out.write("oncg*404MVLL", 12);
389 out.write("oncg*204MVLL", 12);
391 DIArray SPs = CU.getSubprograms();
392 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i) {
393 DISubprogram SP(SPs.getElement(i));
394 if (!SP.Verify()) continue;
396 Function *F = SP.getFunction();
398 GCOVFunction Func(SP, &out, Use402Format, UseExtraChecksum);
400 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
401 GCOVBlock &Block = Func.getBlock(BB);
402 TerminatorInst *TI = BB->getTerminator();
403 if (int successors = TI->getNumSuccessors()) {
404 for (int i = 0; i != successors; ++i) {
405 Block.addEdge(Func.getBlock(TI->getSuccessor(i)));
407 } else if (isa<ReturnInst>(TI)) {
408 Block.addEdge(Func.getReturnBlock());
412 for (BasicBlock::iterator I = BB->begin(), IE = BB->end();
414 const DebugLoc &Loc = I->getDebugLoc();
415 if (Loc.isUnknown()) continue;
416 if (Line == Loc.getLine()) continue;
417 Line = Loc.getLine();
418 if (SP != getDISubprogram(Loc.getScope(*Ctx))) continue;
420 GCOVLines &Lines = Block.getFile(SP.getFilename());
421 Lines.addLine(Loc.getLine());
426 out.write("\0\0\0\0\0\0\0\0", 8); // EOF
431 bool GCOVProfiler::emitProfileArcs() {
432 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
433 if (!CU_Nodes) return false;
436 bool InsertIndCounterIncrCode = false;
437 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
438 DICompileUnit CU(CU_Nodes->getOperand(i));
439 DIArray SPs = CU.getSubprograms();
440 SmallVector<std::pair<GlobalVariable *, MDNode *>, 8> CountersBySP;
441 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i) {
442 DISubprogram SP(SPs.getElement(i));
443 if (!SP.Verify()) continue;
444 Function *F = SP.getFunction();
446 if (!Result) Result = true;
448 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
449 TerminatorInst *TI = BB->getTerminator();
450 if (isa<ReturnInst>(TI))
453 Edges += TI->getNumSuccessors();
456 ArrayType *CounterTy =
457 ArrayType::get(Type::getInt64Ty(*Ctx), Edges);
458 GlobalVariable *Counters =
459 new GlobalVariable(*M, CounterTy, false,
460 GlobalValue::InternalLinkage,
461 Constant::getNullValue(CounterTy),
463 CountersBySP.push_back(std::make_pair(Counters, (MDNode*)SP));
465 UniqueVector<BasicBlock *> ComplexEdgePreds;
466 UniqueVector<BasicBlock *> ComplexEdgeSuccs;
469 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
470 TerminatorInst *TI = BB->getTerminator();
471 int Successors = isa<ReturnInst>(TI) ? 1 : TI->getNumSuccessors();
473 IRBuilder<> Builder(TI);
475 if (Successors == 1) {
476 Value *Counter = Builder.CreateConstInBoundsGEP2_64(Counters, 0,
478 Value *Count = Builder.CreateLoad(Counter);
479 Count = Builder.CreateAdd(Count,
480 ConstantInt::get(Type::getInt64Ty(*Ctx),1));
481 Builder.CreateStore(Count, Counter);
482 } else if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
483 Value *Sel = Builder.CreateSelect(
485 ConstantInt::get(Type::getInt64Ty(*Ctx), Edge),
486 ConstantInt::get(Type::getInt64Ty(*Ctx), Edge + 1));
487 SmallVector<Value *, 2> Idx;
488 Idx.push_back(Constant::getNullValue(Type::getInt64Ty(*Ctx)));
490 Value *Counter = Builder.CreateInBoundsGEP(Counters, Idx);
491 Value *Count = Builder.CreateLoad(Counter);
492 Count = Builder.CreateAdd(Count,
493 ConstantInt::get(Type::getInt64Ty(*Ctx),1));
494 Builder.CreateStore(Count, Counter);
496 ComplexEdgePreds.insert(BB);
497 for (int i = 0; i != Successors; ++i)
498 ComplexEdgeSuccs.insert(TI->getSuccessor(i));
504 if (!ComplexEdgePreds.empty()) {
505 GlobalVariable *EdgeTable =
506 buildEdgeLookupTable(F, Counters,
507 ComplexEdgePreds, ComplexEdgeSuccs);
508 GlobalVariable *EdgeState = getEdgeStateValue();
510 Type *Int32Ty = Type::getInt32Ty(*Ctx);
511 for (int i = 0, e = ComplexEdgePreds.size(); i != e; ++i) {
512 IRBuilder<> Builder(ComplexEdgePreds[i+1]->getTerminator());
513 Builder.CreateStore(ConstantInt::get(Int32Ty, i), EdgeState);
515 for (int i = 0, e = ComplexEdgeSuccs.size(); i != e; ++i) {
516 // call runtime to perform increment
517 BasicBlock::iterator InsertPt =
518 ComplexEdgeSuccs[i+1]->getFirstInsertionPt();
519 IRBuilder<> Builder(InsertPt);
520 Value *CounterPtrArray =
521 Builder.CreateConstInBoundsGEP2_64(EdgeTable, 0,
522 i * ComplexEdgePreds.size());
524 // Build code to increment the counter.
525 InsertIndCounterIncrCode = true;
526 Builder.CreateCall2(getIncrementIndirectCounterFunc(),
527 EdgeState, CounterPtrArray);
532 insertCounterWriteout(CountersBySP);
535 if (InsertIndCounterIncrCode)
536 insertIndirectCounterIncrement();
541 // All edges with successors that aren't branches are "complex", because it
542 // requires complex logic to pick which counter to update.
543 GlobalVariable *GCOVProfiler::buildEdgeLookupTable(
545 GlobalVariable *Counters,
546 const UniqueVector<BasicBlock *> &Preds,
547 const UniqueVector<BasicBlock *> &Succs) {
548 // TODO: support invoke, threads. We rely on the fact that nothing can modify
549 // the whole-Module pred edge# between the time we set it and the time we next
550 // read it. Threads and invoke make this untrue.
552 // emit [(succs * preds) x i64*], logically [succ x [pred x i64*]].
553 Type *Int64PtrTy = Type::getInt64PtrTy(*Ctx);
554 ArrayType *EdgeTableTy = ArrayType::get(
555 Int64PtrTy, Succs.size() * Preds.size());
557 Constant **EdgeTable = new Constant*[Succs.size() * Preds.size()];
558 Constant *NullValue = Constant::getNullValue(Int64PtrTy);
559 for (int i = 0, ie = Succs.size() * Preds.size(); i != ie; ++i)
560 EdgeTable[i] = NullValue;
563 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
564 TerminatorInst *TI = BB->getTerminator();
565 int Successors = isa<ReturnInst>(TI) ? 1 : TI->getNumSuccessors();
566 if (Successors > 1 && !isa<BranchInst>(TI) && !isa<ReturnInst>(TI)) {
567 for (int i = 0; i != Successors; ++i) {
568 BasicBlock *Succ = TI->getSuccessor(i);
569 IRBuilder<> builder(Succ);
570 Value *Counter = builder.CreateConstInBoundsGEP2_64(Counters, 0,
572 EdgeTable[((Succs.idFor(Succ)-1) * Preds.size()) +
573 (Preds.idFor(BB)-1)] = cast<Constant>(Counter);
579 ArrayRef<Constant*> V(&EdgeTable[0], Succs.size() * Preds.size());
580 GlobalVariable *EdgeTableGV =
582 *M, EdgeTableTy, true, GlobalValue::InternalLinkage,
583 ConstantArray::get(EdgeTableTy, V),
584 "__llvm_gcda_edge_table");
585 EdgeTableGV->setUnnamedAddr(true);
589 Constant *GCOVProfiler::getStartFileFunc() {
590 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx),
591 Type::getInt8PtrTy(*Ctx), false);
592 return M->getOrInsertFunction("llvm_gcda_start_file", FTy);
595 Constant *GCOVProfiler::getIncrementIndirectCounterFunc() {
596 Type *Int32Ty = Type::getInt32Ty(*Ctx);
597 Type *Int64Ty = Type::getInt64Ty(*Ctx);
599 Int32Ty->getPointerTo(), // uint32_t *predecessor
600 Int64Ty->getPointerTo()->getPointerTo() // uint64_t **counters
602 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
603 return M->getOrInsertFunction("__llvm_gcov_indirect_counter_increment", FTy);
606 Constant *GCOVProfiler::getEmitFunctionFunc() {
608 Type::getInt32Ty(*Ctx), // uint32_t ident
609 Type::getInt8PtrTy(*Ctx), // const char *function_name
611 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
612 return M->getOrInsertFunction("llvm_gcda_emit_function", FTy);
615 Constant *GCOVProfiler::getEmitArcsFunc() {
617 Type::getInt32Ty(*Ctx), // uint32_t num_counters
618 Type::getInt64PtrTy(*Ctx), // uint64_t *counters
620 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx),
622 return M->getOrInsertFunction("llvm_gcda_emit_arcs", FTy);
625 Constant *GCOVProfiler::getEndFileFunc() {
626 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
627 return M->getOrInsertFunction("llvm_gcda_end_file", FTy);
630 GlobalVariable *GCOVProfiler::getEdgeStateValue() {
631 GlobalVariable *GV = M->getGlobalVariable("__llvm_gcov_global_state_pred");
633 GV = new GlobalVariable(*M, Type::getInt32Ty(*Ctx), false,
634 GlobalValue::InternalLinkage,
635 ConstantInt::get(Type::getInt32Ty(*Ctx),
637 "__llvm_gcov_global_state_pred");
638 GV->setUnnamedAddr(true);
643 void GCOVProfiler::insertCounterWriteout(
644 ArrayRef<std::pair<GlobalVariable *, MDNode *> > CountersBySP) {
645 FunctionType *WriteoutFTy =
646 FunctionType::get(Type::getVoidTy(*Ctx), false);
647 Function *WriteoutF = Function::Create(WriteoutFTy,
648 GlobalValue::InternalLinkage,
649 "__llvm_gcov_writeout", M);
650 WriteoutF->setUnnamedAddr(true);
651 BasicBlock *BB = BasicBlock::Create(*Ctx, "", WriteoutF);
652 IRBuilder<> Builder(BB);
654 Constant *StartFile = getStartFileFunc();
655 Constant *EmitFunction = getEmitFunctionFunc();
656 Constant *EmitArcs = getEmitArcsFunc();
657 Constant *EndFile = getEndFileFunc();
659 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
661 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
662 DICompileUnit compile_unit(CU_Nodes->getOperand(i));
663 std::string FilenameGcda = mangleName(compile_unit, "gcda");
664 Builder.CreateCall(StartFile,
665 Builder.CreateGlobalStringPtr(FilenameGcda));
666 for (ArrayRef<std::pair<GlobalVariable *, MDNode *> >::iterator
667 I = CountersBySP.begin(), E = CountersBySP.end();
669 DISubprogram SP(I->second);
670 intptr_t ident = reinterpret_cast<intptr_t>(I->second);
671 Builder.CreateCall2(EmitFunction,
672 ConstantInt::get(Type::getInt32Ty(*Ctx), ident),
673 Builder.CreateGlobalStringPtr(SP.getName()));
675 GlobalVariable *GV = I->first;
677 cast<ArrayType>(GV->getType()->getElementType())->getNumElements();
678 Builder.CreateCall2(EmitArcs,
679 ConstantInt::get(Type::getInt32Ty(*Ctx), Arcs),
680 Builder.CreateConstGEP2_64(GV, 0, 0));
682 Builder.CreateCall(EndFile);
685 Builder.CreateRetVoid();
687 // Create a small bit of code that registers the "__llvm_gcov_writeout"
688 // function to be executed at exit.
689 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
690 Function *F = Function::Create(FTy, GlobalValue::InternalLinkage,
691 "__llvm_gcov_init", M);
692 F->setUnnamedAddr(true);
693 F->setLinkage(GlobalValue::InternalLinkage);
694 F->addFnAttr(Attribute::NoInline);
696 BB = BasicBlock::Create(*Ctx, "entry", F);
697 Builder.SetInsertPoint(BB);
699 FTy = FunctionType::get(Type::getInt32Ty(*Ctx),
700 PointerType::get(FTy, 0), false);
701 Constant *AtExitFn = M->getOrInsertFunction("atexit", FTy);
702 Builder.CreateCall(AtExitFn, WriteoutF);
703 Builder.CreateRetVoid();
705 appendToGlobalCtors(*M, F, 0);
708 void GCOVProfiler::insertIndirectCounterIncrement() {
710 cast<Function>(GCOVProfiler::getIncrementIndirectCounterFunc());
711 Fn->setUnnamedAddr(true);
712 Fn->setLinkage(GlobalValue::InternalLinkage);
713 Fn->addFnAttr(Attribute::NoInline);
715 Type *Int32Ty = Type::getInt32Ty(*Ctx);
716 Type *Int64Ty = Type::getInt64Ty(*Ctx);
717 Constant *NegOne = ConstantInt::get(Int32Ty, 0xffffffff);
719 // Create basic blocks for function.
720 BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", Fn);
721 IRBuilder<> Builder(BB);
723 BasicBlock *PredNotNegOne = BasicBlock::Create(*Ctx, "", Fn);
724 BasicBlock *CounterEnd = BasicBlock::Create(*Ctx, "", Fn);
725 BasicBlock *Exit = BasicBlock::Create(*Ctx, "exit", Fn);
727 // uint32_t pred = *predecessor;
728 // if (pred == 0xffffffff) return;
729 Argument *Arg = Fn->arg_begin();
730 Arg->setName("predecessor");
731 Value *Pred = Builder.CreateLoad(Arg, "pred");
732 Value *Cond = Builder.CreateICmpEQ(Pred, NegOne);
733 BranchInst::Create(Exit, PredNotNegOne, Cond, BB);
735 Builder.SetInsertPoint(PredNotNegOne);
737 // uint64_t *counter = counters[pred];
738 // if (!counter) return;
739 Value *ZExtPred = Builder.CreateZExt(Pred, Int64Ty);
740 Arg = llvm::next(Fn->arg_begin());
741 Arg->setName("counters");
742 Value *GEP = Builder.CreateGEP(Arg, ZExtPred);
743 Value *Counter = Builder.CreateLoad(GEP, "counter");
744 Cond = Builder.CreateICmpEQ(Counter,
745 Constant::getNullValue(Int64Ty->getPointerTo()));
746 Builder.CreateCondBr(Cond, Exit, CounterEnd);
749 Builder.SetInsertPoint(CounterEnd);
750 Value *Add = Builder.CreateAdd(Builder.CreateLoad(Counter),
751 ConstantInt::get(Int64Ty, 1));
752 Builder.CreateStore(Add, Counter);
753 Builder.CreateBr(Exit);
755 // Fill in the exit block.
756 Builder.SetInsertPoint(Exit);
757 Builder.CreateRetVoid();