mirror of
https://github.com/c64scene-ar/llvm-6502.git
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a4c4c0e129
necessary since gcov counts transitions between blocks. It can't see if you've run every line in a straight-line function, so we add an edge for it to notice. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129905 91177308-0d34-0410-b5e6-96231b3b80d8
543 lines
18 KiB
C++
543 lines
18 KiB
C++
//===- GCOVProfiling.cpp - Insert edge counters for gcov profiling --------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This pass implements GCOV-style profiling. When this pass is run it emits
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// "gcno" files next to the existing source, and instruments the code that runs
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// to records the edges between blocks that run and emit a complementary "gcda"
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// file on exit.
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "insert-gcov-profiling"
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#include "ProfilingUtils.h"
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#include "llvm/Transforms/Instrumentation.h"
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#include "llvm/Analysis/DebugInfo.h"
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#include "llvm/Module.h"
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#include "llvm/Pass.h"
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#include "llvm/Instructions.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/DebugLoc.h"
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#include "llvm/Support/InstIterator.h"
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#include "llvm/Support/IRBuilder.h"
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#include "llvm/Support/PathV2.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/ADT/StringMap.h"
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#include "llvm/ADT/UniqueVector.h"
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#include <string>
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#include <utility>
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using namespace llvm;
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namespace {
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class GCOVProfiler : public ModulePass {
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bool runOnModule(Module &M);
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public:
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static char ID;
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GCOVProfiler()
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: ModulePass(ID), EmitNotes(true), EmitData(true) {
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initializeGCOVProfilerPass(*PassRegistry::getPassRegistry());
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}
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GCOVProfiler(bool EmitNotes, bool EmitData)
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: ModulePass(ID), EmitNotes(EmitNotes), EmitData(EmitData) {
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assert((EmitNotes || EmitData) && "GCOVProfiler asked to do nothing?");
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initializeGCOVProfilerPass(*PassRegistry::getPassRegistry());
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}
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virtual const char *getPassName() const {
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return "GCOV Profiler";
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}
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private:
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// Create the GCNO files for the Module based on DebugInfo.
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void EmitGCNO(DebugInfoFinder &DIF);
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// Modify the program to track transitions along edges and call into the
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// profiling runtime to emit .gcda files when run.
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bool EmitProfileArcs(DebugInfoFinder &DIF);
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// Get pointers to the functions in the runtime library.
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Constant *getStartFileFunc();
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Constant *getEmitFunctionFunc();
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Constant *getEmitArcsFunc();
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Constant *getEndFileFunc();
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// Add the function to write out all our counters to the global destructor
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// list.
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void InsertCounterWriteout(DebugInfoFinder &,
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SmallVector<std::pair<GlobalVariable *,
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uint32_t>, 8> &);
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bool EmitNotes;
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bool EmitData;
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Module *Mod;
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LLVMContext *Ctx;
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};
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}
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char GCOVProfiler::ID = 0;
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INITIALIZE_PASS(GCOVProfiler, "insert-gcov-profiling",
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"Insert instrumentation for GCOV profiling", false, false)
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ModulePass *llvm::createGCOVProfilerPass(bool EmitNotes, bool EmitData) {
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return new GCOVProfiler(EmitNotes, EmitData);
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}
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static DISubprogram FindSubprogram(DIScope scope) {
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while (!scope.isSubprogram()) {
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assert(scope.isLexicalBlock() &&
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"Debug location not lexical block or subprogram");
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scope = DILexicalBlock(scope).getContext();
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}
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return DISubprogram(scope);
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}
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namespace {
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class GCOVRecord {
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protected:
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static const char *lines_tag;
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static const char *function_tag;
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static const char *block_tag;
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static const char *edge_tag;
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GCOVRecord() {}
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void WriteBytes(const char *b, int size) {
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os->write(b, size);
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}
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void Write(uint32_t i) {
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WriteBytes(reinterpret_cast<char*>(&i), 4);
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}
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// Returns the length measured in 4-byte blocks that will be used to
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// represent this string in a GCOV file
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unsigned LengthOfGCOVString(StringRef s) {
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// A GCOV string is a length, followed by a NUL, then between 0 and 3 NULs
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// padding out to the next 4-byte word. The length is measured in 4-byte
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// words including padding, not bytes of actual string.
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return (s.size() + 5) / 4;
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}
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void WriteGCOVString(StringRef s) {
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uint32_t len = LengthOfGCOVString(s);
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Write(len);
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WriteBytes(s.data(), s.size());
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// Write 1 to 4 bytes of NUL padding.
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assert((unsigned)(5 - ((s.size() + 1) % 4)) > 0);
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assert((unsigned)(5 - ((s.size() + 1) % 4)) <= 4);
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WriteBytes("\0\0\0\0", 5 - ((s.size() + 1) % 4));
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}
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raw_ostream *os;
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};
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const char *GCOVRecord::lines_tag = "\0\0\x45\x01";
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const char *GCOVRecord::function_tag = "\0\0\0\1";
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const char *GCOVRecord::block_tag = "\0\0\x41\x01";
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const char *GCOVRecord::edge_tag = "\0\0\x43\x01";
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class GCOVFunction;
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class GCOVBlock;
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// Constructed only by requesting it from a GCOVBlock, this object stores a
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// list of line numbers and a single filename, representing lines that belong
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// to the block.
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class GCOVLines : public GCOVRecord {
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public:
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void AddLine(uint32_t line) {
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lines.push_back(line);
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}
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uint32_t Length() {
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return LengthOfGCOVString(filename) + 2 + lines.size();
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}
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private:
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friend class GCOVBlock;
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GCOVLines(std::string filename, raw_ostream *os)
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: filename(filename) {
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this->os = os;
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}
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std::string filename;
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SmallVector<uint32_t, 32> lines;
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};
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// Represent a basic block in GCOV. Each block has a unique number in the
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// function, number of lines belonging to each block, and a set of edges to
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// other blocks.
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class GCOVBlock : public GCOVRecord {
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public:
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GCOVLines &GetFile(std::string filename) {
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GCOVLines *&lines = lines_by_file[filename];
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if (!lines) {
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lines = new GCOVLines(filename, os);
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}
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return *lines;
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}
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void AddEdge(GCOVBlock &successor) {
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out_edges.push_back(&successor);
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}
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void WriteOut() {
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uint32_t len = 3;
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for (StringMap<GCOVLines *>::iterator I = lines_by_file.begin(),
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E = lines_by_file.end(); I != E; ++I) {
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len += I->second->Length();
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}
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WriteBytes(lines_tag, 4);
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Write(len);
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Write(number);
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for (StringMap<GCOVLines *>::iterator I = lines_by_file.begin(),
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E = lines_by_file.end(); I != E; ++I) {
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Write(0);
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WriteGCOVString(I->second->filename);
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for (int i = 0, e = I->second->lines.size(); i != e; ++i) {
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Write(I->second->lines[i]);
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}
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}
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Write(0);
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Write(0);
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}
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~GCOVBlock() {
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DeleteContainerSeconds(lines_by_file);
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}
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private:
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friend class GCOVFunction;
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GCOVBlock(uint32_t number, raw_ostream *os)
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: number(number) {
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this->os = os;
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}
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uint32_t number;
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BasicBlock *block;
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StringMap<GCOVLines *> lines_by_file;
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SmallVector<GCOVBlock *, 4> out_edges;
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};
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// A function has a unique identifier, a checksum (we leave as zero) and a
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// set of blocks and a map of edges between blocks. This is the only GCOV
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// object users can construct, the blocks and lines will be rooted here.
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class GCOVFunction : public GCOVRecord {
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public:
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GCOVFunction(DISubprogram SP, raw_ostream *os) {
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this->os = os;
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Function *F = SP.getFunction();
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uint32_t i = 0;
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for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
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blocks[BB] = new GCOVBlock(i++, os);
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}
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return_block = new GCOVBlock(i++, os);
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WriteBytes(function_tag, 4);
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uint32_t block_len = 1 + 1 + 1 + LengthOfGCOVString(SP.getName()) +
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1 + LengthOfGCOVString(SP.getFilename()) + 1;
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Write(block_len);
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uint32_t ident = reinterpret_cast<intptr_t>((MDNode*)SP);
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Write(ident);
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Write(0); // checksum
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WriteGCOVString(SP.getName());
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WriteGCOVString(SP.getFilename());
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Write(SP.getLineNumber());
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}
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~GCOVFunction() {
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DeleteContainerSeconds(blocks);
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delete return_block;
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}
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GCOVBlock &GetBlock(BasicBlock *BB) {
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return *blocks[BB];
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}
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GCOVBlock &GetReturnBlock() {
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return *return_block;
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}
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void WriteOut() {
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// Emit count of blocks.
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WriteBytes(block_tag, 4);
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Write(blocks.size() + 1);
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for (int i = 0, e = blocks.size() + 1; i != e; ++i) {
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Write(0); // No flags on our blocks.
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}
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// Emit edges between blocks.
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for (DenseMap<BasicBlock *, GCOVBlock *>::iterator I = blocks.begin(),
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E = blocks.end(); I != E; ++I) {
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GCOVBlock &block = *I->second;
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if (block.out_edges.empty()) continue;
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WriteBytes(edge_tag, 4);
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Write(block.out_edges.size() * 2 + 1);
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Write(block.number);
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for (int i = 0, e = block.out_edges.size(); i != e; ++i) {
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Write(block.out_edges[i]->number);
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Write(0); // no flags
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}
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}
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// Emit lines for each block.
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for (DenseMap<BasicBlock *, GCOVBlock *>::iterator I = blocks.begin(),
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E = blocks.end(); I != E; ++I) {
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I->second->WriteOut();
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}
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}
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private:
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DenseMap<BasicBlock *, GCOVBlock *> blocks;
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GCOVBlock *return_block;
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};
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}
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// Replace the stem of a file, or add one if missing.
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static std::string ReplaceStem(std::string orig_filename, std::string new_stem){
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return (sys::path::stem(orig_filename) + "." + new_stem).str();
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}
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bool GCOVProfiler::runOnModule(Module &M) {
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Mod = &M;
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Ctx = &M.getContext();
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DebugInfoFinder DIF;
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DIF.processModule(*Mod);
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if (EmitNotes) EmitGCNO(DIF);
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if (EmitData) return EmitProfileArcs(DIF);
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return false;
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}
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void GCOVProfiler::EmitGCNO(DebugInfoFinder &DIF) {
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DenseMap<const MDNode *, raw_fd_ostream *> gcno_files;
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for (DebugInfoFinder::iterator I = DIF.compile_unit_begin(),
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E = DIF.compile_unit_end(); I != E; ++I) {
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// Each compile unit gets its own .gcno file. This means that whether we run
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// this pass over the original .o's as they're produced, or run it after
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// LTO, we'll generate the same .gcno files.
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DICompileUnit CU(*I);
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raw_fd_ostream *&Out = gcno_files[CU];
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std::string ErrorInfo;
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Out = new raw_fd_ostream(ReplaceStem(CU.getFilename(), "gcno").c_str(),
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ErrorInfo, raw_fd_ostream::F_Binary);
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Out->write("oncg*404MVLL", 12);
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}
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for (DebugInfoFinder::iterator SPI = DIF.subprogram_begin(),
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SPE = DIF.subprogram_end(); SPI != SPE; ++SPI) {
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DISubprogram SP(*SPI);
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raw_fd_ostream *&os = gcno_files[SP.getCompileUnit()];
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GCOVFunction function(SP, os);
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Function *F = SP.getFunction();
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for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
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GCOVBlock &block = function.GetBlock(BB);
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TerminatorInst *TI = BB->getTerminator();
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if (int successors = TI->getNumSuccessors()) {
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for (int i = 0; i != successors; ++i) {
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block.AddEdge(function.GetBlock(TI->getSuccessor(i)));
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}
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} else if (isa<ReturnInst>(TI)) {
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block.AddEdge(function.GetReturnBlock());
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}
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uint32_t line = 0;
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for (BasicBlock::iterator I = BB->begin(), IE = BB->end(); I != IE; ++I) {
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const DebugLoc &loc = I->getDebugLoc();
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if (loc.isUnknown()) continue;
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if (line == loc.getLine()) continue;
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line = loc.getLine();
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if (SP != FindSubprogram(DIScope(loc.getScope(*Ctx)))) continue;
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GCOVLines &lines = block.GetFile(SP.getFilename());
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lines.AddLine(loc.getLine());
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}
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}
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function.WriteOut();
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}
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for (DenseMap<const MDNode *, raw_fd_ostream *>::iterator
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I = gcno_files.begin(), E = gcno_files.end(); I != E; ++I) {
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raw_fd_ostream *&Out = I->second;
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Out->write("\0\0\0\0\0\0\0\0", 8); // EOF
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Out->close();
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delete Out;
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}
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}
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bool GCOVProfiler::EmitProfileArcs(DebugInfoFinder &DIF) {
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if (DIF.subprogram_begin() == DIF.subprogram_end())
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return false;
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SmallVector<std::pair<GlobalVariable *, uint32_t>, 8> counters_by_ident;
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for (DebugInfoFinder::iterator SPI = DIF.subprogram_begin(),
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SPE = DIF.subprogram_end(); SPI != SPE; ++SPI) {
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DISubprogram SP(*SPI);
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Function *F = SP.getFunction();
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unsigned edges = 0;
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for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
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TerminatorInst *TI = BB->getTerminator();
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if (isa<ReturnInst>(TI))
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++edges;
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else
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edges += TI->getNumSuccessors();
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}
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const ArrayType *counter_type =
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ArrayType::get(Type::getInt64Ty(*Ctx), edges);
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GlobalVariable *counter =
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new GlobalVariable(*Mod, counter_type, false,
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GlobalValue::InternalLinkage,
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Constant::getNullValue(counter_type),
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"__llvm_gcov_ctr", 0, false, 0);
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counters_by_ident.push_back(
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std::make_pair(counter, reinterpret_cast<intptr_t>((MDNode*)SP)));
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UniqueVector<BasicBlock *> complex_edge_preds;
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UniqueVector<BasicBlock *> complex_edge_succs;
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unsigned edge_num = 0;
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for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
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TerminatorInst *TI = BB->getTerminator();
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int successors = isa<ReturnInst>(TI) ? 1 : TI->getNumSuccessors();
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if (successors) {
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IRBuilder<> builder(TI);
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if (successors == 1) {
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Value *ctr = builder.CreateConstInBoundsGEP2_64(counter, 0, edge_num);
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Value *count = builder.CreateLoad(ctr);
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count = builder.CreateAdd(count,
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ConstantInt::get(Type::getInt64Ty(*Ctx),1));
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builder.CreateStore(count, ctr);
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} else if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
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Value *sel = builder.CreateSelect(
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BI->getCondition(),
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ConstantInt::get(Type::getInt64Ty(*Ctx), edge_num),
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ConstantInt::get(Type::getInt64Ty(*Ctx), edge_num + 1));
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SmallVector<Value *, 2> idx;
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idx.push_back(Constant::getNullValue(Type::getInt64Ty(*Ctx)));
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idx.push_back(sel);
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Value *ctr = builder.CreateInBoundsGEP(counter,
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idx.begin(), idx.end());
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Value *count = builder.CreateLoad(ctr);
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count = builder.CreateAdd(count,
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ConstantInt::get(Type::getInt64Ty(*Ctx),1));
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builder.CreateStore(count, ctr);
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} else {
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complex_edge_preds.insert(BB);
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for (int i = 0; i != successors; ++i) {
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complex_edge_succs.insert(TI->getSuccessor(i));
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}
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}
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edge_num += successors;
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}
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}
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// TODO: support switch, invoke, indirectbr
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if (!complex_edge_preds.empty()) {
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// emit a [preds x [succs x i64*]].
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for (int i = 0, e = complex_edge_preds.size(); i != e; ++i) {
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// call runtime to state save
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}
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for (int i = 0, e = complex_edge_succs.size(); i != e; ++i) {
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// call runtime to perform increment
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}
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}
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}
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InsertCounterWriteout(DIF, counters_by_ident);
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return true;
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}
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Constant *GCOVProfiler::getStartFileFunc() {
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const Type *Args[1] = { Type::getInt8PtrTy(*Ctx) };
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const FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx),
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Args, false);
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return Mod->getOrInsertFunction("llvm_gcda_start_file", FTy);
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}
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Constant *GCOVProfiler::getEmitFunctionFunc() {
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const Type *Args[1] = { Type::getInt32Ty(*Ctx) };
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const FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx),
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Args, false);
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return Mod->getOrInsertFunction("llvm_gcda_emit_function", FTy);
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}
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Constant *GCOVProfiler::getEmitArcsFunc() {
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const Type *Args[] = {
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Type::getInt32Ty(*Ctx), // uint32_t num_counters
|
|
Type::getInt64PtrTy(*Ctx), // uint64_t *counters
|
|
};
|
|
const FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx),
|
|
Args, false);
|
|
return Mod->getOrInsertFunction("llvm_gcda_emit_arcs", FTy);
|
|
}
|
|
|
|
Constant *GCOVProfiler::getEndFileFunc() {
|
|
const FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
|
|
return Mod->getOrInsertFunction("llvm_gcda_end_file", FTy);
|
|
}
|
|
|
|
void GCOVProfiler::InsertCounterWriteout(
|
|
DebugInfoFinder &DIF,
|
|
SmallVector<std::pair<GlobalVariable *, uint32_t>, 8> &counters_by_ident) {
|
|
|
|
const FunctionType *WriteoutFTy =
|
|
FunctionType::get(Type::getVoidTy(*Ctx), false);
|
|
Function *WriteoutF = Function::Create(WriteoutFTy,
|
|
GlobalValue::InternalLinkage,
|
|
"__llvm_gcda_writeout", Mod);
|
|
WriteoutF->setUnnamedAddr(true);
|
|
BasicBlock *BB = BasicBlock::Create(*Ctx, "", WriteoutF);
|
|
IRBuilder<> builder(BB);
|
|
|
|
Constant *StartFile = getStartFileFunc();
|
|
Constant *EmitFunction = getEmitFunctionFunc();
|
|
Constant *EmitArcs = getEmitArcsFunc();
|
|
Constant *EndFile = getEndFileFunc();
|
|
|
|
for (DebugInfoFinder::iterator CUI = DIF.compile_unit_begin(),
|
|
CUE = DIF.compile_unit_end(); CUI != CUE; ++CUI) {
|
|
DICompileUnit compile_unit(*CUI);
|
|
std::string filename_gcda = ReplaceStem(compile_unit.getFilename(), "gcda");
|
|
builder.CreateCall(StartFile,
|
|
builder.CreateGlobalStringPtr(filename_gcda));
|
|
for (SmallVector<std::pair<GlobalVariable *, uint32_t>, 8>::iterator
|
|
I = counters_by_ident.begin(), E = counters_by_ident.end();
|
|
I != E; ++I) {
|
|
builder.CreateCall(EmitFunction, ConstantInt::get(Type::getInt32Ty(*Ctx),
|
|
I->second));
|
|
GlobalVariable *GV = I->first;
|
|
unsigned num_arcs =
|
|
cast<ArrayType>(GV->getType()->getElementType())->getNumElements();
|
|
builder.CreateCall2(
|
|
EmitArcs,
|
|
ConstantInt::get(Type::getInt32Ty(*Ctx), num_arcs),
|
|
builder.CreateConstGEP2_64(GV, 0, 0));
|
|
}
|
|
builder.CreateCall(EndFile);
|
|
}
|
|
builder.CreateRetVoid();
|
|
|
|
InsertProfilingShutdownCall(WriteoutF, Mod);
|
|
}
|