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Diffstat (limited to 'lib/Analysis/ProfileInfoLoader.cpp')
-rw-r--r-- | lib/Analysis/ProfileInfoLoader.cpp | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/lib/Analysis/ProfileInfoLoader.cpp b/lib/Analysis/ProfileInfoLoader.cpp new file mode 100644 index 0000000..3a0a740 --- /dev/null +++ b/lib/Analysis/ProfileInfoLoader.cpp @@ -0,0 +1,277 @@ +//===- ProfileInfoLoad.cpp - Load profile information from disk -----------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// The ProfileInfoLoader class is used to load and represent profiling +// information read in from the dump file. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Analysis/ProfileInfoLoader.h" +#include "llvm/Analysis/ProfileInfoTypes.h" +#include "llvm/Module.h" +#include "llvm/InstrTypes.h" +#include "llvm/Support/Streams.h" +#include <cstdio> +#include <cstdlib> +#include <map> +using namespace llvm; + +// ByteSwap - Byteswap 'Var' if 'Really' is true. +// +static inline unsigned ByteSwap(unsigned Var, bool Really) { + if (!Really) return Var; + return ((Var & (255<< 0)) << 24) | + ((Var & (255<< 8)) << 8) | + ((Var & (255<<16)) >> 8) | + ((Var & (255<<24)) >> 24); +} + +static void ReadProfilingBlock(const char *ToolName, FILE *F, + bool ShouldByteSwap, + std::vector<unsigned> &Data) { + // Read the number of entries... + unsigned NumEntries; + if (fread(&NumEntries, sizeof(unsigned), 1, F) != 1) { + cerr << ToolName << ": data packet truncated!\n"; + perror(0); + exit(1); + } + NumEntries = ByteSwap(NumEntries, ShouldByteSwap); + + // Read the counts... + std::vector<unsigned> TempSpace(NumEntries); + + // Read in the block of data... + if (fread(&TempSpace[0], sizeof(unsigned)*NumEntries, 1, F) != 1) { + cerr << ToolName << ": data packet truncated!\n"; + perror(0); + exit(1); + } + + // Make sure we have enough space... + if (Data.size() < NumEntries) + Data.resize(NumEntries); + + // Accumulate the data we just read into the data. + if (!ShouldByteSwap) { + for (unsigned i = 0; i != NumEntries; ++i) + Data[i] += TempSpace[i]; + } else { + for (unsigned i = 0; i != NumEntries; ++i) + Data[i] += ByteSwap(TempSpace[i], true); + } +} + +// ProfileInfoLoader ctor - Read the specified profiling data file, exiting the +// program if the file is invalid or broken. +// +ProfileInfoLoader::ProfileInfoLoader(const char *ToolName, + const std::string &Filename, + Module &TheModule) : M(TheModule) { + FILE *F = fopen(Filename.c_str(), "r"); + if (F == 0) { + cerr << ToolName << ": Error opening '" << Filename << "': "; + perror(0); + exit(1); + } + + // Keep reading packets until we run out of them. + unsigned PacketType; + while (fread(&PacketType, sizeof(unsigned), 1, F) == 1) { + // If the low eight bits of the packet are zero, we must be dealing with an + // endianness mismatch. Byteswap all words read from the profiling + // information. + bool ShouldByteSwap = (char)PacketType == 0; + PacketType = ByteSwap(PacketType, ShouldByteSwap); + + switch (PacketType) { + case ArgumentInfo: { + unsigned ArgLength; + if (fread(&ArgLength, sizeof(unsigned), 1, F) != 1) { + cerr << ToolName << ": arguments packet truncated!\n"; + perror(0); + exit(1); + } + ArgLength = ByteSwap(ArgLength, ShouldByteSwap); + + // Read in the arguments... + std::vector<char> Chars(ArgLength+4); + + if (ArgLength) + if (fread(&Chars[0], (ArgLength+3) & ~3, 1, F) != 1) { + cerr << ToolName << ": arguments packet truncated!\n"; + perror(0); + exit(1); + } + CommandLines.push_back(std::string(&Chars[0], &Chars[ArgLength])); + break; + } + + case FunctionInfo: + ReadProfilingBlock(ToolName, F, ShouldByteSwap, FunctionCounts); + break; + + case BlockInfo: + ReadProfilingBlock(ToolName, F, ShouldByteSwap, BlockCounts); + break; + + case EdgeInfo: + ReadProfilingBlock(ToolName, F, ShouldByteSwap, EdgeCounts); + break; + + case BBTraceInfo: + ReadProfilingBlock(ToolName, F, ShouldByteSwap, BBTrace); + break; + + default: + cerr << ToolName << ": Unknown packet type #" << PacketType << "!\n"; + exit(1); + } + } + + fclose(F); +} + + +// getFunctionCounts - This method is used by consumers of function counting +// information. If we do not directly have function count information, we +// compute it from other, more refined, types of profile information. +// +void ProfileInfoLoader::getFunctionCounts(std::vector<std::pair<Function*, + unsigned> > &Counts) { + if (FunctionCounts.empty()) { + if (hasAccurateBlockCounts()) { + // Synthesize function frequency information from the number of times + // their entry blocks were executed. + std::vector<std::pair<BasicBlock*, unsigned> > BlockCounts; + getBlockCounts(BlockCounts); + + for (unsigned i = 0, e = BlockCounts.size(); i != e; ++i) + if (&BlockCounts[i].first->getParent()->getEntryBlock() == + BlockCounts[i].first) + Counts.push_back(std::make_pair(BlockCounts[i].first->getParent(), + BlockCounts[i].second)); + } else { + cerr << "Function counts are not available!\n"; + } + return; + } + + unsigned Counter = 0; + for (Module::iterator I = M.begin(), E = M.end(); + I != E && Counter != FunctionCounts.size(); ++I) + if (!I->isDeclaration()) + Counts.push_back(std::make_pair(I, FunctionCounts[Counter++])); +} + +// getBlockCounts - This method is used by consumers of block counting +// information. If we do not directly have block count information, we +// compute it from other, more refined, types of profile information. +// +void ProfileInfoLoader::getBlockCounts(std::vector<std::pair<BasicBlock*, + unsigned> > &Counts) { + if (BlockCounts.empty()) { + if (hasAccurateEdgeCounts()) { + // Synthesize block count information from edge frequency information. + // The block execution frequency is equal to the sum of the execution + // frequency of all outgoing edges from a block. + // + // If a block has no successors, this will not be correct, so we have to + // special case it. :( + std::vector<std::pair<Edge, unsigned> > EdgeCounts; + getEdgeCounts(EdgeCounts); + + std::map<BasicBlock*, unsigned> InEdgeFreqs; + + BasicBlock *LastBlock = 0; + TerminatorInst *TI = 0; + for (unsigned i = 0, e = EdgeCounts.size(); i != e; ++i) { + if (EdgeCounts[i].first.first != LastBlock) { + LastBlock = EdgeCounts[i].first.first; + TI = LastBlock->getTerminator(); + Counts.push_back(std::make_pair(LastBlock, 0)); + } + Counts.back().second += EdgeCounts[i].second; + unsigned SuccNum = EdgeCounts[i].first.second; + if (SuccNum >= TI->getNumSuccessors()) { + static bool Warned = false; + if (!Warned) { + cerr << "WARNING: profile info doesn't seem to match" + << " the program!\n"; + Warned = true; + } + } else { + // If this successor has no successors of its own, we will never + // compute an execution count for that block. Remember the incoming + // edge frequencies to add later. + BasicBlock *Succ = TI->getSuccessor(SuccNum); + if (Succ->getTerminator()->getNumSuccessors() == 0) + InEdgeFreqs[Succ] += EdgeCounts[i].second; + } + } + + // Now we have to accumulate information for those blocks without + // successors into our table. + for (std::map<BasicBlock*, unsigned>::iterator I = InEdgeFreqs.begin(), + E = InEdgeFreqs.end(); I != E; ++I) { + unsigned i = 0; + for (; i != Counts.size() && Counts[i].first != I->first; ++i) + /*empty*/; + if (i == Counts.size()) Counts.push_back(std::make_pair(I->first, 0)); + Counts[i].second += I->second; + } + + } else { + cerr << "Block counts are not available!\n"; + } + return; + } + + unsigned Counter = 0; + for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) + for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) { + Counts.push_back(std::make_pair(BB, BlockCounts[Counter++])); + if (Counter == BlockCounts.size()) + return; + } +} + +// getEdgeCounts - This method is used by consumers of edge counting +// information. If we do not directly have edge count information, we compute +// it from other, more refined, types of profile information. +// +void ProfileInfoLoader::getEdgeCounts(std::vector<std::pair<Edge, + unsigned> > &Counts) { + if (EdgeCounts.empty()) { + cerr << "Edge counts not available, and no synthesis " + << "is implemented yet!\n"; + return; + } + + unsigned Counter = 0; + for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) + for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) + for (unsigned i = 0, e = BB->getTerminator()->getNumSuccessors(); + i != e; ++i) { + Counts.push_back(std::make_pair(Edge(BB, i), EdgeCounts[Counter++])); + if (Counter == EdgeCounts.size()) + return; + } +} + +// getBBTrace - This method is used by consumers of basic-block trace +// information. +// +void ProfileInfoLoader::getBBTrace(std::vector<BasicBlock *> &Trace) { + if (BBTrace.empty ()) { + cerr << "Basic block trace is not available!\n"; + return; + } + cerr << "Basic block trace loading is not implemented yet!\n"; +} |