llvm-6502/lib/Analysis/ProfileInfoLoader.cpp
2006-11-28 22:46:12 +00:00

277 lines
9.5 KiB
C++

//===- ProfileInfoLoad.cpp - Load profile information from disk -----------===//
//
// 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.
//
//===----------------------------------------------------------------------===//
//
// 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 <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) {
llvm_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) {
llvm_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) {
llvm_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) {
llvm_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) {
llvm_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:
llvm_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()->front() == BlockCounts[i].first)
Counts.push_back(std::make_pair(BlockCounts[i].first->getParent(),
BlockCounts[i].second));
} else {
llvm_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->isExternal())
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) {
llvm_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 {
llvm_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()) {
llvm_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 ()) {
llvm_cerr << "Basic block trace is not available!\n";
return;
}
llvm_cerr << "Basic block trace loading is not implemented yet!\n";
}