llvm-project/llvm/lib/ProfileData/SampleProfWriter.cpp

241 lines
7.8 KiB
C++

//===- SampleProfWriter.cpp - Write LLVM sample profile data --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the class that writes LLVM sample profiles. It
// supports two file formats: text and binary. The textual representation
// is useful for debugging and testing purposes. The binary representation
// is more compact, resulting in smaller file sizes. However, they can
// both be used interchangeably.
//
// See lib/ProfileData/SampleProfReader.cpp for documentation on each of the
// supported formats.
//
//===----------------------------------------------------------------------===//
#include "llvm/ProfileData/SampleProfWriter.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/LineIterator.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Regex.h"
using namespace llvm::sampleprof;
using namespace llvm;
/// \brief Write samples to a text file.
///
/// Note: it may be tempting to implement this in terms of
/// FunctionSamples::print(). Please don't. The dump functionality is intended
/// for debugging and has no specified form.
///
/// The format used here is more structured and deliberate because
/// it needs to be parsed by the SampleProfileReaderText class.
std::error_code SampleProfileWriterText::write(StringRef FName,
const FunctionSamples &S) {
auto &OS = *OutputStream;
OS << FName << ":" << S.getTotalSamples();
if (Indent == 0)
OS << ":" << S.getHeadSamples();
OS << "\n";
SampleSorter<LineLocation, SampleRecord> SortedSamples(S.getBodySamples());
for (const auto &I : SortedSamples.get()) {
LineLocation Loc = I->first;
const SampleRecord &Sample = I->second;
OS.indent(Indent + 1);
if (Loc.Discriminator == 0)
OS << Loc.LineOffset << ": ";
else
OS << Loc.LineOffset << "." << Loc.Discriminator << ": ";
OS << Sample.getSamples();
for (const auto &J : Sample.getCallTargets())
OS << " " << J.first() << ":" << J.second;
OS << "\n";
}
SampleSorter<CallsiteLocation, FunctionSamples> SortedCallsiteSamples(
S.getCallsiteSamples());
Indent += 1;
for (const auto &I : SortedCallsiteSamples.get()) {
CallsiteLocation Loc = I->first;
const FunctionSamples &CalleeSamples = I->second;
OS.indent(Indent);
if (Loc.Discriminator == 0)
OS << Loc.LineOffset << ": ";
else
OS << Loc.LineOffset << "." << Loc.Discriminator << ": ";
if (std::error_code EC = write(Loc.CalleeName, CalleeSamples))
return EC;
}
Indent -= 1;
return sampleprof_error::success;
}
std::error_code SampleProfileWriterBinary::writeNameIdx(StringRef FName) {
const auto &ret = NameTable.find(FName);
if (ret == NameTable.end())
return sampleprof_error::truncated_name_table;
encodeULEB128(ret->second, *OutputStream);
return sampleprof_error::success;
}
void SampleProfileWriterBinary::addName(StringRef FName) {
auto NextIdx = NameTable.size();
NameTable.insert(std::make_pair(FName, NextIdx));
}
void SampleProfileWriterBinary::addNames(const FunctionSamples &S) {
// Add all the names in indirect call targets.
for (const auto &I : S.getBodySamples()) {
const SampleRecord &Sample = I.second;
for (const auto &J : Sample.getCallTargets())
addName(J.first());
}
// Recursively add all the names for inlined callsites.
for (const auto &J : S.getCallsiteSamples()) {
CallsiteLocation Loc = J.first;
const FunctionSamples &CalleeSamples = J.second;
addName(Loc.CalleeName);
addNames(CalleeSamples);
}
}
std::error_code SampleProfileWriterBinary::writeHeader(
const StringMap<FunctionSamples> &ProfileMap) {
auto &OS = *OutputStream;
// Write file magic identifier.
encodeULEB128(SPMagic(), OS);
encodeULEB128(SPVersion(), OS);
// Generate the name table for all the functions referenced in the profile.
for (const auto &I : ProfileMap) {
addName(I.first());
addNames(I.second);
}
// Write out the name table.
encodeULEB128(NameTable.size(), OS);
for (auto N : NameTable) {
OS << N.first;
encodeULEB128(0, OS);
}
return sampleprof_error::success;
}
std::error_code SampleProfileWriterBinary::writeBody(StringRef FName,
const FunctionSamples &S) {
auto &OS = *OutputStream;
if (std::error_code EC = writeNameIdx(FName))
return EC;
encodeULEB128(S.getTotalSamples(), OS);
// Emit all the body samples.
encodeULEB128(S.getBodySamples().size(), OS);
for (const auto &I : S.getBodySamples()) {
LineLocation Loc = I.first;
const SampleRecord &Sample = I.second;
encodeULEB128(Loc.LineOffset, OS);
encodeULEB128(Loc.Discriminator, OS);
encodeULEB128(Sample.getSamples(), OS);
encodeULEB128(Sample.getCallTargets().size(), OS);
for (const auto &J : Sample.getCallTargets()) {
StringRef Callee = J.first();
uint64_t CalleeSamples = J.second;
if (std::error_code EC = writeNameIdx(Callee))
return EC;
encodeULEB128(CalleeSamples, OS);
}
}
// Recursively emit all the callsite samples.
encodeULEB128(S.getCallsiteSamples().size(), OS);
for (const auto &J : S.getCallsiteSamples()) {
CallsiteLocation Loc = J.first;
const FunctionSamples &CalleeSamples = J.second;
encodeULEB128(Loc.LineOffset, OS);
encodeULEB128(Loc.Discriminator, OS);
if (std::error_code EC = writeBody(Loc.CalleeName, CalleeSamples))
return EC;
}
return sampleprof_error::success;
}
/// \brief Write samples of a top-level function to a binary file.
///
/// \returns true if the samples were written successfully, false otherwise.
std::error_code SampleProfileWriterBinary::write(StringRef FName,
const FunctionSamples &S) {
encodeULEB128(S.getHeadSamples(), *OutputStream);
return writeBody(FName, S);
}
/// \brief Create a sample profile file writer based on the specified format.
///
/// \param Filename The file to create.
///
/// \param Writer The writer to instantiate according to the specified format.
///
/// \param Format Encoding format for the profile file.
///
/// \returns an error code indicating the status of the created writer.
ErrorOr<std::unique_ptr<SampleProfileWriter>>
SampleProfileWriter::create(StringRef Filename, SampleProfileFormat Format) {
std::error_code EC;
std::unique_ptr<raw_ostream> OS;
if (Format == SPF_Binary)
OS.reset(new raw_fd_ostream(Filename, EC, sys::fs::F_None));
else
OS.reset(new raw_fd_ostream(Filename, EC, sys::fs::F_Text));
if (EC)
return EC;
return create(OS, Format);
}
/// \brief Create a sample profile stream writer based on the specified format.
///
/// \param OS The output stream to store the profile data to.
///
/// \param Writer The writer to instantiate according to the specified format.
///
/// \param Format Encoding format for the profile file.
///
/// \returns an error code indicating the status of the created writer.
ErrorOr<std::unique_ptr<SampleProfileWriter>>
SampleProfileWriter::create(std::unique_ptr<raw_ostream> &OS,
SampleProfileFormat Format) {
std::error_code EC;
std::unique_ptr<SampleProfileWriter> Writer;
if (Format == SPF_Binary)
Writer.reset(new SampleProfileWriterBinary(OS));
else if (Format == SPF_Text)
Writer.reset(new SampleProfileWriterText(OS));
else if (Format == SPF_GCC)
EC = sampleprof_error::unsupported_writing_format;
else
EC = sampleprof_error::unrecognized_format;
if (EC)
return EC;
return std::move(Writer);
}