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[PGO] Add PGO to LDC. Supported for LLVM >= 3.7

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Add the commandline options -fprofile-instr-generate[=filename] and -profile-instr-use=filename
-fprofile-instr-generate
-- Add instrumentation on branches, switches, and function entry; uses LLVM's InstrProf pass.
-- Link to profile runtime that writes instrumentation counters to a file.
-fprofile-instr-use
-- Read profile data from a file and apply branch weights to branches and switches, and annotate functions with entrycount in LLVM IR.
-- Functions with low or high entrycount are marked with 'cold' or 'inlinehint'.

The only statement type without PGO yet is "try-finally".

A new pragma, `pragma(LDC_profile_instr, [ true | false ])`, is added to selectively disable/enable instrumentation of functions (granularity = whole functions).

The runtime library ldc-profile-rt is a copy of LLVM compiler-rt lib/profile. It has to be exactly in-sync with the LLVM version, and thus we need a copy for each PGO-supported LLVM (>=3.7).
import ldc.profile for a D interface to ldc-profile-rt (for example to reset execution counts after a program startup phase).

The instrumentation data is mainly passed on to LLVM: function-entry counts and branch counts/probabilities. LDC marks functions as hot when "execution count is 30% of the maximum function execution count", and marks functions as cold if their count is 1% of maximum function execution count.

The source of LLVM's llvm-profdata tool is hereby included in LDCs repository (different source for each LLVM version), and the binary is included in the install bin folder.
The executable is named "ldc-profdata" to avoid clashing with llvm-profdata on the same machine. This is needed because profdata executable has to be in-sync with the LLVM version used to build LDC.

Maintenance burden: for trunk LLVM, we have to keep ldc-profile-rt and llvm-profdata in sync. There is no diff with upstream; but because of active development there are the occasional API changes.
This commit is contained in:
Johan Engelen 2015-11-17 00:52:59 +01:00 • committed by Johan Engelen
parent a81ac7d790
commit e0d9c58443
99 changed files with 11857 additions and 64 deletions
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utils/llvm-profdata-3.8.cpp Normal file
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//===- llvm-profdata.cpp - LLVM profile data tool -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// llvm-profdata merges .profdata files.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/ProfileData/InstrProfReader.h"
#include "llvm/ProfileData/InstrProfWriter.h"
#include "llvm/ProfileData/SampleProfReader.h"
#include "llvm/ProfileData/SampleProfWriter.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <tuple>
using namespace llvm;
enum ProfileFormat { PF_None = 0, PF_Text, PF_Binary, PF_GCC };
static void exitWithError(const Twine &Message, StringRef Whence = "",
StringRef Hint = "") {
errs() << "error: ";
if (!Whence.empty())
errs() << Whence << ": ";
errs() << Message << "\n";
if (!Hint.empty())
errs() << Hint << "\n";
::exit(1);
}
static void exitWithErrorCode(const std::error_code &Error,
StringRef Whence = "") {
if (Error.category() == instrprof_category()) {
instrprof_error instrError = static_cast<instrprof_error>(Error.value());
if (instrError == instrprof_error::unrecognized_format) {
// Hint for common error of forgetting -sample for sample profiles.
exitWithError(Error.message(), Whence,
"Perhaps you forgot to use the -sample option?");
}
}
exitWithError(Error.message(), Whence);
}
namespace {
enum ProfileKinds { instr, sample };
}
static void handleMergeWriterError(std::error_code &Error,
StringRef WhenceFile = "",
StringRef WhenceFunction = "",
bool ShowHint = true) {
if (!WhenceFile.empty())
errs() << WhenceFile << ": ";
if (!WhenceFunction.empty())
errs() << WhenceFunction << ": ";
errs() << Error.message() << "\n";
if (ShowHint) {
StringRef Hint = "";
if (Error.category() == instrprof_category()) {
instrprof_error instrError = static_cast<instrprof_error>(Error.value());
switch (instrError) {
case instrprof_error::hash_mismatch:
case instrprof_error::count_mismatch:
case instrprof_error::value_site_count_mismatch:
Hint = "Make sure that all profile data to be merged is generated "
"from the same binary.";
break;
default:
break;
}
}
if (!Hint.empty())
errs() << Hint << "\n";
}
}
struct WeightedFile {
StringRef Filename;
uint64_t Weight;
WeightedFile() {}
WeightedFile(StringRef F, uint64_t W) : Filename{F}, Weight{W} {}
};
typedef SmallVector<WeightedFile, 5> WeightedFileVector;
static void mergeInstrProfile(const WeightedFileVector &Inputs,
StringRef OutputFilename,
ProfileFormat OutputFormat) {
if (OutputFilename.compare("-") == 0)
exitWithError("Cannot write indexed profdata format to stdout.");
if (OutputFormat != PF_Binary && OutputFormat != PF_Text)
exitWithError("Unknown format is specified.");
std::error_code EC;
raw_fd_ostream Output(OutputFilename.data(), EC, sys::fs::F_None);
if (EC)
exitWithErrorCode(EC, OutputFilename);
InstrProfWriter Writer;
SmallSet<std::error_code, 4> WriterErrorCodes;
for (const auto &Input : Inputs) {
auto ReaderOrErr = InstrProfReader::create(Input.Filename);
if (std::error_code ec = ReaderOrErr.getError())
exitWithErrorCode(ec, Input.Filename);
auto Reader = std::move(ReaderOrErr.get());
for (auto &I : *Reader) {
if (std::error_code EC = Writer.addRecord(std::move(I), Input.Weight)) {
// Only show hint the first time an error occurs.
bool firstTime = WriterErrorCodes.insert(EC).second;
handleMergeWriterError(EC, Input.Filename, I.Name, firstTime);
}
}
if (Reader->hasError())
exitWithErrorCode(Reader->getError(), Input.Filename);
}
if (OutputFormat == PF_Text)
Writer.writeText(Output);
else
Writer.write(Output);
}
static sampleprof::SampleProfileFormat FormatMap[] = {
sampleprof::SPF_None, sampleprof::SPF_Text, sampleprof::SPF_Binary,
sampleprof::SPF_GCC};
static void mergeSampleProfile(const WeightedFileVector &Inputs,
StringRef OutputFilename,
ProfileFormat OutputFormat) {
using namespace sampleprof;
auto WriterOrErr =
SampleProfileWriter::create(OutputFilename, FormatMap[OutputFormat]);
if (std::error_code EC = WriterOrErr.getError())
exitWithErrorCode(EC, OutputFilename);
auto Writer = std::move(WriterOrErr.get());
StringMap<FunctionSamples> ProfileMap;
SmallVector<std::unique_ptr<sampleprof::SampleProfileReader>, 5> Readers;
for (const auto &Input : Inputs) {
auto ReaderOrErr =
SampleProfileReader::create(Input.Filename, getGlobalContext());
if (std::error_code EC = ReaderOrErr.getError())
exitWithErrorCode(EC, Input.Filename);
// We need to keep the readers around until after all the files are
// read so that we do not lose the function names stored in each
// reader's memory. The function names are needed to write out the
// merged profile map.
Readers.push_back(std::move(ReaderOrErr.get()));
const auto Reader = Readers.back().get();
if (std::error_code EC = Reader->read())
exitWithErrorCode(EC, Input.Filename);
StringMap<FunctionSamples> &Profiles = Reader->getProfiles();
for (StringMap<FunctionSamples>::iterator I = Profiles.begin(),
E = Profiles.end();
I != E; ++I) {
StringRef FName = I->first();
FunctionSamples &Samples = I->second;
sampleprof_error Result = ProfileMap[FName].merge(Samples, Input.Weight);
if (Result != sampleprof_error::success) {
std::error_code EC = make_error_code(Result);
handleMergeWriterError(EC, Input.Filename, FName);
}
}
}
Writer->write(ProfileMap);
}
static WeightedFile parseWeightedFile(const StringRef &WeightedFilename) {
StringRef WeightStr, FileName;
std::tie(WeightStr, FileName) = WeightedFilename.split(',');
uint64_t Weight;
if (WeightStr.getAsInteger(10, Weight) || Weight < 1)
exitWithError("Input weight must be a positive integer.");
if (!sys::fs::exists(FileName))
exitWithErrorCode(make_error_code(errc::no_such_file_or_directory),
FileName);
return WeightedFile(FileName, Weight);
}
static int merge_main(int argc, const char *argv[]) {
cl::list<std::string> InputFilenames(cl::Positional,
cl::desc("<filename...>"));
cl::list<std::string> WeightedInputFilenames("weighted-input",
cl::desc("<weight>,<filename>"));
cl::opt<std::string> OutputFilename("output", cl::value_desc("output"),
cl::init("-"), cl::Required,
cl::desc("Output file"));
cl::alias OutputFilenameA("o", cl::desc("Alias for --output"),
cl::aliasopt(OutputFilename));
cl::opt<ProfileKinds> ProfileKind(
cl::desc("Profile kind:"), cl::init(instr),
cl::values(clEnumVal(instr, "Instrumentation profile (default)"),
clEnumVal(sample, "Sample profile"), clEnumValEnd));
cl::opt<ProfileFormat> OutputFormat(
cl::desc("Format of output profile"), cl::init(PF_Binary),
cl::values(clEnumValN(PF_Binary, "binary", "Binary encoding (default)"),
clEnumValN(PF_Text, "text", "Text encoding"),
clEnumValN(PF_GCC, "gcc",
"GCC encoding (only meaningful for -sample)"),
clEnumValEnd));
cl::ParseCommandLineOptions(argc, argv, "LLVM profile data merger\n");
if (InputFilenames.empty() && WeightedInputFilenames.empty())
exitWithError("No input files specified. See " +
sys::path::filename(argv[0]) + " -help");
WeightedFileVector WeightedInputs;
for (StringRef Filename : InputFilenames)
WeightedInputs.push_back(WeightedFile(Filename, 1));
for (StringRef WeightedFilename : WeightedInputFilenames)
WeightedInputs.push_back(parseWeightedFile(WeightedFilename));
if (ProfileKind == instr)
mergeInstrProfile(WeightedInputs, OutputFilename, OutputFormat);
else
mergeSampleProfile(WeightedInputs, OutputFilename, OutputFormat);
return 0;
}
static int showInstrProfile(std::string Filename, bool ShowCounts,
bool ShowIndirectCallTargets, bool ShowAllFunctions,
std::string ShowFunction, bool TextFormat,
raw_fd_ostream &OS) {
auto ReaderOrErr = InstrProfReader::create(Filename);
if (std::error_code EC = ReaderOrErr.getError())
exitWithErrorCode(EC, Filename);
auto Reader = std::move(ReaderOrErr.get());
uint64_t MaxFunctionCount = 0, MaxBlockCount = 0;
size_t ShownFunctions = 0, TotalFunctions = 0;
for (const auto &Func : *Reader) {
bool Show =
ShowAllFunctions || (!ShowFunction.empty() &&
Func.Name.find(ShowFunction) != Func.Name.npos);
bool doTextFormatDump = (Show && ShowCounts && TextFormat);
if (doTextFormatDump) {
InstrProfSymtab &Symtab = Reader->getSymtab();
InstrProfWriter::writeRecordInText(Func, Symtab, OS);
continue;
}
++TotalFunctions;
assert(Func.Counts.size() > 0 && "function missing entry counter");
if (Func.Counts[0] > MaxFunctionCount)
MaxFunctionCount = Func.Counts[0];
for (size_t I = 1, E = Func.Counts.size(); I < E; ++I) {
if (Func.Counts[I] > MaxBlockCount)
MaxBlockCount = Func.Counts[I];
}
if (Show) {
if (!ShownFunctions)
OS << "Counters:\n";
++ShownFunctions;
OS << " " << Func.Name << ":\n"
<< " Hash: " << format("0x%016" PRIx64, Func.Hash) << "\n"
<< " Counters: " << Func.Counts.size() << "\n"
<< " Function count: " << Func.Counts[0] << "\n";
if (ShowIndirectCallTargets)
OS << " Indirect Call Site Count: "
<< Func.getNumValueSites(IPVK_IndirectCallTarget) << "\n";
if (ShowCounts) {
OS << " Block counts: [";
for (size_t I = 1, E = Func.Counts.size(); I < E; ++I) {
OS << (I == 1 ? "" : ", ") << Func.Counts[I];
}
OS << "]\n";
}
if (ShowIndirectCallTargets) {
InstrProfSymtab &Symtab = Reader->getSymtab();
uint32_t NS = Func.getNumValueSites(IPVK_IndirectCallTarget);
OS << " Indirect Target Results: \n";
for (size_t I = 0; I < NS; ++I) {
uint32_t NV = Func.getNumValueDataForSite(IPVK_IndirectCallTarget, I);
std::unique_ptr<InstrProfValueData[]> VD =
Func.getValueForSite(IPVK_IndirectCallTarget, I);
for (uint32_t V = 0; V < NV; V++) {
OS << "\t[ " << I << ", ";
OS << Symtab.getFuncName(VD[V].Value) << ", " << VD[V].Count
<< " ]\n";
}
}
}
}
}
if (Reader->hasError())
exitWithErrorCode(Reader->getError(), Filename);
if (ShowCounts && TextFormat)
return 0;
if (ShowAllFunctions || !ShowFunction.empty())
OS << "Functions shown: " << ShownFunctions << "\n";
OS << "Total functions: " << TotalFunctions << "\n";
OS << "Maximum function count: " << MaxFunctionCount << "\n";
OS << "Maximum internal block count: " << MaxBlockCount << "\n";
return 0;
}
static int showSampleProfile(std::string Filename, bool ShowCounts,
bool ShowAllFunctions, std::string ShowFunction,
raw_fd_ostream &OS) {
using namespace sampleprof;
auto ReaderOrErr = SampleProfileReader::create(Filename, getGlobalContext());
if (std::error_code EC = ReaderOrErr.getError())
exitWithErrorCode(EC, Filename);
auto Reader = std::move(ReaderOrErr.get());
if (std::error_code EC = Reader->read())
exitWithErrorCode(EC, Filename);
if (ShowAllFunctions || ShowFunction.empty())
Reader->dump(OS);
else
Reader->dumpFunctionProfile(ShowFunction, OS);
return 0;
}
static int show_main(int argc, const char *argv[]) {
cl::opt<std::string> Filename(cl::Positional, cl::Required,
cl::desc("<profdata-file>"));
cl::opt<bool> ShowCounts("counts", cl::init(false),
cl::desc("Show counter values for shown functions"));
cl::opt<bool> TextFormat(
"text", cl::init(false),
cl::desc("Show instr profile data in text dump format"));
cl::opt<bool> ShowIndirectCallTargets(
"ic-targets", cl::init(false),
cl::desc("Show indirect call site target values for shown functions"));
cl::opt<bool> ShowAllFunctions("all-functions", cl::init(false),
cl::desc("Details for every function"));
cl::opt<std::string> ShowFunction("function",
cl::desc("Details for matching functions"));
cl::opt<std::string> OutputFilename("output", cl::value_desc("output"),
cl::init("-"), cl::desc("Output file"));
cl::alias OutputFilenameA("o", cl::desc("Alias for --output"),
cl::aliasopt(OutputFilename));
cl::opt<ProfileKinds> ProfileKind(
cl::desc("Profile kind:"), cl::init(instr),
cl::values(clEnumVal(instr, "Instrumentation profile (default)"),
clEnumVal(sample, "Sample profile"), clEnumValEnd));
cl::ParseCommandLineOptions(argc, argv, "LLVM profile data summary\n");
if (OutputFilename.empty())
OutputFilename = "-";
std::error_code EC;
raw_fd_ostream OS(OutputFilename.data(), EC, sys::fs::F_Text);
if (EC)
exitWithErrorCode(EC, OutputFilename);
if (ShowAllFunctions && !ShowFunction.empty())
errs() << "warning: -function argument ignored: showing all functions\n";
if (ProfileKind == instr)
return showInstrProfile(Filename, ShowCounts, ShowIndirectCallTargets,
ShowAllFunctions, ShowFunction, TextFormat, OS);
else
return showSampleProfile(Filename, ShowCounts, ShowAllFunctions,
ShowFunction, OS);
}
int main(int argc, const char *argv[]) {
// Print a stack trace if we signal out.
sys::PrintStackTraceOnErrorSignal();
PrettyStackTraceProgram X(argc, argv);
llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
StringRef ProgName(sys::path::filename(argv[0]));
if (argc > 1) {
int (*func)(int, const char *[]) = nullptr;
if (strcmp(argv[1], "merge") == 0)
func = merge_main;
else if (strcmp(argv[1], "show") == 0)
func = show_main;
if (func) {
std::string Invocation(ProgName.str() + " " + argv[1]);
argv[1] = Invocation.c_str();
return func(argc - 1, argv + 1);
}
if (strcmp(argv[1], "-h") == 0 || strcmp(argv[1], "-help") == 0 ||
strcmp(argv[1], "--help") == 0) {
errs() << "OVERVIEW: LLVM profile data tools\n\n"
<< "USAGE: " << ProgName << " <command> [args...]\n"
<< "USAGE: " << ProgName << " <command> -help\n\n"
<< "Available commands: merge, show\n";
return 0;
}
}
if (argc < 2)
errs() << ProgName << ": No command specified!\n";
else
errs() << ProgName << ": Unknown command!\n";
errs() << "USAGE: " << ProgName << " <merge|show> [args...]\n";
return 1;
}