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llvm-mirror/lib/ProfileData/InstrProfReader.cpp
Rong Xu 005085c634 [PGO] Supporting code for always instrumenting entry block 
This patch includes the supporting code that enables always
instrumenting the function entry block by default.

This patch will NOT the default behavior.

It adds a variant bit in the profile version, adds new directives in
text profile format, and changes llvm-profdata tool accordingly.

This patch is a split of D83024 (https://reviews.llvm.org/D83024)
Many test changes from D83024 are also included.

Differential Revision: https://reviews.llvm.org/D84261
2020-07-22 15:01:53 -07:00

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//===- InstrProfReader.cpp - Instrumented profiling reader ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains support for reading profiling data for clang's
// instrumentation based PGO and coverage.
//
//===----------------------------------------------------------------------===//
#include "llvm/ProfileData/InstrProfReader.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/ProfileSummary.h"
#include "llvm/ProfileData/InstrProf.h"
#include "llvm/ProfileData/ProfileCommon.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SymbolRemappingReader.h"
#include "llvm/Support/SwapByteOrder.h"
#include <algorithm>
#include <cctype>
#include <cstddef>
#include <cstdint>
#include <limits>
#include <memory>
#include <system_error>
#include <utility>
#include <vector>
using namespace llvm;
static Expected<std::unique_ptr<MemoryBuffer>>
setupMemoryBuffer(const Twine &Path) {
ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
MemoryBuffer::getFileOrSTDIN(Path);
if (std::error_code EC = BufferOrErr.getError())
return errorCodeToError(EC);
return std::move(BufferOrErr.get());
}
static Error initializeReader(InstrProfReader &Reader) {
return Reader.readHeader();
}
Expected<std::unique_ptr<InstrProfReader>>
InstrProfReader::create(const Twine &Path) {
// Set up the buffer to read.
auto BufferOrError = setupMemoryBuffer(Path);
if (Error E = BufferOrError.takeError())
return std::move(E);
return InstrProfReader::create(std::move(BufferOrError.get()));
}
Expected<std::unique_ptr<InstrProfReader>>
InstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer) {
// Sanity check the buffer.
if (uint64_t(Buffer->getBufferSize()) > std::numeric_limits<uint64_t>::max())
return make_error<InstrProfError>(instrprof_error::too_large);
if (Buffer->getBufferSize() == 0)
return make_error<InstrProfError>(instrprof_error::empty_raw_profile);
std::unique_ptr<InstrProfReader> Result;
// Create the reader.
if (IndexedInstrProfReader::hasFormat(*Buffer))
Result.reset(new IndexedInstrProfReader(std::move(Buffer)));
else if (RawInstrProfReader64::hasFormat(*Buffer))
Result.reset(new RawInstrProfReader64(std::move(Buffer)));
else if (RawInstrProfReader32::hasFormat(*Buffer))
Result.reset(new RawInstrProfReader32(std::move(Buffer)));
else if (TextInstrProfReader::hasFormat(*Buffer))
Result.reset(new TextInstrProfReader(std::move(Buffer)));
else
return make_error<InstrProfError>(instrprof_error::unrecognized_format);
// Initialize the reader and return the result.
if (Error E = initializeReader(*Result))
return std::move(E);
return std::move(Result);
}
Expected<std::unique_ptr<IndexedInstrProfReader>>
IndexedInstrProfReader::create(const Twine &Path, const Twine &RemappingPath) {
// Set up the buffer to read.
auto BufferOrError = setupMemoryBuffer(Path);
if (Error E = BufferOrError.takeError())
return std::move(E);
// Set up the remapping buffer if requested.
std::unique_ptr<MemoryBuffer> RemappingBuffer;
std::string RemappingPathStr = RemappingPath.str();
if (!RemappingPathStr.empty()) {
auto RemappingBufferOrError = setupMemoryBuffer(RemappingPathStr);
if (Error E = RemappingBufferOrError.takeError())
return std::move(E);
RemappingBuffer = std::move(RemappingBufferOrError.get());
}
return IndexedInstrProfReader::create(std::move(BufferOrError.get()),
std::move(RemappingBuffer));
}
Expected<std::unique_ptr<IndexedInstrProfReader>>
IndexedInstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer,
std::unique_ptr<MemoryBuffer> RemappingBuffer) {
// Sanity check the buffer.
if (uint64_t(Buffer->getBufferSize()) > std::numeric_limits<uint64_t>::max())
return make_error<InstrProfError>(instrprof_error::too_large);
// Create the reader.
if (!IndexedInstrProfReader::hasFormat(*Buffer))
return make_error<InstrProfError>(instrprof_error::bad_magic);
auto Result = std::make_unique<IndexedInstrProfReader>(
std::move(Buffer), std::move(RemappingBuffer));
// Initialize the reader and return the result.
if (Error E = initializeReader(*Result))
return std::move(E);
return std::move(Result);
}
void InstrProfIterator::Increment() {
if (auto E = Reader->readNextRecord(Record)) {
// Handle errors in the reader.
InstrProfError::take(std::move(E));
*this = InstrProfIterator();
}
}
bool TextInstrProfReader::hasFormat(const MemoryBuffer &Buffer) {
// Verify that this really looks like plain ASCII text by checking a
// 'reasonable' number of characters (up to profile magic size).
size_t count = std::min(Buffer.getBufferSize(), sizeof(uint64_t));
StringRef buffer = Buffer.getBufferStart();
return count == 0 ||
std::all_of(buffer.begin(), buffer.begin() + count,
[](char c) { return isPrint(c) || isSpace(c); });
}
// Read the profile variant flag from the header: ":FE" means this is a FE
// generated profile. ":IR" means this is an IR level profile. Other strings
// with a leading ':' will be reported an error format.
Error TextInstrProfReader::readHeader() {
Symtab.reset(new InstrProfSymtab());
bool IsIRInstr = false;
bool IsEntryFirst = false;
bool IsCS = false;
while (Line->startswith(":")) {
StringRef Str = Line->substr(1);
if (Str.equals_lower("ir"))
IsIRInstr = true;
else if (Str.equals_lower("fe"))
IsIRInstr = false;
else if (Str.equals_lower("csir")) {
IsIRInstr = true;
IsCS = true;
} else if (Str.equals_lower("entry_first"))
IsEntryFirst = true;
else if (Str.equals_lower("not_entry_first"))
IsEntryFirst = false;
else
return error(instrprof_error::bad_header);
++Line;
}
IsIRLevelProfile = IsIRInstr;
InstrEntryBBEnabled = IsEntryFirst;
HasCSIRLevelProfile = IsCS;
return success();
}
Error
TextInstrProfReader::readValueProfileData(InstrProfRecord &Record) {
#define CHECK_LINE_END(Line) \
if (Line.is_at_end()) \
return error(instrprof_error::truncated);
#define READ_NUM(Str, Dst) \
if ((Str).getAsInteger(10, (Dst))) \
return error(instrprof_error::malformed);
#define VP_READ_ADVANCE(Val) \
CHECK_LINE_END(Line); \
uint32_t Val; \
READ_NUM((*Line), (Val)); \
Line++;
if (Line.is_at_end())
return success();
uint32_t NumValueKinds;
if (Line->getAsInteger(10, NumValueKinds)) {
// No value profile data
return success();
}
if (NumValueKinds == 0 || NumValueKinds > IPVK_Last + 1)
return error(instrprof_error::malformed);
Line++;
for (uint32_t VK = 0; VK < NumValueKinds; VK++) {
VP_READ_ADVANCE(ValueKind);
if (ValueKind > IPVK_Last)
return error(instrprof_error::malformed);
VP_READ_ADVANCE(NumValueSites);
if (!NumValueSites)
continue;
Record.reserveSites(VK, NumValueSites);
for (uint32_t S = 0; S < NumValueSites; S++) {
VP_READ_ADVANCE(NumValueData);
std::vector<InstrProfValueData> CurrentValues;
for (uint32_t V = 0; V < NumValueData; V++) {
CHECK_LINE_END(Line);
std::pair<StringRef, StringRef> VD = Line->rsplit(':');
uint64_t TakenCount, Value;
if (ValueKind == IPVK_IndirectCallTarget) {
if (InstrProfSymtab::isExternalSymbol(VD.first)) {
Value = 0;
} else {
if (Error E = Symtab->addFuncName(VD.first))
return E;
Value = IndexedInstrProf::ComputeHash(VD.first);
}
} else {
READ_NUM(VD.first, Value);
}
READ_NUM(VD.second, TakenCount);
CurrentValues.push_back({Value, TakenCount});
Line++;
}
Record.addValueData(ValueKind, S, CurrentValues.data(), NumValueData,
nullptr);
}
}
return success();
#undef CHECK_LINE_END
#undef READ_NUM
#undef VP_READ_ADVANCE
}
Error TextInstrProfReader::readNextRecord(NamedInstrProfRecord &Record) {
// Skip empty lines and comments.
while (!Line.is_at_end() && (Line->empty() || Line->startswith("#")))
++Line;
// If we hit EOF while looking for a name, we're done.
if (Line.is_at_end()) {
return error(instrprof_error::eof);
}
// Read the function name.
Record.Name = *Line++;
if (Error E = Symtab->addFuncName(Record.Name))
return error(std::move(E));
// Read the function hash.
if (Line.is_at_end())
return error(instrprof_error::truncated);
if ((Line++)->getAsInteger(0, Record.Hash))
return error(instrprof_error::malformed);
// Read the number of counters.
uint64_t NumCounters;
if (Line.is_at_end())
return error(instrprof_error::truncated);
if ((Line++)->getAsInteger(10, NumCounters))
return error(instrprof_error::malformed);
if (NumCounters == 0)
return error(instrprof_error::malformed);
// Read each counter and fill our internal storage with the values.
Record.Clear();
Record.Counts.reserve(NumCounters);
for (uint64_t I = 0; I < NumCounters; ++I) {
if (Line.is_at_end())
return error(instrprof_error::truncated);
uint64_t Count;
if ((Line++)->getAsInteger(10, Count))
return error(instrprof_error::malformed);
Record.Counts.push_back(Count);
}
// Check if value profile data exists and read it if so.
if (Error E = readValueProfileData(Record))
return error(std::move(E));
return success();
}
template <class IntPtrT>
bool RawInstrProfReader<IntPtrT>::hasFormat(const MemoryBuffer &DataBuffer) {
if (DataBuffer.getBufferSize() < sizeof(uint64_t))
return false;
uint64_t Magic =
*reinterpret_cast<const uint64_t *>(DataBuffer.getBufferStart());
return RawInstrProf::getMagic<IntPtrT>() == Magic ||
sys::getSwappedBytes(RawInstrProf::getMagic<IntPtrT>()) == Magic;
}
template <class IntPtrT>
Error RawInstrProfReader<IntPtrT>::readHeader() {
if (!hasFormat(*DataBuffer))
return error(instrprof_error::bad_magic);
if (DataBuffer->getBufferSize() < sizeof(RawInstrProf::Header))
return error(instrprof_error::bad_header);
auto *Header = reinterpret_cast<const RawInstrProf::Header *>(
DataBuffer->getBufferStart());
ShouldSwapBytes = Header->Magic != RawInstrProf::getMagic<IntPtrT>();
return readHeader(*Header);
}
template <class IntPtrT>
Error RawInstrProfReader<IntPtrT>::readNextHeader(const char *CurrentPos) {
const char *End = DataBuffer->getBufferEnd();
// Skip zero padding between profiles.
while (CurrentPos != End && *CurrentPos == 0)
++CurrentPos;
// If there's nothing left, we're done.
if (CurrentPos == End)
return make_error<InstrProfError>(instrprof_error::eof);
// If there isn't enough space for another header, this is probably just
// garbage at the end of the file.
if (CurrentPos + sizeof(RawInstrProf::Header) > End)
return make_error<InstrProfError>(instrprof_error::malformed);
// The writer ensures each profile is padded to start at an aligned address.
if (reinterpret_cast<size_t>(CurrentPos) % alignof(uint64_t))
return make_error<InstrProfError>(instrprof_error::malformed);
// The magic should have the same byte order as in the previous header.
uint64_t Magic = *reinterpret_cast<const uint64_t *>(CurrentPos);
if (Magic != swap(RawInstrProf::getMagic<IntPtrT>()))
return make_error<InstrProfError>(instrprof_error::bad_magic);
// There's another profile to read, so we need to process the header.
auto *Header = reinterpret_cast<const RawInstrProf::Header *>(CurrentPos);
return readHeader(*Header);
}
template <class IntPtrT>
Error RawInstrProfReader<IntPtrT>::createSymtab(InstrProfSymtab &Symtab) {
if (Error E = Symtab.create(StringRef(NamesStart, NamesSize)))
return error(std::move(E));
for (const RawInstrProf::ProfileData<IntPtrT> *I = Data; I != DataEnd; ++I) {
const IntPtrT FPtr = swap(I->FunctionPointer);
if (!FPtr)
continue;
Symtab.mapAddress(FPtr, I->NameRef);
}
return success();
}
template <class IntPtrT>
Error RawInstrProfReader<IntPtrT>::readHeader(
const RawInstrProf::Header &Header) {
Version = swap(Header.Version);
if (GET_VERSION(Version) != RawInstrProf::Version)
return error(instrprof_error::unsupported_version);
CountersDelta = swap(Header.CountersDelta);
NamesDelta = swap(Header.NamesDelta);
auto DataSize = swap(Header.DataSize);
auto PaddingBytesBeforeCounters = swap(Header.PaddingBytesBeforeCounters);
auto CountersSize = swap(Header.CountersSize);
auto PaddingBytesAfterCounters = swap(Header.PaddingBytesAfterCounters);
NamesSize = swap(Header.NamesSize);
ValueKindLast = swap(Header.ValueKindLast);
auto DataSizeInBytes = DataSize * sizeof(RawInstrProf::ProfileData<IntPtrT>);
auto PaddingSize = getNumPaddingBytes(NamesSize);
ptrdiff_t DataOffset = sizeof(RawInstrProf::Header);
ptrdiff_t CountersOffset =
DataOffset + DataSizeInBytes + PaddingBytesBeforeCounters;
ptrdiff_t NamesOffset = CountersOffset + (sizeof(uint64_t) * CountersSize) +
PaddingBytesAfterCounters;
ptrdiff_t ValueDataOffset = NamesOffset + NamesSize + PaddingSize;
auto *Start = reinterpret_cast<const char *>(&Header);
if (Start + ValueDataOffset > DataBuffer->getBufferEnd())
return error(instrprof_error::bad_header);
Data = reinterpret_cast<const RawInstrProf::ProfileData<IntPtrT> *>(
Start + DataOffset);
DataEnd = Data + DataSize;
CountersStart = reinterpret_cast<const uint64_t *>(Start + CountersOffset);
NamesStart = Start + NamesOffset;
ValueDataStart = reinterpret_cast<const uint8_t *>(Start + ValueDataOffset);
std::unique_ptr<InstrProfSymtab> NewSymtab = std::make_unique<InstrProfSymtab>();
if (Error E = createSymtab(*NewSymtab.get()))
return E;
Symtab = std::move(NewSymtab);
return success();
}
template <class IntPtrT>
Error RawInstrProfReader<IntPtrT>::readName(NamedInstrProfRecord &Record) {
Record.Name = getName(Data->NameRef);
return success();
}
template <class IntPtrT>
Error RawInstrProfReader<IntPtrT>::readFuncHash(NamedInstrProfRecord &Record) {
Record.Hash = swap(Data->FuncHash);
return success();
}
template <class IntPtrT>
Error RawInstrProfReader<IntPtrT>::readRawCounts(
InstrProfRecord &Record) {
uint32_t NumCounters = swap(Data->NumCounters);
IntPtrT CounterPtr = Data->CounterPtr;
if (NumCounters == 0)
return error(instrprof_error::malformed);
auto *NamesStartAsCounter = reinterpret_cast<const uint64_t *>(NamesStart);
ptrdiff_t MaxNumCounters = NamesStartAsCounter - CountersStart;
// Check bounds. Note that the counter pointer embedded in the data record
// may itself be corrupt.
if (MaxNumCounters < 0 || NumCounters > (uint32_t)MaxNumCounters)
return error(instrprof_error::malformed);
ptrdiff_t CounterOffset = getCounterOffset(CounterPtr);
if (CounterOffset < 0 || CounterOffset > MaxNumCounters ||
((uint32_t)CounterOffset + NumCounters) > (uint32_t)MaxNumCounters)
return error(instrprof_error::malformed);
auto RawCounts = makeArrayRef(getCounter(CounterOffset), NumCounters);
if (ShouldSwapBytes) {
Record.Counts.clear();
Record.Counts.reserve(RawCounts.size());
for (uint64_t Count : RawCounts)
Record.Counts.push_back(swap(Count));
} else
Record.Counts = RawCounts;
return success();
}
template <class IntPtrT>
Error RawInstrProfReader<IntPtrT>::readValueProfilingData(
InstrProfRecord &Record) {
Record.clearValueData();
CurValueDataSize = 0;
// Need to match the logic in value profile dumper code in compiler-rt:
uint32_t NumValueKinds = 0;
for (uint32_t I = 0; I < IPVK_Last + 1; I++)
NumValueKinds += (Data->NumValueSites[I] != 0);
if (!NumValueKinds)
return success();
Expected<std::unique_ptr<ValueProfData>> VDataPtrOrErr =
ValueProfData::getValueProfData(
ValueDataStart, (const unsigned char *)DataBuffer->getBufferEnd(),
getDataEndianness());
if (Error E = VDataPtrOrErr.takeError())
return E;
// Note that besides deserialization, this also performs the conversion for
// indirect call targets. The function pointers from the raw profile are
// remapped into function name hashes.
VDataPtrOrErr.get()->deserializeTo(Record, Symtab.get());
CurValueDataSize = VDataPtrOrErr.get()->getSize();
return success();
}
template <class IntPtrT>
Error RawInstrProfReader<IntPtrT>::readNextRecord(NamedInstrProfRecord &Record) {
if (atEnd())
// At this point, ValueDataStart field points to the next header.
if (Error E = readNextHeader(getNextHeaderPos()))
return error(std::move(E));
// Read name ad set it in Record.
if (Error E = readName(Record))
return error(std::move(E));
// Read FuncHash and set it in Record.
if (Error E = readFuncHash(Record))
return error(std::move(E));
// Read raw counts and set Record.
if (Error E = readRawCounts(Record))
return error(std::move(E));
// Read value data and set Record.
if (Error E = readValueProfilingData(Record))
return error(std::move(E));
// Iterate.
advanceData();
return success();
}
namespace llvm {
template class RawInstrProfReader<uint32_t>;
template class RawInstrProfReader<uint64_t>;
} // end namespace llvm
InstrProfLookupTrait::hash_value_type
InstrProfLookupTrait::ComputeHash(StringRef K) {
return IndexedInstrProf::ComputeHash(HashType, K);
}
using data_type = InstrProfLookupTrait::data_type;
using offset_type = InstrProfLookupTrait::offset_type;
bool InstrProfLookupTrait::readValueProfilingData(
const unsigned char *&D, const unsigned char *const End) {
Expected<std::unique_ptr<ValueProfData>> VDataPtrOrErr =
ValueProfData::getValueProfData(D, End, ValueProfDataEndianness);
if (VDataPtrOrErr.takeError())
return false;
VDataPtrOrErr.get()->deserializeTo(DataBuffer.back(), nullptr);
D += VDataPtrOrErr.get()->TotalSize;
return true;
}
data_type InstrProfLookupTrait::ReadData(StringRef K, const unsigned char *D,
offset_type N) {
using namespace support;
// Check if the data is corrupt. If so, don't try to read it.
if (N % sizeof(uint64_t))
return data_type();
DataBuffer.clear();
std::vector<uint64_t> CounterBuffer;
const unsigned char *End = D + N;
while (D < End) {
// Read hash.
if (D + sizeof(uint64_t) >= End)
return data_type();
uint64_t Hash = endian::readNext<uint64_t, little, unaligned>(D);
// Initialize number of counters for GET_VERSION(FormatVersion) == 1.
uint64_t CountsSize = N / sizeof(uint64_t) - 1;
// If format version is different then read the number of counters.
if (GET_VERSION(FormatVersion) != IndexedInstrProf::ProfVersion::Version1) {
if (D + sizeof(uint64_t) > End)
return data_type();
CountsSize = endian::readNext<uint64_t, little, unaligned>(D);
}
// Read counter values.
if (D + CountsSize * sizeof(uint64_t) > End)
return data_type();
CounterBuffer.clear();
CounterBuffer.reserve(CountsSize);
for (uint64_t J = 0; J < CountsSize; ++J)
CounterBuffer.push_back(endian::readNext<uint64_t, little, unaligned>(D));
DataBuffer.emplace_back(K, Hash, std::move(CounterBuffer));
// Read value profiling data.
if (GET_VERSION(FormatVersion) > IndexedInstrProf::ProfVersion::Version2 &&
!readValueProfilingData(D, End)) {
DataBuffer.clear();
return data_type();
}
}
return DataBuffer;
}
template <typename HashTableImpl>
Error InstrProfReaderIndex<HashTableImpl>::getRecords(
StringRef FuncName, ArrayRef<NamedInstrProfRecord> &Data) {
auto Iter = HashTable->find(FuncName);
if (Iter == HashTable->end())
return make_error<InstrProfError>(instrprof_error::unknown_function);
Data = (*Iter);
if (Data.empty())
return make_error<InstrProfError>(instrprof_error::malformed);
return Error::success();
}
template <typename HashTableImpl>
Error InstrProfReaderIndex<HashTableImpl>::getRecords(
ArrayRef<NamedInstrProfRecord> &Data) {
if (atEnd())
return make_error<InstrProfError>(instrprof_error::eof);
Data = *RecordIterator;
if (Data.empty())
return make_error<InstrProfError>(instrprof_error::malformed);
return Error::success();
}
template <typename HashTableImpl>
InstrProfReaderIndex<HashTableImpl>::InstrProfReaderIndex(
const unsigned char *Buckets, const unsigned char *const Payload,
const unsigned char *const Base, IndexedInstrProf::HashT HashType,
uint64_t Version) {
FormatVersion = Version;
HashTable.reset(HashTableImpl::Create(
Buckets, Payload, Base,
typename HashTableImpl::InfoType(HashType, Version)));
RecordIterator = HashTable->data_begin();
}
namespace {
/// A remapper that does not apply any remappings.
class InstrProfReaderNullRemapper : public InstrProfReaderRemapper {
InstrProfReaderIndexBase &Underlying;
public:
InstrProfReaderNullRemapper(InstrProfReaderIndexBase &Underlying)
: Underlying(Underlying) {}
Error getRecords(StringRef FuncName,
ArrayRef<NamedInstrProfRecord> &Data) override {
return Underlying.getRecords(FuncName, Data);
}
};
}
/// A remapper that applies remappings based on a symbol remapping file.
template <typename HashTableImpl>
class llvm::InstrProfReaderItaniumRemapper
: public InstrProfReaderRemapper {
public:
InstrProfReaderItaniumRemapper(
std::unique_ptr<MemoryBuffer> RemapBuffer,
InstrProfReaderIndex<HashTableImpl> &Underlying)
: RemapBuffer(std::move(RemapBuffer)), Underlying(Underlying) {
}
/// Extract the original function name from a PGO function name.
static StringRef extractName(StringRef Name) {
// We can have multiple :-separated pieces; there can be pieces both
// before and after the mangled name. Find the first part that starts
// with '_Z'; we'll assume that's the mangled name we want.
std::pair<StringRef, StringRef> Parts = {StringRef(), Name};
while (true) {
Parts = Parts.second.split(':');
if (Parts.first.startswith("_Z"))
return Parts.first;
if (Parts.second.empty())
return Name;
}
}
/// Given a mangled name extracted from a PGO function name, and a new
/// form for that mangled name, reconstitute the name.
static void reconstituteName(StringRef OrigName, StringRef ExtractedName,
StringRef Replacement,
SmallVectorImpl<char> &Out) {
Out.reserve(OrigName.size() + Replacement.size() - ExtractedName.size());
Out.insert(Out.end(), OrigName.begin(), ExtractedName.begin());
Out.insert(Out.end(), Replacement.begin(), Replacement.end());
Out.insert(Out.end(), ExtractedName.end(), OrigName.end());
}
Error populateRemappings() override {
if (Error E = Remappings.read(*RemapBuffer))
return E;
for (StringRef Name : Underlying.HashTable->keys()) {
StringRef RealName = extractName(Name);
if (auto Key = Remappings.insert(RealName)) {
// FIXME: We could theoretically map the same equivalence class to
// multiple names in the profile data. If that happens, we should
// return NamedInstrProfRecords from all of them.
MappedNames.insert({Key, RealName});
}
}
return Error::success();
}
Error getRecords(StringRef FuncName,
ArrayRef<NamedInstrProfRecord> &Data) override {
StringRef RealName = extractName(FuncName);
if (auto Key = Remappings.lookup(RealName)) {
StringRef Remapped = MappedNames.lookup(Key);
if (!Remapped.empty()) {
if (RealName.begin() == FuncName.begin() &&
RealName.end() == FuncName.end())
FuncName = Remapped;
else {
// Try rebuilding the name from the given remapping.
SmallString<256> Reconstituted;
reconstituteName(FuncName, RealName, Remapped, Reconstituted);
Error E = Underlying.getRecords(Reconstituted, Data);
if (!E)
return E;
// If we failed because the name doesn't exist, fall back to asking
// about the original name.
if (Error Unhandled = handleErrors(
std::move(E), [](std::unique_ptr<InstrProfError> Err) {
return Err->get() == instrprof_error::unknown_function
? Error::success()
: Error(std::move(Err));
}))
return Unhandled;
}
}
}
return Underlying.getRecords(FuncName, Data);
}
private:
/// The memory buffer containing the remapping configuration. Remappings
/// holds pointers into this buffer.
std::unique_ptr<MemoryBuffer> RemapBuffer;
/// The mangling remapper.
SymbolRemappingReader Remappings;
/// Mapping from mangled name keys to the name used for the key in the
/// profile data.
/// FIXME: Can we store a location within the on-disk hash table instead of
/// redoing lookup?
DenseMap<SymbolRemappingReader::Key, StringRef> MappedNames;
/// The real profile data reader.
InstrProfReaderIndex<HashTableImpl> &Underlying;
};
bool IndexedInstrProfReader::hasFormat(const MemoryBuffer &DataBuffer) {
using namespace support;
if (DataBuffer.getBufferSize() < 8)
return false;
uint64_t Magic =
endian::read<uint64_t, little, aligned>(DataBuffer.getBufferStart());
// Verify that it's magical.
return Magic == IndexedInstrProf::Magic;
}
const unsigned char *
IndexedInstrProfReader::readSummary(IndexedInstrProf::ProfVersion Version,
const unsigned char *Cur, bool UseCS) {
using namespace IndexedInstrProf;
using namespace support;
if (Version >= IndexedInstrProf::Version4) {
const IndexedInstrProf::Summary *SummaryInLE =
reinterpret_cast<const IndexedInstrProf::Summary *>(Cur);
uint64_t NFields =
endian::byte_swap<uint64_t, little>(SummaryInLE->NumSummaryFields);
uint64_t NEntries =
endian::byte_swap<uint64_t, little>(SummaryInLE->NumCutoffEntries);
uint32_t SummarySize =
IndexedInstrProf::Summary::getSize(NFields, NEntries);
std::unique_ptr<IndexedInstrProf::Summary> SummaryData =
IndexedInstrProf::allocSummary(SummarySize);
const uint64_t *Src = reinterpret_cast<const uint64_t *>(SummaryInLE);
uint64_t *Dst = reinterpret_cast<uint64_t *>(SummaryData.get());
for (unsigned I = 0; I < SummarySize / sizeof(uint64_t); I++)
Dst[I] = endian::byte_swap<uint64_t, little>(Src[I]);
SummaryEntryVector DetailedSummary;
for (unsigned I = 0; I < SummaryData->NumCutoffEntries; I++) {
const IndexedInstrProf::Summary::Entry &Ent = SummaryData->getEntry(I);
DetailedSummary.emplace_back((uint32_t)Ent.Cutoff, Ent.MinBlockCount,
Ent.NumBlocks);
}
std::unique_ptr<llvm::ProfileSummary> &Summary =
UseCS ? this->CS_Summary : this->Summary;
// initialize InstrProfSummary using the SummaryData from disk.
Summary = std::make_unique<ProfileSummary>(
UseCS ? ProfileSummary::PSK_CSInstr : ProfileSummary::PSK_Instr,
DetailedSummary, SummaryData->get(Summary::TotalBlockCount),
SummaryData->get(Summary::MaxBlockCount),
SummaryData->get(Summary::MaxInternalBlockCount),
SummaryData->get(Summary::MaxFunctionCount),
SummaryData->get(Summary::TotalNumBlocks),
SummaryData->get(Summary::TotalNumFunctions));
return Cur + SummarySize;
} else {
// The older versions do not support a profile summary. This just computes
// an empty summary, which will not result in accurate hot/cold detection.
// We would need to call addRecord for all NamedInstrProfRecords to get the
// correct summary. However, this version is old (prior to early 2016) and
// has not been supporting an accurate summary for several years.
InstrProfSummaryBuilder Builder(ProfileSummaryBuilder::DefaultCutoffs);
Summary = Builder.getSummary();
return Cur;
}
}
Error IndexedInstrProfReader::readHeader() {
using namespace support;
const unsigned char *Start =
(const unsigned char *)DataBuffer->getBufferStart();
const unsigned char *Cur = Start;
if ((const unsigned char *)DataBuffer->getBufferEnd() - Cur < 24)
return error(instrprof_error::truncated);
auto *Header = reinterpret_cast<const IndexedInstrProf::Header *>(Cur);
Cur += sizeof(IndexedInstrProf::Header);
// Check the magic number.
uint64_t Magic = endian::byte_swap<uint64_t, little>(Header->Magic);
if (Magic != IndexedInstrProf::Magic)
return error(instrprof_error::bad_magic);
// Read the version.
uint64_t FormatVersion = endian::byte_swap<uint64_t, little>(Header->Version);
if (GET_VERSION(FormatVersion) >
IndexedInstrProf::ProfVersion::CurrentVersion)
return error(instrprof_error::unsupported_version);
Cur = readSummary((IndexedInstrProf::ProfVersion)FormatVersion, Cur,
/* UseCS */ false);
if (FormatVersion & VARIANT_MASK_CSIR_PROF)
Cur = readSummary((IndexedInstrProf::ProfVersion)FormatVersion, Cur,
/* UseCS */ true);
// Read the hash type and start offset.
IndexedInstrProf::HashT HashType = static_cast<IndexedInstrProf::HashT>(
endian::byte_swap<uint64_t, little>(Header->HashType));
if (HashType > IndexedInstrProf::HashT::Last)
return error(instrprof_error::unsupported_hash_type);
uint64_t HashOffset = endian::byte_swap<uint64_t, little>(Header->HashOffset);
// The rest of the file is an on disk hash table.
auto IndexPtr =
std::make_unique<InstrProfReaderIndex<OnDiskHashTableImplV3>>(
Start + HashOffset, Cur, Start, HashType, FormatVersion);
// Load the remapping table now if requested.
if (RemappingBuffer) {
Remapper = std::make_unique<
InstrProfReaderItaniumRemapper<OnDiskHashTableImplV3>>(
std::move(RemappingBuffer), *IndexPtr);
if (Error E = Remapper->populateRemappings())
return E;
} else {
Remapper = std::make_unique<InstrProfReaderNullRemapper>(*IndexPtr);
}
Index = std::move(IndexPtr);
return success();
}
InstrProfSymtab &IndexedInstrProfReader::getSymtab() {
if (Symtab.get())
return *Symtab.get();
std::unique_ptr<InstrProfSymtab> NewSymtab = std::make_unique<InstrProfSymtab>();
if (Error E = Index->populateSymtab(*NewSymtab.get())) {
consumeError(error(InstrProfError::take(std::move(E))));
}
Symtab = std::move(NewSymtab);
return *Symtab.get();
}
Expected<InstrProfRecord>
IndexedInstrProfReader::getInstrProfRecord(StringRef FuncName,
uint64_t FuncHash) {
ArrayRef<NamedInstrProfRecord> Data;
Error Err = Remapper->getRecords(FuncName, Data);
if (Err)
return std::move(Err);
// Found it. Look for counters with the right hash.
for (unsigned I = 0, E = Data.size(); I < E; ++I) {
// Check for a match and fill the vector if there is one.
if (Data[I].Hash == FuncHash) {
return std::move(Data[I]);
}
}
return error(instrprof_error::hash_mismatch);
}
Error IndexedInstrProfReader::getFunctionCounts(StringRef FuncName,
uint64_t FuncHash,
std::vector<uint64_t> &Counts) {
Expected<InstrProfRecord> Record = getInstrProfRecord(FuncName, FuncHash);
if (Error E = Record.takeError())
return error(std::move(E));
Counts = Record.get().Counts;
return success();
}
Error IndexedInstrProfReader::readNextRecord(NamedInstrProfRecord &Record) {
ArrayRef<NamedInstrProfRecord> Data;
Error E = Index->getRecords(Data);
if (E)
return error(std::move(E));
Record = Data[RecordIndex++];
if (RecordIndex >= Data.size()) {
Index->advanceToNextKey();
RecordIndex = 0;
}
return success();
}
void InstrProfReader::accumulateCounts(CountSumOrPercent &Sum, bool IsCS) {
uint64_t NumFuncs = 0;
for (const auto &Func : *this) {
if (isIRLevelProfile()) {
bool FuncIsCS = NamedInstrProfRecord::hasCSFlagInHash(Func.Hash);
if (FuncIsCS != IsCS)
continue;
}
Func.accumulateCounts(Sum);
++NumFuncs;
}
Sum.NumEntries = NumFuncs;
}
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