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

579 lines
20 KiB
C++

//=-- InstrProf.cpp - Instrumented profiling format support -----------------=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains support for clang's instrumentation based PGO and
// coverage.
//
//===----------------------------------------------------------------------===//
#include "llvm/ProfileData/InstrProf.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/ManagedStatic.h"
using namespace llvm;
namespace {
class InstrProfErrorCategoryType : public std::error_category {
const char *name() const LLVM_NOEXCEPT override { return "llvm.instrprof"; }
std::string message(int IE) const override {
instrprof_error E = static_cast<instrprof_error>(IE);
switch (E) {
case instrprof_error::success:
return "Success";
case instrprof_error::eof:
return "End of File";
case instrprof_error::unrecognized_format:
return "Unrecognized instrumentation profile encoding format";
case instrprof_error::bad_magic:
return "Invalid instrumentation profile data (bad magic)";
case instrprof_error::bad_header:
return "Invalid instrumentation profile data (file header is corrupt)";
case instrprof_error::unsupported_version:
return "Unsupported instrumentation profile format version";
case instrprof_error::unsupported_hash_type:
return "Unsupported instrumentation profile hash type";
case instrprof_error::too_large:
return "Too much profile data";
case instrprof_error::truncated:
return "Truncated profile data";
case instrprof_error::malformed:
return "Malformed instrumentation profile data";
case instrprof_error::unknown_function:
return "No profile data available for function";
case instrprof_error::hash_mismatch:
return "Function control flow change detected (hash mismatch)";
case instrprof_error::count_mismatch:
return "Function basic block count change detected (counter mismatch)";
case instrprof_error::counter_overflow:
return "Counter overflow";
case instrprof_error::value_site_count_mismatch:
return "Function value site count change detected (counter mismatch)";
}
llvm_unreachable("A value of instrprof_error has no message.");
}
};
}
static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
const std::error_category &llvm::instrprof_category() {
return *ErrorCategory;
}
namespace llvm {
std::string getPGOFuncName(StringRef RawFuncName,
GlobalValue::LinkageTypes Linkage,
StringRef FileName,
uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
// Function names may be prefixed with a binary '1' to indicate
// that the backend should not modify the symbols due to any platform
// naming convention. Do not include that '1' in the PGO profile name.
if (RawFuncName[0] == '\1')
RawFuncName = RawFuncName.substr(1);
std::string FuncName = RawFuncName;
if (llvm::GlobalValue::isLocalLinkage(Linkage)) {
// For local symbols, prepend the main file name to distinguish them.
// Do not include the full path in the file name since there's no guarantee
// that it will stay the same, e.g., if the files are checked out from
// version control in different locations.
if (FileName.empty())
FuncName = FuncName.insert(0, "<unknown>:");
else
FuncName = FuncName.insert(0, FileName.str() + ":");
}
return FuncName;
}
std::string getPGOFuncName(const Function &F, uint64_t Version) {
return getPGOFuncName(F.getName(), F.getLinkage(), F.getParent()->getName(),
Version);
}
StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName, StringRef FileName) {
if (FileName.empty())
return PGOFuncName;
// Drop the file name including ':'. See also getPGOFuncName.
if (PGOFuncName.startswith(FileName))
PGOFuncName = PGOFuncName.drop_front(FileName.size() + 1);
return PGOFuncName;
}
// \p FuncName is the string used as profile lookup key for the function. A
// symbol is created to hold the name. Return the legalized symbol name.
static std::string getPGOFuncNameVarName(StringRef FuncName,
GlobalValue::LinkageTypes Linkage) {
std::string VarName = getInstrProfNameVarPrefix();
VarName += FuncName;
if (!GlobalValue::isLocalLinkage(Linkage))
return VarName;
// Now fix up illegal chars in local VarName that may upset the assembler.
const char *InvalidChars = "-:<>\"'";
size_t found = VarName.find_first_of(InvalidChars);
while (found != std::string::npos) {
VarName[found] = '_';
found = VarName.find_first_of(InvalidChars, found + 1);
}
return VarName;
}
GlobalVariable *createPGOFuncNameVar(Module &M,
GlobalValue::LinkageTypes Linkage,
StringRef FuncName) {
// We generally want to match the function's linkage, but available_externally
// and extern_weak both have the wrong semantics, and anything that doesn't
// need to link across compilation units doesn't need to be visible at all.
if (Linkage == GlobalValue::ExternalWeakLinkage)
Linkage = GlobalValue::LinkOnceAnyLinkage;
else if (Linkage == GlobalValue::AvailableExternallyLinkage)
Linkage = GlobalValue::LinkOnceODRLinkage;
else if (Linkage == GlobalValue::InternalLinkage ||
Linkage == GlobalValue::ExternalLinkage)
Linkage = GlobalValue::PrivateLinkage;
auto *Value = ConstantDataArray::getString(M.getContext(), FuncName, false);
auto FuncNameVar =
new GlobalVariable(M, Value->getType(), true, Linkage, Value,
getPGOFuncNameVarName(FuncName, Linkage));
// Hide the symbol so that we correctly get a copy for each executable.
if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
return FuncNameVar;
}
GlobalVariable *createPGOFuncNameVar(Function &F, StringRef FuncName) {
return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), FuncName);
}
int collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
bool doCompression, std::string &Result) {
uint8_t Header[16], *P = Header;
std::string UncompressedNameStrings =
join(NameStrs.begin(), NameStrs.end(), StringRef(" "));
unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
P += EncLen;
auto WriteStringToResult = [&](size_t CompressedLen,
const std::string &InputStr) {
EncLen = encodeULEB128(CompressedLen, P);
P += EncLen;
char *HeaderStr = reinterpret_cast<char *>(&Header[0]);
unsigned HeaderLen = P - &Header[0];
Result.append(HeaderStr, HeaderLen);
Result += InputStr;
return 0;
};
if (!doCompression)
return WriteStringToResult(0, UncompressedNameStrings);
SmallVector<char, 128> CompressedNameStrings;
zlib::Status Success =
zlib::compress(StringRef(UncompressedNameStrings), CompressedNameStrings,
zlib::BestSizeCompression);
if (Success != zlib::StatusOK)
return 1;
return WriteStringToResult(
CompressedNameStrings.size(),
std::string(CompressedNameStrings.data(), CompressedNameStrings.size()));
}
StringRef getPGOFuncNameInitializer(GlobalVariable *NameVar) {
auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
StringRef NameStr =
Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
return NameStr;
}
int collectPGOFuncNameStrings(const std::vector<GlobalVariable *> &NameVars,
std::string &Result) {
std::vector<std::string> NameStrs;
for (auto *NameVar : NameVars) {
NameStrs.push_back(getPGOFuncNameInitializer(NameVar));
}
return collectPGOFuncNameStrings(NameStrs, zlib::isAvailable(), Result);
}
int readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
const uint8_t *P = reinterpret_cast<const uint8_t *>(NameStrings.data());
const uint8_t *EndP = reinterpret_cast<const uint8_t *>(NameStrings.data() +
NameStrings.size());
while (P < EndP) {
uint32_t N;
uint64_t UncompressedSize = decodeULEB128(P, &N);
P += N;
uint64_t CompressedSize = decodeULEB128(P, &N);
P += N;
bool isCompressed = (CompressedSize != 0);
SmallString<128> UncompressedNameStrings;
StringRef NameStrings;
if (isCompressed) {
StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
CompressedSize);
if (zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
UncompressedSize) != zlib::StatusOK)
return 1;
P += CompressedSize;
NameStrings = StringRef(UncompressedNameStrings.data(),
UncompressedNameStrings.size());
} else {
NameStrings =
StringRef(reinterpret_cast<const char *>(P), UncompressedSize);
P += UncompressedSize;
}
// Now parse the name strings.
SmallVector<StringRef, 0> Names;
NameStrings.split(Names, ' ');
for (StringRef &Name : Names)
Symtab.addFuncName(Name);
while (P < EndP && *P == 0)
P++;
}
Symtab.finalizeSymtab();
return 0;
}
instrprof_error
InstrProfValueSiteRecord::mergeValueData(InstrProfValueSiteRecord &Input,
uint64_t Weight) {
this->sortByTargetValues();
Input.sortByTargetValues();
auto I = ValueData.begin();
auto IE = ValueData.end();
instrprof_error Result = instrprof_error::success;
for (auto J = Input.ValueData.begin(), JE = Input.ValueData.end(); J != JE;
++J) {
while (I != IE && I->Value < J->Value)
++I;
if (I != IE && I->Value == J->Value) {
uint64_t JCount = J->Count;
bool Overflowed;
if (Weight > 1) {
JCount = SaturatingMultiply(JCount, Weight, &Overflowed);
if (Overflowed)
Result = instrprof_error::counter_overflow;
}
I->Count = SaturatingAdd(I->Count, JCount, &Overflowed);
if (Overflowed)
Result = instrprof_error::counter_overflow;
++I;
continue;
}
ValueData.insert(I, *J);
}
return Result;
}
// Merge Value Profile data from Src record to this record for ValueKind.
// Scale merged value counts by \p Weight.
instrprof_error InstrProfRecord::mergeValueProfData(uint32_t ValueKind,
InstrProfRecord &Src,
uint64_t Weight) {
uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
if (ThisNumValueSites != OtherNumValueSites)
return instrprof_error::value_site_count_mismatch;
std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
getValueSitesForKind(ValueKind);
std::vector<InstrProfValueSiteRecord> &OtherSiteRecords =
Src.getValueSitesForKind(ValueKind);
instrprof_error Result = instrprof_error::success;
for (uint32_t I = 0; I < ThisNumValueSites; I++)
MergeResult(Result,
ThisSiteRecords[I].mergeValueData(OtherSiteRecords[I], Weight));
return Result;
}
instrprof_error InstrProfRecord::merge(InstrProfRecord &Other,
uint64_t Weight) {
// If the number of counters doesn't match we either have bad data
// or a hash collision.
if (Counts.size() != Other.Counts.size())
return instrprof_error::count_mismatch;
instrprof_error Result = instrprof_error::success;
for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
bool Overflowed;
uint64_t OtherCount = Other.Counts[I];
if (Weight > 1) {
OtherCount = SaturatingMultiply(OtherCount, Weight, &Overflowed);
if (Overflowed)
Result = instrprof_error::counter_overflow;
}
Counts[I] = SaturatingAdd(Counts[I], OtherCount, &Overflowed);
if (Overflowed)
Result = instrprof_error::counter_overflow;
}
for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
MergeResult(Result, mergeValueProfData(Kind, Other, Weight));
return Result;
}
// Map indirect call target name hash to name string.
uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
ValueMapType *ValueMap) {
if (!ValueMap)
return Value;
switch (ValueKind) {
case IPVK_IndirectCallTarget: {
auto Result =
std::lower_bound(ValueMap->begin(), ValueMap->end(), Value,
[](const std::pair<uint64_t, uint64_t> &LHS,
uint64_t RHS) { return LHS.first < RHS; });
if (Result != ValueMap->end())
Value = (uint64_t)Result->second;
break;
}
}
return Value;
}
void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
InstrProfValueData *VData, uint32_t N,
ValueMapType *ValueMap) {
for (uint32_t I = 0; I < N; I++) {
VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
}
std::vector<InstrProfValueSiteRecord> &ValueSites =
getValueSitesForKind(ValueKind);
if (N == 0)
ValueSites.push_back(InstrProfValueSiteRecord());
else
ValueSites.emplace_back(VData, VData + N);
}
#define INSTR_PROF_COMMON_API_IMPL
#include "llvm/ProfileData/InstrProfData.inc"
/*!
* \brief ValueProfRecordClosure Interface implementation for InstrProfRecord
* class. These C wrappers are used as adaptors so that C++ code can be
* invoked as callbacks.
*/
uint32_t getNumValueKindsInstrProf(const void *Record) {
return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
}
uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
return reinterpret_cast<const InstrProfRecord *>(Record)
->getNumValueSites(VKind);
}
uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
return reinterpret_cast<const InstrProfRecord *>(Record)
->getNumValueData(VKind);
}
uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
uint32_t S) {
return reinterpret_cast<const InstrProfRecord *>(R)
->getNumValueDataForSite(VK, S);
}
void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
uint32_t K, uint32_t S,
uint64_t (*Mapper)(uint32_t, uint64_t)) {
return reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(
Dst, K, S, Mapper);
}
ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
ValueProfData *VD =
(ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
memset(VD, 0, TotalSizeInBytes);
return VD;
}
static ValueProfRecordClosure InstrProfRecordClosure = {
0,
getNumValueKindsInstrProf,
getNumValueSitesInstrProf,
getNumValueDataInstrProf,
getNumValueDataForSiteInstrProf,
0,
getValueForSiteInstrProf,
allocValueProfDataInstrProf};
// Wrapper implementation using the closure mechanism.
uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
InstrProfRecordClosure.Record = &Record;
return getValueProfDataSize(&InstrProfRecordClosure);
}
// Wrapper implementation using the closure mechanism.
std::unique_ptr<ValueProfData>
ValueProfData::serializeFrom(const InstrProfRecord &Record) {
InstrProfRecordClosure.Record = &Record;
std::unique_ptr<ValueProfData> VPD(
serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
return VPD;
}
void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
InstrProfRecord::ValueMapType *VMap) {
Record.reserveSites(Kind, NumValueSites);
InstrProfValueData *ValueData = getValueProfRecordValueData(this);
for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
uint8_t ValueDataCount = this->SiteCountArray[VSite];
Record.addValueData(Kind, VSite, ValueData, ValueDataCount, VMap);
ValueData += ValueDataCount;
}
}
// For writing/serializing, Old is the host endianness, and New is
// byte order intended on disk. For Reading/deserialization, Old
// is the on-disk source endianness, and New is the host endianness.
void ValueProfRecord::swapBytes(support::endianness Old,
support::endianness New) {
using namespace support;
if (Old == New)
return;
if (getHostEndianness() != Old) {
sys::swapByteOrder<uint32_t>(NumValueSites);
sys::swapByteOrder<uint32_t>(Kind);
}
uint32_t ND = getValueProfRecordNumValueData(this);
InstrProfValueData *VD = getValueProfRecordValueData(this);
// No need to swap byte array: SiteCountArrray.
for (uint32_t I = 0; I < ND; I++) {
sys::swapByteOrder<uint64_t>(VD[I].Value);
sys::swapByteOrder<uint64_t>(VD[I].Count);
}
if (getHostEndianness() == Old) {
sys::swapByteOrder<uint32_t>(NumValueSites);
sys::swapByteOrder<uint32_t>(Kind);
}
}
void ValueProfData::deserializeTo(InstrProfRecord &Record,
InstrProfRecord::ValueMapType *VMap) {
if (NumValueKinds == 0)
return;
ValueProfRecord *VR = getFirstValueProfRecord(this);
for (uint32_t K = 0; K < NumValueKinds; K++) {
VR->deserializeTo(Record, VMap);
VR = getValueProfRecordNext(VR);
}
}
template <class T>
static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
using namespace support;
if (Orig == little)
return endian::readNext<T, little, unaligned>(D);
else
return endian::readNext<T, big, unaligned>(D);
}
static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
ValueProfData());
}
instrprof_error ValueProfData::checkIntegrity() {
if (NumValueKinds > IPVK_Last + 1)
return instrprof_error::malformed;
// Total size needs to be mulltiple of quadword size.
if (TotalSize % sizeof(uint64_t))
return instrprof_error::malformed;
ValueProfRecord *VR = getFirstValueProfRecord(this);
for (uint32_t K = 0; K < this->NumValueKinds; K++) {
if (VR->Kind > IPVK_Last)
return instrprof_error::malformed;
VR = getValueProfRecordNext(VR);
if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
return instrprof_error::malformed;
}
return instrprof_error::success;
}
ErrorOr<std::unique_ptr<ValueProfData>>
ValueProfData::getValueProfData(const unsigned char *D,
const unsigned char *const BufferEnd,
support::endianness Endianness) {
using namespace support;
if (D + sizeof(ValueProfData) > BufferEnd)
return instrprof_error::truncated;
const unsigned char *Header = D;
uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
if (D + TotalSize > BufferEnd)
return instrprof_error::too_large;
std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
memcpy(VPD.get(), D, TotalSize);
// Byte swap.
VPD->swapBytesToHost(Endianness);
instrprof_error EC = VPD->checkIntegrity();
if (EC != instrprof_error::success)
return EC;
return std::move(VPD);
}
void ValueProfData::swapBytesToHost(support::endianness Endianness) {
using namespace support;
if (Endianness == getHostEndianness())
return;
sys::swapByteOrder<uint32_t>(TotalSize);
sys::swapByteOrder<uint32_t>(NumValueKinds);
ValueProfRecord *VR = getFirstValueProfRecord(this);
for (uint32_t K = 0; K < NumValueKinds; K++) {
VR->swapBytes(Endianness, getHostEndianness());
VR = getValueProfRecordNext(VR);
}
}
void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
using namespace support;
if (Endianness == getHostEndianness())
return;
ValueProfRecord *VR = getFirstValueProfRecord(this);
for (uint32_t K = 0; K < NumValueKinds; K++) {
ValueProfRecord *NVR = getValueProfRecordNext(VR);
VR->swapBytes(getHostEndianness(), Endianness);
VR = NVR;
}
sys::swapByteOrder<uint32_t>(TotalSize);
sys::swapByteOrder<uint32_t>(NumValueKinds);
}
}