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

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//=-- 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/ADT/Triple.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/MDBuilder.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"
#include "llvm/Support/Path.h"
using namespace llvm;
static cl::opt<bool> StaticFuncFullModulePrefix(
"static-func-full-module-prefix", cl::init(false),
cl::desc("Use full module build paths in the profile counter names for "
"static functions."));
namespace {
std::string getInstrProfErrString(instrprof_error Err) {
switch (Err) {
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)";
case instrprof_error::compress_failed:
return "Failed to compress data (zlib)";
case instrprof_error::uncompress_failed:
return "Failed to uncompress data (zlib)";
}
llvm_unreachable("A value of instrprof_error has no message.");
}
// FIXME: This class is only here to support the transition to llvm::Error. It
// will be removed once this transition is complete. Clients should prefer to
// deal with the Error value directly, rather than converting to error_code.
class InstrProfErrorCategoryType : public std::error_category {
const char *name() const LLVM_NOEXCEPT override { return "llvm.instrprof"; }
std::string message(int IE) const override {
return getInstrProfErrString(static_cast<instrprof_error>(IE));
}
};
} // end anonymous namespace
static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
const std::error_category &llvm::instrprof_category() {
return *ErrorCategory;
}
namespace llvm {
void SoftInstrProfErrors::addError(instrprof_error IE) {
if (IE == instrprof_error::success)
return;
if (FirstError == instrprof_error::success)
FirstError = IE;
switch (IE) {
case instrprof_error::hash_mismatch:
++NumHashMismatches;
break;
case instrprof_error::count_mismatch:
++NumCountMismatches;
break;
case instrprof_error::counter_overflow:
++NumCounterOverflows;
break;
case instrprof_error::value_site_count_mismatch:
++NumValueSiteCountMismatches;
break;
default:
llvm_unreachable("Not a soft error");
}
}
std::string InstrProfError::message() const {
return getInstrProfErrString(Err);
}
char InstrProfError::ID = 0;
std::string getPGOFuncName(StringRef RawFuncName,
GlobalValue::LinkageTypes Linkage,
StringRef FileName,
uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
return GlobalValue::getGlobalIdentifier(RawFuncName, Linkage, FileName);
}
// Return the PGOFuncName. This function has some special handling when called
// in LTO optimization. The following only applies when calling in LTO passes
// (when \c InLTO is true): LTO's internalization privatizes many global linkage
// symbols. This happens after value profile annotation, but those internal
// linkage functions should not have a source prefix.
// Additionally, for ThinLTO mode, exported internal functions are promoted
// and renamed. We need to ensure that the original internal PGO name is
// used when computing the GUID that is compared against the profiled GUIDs.
// To differentiate compiler generated internal symbols from original ones,
// PGOFuncName meta data are created and attached to the original internal
// symbols in the value profile annotation step
// (PGOUseFunc::annotateIndirectCallSites). If a symbol does not have the meta
// data, its original linkage must be non-internal.
std::string getPGOFuncName(const Function &F, bool InLTO, uint64_t Version) {
if (!InLTO) {
StringRef FileName = (StaticFuncFullModulePrefix
? F.getParent()->getName()
: sys::path::filename(F.getParent()->getName()));
return getPGOFuncName(F.getName(), F.getLinkage(), FileName, Version);
}
// In LTO mode (when InLTO is true), first check if there is a meta data.
if (MDNode *MD = getPGOFuncNameMetadata(F)) {
StringRef S = cast<MDString>(MD->getOperand(0))->getString();
return S.str();
}
// If there is no meta data, the function must be a global before the value
// profile annotation pass. Its current linkage may be internal if it is
// internalized in LTO mode.
return getPGOFuncName(F.getName(), GlobalValue::ExternalLinkage, "");
}
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.
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 PGOFuncName) {
// 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(), PGOFuncName, false);
auto FuncNameVar =
new GlobalVariable(M, Value->getType(), true, Linkage, Value,
getPGOFuncNameVarName(PGOFuncName, 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 PGOFuncName) {
return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), PGOFuncName);
}
void InstrProfSymtab::create(Module &M, bool InLTO) {
for (Function &F : M) {
// Function may not have a name: like using asm("") to overwrite the name.
// Ignore in this case.
if (!F.hasName())
continue;
const std::string &PGOFuncName = getPGOFuncName(F, InLTO);
addFuncName(PGOFuncName);
MD5FuncMap.emplace_back(Function::getGUID(PGOFuncName), &F);
}
finalizeSymtab();
}
Error collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
bool doCompression, std::string &Result) {
assert(NameStrs.size() && "No name data to emit");
uint8_t Header[16], *P = Header;
std::string UncompressedNameStrings =
join(NameStrs.begin(), NameStrs.end(), getInstrProfNameSeparator());
assert(StringRef(UncompressedNameStrings)
.count(getInstrProfNameSeparator()) == (NameStrs.size() - 1) &&
"PGO name is invalid (contains separator token)");
unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
P += EncLen;
auto WriteStringToResult = [&](size_t CompressedLen, StringRef 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 Error::success();
};
if (!doCompression) {
return WriteStringToResult(0, UncompressedNameStrings);
}
SmallString<128> CompressedNameStrings;
zlib::Status Success =
zlib::compress(StringRef(UncompressedNameStrings), CompressedNameStrings,
zlib::BestSizeCompression);
if (Success != zlib::StatusOK)
return make_error<InstrProfError>(instrprof_error::compress_failed);
return WriteStringToResult(CompressedNameStrings.size(),
CompressedNameStrings);
}
StringRef getPGOFuncNameVarInitializer(GlobalVariable *NameVar) {
auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
StringRef NameStr =
Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
return NameStr;
}
Error collectPGOFuncNameStrings(const std::vector<GlobalVariable *> &NameVars,
std::string &Result, bool doCompression) {
std::vector<std::string> NameStrs;
for (auto *NameVar : NameVars) {
NameStrs.push_back(getPGOFuncNameVarInitializer(NameVar));
}
return collectPGOFuncNameStrings(
NameStrs, zlib::isAvailable() && doCompression, Result);
}
Error 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 make_error<InstrProfError>(instrprof_error::uncompress_failed);
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, getInstrProfNameSeparator());
for (StringRef &Name : Names)
Symtab.addFuncName(Name);
while (P < EndP && *P == 0)
P++;
}
Symtab.finalizeSymtab();
return Error::success();
}
void InstrProfValueSiteRecord::merge(SoftInstrProfErrors &SIPE,
InstrProfValueSiteRecord &Input,
uint64_t Weight) {
this->sortByTargetValues();
Input.sortByTargetValues();
auto I = ValueData.begin();
auto IE = ValueData.end();
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) {
bool Overflowed;
I->Count = SaturatingMultiplyAdd(J->Count, Weight, I->Count, &Overflowed);
if (Overflowed)
SIPE.addError(instrprof_error::counter_overflow);
++I;
continue;
}
ValueData.insert(I, *J);
}
}
void InstrProfValueSiteRecord::scale(SoftInstrProfErrors &SIPE,
uint64_t Weight) {
for (auto I = ValueData.begin(), IE = ValueData.end(); I != IE; ++I) {
bool Overflowed;
I->Count = SaturatingMultiply(I->Count, Weight, &Overflowed);
if (Overflowed)
SIPE.addError(instrprof_error::counter_overflow);
}
}
// Merge Value Profile data from Src record to this record for ValueKind.
// Scale merged value counts by \p Weight.
void InstrProfRecord::mergeValueProfData(uint32_t ValueKind,
InstrProfRecord &Src,
uint64_t Weight) {
uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
if (ThisNumValueSites != OtherNumValueSites) {
SIPE.addError(instrprof_error::value_site_count_mismatch);
return;
}
std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
getValueSitesForKind(ValueKind);
std::vector<InstrProfValueSiteRecord> &OtherSiteRecords =
Src.getValueSitesForKind(ValueKind);
for (uint32_t I = 0; I < ThisNumValueSites; I++)
ThisSiteRecords[I].merge(SIPE, OtherSiteRecords[I], Weight);
}
void 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()) {
SIPE.addError(instrprof_error::count_mismatch);
return;
}
for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
bool Overflowed;
Counts[I] =
SaturatingMultiplyAdd(Other.Counts[I], Weight, Counts[I], &Overflowed);
if (Overflowed)
SIPE.addError(instrprof_error::counter_overflow);
}
for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
mergeValueProfData(Kind, Other, Weight);
}
void InstrProfRecord::scaleValueProfData(uint32_t ValueKind, uint64_t Weight) {
uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
getValueSitesForKind(ValueKind);
for (uint32_t I = 0; I < ThisNumValueSites; I++)
ThisSiteRecords[I].scale(SIPE, Weight);
}
void InstrProfRecord::scale(uint64_t Weight) {
for (auto &Count : this->Counts) {
bool Overflowed;
Count = SaturatingMultiply(Count, Weight, &Overflowed);
if (Overflowed)
SIPE.addError(instrprof_error::counter_overflow);
}
for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
scaleValueProfData(Kind, Weight);
}
// 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; });
// Raw function pointer collected by value profiler may be from
// external functions that are not instrumented. They won't have
// mapping data to be used by the deserializer. Force the value to
// be 0 in this case.
if (Result != ValueMap->end() && Result->first == Value)
Value = (uint64_t)Result->second;
else
Value = 0;
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.emplace_back();
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) {
reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(Dst, K, S);
}
ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
ValueProfData *VD =
(ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
memset(VD, 0, TotalSizeInBytes);
return VD;
}
static ValueProfRecordClosure InstrProfRecordClosure = {
nullptr,
getNumValueKindsInstrProf,
getNumValueSitesInstrProf,
getNumValueDataInstrProf,
getNumValueDataForSiteInstrProf,
nullptr,
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());
}
Error ValueProfData::checkIntegrity() {
if (NumValueKinds > IPVK_Last + 1)
return make_error<InstrProfError>(instrprof_error::malformed);
// Total size needs to be mulltiple of quadword size.
if (TotalSize % sizeof(uint64_t))
return make_error<InstrProfError>(instrprof_error::malformed);
ValueProfRecord *VR = getFirstValueProfRecord(this);
for (uint32_t K = 0; K < this->NumValueKinds; K++) {
if (VR->Kind > IPVK_Last)
return make_error<InstrProfError>(instrprof_error::malformed);
VR = getValueProfRecordNext(VR);
if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
return make_error<InstrProfError>(instrprof_error::malformed);
}
return Error::success();
}
Expected<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 make_error<InstrProfError>(instrprof_error::truncated);
const unsigned char *Header = D;
uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
if (D + TotalSize > BufferEnd)
return make_error<InstrProfError>(instrprof_error::too_large);
std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
memcpy(VPD.get(), D, TotalSize);
// Byte swap.
VPD->swapBytesToHost(Endianness);
Error E = VPD->checkIntegrity();
if (E)
return std::move(E);
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);
}
void annotateValueSite(Module &M, Instruction &Inst,
const InstrProfRecord &InstrProfR,
InstrProfValueKind ValueKind, uint32_t SiteIdx,
uint32_t MaxMDCount) {
uint32_t NV = InstrProfR.getNumValueDataForSite(ValueKind, SiteIdx);
if (!NV)
return;
uint64_t Sum = 0;
std::unique_ptr<InstrProfValueData[]> VD =
InstrProfR.getValueForSite(ValueKind, SiteIdx, &Sum);
ArrayRef<InstrProfValueData> VDs(VD.get(), NV);
annotateValueSite(M, Inst, VDs, Sum, ValueKind, MaxMDCount);
}
void annotateValueSite(Module &M, Instruction &Inst,
ArrayRef<InstrProfValueData> VDs,
uint64_t Sum, InstrProfValueKind ValueKind,
uint32_t MaxMDCount) {
LLVMContext &Ctx = M.getContext();
MDBuilder MDHelper(Ctx);
SmallVector<Metadata *, 3> Vals;
// Tag
Vals.push_back(MDHelper.createString("VP"));
// Value Kind
Vals.push_back(MDHelper.createConstant(
ConstantInt::get(Type::getInt32Ty(Ctx), ValueKind)));
// Total Count
Vals.push_back(
MDHelper.createConstant(ConstantInt::get(Type::getInt64Ty(Ctx), Sum)));
// Value Profile Data
uint32_t MDCount = MaxMDCount;
for (auto &VD : VDs) {
Vals.push_back(MDHelper.createConstant(
ConstantInt::get(Type::getInt64Ty(Ctx), VD.Value)));
Vals.push_back(MDHelper.createConstant(
ConstantInt::get(Type::getInt64Ty(Ctx), VD.Count)));
if (--MDCount == 0)
break;
}
Inst.setMetadata(LLVMContext::MD_prof, MDNode::get(Ctx, Vals));
}
bool getValueProfDataFromInst(const Instruction &Inst,
InstrProfValueKind ValueKind,
uint32_t MaxNumValueData,
InstrProfValueData ValueData[],
uint32_t &ActualNumValueData, uint64_t &TotalC) {
MDNode *MD = Inst.getMetadata(LLVMContext::MD_prof);
if (!MD)
return false;
unsigned NOps = MD->getNumOperands();
if (NOps < 5)
return false;
// Operand 0 is a string tag "VP":
MDString *Tag = cast<MDString>(MD->getOperand(0));
if (!Tag)
return false;
if (!Tag->getString().equals("VP"))
return false;
// Now check kind:
ConstantInt *KindInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
if (!KindInt)
return false;
if (KindInt->getZExtValue() != ValueKind)
return false;
// Get total count
ConstantInt *TotalCInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
if (!TotalCInt)
return false;
TotalC = TotalCInt->getZExtValue();
ActualNumValueData = 0;
for (unsigned I = 3; I < NOps; I += 2) {
if (ActualNumValueData >= MaxNumValueData)
break;
ConstantInt *Value = mdconst::dyn_extract<ConstantInt>(MD->getOperand(I));
ConstantInt *Count =
mdconst::dyn_extract<ConstantInt>(MD->getOperand(I + 1));
if (!Value || !Count)
return false;
ValueData[ActualNumValueData].Value = Value->getZExtValue();
ValueData[ActualNumValueData].Count = Count->getZExtValue();
ActualNumValueData++;
}
return true;
}
MDNode *getPGOFuncNameMetadata(const Function &F) {
return F.getMetadata(getPGOFuncNameMetadataName());
}
void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName) {
// Only for internal linkage functions.
if (PGOFuncName == F.getName())
return;
// Don't create duplicated meta-data.
if (getPGOFuncNameMetadata(F))
return;
LLVMContext &C = F.getContext();
MDNode *N = MDNode::get(C, MDString::get(C, PGOFuncName));
F.setMetadata(getPGOFuncNameMetadataName(), N);
}
bool needsComdatForCounter(const Function &F, const Module &M) {
if (F.hasComdat())
return true;
Triple TT(M.getTargetTriple());
if (!TT.isOSBinFormatELF())
return false;
// See createPGOFuncNameVar for more details. To avoid link errors, profile
// counters for function with available_externally linkage needs to be changed
// to linkonce linkage. On ELF based systems, this leads to weak symbols to be
// created. Without using comdat, duplicate entries won't be removed by the
// linker leading to increased data segement size and raw profile size. Even
// worse, since the referenced counter from profile per-function data object
// will be resolved to the common strong definition, the profile counts for
// available_externally functions will end up being duplicated in raw profile
// data. This can result in distorted profile as the counts of those dups
// will be accumulated by the profile merger.
GlobalValue::LinkageTypes Linkage = F.getLinkage();
if (Linkage != GlobalValue::ExternalWeakLinkage &&
Linkage != GlobalValue::AvailableExternallyLinkage)
return false;
return true;
}
} // end namespace llvm
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