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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/ArrayRef.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/SwapByteOrder.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <memory>
#include <string>
#include <system_error>
#include <utility>
#include <vector>
using namespace llvm;
static cl::opt<bool> StaticFuncFullModulePrefix(
"static-func-full-module-prefix", cl::init(true),
cl::desc("Use full module build paths in the profile counter names for "
"static functions."));
// This option is tailored to users that have different top-level directory in
// profile-gen and profile-use compilation. Users need to specific the number
// of levels to strip. A value larger than the number of directories in the
// source file will strip all the directory names and only leave the basename.
//
// Note current ThinLTO module importing for the indirect-calls assumes
// the source directory name not being stripped. A non-zero option value here
// can potentially prevent some inter-module indirect-call-promotions.
static cl::opt<unsigned> StaticFuncStripDirNamePrefix(
"static-func-strip-dirname-prefix", cl::init(0),
cl::desc("Strip specified level of directory name from source path in "
"the profile counter name for static functions."));
static 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)";
case instrprof_error::empty_raw_profile:
return "Empty raw profile file";
case instrprof_error::zlib_unavailable:
return "Profile uses zlib compression but the profile reader was built without zlib support";
}
llvm_unreachable("A value of instrprof_error has no message.");
}
namespace {
// 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 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 {
const char *InstrProfSectNameCommon[] = {
#define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) \
SectNameCommon,
#include "llvm/ProfileData/InstrProfData.inc"
};
const char *InstrProfSectNameCoff[] = {
#define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) \
SectNameCoff,
#include "llvm/ProfileData/InstrProfData.inc"
};
const char *InstrProfSectNamePrefix[] = {
#define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) \
Prefix,
#include "llvm/ProfileData/InstrProfData.inc"
};
} // namespace
namespace llvm {
std::string getInstrProfSectionName(InstrProfSectKind IPSK,
Triple::ObjectFormatType OF,
bool AddSegmentInfo) {
std::string SectName;
if (OF == Triple::MachO && AddSegmentInfo)
SectName = InstrProfSectNamePrefix[IPSK];
if (OF == Triple::COFF)
SectName += InstrProfSectNameCoff[IPSK];
else
SectName += InstrProfSectNameCommon[IPSK];
if (OF == Triple::MachO && IPSK == IPSK_data && AddSegmentInfo)
SectName += ",regular,live_support";
return SectName;
}
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);
}
// Strip NumPrefix level of directory name from PathNameStr. If the number of
// directory separators is less than NumPrefix, strip all the directories and
// leave base file name only.
static StringRef stripDirPrefix(StringRef PathNameStr, uint32_t NumPrefix) {
uint32_t Count = NumPrefix;
uint32_t Pos = 0, LastPos = 0;
for (auto & CI : PathNameStr) {
++Pos;
if (llvm::sys::path::is_separator(CI)) {
LastPos = Pos;
--Count;
}
if (Count == 0)
break;
}
return PathNameStr.substr(LastPos);
}
// 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()));
if (StaticFuncFullModulePrefix && StaticFuncStripDirNamePrefix != 0)
FileName = stripDirPrefix(FileName, StaticFuncStripDirNamePrefix);
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);
}
Error 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);
if (Error E = addFuncName(PGOFuncName))
return E;
MD5FuncMap.emplace_back(Function::getGUID(PGOFuncName), &F);
// In ThinLTO, local function may have been promoted to global and have
// suffix added to the function name. We need to add the stripped function
// name to the symbol table so that we can find a match from profile.
if (InLTO) {
auto pos = PGOFuncName.find('.');
if (pos != std::string::npos) {
const std::string &OtherFuncName = PGOFuncName.substr(0, pos);
if (Error E = addFuncName(OtherFuncName))
return E;
MD5FuncMap.emplace_back(Function::getGUID(OtherFuncName), &F);
}
}
}
finalizeSymtab();
return Error::success();
}
Error collectPGOFuncNameStrings(ArrayRef<std::string> NameStrs,
bool doCompression, std::string &Result) {
assert(!NameStrs.empty() && "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;
Error E = zlib::compress(StringRef(UncompressedNameStrings),
CompressedNameStrings, zlib::BestSizeCompression);
if (E) {
consumeError(std::move(E));
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(ArrayRef<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) {
if (!llvm::zlib::isAvailable())
return make_error<InstrProfError>(instrprof_error::zlib_unavailable);
StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
CompressedSize);
if (Error E =
zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
UncompressedSize)) {
consumeError(std::move(E));
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)
if (Error E = Symtab.addFuncName(Name))
return E;
while (P < EndP && *P == 0)
P++;
}
Symtab.finalizeSymtab();
return Error::success();
}
void InstrProfValueSiteRecord::merge(InstrProfValueSiteRecord &Input,
uint64_t Weight,
function_ref<void(instrprof_error)> Warn) {
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)
Warn(instrprof_error::counter_overflow);
++I;
continue;
}
ValueData.insert(I, *J);
}
}
void InstrProfValueSiteRecord::scale(uint64_t Weight,
function_ref<void(instrprof_error)> Warn) {
for (auto I = ValueData.begin(), IE = ValueData.end(); I != IE; ++I) {
bool Overflowed;
I->Count = SaturatingMultiply(I->Count, Weight, &Overflowed);
if (Overflowed)
Warn(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,
function_ref<void(instrprof_error)> Warn) {
uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
if (ThisNumValueSites != OtherNumValueSites) {
Warn(instrprof_error::value_site_count_mismatch);
return;
}
if (!ThisNumValueSites)
return;
std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
getOrCreateValueSitesForKind(ValueKind);
MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
Src.getValueSitesForKind(ValueKind);
for (uint32_t I = 0; I < ThisNumValueSites; I++)
ThisSiteRecords[I].merge(OtherSiteRecords[I], Weight, Warn);
}
void InstrProfRecord::merge(InstrProfRecord &Other, uint64_t Weight,
function_ref<void(instrprof_error)> Warn) {
// If the number of counters doesn't match we either have bad data
// or a hash collision.
if (Counts.size() != Other.Counts.size()) {
Warn(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)
Warn(instrprof_error::counter_overflow);
}
for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
mergeValueProfData(Kind, Other, Weight, Warn);
}
void InstrProfRecord::scaleValueProfData(
uint32_t ValueKind, uint64_t Weight,
function_ref<void(instrprof_error)> Warn) {
for (auto &R : getValueSitesForKind(ValueKind))
R.scale(Weight, Warn);
}
void InstrProfRecord::scale(uint64_t Weight,
function_ref<void(instrprof_error)> Warn) {
for (auto &Count : this->Counts) {
bool Overflowed;
Count = SaturatingMultiply(Count, Weight, &Overflowed);
if (Overflowed)
Warn(instrprof_error::counter_overflow);
}
for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
scaleValueProfData(Kind, Weight, Warn);
}
// 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 =
getOrCreateValueSitesForKind(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) {
auto Closure = InstrProfRecordClosure;
Closure.Record = &Record;
return getValueProfDataSize(&Closure);
}
// 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() && !TT.isOSBinFormatWasm())
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;
}
// Check if INSTR_PROF_RAW_VERSION_VAR is defined.
bool isIRPGOFlagSet(const Module *M) {
auto IRInstrVar =
M->getNamedGlobal(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
if (!IRInstrVar || IRInstrVar->isDeclaration() ||
IRInstrVar->hasLocalLinkage())
return false;
// Check if the flag is set.
if (!IRInstrVar->hasInitializer())
return false;
const Constant *InitVal = IRInstrVar->getInitializer();
if (!InitVal)
return false;
return (dyn_cast<ConstantInt>(InitVal)->getZExtValue() &
VARIANT_MASK_IR_PROF) != 0;
}
// Check if we can safely rename this Comdat function.
bool canRenameComdatFunc(const Function &F, bool CheckAddressTaken) {
if (F.getName().empty())
return false;
if (!needsComdatForCounter(F, *(F.getParent())))
return false;
// Unsafe to rename the address-taken function (which can be used in
// function comparison).
if (CheckAddressTaken && F.hasAddressTaken())
return false;
// Only safe to do if this function may be discarded if it is not used
// in the compilation unit.
if (!GlobalValue::isDiscardableIfUnused(F.getLinkage()))
return false;
// For AvailableExternallyLinkage functions.
if (!F.hasComdat()) {
assert(F.getLinkage() == GlobalValue::AvailableExternallyLinkage);
return true;
}
return true;
}
// Parse the value profile options.
void getMemOPSizeRangeFromOption(StringRef MemOPSizeRange, int64_t &RangeStart,
int64_t &RangeLast) {
static const int64_t DefaultMemOPSizeRangeStart = 0;
static const int64_t DefaultMemOPSizeRangeLast = 8;
RangeStart = DefaultMemOPSizeRangeStart;
RangeLast = DefaultMemOPSizeRangeLast;
if (!MemOPSizeRange.empty()) {
auto Pos = MemOPSizeRange.find(':');
if (Pos != std::string::npos) {
if (Pos > 0)
MemOPSizeRange.substr(0, Pos).getAsInteger(10, RangeStart);
if (Pos < MemOPSizeRange.size() - 1)
MemOPSizeRange.substr(Pos + 1).getAsInteger(10, RangeLast);
} else
MemOPSizeRange.getAsInteger(10, RangeLast);
}
assert(RangeLast >= RangeStart);
}
} // end namespace llvm
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