Google Git Google Git
Sign in
llvm/llvm-project/refs/heads/users/void/array-bounds-accessed/./bolt/lib/Profile/BoltAddressTranslation.cpp
blob: 2068c9efbcb44dd319849e60bc720a57de6c564d [file] [edit]
//===- bolt/Profile/BoltAddressTranslation.cpp ----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "bolt/Profile/BoltAddressTranslation.h"
#include "bolt/Core/BinaryFunction.h"
#include "llvm/ADT/APInt.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/LEB128.h"
#define DEBUG_TYPE "bolt-bat"
namespace llvm {
namespace bolt {
const char *BoltAddressTranslation::SECTION_NAME = ".note.bolt_bat";
void BoltAddressTranslation::writeEntriesForBB(
MapTy &Map, const BinaryBasicBlock &BB, uint64_t FuncInputAddress,
uint64_t FuncOutputAddress) const {
const uint64_t BBOutputOffset =
BB.getOutputAddressRange().first - FuncOutputAddress;
const uint32_t BBInputOffset = BB.getInputOffset();
// Every output BB must track back to an input BB for profile collection
// in bolted binaries. If we are missing an offset, it means this block was
// created by a pass. We will skip writing any entries for it, and this means
// any traffic happening in this block will map to the previous block in the
// layout. This covers the case where an input basic block is split into two,
// and the second one lacks any offset.
if (BBInputOffset == BinaryBasicBlock::INVALID_OFFSET)
return;
LLVM_DEBUG(dbgs() << "BB " << BB.getName() << "\n");
LLVM_DEBUG(dbgs() << " Key: " << Twine::utohexstr(BBOutputOffset)
<< " Val: " << Twine::utohexstr(BBInputOffset) << "\n");
// NB: in `writeEntriesForBB` we use the input address because hashes are
// saved early in `saveMetadata` before output addresses are assigned.
const BBHashMapTy &BBHashMap = getBBHashMap(FuncInputAddress);
(void)BBHashMap;
LLVM_DEBUG(
dbgs() << formatv(" Hash: {0:x}\n", BBHashMap.getBBHash(BBInputOffset)));
LLVM_DEBUG(
dbgs() << formatv(" Index: {0}\n", BBHashMap.getBBIndex(BBInputOffset)));
// In case of conflicts (same Key mapping to different Vals), the last
// update takes precedence. Of course it is not ideal to have conflicts and
// those happen when we have an empty BB that either contained only
// NOPs or a jump to the next block (successor). Either way, the successor
// and this deleted block will both share the same output address (the same
// key), and we need to map back. We choose here to privilege the successor by
// allowing it to overwrite the previously inserted key in the map.
Map.emplace(BBOutputOffset, BBInputOffset << 1);
const auto &IOAddressMap =
BB.getFunction()->getBinaryContext().getIOAddressMap();
for (const auto &[InputOffset, Sym] : BB.getLocSyms()) {
const auto InputAddress = BB.getFunction()->getAddress() + InputOffset;
const auto OutputAddress = IOAddressMap.lookup(InputAddress);
assert(OutputAddress && "Unknown instruction address");
const auto OutputOffset = *OutputAddress - FuncOutputAddress;
// Is this the first instruction in the BB? No need to duplicate the entry.
if (OutputOffset == BBOutputOffset)
continue;
LLVM_DEBUG(dbgs() << " Key: " << Twine::utohexstr(OutputOffset) << " Val: "
<< Twine::utohexstr(InputOffset) << " (branch)\n");
Map.emplace(OutputOffset, (InputOffset << 1) | BRANCHENTRY);
}
}
void BoltAddressTranslation::write(const BinaryContext &BC, raw_ostream &OS) {
LLVM_DEBUG(dbgs() << "BOLT-DEBUG: Writing BOLT Address Translation Tables\n");
for (auto &BFI : BC.getBinaryFunctions()) {
const BinaryFunction &Function = BFI.second;
const uint64_t InputAddress = Function.getAddress();
const uint64_t OutputAddress = Function.getOutputAddress();
// We don't need a translation table if the body of the function hasn't
// changed
if (Function.isIgnored() || (!BC.HasRelocations && !Function.isSimple()))
continue;
uint32_t NumSecondaryEntryPoints = 0;
Function.forEachEntryPoint([&](uint64_t Offset, const MCSymbol *) {
if (!Offset)
return true;
++NumSecondaryEntryPoints;
SecondaryEntryPointsMap[OutputAddress].push_back(Offset);
return true;
});
LLVM_DEBUG(dbgs() << "Function name: " << Function.getPrintName() << "\n");
LLVM_DEBUG(dbgs() << " Address reference: 0x"
<< Twine::utohexstr(Function.getOutputAddress()) << "\n");
LLVM_DEBUG(dbgs() << formatv(" Hash: {0:x}\n", getBFHash(InputAddress)));
LLVM_DEBUG(dbgs() << " Secondary Entry Points: " << NumSecondaryEntryPoints
<< '\n');
MapTy Map;
for (const BinaryBasicBlock *const BB :
Function.getLayout().getMainFragment())
writeEntriesForBB(Map, *BB, InputAddress, OutputAddress);
// Add entries for deleted blocks. They are still required for correct BB
// mapping of branches modified by SCTC. By convention, they would have the
// end of the function as output address.
const BBHashMapTy &BBHashMap = getBBHashMap(InputAddress);
if (BBHashMap.size() != Function.size()) {
const uint64_t EndOffset = Function.getOutputSize();
std::unordered_set<uint32_t> MappedInputOffsets;
for (const BinaryBasicBlock &BB : Function)
MappedInputOffsets.emplace(BB.getInputOffset());
for (const auto &[InputOffset, _] : BBHashMap)
if (!llvm::is_contained(MappedInputOffsets, InputOffset))
Map.emplace(EndOffset, InputOffset << 1);
}
Maps.emplace(Function.getOutputAddress(), std::move(Map));
ReverseMap.emplace(OutputAddress, InputAddress);
if (!Function.isSplit())
continue;
// Split maps
LLVM_DEBUG(dbgs() << " Cold part\n");
for (const FunctionFragment &FF :
Function.getLayout().getSplitFragments()) {
// Skip empty fragments to avoid adding zero-address entries to maps.
if (FF.empty())
continue;
ColdPartSource.emplace(FF.getAddress(), Function.getOutputAddress());
Map.clear();
for (const BinaryBasicBlock *const BB : FF)
writeEntriesForBB(Map, *BB, InputAddress, FF.getAddress());
Maps.emplace(FF.getAddress(), std::move(Map));
}
}
// Output addresses are delta-encoded
uint64_t PrevAddress = 0;
writeMaps</*Cold=*/false>(PrevAddress, OS);
writeMaps</*Cold=*/true>(PrevAddress, OS);
BC.outs() << "BOLT-INFO: Wrote " << Maps.size() << " BAT maps\n";
BC.outs() << "BOLT-INFO: Wrote " << FuncHashes.getNumFunctions()
<< " function and " << FuncHashes.getNumBasicBlocks()
<< " basic block hashes\n";
}
APInt BoltAddressTranslation::calculateBranchEntriesBitMask(
MapTy &Map, size_t EqualElems) const {
APInt BitMask(alignTo(EqualElems, 8), 0);
size_t Index = 0;
for (std::pair<const uint32_t, uint32_t> &KeyVal : Map) {
if (Index == EqualElems)
break;
const uint32_t OutputOffset = KeyVal.second;
if (OutputOffset & BRANCHENTRY)
BitMask.setBit(Index);
++Index;
}
return BitMask;
}
size_t BoltAddressTranslation::getNumEqualOffsets(const MapTy &Map,
uint32_t Skew) const {
size_t EqualOffsets = 0;
for (const std::pair<const uint32_t, uint32_t> &KeyVal : Map) {
const uint32_t OutputOffset = KeyVal.first;
const uint32_t InputOffset = KeyVal.second >> 1;
if (OutputOffset == InputOffset - Skew)
++EqualOffsets;
else
break;
}
return EqualOffsets;
}
template <bool Cold>
void BoltAddressTranslation::writeMaps(uint64_t &PrevAddress, raw_ostream &OS) {
const uint32_t NumFuncs =
llvm::count_if(llvm::make_first_range(Maps), [&](const uint64_t Address) {
return Cold == ColdPartSource.count(Address);
});
encodeULEB128(NumFuncs, OS);
LLVM_DEBUG(dbgs() << "Writing " << NumFuncs << (Cold ? " cold" : "")
<< " functions for BAT.\n");
size_t PrevIndex = 0;
for (auto &MapEntry : Maps) {
const uint64_t Address = MapEntry.first;
// Only process cold fragments in cold mode, and vice versa.
if (Cold != ColdPartSource.count(Address))
continue;
// NB: in `writeMaps` we use the input address because hashes are saved
// early in `saveMetadata` before output addresses are assigned.
const uint64_t HotInputAddress =
ReverseMap[Cold ? ColdPartSource[Address] : Address];
MapTy &Map = MapEntry.second;
const uint32_t NumEntries = Map.size();
LLVM_DEBUG(dbgs() << "Writing " << NumEntries << " entries for 0x"
<< Twine::utohexstr(Address) << ".\n");
encodeULEB128(Address - PrevAddress, OS);
PrevAddress = Address;
const uint32_t NumSecondaryEntryPoints =
SecondaryEntryPointsMap.count(Address)
? SecondaryEntryPointsMap[Address].size()
: 0;
uint32_t Skew = 0;
if (Cold) {
auto HotEntryIt = llvm::lower_bound(HotFuncs, ColdPartSource[Address]);
assert(HotEntryIt != HotFuncs.end());
size_t HotIndex = std::distance(HotFuncs.begin(), HotEntryIt);
encodeULEB128(HotIndex - PrevIndex, OS);
PrevIndex = HotIndex;
// Skew of all input offsets for cold fragments is simply the first input
// offset.
Skew = Map.begin()->second >> 1;
encodeULEB128(Skew, OS);
} else {
HotFuncs.push_back(Address);
// Function hash
size_t BFHash = getBFHash(HotInputAddress);
LLVM_DEBUG(dbgs() << "Hash: " << formatv("{0:x}\n", BFHash));
OS.write(reinterpret_cast<char *>(&BFHash), 8);
// Number of basic blocks
size_t NumBasicBlocks = NumBasicBlocksMap[HotInputAddress];
LLVM_DEBUG(dbgs() << "Basic blocks: " << NumBasicBlocks << '\n');
encodeULEB128(NumBasicBlocks, OS);
// Secondary entry points
encodeULEB128(NumSecondaryEntryPoints, OS);
LLVM_DEBUG(dbgs() << "Secondary Entry Points: " << NumSecondaryEntryPoints
<< '\n');
}
encodeULEB128(NumEntries, OS);
// Encode the number of equal offsets (output = input - skew) in the
// beginning of the function. Only encode one offset in these cases.
const size_t EqualElems = getNumEqualOffsets(Map, Skew);
encodeULEB128(EqualElems, OS);
if (EqualElems) {
const size_t BranchEntriesBytes = alignTo(EqualElems, 8) / 8;
APInt BranchEntries = calculateBranchEntriesBitMask(Map, EqualElems);
OS.write(reinterpret_cast<const char *>(BranchEntries.getRawData()),
BranchEntriesBytes);
LLVM_DEBUG({
dbgs() << "BranchEntries: ";
SmallString<8> BitMaskStr;
BranchEntries.toString(BitMaskStr, 2, false);
dbgs() << BitMaskStr << '\n';
});
}
const BBHashMapTy &BBHashMap = getBBHashMap(HotInputAddress);
size_t Index = 0;
uint64_t InOffset = 0;
size_t PrevBBIndex = 0;
// Output and Input addresses and delta-encoded
for (std::pair<const uint32_t, uint32_t> &KeyVal : Map) {
const uint64_t OutputAddress = KeyVal.first + Address;
encodeULEB128(OutputAddress - PrevAddress, OS);
PrevAddress = OutputAddress;
if (Index++ >= EqualElems)
encodeSLEB128(KeyVal.second - InOffset, OS);
InOffset = KeyVal.second; // Keeping InOffset as if BRANCHENTRY is encoded
if ((InOffset & BRANCHENTRY) == 0) {
const bool IsBlock = BBHashMap.isInputBlock(InOffset >> 1);
unsigned BBIndex = IsBlock ? BBHashMap.getBBIndex(InOffset >> 1) : 0;
size_t BBHash = IsBlock ? BBHashMap.getBBHash(InOffset >> 1) : 0;
OS.write(reinterpret_cast<char *>(&BBHash), 8);
// Basic block index in the input binary
encodeULEB128(BBIndex - PrevBBIndex, OS);
PrevBBIndex = BBIndex;
LLVM_DEBUG(dbgs() << formatv("{0:x} -> {1:x} {2:x} {3}\n", KeyVal.first,
InOffset >> 1, BBHash, BBIndex));
}
}
uint32_t PrevOffset = 0;
if (!Cold && NumSecondaryEntryPoints) {
LLVM_DEBUG(dbgs() << "Secondary entry points: ");
// Secondary entry point offsets, delta-encoded
for (uint32_t Offset : SecondaryEntryPointsMap[Address]) {
encodeULEB128(Offset - PrevOffset, OS);
LLVM_DEBUG(dbgs() << formatv("{0:x} ", Offset));
PrevOffset = Offset;
}
LLVM_DEBUG(dbgs() << '\n');
}
}
}
std::error_code BoltAddressTranslation::parse(raw_ostream &OS, StringRef Buf) {
DataExtractor DE = DataExtractor(Buf, true);
uint64_t Offset = 0;
if (Buf.size() < 12)
return make_error_code(llvm::errc::io_error);
const uint32_t NameSz = DE.getU32(&Offset);
const uint32_t DescSz = DE.getU32(&Offset);
const uint32_t Type = DE.getU32(&Offset);
if (Type != BinarySection::NT_BOLT_BAT ||
Buf.size() + Offset < alignTo(NameSz, 4) + DescSz)
return make_error_code(llvm::errc::io_error);
StringRef Name = Buf.slice(Offset, Offset + NameSz);
Offset = alignTo(Offset + NameSz, 4);
if (!Name.starts_with("BOLT"))
return make_error_code(llvm::errc::io_error);
Error Err(Error::success());
uint64_t PrevAddress = 0;
parseMaps</*Cold=*/false>(PrevAddress, DE, Offset, Err);
parseMaps</*Cold=*/true>(PrevAddress, DE, Offset, Err);
OS << "BOLT-INFO: Parsed " << Maps.size() << " BAT entries\n";
return errorToErrorCode(std::move(Err));
}
template <bool Cold>
void BoltAddressTranslation::parseMaps(uint64_t &PrevAddress, DataExtractor &DE,
uint64_t &Offset, Error &Err) {
const uint32_t NumFunctions = DE.getULEB128(&Offset, &Err);
LLVM_DEBUG(dbgs() << "Parsing " << NumFunctions << (Cold ? " cold" : "")
<< " functions\n");
size_t HotIndex = 0;
for (uint32_t I = 0; I < NumFunctions; ++I) {
const uint64_t Address = PrevAddress + DE.getULEB128(&Offset, &Err);
uint64_t HotAddress = Cold ? 0 : Address;
PrevAddress = Address;
uint32_t SecondaryEntryPoints = 0;
uint64_t ColdInputSkew = 0;
if (Cold) {
HotIndex += DE.getULEB128(&Offset, &Err);
HotAddress = HotFuncs[HotIndex];
ColdPartSource.emplace(Address, HotAddress);
ColdInputSkew = DE.getULEB128(&Offset, &Err);
} else {
HotFuncs.push_back(Address);
// Function hash
const size_t FuncHash = DE.getU64(&Offset, &Err);
FuncHashes.addEntry(Address, FuncHash);
LLVM_DEBUG(dbgs() << formatv("{0:x}: hash {1:x}\n", Address, FuncHash));
// Number of basic blocks
const size_t NumBasicBlocks = DE.getULEB128(&Offset, &Err);
NumBasicBlocksMap.emplace(Address, NumBasicBlocks);
LLVM_DEBUG(dbgs() << formatv("{0:x}: #bbs {1}, {2} bytes\n", Address,
NumBasicBlocks,
getULEB128Size(NumBasicBlocks)));
// Secondary entry points
SecondaryEntryPoints = DE.getULEB128(&Offset, &Err);
LLVM_DEBUG(
dbgs() << formatv("{0:x}: secondary entry points {1}, {2} bytes\n",
Address, SecondaryEntryPoints,
getULEB128Size(SecondaryEntryPoints)));
}
const uint32_t NumEntries = DE.getULEB128(&Offset, &Err);
// Equal offsets.
const size_t EqualElems = DE.getULEB128(&Offset, &Err);
APInt BEBitMask;
LLVM_DEBUG(dbgs() << formatv("Equal offsets: {0}, {1} bytes\n", EqualElems,
getULEB128Size(EqualElems)));
if (EqualElems) {
const size_t BranchEntriesBytes = alignTo(EqualElems, 8) / 8;
BEBitMask = APInt(alignTo(EqualElems, 8), 0);
LoadIntFromMemory(
BEBitMask,
reinterpret_cast<const uint8_t *>(
DE.getBytes(&Offset, BranchEntriesBytes, &Err).data()),
BranchEntriesBytes);
LLVM_DEBUG({
dbgs() << "BEBitMask: ";
SmallString<8> BitMaskStr;
BEBitMask.toString(BitMaskStr, 2, false);
dbgs() << BitMaskStr << ", " << BranchEntriesBytes << " bytes\n";
});
}
MapTy Map;
LLVM_DEBUG(dbgs() << "Parsing " << NumEntries << " entries for 0x"
<< Twine::utohexstr(Address) << "\n");
uint64_t InputOffset = 0;
size_t BBIndex = 0;
for (uint32_t J = 0; J < NumEntries; ++J) {
const uint64_t OutputDelta = DE.getULEB128(&Offset, &Err);
const uint64_t OutputAddress = PrevAddress + OutputDelta;
const uint64_t OutputOffset = OutputAddress - Address;
PrevAddress = OutputAddress;
int64_t InputDelta = 0;
if (J < EqualElems) {
InputOffset = ((OutputOffset + ColdInputSkew) << 1) | BEBitMask[J];
} else {
InputDelta = DE.getSLEB128(&Offset, &Err);
InputOffset += InputDelta;
}
Map.insert(std::pair<uint32_t, uint32_t>(OutputOffset, InputOffset));
size_t BBHash = 0;
size_t BBIndexDelta = 0;
const bool IsBranchEntry = InputOffset & BRANCHENTRY;
if (!IsBranchEntry) {
BBHash = DE.getU64(&Offset, &Err);
BBIndexDelta = DE.getULEB128(&Offset, &Err);
BBIndex += BBIndexDelta;
// Map basic block hash to hot fragment by input offset
getBBHashMap(HotAddress).addEntry(InputOffset >> 1, BBIndex, BBHash);
}
LLVM_DEBUG({
dbgs() << formatv(
"{0:x} -> {1:x} ({2}/{3}b -> {4}/{5}b), {6:x}", OutputOffset,
InputOffset, OutputDelta, getULEB128Size(OutputDelta), InputDelta,
(J < EqualElems) ? 0 : getSLEB128Size(InputDelta), OutputAddress);
if (!IsBranchEntry) {
dbgs() << formatv(" {0:x} {1}/{2}b", BBHash, BBIndex,
getULEB128Size(BBIndexDelta));
}
dbgs() << '\n';
});
}
Maps.insert(std::pair<uint64_t, MapTy>(Address, Map));
if (!Cold && SecondaryEntryPoints) {
uint32_t EntryPointOffset = 0;
LLVM_DEBUG(dbgs() << "Secondary entry points: ");
for (uint32_t EntryPointId = 0; EntryPointId != SecondaryEntryPoints;
++EntryPointId) {
uint32_t OffsetDelta = DE.getULEB128(&Offset, &Err);
EntryPointOffset += OffsetDelta;
SecondaryEntryPointsMap[Address].push_back(EntryPointOffset);
LLVM_DEBUG(dbgs() << formatv("{0:x}/{1}b ", EntryPointOffset,
getULEB128Size(OffsetDelta)));
}
LLVM_DEBUG(dbgs() << '\n');
}
}
}
void BoltAddressTranslation::dump(raw_ostream &OS) const {
const size_t NumTables = Maps.size();
OS << "BAT tables for " << NumTables << " functions:\n";
for (const auto &MapEntry : Maps) {
const uint64_t Address = MapEntry.first;
const uint64_t HotAddress = fetchParentAddress(Address);
const bool IsHotFunction = HotAddress == 0;
OS << "Function Address: 0x" << Twine::utohexstr(Address);
if (IsHotFunction)
OS << formatv(", hash: {0:x}", getBFHash(Address));
OS << "\n";
OS << "BB mappings:\n";
const BBHashMapTy &BBHashMap =
getBBHashMap(HotAddress ? HotAddress : Address);
for (const auto &Entry : MapEntry.second) {
const bool IsBranch = Entry.second & BRANCHENTRY;
const uint32_t Val = Entry.second >> 1; // dropping BRANCHENTRY bit
OS << "0x" << Twine::utohexstr(Entry.first) << " -> "
<< "0x" << Twine::utohexstr(Val);
if (IsBranch)
OS << " (branch)";
else
OS << formatv(" hash: {0:x}", BBHashMap.getBBHash(Val));
OS << "\n";
}
if (IsHotFunction) {
auto NumBasicBlocksIt = NumBasicBlocksMap.find(Address);
assert(NumBasicBlocksIt != NumBasicBlocksMap.end());
OS << "NumBlocks: " << NumBasicBlocksIt->second << '\n';
}
auto SecondaryEntryPointsIt = SecondaryEntryPointsMap.find(Address);
if (SecondaryEntryPointsIt != SecondaryEntryPointsMap.end()) {
const std::vector<uint32_t> &SecondaryEntryPoints =
SecondaryEntryPointsIt->second;
OS << SecondaryEntryPoints.size() << " secondary entry points:\n";
for (uint32_t EntryPointOffset : SecondaryEntryPoints)
OS << formatv("{0:x}\n", EntryPointOffset);
}
OS << "\n";
}
const size_t NumColdParts = ColdPartSource.size();
if (!NumColdParts)
return;
OS << NumColdParts << " cold mappings:\n";
for (const auto &Entry : ColdPartSource) {
OS << "0x" << Twine::utohexstr(Entry.first) << " -> "
<< Twine::utohexstr(Entry.second) << "\n";
}
OS << "\n";
}
uint64_t BoltAddressTranslation::translate(uint64_t FuncAddress,
uint64_t Offset,
bool IsBranchSrc) const {
auto Iter = Maps.find(FuncAddress);
if (Iter == Maps.end())
return Offset;
const MapTy &Map = Iter->second;
auto KeyVal = Map.upper_bound(Offset);
if (KeyVal == Map.begin())
return Offset;
--KeyVal;
const uint32_t Val = KeyVal->second >> 1; // dropping BRANCHENTRY bit
// Branch source addresses are translated to the first instruction of the
// source BB to avoid accounting for modifications BOLT may have made in the
// BB regarding deletion/addition of instructions.
if (IsBranchSrc)
return Val;
return Offset - KeyVal->first + Val;
}
std::optional<BoltAddressTranslation::FallthroughListTy>
BoltAddressTranslation::getFallthroughsInTrace(uint64_t FuncAddress,
uint64_t From,
uint64_t To) const {
SmallVector<std::pair<uint64_t, uint64_t>, 16> Res;
// Filter out trivial case
if (From >= To)
return Res;
From -= FuncAddress;
To -= FuncAddress;
auto Iter = Maps.find(FuncAddress);
if (Iter == Maps.end())
return std::nullopt;
const MapTy &Map = Iter->second;
auto FromIter = Map.upper_bound(From);
if (FromIter == Map.begin())
return Res;
// Skip instruction entries, to create fallthroughs we are only interested in
// BB boundaries
do {
if (FromIter == Map.begin())
return Res;
--FromIter;
} while (FromIter->second & BRANCHENTRY);
auto ToIter = Map.upper_bound(To);
if (ToIter == Map.begin())
return Res;
--ToIter;
if (FromIter->first >= ToIter->first)
return Res;
for (auto Iter = FromIter; Iter != ToIter;) {
const uint32_t Src = Iter->second >> 1;
if (Iter->second & BRANCHENTRY) {
++Iter;
continue;
}
++Iter;
while (Iter->second & BRANCHENTRY && Iter != ToIter)
++Iter;
if (Iter->second & BRANCHENTRY)
break;
Res.emplace_back(Src, Iter->second >> 1);
}
return Res;
}
bool BoltAddressTranslation::enabledFor(
llvm::object::ELFObjectFileBase *InputFile) const {
for (const SectionRef &Section : InputFile->sections()) {
Expected<StringRef> SectionNameOrErr = Section.getName();
if (Error E = SectionNameOrErr.takeError())
continue;
if (SectionNameOrErr.get() == SECTION_NAME)
return true;
}
return false;
}
void BoltAddressTranslation::saveMetadata(BinaryContext &BC) {
for (BinaryFunction &BF : llvm::make_second_range(BC.getBinaryFunctions())) {
// We don't need a translation table if the body of the function hasn't
// changed
if (BF.isIgnored() || (!BC.HasRelocations && !BF.isSimple()))
continue;
// Prepare function and block hashes
FuncHashes.addEntry(BF.getAddress(), BF.computeHash());
BF.computeBlockHashes();
BBHashMapTy &BBHashMap = getBBHashMap(BF.getAddress());
// Set BF/BB metadata
for (const BinaryBasicBlock &BB : BF)
BBHashMap.addEntry(BB.getInputOffset(), BB.getIndex(), BB.getHash());
NumBasicBlocksMap.emplace(BF.getAddress(), BF.size());
}
}
unsigned
BoltAddressTranslation::getSecondaryEntryPointId(uint64_t Address,
uint32_t Offset) const {
auto FunctionIt = SecondaryEntryPointsMap.find(Address);
if (FunctionIt == SecondaryEntryPointsMap.end())
return 0;
const std::vector<uint32_t> &Offsets = FunctionIt->second;
auto OffsetIt = llvm::find(Offsets, Offset);
if (OffsetIt == Offsets.end())
return 0;
// Adding one here because main entry point is not stored in BAT, and
// enumeration for secondary entry points starts with 1.
return OffsetIt - Offsets.begin() + 1;
}
std::pair<const BinaryFunction *, unsigned>
BoltAddressTranslation::translateSymbol(const BinaryContext &BC,
const MCSymbol &Symbol,
uint32_t Offset) const {
// The symbol could be a secondary entry in a cold fragment.
uint64_t SymbolValue = cantFail(errorOrToExpected(BC.getSymbolValue(Symbol)));
const BinaryFunction *Callee = BC.getFunctionForSymbol(&Symbol);
assert(Callee);
// Containing function, not necessarily the same as symbol value.
const uint64_t CalleeAddress = Callee->getAddress();
const uint32_t OutputOffset = SymbolValue - CalleeAddress;
const uint64_t ParentAddress = fetchParentAddress(CalleeAddress);
const uint64_t HotAddress = ParentAddress ? ParentAddress : CalleeAddress;
const BinaryFunction *ParentBF = BC.getBinaryFunctionAtAddress(HotAddress);
const uint32_t InputOffset =
translate(CalleeAddress, OutputOffset, /*IsBranchSrc*/ false) + Offset;
unsigned SecondaryEntryId{0};
if (InputOffset)
SecondaryEntryId = getSecondaryEntryPointId(HotAddress, InputOffset);
return std::pair(ParentBF, SecondaryEntryId);
}
} // namespace bolt
} // namespace llvm