bolt/lib/Profile/BoltAddressTranslation.cpp - llvm-project - Git at Google

 //===- 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/Support/DataExtractor.h"
 #include "llvm/Support/Errc.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 FuncAddress) {
   const uint64_t BBOutputOffset =
       BB.getOutputAddressRange().first - FuncAddress;
   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");
   // 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[BBOutputOffset] = BBInputOffset;

   for (const auto &IOPair : BB.getOffsetTranslationTable()) {
     const uint64_t OutputOffset = IOPair.first + BBOutputOffset;
     const uint32_t InputOffset = IOPair.second;

     // 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.insert(
         std::pair<uint32_t, uint32_t>(OutputOffset, InputOffset | 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;
     // We don't need a translation table if the body of the function hasn't
     // changed
     if (Function.isIgnored() || (!BC.HasRelocations && !Function.isSimple()))
       continue;

     LLVM_DEBUG(dbgs() << "Function name: " << Function.getPrintName() << "\n");
     LLVM_DEBUG(dbgs() << " Address reference: 0x"
                       << Twine::utohexstr(Function.getOutputAddress()) << "\n");

     MapTy Map;
     for (const BinaryBasicBlock *const BB :
          Function.getLayout().getMainFragment())
       writeEntriesForBB(Map, *BB, Function.getOutputAddress());
     Maps.emplace(Function.getOutputAddress(), std::move(Map));

     if (!Function.isSplit())
       continue;

     // Split maps
     LLVM_DEBUG(dbgs() << " Cold part\n");
     for (const FunctionFragment &FF :
          Function.getLayout().getSplitFragments()) {
       Map.clear();
       for (const BinaryBasicBlock *const BB : FF)
         writeEntriesForBB(Map, *BB, FF.getAddress());

       Maps.emplace(FF.getAddress(), std::move(Map));
       ColdPartSource.emplace(FF.getAddress(), Function.getOutputAddress());
     }
   }

   const uint32_t NumFuncs = Maps.size();
   OS.write(reinterpret_cast<const char *>(&NumFuncs), 4);
   LLVM_DEBUG(dbgs() << "Writing " << NumFuncs << " functions for BAT.\n");
   for (auto &MapEntry : Maps) {
     const uint64_t Address = MapEntry.first;
     MapTy &Map = MapEntry.second;
     const uint32_t NumEntries = Map.size();
     LLVM_DEBUG(dbgs() << "Writing " << NumEntries << " entries for 0x"
                       << Twine::utohexstr(Address) << ".\n");
     OS.write(reinterpret_cast<const char *>(&Address), 8);
     OS.write(reinterpret_cast<const char *>(&NumEntries), 4);
     for (std::pair<const uint32_t, uint32_t> &KeyVal : Map) {
       OS.write(reinterpret_cast<const char *>(&KeyVal.first), 4);
       OS.write(reinterpret_cast<const char *>(&KeyVal.second), 4);
     }
   }
   const uint32_t NumColdEntries = ColdPartSource.size();
   LLVM_DEBUG(dbgs() << "Writing " << NumColdEntries
                     << " cold part mappings.\n");
   OS.write(reinterpret_cast<const char *>(&NumColdEntries), 4);
   for (std::pair<const uint64_t, uint64_t> &ColdEntry : ColdPartSource) {
     OS.write(reinterpret_cast<const char *>(&ColdEntry.first), 8);
     OS.write(reinterpret_cast<const char *>(&ColdEntry.second), 8);
     LLVM_DEBUG(dbgs() << " " << Twine::utohexstr(ColdEntry.first) << " -> "
                       << Twine::utohexstr(ColdEntry.second) << "\n");
   }

   outs() << "BOLT-INFO: Wrote " << Maps.size() << " BAT maps\n";
   outs() << "BOLT-INFO: Wrote " << NumColdEntries
          << " BAT cold-to-hot entries\n";
 }

 std::error_code BoltAddressTranslation::parse(StringRef Buf) {
   DataExtractor DE = DataExtractor(Buf, true, 8);
   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.substr(0, 4) != "BOLT")
     return make_error_code(llvm::errc::io_error);

   if (Buf.size() - Offset < 4)
     return make_error_code(llvm::errc::io_error);

   const uint32_t NumFunctions = DE.getU32(&Offset);
   LLVM_DEBUG(dbgs() << "Parsing " << NumFunctions << " functions\n");
   for (uint32_t I = 0; I < NumFunctions; ++I) {
     if (Buf.size() - Offset < 12)
       return make_error_code(llvm::errc::io_error);

     const uint64_t Address = DE.getU64(&Offset);
     const uint32_t NumEntries = DE.getU32(&Offset);
     MapTy Map;

     LLVM_DEBUG(dbgs() << "Parsing " << NumEntries << " entries for 0x"
                       << Twine::utohexstr(Address) << "\n");
     if (Buf.size() - Offset < 8 * NumEntries)
       return make_error_code(llvm::errc::io_error);
     for (uint32_t J = 0; J < NumEntries; ++J) {
       const uint32_t OutputAddr = DE.getU32(&Offset);
       const uint32_t InputAddr = DE.getU32(&Offset);
       Map.insert(std::pair<uint32_t, uint32_t>(OutputAddr, InputAddr));
       LLVM_DEBUG(dbgs() << Twine::utohexstr(OutputAddr) << " -> "
                         << Twine::utohexstr(InputAddr) << "\n");
     }
     Maps.insert(std::pair<uint64_t, MapTy>(Address, Map));
   }

   if (Buf.size() - Offset < 4)
     return make_error_code(llvm::errc::io_error);

   const uint32_t NumColdEntries = DE.getU32(&Offset);
   LLVM_DEBUG(dbgs() << "Parsing " << NumColdEntries << " cold part mappings\n");
   for (uint32_t I = 0; I < NumColdEntries; ++I) {
     if (Buf.size() - Offset < 16)
       return make_error_code(llvm::errc::io_error);
     const uint32_t ColdAddress = DE.getU64(&Offset);
     const uint32_t HotAddress = DE.getU64(&Offset);
     ColdPartSource.insert(
         std::pair<uint64_t, uint64_t>(ColdAddress, HotAddress));
     LLVM_DEBUG(dbgs() << Twine::utohexstr(ColdAddress) << " -> "
                       << Twine::utohexstr(HotAddress) << "\n");
   }
   outs() << "BOLT-INFO: Parsed " << Maps.size() << " BAT entries\n";
   outs() << "BOLT-INFO: Parsed " << NumColdEntries
          << " BAT cold-to-hot entries\n";

   return std::error_code();
 }

 void BoltAddressTranslation::dump(raw_ostream &OS) {
   const size_t NumTables = Maps.size();
   OS << "BAT tables for " << NumTables << " functions:\n";
   for (const auto &MapEntry : Maps) {
     OS << "Function Address: 0x" << Twine::utohexstr(MapEntry.first) << "\n";
     OS << "BB mappings:\n";
     for (const auto &Entry : MapEntry.second) {
       const bool IsBranch = Entry.second & BRANCHENTRY;
       const uint32_t Val = Entry.second & ~BRANCHENTRY;
       OS << "0x" << Twine::utohexstr(Entry.first) << " -> "
          << "0x" << Twine::utohexstr(Val);
       if (IsBranch)
         OS << " (branch)";
       OS << "\n";
     }
     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 & ~BRANCHENTRY;
   // 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->first;
     if (Iter->second & BRANCHENTRY) {
       ++Iter;
       continue;
     }

     ++Iter;
     while (Iter->second & BRANCHENTRY && Iter != ToIter)
       ++Iter;
     if (Iter->second & BRANCHENTRY)
       break;
     Res.emplace_back(Src, Iter->first);
   }

   return Res;
 }

 uint64_t BoltAddressTranslation::fetchParentAddress(uint64_t Address) const {
   auto Iter = ColdPartSource.find(Address);
   if (Iter == ColdPartSource.end())
     return 0;
   return Iter->second;
 }

 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;
 }
 } // namespace bolt
 } // namespace llvm
	//===- 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/Support/DataExtractor.h"
	#include "llvm/Support/Errc.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 FuncAddress) {
	const uint64_t BBOutputOffset =
	BB.getOutputAddressRange().first - FuncAddress;
	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");
	// 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[BBOutputOffset] = BBInputOffset;

	for (const auto &IOPair : BB.getOffsetTranslationTable()) {
	const uint64_t OutputOffset = IOPair.first + BBOutputOffset;
	const uint32_t InputOffset = IOPair.second;

	// 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.insert(
	std::pair<uint32_t, uint32_t>(OutputOffset, InputOffset \| 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;
	// We don't need a translation table if the body of the function hasn't
	// changed
	if (Function.isIgnored() \|\| (!BC.HasRelocations && !Function.isSimple()))
	continue;

	LLVM_DEBUG(dbgs() << "Function name: " << Function.getPrintName() << "\n");
	LLVM_DEBUG(dbgs() << " Address reference: 0x"
	<< Twine::utohexstr(Function.getOutputAddress()) << "\n");

	MapTy Map;
	for (const BinaryBasicBlock *const BB :
	Function.getLayout().getMainFragment())
	writeEntriesForBB(Map, *BB, Function.getOutputAddress());
	Maps.emplace(Function.getOutputAddress(), std::move(Map));

	if (!Function.isSplit())
	continue;

	// Split maps
	LLVM_DEBUG(dbgs() << " Cold part\n");
	for (const FunctionFragment &FF :
	Function.getLayout().getSplitFragments()) {
	Map.clear();
	for (const BinaryBasicBlock *const BB : FF)
	writeEntriesForBB(Map, *BB, FF.getAddress());

	Maps.emplace(FF.getAddress(), std::move(Map));
	ColdPartSource.emplace(FF.getAddress(), Function.getOutputAddress());
	}
	}

	const uint32_t NumFuncs = Maps.size();
	OS.write(reinterpret_cast<const char *>(&NumFuncs), 4);
	LLVM_DEBUG(dbgs() << "Writing " << NumFuncs << " functions for BAT.\n");
	for (auto &MapEntry : Maps) {
	const uint64_t Address = MapEntry.first;
	MapTy &Map = MapEntry.second;
	const uint32_t NumEntries = Map.size();
	LLVM_DEBUG(dbgs() << "Writing " << NumEntries << " entries for 0x"
	<< Twine::utohexstr(Address) << ".\n");
	OS.write(reinterpret_cast<const char *>(&Address), 8);
	OS.write(reinterpret_cast<const char *>(&NumEntries), 4);
	for (std::pair<const uint32_t, uint32_t> &KeyVal : Map) {
	OS.write(reinterpret_cast<const char *>(&KeyVal.first), 4);
	OS.write(reinterpret_cast<const char *>(&KeyVal.second), 4);
	}
	}
	const uint32_t NumColdEntries = ColdPartSource.size();
	LLVM_DEBUG(dbgs() << "Writing " << NumColdEntries
	<< " cold part mappings.\n");
	OS.write(reinterpret_cast<const char *>(&NumColdEntries), 4);
	for (std::pair<const uint64_t, uint64_t> &ColdEntry : ColdPartSource) {
	OS.write(reinterpret_cast<const char *>(&ColdEntry.first), 8);
	OS.write(reinterpret_cast<const char *>(&ColdEntry.second), 8);
	LLVM_DEBUG(dbgs() << " " << Twine::utohexstr(ColdEntry.first) << " -> "
	<< Twine::utohexstr(ColdEntry.second) << "\n");
	}

	outs() << "BOLT-INFO: Wrote " << Maps.size() << " BAT maps\n";
	outs() << "BOLT-INFO: Wrote " << NumColdEntries
	<< " BAT cold-to-hot entries\n";
	}

	std::error_code BoltAddressTranslation::parse(StringRef Buf) {
	DataExtractor DE = DataExtractor(Buf, true, 8);
	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.substr(0, 4) != "BOLT")
	return make_error_code(llvm::errc::io_error);

	if (Buf.size() - Offset < 4)
	return make_error_code(llvm::errc::io_error);

	const uint32_t NumFunctions = DE.getU32(&Offset);
	LLVM_DEBUG(dbgs() << "Parsing " << NumFunctions << " functions\n");
	for (uint32_t I = 0; I < NumFunctions; ++I) {
	if (Buf.size() - Offset < 12)
	return make_error_code(llvm::errc::io_error);

	const uint64_t Address = DE.getU64(&Offset);
	const uint32_t NumEntries = DE.getU32(&Offset);
	MapTy Map;

	LLVM_DEBUG(dbgs() << "Parsing " << NumEntries << " entries for 0x"
	<< Twine::utohexstr(Address) << "\n");
	if (Buf.size() - Offset < 8 * NumEntries)
	return make_error_code(llvm::errc::io_error);
	for (uint32_t J = 0; J < NumEntries; ++J) {
	const uint32_t OutputAddr = DE.getU32(&Offset);
	const uint32_t InputAddr = DE.getU32(&Offset);
	Map.insert(std::pair<uint32_t, uint32_t>(OutputAddr, InputAddr));
	LLVM_DEBUG(dbgs() << Twine::utohexstr(OutputAddr) << " -> "
	<< Twine::utohexstr(InputAddr) << "\n");
	}
	Maps.insert(std::pair<uint64_t, MapTy>(Address, Map));
	}

	if (Buf.size() - Offset < 4)
	return make_error_code(llvm::errc::io_error);

	const uint32_t NumColdEntries = DE.getU32(&Offset);
	LLVM_DEBUG(dbgs() << "Parsing " << NumColdEntries << " cold part mappings\n");
	for (uint32_t I = 0; I < NumColdEntries; ++I) {
	if (Buf.size() - Offset < 16)
	return make_error_code(llvm::errc::io_error);
	const uint32_t ColdAddress = DE.getU64(&Offset);
	const uint32_t HotAddress = DE.getU64(&Offset);
	ColdPartSource.insert(
	std::pair<uint64_t, uint64_t>(ColdAddress, HotAddress));
	LLVM_DEBUG(dbgs() << Twine::utohexstr(ColdAddress) << " -> "
	<< Twine::utohexstr(HotAddress) << "\n");
	}
	outs() << "BOLT-INFO: Parsed " << Maps.size() << " BAT entries\n";
	outs() << "BOLT-INFO: Parsed " << NumColdEntries
	<< " BAT cold-to-hot entries\n";

	return std::error_code();
	}

	void BoltAddressTranslation::dump(raw_ostream &OS) {
	const size_t NumTables = Maps.size();
	OS << "BAT tables for " << NumTables << " functions:\n";
	for (const auto &MapEntry : Maps) {
	OS << "Function Address: 0x" << Twine::utohexstr(MapEntry.first) << "\n";
	OS << "BB mappings:\n";
	for (const auto &Entry : MapEntry.second) {
	const bool IsBranch = Entry.second & BRANCHENTRY;
	const uint32_t Val = Entry.second & ~BRANCHENTRY;
	OS << "0x" << Twine::utohexstr(Entry.first) << " -> "
	<< "0x" << Twine::utohexstr(Val);
	if (IsBranch)
	OS << " (branch)";
	OS << "\n";
	}
	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 & ~BRANCHENTRY;
	// 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->first;
	if (Iter->second & BRANCHENTRY) {
	++Iter;
	continue;
	}

	++Iter;
	while (Iter->second & BRANCHENTRY && Iter != ToIter)
	++Iter;
	if (Iter->second & BRANCHENTRY)
	break;
	Res.emplace_back(Src, Iter->first);
	}

	return Res;
	}

	uint64_t BoltAddressTranslation::fetchParentAddress(uint64_t Address) const {
	auto Iter = ColdPartSource.find(Address);
	if (Iter == ColdPartSource.end())
	return 0;
	return Iter->second;
	}

	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;
	}
	} // namespace bolt
	} // namespace llvm