diff options
Diffstat (limited to 'llvm/lib/Bitcode/Writer/BitcodeWriter.cpp')
| -rw-r--r-- | llvm/lib/Bitcode/Writer/BitcodeWriter.cpp | 324 |
1 files changed, 303 insertions, 21 deletions
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp index f6455728975..b8a000d3b7b 100644 --- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp +++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp @@ -13,6 +13,7 @@ #include "llvm/Bitcode/ReaderWriter.h" #include "ValueEnumerator.h" +#include "llvm/ADT/STLExtras.h" #include "llvm/ADT/Triple.h" #include "llvm/Bitcode/BitstreamWriter.h" #include "llvm/Bitcode/LLVMBitCodes.h" @@ -23,6 +24,7 @@ #include "llvm/IR/InlineAsm.h" #include "llvm/IR/Instructions.h" #include "llvm/IR/LLVMContext.h" +#include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/Module.h" #include "llvm/IR/Operator.h" #include "llvm/IR/UseListOrder.h" @@ -2187,7 +2189,8 @@ static void WriteValueSymbolTable( const ValueSymbolTable &VST, const ValueEnumerator &VE, BitstreamWriter &Stream, uint64_t VSTOffsetPlaceholder = 0, uint64_t BitcodeStartBit = 0, - DenseMap<const Function *, uint64_t> *FunctionIndex = nullptr) { + DenseMap<const Function *, std::unique_ptr<FunctionInfo>> *FunctionIndex = + nullptr) { if (VST.empty()) { // WriteValueSymbolTableForwardDecl should have returned early as // well. Ensure this handling remains in sync by asserting that @@ -2282,7 +2285,8 @@ static void WriteValueSymbolTable( // Save the word offset of the function (from the start of the // actual bitcode written to the stream). assert(FunctionIndex->count(F) == 1); - uint64_t BitcodeIndex = (*FunctionIndex)[F] - BitcodeStartBit; + uint64_t BitcodeIndex = + (*FunctionIndex)[F]->bitcodeIndex() - BitcodeStartBit; assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned"); NameVals.push_back(BitcodeIndex / 32); @@ -2300,9 +2304,7 @@ static void WriteValueSymbolTable( AbbrevToUse = VST_ENTRY_7_ABBREV; } - for (const char *P = Name.getKeyData(), - *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P) - NameVals.push_back((unsigned char)*P); + for (const auto P : Name.getKey()) NameVals.push_back((unsigned char)P); // Emit the finished record. Stream.EmitRecord(Code, NameVals, AbbrevToUse); @@ -2311,6 +2313,68 @@ static void WriteValueSymbolTable( Stream.ExitBlock(); } +/// Emit function names and summary offsets for the combined index +/// used by ThinLTO. +static void WriteCombinedValueSymbolTable(const FunctionInfoIndex *Index, + BitstreamWriter &Stream) { + Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4); + + // 8-bit fixed-width VST_COMBINED_FNENTRY function strings. + BitCodeAbbrev *Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_FNENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); + unsigned FnEntry8BitAbbrev = Stream.EmitAbbrev(Abbv); + + // 7-bit fixed width VST_COMBINED_FNENTRY function strings. + Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_FNENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); + unsigned FnEntry7BitAbbrev = Stream.EmitAbbrev(Abbv); + + // 6-bit char6 VST_COMBINED_FNENTRY function strings. + Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_FNENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6)); + unsigned FnEntry6BitAbbrev = Stream.EmitAbbrev(Abbv); + + // FIXME: We know if the type names can use 7-bit ascii. + SmallVector<unsigned, 64> NameVals; + + for (const auto &FII : *Index) { + for (const auto &FI : FII.getValue()) { + NameVals.push_back(FI->bitcodeIndex()); + + StringRef FuncName = FII.first(); + + // Figure out the encoding to use for the name. + StringEncoding Bits = getStringEncoding(FuncName.data(), FuncName.size()); + + // VST_COMBINED_FNENTRY: [funcsumoffset, namechar x N] + unsigned AbbrevToUse = FnEntry8BitAbbrev; + if (Bits == SE_Char6) + AbbrevToUse = FnEntry6BitAbbrev; + else if (Bits == SE_Fixed7) + AbbrevToUse = FnEntry7BitAbbrev; + + for (const auto P : FuncName) NameVals.push_back((unsigned char)P); + + // Emit the finished record. + Stream.EmitRecord(bitc::VST_CODE_COMBINED_FNENTRY, NameVals, AbbrevToUse); + NameVals.clear(); + } + } + Stream.ExitBlock(); +} + static void WriteUseList(ValueEnumerator &VE, UseListOrder &&Order, BitstreamWriter &Stream) { assert(Order.Shuffle.size() >= 2 && "Shuffle too small"); @@ -2345,14 +2409,33 @@ static void WriteUseListBlock(const Function *F, ValueEnumerator &VE, Stream.ExitBlock(); } -/// WriteFunction - Emit a function body to the module stream. -static void WriteFunction(const Function &F, ValueEnumerator &VE, - BitstreamWriter &Stream, - DenseMap<const Function *, uint64_t> &FunctionIndex) { +/// \brief Save information for the given function into the function index. +/// +/// At a minimum this saves the bitcode index of the function record that +/// was just written. However, if we are emitting function summary information, +/// for example for ThinLTO, then a \a FunctionSummary object is created +/// to hold the provided summary information. +static void SaveFunctionInfo( + const Function &F, + DenseMap<const Function *, std::unique_ptr<FunctionInfo>> &FunctionIndex, + unsigned NumInsts, uint64_t BitcodeIndex, bool EmitFunctionSummary) { + std::unique_ptr<FunctionSummary> FuncSummary; + if (EmitFunctionSummary) { + FuncSummary = llvm::make_unique<FunctionSummary>(NumInsts); + FuncSummary->setLocalFunction(F.hasLocalLinkage()); + } + FunctionIndex[&F] = + llvm::make_unique<FunctionInfo>(BitcodeIndex, std::move(FuncSummary)); +} + +/// Emit a function body to the module stream. +static void WriteFunction( + const Function &F, ValueEnumerator &VE, BitstreamWriter &Stream, + DenseMap<const Function *, std::unique_ptr<FunctionInfo>> &FunctionIndex, + bool EmitFunctionSummary) { // Save the bitcode index of the start of this function block for recording // in the VST. uint64_t BitcodeIndex = Stream.GetCurrentBitNo(); - FunctionIndex[&F] = BitcodeIndex; Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4); VE.incorporateFunction(F); @@ -2379,6 +2462,7 @@ static void WriteFunction(const Function &F, ValueEnumerator &VE, bool NeedsMetadataAttachment = F.hasMetadata(); DILocation *LastDL = nullptr; + unsigned NumInsts = 0; // Finally, emit all the instructions, in order. for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) @@ -2386,6 +2470,8 @@ static void WriteFunction(const Function &F, ValueEnumerator &VE, I != E; ++I) { WriteInstruction(*I, InstID, VE, Stream, Vals); + if (!isa<DbgInfoIntrinsic>(I)) ++NumInsts; + if (!I->getType()->isVoidTy()) ++InstID; @@ -2422,6 +2508,9 @@ static void WriteFunction(const Function &F, ValueEnumerator &VE, WriteUseListBlock(&F, VE, Stream); VE.purgeFunction(); Stream.ExitBlock(); + + SaveFunctionInfo(F, FunctionIndex, NumInsts, BitcodeIndex, + EmitFunctionSummary); } // Emit blockinfo, which defines the standard abbreviations etc. @@ -2599,10 +2688,155 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) { Stream.ExitBlock(); } +/// Write the module path strings, currently only used when generating +/// a combined index file. +static void WriteModStrings(const FunctionInfoIndex *I, + BitstreamWriter &Stream) { + Stream.EnterSubblock(bitc::MODULE_STRTAB_BLOCK_ID, 3); + + // TODO: See which abbrev sizes we actually need to emit + + // 8-bit fixed-width MST_ENTRY strings. + BitCodeAbbrev *Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); + unsigned Abbrev8Bit = Stream.EmitAbbrev(Abbv); + + // 7-bit fixed width MST_ENTRY strings. + Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); + unsigned Abbrev7Bit = Stream.EmitAbbrev(Abbv); + + // 6-bit char6 MST_ENTRY strings. + Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6)); + unsigned Abbrev6Bit = Stream.EmitAbbrev(Abbv); + + SmallVector<unsigned, 64> NameVals; + for (const StringMapEntry<uint64_t> &MPSE : I->modPathStringEntries()) { + StringEncoding Bits = + getStringEncoding(MPSE.getKey().data(), MPSE.getKey().size()); + unsigned AbbrevToUse = Abbrev8Bit; + if (Bits == SE_Char6) + AbbrevToUse = Abbrev6Bit; + else if (Bits == SE_Fixed7) + AbbrevToUse = Abbrev7Bit; + + NameVals.push_back(MPSE.getValue()); + + for (const auto P : MPSE.getKey()) NameVals.push_back((unsigned char)P); + + // Emit the finished record. + Stream.EmitRecord(bitc::MST_CODE_ENTRY, NameVals, AbbrevToUse); + NameVals.clear(); + } + Stream.ExitBlock(); +} + +// Helper to emit a single function summary record. +static void WritePerModuleFunctionSummaryRecord( + SmallVector<unsigned, 64> &NameVals, FunctionSummary *FS, unsigned ValueID, + unsigned FSAbbrev, BitstreamWriter &Stream) { + assert(FS); + NameVals.push_back(ValueID); + NameVals.push_back(FS->isLocalFunction()); + NameVals.push_back(FS->instCount()); + + // Emit the finished record. + Stream.EmitRecord(bitc::FS_CODE_PERMODULE_ENTRY, NameVals, FSAbbrev); + NameVals.clear(); +} + +/// Emit the per-module function summary section alongside the rest of +/// the module's bitcode. +static void WritePerModuleFunctionSummary( + DenseMap<const Function *, std::unique_ptr<FunctionInfo>> &FunctionIndex, + const Module *M, const ValueEnumerator &VE, BitstreamWriter &Stream) { + Stream.EnterSubblock(bitc::FUNCTION_SUMMARY_BLOCK_ID, 3); + + // Abbrev for FS_CODE_PERMODULE_ENTRY. + BitCodeAbbrev *Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::FS_CODE_PERMODULE_ENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // islocal + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // instcount + unsigned FSAbbrev = Stream.EmitAbbrev(Abbv); + + SmallVector<unsigned, 64> NameVals; + for (auto &I : FunctionIndex) { + // Skip anonymous functions. We will emit a function summary for + // any aliases below. + if (!I.first->hasName()) continue; + + WritePerModuleFunctionSummaryRecord( + NameVals, I.second->functionSummary(), + VE.getValueID(M->getValueSymbolTable().lookup(I.first->getName())), + FSAbbrev, Stream); + } + + for (const GlobalAlias &A : M->aliases()) { + if (!A.getBaseObject()) continue; + const Function *F = dyn_cast<Function>(A.getBaseObject()); + if (!F || F->isDeclaration()) continue; + + assert(FunctionIndex.count(F) == 1); + WritePerModuleFunctionSummaryRecord( + NameVals, FunctionIndex[F]->functionSummary(), + VE.getValueID(M->getValueSymbolTable().lookup(A.getName())), FSAbbrev, + Stream); + } + + Stream.ExitBlock(); +} + +/// Emit the combined function summary section into the combined index +/// file. +static void WriteCombinedFunctionSummary(const FunctionInfoIndex *I, + BitstreamWriter &Stream) { + Stream.EnterSubblock(bitc::FUNCTION_SUMMARY_BLOCK_ID, 3); + + // Abbrev for FS_CODE_COMBINED_ENTRY. + BitCodeAbbrev *Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::FS_CODE_COMBINED_ENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // modid + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // instcount + unsigned FSAbbrev = Stream.EmitAbbrev(Abbv); + + SmallVector<unsigned, 64> NameVals; + for (const auto &FII : *I) { + for (auto &FI : FII.getValue()) { + FunctionSummary *FS = FI->functionSummary(); + assert(FS); + + NameVals.push_back(I->getModuleId(FS->modulePath())); + NameVals.push_back(FS->instCount()); + + // Record the starting offset of this summary entry for use + // in the VST entry. Add the current code size since the + // reader will invoke readRecord after the abbrev id read. + FI->setBitcodeIndex(Stream.GetCurrentBitNo() + Stream.GetAbbrevIDWidth()); + + // Emit the finished record. + Stream.EmitRecord(bitc::FS_CODE_COMBINED_ENTRY, NameVals, FSAbbrev); + NameVals.clear(); + } + } + + Stream.ExitBlock(); +} + /// WriteModule - Emit the specified module to the bitstream. static void WriteModule(const Module *M, BitstreamWriter &Stream, bool ShouldPreserveUseListOrder, - uint64_t BitcodeStartBit) { + uint64_t BitcodeStartBit, bool EmitFunctionSummary) { Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3); SmallVector<unsigned, 1> Vals; @@ -2647,10 +2881,15 @@ static void WriteModule(const Module *M, BitstreamWriter &Stream, WriteOperandBundleTags(M, Stream); // Emit function bodies. - DenseMap<const Function *, uint64_t> FunctionIndex; + DenseMap<const Function *, std::unique_ptr<FunctionInfo>> FunctionIndex; for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) if (!F->isDeclaration()) - WriteFunction(*F, VE, Stream, FunctionIndex); + WriteFunction(*F, VE, Stream, FunctionIndex, EmitFunctionSummary); + + // Need to write after the above call to WriteFunction which populates + // the summary information in the index. + if (EmitFunctionSummary) + WritePerModuleFunctionSummary(FunctionIndex, M, VE, Stream); WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream, VSTOffsetPlaceholder, BitcodeStartBit, &FunctionIndex); @@ -2728,10 +2967,22 @@ static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer, Buffer.push_back(0); } +/// Helper to write the header common to all bitcode files. +static void WriteBitcodeHeader(BitstreamWriter &Stream) { + // Emit the file header. + Stream.Emit((unsigned)'B', 8); + Stream.Emit((unsigned)'C', 8); + Stream.Emit(0x0, 4); + Stream.Emit(0xC, 4); + Stream.Emit(0xE, 4); + Stream.Emit(0xD, 4); +} + /// WriteBitcodeToFile - Write the specified module to the specified output /// stream. void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out, - bool ShouldPreserveUseListOrder) { + bool ShouldPreserveUseListOrder, + bool EmitFunctionSummary) { SmallVector<char, 0> Buffer; Buffer.reserve(256*1024); @@ -2751,15 +3002,11 @@ void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out, uint64_t BitcodeStartBit = Stream.GetCurrentBitNo(); // Emit the file header. - Stream.Emit((unsigned)'B', 8); - Stream.Emit((unsigned)'C', 8); - Stream.Emit(0x0, 4); - Stream.Emit(0xC, 4); - Stream.Emit(0xE, 4); - Stream.Emit(0xD, 4); + WriteBitcodeHeader(Stream); // Emit the module. - WriteModule(M, Stream, ShouldPreserveUseListOrder, BitcodeStartBit); + WriteModule(M, Stream, ShouldPreserveUseListOrder, BitcodeStartBit, + EmitFunctionSummary); } if (TT.isOSDarwin()) @@ -2768,3 +3015,38 @@ void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out, // Write the generated bitstream to "Out". Out.write((char*)&Buffer.front(), Buffer.size()); } + +// Write the specified function summary index to the given raw output stream, +// where it will be written in a new bitcode block. This is used when +// writing the combined index file for ThinLTO. +void llvm::WriteFunctionSummaryToFile(const FunctionInfoIndex *Index, + raw_ostream &Out) { + SmallVector<char, 0> Buffer; + Buffer.reserve(256 * 1024); + + BitstreamWriter Stream(Buffer); + + // Emit the bitcode header. + WriteBitcodeHeader(Stream); + + Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3); + + SmallVector<unsigned, 1> Vals; + unsigned CurVersion = 1; + Vals.push_back(CurVersion); + Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals); + + // Write the module paths in the combined index. + WriteModStrings(Index, Stream); + + // Write the function summary combined index records. + WriteCombinedFunctionSummary(Index, Stream); + + // Need a special VST writer for the combined index (we don't have a + // real VST and real values when this is invoked). + WriteCombinedValueSymbolTable(Index, Stream); + + Stream.ExitBlock(); + + Out.write((char *)&Buffer.front(), Buffer.size()); +} |
