Stream.EmitRecord(bitc::MODULE_CODE_VERSION, ArrayRef<uint64_t>{2});
}
-/// Class to manage the bitcode writing for a module.
-class ModuleBitcodeWriter : public BitcodeWriterBase {
- /// Pointer to the buffer allocated by caller for bitcode writing.
- const SmallVectorImpl<char> &Buffer;
-
+/// Base class to manage the module bitcode writing, currently subclassed for
+/// ModuleBitcodeWriter and ThinLinkBitcodeWriter.
+class ModuleBitcodeWriterBase : public BitcodeWriterBase {
+protected:
/// The Module to write to bitcode.
const Module &M;
/// Optional per-module index to write for ThinLTO.
const ModuleSummaryIndex *Index;
- /// True if a module hash record should be written.
- bool GenerateHash;
-
- SHA1 Hasher;
-
- /// If non-null, when GenerateHash is true, the resulting hash is written
- /// into ModHash. When GenerateHash is false, that specified value
- /// is used as the hash instead of computing from the generated bitcode.
- /// Can be used to produce the same module hash for a minimized bitcode
- /// used just for the thin link as in the regular full bitcode that will
- /// be used in the backend.
- ModuleHash *ModHash;
-
- /// The start bit of the identification block.
- uint64_t BitcodeStartBit;
-
/// Map that holds the correspondence between GUIDs in the summary index,
/// that came from indirect call profiles, and a value id generated by this
/// class to use in the VST and summary block records.
uint64_t VSTOffsetPlaceholder = 0;
public:
- /// Constructs a ModuleBitcodeWriter object for the given Module,
+ /// Constructs a ModuleBitcodeWriterBase object for the given Module,
/// writing to the provided \p Buffer.
- ModuleBitcodeWriter(const Module *M, SmallVectorImpl<char> &Buffer,
- StringTableBuilder &StrtabBuilder,
- BitstreamWriter &Stream, bool ShouldPreserveUseListOrder,
- const ModuleSummaryIndex *Index, bool GenerateHash,
- ModuleHash *ModHash = nullptr)
- : BitcodeWriterBase(Stream, StrtabBuilder), Buffer(Buffer), M(*M),
- VE(*M, ShouldPreserveUseListOrder), Index(Index),
- GenerateHash(GenerateHash), ModHash(ModHash),
- BitcodeStartBit(Stream.GetCurrentBitNo()) {
+ ModuleBitcodeWriterBase(const Module *M, StringTableBuilder &StrtabBuilder,
+ BitstreamWriter &Stream,
+ bool ShouldPreserveUseListOrder,
+ const ModuleSummaryIndex *Index)
+ : BitcodeWriterBase(Stream, StrtabBuilder), M(*M),
+ VE(*M, ShouldPreserveUseListOrder), Index(Index) {
// Assign ValueIds to any callee values in the index that came from
// indirect call profiles and were recorded as a GUID not a Value*
// (which would have been assigned an ID by the ValueEnumerator).
assignValueId(CallEdge.first.getGUID());
}
+protected:
+ void writePerModuleGlobalValueSummary();
+
+private:
+ void writePerModuleFunctionSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
+ GlobalValueSummary *Summary,
+ unsigned ValueID,
+ unsigned FSCallsAbbrev,
+ unsigned FSCallsProfileAbbrev,
+ const Function &F);
+ void writeModuleLevelReferences(const GlobalVariable &V,
+ SmallVector<uint64_t, 64> &NameVals,
+ unsigned FSModRefsAbbrev);
+
+ void assignValueId(GlobalValue::GUID ValGUID) {
+ GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
+ }
+ unsigned getValueId(GlobalValue::GUID ValGUID) {
+ const auto &VMI = GUIDToValueIdMap.find(ValGUID);
+ // Expect that any GUID value had a value Id assigned by an
+ // earlier call to assignValueId.
+ assert(VMI != GUIDToValueIdMap.end() &&
+ "GUID does not have assigned value Id");
+ return VMI->second;
+ }
+ // Helper to get the valueId for the type of value recorded in VI.
+ unsigned getValueId(ValueInfo VI) {
+ if (!VI.getValue())
+ return getValueId(VI.getGUID());
+ return VE.getValueID(VI.getValue());
+ }
+ std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
+};
+
+/// Class to manage the bitcode writing for a module.
+class ModuleBitcodeWriter : public ModuleBitcodeWriterBase {
+ /// Pointer to the buffer allocated by caller for bitcode writing.
+ const SmallVectorImpl<char> &Buffer;
+
+ /// True if a module hash record should be written.
+ bool GenerateHash;
+
+ /// If non-null, when GenerateHash is true, the resulting hash is written
+ /// into ModHash.
+ ModuleHash *ModHash;
+
+ SHA1 Hasher;
+
+ /// The start bit of the identification block.
+ uint64_t BitcodeStartBit;
+
+public:
+ /// Constructs a ModuleBitcodeWriter object for the given Module,
+ /// writing to the provided \p Buffer.
+ ModuleBitcodeWriter(const Module *M, SmallVectorImpl<char> &Buffer,
+ StringTableBuilder &StrtabBuilder,
+ BitstreamWriter &Stream, bool ShouldPreserveUseListOrder,
+ const ModuleSummaryIndex *Index, bool GenerateHash,
+ ModuleHash *ModHash = nullptr)
+ : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
+ ShouldPreserveUseListOrder, Index),
+ Buffer(Buffer), GenerateHash(GenerateHash), ModHash(ModHash),
+ BitcodeStartBit(Stream.GetCurrentBitNo()) {}
+
/// Emit the current module to the bitstream.
void write();
writeFunction(const Function &F,
DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
void writeBlockInfo();
- void writePerModuleFunctionSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
- GlobalValueSummary *Summary,
- unsigned ValueID,
- unsigned FSCallsAbbrev,
- unsigned FSCallsProfileAbbrev,
- const Function &F);
- void writeModuleLevelReferences(const GlobalVariable &V,
- SmallVector<uint64_t, 64> &NameVals,
- unsigned FSModRefsAbbrev);
- void writePerModuleGlobalValueSummary();
void writeModuleHash(size_t BlockStartPos);
- void assignValueId(GlobalValue::GUID ValGUID) {
- GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
- }
- unsigned getValueId(GlobalValue::GUID ValGUID) {
- const auto &VMI = GUIDToValueIdMap.find(ValGUID);
- // Expect that any GUID value had a value Id assigned by an
- // earlier call to assignValueId.
- assert(VMI != GUIDToValueIdMap.end() &&
- "GUID does not have assigned value Id");
- return VMI->second;
- }
- // Helper to get the valueId for the type of value recorded in VI.
- unsigned getValueId(ValueInfo VI) {
- if (!VI.getValue())
- return getValueId(VI.getGUID());
- return VE.getValueID(VI.getValue());
- }
- std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
-
unsigned getEncodedSyncScopeID(SyncScope::ID SSID) {
return unsigned(SSID);
}
}
// Helper to emit a single function summary record.
-void ModuleBitcodeWriter::writePerModuleFunctionSummaryRecord(
+void ModuleBitcodeWriterBase::writePerModuleFunctionSummaryRecord(
SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
unsigned ValueID, unsigned FSCallsAbbrev, unsigned FSCallsProfileAbbrev,
const Function &F) {
// Collect the global value references in the given variable's initializer,
// and emit them in a summary record.
-void ModuleBitcodeWriter::writeModuleLevelReferences(
+void ModuleBitcodeWriterBase::writeModuleLevelReferences(
const GlobalVariable &V, SmallVector<uint64_t, 64> &NameVals,
unsigned FSModRefsAbbrev) {
auto VI = Index->getValueInfo(GlobalValue::getGUID(V.getName()));
/// Emit the per-module summary section alongside the rest of
/// the module's bitcode.
-void ModuleBitcodeWriter::writePerModuleGlobalValueSummary() {
+void ModuleBitcodeWriterBase::writePerModuleGlobalValueSummary() {
// By default we compile with ThinLTO if the module has a summary, but the
// client can request full LTO with a module flag.
bool IsThinLTO = true;
if (ModHash)
// Save the written hash value.
std::copy(std::begin(Vals), std::end(Vals), std::begin(*ModHash));
- } else if (ModHash)
- Stream.EmitRecord(bitc::MODULE_CODE_HASH, ArrayRef<uint32_t>(*ModHash));
+ }
}
void ModuleBitcodeWriter::write() {
Out.write((char *)&Buffer.front(), Buffer.size());
}
+
+/// Class to manage the bitcode writing for a thin link bitcode file.
+class ThinLinkBitcodeWriter : public ModuleBitcodeWriterBase {
+ /// ModHash is for use in ThinLTO incremental build, generated while writing
+ /// the module bitcode file.
+ const ModuleHash *ModHash;
+
+public:
+ ThinLinkBitcodeWriter(const Module *M, StringTableBuilder &StrtabBuilder,
+ BitstreamWriter &Stream,
+ const ModuleSummaryIndex &Index,
+ const ModuleHash &ModHash)
+ : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
+ /*ShouldPreserveUseListOrder=*/false, &Index),
+ ModHash(&ModHash) {}
+
+ void write();
+
+private:
+ void writeSimplifiedModuleInfo();
+};
+
+// This function writes a simpilified module info for thin link bitcode file.
+// It only contains the source file name along with the name(the offset and
+// size in strtab) and linkage for global values. For the global value info
+// entry, in order to keep linkage at offset 5, there are three zeros used
+// as padding.
+void ThinLinkBitcodeWriter::writeSimplifiedModuleInfo() {
+ SmallVector<unsigned, 64> Vals;
+ // Emit the module's source file name.
+ {
+ StringEncoding Bits = getStringEncoding(M.getSourceFileName());
+ BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
+ if (Bits == SE_Char6)
+ AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
+ else if (Bits == SE_Fixed7)
+ AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
+
+ // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
+ auto Abbv = std::make_shared<BitCodeAbbrev>();
+ Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
+ Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+ Abbv->Add(AbbrevOpToUse);
+ unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
+
+ for (const auto P : M.getSourceFileName())
+ Vals.push_back((unsigned char)P);
+
+ Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
+ Vals.clear();
+ }
+
+ // Emit the global variable information.
+ for (const GlobalVariable &GV : M.globals()) {
+ // GLOBALVAR: [strtab offset, strtab size, 0, 0, 0, linkage]
+ Vals.push_back(StrtabBuilder.add(GV.getName()));
+ Vals.push_back(GV.getName().size());
+ Vals.push_back(0);
+ Vals.push_back(0);
+ Vals.push_back(0);
+ Vals.push_back(getEncodedLinkage(GV));
+
+ Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals);
+ Vals.clear();
+ }
+
+ // Emit the function proto information.
+ for (const Function &F : M) {
+ // FUNCTION: [strtab offset, strtab size, 0, 0, 0, linkage]
+ Vals.push_back(StrtabBuilder.add(F.getName()));
+ Vals.push_back(F.getName().size());
+ Vals.push_back(0);
+ Vals.push_back(0);
+ Vals.push_back(0);
+ Vals.push_back(getEncodedLinkage(F));
+
+ Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals);
+ Vals.clear();
+ }
+
+ // Emit the alias information.
+ for (const GlobalAlias &A : M.aliases()) {
+ // ALIAS: [strtab offset, strtab size, 0, 0, 0, linkage]
+ Vals.push_back(StrtabBuilder.add(A.getName()));
+ Vals.push_back(A.getName().size());
+ Vals.push_back(0);
+ Vals.push_back(0);
+ Vals.push_back(0);
+ Vals.push_back(getEncodedLinkage(A));
+
+ Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals);
+ Vals.clear();
+ }
+
+ // Emit the ifunc information.
+ for (const GlobalIFunc &I : M.ifuncs()) {
+ // IFUNC: [strtab offset, strtab size, 0, 0, 0, linkage]
+ Vals.push_back(StrtabBuilder.add(I.getName()));
+ Vals.push_back(I.getName().size());
+ Vals.push_back(0);
+ Vals.push_back(0);
+ Vals.push_back(0);
+ Vals.push_back(getEncodedLinkage(I));
+
+ Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
+ Vals.clear();
+ }
+}
+
+void ThinLinkBitcodeWriter::write() {
+ Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
+
+ writeModuleVersion();
+
+ writeSimplifiedModuleInfo();
+
+ writePerModuleGlobalValueSummary();
+
+ // Write module hash.
+ Stream.EmitRecord(bitc::MODULE_CODE_HASH, ArrayRef<uint32_t>(*ModHash));
+
+ Stream.ExitBlock();
+}
+
+void BitcodeWriter::writeThinLinkBitcode(const Module *M,
+ const ModuleSummaryIndex &Index,
+ const ModuleHash &ModHash) {
+ assert(!WroteStrtab);
+
+ // The Mods vector is used by irsymtab::build, which requires non-const
+ // Modules in case it needs to materialize metadata. But the bitcode writer
+ // requires that the module is materialized, so we can cast to non-const here,
+ // after checking that it is in fact materialized.
+ assert(M->isMaterialized());
+ Mods.push_back(const_cast<Module *>(M));
+
+ ThinLinkBitcodeWriter ThinLinkWriter(M, StrtabBuilder, *Stream, Index,
+ ModHash);
+ ThinLinkWriter.write();
+}
+
+// Write the specified thin link bitcode file to the given raw output stream,
+// where it will be written in a new bitcode block. This is used when
+// writing the per-module index file for ThinLTO.
+void llvm::WriteThinLinkBitcodeToFile(const Module *M, raw_ostream &Out,
+ const ModuleSummaryIndex &Index,
+ const ModuleHash &ModHash) {
+ SmallVector<char, 0> Buffer;
+ Buffer.reserve(256 * 1024);
+
+ BitcodeWriter Writer(Buffer);
+ Writer.writeThinLinkBitcode(M, Index, ModHash);
+ Writer.writeSymtab();
+ Writer.writeStrtab();
+
+ Out.write((char *)&Buffer.front(), Buffer.size());
+}
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