[lld] r264091 - ELF: Create LTO.{cpp, h} and move LTO-related code to that file.
Rui Ueyama via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 22 13:52:11 PDT 2016
Author: ruiu
Date: Tue Mar 22 15:52:10 2016
New Revision: 264091
URL: http://llvm.org/viewvc/llvm-project?rev=264091&view=rev
Log:
ELF: Create LTO.{cpp,h} and move LTO-related code to that file.
The code for LTO has been growing, so now is probably a good time to
move it to its own file. SymbolTable.cpp is for symbol table, and
because compiling bitcode files are semantically not a part of
symbol table, this is I think a good thing to do.
http://reviews.llvm.org/D18370
Added:
lld/trunk/ELF/LTO.cpp
lld/trunk/ELF/LTO.h
Modified:
lld/trunk/ELF/CMakeLists.txt
lld/trunk/ELF/SymbolTable.cpp
lld/trunk/ELF/SymbolTable.h
Modified: lld/trunk/ELF/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/CMakeLists.txt?rev=264091&r1=264090&r2=264091&view=diff
==============================================================================
--- lld/trunk/ELF/CMakeLists.txt (original)
+++ lld/trunk/ELF/CMakeLists.txt Tue Mar 22 15:52:10 2016
@@ -9,6 +9,7 @@ add_lld_library(lldELF
ICF.cpp
InputFiles.cpp
InputSection.cpp
+ LTO.cpp
LinkerScript.cpp
MarkLive.cpp
OutputSections.cpp
Added: lld/trunk/ELF/LTO.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LTO.cpp?rev=264091&view=auto
==============================================================================
--- lld/trunk/ELF/LTO.cpp (added)
+++ lld/trunk/ELF/LTO.cpp Tue Mar 22 15:52:10 2016
@@ -0,0 +1,140 @@
+//===- LTO.cpp ------------------------------------------------------------===//
+//
+// The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LTO.h"
+#include "Config.h"
+#include "Error.h"
+#include "InputFiles.h"
+#include "Symbols.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/Linker/IRMover.h"
+#include "llvm/Support/StringSaver.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+
+using namespace llvm;
+using namespace llvm::object;
+using namespace llvm::ELF;
+
+using namespace lld;
+using namespace lld::elf;
+
+// This is for use when debugging LTO.
+static void saveLtoObjectFile(StringRef Buffer) {
+ std::error_code EC;
+ raw_fd_ostream OS(Config->OutputFile.str() + ".lto.o", EC,
+ sys::fs::OpenFlags::F_None);
+ check(EC);
+ OS << Buffer;
+}
+
+// This is for use when debugging LTO.
+static void saveBCFile(Module &M, StringRef Suffix) {
+ std::error_code EC;
+ raw_fd_ostream OS(Config->OutputFile.str() + Suffix.str(), EC,
+ sys::fs::OpenFlags::F_None);
+ check(EC);
+ WriteBitcodeToFile(&M, OS, /* ShouldPreserveUseListOrder */ true);
+}
+
+// Run LTO passes.
+// FIXME: Reduce code duplication by sharing this code with the gold plugin.
+static void runLTOPasses(Module &M, TargetMachine &TM) {
+ legacy::PassManager LtoPasses;
+ LtoPasses.add(createTargetTransformInfoWrapperPass(TM.getTargetIRAnalysis()));
+ PassManagerBuilder PMB;
+ PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM.getTargetTriple()));
+ PMB.Inliner = createFunctionInliningPass();
+ PMB.VerifyInput = true;
+ PMB.VerifyOutput = true;
+ PMB.LoopVectorize = true;
+ PMB.SLPVectorize = true;
+ PMB.OptLevel = 2; // FIXME: This should be an option.
+ PMB.populateLTOPassManager(LtoPasses);
+ LtoPasses.run(M);
+
+ if (Config->SaveTemps)
+ saveBCFile(M, ".lto.opt.bc");
+}
+
+void BitcodeCompiler::add(BitcodeFile &F) {
+ std::unique_ptr<IRObjectFile> Obj =
+ check(IRObjectFile::create(F.MB, Context));
+ std::vector<GlobalValue *> Keep;
+ unsigned BodyIndex = 0;
+ ArrayRef<SymbolBody *> Bodies = F.getSymbols();
+
+ for (const BasicSymbolRef &Sym : Obj->symbols()) {
+ GlobalValue *GV = Obj->getSymbolGV(Sym.getRawDataRefImpl());
+ assert(GV);
+ if (GV->hasAppendingLinkage()) {
+ Keep.push_back(GV);
+ continue;
+ }
+ if (!BitcodeFile::shouldSkip(Sym))
+ if (SymbolBody *B = Bodies[BodyIndex++])
+ if (&B->repl() == B && isa<DefinedBitcode>(B))
+ Keep.push_back(GV);
+ }
+
+ Mover.move(Obj->takeModule(), Keep,
+ [](GlobalValue &, IRMover::ValueAdder) {});
+}
+
+// Merge all the bitcode files we have seen, codegen the result
+// and return the resulting ObjectFile.
+template <class ELFT>
+std::unique_ptr<elf::ObjectFile<ELFT>> BitcodeCompiler::compile() {
+ if (Config->SaveTemps)
+ saveBCFile(Combined, ".lto.bc");
+
+ StringRef TripleStr = Combined.getTargetTriple();
+ Triple TheTriple(TripleStr);
+
+ // FIXME: Should we have a default triple? The gold plugin uses
+ // sys::getDefaultTargetTriple(), but that is probably wrong given that this
+ // might be a cross linker.
+
+ std::string ErrMsg;
+ const Target *TheTarget = TargetRegistry::lookupTarget(TripleStr, ErrMsg);
+ if (!TheTarget)
+ fatal("target not found: " + ErrMsg);
+
+ TargetOptions Options;
+ Reloc::Model R = Config->Pic ? Reloc::PIC_ : Reloc::Static;
+ std::unique_ptr<TargetMachine> TM(
+ TheTarget->createTargetMachine(TripleStr, "", "", Options, R));
+
+ runLTOPasses(Combined, *TM);
+
+ raw_svector_ostream OS(OwningData);
+ legacy::PassManager CodeGenPasses;
+ if (TM->addPassesToEmitFile(CodeGenPasses, OS,
+ TargetMachine::CGFT_ObjectFile))
+ fatal("failed to setup codegen");
+ CodeGenPasses.run(Combined);
+ MB = MemoryBuffer::getMemBuffer(OwningData,
+ "LLD-INTERNAL-combined-lto-object", false);
+ if (Config->SaveTemps)
+ saveLtoObjectFile(MB->getBuffer());
+
+ std::unique_ptr<InputFile> IF = createObjectFile(*MB);
+ auto *OF = cast<ObjectFile<ELFT>>(IF.release());
+ return std::unique_ptr<ObjectFile<ELFT>>(OF);
+}
+
+template std::unique_ptr<elf::ObjectFile<ELF32LE>> BitcodeCompiler::compile();
+template std::unique_ptr<elf::ObjectFile<ELF32BE>> BitcodeCompiler::compile();
+template std::unique_ptr<elf::ObjectFile<ELF64LE>> BitcodeCompiler::compile();
+template std::unique_ptr<elf::ObjectFile<ELF64BE>> BitcodeCompiler::compile();
Added: lld/trunk/ELF/LTO.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LTO.h?rev=264091&view=auto
==============================================================================
--- lld/trunk/ELF/LTO.h (added)
+++ lld/trunk/ELF/LTO.h Tue Mar 22 15:52:10 2016
@@ -0,0 +1,51 @@
+//===- LTO.h ----------------------------------------------------*- C++ -*-===//
+//
+// The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides a way to combine bitcode files into one ELF
+// file by compiling them using LLVM.
+//
+// If LTO is in use, your input files are not in regular ELF files
+// but instead LLVM bitcode files. In that case, the linker has to
+// convert bitcode files into the native format so that we can create
+// an ELF file that contains native code. This file provides that
+// functionality.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLD_ELF_LTO_H
+#define LLD_ELF_LTO_H
+
+#include "lld/Core/LLVM.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Linker/IRMover.h"
+
+namespace lld {
+namespace elf {
+
+class BitcodeFile;
+template <class ELFT> class ObjectFile;
+
+class BitcodeCompiler {
+public:
+ void add(BitcodeFile &F);
+ template <class ELFT> std::unique_ptr<ObjectFile<ELFT>> compile();
+
+private:
+ llvm::LLVMContext Context;
+ llvm::Module Combined{"ld-temp.o", Context};
+ llvm::IRMover Mover{Combined};
+ SmallString<0> OwningData;
+ std::unique_ptr<MemoryBuffer> MB;
+};
+}
+}
+
+#endif
Modified: lld/trunk/ELF/SymbolTable.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolTable.cpp?rev=264091&r1=264090&r2=264091&view=diff
==============================================================================
--- lld/trunk/ELF/SymbolTable.cpp (original)
+++ lld/trunk/ELF/SymbolTable.cpp Tue Mar 22 15:52:10 2016
@@ -18,16 +18,8 @@
#include "Config.h"
#include "Error.h"
#include "Symbols.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Bitcode/ReaderWriter.h"
-#include "llvm/IR/LegacyPassManager.h"
-#include "llvm/Linker/IRMover.h"
#include "llvm/Support/StringSaver.h"
-#include "llvm/Support/TargetRegistry.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Transforms/IPO.h"
-#include "llvm/Transforms/IPO/PassManagerBuilder.h"
using namespace llvm;
using namespace llvm::object;
@@ -101,131 +93,17 @@ void SymbolTable<ELFT>::addFile(std::uni
resolve(B);
}
-// This is for use when debugging LTO.
-static void saveLtoObjectFile(StringRef Buffer) {
- std::error_code EC;
- raw_fd_ostream OS(Config->OutputFile.str() + ".lto.o", EC,
- sys::fs::OpenFlags::F_None);
- check(EC);
- OS << Buffer;
-}
-
-// This is for use when debugging LTO.
-static void saveBCFile(Module &M, StringRef Suffix) {
- std::error_code EC;
- raw_fd_ostream OS(Config->OutputFile.str() + Suffix.str(), EC,
- sys::fs::OpenFlags::F_None);
- check(EC);
- WriteBitcodeToFile(&M, OS, /* ShouldPreserveUseListOrder */ true);
-}
-
-static void runLTOPasses(Module &M, TargetMachine &TM) {
- // Run LTO passes.
- // FIXME: Reduce code duplication by sharing this code with the gold plugin.
- legacy::PassManager LtoPasses;
- LtoPasses.add(
- createTargetTransformInfoWrapperPass(TM.getTargetIRAnalysis()));
- PassManagerBuilder PMB;
- PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM.getTargetTriple()));
- PMB.Inliner = createFunctionInliningPass();
- PMB.VerifyInput = true;
- PMB.VerifyOutput = true;
- PMB.LoopVectorize = true;
- PMB.SLPVectorize = true;
- PMB.OptLevel = 2; // FIXME: This should be an option.
- PMB.populateLTOPassManager(LtoPasses);
- LtoPasses.run(M);
-
- if (Config->SaveTemps)
- saveBCFile(M, ".lto.opt.bc");
-}
-
-// Codegen the module M and returns the resulting InputFile.
-template <class ELFT>
-std::unique_ptr<InputFile> SymbolTable<ELFT>::codegen(Module &M) {
- StringRef TripleStr = M.getTargetTriple();
- Triple TheTriple(TripleStr);
-
- // FIXME: Should we have a default triple? The gold plugin uses
- // sys::getDefaultTargetTriple(), but that is probably wrong given that this
- // might be a cross linker.
-
- std::string ErrMsg;
- const Target *TheTarget = TargetRegistry::lookupTarget(TripleStr, ErrMsg);
- if (!TheTarget)
- fatal("target not found: " + ErrMsg);
-
- TargetOptions Options;
- Reloc::Model R = Config->Pic ? Reloc::PIC_ : Reloc::Static;
- std::unique_ptr<TargetMachine> TM(
- TheTarget->createTargetMachine(TripleStr, "", "", Options, R));
-
- runLTOPasses(M, *TM);
-
- raw_svector_ostream OS(OwningLTOData);
- legacy::PassManager CodeGenPasses;
- if (TM->addPassesToEmitFile(CodeGenPasses, OS,
- TargetMachine::CGFT_ObjectFile))
- fatal("failed to setup codegen");
- CodeGenPasses.run(M);
- LtoBuffer = MemoryBuffer::getMemBuffer(
- OwningLTOData, "LLD-INTERNAL-combined-lto-object", false);
- if (Config->SaveTemps)
- saveLtoObjectFile(LtoBuffer->getBuffer());
- return createObjectFile(*LtoBuffer);
-}
-
-static void addBitcodeFile(IRMover &Mover, BitcodeFile &F,
- LLVMContext &Context) {
-
- std::unique_ptr<IRObjectFile> Obj =
- check(IRObjectFile::create(F.MB, Context));
- std::vector<GlobalValue *> Keep;
- unsigned BodyIndex = 0;
- ArrayRef<SymbolBody *> Bodies = F.getSymbols();
-
- for (const BasicSymbolRef &Sym : Obj->symbols()) {
- GlobalValue *GV = Obj->getSymbolGV(Sym.getRawDataRefImpl());
- assert(GV);
- if (GV->hasAppendingLinkage()) {
- Keep.push_back(GV);
- continue;
- }
- if (BitcodeFile::shouldSkip(Sym))
- continue;
- SymbolBody *B = Bodies[BodyIndex++];
- if (!B || &B->repl() != B)
- continue;
- auto *DB = dyn_cast<DefinedBitcode>(B);
- if (!DB)
- continue;
- Keep.push_back(GV);
- }
-
- Mover.move(Obj->takeModule(), Keep,
- [](GlobalValue &, IRMover::ValueAdder) {});
-}
-
-// Merge all the bitcode files we have seen, codegen the result and return
-// the resulting ObjectFile.
-template <class ELFT>
-elf::ObjectFile<ELFT> *SymbolTable<ELFT>::createCombinedLtoObject() {
- LLVMContext Context;
- Module Combined("ld-temp.o", Context);
- IRMover Mover(Combined);
- for (const std::unique_ptr<BitcodeFile> &F : BitcodeFiles)
- addBitcodeFile(Mover, *F, Context);
- if (Config->SaveTemps)
- saveBCFile(Combined, ".lto.bc");
- std::unique_ptr<InputFile> F = codegen(Combined);
- ObjectFiles.emplace_back(cast<ObjectFile<ELFT>>(F.release()));
- return &*ObjectFiles.back();
-}
-
template <class ELFT> void SymbolTable<ELFT>::addCombinedLtoObject() {
if (BitcodeFiles.empty())
return;
- ObjectFile<ELFT> *Obj = createCombinedLtoObject();
+
+ // Compile bitcode files.
+ Lto.reset(new BitcodeCompiler);
+ for (const std::unique_ptr<BitcodeFile> &F : BitcodeFiles)
+ Lto->add(*F);
+ std::unique_ptr<ObjectFile<ELFT>> Obj = Lto->compile<ELFT>();
+
+ // Replace bitcode symbols.
llvm::DenseSet<StringRef> DummyGroups;
Obj->parse(DummyGroups);
for (SymbolBody *Body : Obj->getNonLocalSymbols()) {
@@ -234,6 +112,7 @@ template <class ELFT> void SymbolTable<E
continue;
Sym->Body = Body;
}
+ ObjectFiles.push_back(std::move(Obj));
}
// Add an undefined symbol.
Modified: lld/trunk/ELF/SymbolTable.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolTable.h?rev=264091&r1=264090&r2=264091&view=diff
==============================================================================
--- lld/trunk/ELF/SymbolTable.h (original)
+++ lld/trunk/ELF/SymbolTable.h Tue Mar 22 15:52:10 2016
@@ -11,6 +11,7 @@
#define LLD_ELF_SYMBOL_TABLE_H
#include "InputFiles.h"
+#include "LTO.h"
#include "llvm/ADT/MapVector.h"
namespace llvm {
@@ -74,8 +75,6 @@ private:
std::unique_ptr<InputFile> codegen(llvm::Module &M);
std::string conflictMsg(SymbolBody *Old, SymbolBody *New);
- SmallString<0> OwningLTOData;
- std::unique_ptr<MemoryBuffer> LtoBuffer;
ObjectFile<ELFT> *createCombinedLtoObject();
// The order the global symbols are in is not defined. We can use an arbitrary
@@ -101,6 +100,8 @@ private:
// Set of .so files to not link the same shared object file more than once.
llvm::DenseSet<StringRef> SoNames;
+
+ std::unique_ptr<BitcodeCompiler> Lto;
};
} // namespace elf
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