97 lines
3.8 KiB
C++
97 lines
3.8 KiB
C++
//===-- ParallelCG.cpp ----------------------------------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines functions that can be used for parallel code generation.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/CodeGen/ParallelCG.h"
|
|
#include "llvm/Bitcode/ReaderWriter.h"
|
|
#include "llvm/IR/LLVMContext.h"
|
|
#include "llvm/IR/LegacyPassManager.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/Support/ErrorOr.h"
|
|
#include "llvm/Support/MemoryBuffer.h"
|
|
#include "llvm/Support/TargetRegistry.h"
|
|
#include "llvm/Support/thread.h"
|
|
#include "llvm/Target/TargetMachine.h"
|
|
#include "llvm/Transforms/Utils/SplitModule.h"
|
|
|
|
using namespace llvm;
|
|
|
|
static void codegen(Module *M, llvm::raw_pwrite_stream &OS,
|
|
const Target *TheTarget, StringRef CPU, StringRef Features,
|
|
const TargetOptions &Options, Reloc::Model RM,
|
|
CodeModel::Model CM, CodeGenOpt::Level OL,
|
|
TargetMachine::CodeGenFileType FileType) {
|
|
std::unique_ptr<TargetMachine> TM(TheTarget->createTargetMachine(
|
|
M->getTargetTriple(), CPU, Features, Options, RM, CM, OL));
|
|
|
|
legacy::PassManager CodeGenPasses;
|
|
if (TM->addPassesToEmitFile(CodeGenPasses, OS, FileType))
|
|
report_fatal_error("Failed to setup codegen");
|
|
CodeGenPasses.run(*M);
|
|
}
|
|
|
|
std::unique_ptr<Module>
|
|
llvm::splitCodeGen(std::unique_ptr<Module> M,
|
|
ArrayRef<llvm::raw_pwrite_stream *> OSs, StringRef CPU,
|
|
StringRef Features, const TargetOptions &Options,
|
|
Reloc::Model RM, CodeModel::Model CM, CodeGenOpt::Level OL,
|
|
TargetMachine::CodeGenFileType FileType) {
|
|
StringRef TripleStr = M->getTargetTriple();
|
|
std::string ErrMsg;
|
|
const Target *TheTarget = TargetRegistry::lookupTarget(TripleStr, ErrMsg);
|
|
if (!TheTarget)
|
|
report_fatal_error(Twine("Target not found: ") + ErrMsg);
|
|
|
|
if (OSs.size() == 1) {
|
|
codegen(M.get(), *OSs[0], TheTarget, CPU, Features, Options, RM, CM,
|
|
OL, FileType);
|
|
return M;
|
|
}
|
|
|
|
std::vector<thread> Threads;
|
|
SplitModule(std::move(M), OSs.size(), [&](std::unique_ptr<Module> MPart) {
|
|
// We want to clone the module in a new context to multi-thread the codegen.
|
|
// We do it by serializing partition modules to bitcode (while still on the
|
|
// main thread, in order to avoid data races) and spinning up new threads
|
|
// which deserialize the partitions into separate contexts.
|
|
// FIXME: Provide a more direct way to do this in LLVM.
|
|
SmallVector<char, 0> BC;
|
|
raw_svector_ostream BCOS(BC);
|
|
WriteBitcodeToFile(MPart.get(), BCOS);
|
|
|
|
llvm::raw_pwrite_stream *ThreadOS = OSs[Threads.size()];
|
|
Threads.emplace_back(
|
|
[TheTarget, CPU, Features, Options, RM, CM, OL, FileType,
|
|
ThreadOS](const SmallVector<char, 0> &BC) {
|
|
LLVMContext Ctx;
|
|
ErrorOr<std::unique_ptr<Module>> MOrErr =
|
|
parseBitcodeFile(MemoryBufferRef(StringRef(BC.data(), BC.size()),
|
|
"<split-module>"),
|
|
Ctx);
|
|
if (!MOrErr)
|
|
report_fatal_error("Failed to read bitcode");
|
|
std::unique_ptr<Module> MPartInCtx = std::move(MOrErr.get());
|
|
|
|
codegen(MPartInCtx.get(), *ThreadOS, TheTarget, CPU, Features,
|
|
Options, RM, CM, OL, FileType);
|
|
},
|
|
// Pass BC using std::move to ensure that it get moved rather than
|
|
// copied into the thread's context.
|
|
std::move(BC));
|
|
});
|
|
|
|
for (thread &T : Threads)
|
|
T.join();
|
|
|
|
return {};
|
|
}
|