1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
|
//===-- 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 {};
}
|
