[llvm] r246584 - gold-plugin: Implement parallel LTO code generation using llvm::splitCodeGen.
Peter Collingbourne via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 1 13:40:22 PDT 2015
Author: pcc
Date: Tue Sep 1 15:40:22 2015
New Revision: 246584
URL: http://llvm.org/viewvc/llvm-project?rev=246584&view=rev
Log:
gold-plugin: Implement parallel LTO code generation using llvm::splitCodeGen.
Parallelism can be enabled using a new plugin option, jobs=N, where N is
the number of code generation threads.
Differential Revision: http://reviews.llvm.org/D12308
Added:
llvm/trunk/test/tools/gold/X86/parallel.ll
Modified:
llvm/trunk/tools/gold/gold-plugin.cpp
Added: llvm/trunk/test/tools/gold/X86/parallel.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/gold/X86/parallel.ll?rev=246584&view=auto
==============================================================================
--- llvm/trunk/test/tools/gold/X86/parallel.ll (added)
+++ llvm/trunk/test/tools/gold/X86/parallel.ll Tue Sep 1 15:40:22 2015
@@ -0,0 +1,22 @@
+; RUN: llvm-as -o %t.bc %s
+; RUN: %gold -plugin %llvmshlibdir/LLVMgold.so -u foo -u bar -plugin-opt jobs=2 -plugin-opt save-temps -o %t %t.bc
+; RUN: llvm-nm %t.o0 | FileCheck --check-prefix=CHECK0 %s
+; RUN: llvm-nm %t.o1 | FileCheck --check-prefix=CHECK1 %s
+
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK0-NOT: bar
+; CHECK0: T foo
+; CHECK0-NOT: bar
+define void @foo() {
+ call void @bar()
+ ret void
+}
+
+; CHECK1-NOT: foo
+; CHECK1: T bar
+; CHECK1-NOT: foo
+define void @bar() {
+ call void @foo()
+ ret void
+}
Modified: llvm/trunk/tools/gold/gold-plugin.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/gold/gold-plugin.cpp?rev=246584&r1=246583&r2=246584&view=diff
==============================================================================
--- llvm/trunk/tools/gold/gold-plugin.cpp (original)
+++ llvm/trunk/tools/gold/gold-plugin.cpp Tue Sep 1 15:40:22 2015
@@ -20,6 +20,7 @@
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/CommandFlags.h"
+#include "llvm/CodeGen/ParallelCG.h"
#include "llvm/IR/AutoUpgrade.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DiagnosticInfo.h"
@@ -92,6 +93,7 @@ namespace options {
static bool generate_api_file = false;
static OutputType TheOutputType = OT_NORMAL;
static unsigned OptLevel = 2;
+ static unsigned Parallelism = 1;
static std::string obj_path;
static std::string extra_library_path;
static std::string triple;
@@ -127,8 +129,11 @@ namespace options {
TheOutputType = OT_DISABLE;
} else if (opt.size() == 2 && opt[0] == 'O') {
if (opt[1] < '0' || opt[1] > '3')
- report_fatal_error("Optimization level must be between 0 and 3");
+ message(LDPL_FATAL, "Optimization level must be between 0 and 3");
OptLevel = opt[1] - '0';
+ } else if (opt.startswith("jobs=")) {
+ if (StringRef(opt_ + 5).getAsInteger(10, Parallelism))
+ message(LDPL_FATAL, "Invalid parallelism level: %s", opt_ + 5);
} else {
// Save this option to pass to the code generator.
// ParseCommandLineOptions() expects argv[0] to be program name. Lazily
@@ -742,8 +747,8 @@ static void saveBCFile(StringRef Path, M
WriteBitcodeToFile(&M, OS, /* ShouldPreserveUseListOrder */ true);
}
-static void codegen(Module &M) {
- const std::string &TripleStr = M.getTargetTriple();
+static void codegen(std::unique_ptr<Module> M) {
+ const std::string &TripleStr = M->getTargetTriple();
Triple TheTriple(TripleStr);
std::string ErrMsg;
@@ -779,12 +784,10 @@ static void codegen(Module &M) {
TripleStr, options::mcpu, Features.getString(), Options, RelocationModel,
CodeModel::Default, CGOptLevel));
- runLTOPasses(M, *TM);
+ runLTOPasses(*M, *TM);
if (options::TheOutputType == options::OT_SAVE_TEMPS)
- saveBCFile(output_name + ".opt.bc", M);
-
- legacy::PassManager CodeGenPasses;
+ saveBCFile(output_name + ".opt.bc", *M);
SmallString<128> Filename;
if (!options::obj_path.empty())
@@ -792,37 +795,47 @@ static void codegen(Module &M) {
else if (options::TheOutputType == options::OT_SAVE_TEMPS)
Filename = output_name + ".o";
- int FD;
+ std::vector<SmallString<128>> Filenames(options::Parallelism);
bool TempOutFile = Filename.empty();
- if (TempOutFile) {
- std::error_code EC =
- sys::fs::createTemporaryFile("lto-llvm", "o", FD, Filename);
- if (EC)
- message(LDPL_FATAL, "Could not create temporary file: %s",
- EC.message().c_str());
- } else {
- std::error_code EC =
- sys::fs::openFileForWrite(Filename.c_str(), FD, sys::fs::F_None);
- if (EC)
- message(LDPL_FATAL, "Could not open file: %s", EC.message().c_str());
- }
-
{
- raw_fd_ostream OS(FD, true);
+ // Open a file descriptor for each backend thread. This is done in a block
+ // so that the output file descriptors are closed before gold opens them.
+ std::list<llvm::raw_fd_ostream> OSs;
+ std::vector<llvm::raw_pwrite_stream *> OSPtrs(options::Parallelism);
+ for (unsigned I = 0; I != options::Parallelism; ++I) {
+ int FD;
+ if (TempOutFile) {
+ std::error_code EC =
+ sys::fs::createTemporaryFile("lto-llvm", "o", FD, Filenames[I]);
+ if (EC)
+ message(LDPL_FATAL, "Could not create temporary file: %s",
+ EC.message().c_str());
+ } else {
+ Filenames[I] = Filename;
+ if (options::Parallelism != 1)
+ Filenames[I] += utostr(I);
+ std::error_code EC =
+ sys::fs::openFileForWrite(Filenames[I], FD, sys::fs::F_None);
+ if (EC)
+ message(LDPL_FATAL, "Could not open file: %s", EC.message().c_str());
+ }
+ OSs.emplace_back(FD, true);
+ OSPtrs[I] = &OSs.back();
+ }
- if (TM->addPassesToEmitFile(CodeGenPasses, OS,
- TargetMachine::CGFT_ObjectFile))
- message(LDPL_FATAL, "Failed to setup codegen");
- CodeGenPasses.run(M);
+ // Run backend threads.
+ splitCodeGen(std::move(M), OSPtrs, options::mcpu, Features.getString(),
+ Options, RelocationModel, CodeModel::Default, CGOptLevel);
+ }
+
+ for (auto &Filename : Filenames) {
+ if (add_input_file(Filename.c_str()) != LDPS_OK)
+ message(LDPL_FATAL,
+ "Unable to add .o file to the link. File left behind in: %s",
+ Filename.c_str());
+ if (TempOutFile)
+ Cleanup.push_back(Filename.c_str());
}
-
- if (add_input_file(Filename.c_str()) != LDPS_OK)
- message(LDPL_FATAL,
- "Unable to add .o file to the link. File left behind in: %s",
- Filename.c_str());
-
- if (TempOutFile)
- Cleanup.push_back(Filename.c_str());
}
/// gold informs us that all symbols have been read. At this point, we use
@@ -889,7 +902,7 @@ static ld_plugin_status allSymbolsReadHo
return LDPS_OK;
}
- codegen(*L.getModule());
+ codegen(std::move(Combined));
if (!options::extra_library_path.empty() &&
set_extra_library_path(options::extra_library_path.c_str()) != LDPS_OK)
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