llvm/tools/llvm-lto/llvm-lto.cpp
Arnold Schwaighofer b26fb77d9b Add an option to the LTO code generator to disable vectorization during LTO
We used to always vectorize (slp and loop vectorize) in the LTO pass pipeline.

r220345 changed it so that we used the PassManager's fields 'LoopVectorize' and
'SLPVectorize' out of the desire to be able to disable vectorization using the
cl::opt flags 'vectorize-loops'/'slp-vectorize' which the before mentioned
fields default to.
Unfortunately, this turns off vectorization because those fields
default to false.
This commit adds flags to the LTO library to disable lto vectorization which
reconciles the desire to optionally disable vectorization during LTO and
the desired behavior of defaulting to enabled vectorization.

We really want tools to set PassManager flags directly to enable/disable
vectorization and not go the route via cl::opt flags *in*
PassManagerBuilder.cpp.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220652 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-26 21:50:58 +00:00

221 lines
6.5 KiB
C++

//===-- llvm-lto: a simple command-line program to link modules with LTO --===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This program takes in a list of bitcode files, links them, performs link-time
// optimization, and outputs an object file.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/StringSet.h"
#include "llvm/CodeGen/CommandFlags.h"
#include "llvm/LTO/LTOCodeGenerator.h"
#include "llvm/LTO/LTOModule.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
static cl::opt<bool>
DisableOpt("disable-opt", cl::init(false),
cl::desc("Do not run any optimization passes"));
static cl::opt<bool>
DisableInline("disable-inlining", cl::init(false),
cl::desc("Do not run the inliner pass"));
static cl::opt<bool>
DisableGVNLoadPRE("disable-gvn-loadpre", cl::init(false),
cl::desc("Do not run the GVN load PRE pass"));
static cl::opt<bool>
DisableLTOVectorization("disable-lto-vectorization", cl::init(false),
cl::desc("Do not run loop or slp vectorization during LTO"));
static cl::opt<bool>
UseDiagnosticHandler("use-diagnostic-handler", cl::init(false),
cl::desc("Use a diagnostic handler to test the handler interface"));
static cl::list<std::string>
InputFilenames(cl::Positional, cl::OneOrMore,
cl::desc("<input bitcode files>"));
static cl::opt<std::string>
OutputFilename("o", cl::init(""),
cl::desc("Override output filename"),
cl::value_desc("filename"));
static cl::list<std::string>
ExportedSymbols("exported-symbol",
cl::desc("Symbol to export from the resulting object file"),
cl::ZeroOrMore);
static cl::list<std::string>
DSOSymbols("dso-symbol",
cl::desc("Symbol to put in the symtab in the resulting dso"),
cl::ZeroOrMore);
namespace {
struct ModuleInfo {
std::vector<bool> CanBeHidden;
};
}
void handleDiagnostics(lto_codegen_diagnostic_severity_t Severity,
const char *Msg, void *) {
switch (Severity) {
case LTO_DS_NOTE:
errs() << "note: ";
break;
case LTO_DS_REMARK:
errs() << "remark: ";
break;
case LTO_DS_ERROR:
errs() << "error: ";
break;
case LTO_DS_WARNING:
errs() << "warning: ";
break;
}
errs() << Msg << "\n";
}
int main(int argc, char **argv) {
// Print a stack trace if we signal out.
sys::PrintStackTraceOnErrorSignal();
PrettyStackTraceProgram X(argc, argv);
llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
cl::ParseCommandLineOptions(argc, argv, "llvm LTO linker\n");
// Initialize the configured targets.
InitializeAllTargets();
InitializeAllTargetMCs();
InitializeAllAsmPrinters();
InitializeAllAsmParsers();
// set up the TargetOptions for the machine
TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
unsigned BaseArg = 0;
LTOCodeGenerator CodeGen;
if (UseDiagnosticHandler)
CodeGen.setDiagnosticHandler(handleDiagnostics, nullptr);
switch (RelocModel) {
case Reloc::Static:
CodeGen.setCodePICModel(LTO_CODEGEN_PIC_MODEL_STATIC);
break;
case Reloc::PIC_:
CodeGen.setCodePICModel(LTO_CODEGEN_PIC_MODEL_DYNAMIC);
break;
case Reloc::DynamicNoPIC:
CodeGen.setCodePICModel(LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC);
break;
default:
CodeGen.setCodePICModel(LTO_CODEGEN_PIC_MODEL_DEFAULT);
}
CodeGen.setDebugInfo(LTO_DEBUG_MODEL_DWARF);
CodeGen.setTargetOptions(Options);
llvm::StringSet<llvm::MallocAllocator> DSOSymbolsSet;
for (unsigned i = 0; i < DSOSymbols.size(); ++i)
DSOSymbolsSet.insert(DSOSymbols[i]);
std::vector<std::string> KeptDSOSyms;
for (unsigned i = BaseArg; i < InputFilenames.size(); ++i) {
std::string error;
std::unique_ptr<LTOModule> Module(
LTOModule::createFromFile(InputFilenames[i].c_str(), Options, error));
if (!error.empty()) {
errs() << argv[0] << ": error loading file '" << InputFilenames[i]
<< "': " << error << "\n";
return 1;
}
if (!CodeGen.addModule(Module.get()))
return 1;
unsigned NumSyms = Module->getSymbolCount();
for (unsigned I = 0; I < NumSyms; ++I) {
StringRef Name = Module->getSymbolName(I);
if (!DSOSymbolsSet.count(Name))
continue;
lto_symbol_attributes Attrs = Module->getSymbolAttributes(I);
unsigned Scope = Attrs & LTO_SYMBOL_SCOPE_MASK;
if (Scope != LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN)
KeptDSOSyms.push_back(Name);
}
}
// Add all the exported symbols to the table of symbols to preserve.
for (unsigned i = 0; i < ExportedSymbols.size(); ++i)
CodeGen.addMustPreserveSymbol(ExportedSymbols[i].c_str());
// Add all the dso symbols to the table of symbols to expose.
for (unsigned i = 0; i < KeptDSOSyms.size(); ++i)
CodeGen.addMustPreserveSymbol(KeptDSOSyms[i].c_str());
std::string attrs;
for (unsigned i = 0; i < MAttrs.size(); ++i) {
if (i > 0)
attrs.append(",");
attrs.append(MAttrs[i]);
}
if (!attrs.empty())
CodeGen.setAttr(attrs.c_str());
if (!OutputFilename.empty()) {
size_t len = 0;
std::string ErrorInfo;
const void *Code =
CodeGen.compile(&len, DisableOpt, DisableInline, DisableGVNLoadPRE,
DisableLTOVectorization, ErrorInfo);
if (!Code) {
errs() << argv[0]
<< ": error compiling the code: " << ErrorInfo << "\n";
return 1;
}
std::error_code EC;
raw_fd_ostream FileStream(OutputFilename, EC, sys::fs::F_None);
if (EC) {
errs() << argv[0] << ": error opening the file '" << OutputFilename
<< "': " << EC.message() << "\n";
return 1;
}
FileStream.write(reinterpret_cast<const char *>(Code), len);
} else {
std::string ErrorInfo;
const char *OutputName = nullptr;
if (!CodeGen.compile_to_file(&OutputName, DisableOpt, DisableInline,
DisableGVNLoadPRE, DisableLTOVectorization,
ErrorInfo)) {
errs() << argv[0]
<< ": error compiling the code: " << ErrorInfo
<< "\n";
return 1;
}
outs() << "Wrote native object file '" << OutputName << "'\n";
}
return 0;
}