llvm/tools/llc/llc.cpp
Evan Cheng b95fc31aa2 Sink codegen optimization level into MCCodeGenInfo along side relocation model
and code model. This eliminates the need to pass OptLevel flag all over the
place and makes it possible for any codegen pass to use this information.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144788 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-16 08:38:26 +00:00

388 lines
12 KiB
C++

//===-- llc.cpp - Implement the LLVM Native Code Generator ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This is the llc code generator driver. It provides a convenient
// command-line interface for generating native assembly-language code
// or C code, given LLVM bitcode.
//
//===----------------------------------------------------------------------===//
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Pass.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Support/IRReader.h"
#include "llvm/CodeGen/LinkAllAsmWriterComponents.h"
#include "llvm/CodeGen/LinkAllCodegenComponents.h"
#include "llvm/Config/config.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/PluginLoader.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include <memory>
using namespace llvm;
// General options for llc. Other pass-specific options are specified
// within the corresponding llc passes, and target-specific options
// and back-end code generation options are specified with the target machine.
//
static cl::opt<std::string>
InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
static cl::opt<std::string>
OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
// Determine optimization level.
static cl::opt<char>
OptLevel("O",
cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
"(default = '-O2')"),
cl::Prefix,
cl::ZeroOrMore,
cl::init(' '));
static cl::opt<std::string>
TargetTriple("mtriple", cl::desc("Override target triple for module"));
static cl::opt<std::string>
MArch("march", cl::desc("Architecture to generate code for (see --version)"));
static cl::opt<std::string>
MCPU("mcpu",
cl::desc("Target a specific cpu type (-mcpu=help for details)"),
cl::value_desc("cpu-name"),
cl::init(""));
static cl::list<std::string>
MAttrs("mattr",
cl::CommaSeparated,
cl::desc("Target specific attributes (-mattr=help for details)"),
cl::value_desc("a1,+a2,-a3,..."));
static cl::opt<Reloc::Model>
RelocModel("relocation-model",
cl::desc("Choose relocation model"),
cl::init(Reloc::Default),
cl::values(
clEnumValN(Reloc::Default, "default",
"Target default relocation model"),
clEnumValN(Reloc::Static, "static",
"Non-relocatable code"),
clEnumValN(Reloc::PIC_, "pic",
"Fully relocatable, position independent code"),
clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
"Relocatable external references, non-relocatable code"),
clEnumValEnd));
static cl::opt<llvm::CodeModel::Model>
CMModel("code-model",
cl::desc("Choose code model"),
cl::init(CodeModel::Default),
cl::values(clEnumValN(CodeModel::Default, "default",
"Target default code model"),
clEnumValN(CodeModel::Small, "small",
"Small code model"),
clEnumValN(CodeModel::Kernel, "kernel",
"Kernel code model"),
clEnumValN(CodeModel::Medium, "medium",
"Medium code model"),
clEnumValN(CodeModel::Large, "large",
"Large code model"),
clEnumValEnd));
static cl::opt<bool>
RelaxAll("mc-relax-all",
cl::desc("When used with filetype=obj, "
"relax all fixups in the emitted object file"));
cl::opt<TargetMachine::CodeGenFileType>
FileType("filetype", cl::init(TargetMachine::CGFT_AssemblyFile),
cl::desc("Choose a file type (not all types are supported by all targets):"),
cl::values(
clEnumValN(TargetMachine::CGFT_AssemblyFile, "asm",
"Emit an assembly ('.s') file"),
clEnumValN(TargetMachine::CGFT_ObjectFile, "obj",
"Emit a native object ('.o') file [experimental]"),
clEnumValN(TargetMachine::CGFT_Null, "null",
"Emit nothing, for performance testing"),
clEnumValEnd));
cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
cl::desc("Do not verify input module"));
cl::opt<bool> DisableDotLoc("disable-dot-loc", cl::Hidden,
cl::desc("Do not use .loc entries"));
cl::opt<bool> DisableCFI("disable-cfi", cl::Hidden,
cl::desc("Do not use .cfi_* directives"));
cl::opt<bool> EnableDwarfDirectory("enable-dwarf-directory", cl::Hidden,
cl::desc("Use .file directives with an explicit directory."));
static cl::opt<bool>
DisableRedZone("disable-red-zone",
cl::desc("Do not emit code that uses the red zone."),
cl::init(false));
// GetFileNameRoot - Helper function to get the basename of a filename.
static inline std::string
GetFileNameRoot(const std::string &InputFilename) {
std::string IFN = InputFilename;
std::string outputFilename;
int Len = IFN.length();
if ((Len > 2) &&
IFN[Len-3] == '.' &&
((IFN[Len-2] == 'b' && IFN[Len-1] == 'c') ||
(IFN[Len-2] == 'l' && IFN[Len-1] == 'l'))) {
outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
} else {
outputFilename = IFN;
}
return outputFilename;
}
static tool_output_file *GetOutputStream(const char *TargetName,
Triple::OSType OS,
const char *ProgName) {
// If we don't yet have an output filename, make one.
if (OutputFilename.empty()) {
if (InputFilename == "-")
OutputFilename = "-";
else {
OutputFilename = GetFileNameRoot(InputFilename);
switch (FileType) {
default: assert(0 && "Unknown file type");
case TargetMachine::CGFT_AssemblyFile:
if (TargetName[0] == 'c') {
if (TargetName[1] == 0)
OutputFilename += ".cbe.c";
else if (TargetName[1] == 'p' && TargetName[2] == 'p')
OutputFilename += ".cpp";
else
OutputFilename += ".s";
} else
OutputFilename += ".s";
break;
case TargetMachine::CGFT_ObjectFile:
if (OS == Triple::Win32)
OutputFilename += ".obj";
else
OutputFilename += ".o";
break;
case TargetMachine::CGFT_Null:
OutputFilename += ".null";
break;
}
}
}
// Decide if we need "binary" output.
bool Binary = false;
switch (FileType) {
default: assert(0 && "Unknown file type");
case TargetMachine::CGFT_AssemblyFile:
break;
case TargetMachine::CGFT_ObjectFile:
case TargetMachine::CGFT_Null:
Binary = true;
break;
}
// Open the file.
std::string error;
unsigned OpenFlags = 0;
if (Binary) OpenFlags |= raw_fd_ostream::F_Binary;
tool_output_file *FDOut = new tool_output_file(OutputFilename.c_str(), error,
OpenFlags);
if (!error.empty()) {
errs() << error << '\n';
delete FDOut;
return 0;
}
return FDOut;
}
// main - Entry point for the llc compiler.
//
int main(int argc, char **argv) {
sys::PrintStackTraceOnErrorSignal();
PrettyStackTraceProgram X(argc, argv);
// Enable debug stream buffering.
EnableDebugBuffering = true;
LLVMContext &Context = getGlobalContext();
llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
// Initialize targets first, so that --version shows registered targets.
InitializeAllTargets();
InitializeAllTargetMCs();
InitializeAllAsmPrinters();
InitializeAllAsmParsers();
// Register the target printer for --version.
cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
// Load the module to be compiled...
SMDiagnostic Err;
std::auto_ptr<Module> M;
M.reset(ParseIRFile(InputFilename, Err, Context));
if (M.get() == 0) {
Err.print(argv[0], errs());
return 1;
}
Module &mod = *M.get();
// If we are supposed to override the target triple, do so now.
if (!TargetTriple.empty())
mod.setTargetTriple(Triple::normalize(TargetTriple));
Triple TheTriple(mod.getTargetTriple());
if (TheTriple.getTriple().empty())
TheTriple.setTriple(sys::getDefaultTargetTriple());
// Allocate target machine. First, check whether the user has explicitly
// specified an architecture to compile for. If so we have to look it up by
// name, because it might be a backend that has no mapping to a target triple.
const Target *TheTarget = 0;
if (!MArch.empty()) {
for (TargetRegistry::iterator it = TargetRegistry::begin(),
ie = TargetRegistry::end(); it != ie; ++it) {
if (MArch == it->getName()) {
TheTarget = &*it;
break;
}
}
if (!TheTarget) {
errs() << argv[0] << ": error: invalid target '" << MArch << "'.\n";
return 1;
}
// Adjust the triple to match (if known), otherwise stick with the
// module/host triple.
Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch);
if (Type != Triple::UnknownArch)
TheTriple.setArch(Type);
} else {
std::string Err;
TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Err);
if (TheTarget == 0) {
errs() << argv[0] << ": error auto-selecting target for module '"
<< Err << "'. Please use the -march option to explicitly "
<< "pick a target.\n";
return 1;
}
}
// Package up features to be passed to target/subtarget
std::string FeaturesStr;
if (MAttrs.size()) {
SubtargetFeatures Features;
for (unsigned i = 0; i != MAttrs.size(); ++i)
Features.AddFeature(MAttrs[i]);
FeaturesStr = Features.getString();
}
CodeGenOpt::Level OLvl = CodeGenOpt::Default;
switch (OptLevel) {
default:
errs() << argv[0] << ": invalid optimization level.\n";
return 1;
case ' ': break;
case '0': OLvl = CodeGenOpt::None; break;
case '1': OLvl = CodeGenOpt::Less; break;
case '2': OLvl = CodeGenOpt::Default; break;
case '3': OLvl = CodeGenOpt::Aggressive; break;
}
std::auto_ptr<TargetMachine>
target(TheTarget->createTargetMachine(TheTriple.getTriple(),
MCPU, FeaturesStr,
RelocModel, CMModel, OLvl));
assert(target.get() && "Could not allocate target machine!");
TargetMachine &Target = *target.get();
if (DisableDotLoc)
Target.setMCUseLoc(false);
if (DisableCFI)
Target.setMCUseCFI(false);
if (EnableDwarfDirectory)
Target.setMCUseDwarfDirectory(true);
// Disable .loc support for older OS X versions.
if (TheTriple.isMacOSX() &&
TheTriple.isMacOSXVersionLT(10, 6))
Target.setMCUseLoc(false);
// Figure out where we are going to send the output...
OwningPtr<tool_output_file> Out
(GetOutputStream(TheTarget->getName(), TheTriple.getOS(), argv[0]));
if (!Out) return 1;
// Build up all of the passes that we want to do to the module.
PassManager PM;
// Add the target data from the target machine, if it exists, or the module.
if (const TargetData *TD = Target.getTargetData())
PM.add(new TargetData(*TD));
else
PM.add(new TargetData(&mod));
// Override default to generate verbose assembly.
Target.setAsmVerbosityDefault(true);
if (RelaxAll) {
if (FileType != TargetMachine::CGFT_ObjectFile)
errs() << argv[0]
<< ": warning: ignoring -mc-relax-all because filetype != obj";
else
Target.setMCRelaxAll(true);
}
{
formatted_raw_ostream FOS(Out->os());
// Ask the target to add backend passes as necessary.
if (Target.addPassesToEmitFile(PM, FOS, FileType, NoVerify)) {
errs() << argv[0] << ": target does not support generation of this"
<< " file type!\n";
return 1;
}
// Before executing passes, print the final values of the LLVM options.
cl::PrintOptionValues();
PM.run(mod);
}
// Declare success.
Out->keep();
return 0;
}