1 //===-- llc.cpp - Implement the LLVM Native Code Generator ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is the llc code generator driver. It provides a convenient
11 // command-line interface for generating native assembly-language code
12 // or C code, given LLVM bitcode.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/LLVMContext.h"
17 #include "llvm/Module.h"
18 #include "llvm/PassManager.h"
19 #include "llvm/Pass.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/Support/IRReader.h"
22 #include "llvm/CodeGen/LinkAllAsmWriterComponents.h"
23 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
24 #include "llvm/Config/config.h"
25 #include "llvm/MC/SubtargetFeature.h"
26 #include "llvm/Support/CommandLine.h"
27 #include "llvm/Support/Debug.h"
28 #include "llvm/Support/FormattedStream.h"
29 #include "llvm/Support/ManagedStatic.h"
30 #include "llvm/Support/PluginLoader.h"
31 #include "llvm/Support/PrettyStackTrace.h"
32 #include "llvm/Support/ToolOutputFile.h"
33 #include "llvm/Support/Host.h"
34 #include "llvm/Support/Signals.h"
35 #include "llvm/Target/TargetData.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetRegistry.h"
38 #include "llvm/Target/TargetSelect.h"
42 // General options for llc. Other pass-specific options are specified
43 // within the corresponding llc passes, and target-specific options
44 // and back-end code generation options are specified with the target machine.
46 static cl::opt<std::string>
47 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
49 static cl::opt<std::string>
50 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
52 // Determine optimization level.
55 cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
61 static cl::opt<std::string>
62 TargetTriple("mtriple", cl::desc("Override target triple for module"));
64 static cl::opt<std::string>
65 MArch("march", cl::desc("Architecture to generate code for (see --version)"));
67 static cl::opt<std::string>
69 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
70 cl::value_desc("cpu-name"),
73 static cl::list<std::string>
76 cl::desc("Target specific attributes (-mattr=help for details)"),
77 cl::value_desc("a1,+a2,-a3,..."));
80 RelaxAll("mc-relax-all",
81 cl::desc("When used with filetype=obj, "
82 "relax all fixups in the emitted object file"));
84 cl::opt<TargetMachine::CodeGenFileType>
85 FileType("filetype", cl::init(TargetMachine::CGFT_AssemblyFile),
86 cl::desc("Choose a file type (not all types are supported by all targets):"),
88 clEnumValN(TargetMachine::CGFT_AssemblyFile, "asm",
89 "Emit an assembly ('.s') file"),
90 clEnumValN(TargetMachine::CGFT_ObjectFile, "obj",
91 "Emit a native object ('.o') file [experimental]"),
92 clEnumValN(TargetMachine::CGFT_Null, "null",
93 "Emit nothing, for performance testing"),
96 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
97 cl::desc("Do not verify input module"));
99 cl::opt<bool> DisableDotLoc("disable-dot-loc", cl::Hidden,
100 cl::desc("Do not use .loc entries"));
102 cl::opt<bool> DisableCFI("disable-cfi", cl::Hidden,
103 cl::desc("Do not use .cfi_* directives"));
106 DisableRedZone("disable-red-zone",
107 cl::desc("Do not emit code that uses the red zone."),
110 // GetFileNameRoot - Helper function to get the basename of a filename.
111 static inline std::string
112 GetFileNameRoot(const std::string &InputFilename) {
113 std::string IFN = InputFilename;
114 std::string outputFilename;
115 int Len = IFN.length();
118 ((IFN[Len-2] == 'b' && IFN[Len-1] == 'c') ||
119 (IFN[Len-2] == 'l' && IFN[Len-1] == 'l'))) {
120 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
122 outputFilename = IFN;
124 return outputFilename;
127 static tool_output_file *GetOutputStream(const char *TargetName,
129 const char *ProgName) {
130 // If we don't yet have an output filename, make one.
131 if (OutputFilename.empty()) {
132 if (InputFilename == "-")
133 OutputFilename = "-";
135 OutputFilename = GetFileNameRoot(InputFilename);
138 default: assert(0 && "Unknown file type");
139 case TargetMachine::CGFT_AssemblyFile:
140 if (TargetName[0] == 'c') {
141 if (TargetName[1] == 0)
142 OutputFilename += ".cbe.c";
143 else if (TargetName[1] == 'p' && TargetName[2] == 'p')
144 OutputFilename += ".cpp";
146 OutputFilename += ".s";
148 OutputFilename += ".s";
150 case TargetMachine::CGFT_ObjectFile:
151 if (OS == Triple::Win32)
152 OutputFilename += ".obj";
154 OutputFilename += ".o";
156 case TargetMachine::CGFT_Null:
157 OutputFilename += ".null";
163 // Decide if we need "binary" output.
166 default: assert(0 && "Unknown file type");
167 case TargetMachine::CGFT_AssemblyFile:
169 case TargetMachine::CGFT_ObjectFile:
170 case TargetMachine::CGFT_Null:
177 unsigned OpenFlags = 0;
178 if (Binary) OpenFlags |= raw_fd_ostream::F_Binary;
179 tool_output_file *FDOut = new tool_output_file(OutputFilename.c_str(), error,
181 if (!error.empty()) {
182 errs() << error << '\n';
190 // main - Entry point for the llc compiler.
192 int main(int argc, char **argv) {
193 sys::PrintStackTraceOnErrorSignal();
194 PrettyStackTraceProgram X(argc, argv);
196 // Enable debug stream buffering.
197 EnableDebugBuffering = true;
199 LLVMContext &Context = getGlobalContext();
200 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
202 // Initialize targets first, so that --version shows registered targets.
203 InitializeAllTargets();
204 InitializeAllMCAsmInfos();
205 InitializeAllMCSubtargetInfos();
206 InitializeAllAsmPrinters();
207 InitializeAllAsmParsers();
209 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
211 // Load the module to be compiled...
213 std::auto_ptr<Module> M;
215 M.reset(ParseIRFile(InputFilename, Err, Context));
217 Err.Print(argv[0], errs());
220 Module &mod = *M.get();
222 // If we are supposed to override the target triple, do so now.
223 if (!TargetTriple.empty())
224 mod.setTargetTriple(Triple::normalize(TargetTriple));
226 Triple TheTriple(mod.getTargetTriple());
227 if (TheTriple.getTriple().empty())
228 TheTriple.setTriple(sys::getHostTriple());
230 // Allocate target machine. First, check whether the user has explicitly
231 // specified an architecture to compile for. If so we have to look it up by
232 // name, because it might be a backend that has no mapping to a target triple.
233 const Target *TheTarget = 0;
234 if (!MArch.empty()) {
235 for (TargetRegistry::iterator it = TargetRegistry::begin(),
236 ie = TargetRegistry::end(); it != ie; ++it) {
237 if (MArch == it->getName()) {
244 errs() << argv[0] << ": error: invalid target '" << MArch << "'.\n";
248 // Adjust the triple to match (if known), otherwise stick with the
249 // module/host triple.
250 Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch);
251 if (Type != Triple::UnknownArch)
252 TheTriple.setArch(Type);
255 TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Err);
256 if (TheTarget == 0) {
257 errs() << argv[0] << ": error auto-selecting target for module '"
258 << Err << "'. Please use the -march option to explicitly "
259 << "pick a target.\n";
264 // Package up features to be passed to target/subtarget
265 std::string FeaturesStr;
267 SubtargetFeatures Features;
268 for (unsigned i = 0; i != MAttrs.size(); ++i)
269 Features.AddFeature(MAttrs[i]);
270 FeaturesStr = Features.getString();
273 std::auto_ptr<TargetMachine>
274 target(TheTarget->createTargetMachine(TheTriple.getTriple(), MCPU,
276 assert(target.get() && "Could not allocate target machine!");
277 TargetMachine &Target = *target.get();
280 Target.setMCUseLoc(false);
283 Target.setMCUseCFI(false);
285 // Disable .loc support for older OS X versions.
286 if (TheTriple.isMacOSX() &&
287 TheTriple.isMacOSXVersionLT(10, 6))
288 Target.setMCUseLoc(false);
290 // Figure out where we are going to send the output...
291 OwningPtr<tool_output_file> Out
292 (GetOutputStream(TheTarget->getName(), TheTriple.getOS(), argv[0]));
295 CodeGenOpt::Level OLvl = CodeGenOpt::Default;
298 errs() << argv[0] << ": invalid optimization level.\n";
301 case '0': OLvl = CodeGenOpt::None; break;
302 case '1': OLvl = CodeGenOpt::Less; break;
303 case '2': OLvl = CodeGenOpt::Default; break;
304 case '3': OLvl = CodeGenOpt::Aggressive; break;
307 // Build up all of the passes that we want to do to the module.
310 // Add the target data from the target machine, if it exists, or the module.
311 if (const TargetData *TD = Target.getTargetData())
312 PM.add(new TargetData(*TD));
314 PM.add(new TargetData(&mod));
316 // Override default to generate verbose assembly.
317 Target.setAsmVerbosityDefault(true);
320 if (FileType != TargetMachine::CGFT_ObjectFile)
322 << ": warning: ignoring -mc-relax-all because filetype != obj";
324 Target.setMCRelaxAll(true);
328 formatted_raw_ostream FOS(Out->os());
330 // Ask the target to add backend passes as necessary.
331 if (Target.addPassesToEmitFile(PM, FOS, FileType, OLvl, NoVerify)) {
332 errs() << argv[0] << ": target does not support generation of this"
337 // Before executing passes, print the final values of the LLVM options.
338 cl::PrintOptionValues();