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/Support/CommandLine.h"
26 #include "llvm/Support/Debug.h"
27 #include "llvm/Support/FormattedStream.h"
28 #include "llvm/Support/ManagedStatic.h"
29 #include "llvm/Support/PluginLoader.h"
30 #include "llvm/Support/PrettyStackTrace.h"
31 #include "llvm/Support/ToolOutputFile.h"
32 #include "llvm/Support/Host.h"
33 #include "llvm/Support/Signals.h"
34 #include "llvm/Target/SubtargetFeature.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."),
111 NoImplicitFloats("no-implicit-float",
112 cl::desc("Don't generate implicit floating point instructions (x86-only)"),
115 // GetFileNameRoot - Helper function to get the basename of a filename.
116 static inline std::string
117 GetFileNameRoot(const std::string &InputFilename) {
118 std::string IFN = InputFilename;
119 std::string outputFilename;
120 int Len = IFN.length();
123 ((IFN[Len-2] == 'b' && IFN[Len-1] == 'c') ||
124 (IFN[Len-2] == 'l' && IFN[Len-1] == 'l'))) {
125 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
127 outputFilename = IFN;
129 return outputFilename;
132 static tool_output_file *GetOutputStream(const char *TargetName,
134 const char *ProgName) {
135 // If we don't yet have an output filename, make one.
136 if (OutputFilename.empty()) {
137 if (InputFilename == "-")
138 OutputFilename = "-";
140 OutputFilename = GetFileNameRoot(InputFilename);
143 default: assert(0 && "Unknown file type");
144 case TargetMachine::CGFT_AssemblyFile:
145 if (TargetName[0] == 'c') {
146 if (TargetName[1] == 0)
147 OutputFilename += ".cbe.c";
148 else if (TargetName[1] == 'p' && TargetName[2] == 'p')
149 OutputFilename += ".cpp";
151 OutputFilename += ".s";
153 OutputFilename += ".s";
155 case TargetMachine::CGFT_ObjectFile:
156 if (OS == Triple::Win32)
157 OutputFilename += ".obj";
159 OutputFilename += ".o";
161 case TargetMachine::CGFT_Null:
162 OutputFilename += ".null";
168 // Decide if we need "binary" output.
171 default: assert(0 && "Unknown file type");
172 case TargetMachine::CGFT_AssemblyFile:
174 case TargetMachine::CGFT_ObjectFile:
175 case TargetMachine::CGFT_Null:
182 unsigned OpenFlags = 0;
183 if (Binary) OpenFlags |= raw_fd_ostream::F_Binary;
184 tool_output_file *FDOut = new tool_output_file(OutputFilename.c_str(), error,
186 if (!error.empty()) {
187 errs() << error << '\n';
195 // main - Entry point for the llc compiler.
197 int main(int argc, char **argv) {
198 sys::PrintStackTraceOnErrorSignal();
199 PrettyStackTraceProgram X(argc, argv);
201 // Enable debug stream buffering.
202 EnableDebugBuffering = true;
204 LLVMContext &Context = getGlobalContext();
205 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
207 // Initialize targets first, so that --version shows registered targets.
208 InitializeAllTargets();
209 InitializeAllAsmPrinters();
210 InitializeAllAsmParsers();
212 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
214 // Load the module to be compiled...
216 std::auto_ptr<Module> M;
218 M.reset(ParseIRFile(InputFilename, Err, Context));
220 Err.Print(argv[0], errs());
223 Module &mod = *M.get();
225 // If we are supposed to override the target triple, do so now.
226 if (!TargetTriple.empty())
227 mod.setTargetTriple(Triple::normalize(TargetTriple));
229 Triple TheTriple(mod.getTargetTriple());
230 if (TheTriple.getTriple().empty())
231 TheTriple.setTriple(sys::getHostTriple());
233 // Allocate target machine. First, check whether the user has explicitly
234 // specified an architecture to compile for. If so we have to look it up by
235 // name, because it might be a backend that has no mapping to a target triple.
236 const Target *TheTarget = 0;
237 if (!MArch.empty()) {
238 for (TargetRegistry::iterator it = TargetRegistry::begin(),
239 ie = TargetRegistry::end(); it != ie; ++it) {
240 if (MArch == it->getName()) {
247 errs() << argv[0] << ": error: invalid target '" << MArch << "'.\n";
251 // Adjust the triple to match (if known), otherwise stick with the
252 // module/host triple.
253 Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch);
254 if (Type != Triple::UnknownArch)
255 TheTriple.setArch(Type);
258 TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Err);
259 if (TheTarget == 0) {
260 errs() << argv[0] << ": error auto-selecting target for module '"
261 << Err << "'. Please use the -march option to explicitly "
262 << "pick a target.\n";
267 // Package up features to be passed to target/subtarget
268 std::string FeaturesStr;
269 if (MCPU.size() || MAttrs.size()) {
270 SubtargetFeatures Features;
271 Features.setCPU(MCPU);
272 for (unsigned i = 0; i != MAttrs.size(); ++i)
273 Features.AddFeature(MAttrs[i]);
274 FeaturesStr = Features.getString();
277 std::auto_ptr<TargetMachine>
278 target(TheTarget->createTargetMachine(TheTriple.getTriple(), FeaturesStr));
279 assert(target.get() && "Could not allocate target machine!");
280 TargetMachine &Target = *target.get();
283 Target.setMCUseLoc(false);
286 Target.setMCUseCFI(false);
288 // Disable .loc support for older OS X versions.
289 if (TheTriple.isMacOSX() &&
290 TheTriple.isMacOSXVersionLT(10, 6))
291 Target.setMCUseLoc(false);
293 // Figure out where we are going to send the output...
294 OwningPtr<tool_output_file> Out
295 (GetOutputStream(TheTarget->getName(), TheTriple.getOS(), argv[0]));
298 CodeGenOpt::Level OLvl = CodeGenOpt::Default;
301 errs() << argv[0] << ": invalid optimization level.\n";
304 case '0': OLvl = CodeGenOpt::None; break;
305 case '1': OLvl = CodeGenOpt::Less; break;
306 case '2': OLvl = CodeGenOpt::Default; break;
307 case '3': OLvl = CodeGenOpt::Aggressive; break;
310 // Build up all of the passes that we want to do to the module.
313 // Add the target data from the target machine, if it exists, or the module.
314 if (const TargetData *TD = Target.getTargetData())
315 PM.add(new TargetData(*TD));
317 PM.add(new TargetData(&mod));
319 // Override default to generate verbose assembly.
320 Target.setAsmVerbosityDefault(true);
323 if (FileType != TargetMachine::CGFT_ObjectFile)
325 << ": warning: ignoring -mc-relax-all because filetype != obj";
327 Target.setMCRelaxAll(true);
331 formatted_raw_ostream FOS(Out->os());
333 // Ask the target to add backend passes as necessary.
334 if (Target.addPassesToEmitFile(PM, FOS, FileType, OLvl, NoVerify)) {
335 errs() << argv[0] << ": target does not support generation of this"
340 // Before executing passes, print the final values of the LLVM options.
341 cl::PrintOptionValues();