1 //===-- llc.cpp - Implement the LLVM Native Code Generator ----------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 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. 13 // 14 //===----------------------------------------------------------------------===// 15 16 17 #include "llvm/ADT/Triple.h" 18 #include "llvm/CodeGen/CommandFlags.h" 19 #include "llvm/CodeGen/LinkAllAsmWriterComponents.h" 20 #include "llvm/CodeGen/LinkAllCodegenComponents.h" 21 #include "llvm/IR/DataLayout.h" 22 #include "llvm/IR/IRPrintingPasses.h" 23 #include "llvm/IR/LLVMContext.h" 24 #include "llvm/IR/Module.h" 25 #include "llvm/IRReader/IRReader.h" 26 #include "llvm/MC/SubtargetFeature.h" 27 #include "llvm/Pass.h" 28 #include "llvm/PassManager.h" 29 #include "llvm/Support/CommandLine.h" 30 #include "llvm/Support/Debug.h" 31 #include "llvm/Support/FormattedStream.h" 32 #include "llvm/Support/Host.h" 33 #include "llvm/Support/ManagedStatic.h" 34 #include "llvm/Support/PluginLoader.h" 35 #include "llvm/Support/PrettyStackTrace.h" 36 #include "llvm/Support/Signals.h" 37 #include "llvm/Support/SourceMgr.h" 38 #include "llvm/Support/TargetRegistry.h" 39 #include "llvm/Support/TargetSelect.h" 40 #include "llvm/Support/ToolOutputFile.h" 41 #include "llvm/Target/TargetLibraryInfo.h" 42 #include "llvm/Target/TargetMachine.h" 43 #include <memory> 44 using namespace llvm; 45 46 // General options for llc. Other pass-specific options are specified 47 // within the corresponding llc passes, and target-specific options 48 // and back-end code generation options are specified with the target machine. 49 // 50 static cl::opt<std::string> 51 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-")); 52 53 static cl::opt<std::string> 54 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename")); 55 56 static cl::opt<unsigned> 57 TimeCompilations("time-compilations", cl::Hidden, cl::init(1u), 58 cl::value_desc("N"), 59 cl::desc("Repeat compilation N times for timing")); 60 61 static cl::opt<bool> 62 NoIntegratedAssembler("no-integrated-as", cl::Hidden, 63 cl::desc("Disable integrated assembler")); 64 65 // Determine optimization level. 66 static cl::opt<char> 67 OptLevel("O", 68 cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] " 69 "(default = '-O2')"), 70 cl::Prefix, 71 cl::ZeroOrMore, 72 cl::init(' ')); 73 74 static cl::opt<std::string> 75 TargetTriple("mtriple", cl::desc("Override target triple for module")); 76 77 cl::opt<bool> NoVerify("disable-verify", cl::Hidden, 78 cl::desc("Do not verify input module")); 79 80 cl::opt<bool> 81 DisableSimplifyLibCalls("disable-simplify-libcalls", 82 cl::desc("Disable simplify-libcalls"), 83 cl::init(false)); 84 85 static int compileModule(char**, LLVMContext&); 86 87 // GetFileNameRoot - Helper function to get the basename of a filename. 88 static inline std::string 89 GetFileNameRoot(const std::string &InputFilename) { 90 std::string IFN = InputFilename; 91 std::string outputFilename; 92 int Len = IFN.length(); 93 if ((Len > 2) && 94 IFN[Len-3] == '.' && 95 ((IFN[Len-2] == 'b' && IFN[Len-1] == 'c') || 96 (IFN[Len-2] == 'l' && IFN[Len-1] == 'l'))) { 97 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/ 98 } else { 99 outputFilename = IFN; 100 } 101 return outputFilename; 102 } 103 104 static tool_output_file *GetOutputStream(const char *TargetName, 105 Triple::OSType OS, 106 const char *ProgName) { 107 // If we don't yet have an output filename, make one. 108 if (OutputFilename.empty()) { 109 if (InputFilename == "-") 110 OutputFilename = "-"; 111 else { 112 OutputFilename = GetFileNameRoot(InputFilename); 113 114 switch (FileType) { 115 case TargetMachine::CGFT_AssemblyFile: 116 if (TargetName[0] == 'c') { 117 if (TargetName[1] == 0) 118 OutputFilename += ".cbe.c"; 119 else if (TargetName[1] == 'p' && TargetName[2] == 'p') 120 OutputFilename += ".cpp"; 121 else 122 OutputFilename += ".s"; 123 } else 124 OutputFilename += ".s"; 125 break; 126 case TargetMachine::CGFT_ObjectFile: 127 if (OS == Triple::Win32) 128 OutputFilename += ".obj"; 129 else 130 OutputFilename += ".o"; 131 break; 132 case TargetMachine::CGFT_Null: 133 OutputFilename += ".null"; 134 break; 135 } 136 } 137 } 138 139 // Decide if we need "binary" output. 140 bool Binary = false; 141 switch (FileType) { 142 case TargetMachine::CGFT_AssemblyFile: 143 break; 144 case TargetMachine::CGFT_ObjectFile: 145 case TargetMachine::CGFT_Null: 146 Binary = true; 147 break; 148 } 149 150 // Open the file. 151 std::string error; 152 sys::fs::OpenFlags OpenFlags = sys::fs::F_None; 153 if (!Binary) 154 OpenFlags |= sys::fs::F_Text; 155 tool_output_file *FDOut = new tool_output_file(OutputFilename.c_str(), error, 156 OpenFlags); 157 if (!error.empty()) { 158 errs() << error << '\n'; 159 delete FDOut; 160 return 0; 161 } 162 163 return FDOut; 164 } 165 166 // main - Entry point for the llc compiler. 167 // 168 int main(int argc, char **argv) { 169 sys::PrintStackTraceOnErrorSignal(); 170 PrettyStackTraceProgram X(argc, argv); 171 172 // Enable debug stream buffering. 173 EnableDebugBuffering = true; 174 175 LLVMContext &Context = getGlobalContext(); 176 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit. 177 178 // Initialize targets first, so that --version shows registered targets. 179 InitializeAllTargets(); 180 InitializeAllTargetMCs(); 181 InitializeAllAsmPrinters(); 182 InitializeAllAsmParsers(); 183 184 // Initialize codegen and IR passes used by llc so that the -print-after, 185 // -print-before, and -stop-after options work. 186 PassRegistry *Registry = PassRegistry::getPassRegistry(); 187 initializeCore(*Registry); 188 initializeCodeGen(*Registry); 189 initializeLoopStrengthReducePass(*Registry); 190 initializeLowerIntrinsicsPass(*Registry); 191 initializeUnreachableBlockElimPass(*Registry); 192 193 // Register the target printer for --version. 194 cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion); 195 196 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n"); 197 198 // Compile the module TimeCompilations times to give better compile time 199 // metrics. 200 for (unsigned I = TimeCompilations; I; --I) 201 if (int RetVal = compileModule(argv, Context)) 202 return RetVal; 203 return 0; 204 } 205 206 static int compileModule(char **argv, LLVMContext &Context) { 207 // Load the module to be compiled... 208 SMDiagnostic Err; 209 std::unique_ptr<Module> M; 210 Module *mod = 0; 211 Triple TheTriple; 212 213 bool SkipModule = MCPU == "help" || 214 (!MAttrs.empty() && MAttrs.front() == "help"); 215 216 // If user asked for the 'native' CPU, autodetect here. If autodection fails, 217 // this will set the CPU to an empty string which tells the target to 218 // pick a basic default. 219 if (MCPU == "native") 220 MCPU = sys::getHostCPUName(); 221 222 // If user just wants to list available options, skip module loading 223 if (!SkipModule) { 224 M.reset(ParseIRFile(InputFilename, Err, Context)); 225 mod = M.get(); 226 if (mod == 0) { 227 Err.print(argv[0], errs()); 228 return 1; 229 } 230 231 // If we are supposed to override the target triple, do so now. 232 if (!TargetTriple.empty()) 233 mod->setTargetTriple(Triple::normalize(TargetTriple)); 234 TheTriple = Triple(mod->getTargetTriple()); 235 } else { 236 TheTriple = Triple(Triple::normalize(TargetTriple)); 237 } 238 239 if (TheTriple.getTriple().empty()) 240 TheTriple.setTriple(sys::getDefaultTargetTriple()); 241 242 // Get the target specific parser. 243 std::string Error; 244 const Target *TheTarget = TargetRegistry::lookupTarget(MArch, TheTriple, 245 Error); 246 if (!TheTarget) { 247 errs() << argv[0] << ": " << Error; 248 return 1; 249 } 250 251 // Package up features to be passed to target/subtarget 252 std::string FeaturesStr; 253 if (MAttrs.size()) { 254 SubtargetFeatures Features; 255 for (unsigned i = 0; i != MAttrs.size(); ++i) 256 Features.AddFeature(MAttrs[i]); 257 FeaturesStr = Features.getString(); 258 } 259 260 CodeGenOpt::Level OLvl = CodeGenOpt::Default; 261 switch (OptLevel) { 262 default: 263 errs() << argv[0] << ": invalid optimization level.\n"; 264 return 1; 265 case ' ': break; 266 case '0': OLvl = CodeGenOpt::None; break; 267 case '1': OLvl = CodeGenOpt::Less; break; 268 case '2': OLvl = CodeGenOpt::Default; break; 269 case '3': OLvl = CodeGenOpt::Aggressive; break; 270 } 271 272 TargetOptions Options = InitTargetOptionsFromCodeGenFlags(); 273 Options.DisableIntegratedAS = NoIntegratedAssembler; 274 275 std::unique_ptr<TargetMachine> target( 276 TheTarget->createTargetMachine(TheTriple.getTriple(), MCPU, FeaturesStr, 277 Options, RelocModel, CMModel, OLvl)); 278 assert(target.get() && "Could not allocate target machine!"); 279 assert(mod && "Should have exited after outputting help!"); 280 TargetMachine &Target = *target.get(); 281 282 if (DisableCFI) 283 Target.setMCUseCFI(false); 284 285 if (EnableDwarfDirectory) 286 Target.setMCUseDwarfDirectory(true); 287 288 if (GenerateSoftFloatCalls) 289 FloatABIForCalls = FloatABI::Soft; 290 291 // Figure out where we are going to send the output. 292 std::unique_ptr<tool_output_file> Out( 293 GetOutputStream(TheTarget->getName(), TheTriple.getOS(), argv[0])); 294 if (!Out) return 1; 295 296 // Build up all of the passes that we want to do to the module. 297 PassManager PM; 298 299 // Add an appropriate TargetLibraryInfo pass for the module's triple. 300 TargetLibraryInfo *TLI = new TargetLibraryInfo(TheTriple); 301 if (DisableSimplifyLibCalls) 302 TLI->disableAllFunctions(); 303 PM.add(TLI); 304 305 // Add the target data from the target machine, if it exists, or the module. 306 if (const DataLayout *DL = Target.getDataLayout()) 307 mod->setDataLayout(DL); 308 PM.add(new DataLayoutPass(mod)); 309 310 // Override default to generate verbose assembly. 311 Target.setAsmVerbosityDefault(true); 312 313 if (RelaxAll) { 314 if (FileType != TargetMachine::CGFT_ObjectFile) 315 errs() << argv[0] 316 << ": warning: ignoring -mc-relax-all because filetype != obj"; 317 else 318 Target.setMCRelaxAll(true); 319 } 320 321 { 322 formatted_raw_ostream FOS(Out->os()); 323 324 AnalysisID StartAfterID = 0; 325 AnalysisID StopAfterID = 0; 326 const PassRegistry *PR = PassRegistry::getPassRegistry(); 327 if (!StartAfter.empty()) { 328 const PassInfo *PI = PR->getPassInfo(StartAfter); 329 if (!PI) { 330 errs() << argv[0] << ": start-after pass is not registered.\n"; 331 return 1; 332 } 333 StartAfterID = PI->getTypeInfo(); 334 } 335 if (!StopAfter.empty()) { 336 const PassInfo *PI = PR->getPassInfo(StopAfter); 337 if (!PI) { 338 errs() << argv[0] << ": stop-after pass is not registered.\n"; 339 return 1; 340 } 341 StopAfterID = PI->getTypeInfo(); 342 } 343 344 // Ask the target to add backend passes as necessary. 345 if (Target.addPassesToEmitFile(PM, FOS, FileType, NoVerify, 346 StartAfterID, StopAfterID)) { 347 errs() << argv[0] << ": target does not support generation of this" 348 << " file type!\n"; 349 return 1; 350 } 351 352 // Before executing passes, print the final values of the LLVM options. 353 cl::PrintOptionValues(); 354 355 PM.run(*mod); 356 } 357 358 // Declare success. 359 Out->keep(); 360 361 return 0; 362 } 363