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#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/Assembly/PrintModulePass.h" 22#include "llvm/Support/IRReader.h" 23#include "llvm/CodeGen/LinkAllAsmWriterComponents.h" 24#include "llvm/CodeGen/LinkAllCodegenComponents.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/Support/TargetRegistry.h" 36#include "llvm/Support/TargetSelect.h" 37#include "llvm/Target/TargetData.h" 38#include "llvm/Target/TargetLibraryInfo.h" 39#include "llvm/Target/TargetMachine.h" 40#include <memory> 41using namespace llvm; 42 43// General options for llc. Other pass-specific options are specified 44// within the corresponding llc passes, and target-specific options 45// and back-end code generation options are specified with the target machine. 46// 47static cl::opt<std::string> 48InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-")); 49 50static cl::opt<std::string> 51OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename")); 52 53// Determine optimization level. 54static cl::opt<char> 55OptLevel("O", 56 cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] " 57 "(default = '-O2')"), 58 cl::Prefix, 59 cl::ZeroOrMore, 60 cl::init(' ')); 61 62static cl::opt<std::string> 63TargetTriple("mtriple", cl::desc("Override target triple for module")); 64 65static cl::opt<std::string> 66MArch("march", cl::desc("Architecture to generate code for (see --version)")); 67 68static cl::opt<std::string> 69MCPU("mcpu", 70 cl::desc("Target a specific cpu type (-mcpu=help for details)"), 71 cl::value_desc("cpu-name"), 72 cl::init("")); 73 74static cl::list<std::string> 75MAttrs("mattr", 76 cl::CommaSeparated, 77 cl::desc("Target specific attributes (-mattr=help for details)"), 78 cl::value_desc("a1,+a2,-a3,...")); 79 80static cl::opt<Reloc::Model> 81RelocModel("relocation-model", 82 cl::desc("Choose relocation model"), 83 cl::init(Reloc::Default), 84 cl::values( 85 clEnumValN(Reloc::Default, "default", 86 "Target default relocation model"), 87 clEnumValN(Reloc::Static, "static", 88 "Non-relocatable code"), 89 clEnumValN(Reloc::PIC_, "pic", 90 "Fully relocatable, position independent code"), 91 clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic", 92 "Relocatable external references, non-relocatable code"), 93 clEnumValEnd)); 94 95static cl::opt<llvm::CodeModel::Model> 96CMModel("code-model", 97 cl::desc("Choose code model"), 98 cl::init(CodeModel::Default), 99 cl::values(clEnumValN(CodeModel::Default, "default", 100 "Target default code model"), 101 clEnumValN(CodeModel::Small, "small", 102 "Small code model"), 103 clEnumValN(CodeModel::Kernel, "kernel", 104 "Kernel code model"), 105 clEnumValN(CodeModel::Medium, "medium", 106 "Medium code model"), 107 clEnumValN(CodeModel::Large, "large", 108 "Large code model"), 109 clEnumValEnd)); 110 111static cl::opt<bool> 112RelaxAll("mc-relax-all", 113 cl::desc("When used with filetype=obj, " 114 "relax all fixups in the emitted object file")); 115 116cl::opt<TargetMachine::CodeGenFileType> 117FileType("filetype", cl::init(TargetMachine::CGFT_AssemblyFile), 118 cl::desc("Choose a file type (not all types are supported by all targets):"), 119 cl::values( 120 clEnumValN(TargetMachine::CGFT_AssemblyFile, "asm", 121 "Emit an assembly ('.s') file"), 122 clEnumValN(TargetMachine::CGFT_ObjectFile, "obj", 123 "Emit a native object ('.o') file"), 124 clEnumValN(TargetMachine::CGFT_Null, "null", 125 "Emit nothing, for performance testing"), 126 clEnumValEnd)); 127 128cl::opt<bool> NoVerify("disable-verify", cl::Hidden, 129 cl::desc("Do not verify input module")); 130 131cl::opt<bool> DisableDotLoc("disable-dot-loc", cl::Hidden, 132 cl::desc("Do not use .loc entries")); 133 134cl::opt<bool> DisableCFI("disable-cfi", cl::Hidden, 135 cl::desc("Do not use .cfi_* directives")); 136 137cl::opt<bool> EnableDwarfDirectory("enable-dwarf-directory", cl::Hidden, 138 cl::desc("Use .file directives with an explicit directory.")); 139 140static cl::opt<bool> 141DisableRedZone("disable-red-zone", 142 cl::desc("Do not emit code that uses the red zone."), 143 cl::init(false)); 144 145static cl::opt<bool> 146EnableFPMAD("enable-fp-mad", 147 cl::desc("Enable less precise MAD instructions to be generated"), 148 cl::init(false)); 149 150static cl::opt<bool> 151DisableFPElim("disable-fp-elim", 152 cl::desc("Disable frame pointer elimination optimization"), 153 cl::init(false)); 154 155static cl::opt<bool> 156DisableFPElimNonLeaf("disable-non-leaf-fp-elim", 157 cl::desc("Disable frame pointer elimination optimization for non-leaf funcs"), 158 cl::init(false)); 159 160static cl::opt<bool> 161EnableUnsafeFPMath("enable-unsafe-fp-math", 162 cl::desc("Enable optimizations that may decrease FP precision"), 163 cl::init(false)); 164 165static cl::opt<bool> 166EnableNoInfsFPMath("enable-no-infs-fp-math", 167 cl::desc("Enable FP math optimizations that assume no +-Infs"), 168 cl::init(false)); 169 170static cl::opt<bool> 171EnableNoNaNsFPMath("enable-no-nans-fp-math", 172 cl::desc("Enable FP math optimizations that assume no NaNs"), 173 cl::init(false)); 174 175static cl::opt<bool> 176EnableHonorSignDependentRoundingFPMath("enable-sign-dependent-rounding-fp-math", 177 cl::Hidden, 178 cl::desc("Force codegen to assume rounding mode can change dynamically"), 179 cl::init(false)); 180 181static cl::opt<bool> 182GenerateSoftFloatCalls("soft-float", 183 cl::desc("Generate software floating point library calls"), 184 cl::init(false)); 185 186static cl::opt<llvm::FloatABI::ABIType> 187FloatABIForCalls("float-abi", 188 cl::desc("Choose float ABI type"), 189 cl::init(FloatABI::Default), 190 cl::values( 191 clEnumValN(FloatABI::Default, "default", 192 "Target default float ABI type"), 193 clEnumValN(FloatABI::Soft, "soft", 194 "Soft float ABI (implied by -soft-float)"), 195 clEnumValN(FloatABI::Hard, "hard", 196 "Hard float ABI (uses FP registers)"), 197 clEnumValEnd)); 198 199static cl::opt<llvm::FPOpFusion::FPOpFusionMode> 200FuseFPOps("fp-contract", 201 cl::desc("Enable aggresive formation of fused FP ops"), 202 cl::init(FPOpFusion::Standard), 203 cl::values( 204 clEnumValN(FPOpFusion::Fast, "fast", 205 "Fuse FP ops whenever profitable"), 206 clEnumValN(FPOpFusion::Standard, "on", 207 "Only fuse 'blessed' FP ops."), 208 clEnumValN(FPOpFusion::Strict, "off", 209 "Only fuse FP ops when the result won't be effected."), 210 clEnumValEnd)); 211 212static cl::opt<bool> 213DontPlaceZerosInBSS("nozero-initialized-in-bss", 214 cl::desc("Don't place zero-initialized symbols into bss section"), 215 cl::init(false)); 216 217static cl::opt<bool> 218DisableSimplifyLibCalls("disable-simplify-libcalls", 219 cl::desc("Disable simplify-libcalls"), 220 cl::init(false)); 221 222static cl::opt<bool> 223EnableGuaranteedTailCallOpt("tailcallopt", 224 cl::desc("Turn fastcc calls into tail calls by (potentially) changing ABI."), 225 cl::init(false)); 226 227static cl::opt<bool> 228DisableTailCalls("disable-tail-calls", 229 cl::desc("Never emit tail calls"), 230 cl::init(false)); 231 232static cl::opt<unsigned> 233OverrideStackAlignment("stack-alignment", 234 cl::desc("Override default stack alignment"), 235 cl::init(0)); 236 237static cl::opt<bool> 238EnableRealignStack("realign-stack", 239 cl::desc("Realign stack if needed"), 240 cl::init(true)); 241 242static cl::opt<std::string> 243TrapFuncName("trap-func", cl::Hidden, 244 cl::desc("Emit a call to trap function rather than a trap instruction"), 245 cl::init("")); 246 247static cl::opt<bool> 248EnablePIE("enable-pie", 249 cl::desc("Assume the creation of a position independent executable."), 250 cl::init(false)); 251 252static cl::opt<bool> 253SegmentedStacks("segmented-stacks", 254 cl::desc("Use segmented stacks if possible."), 255 cl::init(false)); 256 257static cl::opt<bool> 258UseInitArray("use-init-array", 259 cl::desc("Use .init_array instead of .ctors."), 260 cl::init(false)); 261 262static cl::opt<std::string> StopAfter("stop-after", 263 cl::desc("Stop compilation after a specific pass"), 264 cl::value_desc("pass-name"), 265 cl::init("")); 266static cl::opt<std::string> StartAfter("start-after", 267 cl::desc("Resume compilation after a specific pass"), 268 cl::value_desc("pass-name"), 269 cl::init("")); 270 271static cl::opt<unsigned> 272SSPBufferSize("stack-protector-buffer-size", cl::init(8), 273 cl::desc("Lower bound for a buffer to be considered for " 274 "stack protection")); 275 276// GetFileNameRoot - Helper function to get the basename of a filename. 277static inline std::string 278GetFileNameRoot(const std::string &InputFilename) { 279 std::string IFN = InputFilename; 280 std::string outputFilename; 281 int Len = IFN.length(); 282 if ((Len > 2) && 283 IFN[Len-3] == '.' && 284 ((IFN[Len-2] == 'b' && IFN[Len-1] == 'c') || 285 (IFN[Len-2] == 'l' && IFN[Len-1] == 'l'))) { 286 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/ 287 } else { 288 outputFilename = IFN; 289 } 290 return outputFilename; 291} 292 293static tool_output_file *GetOutputStream(const char *TargetName, 294 Triple::OSType OS, 295 const char *ProgName) { 296 // If we don't yet have an output filename, make one. 297 if (OutputFilename.empty()) { 298 if (InputFilename == "-") 299 OutputFilename = "-"; 300 else { 301 OutputFilename = GetFileNameRoot(InputFilename); 302 303 switch (FileType) { 304 case TargetMachine::CGFT_AssemblyFile: 305 if (TargetName[0] == 'c') { 306 if (TargetName[1] == 0) 307 OutputFilename += ".cbe.c"; 308 else if (TargetName[1] == 'p' && TargetName[2] == 'p') 309 OutputFilename += ".cpp"; 310 else 311 OutputFilename += ".s"; 312 } else 313 OutputFilename += ".s"; 314 break; 315 case TargetMachine::CGFT_ObjectFile: 316 if (OS == Triple::Win32) 317 OutputFilename += ".obj"; 318 else 319 OutputFilename += ".o"; 320 break; 321 case TargetMachine::CGFT_Null: 322 OutputFilename += ".null"; 323 break; 324 } 325 } 326 } 327 328 // Decide if we need "binary" output. 329 bool Binary = false; 330 switch (FileType) { 331 case TargetMachine::CGFT_AssemblyFile: 332 break; 333 case TargetMachine::CGFT_ObjectFile: 334 case TargetMachine::CGFT_Null: 335 Binary = true; 336 break; 337 } 338 339 // Open the file. 340 std::string error; 341 unsigned OpenFlags = 0; 342 if (Binary) OpenFlags |= raw_fd_ostream::F_Binary; 343 tool_output_file *FDOut = new tool_output_file(OutputFilename.c_str(), error, 344 OpenFlags); 345 if (!error.empty()) { 346 errs() << error << '\n'; 347 delete FDOut; 348 return 0; 349 } 350 351 return FDOut; 352} 353 354// main - Entry point for the llc compiler. 355// 356int main(int argc, char **argv) { 357 sys::PrintStackTraceOnErrorSignal(); 358 PrettyStackTraceProgram X(argc, argv); 359 360 // Enable debug stream buffering. 361 EnableDebugBuffering = true; 362 363 LLVMContext &Context = getGlobalContext(); 364 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit. 365 366 // Initialize targets first, so that --version shows registered targets. 367 InitializeAllTargets(); 368 InitializeAllTargetMCs(); 369 InitializeAllAsmPrinters(); 370 InitializeAllAsmParsers(); 371 372 // Initialize codegen and IR passes used by llc so that the -print-after, 373 // -print-before, and -stop-after options work. 374 PassRegistry *Registry = PassRegistry::getPassRegistry(); 375 initializeCore(*Registry); 376 initializeCodeGen(*Registry); 377 initializeLoopStrengthReducePass(*Registry); 378 initializeLowerIntrinsicsPass(*Registry); 379 initializeUnreachableBlockElimPass(*Registry); 380 381 // Register the target printer for --version. 382 cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion); 383 384 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n"); 385 386 // Load the module to be compiled... 387 SMDiagnostic Err; 388 std::auto_ptr<Module> M; 389 Module *mod = 0; 390 Triple TheTriple; 391 392 bool SkipModule = MCPU == "help" || 393 (!MAttrs.empty() && MAttrs.front() == "help"); 394 395 // If user just wants to list available options, skip module loading 396 if (!SkipModule) { 397 M.reset(ParseIRFile(InputFilename, Err, Context)); 398 mod = M.get(); 399 if (mod == 0) { 400 Err.print(argv[0], errs()); 401 return 1; 402 } 403 404 // If we are supposed to override the target triple, do so now. 405 if (!TargetTriple.empty()) 406 mod->setTargetTriple(Triple::normalize(TargetTriple)); 407 TheTriple = Triple(mod->getTargetTriple()); 408 } else { 409 TheTriple = Triple(Triple::normalize(TargetTriple)); 410 } 411 412 if (TheTriple.getTriple().empty()) 413 TheTriple.setTriple(sys::getDefaultTargetTriple()); 414 415 // Get the target specific parser. 416 std::string Error; 417 const Target *TheTarget = TargetRegistry::lookupTarget(MArch, TheTriple, 418 Error); 419 if (!TheTarget) { 420 errs() << argv[0] << ": " << Error; 421 return 1; 422 } 423 424 // Package up features to be passed to target/subtarget 425 std::string FeaturesStr; 426 if (MAttrs.size()) { 427 SubtargetFeatures Features; 428 for (unsigned i = 0; i != MAttrs.size(); ++i) 429 Features.AddFeature(MAttrs[i]); 430 FeaturesStr = Features.getString(); 431 } 432 433 CodeGenOpt::Level OLvl = CodeGenOpt::Default; 434 switch (OptLevel) { 435 default: 436 errs() << argv[0] << ": invalid optimization level.\n"; 437 return 1; 438 case ' ': break; 439 case '0': OLvl = CodeGenOpt::None; break; 440 case '1': OLvl = CodeGenOpt::Less; break; 441 case '2': OLvl = CodeGenOpt::Default; break; 442 case '3': OLvl = CodeGenOpt::Aggressive; break; 443 } 444 445 TargetOptions Options; 446 Options.LessPreciseFPMADOption = EnableFPMAD; 447 Options.NoFramePointerElim = DisableFPElim; 448 Options.NoFramePointerElimNonLeaf = DisableFPElimNonLeaf; 449 Options.AllowFPOpFusion = FuseFPOps; 450 Options.UnsafeFPMath = EnableUnsafeFPMath; 451 Options.NoInfsFPMath = EnableNoInfsFPMath; 452 Options.NoNaNsFPMath = EnableNoNaNsFPMath; 453 Options.HonorSignDependentRoundingFPMathOption = 454 EnableHonorSignDependentRoundingFPMath; 455 Options.UseSoftFloat = GenerateSoftFloatCalls; 456 if (FloatABIForCalls != FloatABI::Default) 457 Options.FloatABIType = FloatABIForCalls; 458 Options.NoZerosInBSS = DontPlaceZerosInBSS; 459 Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt; 460 Options.DisableTailCalls = DisableTailCalls; 461 Options.StackAlignmentOverride = OverrideStackAlignment; 462 Options.RealignStack = EnableRealignStack; 463 Options.TrapFuncName = TrapFuncName; 464 Options.PositionIndependentExecutable = EnablePIE; 465 Options.EnableSegmentedStacks = SegmentedStacks; 466 Options.UseInitArray = UseInitArray; 467 Options.SSPBufferSize = SSPBufferSize; 468 469 std::auto_ptr<TargetMachine> 470 target(TheTarget->createTargetMachine(TheTriple.getTriple(), 471 MCPU, FeaturesStr, Options, 472 RelocModel, CMModel, OLvl)); 473 assert(target.get() && "Could not allocate target machine!"); 474 assert(mod && "Should have exited after outputting help!"); 475 TargetMachine &Target = *target.get(); 476 477 if (DisableDotLoc) 478 Target.setMCUseLoc(false); 479 480 if (DisableCFI) 481 Target.setMCUseCFI(false); 482 483 if (EnableDwarfDirectory) 484 Target.setMCUseDwarfDirectory(true); 485 486 if (GenerateSoftFloatCalls) 487 FloatABIForCalls = FloatABI::Soft; 488 489 // Disable .loc support for older OS X versions. 490 if (TheTriple.isMacOSX() && 491 TheTriple.isMacOSXVersionLT(10, 6)) 492 Target.setMCUseLoc(false); 493 494 // Figure out where we are going to send the output. 495 OwningPtr<tool_output_file> Out 496 (GetOutputStream(TheTarget->getName(), TheTriple.getOS(), argv[0])); 497 if (!Out) return 1; 498 499 // Build up all of the passes that we want to do to the module. 500 PassManager PM; 501 502 // Add an appropriate TargetLibraryInfo pass for the module's triple. 503 TargetLibraryInfo *TLI = new TargetLibraryInfo(TheTriple); 504 if (DisableSimplifyLibCalls) 505 TLI->disableAllFunctions(); 506 PM.add(TLI); 507 508 // Add the target data from the target machine, if it exists, or the module. 509 if (const TargetData *TD = Target.getTargetData()) 510 PM.add(new TargetData(*TD)); 511 else 512 PM.add(new TargetData(mod)); 513 514 // Override default to generate verbose assembly. 515 Target.setAsmVerbosityDefault(true); 516 517 if (RelaxAll) { 518 if (FileType != TargetMachine::CGFT_ObjectFile) 519 errs() << argv[0] 520 << ": warning: ignoring -mc-relax-all because filetype != obj"; 521 else 522 Target.setMCRelaxAll(true); 523 } 524 525 { 526 formatted_raw_ostream FOS(Out->os()); 527 528 AnalysisID StartAfterID = 0; 529 AnalysisID StopAfterID = 0; 530 const PassRegistry *PR = PassRegistry::getPassRegistry(); 531 if (!StartAfter.empty()) { 532 const PassInfo *PI = PR->getPassInfo(StartAfter); 533 if (!PI) { 534 errs() << argv[0] << ": start-after pass is not registered.\n"; 535 return 1; 536 } 537 StartAfterID = PI->getTypeInfo(); 538 } 539 if (!StopAfter.empty()) { 540 const PassInfo *PI = PR->getPassInfo(StopAfter); 541 if (!PI) { 542 errs() << argv[0] << ": stop-after pass is not registered.\n"; 543 return 1; 544 } 545 StopAfterID = PI->getTypeInfo(); 546 } 547 548 // Ask the target to add backend passes as necessary. 549 if (Target.addPassesToEmitFile(PM, FOS, FileType, NoVerify, 550 StartAfterID, StopAfterID)) { 551 errs() << argv[0] << ": target does not support generation of this" 552 << " file type!\n"; 553 return 1; 554 } 555 556 // Before executing passes, print the final values of the LLVM options. 557 cl::PrintOptionValues(); 558 559 PM.run(*mod); 560 } 561 562 // Declare success. 563 Out->keep(); 564 565 return 0; 566} 567