tools/opt/opt.cpp

   1 //===- opt.cpp - The LLVM Modular Optimizer -------------------------------===//
   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 // Optimizations may be specified an arbitrary number of times on the command
  11 // line, They are run in the order specified.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/LLVMContext.h"
  16 #include "llvm/Module.h"
  17 #include "llvm/PassManager.h"
  18 #include "llvm/CallGraphSCCPass.h"
  19 #include "llvm/Bitcode/ReaderWriter.h"
  20 #include "llvm/Assembly/PrintModulePass.h"
  21 #include "llvm/Analysis/Verifier.h"
  22 #include "llvm/Analysis/LoopPass.h"
  23 #include "llvm/Analysis/CallGraph.h"
  24 #include "llvm/Target/TargetData.h"
  25 #include "llvm/Target/TargetMachine.h"
  26 #include "llvm/Support/PassNameParser.h"
  27 #include "llvm/System/Signals.h"
  28 #include "llvm/Support/Debug.h"
  29 #include "llvm/Support/IRReader.h"
  30 #include "llvm/Support/ManagedStatic.h"
  31 #include "llvm/Support/PluginLoader.h"
  32 #include "llvm/Support/PrettyStackTrace.h"
  33 #include "llvm/Support/StandardPasses.h"
  34 #include "llvm/Support/SystemUtils.h"
  35 #include "llvm/Support/raw_ostream.h"
  36 #include "llvm/LinkAllPasses.h"
  37 #include "llvm/LinkAllVMCore.h"
  38 #include <memory>
  39 #include <algorithm>
  40 using namespace llvm;
  41
  42 // The OptimizationList is automatically populated with registered Passes by the
  43 // PassNameParser.
  44 //
  45 static cl::list<const PassInfo*, bool, PassNameParser>
  46 PassList(cl::desc("Optimizations available:"));
  47
  48 // Other command line options...
  49 //
  50 static cl::opt<std::string>
  51 InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
  52     cl::init("-"), cl::value_desc("filename"));
  53
  54 static cl::opt<std::string>
  55 OutputFilename("o", cl::desc("Override output filename"),
  56                cl::value_desc("filename"), cl::init("-"));
  57
  58 static cl::opt<bool>
  59 Force("f", cl::desc("Enable binary output on terminals"));
  60
  61 static cl::opt<bool>
  62 PrintEachXForm("p", cl::desc("Print module after each transformation"));
  63
  64 static cl::opt<bool>
  65 NoOutput("disable-output",
  66          cl::desc("Do not write result bitcode file"), cl::Hidden);
  67
  68 static cl::opt<bool>
  69 OutputAssembly("S", cl::desc("Write output as LLVM assembly"));
  70
  71 static cl::opt<bool>
  72 NoVerify("disable-verify", cl::desc("Do not verify result module"), cl::Hidden);
  73
  74 static cl::opt<bool>
  75 VerifyEach("verify-each", cl::desc("Verify after each transform"));
  76
  77 static cl::opt<bool>
  78 StripDebug("strip-debug",
  79            cl::desc("Strip debugger symbol info from translation unit"));
  80
  81 static cl::opt<bool>
  82 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
  83
  84 static cl::opt<bool>
  85 DisableOptimizations("disable-opt",
  86                      cl::desc("Do not run any optimization passes"));
  87
  88 static cl::opt<bool>
  89 DisableInternalize("disable-internalize",
  90                    cl::desc("Do not mark all symbols as internal"));
  91
  92 static cl::opt<bool>
  93 StandardCompileOpts("std-compile-opts",
  94                    cl::desc("Include the standard compile time optimizations"));
  95
  96 static cl::opt<bool>
  97 StandardLinkOpts("std-link-opts",
  98                  cl::desc("Include the standard link time optimizations"));
  99
 100 static cl::opt<bool>
 101 OptLevelO1("O1",
 102            cl::desc("Optimization level 1. Similar to llvm-gcc -O1"));
 103
 104 static cl::opt<bool>
 105 OptLevelO2("O2",
 106            cl::desc("Optimization level 2. Similar to llvm-gcc -O2"));
 107
 108 static cl::opt<bool>
 109 OptLevelO3("O3",
 110            cl::desc("Optimization level 3. Similar to llvm-gcc -O3"));
 111
 112 static cl::opt<bool>
 113 UnitAtATime("funit-at-a-time",
 114             cl::desc("Enable IPO. This is same as llvm-gcc's -funit-at-a-time"),
 115             cl::init(true));
 116
 117 static cl::opt<bool>
 118 DisableSimplifyLibCalls("disable-simplify-libcalls",
 119                         cl::desc("Disable simplify-libcalls"));
 120
 121 static cl::opt<bool>
 122 Quiet("q", cl::desc("Obsolete option"), cl::Hidden);
 123
 124 static cl::alias
 125 QuietA("quiet", cl::desc("Alias for -q"), cl::aliasopt(Quiet));
 126
 127 static cl::opt<bool>
 128 AnalyzeOnly("analyze", cl::desc("Only perform analysis, no optimization"));
 129
 130 static cl::opt<std::string>
 131 DefaultDataLayout("default-data-layout",
 132           cl::desc("data layout string to use if not specified by module"),
 133           cl::value_desc("layout-string"), cl::init(""));
 134
 135 // ---------- Define Printers for module and function passes ------------
 136 namespace {
 137
 138 struct CallGraphSCCPassPrinter : public CallGraphSCCPass {
 139   static char ID;
 140   const PassInfo *PassToPrint;
 141   CallGraphSCCPassPrinter(const PassInfo *PI) :
 142     CallGraphSCCPass(&ID), PassToPrint(PI) {}
 143
 144   virtual bool runOnSCC(CallGraphSCC &SCC) {
 145     if (!Quiet) {
 146       outs() << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
 147
 148       for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
 149         Function *F = (*I)->getFunction();
 150         if (F)
 151           getAnalysisID<Pass>(PassToPrint).print(outs(), F->getParent());
 152       }
 153     }
 154     // Get and print pass...
 155     return false;
 156   }
 157
 158   virtual const char *getPassName() const { return "'Pass' Printer"; }
 159
 160   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 161     AU.addRequiredID(PassToPrint);
 162     AU.setPreservesAll();
 163   }
 164 };
 165
 166 char CallGraphSCCPassPrinter::ID = 0;
 167
 168 struct ModulePassPrinter : public ModulePass {
 169   static char ID;
 170   const PassInfo *PassToPrint;
 171   ModulePassPrinter(const PassInfo *PI) : ModulePass(&ID),
 172                                           PassToPrint(PI) {}
 173
 174   virtual bool runOnModule(Module &M) {
 175     if (!Quiet) {
 176       outs() << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
 177       getAnalysisID<Pass>(PassToPrint).print(outs(), &M);
 178     }
 179
 180     // Get and print pass...
 181     return false;
 182   }
 183
 184   virtual const char *getPassName() const { return "'Pass' Printer"; }
 185
 186   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 187     AU.addRequiredID(PassToPrint);
 188     AU.setPreservesAll();
 189   }
 190 };
 191
 192 char ModulePassPrinter::ID = 0;
 193 struct FunctionPassPrinter : public FunctionPass {
 194   const PassInfo *PassToPrint;
 195   static char ID;
 196   FunctionPassPrinter(const PassInfo *PI) : FunctionPass(&ID),
 197                                             PassToPrint(PI) {}
 198
 199   virtual bool runOnFunction(Function &F) {
 200     if (!Quiet) {
 201       outs() << "Printing analysis '" << PassToPrint->getPassName()
 202               << "' for function '" << F.getName() << "':\n";
 203     }
 204     // Get and print pass...
 205     getAnalysisID<Pass>(PassToPrint).print(outs(), F.getParent());
 206     return false;
 207   }
 208
 209   virtual const char *getPassName() const { return "FunctionPass Printer"; }
 210
 211   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 212     AU.addRequiredID(PassToPrint);
 213     AU.setPreservesAll();
 214   }
 215 };
 216
 217 char FunctionPassPrinter::ID = 0;
 218
 219 struct LoopPassPrinter : public LoopPass {
 220   static char ID;
 221   const PassInfo *PassToPrint;
 222   LoopPassPrinter(const PassInfo *PI) :
 223     LoopPass(&ID), PassToPrint(PI) {}
 224
 225   virtual bool runOnLoop(Loop *L, LPPassManager &LPM) {
 226     if (!Quiet) {
 227       outs() << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
 228       getAnalysisID<Pass>(PassToPrint).print(outs(),
 229                                   L->getHeader()->getParent()->getParent());
 230     }
 231     // Get and print pass...
 232     return false;
 233   }
 234
 235   virtual const char *getPassName() const { return "'Pass' Printer"; }
 236
 237   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 238     AU.addRequiredID(PassToPrint);
 239     AU.setPreservesAll();
 240   }
 241 };
 242
 243 char LoopPassPrinter::ID = 0;
 244
 245 struct BasicBlockPassPrinter : public BasicBlockPass {
 246   const PassInfo *PassToPrint;
 247   static char ID;
 248   BasicBlockPassPrinter(const PassInfo *PI)
 249     : BasicBlockPass(&ID), PassToPrint(PI) {}
 250
 251   virtual bool runOnBasicBlock(BasicBlock &BB) {
 252     if (!Quiet) {
 253       outs() << "Printing Analysis info for BasicBlock '" << BB.getName()
 254              << "': Pass " << PassToPrint->getPassName() << ":\n";
 255     }
 256
 257     // Get and print pass...
 258     getAnalysisID<Pass>(PassToPrint).print(outs(), BB.getParent()->getParent());
 259     return false;
 260   }
 261
 262   virtual const char *getPassName() const { return "BasicBlockPass Printer"; }
 263
 264   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 265     AU.addRequiredID(PassToPrint);
 266     AU.setPreservesAll();
 267   }
 268 };
 269
 270 char BasicBlockPassPrinter::ID = 0;
 271 inline void addPass(PassManagerBase &PM, Pass *P) {
 272   // Add the pass to the pass manager...
 273   PM.add(P);
 274
 275   // If we are verifying all of the intermediate steps, add the verifier...
 276   if (VerifyEach) PM.add(createVerifierPass());
 277 }
 278
 279 /// AddOptimizationPasses - This routine adds optimization passes
 280 /// based on selected optimization level, OptLevel. This routine
 281 /// duplicates llvm-gcc behaviour.
 282 ///
 283 /// OptLevel - Optimization Level
 284 void AddOptimizationPasses(PassManagerBase &MPM, PassManagerBase &FPM,
 285                            unsigned OptLevel) {
 286   createStandardFunctionPasses(&FPM, OptLevel);
 287
 288   llvm::Pass *InliningPass = 0;
 289   if (DisableInline) {
 290     // No inlining pass
 291   } else if (OptLevel) {
 292     unsigned Threshold = 200;
 293     if (OptLevel > 2)
 294       Threshold = 250;
 295     InliningPass = createFunctionInliningPass(Threshold);
 296   } else {
 297     InliningPass = createAlwaysInlinerPass();
 298   }
 299   createStandardModulePasses(&MPM, OptLevel,
 300                              /*OptimizeSize=*/ false,
 301                              UnitAtATime,
 302                              /*UnrollLoops=*/ OptLevel > 1,
 303                              !DisableSimplifyLibCalls,
 304                              /*HaveExceptions=*/ true,
 305                              InliningPass);
 306 }
 307
 308 void AddStandardCompilePasses(PassManagerBase &PM) {
 309   PM.add(createVerifierPass());                  // Verify that input is correct
 310
 311   addPass(PM, createLowerSetJmpPass());          // Lower llvm.setjmp/.longjmp
 312
 313   // If the -strip-debug command line option was specified, do it.
 314   if (StripDebug)
 315     addPass(PM, createStripSymbolsPass(true));
 316
 317   if (DisableOptimizations) return;
 318
 319   llvm::Pass *InliningPass = !DisableInline ? createFunctionInliningPass() : 0;
 320
 321   // -std-compile-opts adds the same module passes as -O3.
 322   createStandardModulePasses(&PM, 3,
 323                              /*OptimizeSize=*/ false,
 324                              /*UnitAtATime=*/ true,
 325                              /*UnrollLoops=*/ true,
 326                              /*SimplifyLibCalls=*/ true,
 327                              /*HaveExceptions=*/ true,
 328                              InliningPass);
 329 }
 330
 331 void AddStandardLinkPasses(PassManagerBase &PM) {
 332   PM.add(createVerifierPass());                  // Verify that input is correct
 333
 334   // If the -strip-debug command line option was specified, do it.
 335   if (StripDebug)
 336     addPass(PM, createStripSymbolsPass(true));
 337
 338   if (DisableOptimizations) return;
 339
 340   createStandardLTOPasses(&PM, /*Internalize=*/ !DisableInternalize,
 341                           /*RunInliner=*/ !DisableInline,
 342                           /*VerifyEach=*/ VerifyEach);
 343 }
 344
 345 } // anonymous namespace
 346
 347
 348 //===----------------------------------------------------------------------===//
 349 // main for opt
 350 //
 351 int main(int argc, char **argv) {
 352   sys::PrintStackTraceOnErrorSignal();
 353   llvm::PrettyStackTraceProgram X(argc, argv);
 354
 355   // Enable debug stream buffering.
 356   EnableDebugBuffering = true;
 357
 358   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 359   LLVMContext &Context = getGlobalContext();
 360
 361   cl::ParseCommandLineOptions(argc, argv,
 362     "llvm .bc -> .bc modular optimizer and analysis printer\n");
 363
 364   // Allocate a full target machine description only if necessary.
 365   // FIXME: The choice of target should be controllable on the command line.
 366   std::auto_ptr<TargetMachine> target;
 367
 368   SMDiagnostic Err;
 369
 370   // Load the input module...
 371   std::auto_ptr<Module> M;
 372   M.reset(ParseIRFile(InputFilename, Err, Context));
 373
 374   if (M.get() == 0) {
 375     Err.Print(argv[0], errs());
 376     return 1;
 377   }
 378
 379   // Figure out what stream we are supposed to write to...
 380   raw_ostream *Out = 0;
 381   bool DeleteStream = false;
 382   if (!NoOutput && !AnalyzeOnly) {
 383     if (OutputFilename == "-") {
 384       // Print to stdout.
 385       Out = &outs();
 386       // If we're printing a bitcode file, switch stdout to binary mode.
 387       // FIXME: This switches outs() globally, not just for the bitcode output.
 388       if (!OutputAssembly)
 389         sys::Program::ChangeStdoutToBinary();
 390     } else {
 391       if (NoOutput || AnalyzeOnly) {
 392         errs() << "WARNING: The -o (output filename) option is ignored when\n"
 393                   "the --disable-output or --analyze options are used.\n";
 394       } else {
 395         // Make sure that the Output file gets unlinked from the disk if we get
 396         // a SIGINT.
 397         sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 398
 399         std::string ErrorInfo;
 400         Out = new raw_fd_ostream(OutputFilename.c_str(), ErrorInfo,
 401                                  raw_fd_ostream::F_Binary);
 402         if (!ErrorInfo.empty()) {
 403           errs() << ErrorInfo << '\n';
 404           delete Out;
 405           return 1;
 406         }
 407         DeleteStream = true;
 408       }
 409     }
 410   }
 411
 412   // If the output is set to be emitted to standard out, and standard out is a
 413   // console, print out a warning message and refuse to do it.  We don't
 414   // impress anyone by spewing tons of binary goo to a terminal.
 415   if (!Force && !NoOutput && !AnalyzeOnly && !OutputAssembly)
 416     if (CheckBitcodeOutputToConsole(*Out, !Quiet))
 417       NoOutput = true;
 418
 419   // Create a PassManager to hold and optimize the collection of passes we are
 420   // about to build...
 421   //
 422   PassManager Passes;
 423
 424   // Add an appropriate TargetData instance for this module...
 425   TargetData *TD = 0;
 426   const std::string &ModuleDataLayout = M.get()->getDataLayout();
 427   if (!ModuleDataLayout.empty())
 428     TD = new TargetData(ModuleDataLayout);
 429   else if (!DefaultDataLayout.empty())
 430     TD = new TargetData(DefaultDataLayout);
 431
 432   if (TD)
 433     Passes.add(TD);
 434
 435   OwningPtr<PassManager> FPasses;
 436   if (OptLevelO1 || OptLevelO2 || OptLevelO3) {
 437     FPasses.reset(new PassManager());
 438     if (TD)
 439       FPasses->add(new TargetData(*TD));
 440   }
 441
 442   // If the -strip-debug command line option was specified, add it.  If
 443   // -std-compile-opts was also specified, it will handle StripDebug.
 444   if (StripDebug && !StandardCompileOpts)
 445     addPass(Passes, createStripSymbolsPass(true));
 446
 447   // Create a new optimization pass for each one specified on the command line
 448   for (unsigned i = 0; i < PassList.size(); ++i) {
 449     // Check to see if -std-compile-opts was specified before this option.  If
 450     // so, handle it.
 451     if (StandardCompileOpts &&
 452         StandardCompileOpts.getPosition() < PassList.getPosition(i)) {
 453       AddStandardCompilePasses(Passes);
 454       StandardCompileOpts = false;
 455     }
 456
 457     if (StandardLinkOpts &&
 458         StandardLinkOpts.getPosition() < PassList.getPosition(i)) {
 459       AddStandardLinkPasses(Passes);
 460       StandardLinkOpts = false;
 461     }
 462
 463     if (OptLevelO1 && OptLevelO1.getPosition() < PassList.getPosition(i)) {
 464       AddOptimizationPasses(Passes, *FPasses, 1);
 465       OptLevelO1 = false;
 466     }
 467
 468     if (OptLevelO2 && OptLevelO2.getPosition() < PassList.getPosition(i)) {
 469       AddOptimizationPasses(Passes, *FPasses, 2);
 470       OptLevelO2 = false;
 471     }
 472
 473     if (OptLevelO3 && OptLevelO3.getPosition() < PassList.getPosition(i)) {
 474       AddOptimizationPasses(Passes, *FPasses, 3);
 475       OptLevelO3 = false;
 476     }
 477
 478     const PassInfo *PassInf = PassList[i];
 479     Pass *P = 0;
 480     if (PassInf->getNormalCtor())
 481       P = PassInf->getNormalCtor()();
 482     else
 483       errs() << argv[0] << ": cannot create pass: "
 484              << PassInf->getPassName() << "\n";
 485     if (P) {
 486       PassKind Kind = P->getPassKind();
 487       addPass(Passes, P);
 488
 489       if (AnalyzeOnly) {
 490         switch (Kind) {
 491         case PT_BasicBlock:
 492           Passes.add(new BasicBlockPassPrinter(PassInf));
 493           break;
 494         case PT_Loop:
 495           Passes.add(new LoopPassPrinter(PassInf));
 496           break;
 497         case PT_Function:
 498           Passes.add(new FunctionPassPrinter(PassInf));
 499           break;
 500         case PT_CallGraphSCC:
 501           Passes.add(new CallGraphSCCPassPrinter(PassInf));
 502           break;
 503         default:
 504           Passes.add(new ModulePassPrinter(PassInf));
 505           break;
 506         }
 507       }
 508     }
 509
 510     if (PrintEachXForm)
 511       Passes.add(createPrintModulePass(&errs()));
 512   }
 513
 514   // If -std-compile-opts was specified at the end of the pass list, add them.
 515   if (StandardCompileOpts) {
 516     AddStandardCompilePasses(Passes);
 517     StandardCompileOpts = false;
 518   }
 519
 520   if (StandardLinkOpts) {
 521     AddStandardLinkPasses(Passes);
 522     StandardLinkOpts = false;
 523   }
 524
 525   if (OptLevelO1)
 526     AddOptimizationPasses(Passes, *FPasses, 1);
 527
 528   if (OptLevelO2)
 529     AddOptimizationPasses(Passes, *FPasses, 2);
 530
 531   if (OptLevelO3)
 532     AddOptimizationPasses(Passes, *FPasses, 3);
 533
 534   if (OptLevelO1 || OptLevelO2 || OptLevelO3)
 535     FPasses->run(*M.get());
 536
 537   // Check that the module is well formed on completion of optimization
 538   if (!NoVerify && !VerifyEach)
 539     Passes.add(createVerifierPass());
 540
 541   // Write bitcode or assembly out to disk or outs() as the last step...
 542   if (!NoOutput && !AnalyzeOnly) {
 543     if (OutputAssembly)
 544       Passes.add(createPrintModulePass(Out));
 545     else
 546       Passes.add(createBitcodeWriterPass(*Out));
 547   }
 548
 549   // Now that we have all of the passes ready, run them.
 550   Passes.run(*M.get());
 551
 552   // Delete the raw_fd_ostream.
 553   if (DeleteStream)
 554     delete Out;
 555   return 0;
 556 }