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