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