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