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", 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(std::vector<CallGraphNode *>&SCC) {
 145     if (!Quiet) {
 146       outs() << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
 147
 148       for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
 149         Function *F = SCC[i]->getFunction();
 150         if (F) {
 151           getAnalysisID<Pass>(PassToPrint).print(outs(), F->getParent());
 152         }
 153       }
 154     }
 155     // Get and print pass...
 156     return false;
 157   }
 158
 159   virtual const char *getPassName() const { return "'Pass' Printer"; }
 160
 161   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 162     AU.addRequiredID(PassToPrint);
 163     AU.setPreservesAll();
 164   }
 165 };
 166
 167 char CallGraphSCCPassPrinter::ID = 0;
 168
 169 struct ModulePassPrinter : public ModulePass {
 170   static char ID;
 171   const PassInfo *PassToPrint;
 172   ModulePassPrinter(const PassInfo *PI) : ModulePass(&ID),
 173                                           PassToPrint(PI) {}
 174
 175   virtual bool runOnModule(Module &M) {
 176     if (!Quiet) {
 177       outs() << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
 178       getAnalysisID<Pass>(PassToPrint).print(outs(), &M);
 179     }
 180
 181     // Get and print pass...
 182     return false;
 183   }
 184
 185   virtual const char *getPassName() const { return "'Pass' Printer"; }
 186
 187   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 188     AU.addRequiredID(PassToPrint);
 189     AU.setPreservesAll();
 190   }
 191 };
 192
 193 char ModulePassPrinter::ID = 0;
 194 struct FunctionPassPrinter : public FunctionPass {
 195   const PassInfo *PassToPrint;
 196   static char ID;
 197   FunctionPassPrinter(const PassInfo *PI) : FunctionPass(&ID),
 198                                             PassToPrint(PI) {}
 199
 200   virtual bool runOnFunction(Function &F) {
 201     if (!Quiet) {
 202       outs() << "Printing analysis '" << PassToPrint->getPassName()
 203               << "' for function '" << F.getName() << "':\n";
 204     }
 205     // Get and print pass...
 206     getAnalysisID<Pass>(PassToPrint).print(outs(), F.getParent());
 207     return false;
 208   }
 209
 210   virtual const char *getPassName() const { return "FunctionPass Printer"; }
 211
 212   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 213     AU.addRequiredID(PassToPrint);
 214     AU.setPreservesAll();
 215   }
 216 };
 217
 218 char FunctionPassPrinter::ID = 0;
 219
 220 struct LoopPassPrinter : public LoopPass {
 221   static char ID;
 222   const PassInfo *PassToPrint;
 223   LoopPassPrinter(const PassInfo *PI) :
 224     LoopPass(&ID), PassToPrint(PI) {}
 225
 226   virtual bool runOnLoop(Loop *L, LPPassManager &LPM) {
 227     if (!Quiet) {
 228       outs() << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
 229       getAnalysisID<Pass>(PassToPrint).print(outs(),
 230                                   L->getHeader()->getParent()->getParent());
 231     }
 232     // Get and print pass...
 233     return false;
 234   }
 235
 236   virtual const char *getPassName() const { return "'Pass' Printer"; }
 237
 238   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
 239     AU.addRequiredID(PassToPrint);
 240     AU.setPreservesAll();
 241   }
 242 };
 243
 244 char LoopPassPrinter::ID = 0;
 245
 246 struct BasicBlockPassPrinter : public BasicBlockPass {
 247   const PassInfo *PassToPrint;
 248   static char ID;
 249   BasicBlockPassPrinter(const PassInfo *PI)
 250     : BasicBlockPass(&ID), PassToPrint(PI) {}
 251
 252   virtual bool runOnBasicBlock(BasicBlock &BB) {
 253     if (!Quiet) {
 254       outs() << "Printing Analysis info for BasicBlock '" << BB.getName()
 255              << "': Pass " << PassToPrint->getPassName() << ":\n";
 256     }
 257
 258     // Get and print pass...
 259     getAnalysisID<Pass>(PassToPrint).print(outs(), BB.getParent()->getParent());
 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
 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   SMDiagnostic Err;
 355
 356   // Load the input module...
 357   std::auto_ptr<Module> M;
 358   M.reset(ParseIRFile(InputFilename, Err, Context));
 359
 360   if (M.get() == 0) {
 361     Err.Print(argv[0], errs());
 362     return 1;
 363   }
 364
 365   // Figure out what stream we are supposed to write to...
 366   // FIXME: outs() is not binary!
 367   raw_ostream *Out = &outs();  // Default to printing to stdout...
 368   if (OutputFilename != "-") {
 369     // Make sure that the Output file gets unlinked from the disk if we get a
 370     // SIGINT
 371     sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 372
 373     std::string ErrorInfo;
 374     Out = new raw_fd_ostream(OutputFilename.c_str(), ErrorInfo,
 375                              raw_fd_ostream::F_Binary);
 376     if (!ErrorInfo.empty()) {
 377       errs() << ErrorInfo << '\n';
 378       delete Out;
 379       return 1;
 380     }
 381   }
 382
 383   // If the output is set to be emitted to standard out, and standard out is a
 384   // console, print out a warning message and refuse to do it.  We don't
 385   // impress anyone by spewing tons of binary goo to a terminal.
 386   if (!Force && !NoOutput && !OutputAssembly)
 387     if (CheckBitcodeOutputToConsole(*Out, !Quiet))
 388       NoOutput = true;
 389
 390   // Create a PassManager to hold and optimize the collection of passes we are
 391   // about to build...
 392   //
 393   PassManager Passes;
 394
 395   // Add an appropriate TargetData instance for this module...
 396   TargetData *TD = 0;
 397   const std::string &ModuleDataLayout = M.get()->getDataLayout();
 398   if (!ModuleDataLayout.empty())
 399     TD = new TargetData(ModuleDataLayout);
 400   else if (!DefaultDataLayout.empty())
 401     TD = new TargetData(DefaultDataLayout);
 402
 403   if (TD)
 404     Passes.add(TD);
 405
 406   FunctionPassManager *FPasses = NULL;
 407   if (OptLevelO1 || OptLevelO2 || OptLevelO3) {
 408     FPasses = new FunctionPassManager(new ExistingModuleProvider(M.get()));
 409     if (TD)
 410       FPasses->add(new TargetData(*TD));
 411   }
 412
 413   // If the -strip-debug command line option was specified, add it.  If
 414   // -std-compile-opts was also specified, it will handle StripDebug.
 415   if (StripDebug && !StandardCompileOpts)
 416     addPass(Passes, createStripSymbolsPass(true));
 417
 418   // Create a new optimization pass for each one specified on the command line
 419   for (unsigned i = 0; i < PassList.size(); ++i) {
 420     // Check to see if -std-compile-opts was specified before this option.  If
 421     // so, handle it.
 422     if (StandardCompileOpts &&
 423         StandardCompileOpts.getPosition() < PassList.getPosition(i)) {
 424       AddStandardCompilePasses(Passes);
 425       StandardCompileOpts = false;
 426     }
 427
 428     if (StandardLinkOpts &&
 429         StandardLinkOpts.getPosition() < PassList.getPosition(i)) {
 430       AddStandardLinkPasses(Passes);
 431       StandardLinkOpts = false;
 432     }
 433
 434     if (OptLevelO1 && OptLevelO1.getPosition() < PassList.getPosition(i)) {
 435       AddOptimizationPasses(Passes, *FPasses, 1);
 436       OptLevelO1 = false;
 437     }
 438
 439     if (OptLevelO2 && OptLevelO2.getPosition() < PassList.getPosition(i)) {
 440       AddOptimizationPasses(Passes, *FPasses, 2);
 441       OptLevelO2 = false;
 442     }
 443
 444     if (OptLevelO3 && OptLevelO3.getPosition() < PassList.getPosition(i)) {
 445       AddOptimizationPasses(Passes, *FPasses, 3);
 446       OptLevelO3 = false;
 447     }
 448
 449     const PassInfo *PassInf = PassList[i];
 450     Pass *P = 0;
 451     if (PassInf->getNormalCtor())
 452       P = PassInf->getNormalCtor()();
 453     else
 454       errs() << argv[0] << ": cannot create pass: "
 455              << PassInf->getPassName() << "\n";
 456     if (P) {
 457       bool isBBPass = dynamic_cast<BasicBlockPass*>(P) != 0;
 458       bool isLPass = !isBBPass && dynamic_cast<LoopPass*>(P) != 0;
 459       bool isFPass = !isLPass && dynamic_cast<FunctionPass*>(P) != 0;
 460       bool isCGSCCPass = !isFPass && dynamic_cast<CallGraphSCCPass*>(P) != 0;
 461
 462       addPass(Passes, P);
 463
 464       if (AnalyzeOnly) {
 465         if (isBBPass)
 466           Passes.add(new BasicBlockPassPrinter(PassInf));
 467         else if (isLPass)
 468           Passes.add(new LoopPassPrinter(PassInf));
 469         else if (isFPass)
 470           Passes.add(new FunctionPassPrinter(PassInf));
 471         else if (isCGSCCPass)
 472           Passes.add(new CallGraphSCCPassPrinter(PassInf));
 473         else
 474           Passes.add(new ModulePassPrinter(PassInf));
 475       }
 476     }
 477
 478     if (PrintEachXForm)
 479       Passes.add(createPrintModulePass(&errs()));
 480   }
 481
 482   // If -std-compile-opts was specified at the end of the pass list, add them.
 483   if (StandardCompileOpts) {
 484     AddStandardCompilePasses(Passes);
 485     StandardCompileOpts = false;
 486   }
 487
 488   if (StandardLinkOpts) {
 489     AddStandardLinkPasses(Passes);
 490     StandardLinkOpts = false;
 491   }
 492
 493   if (OptLevelO1)
 494     AddOptimizationPasses(Passes, *FPasses, 1);
 495
 496   if (OptLevelO2)
 497     AddOptimizationPasses(Passes, *FPasses, 2);
 498
 499   if (OptLevelO3)
 500     AddOptimizationPasses(Passes, *FPasses, 3);
 501
 502   if (OptLevelO1 || OptLevelO2 || OptLevelO3) {
 503     FPasses->doInitialization();
 504     for (Module::iterator I = M.get()->begin(), E = M.get()->end();
 505          I != E; ++I)
 506       FPasses->run(*I);
 507   }
 508
 509   // Check that the module is well formed on completion of optimization
 510   if (!NoVerify && !VerifyEach)
 511     Passes.add(createVerifierPass());
 512
 513   // Write bitcode or assembly  out to disk or outs() as the last step...
 514   if (!NoOutput && !AnalyzeOnly) {
 515     if (OutputAssembly)
 516       Passes.add(createPrintModulePass(Out));
 517     else
 518       Passes.add(createBitcodeWriterPass(*Out));
 519   }
 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 }