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