xref: /llvm-project-15.0.7/llvm/tools/opt/opt.cpp (revision bbabd39c) 
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 }
537