xref: /llvm-project-15.0.7/llvm/tools/opt/opt.cpp (revision 07748203) 
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/Streams.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 <iostream>
39 #include <fstream>
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("Overwrite output files"));
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 NoVerify("disable-verify", cl::desc("Do not verify result module"), cl::Hidden);
72 
73 static cl::opt<bool>
74 VerifyEach("verify-each", cl::desc("Verify after each transform"));
75 
76 static cl::opt<bool>
77 StripDebug("strip-debug",
78            cl::desc("Strip debugger symbol info from translation unit"));
79 
80 static cl::opt<bool>
81 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
82 
83 static cl::opt<bool>
84 DisableOptimizations("disable-opt",
85                      cl::desc("Do not run any optimization passes"));
86 
87 static cl::opt<bool>
88 StandardCompileOpts("std-compile-opts",
89                    cl::desc("Include the standard compile time optimizations"));
90 
91 static cl::opt<bool>
92 OptLevelO1("O1",
93            cl::desc("Optimization level 1. Similar to llvm-gcc -O1"));
94 
95 static cl::opt<bool>
96 OptLevelO2("O2",
97            cl::desc("Optimization level 2. Similar to llvm-gcc -O2"));
98 
99 static cl::opt<bool>
100 OptLevelO3("O3",
101            cl::desc("Optimization level 3. Similar to llvm-gcc -O3"));
102 
103 static cl::opt<bool>
104 UnitAtATime("funit-at-a-time",
105             cl::desc("Enable IPO. This is same as llvm-gcc's -funit-at-a-time"));
106 
107 static cl::opt<bool>
108 DisableSimplifyLibCalls("disable-simplify-libcalls",
109                         cl::desc("Disable simplify-libcalls"));
110 
111 static cl::opt<bool>
112 Quiet("q", cl::desc("Obsolete option"), cl::Hidden);
113 
114 static cl::alias
115 QuietA("quiet", cl::desc("Alias for -q"), cl::aliasopt(Quiet));
116 
117 static cl::opt<bool>
118 AnalyzeOnly("analyze", cl::desc("Only perform analysis, no optimization"));
119 
120 // ---------- Define Printers for module and function passes ------------
121 namespace {
122 
123 struct CallGraphSCCPassPrinter : public CallGraphSCCPass {
124   static char ID;
125   const PassInfo *PassToPrint;
126   CallGraphSCCPassPrinter(const PassInfo *PI) :
127     CallGraphSCCPass(&ID), PassToPrint(PI) {}
128 
129   virtual bool runOnSCC(const std::vector<CallGraphNode *>&SCC) {
130     if (!Quiet) {
131       cout << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
132 
133       for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
134         Function *F = SCC[i]->getFunction();
135         if (F)
136           getAnalysisID<Pass>(PassToPrint).print(cout, F->getParent());
137       }
138     }
139     // Get and print pass...
140     return false;
141   }
142 
143   virtual const char *getPassName() const { return "'Pass' Printer"; }
144 
145   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
146     AU.addRequiredID(PassToPrint);
147     AU.setPreservesAll();
148   }
149 };
150 
151 char CallGraphSCCPassPrinter::ID = 0;
152 
153 struct ModulePassPrinter : public ModulePass {
154   static char ID;
155   const PassInfo *PassToPrint;
156   ModulePassPrinter(const PassInfo *PI) : ModulePass(&ID),
157                                           PassToPrint(PI) {}
158 
159   virtual bool runOnModule(Module &M) {
160     if (!Quiet) {
161       cout << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
162       getAnalysisID<Pass>(PassToPrint).print(cout, &M);
163     }
164 
165     // Get and print pass...
166     return false;
167   }
168 
169   virtual const char *getPassName() const { return "'Pass' Printer"; }
170 
171   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
172     AU.addRequiredID(PassToPrint);
173     AU.setPreservesAll();
174   }
175 };
176 
177 char ModulePassPrinter::ID = 0;
178 struct FunctionPassPrinter : public FunctionPass {
179   const PassInfo *PassToPrint;
180   static char ID;
181   FunctionPassPrinter(const PassInfo *PI) : FunctionPass(&ID),
182                                             PassToPrint(PI) {}
183 
184   virtual bool runOnFunction(Function &F) {
185     if (!Quiet) {
186       cout << "Printing analysis '" << PassToPrint->getPassName()
187            << "' for function '" << F.getName() << "':\n";
188     }
189     // Get and print pass...
190     getAnalysisID<Pass>(PassToPrint).print(cout, F.getParent());
191     return false;
192   }
193 
194   virtual const char *getPassName() const { return "FunctionPass Printer"; }
195 
196   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
197     AU.addRequiredID(PassToPrint);
198     AU.setPreservesAll();
199   }
200 };
201 
202 char FunctionPassPrinter::ID = 0;
203 
204 struct LoopPassPrinter : public LoopPass {
205   static char ID;
206   const PassInfo *PassToPrint;
207   LoopPassPrinter(const PassInfo *PI) :
208     LoopPass(&ID), PassToPrint(PI) {}
209 
210   virtual bool runOnLoop(Loop *L, LPPassManager &LPM) {
211     if (!Quiet) {
212       cout << "Printing analysis '" << PassToPrint->getPassName() << "':\n";
213       getAnalysisID<Pass>(PassToPrint).print(cout,
214                                   L->getHeader()->getParent()->getParent());
215     }
216     // Get and print pass...
217     return false;
218   }
219 
220   virtual const char *getPassName() const { return "'Pass' Printer"; }
221 
222   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
223     AU.addRequiredID(PassToPrint);
224     AU.setPreservesAll();
225   }
226 };
227 
228 char LoopPassPrinter::ID = 0;
229 
230 struct BasicBlockPassPrinter : public BasicBlockPass {
231   const PassInfo *PassToPrint;
232   static char ID;
233   BasicBlockPassPrinter(const PassInfo *PI)
234     : BasicBlockPass(&ID), PassToPrint(PI) {}
235 
236   virtual bool runOnBasicBlock(BasicBlock &BB) {
237     if (!Quiet) {
238       cout << "Printing Analysis info for BasicBlock '" << BB.getName()
239            << "': Pass " << PassToPrint->getPassName() << ":\n";
240     }
241 
242     // Get and print pass...
243     getAnalysisID<Pass>(PassToPrint).print(cout, BB.getParent()->getParent());
244     return false;
245   }
246 
247   virtual const char *getPassName() const { return "BasicBlockPass Printer"; }
248 
249   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
250     AU.addRequiredID(PassToPrint);
251     AU.setPreservesAll();
252   }
253 };
254 
255 char BasicBlockPassPrinter::ID = 0;
256 inline void addPass(PassManager &PM, Pass *P) {
257   // Add the pass to the pass manager...
258   PM.add(P);
259 
260   // If we are verifying all of the intermediate steps, add the verifier...
261   if (VerifyEach) PM.add(createVerifierPass());
262 }
263 
264 /// AddOptimizationPasses - This routine adds optimization passes
265 /// based on selected optimization level, OptLevel. This routine
266 /// duplicates llvm-gcc behaviour.
267 ///
268 /// OptLevel - Optimization Level
269 void AddOptimizationPasses(PassManager &MPM, FunctionPassManager &FPM,
270                            unsigned OptLevel) {
271   createStandardFunctionPasses(&FPM, OptLevel);
272 
273   llvm::Pass *InliningPass = OptLevel > 1 ? createFunctionInliningPass() : 0;
274   createStandardModulePasses(&MPM, OptLevel,
275                              /*OptimizeSize=*/ false,
276                              UnitAtATime,
277                              /*UnrollLoops=*/ OptLevel > 1,
278                              !DisableSimplifyLibCalls,
279                              /*HaveExceptions=*/ true,
280                              InliningPass);
281 }
282 
283 void AddStandardCompilePasses(PassManager &PM) {
284   PM.add(createVerifierPass());                  // Verify that input is correct
285 
286   addPass(PM, createLowerSetJmpPass());          // Lower llvm.setjmp/.longjmp
287 
288   // If the -strip-debug command line option was specified, do it.
289   if (StripDebug)
290     addPass(PM, createStripSymbolsPass(true));
291 
292   if (DisableOptimizations) return;
293 
294   llvm::Pass *InliningPass = !DisableInline ? createFunctionInliningPass() : 0;
295 
296   // -std-compile-opts adds the same module passes as -O3.
297   createStandardModulePasses(&PM, 3,
298                              /*OptimizeSize=*/ false,
299                              /*UnitAtATime=*/ true,
300                              /*UnrollLoops=*/ true,
301                              /*SimplifyLibCalls=*/ true,
302                              /*HaveExceptions=*/ true,
303                              InliningPass);
304 }
305 
306 } // anonymous namespace
307 
308 
309 //===----------------------------------------------------------------------===//
310 // main for opt
311 //
312 int main(int argc, char **argv) {
313   llvm_shutdown_obj X;  // Call llvm_shutdown() on exit.
314   LLVMContext Context;
315   try {
316     cl::ParseCommandLineOptions(argc, argv,
317       "llvm .bc -> .bc modular optimizer and analysis printer\n");
318     sys::PrintStackTraceOnErrorSignal();
319 
320     // Allocate a full target machine description only if necessary.
321     // FIXME: The choice of target should be controllable on the command line.
322     std::auto_ptr<TargetMachine> target;
323 
324     std::string ErrorMessage;
325 
326     // Load the input module...
327     std::auto_ptr<Module> M;
328     if (MemoryBuffer *Buffer
329           = MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage)) {
330       M.reset(ParseBitcodeFile(Buffer, Context, &ErrorMessage));
331       delete Buffer;
332     }
333 
334     if (M.get() == 0) {
335       cerr << argv[0] << ": ";
336       if (ErrorMessage.size())
337         cerr << ErrorMessage << "\n";
338       else
339         cerr << "bitcode didn't read correctly.\n";
340       return 1;
341     }
342 
343     // Figure out what stream we are supposed to write to...
344     // FIXME: cout is not binary!
345     std::ostream *Out = &std::cout;  // Default to printing to stdout...
346     if (OutputFilename != "-") {
347       if (!Force && std::ifstream(OutputFilename.c_str())) {
348         // If force is not specified, make sure not to overwrite a file!
349         cerr << argv[0] << ": error opening '" << OutputFilename
350              << "': file exists!\n"
351              << "Use -f command line argument to force output\n";
352         return 1;
353       }
354       std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
355                                    std::ios::binary;
356       Out = new std::ofstream(OutputFilename.c_str(), io_mode);
357 
358       if (!Out->good()) {
359         cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
360         return 1;
361       }
362 
363       // Make sure that the Output file gets unlinked from the disk if we get a
364       // SIGINT
365       sys::RemoveFileOnSignal(sys::Path(OutputFilename));
366     }
367 
368     // If the output is set to be emitted to standard out, and standard out is a
369     // console, print out a warning message and refuse to do it.  We don't
370     // impress anyone by spewing tons of binary goo to a terminal.
371     if (!Force && !NoOutput && CheckBitcodeOutputToConsole(Out,!Quiet)) {
372       NoOutput = true;
373     }
374 
375     // Create a PassManager to hold and optimize the collection of passes we are
376     // about to build...
377     //
378     PassManager Passes;
379 
380     // Add an appropriate TargetData instance for this module...
381     Passes.add(new TargetData(M.get()));
382 
383     FunctionPassManager *FPasses = NULL;
384     if (OptLevelO1 || OptLevelO2 || OptLevelO3) {
385       FPasses = new FunctionPassManager(new ExistingModuleProvider(M.get()));
386       FPasses->add(new TargetData(M.get()));
387     }
388 
389     // If the -strip-debug command line option was specified, add it.  If
390     // -std-compile-opts was also specified, it will handle StripDebug.
391     if (StripDebug && !StandardCompileOpts)
392       addPass(Passes, createStripSymbolsPass(true));
393 
394     // Create a new optimization pass for each one specified on the command line
395     for (unsigned i = 0; i < PassList.size(); ++i) {
396       // Check to see if -std-compile-opts was specified before this option.  If
397       // so, handle it.
398       if (StandardCompileOpts &&
399           StandardCompileOpts.getPosition() < PassList.getPosition(i)) {
400         AddStandardCompilePasses(Passes);
401         StandardCompileOpts = false;
402       }
403 
404       if (OptLevelO1 && OptLevelO1.getPosition() < PassList.getPosition(i)) {
405         AddOptimizationPasses(Passes, *FPasses, 1);
406         OptLevelO1 = false;
407       }
408 
409       if (OptLevelO2 && OptLevelO2.getPosition() < PassList.getPosition(i)) {
410         AddOptimizationPasses(Passes, *FPasses, 2);
411         OptLevelO2 = false;
412       }
413 
414       if (OptLevelO3 && OptLevelO3.getPosition() < PassList.getPosition(i)) {
415         AddOptimizationPasses(Passes, *FPasses, 3);
416         OptLevelO3 = false;
417       }
418 
419       const PassInfo *PassInf = PassList[i];
420       Pass *P = 0;
421       if (PassInf->getNormalCtor())
422         P = PassInf->getNormalCtor()();
423       else
424         cerr << argv[0] << ": cannot create pass: "
425              << PassInf->getPassName() << "\n";
426       if (P) {
427         bool isBBPass = dynamic_cast<BasicBlockPass*>(P) != 0;
428         bool isLPass = !isBBPass && dynamic_cast<LoopPass*>(P) != 0;
429         bool isFPass = !isLPass && dynamic_cast<FunctionPass*>(P) != 0;
430         bool isCGSCCPass = !isFPass && dynamic_cast<CallGraphSCCPass*>(P) != 0;
431 
432         addPass(Passes, P);
433 
434         if (AnalyzeOnly) {
435           if (isBBPass)
436             Passes.add(new BasicBlockPassPrinter(PassInf));
437           else if (isLPass)
438             Passes.add(new LoopPassPrinter(PassInf));
439           else if (isFPass)
440             Passes.add(new FunctionPassPrinter(PassInf));
441           else if (isCGSCCPass)
442             Passes.add(new CallGraphSCCPassPrinter(PassInf));
443           else
444             Passes.add(new ModulePassPrinter(PassInf));
445         }
446       }
447 
448       if (PrintEachXForm)
449         Passes.add(createPrintModulePass(&errs()));
450     }
451 
452     // If -std-compile-opts was specified at the end of the pass list, add them.
453     if (StandardCompileOpts) {
454       AddStandardCompilePasses(Passes);
455       StandardCompileOpts = false;
456     }
457 
458     if (OptLevelO1) {
459         AddOptimizationPasses(Passes, *FPasses, 1);
460       }
461 
462     if (OptLevelO2) {
463         AddOptimizationPasses(Passes, *FPasses, 2);
464       }
465 
466     if (OptLevelO3) {
467         AddOptimizationPasses(Passes, *FPasses, 3);
468       }
469 
470     if (OptLevelO1 || OptLevelO2 || OptLevelO3) {
471       for (Module::iterator I = M.get()->begin(), E = M.get()->end();
472            I != E; ++I)
473         FPasses->run(*I);
474     }
475 
476     // Check that the module is well formed on completion of optimization
477     if (!NoVerify && !VerifyEach)
478       Passes.add(createVerifierPass());
479 
480     // Write bitcode out to disk or cout as the last step...
481     if (!NoOutput && !AnalyzeOnly)
482       Passes.add(CreateBitcodeWriterPass(*Out));
483 
484     // Now that we have all of the passes ready, run them.
485     Passes.run(*M.get());
486 
487     // Delete the ofstream.
488     if (Out != &std::cout)
489       delete Out;
490     return 0;
491 
492   } catch (const std::string& msg) {
493     cerr << argv[0] << ": " << msg << "\n";
494   } catch (...) {
495     cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
496   }
497   llvm_shutdown();
498   return 1;
499 }
500