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 "BreakpointPrinter.h"
16 #include "NewPMDriver.h"
17 #include "PassPrinters.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/Analysis/CallGraph.h"
20 #include "llvm/Analysis/CallGraphSCCPass.h"
21 #include "llvm/Analysis/LoopPass.h"
22 #include "llvm/Analysis/RegionPass.h"
23 #include "llvm/Bitcode/BitcodeWriterPass.h"
24 #include "llvm/CodeGen/CommandFlags.h"
25 #include "llvm/IR/DataLayout.h"
26 #include "llvm/IR/IRPrintingPasses.h"
27 #include "llvm/IR/LLVMContext.h"
28 #include "llvm/IR/LegacyPassNameParser.h"
29 #include "llvm/IR/Module.h"
30 #include "llvm/IR/Verifier.h"
31 #include "llvm/IRReader/IRReader.h"
32 #include "llvm/InitializePasses.h"
33 #include "llvm/LinkAllIR.h"
34 #include "llvm/LinkAllPasses.h"
35 #include "llvm/MC/SubtargetFeature.h"
36 #include "llvm/PassManager.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/FileSystem.h"
39 #include "llvm/Support/ManagedStatic.h"
40 #include "llvm/Support/PluginLoader.h"
41 #include "llvm/Support/PrettyStackTrace.h"
42 #include "llvm/Support/Signals.h"
43 #include "llvm/Support/SourceMgr.h"
44 #include "llvm/Support/SystemUtils.h"
45 #include "llvm/Support/TargetRegistry.h"
46 #include "llvm/Support/TargetSelect.h"
47 #include "llvm/Support/ToolOutputFile.h"
48 #include "llvm/Target/TargetLibraryInfo.h"
49 #include "llvm/Target/TargetMachine.h"
50 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
51 #include <algorithm>
52 #include <memory>
53 using namespace llvm;
54 using namespace opt_tool;
55
56 // The OptimizationList is automatically populated with registered Passes by the
57 // PassNameParser.
58 //
59 static cl::list<const PassInfo*, bool, PassNameParser>
60 PassList(cl::desc("Optimizations available:"));
61
62 // This flag specifies a textual description of the optimization pass pipeline
63 // to run over the module. This flag switches opt to use the new pass manager
64 // infrastructure, completely disabling all of the flags specific to the old
65 // pass management.
66 static cl::opt<std::string> PassPipeline(
67 "passes",
68 cl::desc("A textual description of the pass pipeline for optimizing"),
69 cl::Hidden);
70
71 // Other command line options...
72 //
73 static cl::opt<std::string>
74 InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
75 cl::init("-"), cl::value_desc("filename"));
76
77 static cl::opt<std::string>
78 OutputFilename("o", cl::desc("Override output filename"),
79 cl::value_desc("filename"));
80
81 static cl::opt<bool>
82 Force("f", cl::desc("Enable binary output on terminals"));
83
84 static cl::opt<bool>
85 PrintEachXForm("p", cl::desc("Print module after each transformation"));
86
87 static cl::opt<bool>
88 NoOutput("disable-output",
89 cl::desc("Do not write result bitcode file"), cl::Hidden);
90
91 static cl::opt<bool>
92 OutputAssembly("S", cl::desc("Write output as LLVM assembly"));
93
94 static cl::opt<bool>
95 NoVerify("disable-verify", cl::desc("Do not verify result module"), cl::Hidden);
96
97 static cl::opt<bool>
98 VerifyEach("verify-each", cl::desc("Verify after each transform"));
99
100 static cl::opt<bool>
101 StripDebug("strip-debug",
102 cl::desc("Strip debugger symbol info from translation unit"));
103
104 static cl::opt<bool>
105 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
106
107 static cl::opt<bool>
108 DisableOptimizations("disable-opt",
109 cl::desc("Do not run any optimization passes"));
110
111 static cl::opt<bool>
112 DisableInternalize("disable-internalize",
113 cl::desc("Do not mark all symbols as internal"));
114
115 static cl::opt<bool>
116 StandardCompileOpts("std-compile-opts",
117 cl::desc("Include the standard compile time optimizations"));
118
119 static cl::opt<bool>
120 StandardLinkOpts("std-link-opts",
121 cl::desc("Include the standard link time optimizations"));
122
123 static cl::opt<bool>
124 OptLevelO1("O1",
125 cl::desc("Optimization level 1. Similar to clang -O1"));
126
127 static cl::opt<bool>
128 OptLevelO2("O2",
129 cl::desc("Optimization level 2. Similar to clang -O2"));
130
131 static cl::opt<bool>
132 OptLevelOs("Os",
133 cl::desc("Like -O2 with extra optimizations for size. Similar to clang -Os"));
134
135 static cl::opt<bool>
136 OptLevelOz("Oz",
137 cl::desc("Like -Os but reduces code size further. Similar to clang -Oz"));
138
139 static cl::opt<bool>
140 OptLevelO3("O3",
141 cl::desc("Optimization level 3. Similar to clang -O3"));
142
143 static cl::opt<std::string>
144 TargetTriple("mtriple", cl::desc("Override target triple for module"));
145
146 static cl::opt<bool>
147 UnitAtATime("funit-at-a-time",
148 cl::desc("Enable IPO. This is same as llvm-gcc's -funit-at-a-time"),
149 cl::init(true));
150
151 static cl::opt<bool>
152 DisableLoopUnrolling("disable-loop-unrolling",
153 cl::desc("Disable loop unrolling in all relevant passes"),
154 cl::init(false));
155 static cl::opt<bool>
156 DisableLoopVectorization("disable-loop-vectorization",
157 cl::desc("Disable the loop vectorization pass"),
158 cl::init(false));
159
160 static cl::opt<bool>
161 DisableSLPVectorization("disable-slp-vectorization",
162 cl::desc("Disable the slp vectorization pass"),
163 cl::init(false));
164
165
166 static cl::opt<bool>
167 DisableSimplifyLibCalls("disable-simplify-libcalls",
168 cl::desc("Disable simplify-libcalls"));
169
170 static cl::opt<bool>
171 Quiet("q", cl::desc("Obsolete option"), cl::Hidden);
172
173 static cl::alias
174 QuietA("quiet", cl::desc("Alias for -q"), cl::aliasopt(Quiet));
175
176 static cl::opt<bool>
177 AnalyzeOnly("analyze", cl::desc("Only perform analysis, no optimization"));
178
179 static cl::opt<bool>
180 PrintBreakpoints("print-breakpoints-for-testing",
181 cl::desc("Print select breakpoints location for testing"));
182
183 static cl::opt<std::string>
184 DefaultDataLayout("default-data-layout",
185 cl::desc("data layout string to use if not specified by module"),
186 cl::value_desc("layout-string"), cl::init(""));
187
188
189
addPass(PassManagerBase & PM,Pass * P)190 static inline void addPass(PassManagerBase &PM, Pass *P) {
191 // Add the pass to the pass manager...
192 PM.add(P);
193
194 // If we are verifying all of the intermediate steps, add the verifier...
195 if (VerifyEach) {
196 PM.add(createVerifierPass());
197 PM.add(createDebugInfoVerifierPass());
198 }
199 }
200
201 /// AddOptimizationPasses - This routine adds optimization passes
202 /// based on selected optimization level, OptLevel. This routine
203 /// duplicates llvm-gcc behaviour.
204 ///
205 /// OptLevel - Optimization Level
AddOptimizationPasses(PassManagerBase & MPM,FunctionPassManager & FPM,unsigned OptLevel,unsigned SizeLevel)206 static void AddOptimizationPasses(PassManagerBase &MPM,FunctionPassManager &FPM,
207 unsigned OptLevel, unsigned SizeLevel) {
208 FPM.add(createVerifierPass()); // Verify that input is correct
209 MPM.add(createDebugInfoVerifierPass()); // Verify that debug info is correct
210
211 PassManagerBuilder Builder;
212 Builder.OptLevel = OptLevel;
213 Builder.SizeLevel = SizeLevel;
214
215 if (DisableInline) {
216 // No inlining pass
217 } else if (OptLevel > 1) {
218 Builder.Inliner = createFunctionInliningPass(OptLevel, SizeLevel);
219 } else {
220 Builder.Inliner = createAlwaysInlinerPass();
221 }
222 Builder.DisableUnitAtATime = !UnitAtATime;
223 Builder.DisableUnrollLoops = (DisableLoopUnrolling.getNumOccurrences() > 0) ?
224 DisableLoopUnrolling : OptLevel == 0;
225
226 // This is final, unless there is a #pragma vectorize enable
227 if (DisableLoopVectorization)
228 Builder.LoopVectorize = false;
229 // If option wasn't forced via cmd line (-vectorize-loops, -loop-vectorize)
230 else if (!Builder.LoopVectorize)
231 Builder.LoopVectorize = OptLevel > 1 && SizeLevel < 2;
232
233 // When #pragma vectorize is on for SLP, do the same as above
234 Builder.SLPVectorize =
235 DisableSLPVectorization ? false : OptLevel > 1 && SizeLevel < 2;
236
237 Builder.populateFunctionPassManager(FPM);
238 Builder.populateModulePassManager(MPM);
239 }
240
AddStandardCompilePasses(PassManagerBase & PM)241 static void AddStandardCompilePasses(PassManagerBase &PM) {
242 PM.add(createVerifierPass()); // Verify that input is correct
243
244 // If the -strip-debug command line option was specified, do it.
245 if (StripDebug)
246 addPass(PM, createStripSymbolsPass(true));
247
248 // Verify debug info only after it's (possibly) stripped.
249 PM.add(createDebugInfoVerifierPass());
250
251 if (DisableOptimizations) return;
252
253 // -std-compile-opts adds the same module passes as -O3.
254 PassManagerBuilder Builder;
255 if (!DisableInline)
256 Builder.Inliner = createFunctionInliningPass();
257 Builder.OptLevel = 3;
258 Builder.populateModulePassManager(PM);
259 }
260
AddStandardLinkPasses(PassManagerBase & PM)261 static void AddStandardLinkPasses(PassManagerBase &PM) {
262 PM.add(createVerifierPass()); // Verify that input is correct
263
264 // If the -strip-debug command line option was specified, do it.
265 if (StripDebug)
266 addPass(PM, createStripSymbolsPass(true));
267
268 // Verify debug info only after it's (possibly) stripped.
269 PM.add(createDebugInfoVerifierPass());
270
271 if (DisableOptimizations) return;
272
273 PassManagerBuilder Builder;
274 Builder.populateLTOPassManager(PM, /*Internalize=*/ !DisableInternalize,
275 /*RunInliner=*/ !DisableInline);
276 }
277
278 //===----------------------------------------------------------------------===//
279 // CodeGen-related helper functions.
280 //
281
GetCodeGenOptLevel()282 CodeGenOpt::Level GetCodeGenOptLevel() {
283 if (OptLevelO1)
284 return CodeGenOpt::Less;
285 if (OptLevelO2)
286 return CodeGenOpt::Default;
287 if (OptLevelO3)
288 return CodeGenOpt::Aggressive;
289 return CodeGenOpt::None;
290 }
291
292 // Returns the TargetMachine instance or zero if no triple is provided.
GetTargetMachine(Triple TheTriple)293 static TargetMachine* GetTargetMachine(Triple TheTriple) {
294 std::string Error;
295 const Target *TheTarget = TargetRegistry::lookupTarget(MArch, TheTriple,
296 Error);
297 // Some modules don't specify a triple, and this is okay.
298 if (!TheTarget) {
299 return nullptr;
300 }
301
302 // Package up features to be passed to target/subtarget
303 std::string FeaturesStr;
304 if (MAttrs.size()) {
305 SubtargetFeatures Features;
306 for (unsigned i = 0; i != MAttrs.size(); ++i)
307 Features.AddFeature(MAttrs[i]);
308 FeaturesStr = Features.getString();
309 }
310
311 return TheTarget->createTargetMachine(TheTriple.getTriple(),
312 MCPU, FeaturesStr,
313 InitTargetOptionsFromCodeGenFlags(),
314 RelocModel, CMModel,
315 GetCodeGenOptLevel());
316 }
317
318 #ifdef LINK_POLLY_INTO_TOOLS
319 namespace polly {
320 void initializePollyPasses(llvm::PassRegistry &Registry);
321 }
322 #endif
323
324 //===----------------------------------------------------------------------===//
325 // main for opt
326 //
main(int argc,char ** argv)327 int main(int argc, char **argv) {
328 sys::PrintStackTraceOnErrorSignal();
329 llvm::PrettyStackTraceProgram X(argc, argv);
330
331 // Enable debug stream buffering.
332 EnableDebugBuffering = true;
333
334 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
335 LLVMContext &Context = getGlobalContext();
336
337 InitializeAllTargets();
338 InitializeAllTargetMCs();
339 InitializeAllAsmPrinters();
340
341 // Initialize passes
342 PassRegistry &Registry = *PassRegistry::getPassRegistry();
343 initializeCore(Registry);
344 initializeDebugIRPass(Registry);
345 initializeScalarOpts(Registry);
346 initializeObjCARCOpts(Registry);
347 initializeVectorization(Registry);
348 initializeIPO(Registry);
349 initializeAnalysis(Registry);
350 initializeIPA(Registry);
351 initializeTransformUtils(Registry);
352 initializeInstCombine(Registry);
353 initializeInstrumentation(Registry);
354 initializeTarget(Registry);
355 // For codegen passes, only passes that do IR to IR transformation are
356 // supported.
357 initializeCodeGenPreparePass(Registry);
358 initializeAtomicExpandLoadLinkedPass(Registry);
359
360 #ifdef LINK_POLLY_INTO_TOOLS
361 polly::initializePollyPasses(Registry);
362 #endif
363
364 cl::ParseCommandLineOptions(argc, argv,
365 "llvm .bc -> .bc modular optimizer and analysis printer\n");
366
367 if (AnalyzeOnly && NoOutput) {
368 errs() << argv[0] << ": analyze mode conflicts with no-output mode.\n";
369 return 1;
370 }
371
372 SMDiagnostic Err;
373
374 // Load the input module...
375 std::unique_ptr<Module> M;
376 M.reset(ParseIRFile(InputFilename, Err, Context));
377
378 if (!M.get()) {
379 Err.print(argv[0], errs());
380 return 1;
381 }
382
383 // If we are supposed to override the target triple, do so now.
384 if (!TargetTriple.empty())
385 M->setTargetTriple(Triple::normalize(TargetTriple));
386
387 // Figure out what stream we are supposed to write to...
388 std::unique_ptr<tool_output_file> Out;
389 if (NoOutput) {
390 if (!OutputFilename.empty())
391 errs() << "WARNING: The -o (output filename) option is ignored when\n"
392 "the --disable-output option is used.\n";
393 } else {
394 // Default to standard output.
395 if (OutputFilename.empty())
396 OutputFilename = "-";
397
398 std::string ErrorInfo;
399 Out.reset(new tool_output_file(OutputFilename.c_str(), ErrorInfo,
400 sys::fs::F_None));
401 if (!ErrorInfo.empty()) {
402 errs() << ErrorInfo << '\n';
403 return 1;
404 }
405 }
406
407 // If the output is set to be emitted to standard out, and standard out is a
408 // console, print out a warning message and refuse to do it. We don't
409 // impress anyone by spewing tons of binary goo to a terminal.
410 if (!Force && !NoOutput && !AnalyzeOnly && !OutputAssembly)
411 if (CheckBitcodeOutputToConsole(Out->os(), !Quiet))
412 NoOutput = true;
413
414 if (PassPipeline.getNumOccurrences() > 0) {
415 OutputKind OK = OK_NoOutput;
416 if (!NoOutput)
417 OK = OutputAssembly ? OK_OutputAssembly : OK_OutputBitcode;
418
419 VerifierKind VK = VK_VerifyInAndOut;
420 if (NoVerify)
421 VK = VK_NoVerifier;
422 else if (VerifyEach)
423 VK = VK_VerifyEachPass;
424
425 // The user has asked to use the new pass manager and provided a pipeline
426 // string. Hand off the rest of the functionality to the new code for that
427 // layer.
428 return runPassPipeline(argv[0], Context, *M.get(), Out.get(), PassPipeline,
429 OK, VK)
430 ? 0
431 : 1;
432 }
433
434 // Create a PassManager to hold and optimize the collection of passes we are
435 // about to build.
436 //
437 PassManager Passes;
438
439 // Add an appropriate TargetLibraryInfo pass for the module's triple.
440 TargetLibraryInfo *TLI = new TargetLibraryInfo(Triple(M->getTargetTriple()));
441
442 // The -disable-simplify-libcalls flag actually disables all builtin optzns.
443 if (DisableSimplifyLibCalls)
444 TLI->disableAllFunctions();
445 Passes.add(TLI);
446
447 // Add an appropriate DataLayout instance for this module.
448 const DataLayout *DL = M.get()->getDataLayout();
449 if (!DL && !DefaultDataLayout.empty()) {
450 M->setDataLayout(DefaultDataLayout);
451 DL = M.get()->getDataLayout();
452 }
453
454 if (DL)
455 Passes.add(new DataLayoutPass(M.get()));
456
457 Triple ModuleTriple(M->getTargetTriple());
458 TargetMachine *Machine = nullptr;
459 if (ModuleTriple.getArch())
460 Machine = GetTargetMachine(Triple(ModuleTriple));
461 std::unique_ptr<TargetMachine> TM(Machine);
462
463 // Add internal analysis passes from the target machine.
464 if (TM.get())
465 TM->addAnalysisPasses(Passes);
466
467 std::unique_ptr<FunctionPassManager> FPasses;
468 if (OptLevelO1 || OptLevelO2 || OptLevelOs || OptLevelOz || OptLevelO3) {
469 FPasses.reset(new FunctionPassManager(M.get()));
470 if (DL)
471 FPasses->add(new DataLayoutPass(M.get()));
472 if (TM.get())
473 TM->addAnalysisPasses(*FPasses);
474
475 }
476
477 if (PrintBreakpoints) {
478 // Default to standard output.
479 if (!Out) {
480 if (OutputFilename.empty())
481 OutputFilename = "-";
482
483 std::string ErrorInfo;
484 Out.reset(new tool_output_file(OutputFilename.c_str(), ErrorInfo,
485 sys::fs::F_None));
486 if (!ErrorInfo.empty()) {
487 errs() << ErrorInfo << '\n';
488 return 1;
489 }
490 }
491 Passes.add(createBreakpointPrinter(Out->os()));
492 NoOutput = true;
493 }
494
495 // If the -strip-debug command line option was specified, add it. If
496 // -std-compile-opts was also specified, it will handle StripDebug.
497 if (StripDebug && !StandardCompileOpts)
498 addPass(Passes, createStripSymbolsPass(true));
499
500 // Create a new optimization pass for each one specified on the command line
501 for (unsigned i = 0; i < PassList.size(); ++i) {
502 // Check to see if -std-compile-opts was specified before this option. If
503 // so, handle it.
504 if (StandardCompileOpts &&
505 StandardCompileOpts.getPosition() < PassList.getPosition(i)) {
506 AddStandardCompilePasses(Passes);
507 StandardCompileOpts = false;
508 }
509
510 if (StandardLinkOpts &&
511 StandardLinkOpts.getPosition() < PassList.getPosition(i)) {
512 AddStandardLinkPasses(Passes);
513 StandardLinkOpts = false;
514 }
515
516 if (OptLevelO1 && OptLevelO1.getPosition() < PassList.getPosition(i)) {
517 AddOptimizationPasses(Passes, *FPasses, 1, 0);
518 OptLevelO1 = false;
519 }
520
521 if (OptLevelO2 && OptLevelO2.getPosition() < PassList.getPosition(i)) {
522 AddOptimizationPasses(Passes, *FPasses, 2, 0);
523 OptLevelO2 = false;
524 }
525
526 if (OptLevelOs && OptLevelOs.getPosition() < PassList.getPosition(i)) {
527 AddOptimizationPasses(Passes, *FPasses, 2, 1);
528 OptLevelOs = false;
529 }
530
531 if (OptLevelOz && OptLevelOz.getPosition() < PassList.getPosition(i)) {
532 AddOptimizationPasses(Passes, *FPasses, 2, 2);
533 OptLevelOz = false;
534 }
535
536 if (OptLevelO3 && OptLevelO3.getPosition() < PassList.getPosition(i)) {
537 AddOptimizationPasses(Passes, *FPasses, 3, 0);
538 OptLevelO3 = false;
539 }
540
541 const PassInfo *PassInf = PassList[i];
542 Pass *P = nullptr;
543 if (PassInf->getTargetMachineCtor())
544 P = PassInf->getTargetMachineCtor()(TM.get());
545 else if (PassInf->getNormalCtor())
546 P = PassInf->getNormalCtor()();
547 else
548 errs() << argv[0] << ": cannot create pass: "
549 << PassInf->getPassName() << "\n";
550 if (P) {
551 PassKind Kind = P->getPassKind();
552 addPass(Passes, P);
553
554 if (AnalyzeOnly) {
555 switch (Kind) {
556 case PT_BasicBlock:
557 Passes.add(createBasicBlockPassPrinter(PassInf, Out->os(), Quiet));
558 break;
559 case PT_Region:
560 Passes.add(createRegionPassPrinter(PassInf, Out->os(), Quiet));
561 break;
562 case PT_Loop:
563 Passes.add(createLoopPassPrinter(PassInf, Out->os(), Quiet));
564 break;
565 case PT_Function:
566 Passes.add(createFunctionPassPrinter(PassInf, Out->os(), Quiet));
567 break;
568 case PT_CallGraphSCC:
569 Passes.add(createCallGraphPassPrinter(PassInf, Out->os(), Quiet));
570 break;
571 default:
572 Passes.add(createModulePassPrinter(PassInf, Out->os(), Quiet));
573 break;
574 }
575 }
576 }
577
578 if (PrintEachXForm)
579 Passes.add(createPrintModulePass(errs()));
580 }
581
582 // If -std-compile-opts was specified at the end of the pass list, add them.
583 if (StandardCompileOpts) {
584 AddStandardCompilePasses(Passes);
585 StandardCompileOpts = false;
586 }
587
588 if (StandardLinkOpts) {
589 AddStandardLinkPasses(Passes);
590 StandardLinkOpts = false;
591 }
592
593 if (OptLevelO1)
594 AddOptimizationPasses(Passes, *FPasses, 1, 0);
595
596 if (OptLevelO2)
597 AddOptimizationPasses(Passes, *FPasses, 2, 0);
598
599 if (OptLevelOs)
600 AddOptimizationPasses(Passes, *FPasses, 2, 1);
601
602 if (OptLevelOz)
603 AddOptimizationPasses(Passes, *FPasses, 2, 2);
604
605 if (OptLevelO3)
606 AddOptimizationPasses(Passes, *FPasses, 3, 0);
607
608 if (OptLevelO1 || OptLevelO2 || OptLevelOs || OptLevelOz || OptLevelO3) {
609 FPasses->doInitialization();
610 for (Module::iterator F = M->begin(), E = M->end(); F != E; ++F)
611 FPasses->run(*F);
612 FPasses->doFinalization();
613 }
614
615 // Check that the module is well formed on completion of optimization
616 if (!NoVerify && !VerifyEach) {
617 Passes.add(createVerifierPass());
618 Passes.add(createDebugInfoVerifierPass());
619 }
620
621 // Write bitcode or assembly to the output as the last step...
622 if (!NoOutput && !AnalyzeOnly) {
623 if (OutputAssembly)
624 Passes.add(createPrintModulePass(Out->os()));
625 else
626 Passes.add(createBitcodeWriterPass(Out->os()));
627 }
628
629 // Before executing passes, print the final values of the LLVM options.
630 cl::PrintOptionValues();
631
632 // Now that we have all of the passes ready, run them.
633 Passes.run(*M.get());
634
635 // Declare success.
636 if (!NoOutput || PrintBreakpoints)
637 Out->keep();
638
639 return 0;
640 }
641