1 //===- opt.cpp - The LLVM Modular Optimizer -------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Optimizations may be specified an arbitrary number of times on the command
11 // line, They are run in the order specified.
13 //===----------------------------------------------------------------------===//
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/Analysis/TargetLibraryInfo.h"
24 #include "llvm/Analysis/TargetTransformInfo.h"
25 #include "llvm/Bitcode/BitcodeWriterPass.h"
26 #include "llvm/CodeGen/CommandFlags.def"
27 #include "llvm/CodeGen/TargetPassConfig.h"
28 #include "llvm/IR/DataLayout.h"
29 #include "llvm/IR/DebugInfo.h"
30 #include "llvm/IR/IRPrintingPasses.h"
31 #include "llvm/IR/LLVMContext.h"
32 #include "llvm/IR/LegacyPassManager.h"
33 #include "llvm/IR/LegacyPassNameParser.h"
34 #include "llvm/IR/Module.h"
35 #include "llvm/IR/Verifier.h"
36 #include "llvm/IRReader/IRReader.h"
37 #include "llvm/InitializePasses.h"
38 #include "llvm/LinkAllIR.h"
39 #include "llvm/LinkAllPasses.h"
40 #include "llvm/MC/SubtargetFeature.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/FileSystem.h"
43 #include "llvm/Support/Host.h"
44 #include "llvm/Support/ManagedStatic.h"
45 #include "llvm/Support/PluginLoader.h"
46 #include "llvm/Support/PrettyStackTrace.h"
47 #include "llvm/Support/Signals.h"
48 #include "llvm/Support/SourceMgr.h"
49 #include "llvm/Support/SystemUtils.h"
50 #include "llvm/Support/TargetRegistry.h"
51 #include "llvm/Support/TargetSelect.h"
52 #include "llvm/Support/ToolOutputFile.h"
53 #include "llvm/Support/YAMLTraits.h"
54 #include "llvm/Target/TargetMachine.h"
55 #include "llvm/Transforms/Coroutines.h"
56 #include "llvm/Transforms/IPO/AlwaysInliner.h"
57 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
58 #include "llvm/Transforms/Utils/Cloning.h"
62 using namespace opt_tool;
64 // The OptimizationList is automatically populated with registered Passes by the
67 static cl::list<const PassInfo*, bool, PassNameParser>
68 PassList(cl::desc("Optimizations available:"));
70 // This flag specifies a textual description of the optimization pass pipeline
71 // to run over the module. This flag switches opt to use the new pass manager
72 // infrastructure, completely disabling all of the flags specific to the old
74 static cl::opt<std::string> PassPipeline(
76 cl::desc("A textual description of the pass pipeline for optimizing"),
79 // Other command line options...
81 static cl::opt<std::string>
82 InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
83 cl::init("-"), cl::value_desc("filename"));
85 static cl::opt<std::string>
86 OutputFilename("o", cl::desc("Override output filename"),
87 cl::value_desc("filename"));
90 Force("f", cl::desc("Enable binary output on terminals"));
93 PrintEachXForm("p", cl::desc("Print module after each transformation"));
96 NoOutput("disable-output",
97 cl::desc("Do not write result bitcode file"), cl::Hidden);
100 OutputAssembly("S", cl::desc("Write output as LLVM assembly"));
103 OutputThinLTOBC("thinlto-bc",
104 cl::desc("Write output as ThinLTO-ready bitcode"));
106 static cl::opt<std::string> ThinLinkBitcodeFile(
107 "thin-link-bitcode-file", cl::value_desc("filename"),
109 "A file in which to write minimized bitcode for the thin link only"));
112 NoVerify("disable-verify", cl::desc("Do not run the verifier"), cl::Hidden);
115 VerifyEach("verify-each", cl::desc("Verify after each transform"));
118 DisableDITypeMap("disable-debug-info-type-map",
119 cl::desc("Don't use a uniquing type map for debug info"));
122 StripDebug("strip-debug",
123 cl::desc("Strip debugger symbol info from translation unit"));
126 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
129 DisableOptimizations("disable-opt",
130 cl::desc("Do not run any optimization passes"));
133 StandardLinkOpts("std-link-opts",
134 cl::desc("Include the standard link time optimizations"));
138 cl::desc("Optimization level 0. Similar to clang -O0"));
142 cl::desc("Optimization level 1. Similar to clang -O1"));
146 cl::desc("Optimization level 2. Similar to clang -O2"));
150 cl::desc("Like -O2 with extra optimizations for size. Similar to clang -Os"));
154 cl::desc("Like -Os but reduces code size further. Similar to clang -Oz"));
158 cl::desc("Optimization level 3. Similar to clang -O3"));
160 static cl::opt<unsigned>
161 CodeGenOptLevel("codegen-opt-level",
162 cl::desc("Override optimization level for codegen hooks"));
164 static cl::opt<std::string>
165 TargetTriple("mtriple", cl::desc("Override target triple for module"));
168 UnitAtATime("funit-at-a-time",
169 cl::desc("Enable IPO. This corresponds to gcc's -funit-at-a-time"),
173 DisableLoopUnrolling("disable-loop-unrolling",
174 cl::desc("Disable loop unrolling in all relevant passes"),
177 DisableLoopVectorization("disable-loop-vectorization",
178 cl::desc("Disable the loop vectorization pass"),
182 DisableSLPVectorization("disable-slp-vectorization",
183 cl::desc("Disable the slp vectorization pass"),
186 static cl::opt<bool> EmitSummaryIndex("module-summary",
187 cl::desc("Emit module summary index"),
190 static cl::opt<bool> EmitModuleHash("module-hash", cl::desc("Emit module hash"),
194 DisableSimplifyLibCalls("disable-simplify-libcalls",
195 cl::desc("Disable simplify-libcalls"));
198 Quiet("q", cl::desc("Obsolete option"), cl::Hidden);
201 QuietA("quiet", cl::desc("Alias for -q"), cl::aliasopt(Quiet));
204 AnalyzeOnly("analyze", cl::desc("Only perform analysis, no optimization"));
207 PrintBreakpoints("print-breakpoints-for-testing",
208 cl::desc("Print select breakpoints location for testing"));
210 static cl::opt<std::string> ClDataLayout("data-layout",
211 cl::desc("data layout string to use"),
212 cl::value_desc("layout-string"),
215 static cl::opt<bool> PreserveBitcodeUseListOrder(
216 "preserve-bc-uselistorder",
217 cl::desc("Preserve use-list order when writing LLVM bitcode."),
218 cl::init(true), cl::Hidden);
220 static cl::opt<bool> PreserveAssemblyUseListOrder(
221 "preserve-ll-uselistorder",
222 cl::desc("Preserve use-list order when writing LLVM assembly."),
223 cl::init(false), cl::Hidden);
226 RunTwice("run-twice",
227 cl::desc("Run all passes twice, re-using the same pass manager."),
228 cl::init(false), cl::Hidden);
230 static cl::opt<bool> DiscardValueNames(
231 "discard-value-names",
232 cl::desc("Discard names from Value (other than GlobalValue)."),
233 cl::init(false), cl::Hidden);
235 static cl::opt<bool> Coroutines(
237 cl::desc("Enable coroutine passes."),
238 cl::init(false), cl::Hidden);
240 static cl::opt<bool> PassRemarksWithHotness(
241 "pass-remarks-with-hotness",
242 cl::desc("With PGO, include profile count in optimization remarks"),
245 static cl::opt<unsigned> PassRemarksHotnessThreshold(
246 "pass-remarks-hotness-threshold",
247 cl::desc("Minimum profile count required for an optimization remark to be output"),
250 static cl::opt<std::string>
251 RemarksFilename("pass-remarks-output",
252 cl::desc("YAML output filename for pass remarks"),
253 cl::value_desc("filename"));
255 static inline void addPass(legacy::PassManagerBase &PM, Pass *P) {
256 // Add the pass to the pass manager...
259 // If we are verifying all of the intermediate steps, add the verifier...
261 PM.add(createVerifierPass());
264 /// This routine adds optimization passes based on selected optimization level,
267 /// OptLevel - Optimization Level
268 static void AddOptimizationPasses(legacy::PassManagerBase &MPM,
269 legacy::FunctionPassManager &FPM,
270 TargetMachine *TM, unsigned OptLevel,
271 unsigned SizeLevel) {
272 if (!NoVerify || VerifyEach)
273 FPM.add(createVerifierPass()); // Verify that input is correct
275 PassManagerBuilder Builder;
276 Builder.OptLevel = OptLevel;
277 Builder.SizeLevel = SizeLevel;
281 } else if (OptLevel > 1) {
282 Builder.Inliner = createFunctionInliningPass(OptLevel, SizeLevel, false);
284 Builder.Inliner = createAlwaysInlinerLegacyPass();
286 Builder.DisableUnitAtATime = !UnitAtATime;
287 Builder.DisableUnrollLoops = (DisableLoopUnrolling.getNumOccurrences() > 0) ?
288 DisableLoopUnrolling : OptLevel == 0;
290 // This is final, unless there is a #pragma vectorize enable
291 if (DisableLoopVectorization)
292 Builder.LoopVectorize = false;
293 // If option wasn't forced via cmd line (-vectorize-loops, -loop-vectorize)
294 else if (!Builder.LoopVectorize)
295 Builder.LoopVectorize = OptLevel > 1 && SizeLevel < 2;
297 // When #pragma vectorize is on for SLP, do the same as above
298 Builder.SLPVectorize =
299 DisableSLPVectorization ? false : OptLevel > 1 && SizeLevel < 2;
302 TM->adjustPassManager(Builder);
305 addCoroutinePassesToExtensionPoints(Builder);
307 Builder.populateFunctionPassManager(FPM);
308 Builder.populateModulePassManager(MPM);
311 static void AddStandardLinkPasses(legacy::PassManagerBase &PM) {
312 PassManagerBuilder Builder;
313 Builder.VerifyInput = true;
314 if (DisableOptimizations)
315 Builder.OptLevel = 0;
318 Builder.Inliner = createFunctionInliningPass();
319 Builder.populateLTOPassManager(PM);
322 //===----------------------------------------------------------------------===//
323 // CodeGen-related helper functions.
326 static CodeGenOpt::Level GetCodeGenOptLevel() {
327 if (CodeGenOptLevel.getNumOccurrences())
328 return static_cast<CodeGenOpt::Level>(unsigned(CodeGenOptLevel));
330 return CodeGenOpt::Less;
332 return CodeGenOpt::Default;
334 return CodeGenOpt::Aggressive;
335 return CodeGenOpt::None;
338 // Returns the TargetMachine instance or zero if no triple is provided.
339 static TargetMachine* GetTargetMachine(Triple TheTriple, StringRef CPUStr,
340 StringRef FeaturesStr,
341 const TargetOptions &Options) {
343 const Target *TheTarget = TargetRegistry::lookupTarget(MArch, TheTriple,
345 // Some modules don't specify a triple, and this is okay.
350 return TheTarget->createTargetMachine(TheTriple.getTriple(), CPUStr,
351 FeaturesStr, Options, getRelocModel(),
352 getCodeModel(), GetCodeGenOptLevel());
355 #ifdef LINK_POLLY_INTO_TOOLS
357 void initializePollyPasses(llvm::PassRegistry &Registry);
361 //===----------------------------------------------------------------------===//
364 int main(int argc, char **argv) {
365 sys::PrintStackTraceOnErrorSignal(argv[0]);
366 llvm::PrettyStackTraceProgram X(argc, argv);
368 // Enable debug stream buffering.
369 EnableDebugBuffering = true;
371 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
374 InitializeAllTargets();
375 InitializeAllTargetMCs();
376 InitializeAllAsmPrinters();
377 InitializeAllAsmParsers();
380 PassRegistry &Registry = *PassRegistry::getPassRegistry();
381 initializeCore(Registry);
382 initializeCoroutines(Registry);
383 initializeScalarOpts(Registry);
384 initializeObjCARCOpts(Registry);
385 initializeVectorization(Registry);
386 initializeIPO(Registry);
387 initializeAnalysis(Registry);
388 initializeTransformUtils(Registry);
389 initializeInstCombine(Registry);
390 initializeInstrumentation(Registry);
391 initializeTarget(Registry);
392 // For codegen passes, only passes that do IR to IR transformation are
394 initializeExpandMemCmpPassPass(Registry);
395 initializeScalarizeMaskedMemIntrinPass(Registry);
396 initializeCodeGenPreparePass(Registry);
397 initializeAtomicExpandPass(Registry);
398 initializeRewriteSymbolsLegacyPassPass(Registry);
399 initializeWinEHPreparePass(Registry);
400 initializeDwarfEHPreparePass(Registry);
401 initializeSafeStackLegacyPassPass(Registry);
402 initializeSjLjEHPreparePass(Registry);
403 initializePreISelIntrinsicLoweringLegacyPassPass(Registry);
404 initializeGlobalMergePass(Registry);
405 initializeInterleavedAccessPass(Registry);
406 initializeEntryExitInstrumenterPass(Registry);
407 initializePostInlineEntryExitInstrumenterPass(Registry);
408 initializeUnreachableBlockElimLegacyPassPass(Registry);
409 initializeExpandReductionsPass(Registry);
410 initializeWriteBitcodePassPass(Registry);
412 #ifdef LINK_POLLY_INTO_TOOLS
413 polly::initializePollyPasses(Registry);
416 cl::ParseCommandLineOptions(argc, argv,
417 "llvm .bc -> .bc modular optimizer and analysis printer\n");
419 if (AnalyzeOnly && NoOutput) {
420 errs() << argv[0] << ": analyze mode conflicts with no-output mode.\n";
426 Context.setDiscardValueNames(DiscardValueNames);
427 if (!DisableDITypeMap)
428 Context.enableDebugTypeODRUniquing();
430 if (PassRemarksWithHotness)
431 Context.setDiagnosticsHotnessRequested(true);
433 if (PassRemarksHotnessThreshold)
434 Context.setDiagnosticsHotnessThreshold(PassRemarksHotnessThreshold);
436 std::unique_ptr<ToolOutputFile> OptRemarkFile;
437 if (RemarksFilename != "") {
440 llvm::make_unique<ToolOutputFile>(RemarksFilename, EC, sys::fs::F_None);
442 errs() << EC.message() << '\n';
445 Context.setDiagnosticsOutputFile(
446 llvm::make_unique<yaml::Output>(OptRemarkFile->os()));
449 // Load the input module...
450 std::unique_ptr<Module> M =
451 parseIRFile(InputFilename, Err, Context, !NoVerify);
454 Err.print(argv[0], errs());
458 // Strip debug info before running the verifier.
462 // Immediately run the verifier to catch any problems before starting up the
463 // pass pipelines. Otherwise we can crash on broken code during
464 // doInitialization().
465 if (!NoVerify && verifyModule(*M, &errs())) {
466 errs() << argv[0] << ": " << InputFilename
467 << ": error: input module is broken!\n";
471 // If we are supposed to override the target triple or data layout, do so now.
472 if (!TargetTriple.empty())
473 M->setTargetTriple(Triple::normalize(TargetTriple));
474 if (!ClDataLayout.empty())
475 M->setDataLayout(ClDataLayout);
477 // Figure out what stream we are supposed to write to...
478 std::unique_ptr<ToolOutputFile> Out;
479 std::unique_ptr<ToolOutputFile> ThinLinkOut;
481 if (!OutputFilename.empty())
482 errs() << "WARNING: The -o (output filename) option is ignored when\n"
483 "the --disable-output option is used.\n";
485 // Default to standard output.
486 if (OutputFilename.empty())
487 OutputFilename = "-";
490 Out.reset(new ToolOutputFile(OutputFilename, EC, sys::fs::F_None));
492 errs() << EC.message() << '\n';
496 if (!ThinLinkBitcodeFile.empty()) {
498 new ToolOutputFile(ThinLinkBitcodeFile, EC, sys::fs::F_None));
500 errs() << EC.message() << '\n';
506 Triple ModuleTriple(M->getTargetTriple());
507 std::string CPUStr, FeaturesStr;
508 TargetMachine *Machine = nullptr;
509 const TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
511 if (ModuleTriple.getArch()) {
512 CPUStr = getCPUStr();
513 FeaturesStr = getFeaturesStr();
514 Machine = GetTargetMachine(ModuleTriple, CPUStr, FeaturesStr, Options);
517 std::unique_ptr<TargetMachine> TM(Machine);
519 // Override function attributes based on CPUStr, FeaturesStr, and command line
521 setFunctionAttributes(CPUStr, FeaturesStr, *M);
523 // If the output is set to be emitted to standard out, and standard out is a
524 // console, print out a warning message and refuse to do it. We don't
525 // impress anyone by spewing tons of binary goo to a terminal.
526 if (!Force && !NoOutput && !AnalyzeOnly && !OutputAssembly)
527 if (CheckBitcodeOutputToConsole(Out->os(), !Quiet))
530 if (PassPipeline.getNumOccurrences() > 0) {
531 OutputKind OK = OK_NoOutput;
535 : (OutputThinLTOBC ? OK_OutputThinLTOBitcode : OK_OutputBitcode);
537 VerifierKind VK = VK_VerifyInAndOut;
541 VK = VK_VerifyEachPass;
543 // The user has asked to use the new pass manager and provided a pipeline
544 // string. Hand off the rest of the functionality to the new code for that
546 return runPassPipeline(argv[0], *M, TM.get(), Out.get(), ThinLinkOut.get(),
547 OptRemarkFile.get(), PassPipeline, OK, VK,
548 PreserveAssemblyUseListOrder,
549 PreserveBitcodeUseListOrder, EmitSummaryIndex,
555 // Create a PassManager to hold and optimize the collection of passes we are
558 legacy::PassManager Passes;
560 // Add an appropriate TargetLibraryInfo pass for the module's triple.
561 TargetLibraryInfoImpl TLII(ModuleTriple);
563 // The -disable-simplify-libcalls flag actually disables all builtin optzns.
564 if (DisableSimplifyLibCalls)
565 TLII.disableAllFunctions();
566 Passes.add(new TargetLibraryInfoWrapperPass(TLII));
568 // Add internal analysis passes from the target machine.
569 Passes.add(createTargetTransformInfoWrapperPass(TM ? TM->getTargetIRAnalysis()
570 : TargetIRAnalysis()));
572 std::unique_ptr<legacy::FunctionPassManager> FPasses;
573 if (OptLevelO0 || OptLevelO1 || OptLevelO2 || OptLevelOs || OptLevelOz ||
575 FPasses.reset(new legacy::FunctionPassManager(M.get()));
576 FPasses->add(createTargetTransformInfoWrapperPass(
577 TM ? TM->getTargetIRAnalysis() : TargetIRAnalysis()));
580 if (PrintBreakpoints) {
581 // Default to standard output.
583 if (OutputFilename.empty())
584 OutputFilename = "-";
587 Out = llvm::make_unique<ToolOutputFile>(OutputFilename, EC,
590 errs() << EC.message() << '\n';
594 Passes.add(createBreakpointPrinter(Out->os()));
599 // FIXME: We should dyn_cast this when supported.
600 auto <M = static_cast<LLVMTargetMachine &>(*TM);
601 Pass *TPC = LTM.createPassConfig(Passes);
605 // Create a new optimization pass for each one specified on the command line
606 for (unsigned i = 0; i < PassList.size(); ++i) {
607 if (StandardLinkOpts &&
608 StandardLinkOpts.getPosition() < PassList.getPosition(i)) {
609 AddStandardLinkPasses(Passes);
610 StandardLinkOpts = false;
613 if (OptLevelO0 && OptLevelO0.getPosition() < PassList.getPosition(i)) {
614 AddOptimizationPasses(Passes, *FPasses, TM.get(), 0, 0);
618 if (OptLevelO1 && OptLevelO1.getPosition() < PassList.getPosition(i)) {
619 AddOptimizationPasses(Passes, *FPasses, TM.get(), 1, 0);
623 if (OptLevelO2 && OptLevelO2.getPosition() < PassList.getPosition(i)) {
624 AddOptimizationPasses(Passes, *FPasses, TM.get(), 2, 0);
628 if (OptLevelOs && OptLevelOs.getPosition() < PassList.getPosition(i)) {
629 AddOptimizationPasses(Passes, *FPasses, TM.get(), 2, 1);
633 if (OptLevelOz && OptLevelOz.getPosition() < PassList.getPosition(i)) {
634 AddOptimizationPasses(Passes, *FPasses, TM.get(), 2, 2);
638 if (OptLevelO3 && OptLevelO3.getPosition() < PassList.getPosition(i)) {
639 AddOptimizationPasses(Passes, *FPasses, TM.get(), 3, 0);
643 const PassInfo *PassInf = PassList[i];
645 if (PassInf->getNormalCtor())
646 P = PassInf->getNormalCtor()();
648 errs() << argv[0] << ": cannot create pass: "
649 << PassInf->getPassName() << "\n";
651 PassKind Kind = P->getPassKind();
657 Passes.add(createBasicBlockPassPrinter(PassInf, Out->os(), Quiet));
660 Passes.add(createRegionPassPrinter(PassInf, Out->os(), Quiet));
663 Passes.add(createLoopPassPrinter(PassInf, Out->os(), Quiet));
666 Passes.add(createFunctionPassPrinter(PassInf, Out->os(), Quiet));
668 case PT_CallGraphSCC:
669 Passes.add(createCallGraphPassPrinter(PassInf, Out->os(), Quiet));
672 Passes.add(createModulePassPrinter(PassInf, Out->os(), Quiet));
680 createPrintModulePass(errs(), "", PreserveAssemblyUseListOrder));
683 if (StandardLinkOpts) {
684 AddStandardLinkPasses(Passes);
685 StandardLinkOpts = false;
689 AddOptimizationPasses(Passes, *FPasses, TM.get(), 0, 0);
692 AddOptimizationPasses(Passes, *FPasses, TM.get(), 1, 0);
695 AddOptimizationPasses(Passes, *FPasses, TM.get(), 2, 0);
698 AddOptimizationPasses(Passes, *FPasses, TM.get(), 2, 1);
701 AddOptimizationPasses(Passes, *FPasses, TM.get(), 2, 2);
704 AddOptimizationPasses(Passes, *FPasses, TM.get(), 3, 0);
707 FPasses->doInitialization();
708 for (Function &F : *M)
710 FPasses->doFinalization();
713 // Check that the module is well formed on completion of optimization
714 if (!NoVerify && !VerifyEach)
715 Passes.add(createVerifierPass());
717 // In run twice mode, we want to make sure the output is bit-by-bit
718 // equivalent if we run the pass manager again, so setup two buffers and
719 // a stream to write to them. Note that llc does something similar and it
720 // may be worth to abstract this out in the future.
721 SmallVector<char, 0> Buffer;
722 SmallVector<char, 0> CompileTwiceBuffer;
723 std::unique_ptr<raw_svector_ostream> BOS;
724 raw_ostream *OS = nullptr;
726 // Write bitcode or assembly to the output as the last step...
727 if (!NoOutput && !AnalyzeOnly) {
731 BOS = make_unique<raw_svector_ostream>(Buffer);
734 if (OutputAssembly) {
735 if (EmitSummaryIndex)
736 report_fatal_error("Text output is incompatible with -module-summary");
738 report_fatal_error("Text output is incompatible with -module-hash");
739 Passes.add(createPrintModulePass(*OS, "", PreserveAssemblyUseListOrder));
740 } else if (OutputThinLTOBC)
741 Passes.add(createWriteThinLTOBitcodePass(
742 *OS, ThinLinkOut ? &ThinLinkOut->os() : nullptr));
744 Passes.add(createBitcodeWriterPass(*OS, PreserveBitcodeUseListOrder,
745 EmitSummaryIndex, EmitModuleHash));
748 // Before executing passes, print the final values of the LLVM options.
749 cl::PrintOptionValues();
751 // If requested, run all passes again with the same pass manager to catch
752 // bugs caused by persistent state in the passes
754 std::unique_ptr<Module> M2(CloneModule(M.get()));
756 CompileTwiceBuffer = Buffer;
760 // Now that we have all of the passes ready, run them.
763 // Compare the two outputs and make sure they're the same
766 if (Buffer.size() != CompileTwiceBuffer.size() ||
767 (memcmp(Buffer.data(), CompileTwiceBuffer.data(), Buffer.size()) !=
769 errs() << "Running the pass manager twice changed the output.\n"
770 "Writing the result of the second run to the specified output.\n"
771 "To generate the one-run comparison binary, just run without\n"
772 "the compile-twice option\n";
773 Out->os() << BOS->str();
776 OptRemarkFile->keep();
779 Out->os() << BOS->str();
783 if (!NoOutput || PrintBreakpoints)
787 OptRemarkFile->keep();