xref: /freebsd/contrib/llvm-project/llvm/tools/llc/llc.cpp (revision 162ae9c834f6d9f9cb443bd62cceb23e0b5fef48)
1 //===-- llc.cpp - Implement the LLVM Native Code Generator ----------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This is the llc code generator driver. It provides a convenient
10 // command-line interface for generating native assembly-language code
11 // or C code, given LLVM bitcode.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/ADT/STLExtras.h"
16 #include "llvm/ADT/Triple.h"
17 #include "llvm/Analysis/TargetLibraryInfo.h"
18 #include "llvm/CodeGen/CommandFlags.inc"
19 #include "llvm/CodeGen/LinkAllAsmWriterComponents.h"
20 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
21 #include "llvm/CodeGen/MIRParser/MIRParser.h"
22 #include "llvm/CodeGen/MachineFunctionPass.h"
23 #include "llvm/CodeGen/MachineModuleInfo.h"
24 #include "llvm/CodeGen/TargetPassConfig.h"
25 #include "llvm/CodeGen/TargetSubtargetInfo.h"
26 #include "llvm/IR/AutoUpgrade.h"
27 #include "llvm/IR/DataLayout.h"
28 #include "llvm/IR/DiagnosticInfo.h"
29 #include "llvm/IR/DiagnosticPrinter.h"
30 #include "llvm/IR/IRPrintingPasses.h"
31 #include "llvm/IR/LLVMContext.h"
32 #include "llvm/IR/LegacyPassManager.h"
33 #include "llvm/IR/Module.h"
34 #include "llvm/IR/RemarkStreamer.h"
35 #include "llvm/IR/Verifier.h"
36 #include "llvm/IRReader/IRReader.h"
37 #include "llvm/MC/SubtargetFeature.h"
38 #include "llvm/Pass.h"
39 #include "llvm/Support/CommandLine.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/FileSystem.h"
42 #include "llvm/Support/FormattedStream.h"
43 #include "llvm/Support/Host.h"
44 #include "llvm/Support/InitLLVM.h"
45 #include "llvm/Support/ManagedStatic.h"
46 #include "llvm/Support/PluginLoader.h"
47 #include "llvm/Support/SourceMgr.h"
48 #include "llvm/Support/TargetRegistry.h"
49 #include "llvm/Support/TargetSelect.h"
50 #include "llvm/Support/ToolOutputFile.h"
51 #include "llvm/Support/WithColor.h"
52 #include "llvm/Target/TargetMachine.h"
53 #include "llvm/Transforms/Utils/Cloning.h"
54 #include <memory>
55 using namespace llvm;
56 
57 // General options for llc.  Other pass-specific options are specified
58 // within the corresponding llc passes, and target-specific options
59 // and back-end code generation options are specified with the target machine.
60 //
61 static cl::opt<std::string>
62 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
63 
64 static cl::opt<std::string>
65 InputLanguage("x", cl::desc("Input language ('ir' or 'mir')"));
66 
67 static cl::opt<std::string>
68 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
69 
70 static cl::opt<std::string>
71     SplitDwarfOutputFile("split-dwarf-output",
72                          cl::desc(".dwo output filename"),
73                          cl::value_desc("filename"));
74 
75 static cl::opt<unsigned>
76 TimeCompilations("time-compilations", cl::Hidden, cl::init(1u),
77                  cl::value_desc("N"),
78                  cl::desc("Repeat compilation N times for timing"));
79 
80 static cl::opt<bool>
81 NoIntegratedAssembler("no-integrated-as", cl::Hidden,
82                       cl::desc("Disable integrated assembler"));
83 
84 static cl::opt<bool>
85     PreserveComments("preserve-as-comments", cl::Hidden,
86                      cl::desc("Preserve Comments in outputted assembly"),
87                      cl::init(true));
88 
89 // Determine optimization level.
90 static cl::opt<char>
91 OptLevel("O",
92          cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
93                   "(default = '-O2')"),
94          cl::Prefix,
95          cl::ZeroOrMore,
96          cl::init(' '));
97 
98 static cl::opt<std::string>
99 TargetTriple("mtriple", cl::desc("Override target triple for module"));
100 
101 static cl::opt<std::string> SplitDwarfFile(
102     "split-dwarf-file",
103     cl::desc(
104         "Specify the name of the .dwo file to encode in the DWARF output"));
105 
106 static cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
107                               cl::desc("Do not verify input module"));
108 
109 static cl::opt<bool> DisableSimplifyLibCalls("disable-simplify-libcalls",
110                                              cl::desc("Disable simplify-libcalls"));
111 
112 static cl::opt<bool> ShowMCEncoding("show-mc-encoding", cl::Hidden,
113                                     cl::desc("Show encoding in .s output"));
114 
115 static cl::opt<bool> EnableDwarfDirectory(
116     "enable-dwarf-directory", cl::Hidden,
117     cl::desc("Use .file directives with an explicit directory."));
118 
119 static cl::opt<bool> AsmVerbose("asm-verbose",
120                                 cl::desc("Add comments to directives."),
121                                 cl::init(true));
122 
123 static cl::opt<bool>
124     CompileTwice("compile-twice", cl::Hidden,
125                  cl::desc("Run everything twice, re-using the same pass "
126                           "manager and verify the result is the same."),
127                  cl::init(false));
128 
129 static cl::opt<bool> DiscardValueNames(
130     "discard-value-names",
131     cl::desc("Discard names from Value (other than GlobalValue)."),
132     cl::init(false), cl::Hidden);
133 
134 static cl::list<std::string> IncludeDirs("I", cl::desc("include search path"));
135 
136 static cl::opt<bool> RemarksWithHotness(
137     "pass-remarks-with-hotness",
138     cl::desc("With PGO, include profile count in optimization remarks"),
139     cl::Hidden);
140 
141 static cl::opt<unsigned>
142     RemarksHotnessThreshold("pass-remarks-hotness-threshold",
143                             cl::desc("Minimum profile count required for "
144                                      "an optimization remark to be output"),
145                             cl::Hidden);
146 
147 static cl::opt<std::string>
148     RemarksFilename("pass-remarks-output",
149                     cl::desc("Output filename for pass remarks"),
150                     cl::value_desc("filename"));
151 
152 static cl::opt<std::string>
153     RemarksPasses("pass-remarks-filter",
154                   cl::desc("Only record optimization remarks from passes whose "
155                            "names match the given regular expression"),
156                   cl::value_desc("regex"));
157 
158 static cl::opt<std::string> RemarksFormat(
159     "pass-remarks-format",
160     cl::desc("The format used for serializing remarks (default: YAML)"),
161     cl::value_desc("format"), cl::init("yaml"));
162 
163 namespace {
164 static ManagedStatic<std::vector<std::string>> RunPassNames;
165 
166 struct RunPassOption {
167   void operator=(const std::string &Val) const {
168     if (Val.empty())
169       return;
170     SmallVector<StringRef, 8> PassNames;
171     StringRef(Val).split(PassNames, ',', -1, false);
172     for (auto PassName : PassNames)
173       RunPassNames->push_back(PassName);
174   }
175 };
176 }
177 
178 static RunPassOption RunPassOpt;
179 
180 static cl::opt<RunPassOption, true, cl::parser<std::string>> RunPass(
181     "run-pass",
182     cl::desc("Run compiler only for specified passes (comma separated list)"),
183     cl::value_desc("pass-name"), cl::ZeroOrMore, cl::location(RunPassOpt));
184 
185 static int compileModule(char **, LLVMContext &);
186 
187 static std::unique_ptr<ToolOutputFile> GetOutputStream(const char *TargetName,
188                                                        Triple::OSType OS,
189                                                        const char *ProgName) {
190   // If we don't yet have an output filename, make one.
191   if (OutputFilename.empty()) {
192     if (InputFilename == "-")
193       OutputFilename = "-";
194     else {
195       // If InputFilename ends in .bc or .ll, remove it.
196       StringRef IFN = InputFilename;
197       if (IFN.endswith(".bc") || IFN.endswith(".ll"))
198         OutputFilename = IFN.drop_back(3);
199       else if (IFN.endswith(".mir"))
200         OutputFilename = IFN.drop_back(4);
201       else
202         OutputFilename = IFN;
203 
204       switch (FileType) {
205       case TargetMachine::CGFT_AssemblyFile:
206         if (TargetName[0] == 'c') {
207           if (TargetName[1] == 0)
208             OutputFilename += ".cbe.c";
209           else if (TargetName[1] == 'p' && TargetName[2] == 'p')
210             OutputFilename += ".cpp";
211           else
212             OutputFilename += ".s";
213         } else
214           OutputFilename += ".s";
215         break;
216       case TargetMachine::CGFT_ObjectFile:
217         if (OS == Triple::Win32)
218           OutputFilename += ".obj";
219         else
220           OutputFilename += ".o";
221         break;
222       case TargetMachine::CGFT_Null:
223         OutputFilename += ".null";
224         break;
225       }
226     }
227   }
228 
229   // Decide if we need "binary" output.
230   bool Binary = false;
231   switch (FileType) {
232   case TargetMachine::CGFT_AssemblyFile:
233     break;
234   case TargetMachine::CGFT_ObjectFile:
235   case TargetMachine::CGFT_Null:
236     Binary = true;
237     break;
238   }
239 
240   // Open the file.
241   std::error_code EC;
242   sys::fs::OpenFlags OpenFlags = sys::fs::F_None;
243   if (!Binary)
244     OpenFlags |= sys::fs::F_Text;
245   auto FDOut = llvm::make_unique<ToolOutputFile>(OutputFilename, EC, OpenFlags);
246   if (EC) {
247     WithColor::error() << EC.message() << '\n';
248     return nullptr;
249   }
250 
251   return FDOut;
252 }
253 
254 struct LLCDiagnosticHandler : public DiagnosticHandler {
255   bool *HasError;
256   LLCDiagnosticHandler(bool *HasErrorPtr) : HasError(HasErrorPtr) {}
257   bool handleDiagnostics(const DiagnosticInfo &DI) override {
258     if (DI.getSeverity() == DS_Error)
259       *HasError = true;
260 
261     if (auto *Remark = dyn_cast<DiagnosticInfoOptimizationBase>(&DI))
262       if (!Remark->isEnabled())
263         return true;
264 
265     DiagnosticPrinterRawOStream DP(errs());
266     errs() << LLVMContext::getDiagnosticMessagePrefix(DI.getSeverity()) << ": ";
267     DI.print(DP);
268     errs() << "\n";
269     return true;
270   }
271 };
272 
273 static void InlineAsmDiagHandler(const SMDiagnostic &SMD, void *Context,
274                                  unsigned LocCookie) {
275   bool *HasError = static_cast<bool *>(Context);
276   if (SMD.getKind() == SourceMgr::DK_Error)
277     *HasError = true;
278 
279   SMD.print(nullptr, errs());
280 
281   // For testing purposes, we print the LocCookie here.
282   if (LocCookie)
283     WithColor::note() << "!srcloc = " << LocCookie << "\n";
284 }
285 
286 // main - Entry point for the llc compiler.
287 //
288 int main(int argc, char **argv) {
289   InitLLVM X(argc, argv);
290 
291   // Enable debug stream buffering.
292   EnableDebugBuffering = true;
293 
294   LLVMContext Context;
295 
296   // Initialize targets first, so that --version shows registered targets.
297   InitializeAllTargets();
298   InitializeAllTargetMCs();
299   InitializeAllAsmPrinters();
300   InitializeAllAsmParsers();
301 
302   // Initialize codegen and IR passes used by llc so that the -print-after,
303   // -print-before, and -stop-after options work.
304   PassRegistry *Registry = PassRegistry::getPassRegistry();
305   initializeCore(*Registry);
306   initializeCodeGen(*Registry);
307   initializeLoopStrengthReducePass(*Registry);
308   initializeLowerIntrinsicsPass(*Registry);
309   initializeEntryExitInstrumenterPass(*Registry);
310   initializePostInlineEntryExitInstrumenterPass(*Registry);
311   initializeUnreachableBlockElimLegacyPassPass(*Registry);
312   initializeConstantHoistingLegacyPassPass(*Registry);
313   initializeScalarOpts(*Registry);
314   initializeVectorization(*Registry);
315   initializeScalarizeMaskedMemIntrinPass(*Registry);
316   initializeExpandReductionsPass(*Registry);
317   initializeHardwareLoopsPass(*Registry);
318 
319   // Initialize debugging passes.
320   initializeScavengerTestPass(*Registry);
321 
322   // Register the target printer for --version.
323   cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
324 
325   cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
326 
327   Context.setDiscardValueNames(DiscardValueNames);
328 
329   // Set a diagnostic handler that doesn't exit on the first error
330   bool HasError = false;
331   Context.setDiagnosticHandler(
332       llvm::make_unique<LLCDiagnosticHandler>(&HasError));
333   Context.setInlineAsmDiagnosticHandler(InlineAsmDiagHandler, &HasError);
334 
335   Expected<std::unique_ptr<ToolOutputFile>> RemarksFileOrErr =
336       setupOptimizationRemarks(Context, RemarksFilename, RemarksPasses,
337                                RemarksFormat, RemarksWithHotness,
338                                RemarksHotnessThreshold);
339   if (Error E = RemarksFileOrErr.takeError()) {
340     WithColor::error(errs(), argv[0]) << toString(std::move(E)) << '\n';
341     return 1;
342   }
343   std::unique_ptr<ToolOutputFile> RemarksFile = std::move(*RemarksFileOrErr);
344 
345   if (InputLanguage != "" && InputLanguage != "ir" &&
346       InputLanguage != "mir") {
347     WithColor::error(errs(), argv[0])
348         << "input language must be '', 'IR' or 'MIR'\n";
349     return 1;
350   }
351 
352   // Compile the module TimeCompilations times to give better compile time
353   // metrics.
354   for (unsigned I = TimeCompilations; I; --I)
355     if (int RetVal = compileModule(argv, Context))
356       return RetVal;
357 
358   if (RemarksFile)
359     RemarksFile->keep();
360   return 0;
361 }
362 
363 static bool addPass(PassManagerBase &PM, const char *argv0,
364                     StringRef PassName, TargetPassConfig &TPC) {
365   if (PassName == "none")
366     return false;
367 
368   const PassRegistry *PR = PassRegistry::getPassRegistry();
369   const PassInfo *PI = PR->getPassInfo(PassName);
370   if (!PI) {
371     WithColor::error(errs(), argv0)
372         << "run-pass " << PassName << " is not registered.\n";
373     return true;
374   }
375 
376   Pass *P;
377   if (PI->getNormalCtor())
378     P = PI->getNormalCtor()();
379   else {
380     WithColor::error(errs(), argv0)
381         << "cannot create pass: " << PI->getPassName() << "\n";
382     return true;
383   }
384   std::string Banner = std::string("After ") + std::string(P->getPassName());
385   PM.add(P);
386   TPC.printAndVerify(Banner);
387 
388   return false;
389 }
390 
391 static int compileModule(char **argv, LLVMContext &Context) {
392   // Load the module to be compiled...
393   SMDiagnostic Err;
394   std::unique_ptr<Module> M;
395   std::unique_ptr<MIRParser> MIR;
396   Triple TheTriple;
397 
398   bool SkipModule = MCPU == "help" ||
399                     (!MAttrs.empty() && MAttrs.front() == "help");
400 
401   // If user just wants to list available options, skip module loading
402   if (!SkipModule) {
403     if (InputLanguage == "mir" ||
404         (InputLanguage == "" && StringRef(InputFilename).endswith(".mir"))) {
405       MIR = createMIRParserFromFile(InputFilename, Err, Context);
406       if (MIR)
407         M = MIR->parseIRModule();
408     } else
409       M = parseIRFile(InputFilename, Err, Context, false);
410     if (!M) {
411       Err.print(argv[0], WithColor::error(errs(), argv[0]));
412       return 1;
413     }
414 
415     // If we are supposed to override the target triple, do so now.
416     if (!TargetTriple.empty())
417       M->setTargetTriple(Triple::normalize(TargetTriple));
418     TheTriple = Triple(M->getTargetTriple());
419   } else {
420     TheTriple = Triple(Triple::normalize(TargetTriple));
421   }
422 
423   if (TheTriple.getTriple().empty())
424     TheTriple.setTriple(sys::getDefaultTargetTriple());
425 
426   // Get the target specific parser.
427   std::string Error;
428   const Target *TheTarget = TargetRegistry::lookupTarget(MArch, TheTriple,
429                                                          Error);
430   if (!TheTarget) {
431     WithColor::error(errs(), argv[0]) << Error;
432     return 1;
433   }
434 
435   std::string CPUStr = getCPUStr(), FeaturesStr = getFeaturesStr();
436 
437   CodeGenOpt::Level OLvl = CodeGenOpt::Default;
438   switch (OptLevel) {
439   default:
440     WithColor::error(errs(), argv[0]) << "invalid optimization level.\n";
441     return 1;
442   case ' ': break;
443   case '0': OLvl = CodeGenOpt::None; break;
444   case '1': OLvl = CodeGenOpt::Less; break;
445   case '2': OLvl = CodeGenOpt::Default; break;
446   case '3': OLvl = CodeGenOpt::Aggressive; break;
447   }
448 
449   TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
450   Options.DisableIntegratedAS = NoIntegratedAssembler;
451   Options.MCOptions.ShowMCEncoding = ShowMCEncoding;
452   Options.MCOptions.MCUseDwarfDirectory = EnableDwarfDirectory;
453   Options.MCOptions.AsmVerbose = AsmVerbose;
454   Options.MCOptions.PreserveAsmComments = PreserveComments;
455   Options.MCOptions.IASSearchPaths = IncludeDirs;
456   Options.MCOptions.SplitDwarfFile = SplitDwarfFile;
457 
458   std::unique_ptr<TargetMachine> Target(TheTarget->createTargetMachine(
459       TheTriple.getTriple(), CPUStr, FeaturesStr, Options, getRelocModel(),
460       getCodeModel(), OLvl));
461 
462   assert(Target && "Could not allocate target machine!");
463 
464   // If we don't have a module then just exit now. We do this down
465   // here since the CPU/Feature help is underneath the target machine
466   // creation.
467   if (SkipModule)
468     return 0;
469 
470   assert(M && "Should have exited if we didn't have a module!");
471   if (FloatABIForCalls != FloatABI::Default)
472     Options.FloatABIType = FloatABIForCalls;
473 
474   // Figure out where we are going to send the output.
475   std::unique_ptr<ToolOutputFile> Out =
476       GetOutputStream(TheTarget->getName(), TheTriple.getOS(), argv[0]);
477   if (!Out) return 1;
478 
479   std::unique_ptr<ToolOutputFile> DwoOut;
480   if (!SplitDwarfOutputFile.empty()) {
481     std::error_code EC;
482     DwoOut = llvm::make_unique<ToolOutputFile>(SplitDwarfOutputFile, EC,
483                                                sys::fs::F_None);
484     if (EC) {
485       WithColor::error(errs(), argv[0]) << EC.message() << '\n';
486       return 1;
487     }
488   }
489 
490   // Build up all of the passes that we want to do to the module.
491   legacy::PassManager PM;
492 
493   // Add an appropriate TargetLibraryInfo pass for the module's triple.
494   TargetLibraryInfoImpl TLII(Triple(M->getTargetTriple()));
495 
496   // The -disable-simplify-libcalls flag actually disables all builtin optzns.
497   if (DisableSimplifyLibCalls)
498     TLII.disableAllFunctions();
499   PM.add(new TargetLibraryInfoWrapperPass(TLII));
500 
501   // Add the target data from the target machine, if it exists, or the module.
502   M->setDataLayout(Target->createDataLayout());
503 
504   // This needs to be done after setting datalayout since it calls verifier
505   // to check debug info whereas verifier relies on correct datalayout.
506   UpgradeDebugInfo(*M);
507 
508   // Verify module immediately to catch problems before doInitialization() is
509   // called on any passes.
510   if (!NoVerify && verifyModule(*M, &errs())) {
511     std::string Prefix =
512         (Twine(argv[0]) + Twine(": ") + Twine(InputFilename)).str();
513     WithColor::error(errs(), Prefix) << "input module is broken!\n";
514     return 1;
515   }
516 
517   // Override function attributes based on CPUStr, FeaturesStr, and command line
518   // flags.
519   setFunctionAttributes(CPUStr, FeaturesStr, *M);
520 
521   if (RelaxAll.getNumOccurrences() > 0 &&
522       FileType != TargetMachine::CGFT_ObjectFile)
523     WithColor::warning(errs(), argv[0])
524         << ": warning: ignoring -mc-relax-all because filetype != obj";
525 
526   {
527     raw_pwrite_stream *OS = &Out->os();
528 
529     // Manually do the buffering rather than using buffer_ostream,
530     // so we can memcmp the contents in CompileTwice mode
531     SmallVector<char, 0> Buffer;
532     std::unique_ptr<raw_svector_ostream> BOS;
533     if ((FileType != TargetMachine::CGFT_AssemblyFile &&
534          !Out->os().supportsSeeking()) ||
535         CompileTwice) {
536       BOS = make_unique<raw_svector_ostream>(Buffer);
537       OS = BOS.get();
538     }
539 
540     const char *argv0 = argv[0];
541     LLVMTargetMachine &LLVMTM = static_cast<LLVMTargetMachine&>(*Target);
542     MachineModuleInfo *MMI = new MachineModuleInfo(&LLVMTM);
543 
544     // Construct a custom pass pipeline that starts after instruction
545     // selection.
546     if (!RunPassNames->empty()) {
547       if (!MIR) {
548         WithColor::warning(errs(), argv[0])
549             << "run-pass is for .mir file only.\n";
550         return 1;
551       }
552       TargetPassConfig &TPC = *LLVMTM.createPassConfig(PM);
553       if (TPC.hasLimitedCodeGenPipeline()) {
554         WithColor::warning(errs(), argv[0])
555             << "run-pass cannot be used with "
556             << TPC.getLimitedCodeGenPipelineReason(" and ") << ".\n";
557         return 1;
558       }
559 
560       TPC.setDisableVerify(NoVerify);
561       PM.add(&TPC);
562       PM.add(MMI);
563       TPC.printAndVerify("");
564       for (const std::string &RunPassName : *RunPassNames) {
565         if (addPass(PM, argv0, RunPassName, TPC))
566           return 1;
567       }
568       TPC.setInitialized();
569       PM.add(createPrintMIRPass(*OS));
570       PM.add(createFreeMachineFunctionPass());
571     } else if (Target->addPassesToEmitFile(PM, *OS,
572                                            DwoOut ? &DwoOut->os() : nullptr,
573                                            FileType, NoVerify, MMI)) {
574       WithColor::warning(errs(), argv[0])
575           << "target does not support generation of this"
576           << " file type!\n";
577       return 1;
578     }
579 
580     if (MIR) {
581       assert(MMI && "Forgot to create MMI?");
582       if (MIR->parseMachineFunctions(*M, *MMI))
583         return 1;
584     }
585 
586     // Before executing passes, print the final values of the LLVM options.
587     cl::PrintOptionValues();
588 
589     // If requested, run the pass manager over the same module again,
590     // to catch any bugs due to persistent state in the passes. Note that
591     // opt has the same functionality, so it may be worth abstracting this out
592     // in the future.
593     SmallVector<char, 0> CompileTwiceBuffer;
594     if (CompileTwice) {
595       std::unique_ptr<Module> M2(llvm::CloneModule(*M));
596       PM.run(*M2);
597       CompileTwiceBuffer = Buffer;
598       Buffer.clear();
599     }
600 
601     PM.run(*M);
602 
603     auto HasError =
604         ((const LLCDiagnosticHandler *)(Context.getDiagHandlerPtr()))->HasError;
605     if (*HasError)
606       return 1;
607 
608     // Compare the two outputs and make sure they're the same
609     if (CompileTwice) {
610       if (Buffer.size() != CompileTwiceBuffer.size() ||
611           (memcmp(Buffer.data(), CompileTwiceBuffer.data(), Buffer.size()) !=
612            0)) {
613         errs()
614             << "Running the pass manager twice changed the output.\n"
615                "Writing the result of the second run to the specified output\n"
616                "To generate the one-run comparison binary, just run without\n"
617                "the compile-twice option\n";
618         Out->os() << Buffer;
619         Out->keep();
620         return 1;
621       }
622     }
623 
624     if (BOS) {
625       Out->os() << Buffer;
626     }
627   }
628 
629   // Declare success.
630   Out->keep();
631   if (DwoOut)
632     DwoOut->keep();
633 
634   return 0;
635 }
636