xref: /freebsd/contrib/llvm-project/llvm/tools/llvm-mca/llvm-mca.cpp (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 //===-- llvm-mca.cpp - Machine Code Analyzer -------------------*- C++ -* -===//
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 utility is a simple driver that allows static performance analysis on
10 // machine code similarly to how IACA (Intel Architecture Code Analyzer) works.
11 //
12 //   llvm-mca [options] <file-name>
13 //      -march <type>
14 //      -mcpu <cpu>
15 //      -o <file>
16 //
17 // The target defaults to the host target.
18 // The cpu defaults to the 'native' host cpu.
19 // The output defaults to standard output.
20 //
21 //===----------------------------------------------------------------------===//
22 
23 #include "CodeRegion.h"
24 #include "CodeRegionGenerator.h"
25 #include "PipelinePrinter.h"
26 #include "Views/BottleneckAnalysis.h"
27 #include "Views/DispatchStatistics.h"
28 #include "Views/InstructionInfoView.h"
29 #include "Views/RegisterFileStatistics.h"
30 #include "Views/ResourcePressureView.h"
31 #include "Views/RetireControlUnitStatistics.h"
32 #include "Views/SchedulerStatistics.h"
33 #include "Views/SummaryView.h"
34 #include "Views/TimelineView.h"
35 #include "llvm/MC/MCAsmBackend.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/MC/MCCodeEmitter.h"
38 #include "llvm/MC/MCContext.h"
39 #include "llvm/MC/MCObjectFileInfo.h"
40 #include "llvm/MC/MCRegisterInfo.h"
41 #include "llvm/MC/MCSubtargetInfo.h"
42 #include "llvm/MC/MCTargetOptionsCommandFlags.h"
43 #include "llvm/MC/TargetRegistry.h"
44 #include "llvm/MCA/CodeEmitter.h"
45 #include "llvm/MCA/Context.h"
46 #include "llvm/MCA/CustomBehaviour.h"
47 #include "llvm/MCA/InstrBuilder.h"
48 #include "llvm/MCA/Pipeline.h"
49 #include "llvm/MCA/Stages/EntryStage.h"
50 #include "llvm/MCA/Stages/InstructionTables.h"
51 #include "llvm/MCA/Support.h"
52 #include "llvm/Support/CommandLine.h"
53 #include "llvm/Support/ErrorHandling.h"
54 #include "llvm/Support/ErrorOr.h"
55 #include "llvm/Support/FileSystem.h"
56 #include "llvm/Support/InitLLVM.h"
57 #include "llvm/Support/MemoryBuffer.h"
58 #include "llvm/Support/SourceMgr.h"
59 #include "llvm/Support/TargetSelect.h"
60 #include "llvm/Support/ToolOutputFile.h"
61 #include "llvm/Support/WithColor.h"
62 #include "llvm/TargetParser/Host.h"
63 
64 using namespace llvm;
65 
66 static mc::RegisterMCTargetOptionsFlags MOF;
67 
68 static cl::OptionCategory ToolOptions("Tool Options");
69 static cl::OptionCategory ViewOptions("View Options");
70 
71 static cl::opt<std::string> InputFilename(cl::Positional,
72                                           cl::desc("<input file>"),
73                                           cl::cat(ToolOptions), cl::init("-"));
74 
75 static cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"),
76                                            cl::init("-"), cl::cat(ToolOptions),
77                                            cl::value_desc("filename"));
78 
79 static cl::opt<std::string>
80     ArchName("march",
81              cl::desc("Target architecture. "
82                       "See -version for available targets"),
83              cl::cat(ToolOptions));
84 
85 static cl::opt<std::string>
86     TripleName("mtriple",
87                cl::desc("Target triple. See -version for available targets"),
88                cl::cat(ToolOptions));
89 
90 static cl::opt<std::string>
91     MCPU("mcpu",
92          cl::desc("Target a specific cpu type (-mcpu=help for details)"),
93          cl::value_desc("cpu-name"), cl::cat(ToolOptions), cl::init("native"));
94 
95 static cl::list<std::string>
96     MATTRS("mattr", cl::CommaSeparated,
97            cl::desc("Target specific attributes (-mattr=help for details)"),
98            cl::value_desc("a1,+a2,-a3,..."), cl::cat(ToolOptions));
99 
100 static cl::opt<bool> PrintJson("json",
101                                cl::desc("Print the output in json format"),
102                                cl::cat(ToolOptions), cl::init(false));
103 
104 static cl::opt<int>
105     OutputAsmVariant("output-asm-variant",
106                      cl::desc("Syntax variant to use for output printing"),
107                      cl::cat(ToolOptions), cl::init(-1));
108 
109 static cl::opt<bool>
110     PrintImmHex("print-imm-hex", cl::cat(ToolOptions), cl::init(false),
111                 cl::desc("Prefer hex format when printing immediate values"));
112 
113 static cl::opt<unsigned> Iterations("iterations",
114                                     cl::desc("Number of iterations to run"),
115                                     cl::cat(ToolOptions), cl::init(0));
116 
117 static cl::opt<unsigned>
118     DispatchWidth("dispatch", cl::desc("Override the processor dispatch width"),
119                   cl::cat(ToolOptions), cl::init(0));
120 
121 static cl::opt<unsigned>
122     RegisterFileSize("register-file-size",
123                      cl::desc("Maximum number of physical registers which can "
124                               "be used for register mappings"),
125                      cl::cat(ToolOptions), cl::init(0));
126 
127 static cl::opt<unsigned>
128     MicroOpQueue("micro-op-queue-size", cl::Hidden,
129                  cl::desc("Number of entries in the micro-op queue"),
130                  cl::cat(ToolOptions), cl::init(0));
131 
132 static cl::opt<unsigned>
133     DecoderThroughput("decoder-throughput", cl::Hidden,
134                       cl::desc("Maximum throughput from the decoders "
135                                "(instructions per cycle)"),
136                       cl::cat(ToolOptions), cl::init(0));
137 
138 static cl::opt<unsigned>
139     CallLatency("call-latency", cl::Hidden,
140                 cl::desc("Number of cycles to assume for a call instruction"),
141                 cl::cat(ToolOptions), cl::init(100U));
142 
143 enum class SkipType { NONE, LACK_SCHED, PARSE_FAILURE, ANY_FAILURE };
144 
145 static cl::opt<enum SkipType> SkipUnsupportedInstructions(
146     "skip-unsupported-instructions",
147     cl::desc("Force analysis to continue in the presence of unsupported "
148              "instructions"),
149     cl::values(
150         clEnumValN(SkipType::NONE, "none",
151                    "Exit with an error when an instruction is unsupported for "
152                    "any reason (default)"),
153         clEnumValN(
154             SkipType::LACK_SCHED, "lack-sched",
155             "Skip instructions on input which lack scheduling information"),
156         clEnumValN(
157             SkipType::PARSE_FAILURE, "parse-failure",
158             "Skip lines on the input which fail to parse for any reason"),
159         clEnumValN(SkipType::ANY_FAILURE, "any",
160                    "Skip instructions or lines on input which are unsupported "
161                    "for any reason")),
162     cl::init(SkipType::NONE), cl::cat(ViewOptions));
163 
shouldSkip(enum SkipType skipType)164 bool shouldSkip(enum SkipType skipType) {
165   if (SkipUnsupportedInstructions == SkipType::NONE)
166     return false;
167   if (SkipUnsupportedInstructions == SkipType::ANY_FAILURE)
168     return true;
169   return skipType == SkipUnsupportedInstructions;
170 }
171 
172 static cl::opt<bool>
173     PrintRegisterFileStats("register-file-stats",
174                            cl::desc("Print register file statistics"),
175                            cl::cat(ViewOptions), cl::init(false));
176 
177 static cl::opt<bool> PrintDispatchStats("dispatch-stats",
178                                         cl::desc("Print dispatch statistics"),
179                                         cl::cat(ViewOptions), cl::init(false));
180 
181 static cl::opt<bool>
182     PrintSummaryView("summary-view", cl::Hidden,
183                      cl::desc("Print summary view (enabled by default)"),
184                      cl::cat(ViewOptions), cl::init(true));
185 
186 static cl::opt<bool> PrintSchedulerStats("scheduler-stats",
187                                          cl::desc("Print scheduler statistics"),
188                                          cl::cat(ViewOptions), cl::init(false));
189 
190 static cl::opt<bool>
191     PrintRetireStats("retire-stats",
192                      cl::desc("Print retire control unit statistics"),
193                      cl::cat(ViewOptions), cl::init(false));
194 
195 static cl::opt<bool> PrintResourcePressureView(
196     "resource-pressure",
197     cl::desc("Print the resource pressure view (enabled by default)"),
198     cl::cat(ViewOptions), cl::init(true));
199 
200 static cl::opt<bool> PrintTimelineView("timeline",
201                                        cl::desc("Print the timeline view"),
202                                        cl::cat(ViewOptions), cl::init(false));
203 
204 static cl::opt<unsigned> TimelineMaxIterations(
205     "timeline-max-iterations",
206     cl::desc("Maximum number of iterations to print in timeline view"),
207     cl::cat(ViewOptions), cl::init(0));
208 
209 static cl::opt<unsigned>
210     TimelineMaxCycles("timeline-max-cycles",
211                       cl::desc("Maximum number of cycles in the timeline view, "
212                                "or 0 for unlimited. Defaults to 80 cycles"),
213                       cl::cat(ViewOptions), cl::init(80));
214 
215 static cl::opt<bool>
216     AssumeNoAlias("noalias",
217                   cl::desc("If set, assume that loads and stores do not alias"),
218                   cl::cat(ToolOptions), cl::init(true));
219 
220 static cl::opt<unsigned> LoadQueueSize("lqueue",
221                                        cl::desc("Size of the load queue"),
222                                        cl::cat(ToolOptions), cl::init(0));
223 
224 static cl::opt<unsigned> StoreQueueSize("squeue",
225                                         cl::desc("Size of the store queue"),
226                                         cl::cat(ToolOptions), cl::init(0));
227 
228 static cl::opt<bool>
229     PrintInstructionTables("instruction-tables",
230                            cl::desc("Print instruction tables"),
231                            cl::cat(ToolOptions), cl::init(false));
232 
233 static cl::opt<bool> PrintInstructionInfoView(
234     "instruction-info",
235     cl::desc("Print the instruction info view (enabled by default)"),
236     cl::cat(ViewOptions), cl::init(true));
237 
238 static cl::opt<bool> EnableAllStats("all-stats",
239                                     cl::desc("Print all hardware statistics"),
240                                     cl::cat(ViewOptions), cl::init(false));
241 
242 static cl::opt<bool>
243     EnableAllViews("all-views",
244                    cl::desc("Print all views including hardware statistics"),
245                    cl::cat(ViewOptions), cl::init(false));
246 
247 static cl::opt<bool> EnableBottleneckAnalysis(
248     "bottleneck-analysis",
249     cl::desc("Enable bottleneck analysis (disabled by default)"),
250     cl::cat(ViewOptions), cl::init(false));
251 
252 static cl::opt<bool> ShowEncoding(
253     "show-encoding",
254     cl::desc("Print encoding information in the instruction info view"),
255     cl::cat(ViewOptions), cl::init(false));
256 
257 static cl::opt<bool> ShowBarriers(
258     "show-barriers",
259     cl::desc("Print memory barrier information in the instruction info view"),
260     cl::cat(ViewOptions), cl::init(false));
261 
262 static cl::opt<bool> DisableCustomBehaviour(
263     "disable-cb",
264     cl::desc(
265         "Disable custom behaviour (use the default class which does nothing)."),
266     cl::cat(ViewOptions), cl::init(false));
267 
268 static cl::opt<bool> DisableInstrumentManager(
269     "disable-im",
270     cl::desc("Disable instrumentation manager (use the default class which "
271              "ignores instruments.)."),
272     cl::cat(ViewOptions), cl::init(false));
273 
274 namespace {
275 
getTarget(const char * ProgName)276 const Target *getTarget(const char *ProgName) {
277   if (TripleName.empty())
278     TripleName = Triple::normalize(sys::getDefaultTargetTriple());
279   Triple TheTriple(TripleName);
280 
281   // Get the target specific parser.
282   std::string Error;
283   const Target *TheTarget =
284       TargetRegistry::lookupTarget(ArchName, TheTriple, Error);
285   if (!TheTarget) {
286     errs() << ProgName << ": " << Error;
287     return nullptr;
288   }
289 
290   // Update TripleName with the updated triple from the target lookup.
291   TripleName = TheTriple.str();
292 
293   // Return the found target.
294   return TheTarget;
295 }
296 
getOutputStream()297 ErrorOr<std::unique_ptr<ToolOutputFile>> getOutputStream() {
298   if (OutputFilename == "")
299     OutputFilename = "-";
300   std::error_code EC;
301   auto Out = std::make_unique<ToolOutputFile>(OutputFilename, EC,
302                                               sys::fs::OF_TextWithCRLF);
303   if (!EC)
304     return std::move(Out);
305   return EC;
306 }
307 } // end of anonymous namespace
308 
processOptionImpl(cl::opt<bool> & O,const cl::opt<bool> & Default)309 static void processOptionImpl(cl::opt<bool> &O, const cl::opt<bool> &Default) {
310   if (!O.getNumOccurrences() || O.getPosition() < Default.getPosition())
311     O = Default.getValue();
312 }
313 
processViewOptions(bool IsOutOfOrder)314 static void processViewOptions(bool IsOutOfOrder) {
315   if (!EnableAllViews.getNumOccurrences() &&
316       !EnableAllStats.getNumOccurrences())
317     return;
318 
319   if (EnableAllViews.getNumOccurrences()) {
320     processOptionImpl(PrintSummaryView, EnableAllViews);
321     if (IsOutOfOrder)
322       processOptionImpl(EnableBottleneckAnalysis, EnableAllViews);
323     processOptionImpl(PrintResourcePressureView, EnableAllViews);
324     processOptionImpl(PrintTimelineView, EnableAllViews);
325     processOptionImpl(PrintInstructionInfoView, EnableAllViews);
326   }
327 
328   const cl::opt<bool> &Default =
329       EnableAllViews.getPosition() < EnableAllStats.getPosition()
330           ? EnableAllStats
331           : EnableAllViews;
332   processOptionImpl(PrintRegisterFileStats, Default);
333   processOptionImpl(PrintDispatchStats, Default);
334   processOptionImpl(PrintSchedulerStats, Default);
335   if (IsOutOfOrder)
336     processOptionImpl(PrintRetireStats, Default);
337 }
338 
339 // Returns true on success.
runPipeline(mca::Pipeline & P)340 static bool runPipeline(mca::Pipeline &P) {
341   // Handle pipeline errors here.
342   Expected<unsigned> Cycles = P.run();
343   if (!Cycles) {
344     WithColor::error() << toString(Cycles.takeError());
345     return false;
346   }
347   return true;
348 }
349 
main(int argc,char ** argv)350 int main(int argc, char **argv) {
351   InitLLVM X(argc, argv);
352 
353   // Initialize targets and assembly parsers.
354   InitializeAllTargetInfos();
355   InitializeAllTargetMCs();
356   InitializeAllAsmParsers();
357   InitializeAllTargetMCAs();
358 
359   // Register the Target and CPU printer for --version.
360   cl::AddExtraVersionPrinter(sys::printDefaultTargetAndDetectedCPU);
361 
362   // Enable printing of available targets when flag --version is specified.
363   cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
364 
365   cl::HideUnrelatedOptions({&ToolOptions, &ViewOptions});
366 
367   // Parse flags and initialize target options.
368   cl::ParseCommandLineOptions(argc, argv,
369                               "llvm machine code performance analyzer.\n");
370 
371   // Get the target from the triple. If a triple is not specified, then select
372   // the default triple for the host. If the triple doesn't correspond to any
373   // registered target, then exit with an error message.
374   const char *ProgName = argv[0];
375   const Target *TheTarget = getTarget(ProgName);
376   if (!TheTarget)
377     return 1;
378 
379   // GetTarget() may replaced TripleName with a default triple.
380   // For safety, reconstruct the Triple object.
381   Triple TheTriple(TripleName);
382 
383   ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr =
384       MemoryBuffer::getFileOrSTDIN(InputFilename);
385   if (std::error_code EC = BufferPtr.getError()) {
386     WithColor::error() << InputFilename << ": " << EC.message() << '\n';
387     return 1;
388   }
389 
390   if (MCPU == "native")
391     MCPU = std::string(llvm::sys::getHostCPUName());
392 
393   // Package up features to be passed to target/subtarget
394   std::string FeaturesStr;
395   if (MATTRS.size()) {
396     SubtargetFeatures Features;
397     for (std::string &MAttr : MATTRS)
398       Features.AddFeature(MAttr);
399     FeaturesStr = Features.getString();
400   }
401 
402   std::unique_ptr<MCSubtargetInfo> STI(
403       TheTarget->createMCSubtargetInfo(TripleName, MCPU, FeaturesStr));
404   assert(STI && "Unable to create subtarget info!");
405   if (!STI->isCPUStringValid(MCPU))
406     return 1;
407 
408   if (!STI->getSchedModel().hasInstrSchedModel()) {
409     WithColor::error()
410         << "unable to find instruction-level scheduling information for"
411         << " target triple '" << TheTriple.normalize() << "' and cpu '" << MCPU
412         << "'.\n";
413 
414     if (STI->getSchedModel().InstrItineraries)
415       WithColor::note()
416           << "cpu '" << MCPU << "' provides itineraries. However, "
417           << "instruction itineraries are currently unsupported.\n";
418     return 1;
419   }
420 
421   // Apply overrides to llvm-mca specific options.
422   bool IsOutOfOrder = STI->getSchedModel().isOutOfOrder();
423   processViewOptions(IsOutOfOrder);
424 
425   std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
426   assert(MRI && "Unable to create target register info!");
427 
428   MCTargetOptions MCOptions = mc::InitMCTargetOptionsFromFlags();
429   std::unique_ptr<MCAsmInfo> MAI(
430       TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
431   assert(MAI && "Unable to create target asm info!");
432 
433   SourceMgr SrcMgr;
434 
435   // Tell SrcMgr about this buffer, which is what the parser will pick up.
436   SrcMgr.AddNewSourceBuffer(std::move(*BufferPtr), SMLoc());
437 
438   std::unique_ptr<buffer_ostream> BOS;
439 
440   std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
441   assert(MCII && "Unable to create instruction info!");
442 
443   std::unique_ptr<MCInstrAnalysis> MCIA(
444       TheTarget->createMCInstrAnalysis(MCII.get()));
445 
446   // Need to initialize an MCInstPrinter as it is
447   // required for initializing the MCTargetStreamer
448   // which needs to happen within the CRG.parseAnalysisRegions() call below.
449   // Without an MCTargetStreamer, certain assembly directives can trigger a
450   // segfault. (For example, the .cv_fpo_proc directive on x86 will segfault if
451   // we don't initialize the MCTargetStreamer.)
452   unsigned IPtempOutputAsmVariant =
453       OutputAsmVariant == -1 ? 0 : OutputAsmVariant;
454   std::unique_ptr<MCInstPrinter> IPtemp(TheTarget->createMCInstPrinter(
455       Triple(TripleName), IPtempOutputAsmVariant, *MAI, *MCII, *MRI));
456   if (!IPtemp) {
457     WithColor::error()
458         << "unable to create instruction printer for target triple '"
459         << TheTriple.normalize() << "' with assembly variant "
460         << IPtempOutputAsmVariant << ".\n";
461     return 1;
462   }
463 
464   // Parse the input and create CodeRegions that llvm-mca can analyze.
465   MCContext ACtx(TheTriple, MAI.get(), MRI.get(), STI.get(), &SrcMgr);
466   std::unique_ptr<MCObjectFileInfo> AMOFI(
467       TheTarget->createMCObjectFileInfo(ACtx, /*PIC=*/false));
468   ACtx.setObjectFileInfo(AMOFI.get());
469   mca::AsmAnalysisRegionGenerator CRG(*TheTarget, SrcMgr, ACtx, *MAI, *STI,
470                                       *MCII);
471   Expected<const mca::AnalysisRegions &> RegionsOrErr =
472       CRG.parseAnalysisRegions(std::move(IPtemp),
473                                shouldSkip(SkipType::PARSE_FAILURE));
474   if (!RegionsOrErr) {
475     if (auto Err =
476             handleErrors(RegionsOrErr.takeError(), [](const StringError &E) {
477               WithColor::error() << E.getMessage() << '\n';
478             })) {
479       // Default case.
480       WithColor::error() << toString(std::move(Err)) << '\n';
481     }
482     return 1;
483   }
484   const mca::AnalysisRegions &Regions = *RegionsOrErr;
485 
486   // Early exit if errors were found by the code region parsing logic.
487   if (!Regions.isValid())
488     return 1;
489 
490   if (Regions.empty()) {
491     WithColor::error() << "no assembly instructions found.\n";
492     return 1;
493   }
494 
495   std::unique_ptr<mca::InstrumentManager> IM;
496   if (!DisableInstrumentManager) {
497     IM = std::unique_ptr<mca::InstrumentManager>(
498         TheTarget->createInstrumentManager(*STI, *MCII));
499   }
500   if (!IM) {
501     // If the target doesn't have its own IM implemented (or the -disable-cb
502     // flag is set) then we use the base class (which does nothing).
503     IM = std::make_unique<mca::InstrumentManager>(*STI, *MCII);
504   }
505 
506   // Parse the input and create InstrumentRegion that llvm-mca
507   // can use to improve analysis.
508   MCContext ICtx(TheTriple, MAI.get(), MRI.get(), STI.get(), &SrcMgr);
509   std::unique_ptr<MCObjectFileInfo> IMOFI(
510       TheTarget->createMCObjectFileInfo(ICtx, /*PIC=*/false));
511   ICtx.setObjectFileInfo(IMOFI.get());
512   mca::AsmInstrumentRegionGenerator IRG(*TheTarget, SrcMgr, ICtx, *MAI, *STI,
513                                         *MCII, *IM);
514   Expected<const mca::InstrumentRegions &> InstrumentRegionsOrErr =
515       IRG.parseInstrumentRegions(std::move(IPtemp),
516                                  shouldSkip(SkipType::PARSE_FAILURE));
517   if (!InstrumentRegionsOrErr) {
518     if (auto Err = handleErrors(InstrumentRegionsOrErr.takeError(),
519                                 [](const StringError &E) {
520                                   WithColor::error() << E.getMessage() << '\n';
521                                 })) {
522       // Default case.
523       WithColor::error() << toString(std::move(Err)) << '\n';
524     }
525     return 1;
526   }
527   const mca::InstrumentRegions &InstrumentRegions = *InstrumentRegionsOrErr;
528 
529   // Early exit if errors were found by the instrumentation parsing logic.
530   if (!InstrumentRegions.isValid())
531     return 1;
532 
533   // Now initialize the output file.
534   auto OF = getOutputStream();
535   if (std::error_code EC = OF.getError()) {
536     WithColor::error() << EC.message() << '\n';
537     return 1;
538   }
539 
540   unsigned AssemblerDialect = CRG.getAssemblerDialect();
541   if (OutputAsmVariant >= 0)
542     AssemblerDialect = static_cast<unsigned>(OutputAsmVariant);
543   std::unique_ptr<MCInstPrinter> IP(TheTarget->createMCInstPrinter(
544       Triple(TripleName), AssemblerDialect, *MAI, *MCII, *MRI));
545   if (!IP) {
546     WithColor::error()
547         << "unable to create instruction printer for target triple '"
548         << TheTriple.normalize() << "' with assembly variant "
549         << AssemblerDialect << ".\n";
550     return 1;
551   }
552 
553   // Set the display preference for hex vs. decimal immediates.
554   IP->setPrintImmHex(PrintImmHex);
555 
556   std::unique_ptr<ToolOutputFile> TOF = std::move(*OF);
557 
558   const MCSchedModel &SM = STI->getSchedModel();
559 
560   std::unique_ptr<mca::InstrPostProcess> IPP;
561   if (!DisableCustomBehaviour) {
562     // TODO: It may be a good idea to separate CB and IPP so that they can
563     // be used independently of each other. What I mean by this is to add
564     // an extra command-line arg --disable-ipp so that CB and IPP can be
565     // toggled without needing to toggle both of them together.
566     IPP = std::unique_ptr<mca::InstrPostProcess>(
567         TheTarget->createInstrPostProcess(*STI, *MCII));
568   }
569   if (!IPP) {
570     // If the target doesn't have its own IPP implemented (or the -disable-cb
571     // flag is set) then we use the base class (which does nothing).
572     IPP = std::make_unique<mca::InstrPostProcess>(*STI, *MCII);
573   }
574 
575   // Create an instruction builder.
576   mca::InstrBuilder IB(*STI, *MCII, *MRI, MCIA.get(), *IM, CallLatency);
577 
578   // Create a context to control ownership of the pipeline hardware.
579   mca::Context MCA(*MRI, *STI);
580 
581   mca::PipelineOptions PO(MicroOpQueue, DecoderThroughput, DispatchWidth,
582                           RegisterFileSize, LoadQueueSize, StoreQueueSize,
583                           AssumeNoAlias, EnableBottleneckAnalysis);
584 
585   // Number each region in the sequence.
586   unsigned RegionIdx = 0;
587 
588   std::unique_ptr<MCCodeEmitter> MCE(
589       TheTarget->createMCCodeEmitter(*MCII, ACtx));
590   assert(MCE && "Unable to create code emitter!");
591 
592   std::unique_ptr<MCAsmBackend> MAB(TheTarget->createMCAsmBackend(
593       *STI, *MRI, mc::InitMCTargetOptionsFromFlags()));
594   assert(MAB && "Unable to create asm backend!");
595 
596   json::Object JSONOutput;
597   int NonEmptyRegions = 0;
598   for (const std::unique_ptr<mca::AnalysisRegion> &Region : Regions) {
599     // Skip empty code regions.
600     if (Region->empty())
601       continue;
602 
603     IB.clear();
604 
605     // Lower the MCInst sequence into an mca::Instruction sequence.
606     ArrayRef<MCInst> Insts = Region->getInstructions();
607     mca::CodeEmitter CE(*STI, *MAB, *MCE, Insts);
608 
609     IPP->resetState();
610 
611     DenseMap<const MCInst *, SmallVector<mca::Instrument *>> InstToInstruments;
612     SmallVector<std::unique_ptr<mca::Instruction>> LoweredSequence;
613     SmallPtrSet<const MCInst *, 16> DroppedInsts;
614     for (const MCInst &MCI : Insts) {
615       SMLoc Loc = MCI.getLoc();
616       const SmallVector<mca::Instrument *> Instruments =
617           InstrumentRegions.getActiveInstruments(Loc);
618 
619       Expected<std::unique_ptr<mca::Instruction>> Inst =
620           IB.createInstruction(MCI, Instruments);
621       if (!Inst) {
622         if (auto NewE = handleErrors(
623                 Inst.takeError(),
624                 [&IP, &STI](const mca::InstructionError<MCInst> &IE) {
625                   std::string InstructionStr;
626                   raw_string_ostream SS(InstructionStr);
627                   if (shouldSkip(SkipType::LACK_SCHED))
628                     WithColor::warning()
629                         << IE.Message
630                         << ", skipping with -skip-unsupported-instructions, "
631                            "note accuracy will be impacted:\n";
632                   else
633                     WithColor::error()
634                         << IE.Message
635                         << ", use -skip-unsupported-instructions=lack-sched to "
636                            "ignore these on the input.\n";
637                   IP->printInst(&IE.Inst, 0, "", *STI, SS);
638                   SS.flush();
639                   WithColor::note()
640                       << "instruction: " << InstructionStr << '\n';
641                 })) {
642           // Default case.
643           WithColor::error() << toString(std::move(NewE));
644         }
645         if (shouldSkip(SkipType::LACK_SCHED)) {
646           DroppedInsts.insert(&MCI);
647           continue;
648         }
649         return 1;
650       }
651 
652       IPP->postProcessInstruction(Inst.get(), MCI);
653       InstToInstruments.insert({&MCI, Instruments});
654       LoweredSequence.emplace_back(std::move(Inst.get()));
655     }
656 
657     Insts = Region->dropInstructions(DroppedInsts);
658 
659     // Skip empty regions.
660     if (Insts.empty())
661       continue;
662     NonEmptyRegions++;
663 
664     mca::CircularSourceMgr S(LoweredSequence,
665                              PrintInstructionTables ? 1 : Iterations);
666 
667     if (PrintInstructionTables) {
668       //  Create a pipeline, stages, and a printer.
669       auto P = std::make_unique<mca::Pipeline>();
670       P->appendStage(std::make_unique<mca::EntryStage>(S));
671       P->appendStage(std::make_unique<mca::InstructionTables>(SM));
672 
673       mca::PipelinePrinter Printer(*P, *Region, RegionIdx, *STI, PO);
674       if (PrintJson) {
675         Printer.addView(
676             std::make_unique<mca::InstructionView>(*STI, *IP, Insts));
677       }
678 
679       // Create the views for this pipeline, execute, and emit a report.
680       if (PrintInstructionInfoView) {
681         Printer.addView(std::make_unique<mca::InstructionInfoView>(
682             *STI, *MCII, CE, ShowEncoding, Insts, *IP, LoweredSequence,
683             ShowBarriers, *IM, InstToInstruments));
684       }
685       Printer.addView(
686           std::make_unique<mca::ResourcePressureView>(*STI, *IP, Insts));
687 
688       if (!runPipeline(*P))
689         return 1;
690 
691       if (PrintJson) {
692         Printer.printReport(JSONOutput);
693       } else {
694         Printer.printReport(TOF->os());
695       }
696 
697       ++RegionIdx;
698       continue;
699     }
700 
701     // Create the CustomBehaviour object for enforcing Target Specific
702     // behaviours and dependencies that aren't expressed well enough
703     // in the tablegen. CB cannot depend on the list of MCInst or
704     // the source code (but it can depend on the list of
705     // mca::Instruction or any objects that can be reconstructed
706     // from the target information).
707     std::unique_ptr<mca::CustomBehaviour> CB;
708     if (!DisableCustomBehaviour)
709       CB = std::unique_ptr<mca::CustomBehaviour>(
710           TheTarget->createCustomBehaviour(*STI, S, *MCII));
711     if (!CB)
712       // If the target doesn't have its own CB implemented (or the -disable-cb
713       // flag is set) then we use the base class (which does nothing).
714       CB = std::make_unique<mca::CustomBehaviour>(*STI, S, *MCII);
715 
716     // Create a basic pipeline simulating an out-of-order backend.
717     auto P = MCA.createDefaultPipeline(PO, S, *CB);
718 
719     mca::PipelinePrinter Printer(*P, *Region, RegionIdx, *STI, PO);
720 
721     // Targets can define their own custom Views that exist within their
722     // /lib/Target/ directory so that the View can utilize their CustomBehaviour
723     // or other backend symbols / functionality that are not already exposed
724     // through one of the MC-layer classes. These Views will be initialized
725     // using the CustomBehaviour::getViews() variants.
726     // If a target makes a custom View that does not depend on their target
727     // CB or their backend, they should put the View within
728     // /tools/llvm-mca/Views/ instead.
729     if (!DisableCustomBehaviour) {
730       std::vector<std::unique_ptr<mca::View>> CBViews =
731           CB->getStartViews(*IP, Insts);
732       for (auto &CBView : CBViews)
733         Printer.addView(std::move(CBView));
734     }
735 
736     // When we output JSON, we add a view that contains the instructions
737     // and CPU resource information.
738     if (PrintJson) {
739       auto IV = std::make_unique<mca::InstructionView>(*STI, *IP, Insts);
740       Printer.addView(std::move(IV));
741     }
742 
743     if (PrintSummaryView)
744       Printer.addView(
745           std::make_unique<mca::SummaryView>(SM, Insts, DispatchWidth));
746 
747     if (EnableBottleneckAnalysis) {
748       if (!IsOutOfOrder) {
749         WithColor::warning()
750             << "bottleneck analysis is not supported for in-order CPU '" << MCPU
751             << "'.\n";
752       }
753       Printer.addView(std::make_unique<mca::BottleneckAnalysis>(
754           *STI, *IP, Insts, S.getNumIterations()));
755     }
756 
757     if (PrintInstructionInfoView)
758       Printer.addView(std::make_unique<mca::InstructionInfoView>(
759           *STI, *MCII, CE, ShowEncoding, Insts, *IP, LoweredSequence,
760           ShowBarriers, *IM, InstToInstruments));
761 
762     // Fetch custom Views that are to be placed after the InstructionInfoView.
763     // Refer to the comment paired with the CB->getStartViews(*IP, Insts); line
764     // for more info.
765     if (!DisableCustomBehaviour) {
766       std::vector<std::unique_ptr<mca::View>> CBViews =
767           CB->getPostInstrInfoViews(*IP, Insts);
768       for (auto &CBView : CBViews)
769         Printer.addView(std::move(CBView));
770     }
771 
772     if (PrintDispatchStats)
773       Printer.addView(std::make_unique<mca::DispatchStatistics>());
774 
775     if (PrintSchedulerStats)
776       Printer.addView(std::make_unique<mca::SchedulerStatistics>(*STI));
777 
778     if (PrintRetireStats)
779       Printer.addView(std::make_unique<mca::RetireControlUnitStatistics>(SM));
780 
781     if (PrintRegisterFileStats)
782       Printer.addView(std::make_unique<mca::RegisterFileStatistics>(*STI));
783 
784     if (PrintResourcePressureView)
785       Printer.addView(
786           std::make_unique<mca::ResourcePressureView>(*STI, *IP, Insts));
787 
788     if (PrintTimelineView) {
789       unsigned TimelineIterations =
790           TimelineMaxIterations ? TimelineMaxIterations : 10;
791       Printer.addView(std::make_unique<mca::TimelineView>(
792           *STI, *IP, Insts, std::min(TimelineIterations, S.getNumIterations()),
793           TimelineMaxCycles));
794     }
795 
796     // Fetch custom Views that are to be placed after all other Views.
797     // Refer to the comment paired with the CB->getStartViews(*IP, Insts); line
798     // for more info.
799     if (!DisableCustomBehaviour) {
800       std::vector<std::unique_ptr<mca::View>> CBViews =
801           CB->getEndViews(*IP, Insts);
802       for (auto &CBView : CBViews)
803         Printer.addView(std::move(CBView));
804     }
805 
806     if (!runPipeline(*P))
807       return 1;
808 
809     if (PrintJson) {
810       Printer.printReport(JSONOutput);
811     } else {
812       Printer.printReport(TOF->os());
813     }
814 
815     ++RegionIdx;
816   }
817 
818   if (NonEmptyRegions == 0) {
819     WithColor::error() << "no assembly instructions found.\n";
820     return 1;
821   }
822 
823   if (PrintJson)
824     TOF->os() << formatv("{0:2}", json::Value(std::move(JSONOutput))) << "\n";
825 
826   TOF->keep();
827   return 0;
828 }
829