xref: /freebsd/contrib/llvm-project/llvm/tools/llvm-mca/llvm-mca.cpp (revision 0ad011ececb978e22a9bff2acf76633b094f1ff6)
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<bool>
139     PrintRegisterFileStats("register-file-stats",
140                            cl::desc("Print register file statistics"),
141                            cl::cat(ViewOptions), cl::init(false));
142 
143 static cl::opt<bool> PrintDispatchStats("dispatch-stats",
144                                         cl::desc("Print dispatch statistics"),
145                                         cl::cat(ViewOptions), cl::init(false));
146 
147 static cl::opt<bool>
148     PrintSummaryView("summary-view", cl::Hidden,
149                      cl::desc("Print summary view (enabled by default)"),
150                      cl::cat(ViewOptions), cl::init(true));
151 
152 static cl::opt<bool> PrintSchedulerStats("scheduler-stats",
153                                          cl::desc("Print scheduler statistics"),
154                                          cl::cat(ViewOptions), cl::init(false));
155 
156 static cl::opt<bool>
157     PrintRetireStats("retire-stats",
158                      cl::desc("Print retire control unit statistics"),
159                      cl::cat(ViewOptions), cl::init(false));
160 
161 static cl::opt<bool> PrintResourcePressureView(
162     "resource-pressure",
163     cl::desc("Print the resource pressure view (enabled by default)"),
164     cl::cat(ViewOptions), cl::init(true));
165 
166 static cl::opt<bool> PrintTimelineView("timeline",
167                                        cl::desc("Print the timeline view"),
168                                        cl::cat(ViewOptions), cl::init(false));
169 
170 static cl::opt<unsigned> TimelineMaxIterations(
171     "timeline-max-iterations",
172     cl::desc("Maximum number of iterations to print in timeline view"),
173     cl::cat(ViewOptions), cl::init(0));
174 
175 static cl::opt<unsigned>
176     TimelineMaxCycles("timeline-max-cycles",
177                       cl::desc("Maximum number of cycles in the timeline view, "
178                                "or 0 for unlimited. Defaults to 80 cycles"),
179                       cl::cat(ViewOptions), cl::init(80));
180 
181 static cl::opt<bool>
182     AssumeNoAlias("noalias",
183                   cl::desc("If set, assume that loads and stores do not alias"),
184                   cl::cat(ToolOptions), cl::init(true));
185 
186 static cl::opt<unsigned> LoadQueueSize("lqueue",
187                                        cl::desc("Size of the load queue"),
188                                        cl::cat(ToolOptions), cl::init(0));
189 
190 static cl::opt<unsigned> StoreQueueSize("squeue",
191                                         cl::desc("Size of the store queue"),
192                                         cl::cat(ToolOptions), cl::init(0));
193 
194 static cl::opt<bool>
195     PrintInstructionTables("instruction-tables",
196                            cl::desc("Print instruction tables"),
197                            cl::cat(ToolOptions), cl::init(false));
198 
199 static cl::opt<bool> PrintInstructionInfoView(
200     "instruction-info",
201     cl::desc("Print the instruction info view (enabled by default)"),
202     cl::cat(ViewOptions), cl::init(true));
203 
204 static cl::opt<bool> EnableAllStats("all-stats",
205                                     cl::desc("Print all hardware statistics"),
206                                     cl::cat(ViewOptions), cl::init(false));
207 
208 static cl::opt<bool>
209     EnableAllViews("all-views",
210                    cl::desc("Print all views including hardware statistics"),
211                    cl::cat(ViewOptions), cl::init(false));
212 
213 static cl::opt<bool> EnableBottleneckAnalysis(
214     "bottleneck-analysis",
215     cl::desc("Enable bottleneck analysis (disabled by default)"),
216     cl::cat(ViewOptions), cl::init(false));
217 
218 static cl::opt<bool> ShowEncoding(
219     "show-encoding",
220     cl::desc("Print encoding information in the instruction info view"),
221     cl::cat(ViewOptions), cl::init(false));
222 
223 static cl::opt<bool> ShowBarriers(
224     "show-barriers",
225     cl::desc("Print memory barrier information in the instruction info view"),
226     cl::cat(ViewOptions), cl::init(false));
227 
228 static cl::opt<bool> DisableCustomBehaviour(
229     "disable-cb",
230     cl::desc(
231         "Disable custom behaviour (use the default class which does nothing)."),
232     cl::cat(ViewOptions), cl::init(false));
233 
234 static cl::opt<bool> DisableInstrumentManager(
235     "disable-im",
236     cl::desc("Disable instrumentation manager (use the default class which "
237              "ignores instruments.)."),
238     cl::cat(ViewOptions), cl::init(false));
239 
240 namespace {
241 
242 const Target *getTarget(const char *ProgName) {
243   if (TripleName.empty())
244     TripleName = Triple::normalize(sys::getDefaultTargetTriple());
245   Triple TheTriple(TripleName);
246 
247   // Get the target specific parser.
248   std::string Error;
249   const Target *TheTarget =
250       TargetRegistry::lookupTarget(ArchName, TheTriple, Error);
251   if (!TheTarget) {
252     errs() << ProgName << ": " << Error;
253     return nullptr;
254   }
255 
256   // Update TripleName with the updated triple from the target lookup.
257   TripleName = TheTriple.str();
258 
259   // Return the found target.
260   return TheTarget;
261 }
262 
263 ErrorOr<std::unique_ptr<ToolOutputFile>> getOutputStream() {
264   if (OutputFilename == "")
265     OutputFilename = "-";
266   std::error_code EC;
267   auto Out = std::make_unique<ToolOutputFile>(OutputFilename, EC,
268                                               sys::fs::OF_TextWithCRLF);
269   if (!EC)
270     return std::move(Out);
271   return EC;
272 }
273 } // end of anonymous namespace
274 
275 static void processOptionImpl(cl::opt<bool> &O, const cl::opt<bool> &Default) {
276   if (!O.getNumOccurrences() || O.getPosition() < Default.getPosition())
277     O = Default.getValue();
278 }
279 
280 static void processViewOptions(bool IsOutOfOrder) {
281   if (!EnableAllViews.getNumOccurrences() &&
282       !EnableAllStats.getNumOccurrences())
283     return;
284 
285   if (EnableAllViews.getNumOccurrences()) {
286     processOptionImpl(PrintSummaryView, EnableAllViews);
287     if (IsOutOfOrder)
288       processOptionImpl(EnableBottleneckAnalysis, EnableAllViews);
289     processOptionImpl(PrintResourcePressureView, EnableAllViews);
290     processOptionImpl(PrintTimelineView, EnableAllViews);
291     processOptionImpl(PrintInstructionInfoView, EnableAllViews);
292   }
293 
294   const cl::opt<bool> &Default =
295       EnableAllViews.getPosition() < EnableAllStats.getPosition()
296           ? EnableAllStats
297           : EnableAllViews;
298   processOptionImpl(PrintRegisterFileStats, Default);
299   processOptionImpl(PrintDispatchStats, Default);
300   processOptionImpl(PrintSchedulerStats, Default);
301   if (IsOutOfOrder)
302     processOptionImpl(PrintRetireStats, Default);
303 }
304 
305 // Returns true on success.
306 static bool runPipeline(mca::Pipeline &P) {
307   // Handle pipeline errors here.
308   Expected<unsigned> Cycles = P.run();
309   if (!Cycles) {
310     WithColor::error() << toString(Cycles.takeError());
311     return false;
312   }
313   return true;
314 }
315 
316 int main(int argc, char **argv) {
317   InitLLVM X(argc, argv);
318 
319   // Initialize targets and assembly parsers.
320   InitializeAllTargetInfos();
321   InitializeAllTargetMCs();
322   InitializeAllAsmParsers();
323   InitializeAllTargetMCAs();
324 
325   // Register the Target and CPU printer for --version.
326   cl::AddExtraVersionPrinter(sys::printDefaultTargetAndDetectedCPU);
327 
328   // Enable printing of available targets when flag --version is specified.
329   cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
330 
331   cl::HideUnrelatedOptions({&ToolOptions, &ViewOptions});
332 
333   // Parse flags and initialize target options.
334   cl::ParseCommandLineOptions(argc, argv,
335                               "llvm machine code performance analyzer.\n");
336 
337   // Get the target from the triple. If a triple is not specified, then select
338   // the default triple for the host. If the triple doesn't correspond to any
339   // registered target, then exit with an error message.
340   const char *ProgName = argv[0];
341   const Target *TheTarget = getTarget(ProgName);
342   if (!TheTarget)
343     return 1;
344 
345   // GetTarget() may replaced TripleName with a default triple.
346   // For safety, reconstruct the Triple object.
347   Triple TheTriple(TripleName);
348 
349   ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr =
350       MemoryBuffer::getFileOrSTDIN(InputFilename);
351   if (std::error_code EC = BufferPtr.getError()) {
352     WithColor::error() << InputFilename << ": " << EC.message() << '\n';
353     return 1;
354   }
355 
356   if (MCPU == "native")
357     MCPU = std::string(llvm::sys::getHostCPUName());
358 
359   // Package up features to be passed to target/subtarget
360   std::string FeaturesStr;
361   if (MATTRS.size()) {
362     SubtargetFeatures Features;
363     for (std::string &MAttr : MATTRS)
364       Features.AddFeature(MAttr);
365     FeaturesStr = Features.getString();
366   }
367 
368   std::unique_ptr<MCSubtargetInfo> STI(
369       TheTarget->createMCSubtargetInfo(TripleName, MCPU, FeaturesStr));
370   assert(STI && "Unable to create subtarget info!");
371   if (!STI->isCPUStringValid(MCPU))
372     return 1;
373 
374   if (!STI->getSchedModel().hasInstrSchedModel()) {
375     WithColor::error()
376         << "unable to find instruction-level scheduling information for"
377         << " target triple '" << TheTriple.normalize() << "' and cpu '" << MCPU
378         << "'.\n";
379 
380     if (STI->getSchedModel().InstrItineraries)
381       WithColor::note()
382           << "cpu '" << MCPU << "' provides itineraries. However, "
383           << "instruction itineraries are currently unsupported.\n";
384     return 1;
385   }
386 
387   // Apply overrides to llvm-mca specific options.
388   bool IsOutOfOrder = STI->getSchedModel().isOutOfOrder();
389   processViewOptions(IsOutOfOrder);
390 
391   std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
392   assert(MRI && "Unable to create target register info!");
393 
394   MCTargetOptions MCOptions = mc::InitMCTargetOptionsFromFlags();
395   std::unique_ptr<MCAsmInfo> MAI(
396       TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
397   assert(MAI && "Unable to create target asm info!");
398 
399   SourceMgr SrcMgr;
400 
401   // Tell SrcMgr about this buffer, which is what the parser will pick up.
402   SrcMgr.AddNewSourceBuffer(std::move(*BufferPtr), SMLoc());
403 
404   std::unique_ptr<buffer_ostream> BOS;
405 
406   std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
407   assert(MCII && "Unable to create instruction info!");
408 
409   std::unique_ptr<MCInstrAnalysis> MCIA(
410       TheTarget->createMCInstrAnalysis(MCII.get()));
411 
412   // Need to initialize an MCInstPrinter as it is
413   // required for initializing the MCTargetStreamer
414   // which needs to happen within the CRG.parseAnalysisRegions() call below.
415   // Without an MCTargetStreamer, certain assembly directives can trigger a
416   // segfault. (For example, the .cv_fpo_proc directive on x86 will segfault if
417   // we don't initialize the MCTargetStreamer.)
418   unsigned IPtempOutputAsmVariant =
419       OutputAsmVariant == -1 ? 0 : OutputAsmVariant;
420   std::unique_ptr<MCInstPrinter> IPtemp(TheTarget->createMCInstPrinter(
421       Triple(TripleName), IPtempOutputAsmVariant, *MAI, *MCII, *MRI));
422   if (!IPtemp) {
423     WithColor::error()
424         << "unable to create instruction printer for target triple '"
425         << TheTriple.normalize() << "' with assembly variant "
426         << IPtempOutputAsmVariant << ".\n";
427     return 1;
428   }
429 
430   // Parse the input and create CodeRegions that llvm-mca can analyze.
431   MCContext ACtx(TheTriple, MAI.get(), MRI.get(), STI.get(), &SrcMgr);
432   std::unique_ptr<MCObjectFileInfo> AMOFI(
433       TheTarget->createMCObjectFileInfo(ACtx, /*PIC=*/false));
434   ACtx.setObjectFileInfo(AMOFI.get());
435   mca::AsmAnalysisRegionGenerator CRG(*TheTarget, SrcMgr, ACtx, *MAI, *STI,
436                                       *MCII);
437   Expected<const mca::AnalysisRegions &> RegionsOrErr =
438       CRG.parseAnalysisRegions(std::move(IPtemp));
439   if (!RegionsOrErr) {
440     if (auto Err =
441             handleErrors(RegionsOrErr.takeError(), [](const StringError &E) {
442               WithColor::error() << E.getMessage() << '\n';
443             })) {
444       // Default case.
445       WithColor::error() << toString(std::move(Err)) << '\n';
446     }
447     return 1;
448   }
449   const mca::AnalysisRegions &Regions = *RegionsOrErr;
450 
451   // Early exit if errors were found by the code region parsing logic.
452   if (!Regions.isValid())
453     return 1;
454 
455   if (Regions.empty()) {
456     WithColor::error() << "no assembly instructions found.\n";
457     return 1;
458   }
459 
460   std::unique_ptr<mca::InstrumentManager> IM;
461   if (!DisableInstrumentManager) {
462     IM = std::unique_ptr<mca::InstrumentManager>(
463         TheTarget->createInstrumentManager(*STI, *MCII));
464   }
465   if (!IM) {
466     // If the target doesn't have its own IM implemented (or the -disable-cb
467     // flag is set) then we use the base class (which does nothing).
468     IM = std::make_unique<mca::InstrumentManager>(*STI, *MCII);
469   }
470 
471   // Parse the input and create InstrumentRegion that llvm-mca
472   // can use to improve analysis.
473   MCContext ICtx(TheTriple, MAI.get(), MRI.get(), STI.get(), &SrcMgr);
474   std::unique_ptr<MCObjectFileInfo> IMOFI(
475       TheTarget->createMCObjectFileInfo(ICtx, /*PIC=*/false));
476   ICtx.setObjectFileInfo(IMOFI.get());
477   mca::AsmInstrumentRegionGenerator IRG(*TheTarget, SrcMgr, ICtx, *MAI, *STI,
478                                         *MCII, *IM);
479   Expected<const mca::InstrumentRegions &> InstrumentRegionsOrErr =
480       IRG.parseInstrumentRegions(std::move(IPtemp));
481   if (!InstrumentRegionsOrErr) {
482     if (auto Err = handleErrors(InstrumentRegionsOrErr.takeError(),
483                                 [](const StringError &E) {
484                                   WithColor::error() << E.getMessage() << '\n';
485                                 })) {
486       // Default case.
487       WithColor::error() << toString(std::move(Err)) << '\n';
488     }
489     return 1;
490   }
491   const mca::InstrumentRegions &InstrumentRegions = *InstrumentRegionsOrErr;
492 
493   // Early exit if errors were found by the instrumentation parsing logic.
494   if (!InstrumentRegions.isValid())
495     return 1;
496 
497   // Now initialize the output file.
498   auto OF = getOutputStream();
499   if (std::error_code EC = OF.getError()) {
500     WithColor::error() << EC.message() << '\n';
501     return 1;
502   }
503 
504   unsigned AssemblerDialect = CRG.getAssemblerDialect();
505   if (OutputAsmVariant >= 0)
506     AssemblerDialect = static_cast<unsigned>(OutputAsmVariant);
507   std::unique_ptr<MCInstPrinter> IP(TheTarget->createMCInstPrinter(
508       Triple(TripleName), AssemblerDialect, *MAI, *MCII, *MRI));
509   if (!IP) {
510     WithColor::error()
511         << "unable to create instruction printer for target triple '"
512         << TheTriple.normalize() << "' with assembly variant "
513         << AssemblerDialect << ".\n";
514     return 1;
515   }
516 
517   // Set the display preference for hex vs. decimal immediates.
518   IP->setPrintImmHex(PrintImmHex);
519 
520   std::unique_ptr<ToolOutputFile> TOF = std::move(*OF);
521 
522   const MCSchedModel &SM = STI->getSchedModel();
523 
524   std::unique_ptr<mca::InstrPostProcess> IPP;
525   if (!DisableCustomBehaviour) {
526     // TODO: It may be a good idea to separate CB and IPP so that they can
527     // be used independently of each other. What I mean by this is to add
528     // an extra command-line arg --disable-ipp so that CB and IPP can be
529     // toggled without needing to toggle both of them together.
530     IPP = std::unique_ptr<mca::InstrPostProcess>(
531         TheTarget->createInstrPostProcess(*STI, *MCII));
532   }
533   if (!IPP) {
534     // If the target doesn't have its own IPP implemented (or the -disable-cb
535     // flag is set) then we use the base class (which does nothing).
536     IPP = std::make_unique<mca::InstrPostProcess>(*STI, *MCII);
537   }
538 
539   // Create an instruction builder.
540   mca::InstrBuilder IB(*STI, *MCII, *MRI, MCIA.get(), *IM);
541 
542   // Create a context to control ownership of the pipeline hardware.
543   mca::Context MCA(*MRI, *STI);
544 
545   mca::PipelineOptions PO(MicroOpQueue, DecoderThroughput, DispatchWidth,
546                           RegisterFileSize, LoadQueueSize, StoreQueueSize,
547                           AssumeNoAlias, EnableBottleneckAnalysis);
548 
549   // Number each region in the sequence.
550   unsigned RegionIdx = 0;
551 
552   std::unique_ptr<MCCodeEmitter> MCE(
553       TheTarget->createMCCodeEmitter(*MCII, ACtx));
554   assert(MCE && "Unable to create code emitter!");
555 
556   std::unique_ptr<MCAsmBackend> MAB(TheTarget->createMCAsmBackend(
557       *STI, *MRI, mc::InitMCTargetOptionsFromFlags()));
558   assert(MAB && "Unable to create asm backend!");
559 
560   json::Object JSONOutput;
561   for (const std::unique_ptr<mca::AnalysisRegion> &Region : Regions) {
562     // Skip empty code regions.
563     if (Region->empty())
564       continue;
565 
566     IB.clear();
567 
568     // Lower the MCInst sequence into an mca::Instruction sequence.
569     ArrayRef<MCInst> Insts = Region->getInstructions();
570     mca::CodeEmitter CE(*STI, *MAB, *MCE, Insts);
571 
572     IPP->resetState();
573 
574     DenseMap<const MCInst *, SmallVector<mca::Instrument *>>
575         InstToInstruments;
576     SmallVector<std::unique_ptr<mca::Instruction>> LoweredSequence;
577     for (const MCInst &MCI : Insts) {
578       SMLoc Loc = MCI.getLoc();
579       const SmallVector<mca::Instrument *> Instruments =
580           InstrumentRegions.getActiveInstruments(Loc);
581       InstToInstruments.insert({&MCI, Instruments});
582 
583       Expected<std::unique_ptr<mca::Instruction>> Inst =
584           IB.createInstruction(MCI, Instruments);
585       if (!Inst) {
586         if (auto NewE = handleErrors(
587                 Inst.takeError(),
588                 [&IP, &STI](const mca::InstructionError<MCInst> &IE) {
589                   std::string InstructionStr;
590                   raw_string_ostream SS(InstructionStr);
591                   WithColor::error() << IE.Message << '\n';
592                   IP->printInst(&IE.Inst, 0, "", *STI, SS);
593                   SS.flush();
594                   WithColor::note()
595                       << "instruction: " << InstructionStr << '\n';
596                 })) {
597           // Default case.
598           WithColor::error() << toString(std::move(NewE));
599         }
600         return 1;
601       }
602 
603       IPP->postProcessInstruction(Inst.get(), MCI);
604 
605       LoweredSequence.emplace_back(std::move(Inst.get()));
606     }
607 
608     mca::CircularSourceMgr S(LoweredSequence,
609                              PrintInstructionTables ? 1 : Iterations);
610 
611     if (PrintInstructionTables) {
612       //  Create a pipeline, stages, and a printer.
613       auto P = std::make_unique<mca::Pipeline>();
614       P->appendStage(std::make_unique<mca::EntryStage>(S));
615       P->appendStage(std::make_unique<mca::InstructionTables>(SM));
616 
617       mca::PipelinePrinter Printer(*P, *Region, RegionIdx, *STI, PO);
618       if (PrintJson) {
619         Printer.addView(
620             std::make_unique<mca::InstructionView>(*STI, *IP, Insts));
621       }
622 
623       // Create the views for this pipeline, execute, and emit a report.
624       if (PrintInstructionInfoView) {
625         Printer.addView(std::make_unique<mca::InstructionInfoView>(
626             *STI, *MCII, CE, ShowEncoding, Insts, *IP, LoweredSequence,
627             ShowBarriers, *IM, InstToInstruments));
628       }
629       Printer.addView(
630           std::make_unique<mca::ResourcePressureView>(*STI, *IP, Insts));
631 
632       if (!runPipeline(*P))
633         return 1;
634 
635       if (PrintJson) {
636         Printer.printReport(JSONOutput);
637       } else {
638         Printer.printReport(TOF->os());
639       }
640 
641       ++RegionIdx;
642       continue;
643     }
644 
645     // Create the CustomBehaviour object for enforcing Target Specific
646     // behaviours and dependencies that aren't expressed well enough
647     // in the tablegen. CB cannot depend on the list of MCInst or
648     // the source code (but it can depend on the list of
649     // mca::Instruction or any objects that can be reconstructed
650     // from the target information).
651     std::unique_ptr<mca::CustomBehaviour> CB;
652     if (!DisableCustomBehaviour)
653       CB = std::unique_ptr<mca::CustomBehaviour>(
654           TheTarget->createCustomBehaviour(*STI, S, *MCII));
655     if (!CB)
656       // If the target doesn't have its own CB implemented (or the -disable-cb
657       // flag is set) then we use the base class (which does nothing).
658       CB = std::make_unique<mca::CustomBehaviour>(*STI, S, *MCII);
659 
660     // Create a basic pipeline simulating an out-of-order backend.
661     auto P = MCA.createDefaultPipeline(PO, S, *CB);
662 
663     mca::PipelinePrinter Printer(*P, *Region, RegionIdx, *STI, PO);
664 
665     // Targets can define their own custom Views that exist within their
666     // /lib/Target/ directory so that the View can utilize their CustomBehaviour
667     // or other backend symbols / functionality that are not already exposed
668     // through one of the MC-layer classes. These Views will be initialized
669     // using the CustomBehaviour::getViews() variants.
670     // If a target makes a custom View that does not depend on their target
671     // CB or their backend, they should put the View within
672     // /tools/llvm-mca/Views/ instead.
673     if (!DisableCustomBehaviour) {
674       std::vector<std::unique_ptr<mca::View>> CBViews =
675           CB->getStartViews(*IP, Insts);
676       for (auto &CBView : CBViews)
677         Printer.addView(std::move(CBView));
678     }
679 
680     // When we output JSON, we add a view that contains the instructions
681     // and CPU resource information.
682     if (PrintJson) {
683       auto IV = std::make_unique<mca::InstructionView>(*STI, *IP, Insts);
684       Printer.addView(std::move(IV));
685     }
686 
687     if (PrintSummaryView)
688       Printer.addView(
689           std::make_unique<mca::SummaryView>(SM, Insts, DispatchWidth));
690 
691     if (EnableBottleneckAnalysis) {
692       if (!IsOutOfOrder) {
693         WithColor::warning()
694             << "bottleneck analysis is not supported for in-order CPU '" << MCPU
695             << "'.\n";
696       }
697       Printer.addView(std::make_unique<mca::BottleneckAnalysis>(
698           *STI, *IP, Insts, S.getNumIterations()));
699     }
700 
701     if (PrintInstructionInfoView)
702       Printer.addView(std::make_unique<mca::InstructionInfoView>(
703           *STI, *MCII, CE, ShowEncoding, Insts, *IP, LoweredSequence,
704           ShowBarriers, *IM, InstToInstruments));
705 
706     // Fetch custom Views that are to be placed after the InstructionInfoView.
707     // Refer to the comment paired with the CB->getStartViews(*IP, Insts); line
708     // for more info.
709     if (!DisableCustomBehaviour) {
710       std::vector<std::unique_ptr<mca::View>> CBViews =
711           CB->getPostInstrInfoViews(*IP, Insts);
712       for (auto &CBView : CBViews)
713         Printer.addView(std::move(CBView));
714     }
715 
716     if (PrintDispatchStats)
717       Printer.addView(std::make_unique<mca::DispatchStatistics>());
718 
719     if (PrintSchedulerStats)
720       Printer.addView(std::make_unique<mca::SchedulerStatistics>(*STI));
721 
722     if (PrintRetireStats)
723       Printer.addView(std::make_unique<mca::RetireControlUnitStatistics>(SM));
724 
725     if (PrintRegisterFileStats)
726       Printer.addView(std::make_unique<mca::RegisterFileStatistics>(*STI));
727 
728     if (PrintResourcePressureView)
729       Printer.addView(
730           std::make_unique<mca::ResourcePressureView>(*STI, *IP, Insts));
731 
732     if (PrintTimelineView) {
733       unsigned TimelineIterations =
734           TimelineMaxIterations ? TimelineMaxIterations : 10;
735       Printer.addView(std::make_unique<mca::TimelineView>(
736           *STI, *IP, Insts, std::min(TimelineIterations, S.getNumIterations()),
737           TimelineMaxCycles));
738     }
739 
740     // Fetch custom Views that are to be placed after all other Views.
741     // Refer to the comment paired with the CB->getStartViews(*IP, Insts); line
742     // for more info.
743     if (!DisableCustomBehaviour) {
744       std::vector<std::unique_ptr<mca::View>> CBViews =
745           CB->getEndViews(*IP, Insts);
746       for (auto &CBView : CBViews)
747         Printer.addView(std::move(CBView));
748     }
749 
750     if (!runPipeline(*P))
751       return 1;
752 
753     if (PrintJson) {
754       Printer.printReport(JSONOutput);
755     } else {
756       Printer.printReport(TOF->os());
757     }
758 
759     ++RegionIdx;
760   }
761 
762   if (PrintJson)
763     TOF->os() << formatv("{0:2}", json::Value(std::move(JSONOutput))) << "\n";
764 
765   TOF->keep();
766   return 0;
767 }
768