1 //===- InlineAdvisor.cpp - analysis pass implementation -------------------===//
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 file implements InlineAdvisorAnalysis and DefaultInlineAdvisor, and
10 // related types.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Analysis/InlineAdvisor.h"
15 #include "llvm/ADT/Statistic.h"
16 #include "llvm/ADT/StringExtras.h"
17 #include "llvm/Analysis/AssumptionCache.h"
18 #include "llvm/Analysis/InlineCost.h"
19 #include "llvm/Analysis/OptimizationRemarkEmitter.h"
20 #include "llvm/Analysis/ProfileSummaryInfo.h"
21 #include "llvm/Analysis/ReplayInlineAdvisor.h"
22 #include "llvm/Analysis/TargetLibraryInfo.h"
23 #include "llvm/Analysis/TargetTransformInfo.h"
24 #include "llvm/Analysis/Utils/ImportedFunctionsInliningStatistics.h"
25 #include "llvm/IR/DebugInfoMetadata.h"
26 #include "llvm/IR/PassManager.h"
27 #include "llvm/Support/CommandLine.h"
28 #include "llvm/Support/raw_ostream.h"
29 
30 using namespace llvm;
31 #define DEBUG_TYPE "inline"
32 #ifdef LLVM_HAVE_TF_AOT_INLINERSIZEMODEL
33 #define LLVM_HAVE_TF_AOT
34 #endif
35 
36 // This weirdly named statistic tracks the number of times that, when attempting
37 // to inline a function A into B, we analyze the callers of B in order to see
38 // if those would be more profitable and blocked inline steps.
39 STATISTIC(NumCallerCallersAnalyzed, "Number of caller-callers analyzed");
40 
41 /// Flag to add inline messages as callsite attributes 'inline-remark'.
42 static cl::opt<bool>
43     InlineRemarkAttribute("inline-remark-attribute", cl::init(false),
44                           cl::Hidden,
45                           cl::desc("Enable adding inline-remark attribute to"
46                                    " callsites processed by inliner but decided"
47                                    " to be not inlined"));
48 
49 static cl::opt<bool> EnableInlineDeferral("inline-deferral", cl::init(false),
50                                           cl::Hidden,
51                                           cl::desc("Enable deferred inlining"));
52 
53 // An integer used to limit the cost of inline deferral.  The default negative
54 // number tells shouldBeDeferred to only take the secondary cost into account.
55 static cl::opt<int>
56     InlineDeferralScale("inline-deferral-scale",
57                         cl::desc("Scale to limit the cost of inline deferral"),
58                         cl::init(2), cl::Hidden);
59 
60 static cl::opt<bool>
61     AnnotateInlinePhase("annotate-inline-phase", cl::Hidden, cl::init(false),
62                         cl::desc("If true, annotate inline advisor remarks "
63                                  "with LTO and pass information."));
64 
65 namespace llvm {
66 extern cl::opt<InlinerFunctionImportStatsOpts> InlinerFunctionImportStats;
67 }
68 
69 namespace {
70 using namespace llvm::ore;
71 class MandatoryInlineAdvice : public InlineAdvice {
72 public:
73   MandatoryInlineAdvice(InlineAdvisor *Advisor, CallBase &CB,
74                         OptimizationRemarkEmitter &ORE,
75                         bool IsInliningMandatory)
76       : InlineAdvice(Advisor, CB, ORE, IsInliningMandatory) {}
77 
78 private:
79   void recordInliningWithCalleeDeletedImpl() override { recordInliningImpl(); }
80 
81   void recordInliningImpl() override {
82     if (IsInliningRecommended)
83       emitInlinedInto(ORE, DLoc, Block, *Callee, *Caller, IsInliningRecommended,
84                       [&](OptimizationRemark &Remark) {
85                         Remark << ": always inline attribute";
86                       });
87   }
88 
89   void recordUnsuccessfulInliningImpl(const InlineResult &Result) override {
90     if (IsInliningRecommended)
91       ORE.emit([&]() {
92         return OptimizationRemarkMissed(Advisor->getAnnotatedInlinePassName(),
93                                         "NotInlined", DLoc, Block)
94                << "'" << NV("Callee", Callee) << "' is not AlwaysInline into '"
95                << NV("Caller", Caller)
96                << "': " << NV("Reason", Result.getFailureReason());
97       });
98   }
99 
100   void recordUnattemptedInliningImpl() override {
101     assert(!IsInliningRecommended && "Expected to attempt inlining");
102   }
103 };
104 } // namespace
105 
106 void DefaultInlineAdvice::recordUnsuccessfulInliningImpl(
107     const InlineResult &Result) {
108   using namespace ore;
109   llvm::setInlineRemark(*OriginalCB, std::string(Result.getFailureReason()) +
110                                          "; " + inlineCostStr(*OIC));
111   ORE.emit([&]() {
112     return OptimizationRemarkMissed(Advisor->getAnnotatedInlinePassName(),
113                                     "NotInlined", DLoc, Block)
114            << "'" << NV("Callee", Callee) << "' is not inlined into '"
115            << NV("Caller", Caller)
116            << "': " << NV("Reason", Result.getFailureReason());
117   });
118 }
119 
120 void DefaultInlineAdvice::recordInliningWithCalleeDeletedImpl() {
121   if (EmitRemarks)
122     emitInlinedIntoBasedOnCost(ORE, DLoc, Block, *Callee, *Caller, *OIC,
123                                /* ForProfileContext= */ false,
124                                Advisor->getAnnotatedInlinePassName());
125 }
126 
127 void DefaultInlineAdvice::recordInliningImpl() {
128   if (EmitRemarks)
129     emitInlinedIntoBasedOnCost(ORE, DLoc, Block, *Callee, *Caller, *OIC,
130                                /* ForProfileContext= */ false,
131                                Advisor->getAnnotatedInlinePassName());
132 }
133 
134 std::optional<llvm::InlineCost> static getDefaultInlineAdvice(
135     CallBase &CB, FunctionAnalysisManager &FAM, const InlineParams &Params) {
136   Function &Caller = *CB.getCaller();
137   ProfileSummaryInfo *PSI =
138       FAM.getResult<ModuleAnalysisManagerFunctionProxy>(Caller)
139           .getCachedResult<ProfileSummaryAnalysis>(
140               *CB.getParent()->getParent()->getParent());
141 
142   auto &ORE = FAM.getResult<OptimizationRemarkEmitterAnalysis>(Caller);
143   auto GetAssumptionCache = [&](Function &F) -> AssumptionCache & {
144     return FAM.getResult<AssumptionAnalysis>(F);
145   };
146   auto GetBFI = [&](Function &F) -> BlockFrequencyInfo & {
147     return FAM.getResult<BlockFrequencyAnalysis>(F);
148   };
149   auto GetTLI = [&](Function &F) -> const TargetLibraryInfo & {
150     return FAM.getResult<TargetLibraryAnalysis>(F);
151   };
152 
153   auto GetInlineCost = [&](CallBase &CB) {
154     Function &Callee = *CB.getCalledFunction();
155     auto &CalleeTTI = FAM.getResult<TargetIRAnalysis>(Callee);
156     bool RemarksEnabled =
157         Callee.getContext().getDiagHandlerPtr()->isMissedOptRemarkEnabled(
158             DEBUG_TYPE);
159     return getInlineCost(CB, Params, CalleeTTI, GetAssumptionCache, GetTLI,
160                          GetBFI, PSI, RemarksEnabled ? &ORE : nullptr);
161   };
162   return llvm::shouldInline(
163       CB, GetInlineCost, ORE,
164       Params.EnableDeferral.value_or(EnableInlineDeferral));
165 }
166 
167 std::unique_ptr<InlineAdvice>
168 DefaultInlineAdvisor::getAdviceImpl(CallBase &CB) {
169   auto OIC = getDefaultInlineAdvice(CB, FAM, Params);
170   return std::make_unique<DefaultInlineAdvice>(
171       this, CB, OIC,
172       FAM.getResult<OptimizationRemarkEmitterAnalysis>(*CB.getCaller()));
173 }
174 
175 InlineAdvice::InlineAdvice(InlineAdvisor *Advisor, CallBase &CB,
176                            OptimizationRemarkEmitter &ORE,
177                            bool IsInliningRecommended)
178     : Advisor(Advisor), Caller(CB.getCaller()), Callee(CB.getCalledFunction()),
179       DLoc(CB.getDebugLoc()), Block(CB.getParent()), ORE(ORE),
180       IsInliningRecommended(IsInliningRecommended) {}
181 
182 void InlineAdvice::recordInlineStatsIfNeeded() {
183   if (Advisor->ImportedFunctionsStats)
184     Advisor->ImportedFunctionsStats->recordInline(*Caller, *Callee);
185 }
186 
187 void InlineAdvice::recordInlining() {
188   markRecorded();
189   recordInlineStatsIfNeeded();
190   recordInliningImpl();
191 }
192 
193 void InlineAdvice::recordInliningWithCalleeDeleted() {
194   markRecorded();
195   recordInlineStatsIfNeeded();
196   recordInliningWithCalleeDeletedImpl();
197 }
198 
199 AnalysisKey InlineAdvisorAnalysis::Key;
200 AnalysisKey PluginInlineAdvisorAnalysis::Key;
201 bool PluginInlineAdvisorAnalysis::HasBeenRegistered = false;
202 
203 bool InlineAdvisorAnalysis::Result::tryCreate(
204     InlineParams Params, InliningAdvisorMode Mode,
205     const ReplayInlinerSettings &ReplaySettings, InlineContext IC) {
206   auto &FAM = MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
207   if (PluginInlineAdvisorAnalysis::HasBeenRegistered) {
208     auto &DA = MAM.getResult<PluginInlineAdvisorAnalysis>(M);
209     Advisor.reset(DA.Factory(M, FAM, Params, IC));
210     return !!Advisor;
211   }
212   auto GetDefaultAdvice = [&FAM, Params](CallBase &CB) {
213     auto OIC = getDefaultInlineAdvice(CB, FAM, Params);
214     return OIC.has_value();
215   };
216   switch (Mode) {
217   case InliningAdvisorMode::Default:
218     LLVM_DEBUG(dbgs() << "Using default inliner heuristic.\n");
219     Advisor.reset(new DefaultInlineAdvisor(M, FAM, Params, IC));
220     // Restrict replay to default advisor, ML advisors are stateful so
221     // replay will need augmentations to interleave with them correctly.
222     if (!ReplaySettings.ReplayFile.empty()) {
223       Advisor = llvm::getReplayInlineAdvisor(M, FAM, M.getContext(),
224                                              std::move(Advisor), ReplaySettings,
225                                              /* EmitRemarks =*/true, IC);
226     }
227     break;
228   case InliningAdvisorMode::Development:
229 #ifdef LLVM_HAVE_TFLITE
230     LLVM_DEBUG(dbgs() << "Using development-mode inliner policy.\n");
231     Advisor = llvm::getDevelopmentModeAdvisor(M, MAM, GetDefaultAdvice);
232 #endif
233     break;
234   case InliningAdvisorMode::Release:
235     LLVM_DEBUG(dbgs() << "Using release-mode inliner policy.\n");
236     Advisor = llvm::getReleaseModeAdvisor(M, MAM, GetDefaultAdvice);
237     break;
238   }
239 
240   return !!Advisor;
241 }
242 
243 /// Return true if inlining of CB can block the caller from being
244 /// inlined which is proved to be more beneficial. \p IC is the
245 /// estimated inline cost associated with callsite \p CB.
246 /// \p TotalSecondaryCost will be set to the estimated cost of inlining the
247 /// caller if \p CB is suppressed for inlining.
248 static bool
249 shouldBeDeferred(Function *Caller, InlineCost IC, int &TotalSecondaryCost,
250                  function_ref<InlineCost(CallBase &CB)> GetInlineCost) {
251   // For now we only handle local or inline functions.
252   if (!Caller->hasLocalLinkage() && !Caller->hasLinkOnceODRLinkage())
253     return false;
254   // If the cost of inlining CB is non-positive, it is not going to prevent the
255   // caller from being inlined into its callers and hence we don't need to
256   // defer.
257   if (IC.getCost() <= 0)
258     return false;
259   // Try to detect the case where the current inlining candidate caller (call
260   // it B) is a static or linkonce-ODR function and is an inlining candidate
261   // elsewhere, and the current candidate callee (call it C) is large enough
262   // that inlining it into B would make B too big to inline later. In these
263   // circumstances it may be best not to inline C into B, but to inline B into
264   // its callers.
265   //
266   // This only applies to static and linkonce-ODR functions because those are
267   // expected to be available for inlining in the translation units where they
268   // are used. Thus we will always have the opportunity to make local inlining
269   // decisions. Importantly the linkonce-ODR linkage covers inline functions
270   // and templates in C++.
271   //
272   // FIXME: All of this logic should be sunk into getInlineCost. It relies on
273   // the internal implementation of the inline cost metrics rather than
274   // treating them as truly abstract units etc.
275   TotalSecondaryCost = 0;
276   // The candidate cost to be imposed upon the current function.
277   int CandidateCost = IC.getCost() - 1;
278   // If the caller has local linkage and can be inlined to all its callers, we
279   // can apply a huge negative bonus to TotalSecondaryCost.
280   bool ApplyLastCallBonus = Caller->hasLocalLinkage() && !Caller->hasOneUse();
281   // This bool tracks what happens if we DO inline C into B.
282   bool InliningPreventsSomeOuterInline = false;
283   unsigned NumCallerUsers = 0;
284   for (User *U : Caller->users()) {
285     CallBase *CS2 = dyn_cast<CallBase>(U);
286 
287     // If this isn't a call to Caller (it could be some other sort
288     // of reference) skip it.  Such references will prevent the caller
289     // from being removed.
290     if (!CS2 || CS2->getCalledFunction() != Caller) {
291       ApplyLastCallBonus = false;
292       continue;
293     }
294 
295     InlineCost IC2 = GetInlineCost(*CS2);
296     ++NumCallerCallersAnalyzed;
297     if (!IC2) {
298       ApplyLastCallBonus = false;
299       continue;
300     }
301     if (IC2.isAlways())
302       continue;
303 
304     // See if inlining of the original callsite would erase the cost delta of
305     // this callsite. We subtract off the penalty for the call instruction,
306     // which we would be deleting.
307     if (IC2.getCostDelta() <= CandidateCost) {
308       InliningPreventsSomeOuterInline = true;
309       TotalSecondaryCost += IC2.getCost();
310       NumCallerUsers++;
311     }
312   }
313 
314   if (!InliningPreventsSomeOuterInline)
315     return false;
316 
317   // If all outer calls to Caller would get inlined, the cost for the last
318   // one is set very low by getInlineCost, in anticipation that Caller will
319   // be removed entirely.  We did not account for this above unless there
320   // is only one caller of Caller.
321   if (ApplyLastCallBonus)
322     TotalSecondaryCost -= InlineConstants::LastCallToStaticBonus;
323 
324   // If InlineDeferralScale is negative, then ignore the cost of primary
325   // inlining -- IC.getCost() multiplied by the number of callers to Caller.
326   if (InlineDeferralScale < 0)
327     return TotalSecondaryCost < IC.getCost();
328 
329   int TotalCost = TotalSecondaryCost + IC.getCost() * NumCallerUsers;
330   int Allowance = IC.getCost() * InlineDeferralScale;
331   return TotalCost < Allowance;
332 }
333 
334 namespace llvm {
335 static raw_ostream &operator<<(raw_ostream &R, const ore::NV &Arg) {
336   return R << Arg.Val;
337 }
338 
339 template <class RemarkT>
340 RemarkT &operator<<(RemarkT &&R, const InlineCost &IC) {
341   using namespace ore;
342   if (IC.isAlways()) {
343     R << "(cost=always)";
344   } else if (IC.isNever()) {
345     R << "(cost=never)";
346   } else {
347     R << "(cost=" << ore::NV("Cost", IC.getCost())
348       << ", threshold=" << ore::NV("Threshold", IC.getThreshold()) << ")";
349   }
350   if (const char *Reason = IC.getReason())
351     R << ": " << ore::NV("Reason", Reason);
352   return R;
353 }
354 } // namespace llvm
355 
356 std::string llvm::inlineCostStr(const InlineCost &IC) {
357   std::string Buffer;
358   raw_string_ostream Remark(Buffer);
359   Remark << IC;
360   return Remark.str();
361 }
362 
363 void llvm::setInlineRemark(CallBase &CB, StringRef Message) {
364   if (!InlineRemarkAttribute)
365     return;
366 
367   Attribute Attr = Attribute::get(CB.getContext(), "inline-remark", Message);
368   CB.addFnAttr(Attr);
369 }
370 
371 /// Return the cost only if the inliner should attempt to inline at the given
372 /// CallSite. If we return the cost, we will emit an optimisation remark later
373 /// using that cost, so we won't do so from this function. Return std::nullopt
374 /// if inlining should not be attempted.
375 std::optional<InlineCost>
376 llvm::shouldInline(CallBase &CB,
377                    function_ref<InlineCost(CallBase &CB)> GetInlineCost,
378                    OptimizationRemarkEmitter &ORE, bool EnableDeferral) {
379   using namespace ore;
380 
381   InlineCost IC = GetInlineCost(CB);
382   Instruction *Call = &CB;
383   Function *Callee = CB.getCalledFunction();
384   Function *Caller = CB.getCaller();
385 
386   if (IC.isAlways()) {
387     LLVM_DEBUG(dbgs() << "    Inlining " << inlineCostStr(IC)
388                       << ", Call: " << CB << "\n");
389     return IC;
390   }
391 
392   if (!IC) {
393     LLVM_DEBUG(dbgs() << "    NOT Inlining " << inlineCostStr(IC)
394                       << ", Call: " << CB << "\n");
395     if (IC.isNever()) {
396       ORE.emit([&]() {
397         return OptimizationRemarkMissed(DEBUG_TYPE, "NeverInline", Call)
398                << "'" << NV("Callee", Callee) << "' not inlined into '"
399                << NV("Caller", Caller)
400                << "' because it should never be inlined " << IC;
401       });
402     } else {
403       ORE.emit([&]() {
404         return OptimizationRemarkMissed(DEBUG_TYPE, "TooCostly", Call)
405                << "'" << NV("Callee", Callee) << "' not inlined into '"
406                << NV("Caller", Caller) << "' because too costly to inline "
407                << IC;
408       });
409     }
410     setInlineRemark(CB, inlineCostStr(IC));
411     return std::nullopt;
412   }
413 
414   int TotalSecondaryCost = 0;
415   if (EnableDeferral &&
416       shouldBeDeferred(Caller, IC, TotalSecondaryCost, GetInlineCost)) {
417     LLVM_DEBUG(dbgs() << "    NOT Inlining: " << CB
418                       << " Cost = " << IC.getCost()
419                       << ", outer Cost = " << TotalSecondaryCost << '\n');
420     ORE.emit([&]() {
421       return OptimizationRemarkMissed(DEBUG_TYPE, "IncreaseCostInOtherContexts",
422                                       Call)
423              << "Not inlining. Cost of inlining '" << NV("Callee", Callee)
424              << "' increases the cost of inlining '" << NV("Caller", Caller)
425              << "' in other contexts";
426     });
427     setInlineRemark(CB, "deferred");
428     return std::nullopt;
429   }
430 
431   LLVM_DEBUG(dbgs() << "    Inlining " << inlineCostStr(IC) << ", Call: " << CB
432                     << '\n');
433   return IC;
434 }
435 
436 std::string llvm::formatCallSiteLocation(DebugLoc DLoc,
437                                          const CallSiteFormat &Format) {
438   std::string Buffer;
439   raw_string_ostream CallSiteLoc(Buffer);
440   bool First = true;
441   for (DILocation *DIL = DLoc.get(); DIL; DIL = DIL->getInlinedAt()) {
442     if (!First)
443       CallSiteLoc << " @ ";
444     // Note that negative line offset is actually possible, but we use
445     // unsigned int to match line offset representation in remarks so
446     // it's directly consumable by relay advisor.
447     uint32_t Offset =
448         DIL->getLine() - DIL->getScope()->getSubprogram()->getLine();
449     uint32_t Discriminator = DIL->getBaseDiscriminator();
450     StringRef Name = DIL->getScope()->getSubprogram()->getLinkageName();
451     if (Name.empty())
452       Name = DIL->getScope()->getSubprogram()->getName();
453     CallSiteLoc << Name.str() << ":" << llvm::utostr(Offset);
454     if (Format.outputColumn())
455       CallSiteLoc << ":" << llvm::utostr(DIL->getColumn());
456     if (Format.outputDiscriminator() && Discriminator)
457       CallSiteLoc << "." << llvm::utostr(Discriminator);
458     First = false;
459   }
460 
461   return CallSiteLoc.str();
462 }
463 
464 void llvm::addLocationToRemarks(OptimizationRemark &Remark, DebugLoc DLoc) {
465   if (!DLoc) {
466     return;
467   }
468 
469   bool First = true;
470   Remark << " at callsite ";
471   for (DILocation *DIL = DLoc.get(); DIL; DIL = DIL->getInlinedAt()) {
472     if (!First)
473       Remark << " @ ";
474     unsigned int Offset = DIL->getLine();
475     Offset -= DIL->getScope()->getSubprogram()->getLine();
476     unsigned int Discriminator = DIL->getBaseDiscriminator();
477     StringRef Name = DIL->getScope()->getSubprogram()->getLinkageName();
478     if (Name.empty())
479       Name = DIL->getScope()->getSubprogram()->getName();
480     Remark << Name << ":" << ore::NV("Line", Offset) << ":"
481            << ore::NV("Column", DIL->getColumn());
482     if (Discriminator)
483       Remark << "." << ore::NV("Disc", Discriminator);
484     First = false;
485   }
486 
487   Remark << ";";
488 }
489 
490 void llvm::emitInlinedInto(
491     OptimizationRemarkEmitter &ORE, DebugLoc DLoc, const BasicBlock *Block,
492     const Function &Callee, const Function &Caller, bool AlwaysInline,
493     function_ref<void(OptimizationRemark &)> ExtraContext,
494     const char *PassName) {
495   ORE.emit([&]() {
496     StringRef RemarkName = AlwaysInline ? "AlwaysInline" : "Inlined";
497     OptimizationRemark Remark(PassName ? PassName : DEBUG_TYPE, RemarkName,
498                               DLoc, Block);
499     Remark << "'" << ore::NV("Callee", &Callee) << "' inlined into '"
500            << ore::NV("Caller", &Caller) << "'";
501     if (ExtraContext)
502       ExtraContext(Remark);
503     addLocationToRemarks(Remark, DLoc);
504     return Remark;
505   });
506 }
507 
508 void llvm::emitInlinedIntoBasedOnCost(
509     OptimizationRemarkEmitter &ORE, DebugLoc DLoc, const BasicBlock *Block,
510     const Function &Callee, const Function &Caller, const InlineCost &IC,
511     bool ForProfileContext, const char *PassName) {
512   llvm::emitInlinedInto(
513       ORE, DLoc, Block, Callee, Caller, IC.isAlways(),
514       [&](OptimizationRemark &Remark) {
515         if (ForProfileContext)
516           Remark << " to match profiling context";
517         Remark << " with " << IC;
518       },
519       PassName);
520 }
521 
522 InlineAdvisor::InlineAdvisor(Module &M, FunctionAnalysisManager &FAM,
523                              std::optional<InlineContext> IC)
524     : M(M), FAM(FAM), IC(IC),
525       AnnotatedInlinePassName((IC && AnnotateInlinePhase)
526                                   ? llvm::AnnotateInlinePassName(*IC)
527                                   : DEBUG_TYPE) {
528   if (InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No) {
529     ImportedFunctionsStats =
530         std::make_unique<ImportedFunctionsInliningStatistics>();
531     ImportedFunctionsStats->setModuleInfo(M);
532   }
533 }
534 
535 InlineAdvisor::~InlineAdvisor() {
536   if (ImportedFunctionsStats) {
537     assert(InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No);
538     ImportedFunctionsStats->dump(InlinerFunctionImportStats ==
539                                  InlinerFunctionImportStatsOpts::Verbose);
540   }
541 }
542 
543 std::unique_ptr<InlineAdvice> InlineAdvisor::getMandatoryAdvice(CallBase &CB,
544                                                                 bool Advice) {
545   return std::make_unique<MandatoryInlineAdvice>(this, CB, getCallerORE(CB),
546                                                  Advice);
547 }
548 
549 static inline const char *getLTOPhase(ThinOrFullLTOPhase LTOPhase) {
550   switch (LTOPhase) {
551   case (ThinOrFullLTOPhase::None):
552     return "main";
553   case (ThinOrFullLTOPhase::ThinLTOPreLink):
554   case (ThinOrFullLTOPhase::FullLTOPreLink):
555     return "prelink";
556   case (ThinOrFullLTOPhase::ThinLTOPostLink):
557   case (ThinOrFullLTOPhase::FullLTOPostLink):
558     return "postlink";
559   }
560   llvm_unreachable("unreachable");
561 }
562 
563 static inline const char *getInlineAdvisorContext(InlinePass IP) {
564   switch (IP) {
565   case (InlinePass::AlwaysInliner):
566     return "always-inline";
567   case (InlinePass::CGSCCInliner):
568     return "cgscc-inline";
569   case (InlinePass::EarlyInliner):
570     return "early-inline";
571   case (InlinePass::MLInliner):
572     return "ml-inline";
573   case (InlinePass::ModuleInliner):
574     return "module-inline";
575   case (InlinePass::ReplayCGSCCInliner):
576     return "replay-cgscc-inline";
577   case (InlinePass::ReplaySampleProfileInliner):
578     return "replay-sample-profile-inline";
579   case (InlinePass::SampleProfileInliner):
580     return "sample-profile-inline";
581   }
582 
583   llvm_unreachable("unreachable");
584 }
585 
586 std::string llvm::AnnotateInlinePassName(InlineContext IC) {
587   return std::string(getLTOPhase(IC.LTOPhase)) + "-" +
588          std::string(getInlineAdvisorContext(IC.Pass));
589 }
590 
591 InlineAdvisor::MandatoryInliningKind
592 InlineAdvisor::getMandatoryKind(CallBase &CB, FunctionAnalysisManager &FAM,
593                                 OptimizationRemarkEmitter &ORE) {
594   auto &Callee = *CB.getCalledFunction();
595 
596   auto GetTLI = [&](Function &F) -> const TargetLibraryInfo & {
597     return FAM.getResult<TargetLibraryAnalysis>(F);
598   };
599 
600   auto &TIR = FAM.getResult<TargetIRAnalysis>(Callee);
601 
602   auto TrivialDecision =
603       llvm::getAttributeBasedInliningDecision(CB, &Callee, TIR, GetTLI);
604 
605   if (TrivialDecision) {
606     if (TrivialDecision->isSuccess())
607       return MandatoryInliningKind::Always;
608     else
609       return MandatoryInliningKind::Never;
610   }
611   return MandatoryInliningKind::NotMandatory;
612 }
613 
614 std::unique_ptr<InlineAdvice> InlineAdvisor::getAdvice(CallBase &CB,
615                                                        bool MandatoryOnly) {
616   if (!MandatoryOnly)
617     return getAdviceImpl(CB);
618   bool Advice = CB.getCaller() != CB.getCalledFunction() &&
619                 MandatoryInliningKind::Always ==
620                     getMandatoryKind(CB, FAM, getCallerORE(CB));
621   return getMandatoryAdvice(CB, Advice);
622 }
623 
624 OptimizationRemarkEmitter &InlineAdvisor::getCallerORE(CallBase &CB) {
625   return FAM.getResult<OptimizationRemarkEmitterAnalysis>(*CB.getCaller());
626 }
627 
628 PreservedAnalyses
629 InlineAdvisorAnalysisPrinterPass::run(Module &M, ModuleAnalysisManager &MAM) {
630   const auto *IA = MAM.getCachedResult<InlineAdvisorAnalysis>(M);
631   if (!IA)
632     OS << "No Inline Advisor\n";
633   else
634     IA->getAdvisor()->print(OS);
635   return PreservedAnalyses::all();
636 }
637 
638 PreservedAnalyses InlineAdvisorAnalysisPrinterPass::run(
639     LazyCallGraph::SCC &InitialC, CGSCCAnalysisManager &AM, LazyCallGraph &CG,
640     CGSCCUpdateResult &UR) {
641   const auto &MAMProxy =
642       AM.getResult<ModuleAnalysisManagerCGSCCProxy>(InitialC, CG);
643 
644   if (InitialC.size() == 0) {
645     OS << "SCC is empty!\n";
646     return PreservedAnalyses::all();
647   }
648   Module &M = *InitialC.begin()->getFunction().getParent();
649   const auto *IA = MAMProxy.getCachedResult<InlineAdvisorAnalysis>(M);
650   if (!IA)
651     OS << "No Inline Advisor\n";
652   else
653     IA->getAdvisor()->print(OS);
654   return PreservedAnalyses::all();
655 }
656