xref: /llvm-project/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp (revision 5f7aff9a0a8b651348b024bd240fdb705d907f12)
1 //===- ModuleSummaryAnalysis.cpp - Module summary index builder -----------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This pass builds a ModuleSummaryIndex object for the module, to be written
11 // to bitcode or LLVM assembly.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/Analysis/ModuleSummaryAnalysis.h"
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/DenseSet.h"
18 #include "llvm/ADT/MapVector.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/SetVector.h"
21 #include "llvm/ADT/SmallPtrSet.h"
22 #include "llvm/ADT/SmallVector.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/Analysis/BlockFrequencyInfo.h"
25 #include "llvm/Analysis/BranchProbabilityInfo.h"
26 #include "llvm/Analysis/IndirectCallPromotionAnalysis.h"
27 #include "llvm/Analysis/LoopInfo.h"
28 #include "llvm/Analysis/ProfileSummaryInfo.h"
29 #include "llvm/Analysis/TypeMetadataUtils.h"
30 #include "llvm/IR/Attributes.h"
31 #include "llvm/IR/BasicBlock.h"
32 #include "llvm/IR/CallSite.h"
33 #include "llvm/IR/Constant.h"
34 #include "llvm/IR/Constants.h"
35 #include "llvm/IR/Dominators.h"
36 #include "llvm/IR/Function.h"
37 #include "llvm/IR/GlobalAlias.h"
38 #include "llvm/IR/GlobalValue.h"
39 #include "llvm/IR/GlobalVariable.h"
40 #include "llvm/IR/Instructions.h"
41 #include "llvm/IR/IntrinsicInst.h"
42 #include "llvm/IR/Intrinsics.h"
43 #include "llvm/IR/Metadata.h"
44 #include "llvm/IR/Module.h"
45 #include "llvm/IR/ModuleSummaryIndex.h"
46 #include "llvm/IR/Use.h"
47 #include "llvm/IR/User.h"
48 #include "llvm/Object/ModuleSymbolTable.h"
49 #include "llvm/Object/SymbolicFile.h"
50 #include "llvm/Pass.h"
51 #include "llvm/Support/Casting.h"
52 #include <algorithm>
53 #include <cassert>
54 #include <cstdint>
55 #include <vector>
56 
57 using namespace llvm;
58 
59 #define DEBUG_TYPE "module-summary-analysis"
60 
61 // Walk through the operands of a given User via worklist iteration and populate
62 // the set of GlobalValue references encountered. Invoked either on an
63 // Instruction or a GlobalVariable (which walks its initializer).
64 static void findRefEdges(ModuleSummaryIndex &Index, const User *CurUser,
65                          SetVector<ValueInfo> &RefEdges,
66                          SmallPtrSet<const User *, 8> &Visited) {
67   SmallVector<const User *, 32> Worklist;
68   Worklist.push_back(CurUser);
69 
70   while (!Worklist.empty()) {
71     const User *U = Worklist.pop_back_val();
72 
73     if (!Visited.insert(U).second)
74       continue;
75 
76     ImmutableCallSite CS(U);
77 
78     for (const auto &OI : U->operands()) {
79       const User *Operand = dyn_cast<User>(OI);
80       if (!Operand)
81         continue;
82       if (isa<BlockAddress>(Operand))
83         continue;
84       if (auto *GV = dyn_cast<GlobalValue>(Operand)) {
85         // We have a reference to a global value. This should be added to
86         // the reference set unless it is a callee. Callees are handled
87         // specially by WriteFunction and are added to a separate list.
88         if (!(CS && CS.isCallee(&OI)))
89           RefEdges.insert(Index.getOrInsertValueInfo(GV));
90         continue;
91       }
92       Worklist.push_back(Operand);
93     }
94   }
95 }
96 
97 static CalleeInfo::HotnessType getHotness(uint64_t ProfileCount,
98                                           ProfileSummaryInfo *PSI) {
99   if (!PSI)
100     return CalleeInfo::HotnessType::Unknown;
101   if (PSI->isHotCount(ProfileCount))
102     return CalleeInfo::HotnessType::Hot;
103   if (PSI->isColdCount(ProfileCount))
104     return CalleeInfo::HotnessType::Cold;
105   return CalleeInfo::HotnessType::None;
106 }
107 
108 static bool isNonRenamableLocal(const GlobalValue &GV) {
109   return GV.hasSection() && GV.hasLocalLinkage();
110 }
111 
112 /// Determine whether this call has all constant integer arguments (excluding
113 /// "this") and summarize it to VCalls or ConstVCalls as appropriate.
114 static void addVCallToSet(DevirtCallSite Call, GlobalValue::GUID Guid,
115                           SetVector<FunctionSummary::VFuncId> &VCalls,
116                           SetVector<FunctionSummary::ConstVCall> &ConstVCalls) {
117   std::vector<uint64_t> Args;
118   // Start from the second argument to skip the "this" pointer.
119   for (auto &Arg : make_range(Call.CS.arg_begin() + 1, Call.CS.arg_end())) {
120     auto *CI = dyn_cast<ConstantInt>(Arg);
121     if (!CI || CI->getBitWidth() > 64) {
122       VCalls.insert({Guid, Call.Offset});
123       return;
124     }
125     Args.push_back(CI->getZExtValue());
126   }
127   ConstVCalls.insert({{Guid, Call.Offset}, std::move(Args)});
128 }
129 
130 /// If this intrinsic call requires that we add information to the function
131 /// summary, do so via the non-constant reference arguments.
132 static void addIntrinsicToSummary(
133     const CallInst *CI, SetVector<GlobalValue::GUID> &TypeTests,
134     SetVector<FunctionSummary::VFuncId> &TypeTestAssumeVCalls,
135     SetVector<FunctionSummary::VFuncId> &TypeCheckedLoadVCalls,
136     SetVector<FunctionSummary::ConstVCall> &TypeTestAssumeConstVCalls,
137     SetVector<FunctionSummary::ConstVCall> &TypeCheckedLoadConstVCalls) {
138   switch (CI->getCalledFunction()->getIntrinsicID()) {
139   case Intrinsic::type_test: {
140     auto *TypeMDVal = cast<MetadataAsValue>(CI->getArgOperand(1));
141     auto *TypeId = dyn_cast<MDString>(TypeMDVal->getMetadata());
142     if (!TypeId)
143       break;
144     GlobalValue::GUID Guid = GlobalValue::getGUID(TypeId->getString());
145 
146     // Produce a summary from type.test intrinsics. We only summarize type.test
147     // intrinsics that are used other than by an llvm.assume intrinsic.
148     // Intrinsics that are assumed are relevant only to the devirtualization
149     // pass, not the type test lowering pass.
150     bool HasNonAssumeUses = llvm::any_of(CI->uses(), [](const Use &CIU) {
151       auto *AssumeCI = dyn_cast<CallInst>(CIU.getUser());
152       if (!AssumeCI)
153         return true;
154       Function *F = AssumeCI->getCalledFunction();
155       return !F || F->getIntrinsicID() != Intrinsic::assume;
156     });
157     if (HasNonAssumeUses)
158       TypeTests.insert(Guid);
159 
160     SmallVector<DevirtCallSite, 4> DevirtCalls;
161     SmallVector<CallInst *, 4> Assumes;
162     findDevirtualizableCallsForTypeTest(DevirtCalls, Assumes, CI);
163     for (auto &Call : DevirtCalls)
164       addVCallToSet(Call, Guid, TypeTestAssumeVCalls,
165                     TypeTestAssumeConstVCalls);
166 
167     break;
168   }
169 
170   case Intrinsic::type_checked_load: {
171     auto *TypeMDVal = cast<MetadataAsValue>(CI->getArgOperand(2));
172     auto *TypeId = dyn_cast<MDString>(TypeMDVal->getMetadata());
173     if (!TypeId)
174       break;
175     GlobalValue::GUID Guid = GlobalValue::getGUID(TypeId->getString());
176 
177     SmallVector<DevirtCallSite, 4> DevirtCalls;
178     SmallVector<Instruction *, 4> LoadedPtrs;
179     SmallVector<Instruction *, 4> Preds;
180     bool HasNonCallUses = false;
181     findDevirtualizableCallsForTypeCheckedLoad(DevirtCalls, LoadedPtrs, Preds,
182                                                HasNonCallUses, CI);
183     // Any non-call uses of the result of llvm.type.checked.load will
184     // prevent us from optimizing away the llvm.type.test.
185     if (HasNonCallUses)
186       TypeTests.insert(Guid);
187     for (auto &Call : DevirtCalls)
188       addVCallToSet(Call, Guid, TypeCheckedLoadVCalls,
189                     TypeCheckedLoadConstVCalls);
190 
191     break;
192   }
193   default:
194     break;
195   }
196 }
197 
198 static void
199 computeFunctionSummary(ModuleSummaryIndex &Index, const Module &M,
200                        const Function &F, BlockFrequencyInfo *BFI,
201                        ProfileSummaryInfo *PSI, bool HasLocalsInUsedOrAsm,
202                        DenseSet<GlobalValue::GUID> &CantBePromoted) {
203   // Summary not currently supported for anonymous functions, they should
204   // have been named.
205   assert(F.hasName());
206 
207   unsigned NumInsts = 0;
208   // Map from callee ValueId to profile count. Used to accumulate profile
209   // counts for all static calls to a given callee.
210   MapVector<ValueInfo, CalleeInfo> CallGraphEdges;
211   SetVector<ValueInfo> RefEdges;
212   SetVector<GlobalValue::GUID> TypeTests;
213   SetVector<FunctionSummary::VFuncId> TypeTestAssumeVCalls,
214       TypeCheckedLoadVCalls;
215   SetVector<FunctionSummary::ConstVCall> TypeTestAssumeConstVCalls,
216       TypeCheckedLoadConstVCalls;
217   ICallPromotionAnalysis ICallAnalysis;
218   SmallPtrSet<const User *, 8> Visited;
219 
220   // Add personality function, prefix data and prologue data to function's ref
221   // list.
222   findRefEdges(Index, &F, RefEdges, Visited);
223 
224   bool HasInlineAsmMaybeReferencingInternal = false;
225   for (const BasicBlock &BB : F)
226     for (const Instruction &I : BB) {
227       if (isa<DbgInfoIntrinsic>(I))
228         continue;
229       ++NumInsts;
230       findRefEdges(Index, &I, RefEdges, Visited);
231       auto CS = ImmutableCallSite(&I);
232       if (!CS)
233         continue;
234 
235       const auto *CI = dyn_cast<CallInst>(&I);
236       // Since we don't know exactly which local values are referenced in inline
237       // assembly, conservatively mark the function as possibly referencing
238       // a local value from inline assembly to ensure we don't export a
239       // reference (which would require renaming and promotion of the
240       // referenced value).
241       if (HasLocalsInUsedOrAsm && CI && CI->isInlineAsm())
242         HasInlineAsmMaybeReferencingInternal = true;
243 
244       auto *CalledValue = CS.getCalledValue();
245       auto *CalledFunction = CS.getCalledFunction();
246       if (CalledValue && !CalledFunction) {
247         CalledValue = CalledValue->stripPointerCastsNoFollowAliases();
248         // Stripping pointer casts can reveal a called function.
249         CalledFunction = dyn_cast<Function>(CalledValue);
250       }
251       // Check if this is an alias to a function. If so, get the
252       // called aliasee for the checks below.
253       if (auto *GA = dyn_cast<GlobalAlias>(CalledValue)) {
254         assert(!CalledFunction && "Expected null called function in callsite for alias");
255         CalledFunction = dyn_cast<Function>(GA->getBaseObject());
256       }
257       // Check if this is a direct call to a known function or a known
258       // intrinsic, or an indirect call with profile data.
259       if (CalledFunction) {
260         if (CI && CalledFunction->isIntrinsic()) {
261           addIntrinsicToSummary(
262               CI, TypeTests, TypeTestAssumeVCalls, TypeCheckedLoadVCalls,
263               TypeTestAssumeConstVCalls, TypeCheckedLoadConstVCalls);
264           continue;
265         }
266         // We should have named any anonymous globals
267         assert(CalledFunction->hasName());
268         auto ScaledCount = PSI->getProfileCount(&I, BFI);
269         auto Hotness = ScaledCount ? getHotness(ScaledCount.getValue(), PSI)
270                                    : CalleeInfo::HotnessType::Unknown;
271 
272         // Use the original CalledValue, in case it was an alias. We want
273         // to record the call edge to the alias in that case. Eventually
274         // an alias summary will be created to associate the alias and
275         // aliasee.
276         auto &ValueInfo = CallGraphEdges[Index.getOrInsertValueInfo(
277             cast<GlobalValue>(CalledValue))];
278         ValueInfo.updateHotness(Hotness);
279         // Add the relative block frequency to CalleeInfo if there is no profile
280         // information.
281         if (BFI != nullptr && Hotness == CalleeInfo::HotnessType::Unknown) {
282           auto BBFreq = BFI->getBlockFreq(CI->getParent()).getFrequency();
283           // FIXME: This might need some scaling to prevent BBFreq values from
284           // being rounded down to 0.
285           auto EntryFreq = BFI->getEntryFreq();
286           // Block frequencies can be directly set for a block and so we need to
287           // handle the case of entry frequency being 0.
288           if (EntryFreq)
289             BBFreq /= EntryFreq;
290           else
291             BBFreq = 0;
292           ValueInfo.updateRelBlockFreq(BBFreq);
293         }
294       } else {
295         // Skip inline assembly calls.
296         if (CI && CI->isInlineAsm())
297           continue;
298         // Skip direct calls.
299         if (!CalledValue || isa<Constant>(CalledValue))
300           continue;
301 
302         uint32_t NumVals, NumCandidates;
303         uint64_t TotalCount;
304         auto CandidateProfileData =
305             ICallAnalysis.getPromotionCandidatesForInstruction(
306                 &I, NumVals, TotalCount, NumCandidates);
307         for (auto &Candidate : CandidateProfileData)
308           CallGraphEdges[Index.getOrInsertValueInfo(Candidate.Value)]
309               .updateHotness(getHotness(Candidate.Count, PSI));
310       }
311     }
312 
313   // Explicit add hot edges to enforce importing for designated GUIDs for
314   // sample PGO, to enable the same inlines as the profiled optimized binary.
315   for (auto &I : F.getImportGUIDs())
316     CallGraphEdges[Index.getOrInsertValueInfo(I)].updateHotness(
317         CalleeInfo::HotnessType::Critical);
318 
319   bool NonRenamableLocal = isNonRenamableLocal(F);
320   bool NotEligibleForImport =
321       NonRenamableLocal || HasInlineAsmMaybeReferencingInternal ||
322       // Inliner doesn't handle variadic functions.
323       // FIXME: refactor this to use the same code that inliner is using.
324       F.isVarArg() ||
325       // Don't try to import functions with noinline attribute.
326       F.getAttributes().hasFnAttribute(Attribute::NoInline);
327   GlobalValueSummary::GVFlags Flags(F.getLinkage(), NotEligibleForImport,
328                                     /* Live = */ false, F.isDSOLocal());
329   FunctionSummary::FFlags FunFlags{
330       F.hasFnAttribute(Attribute::ReadNone),
331       F.hasFnAttribute(Attribute::ReadOnly),
332       F.hasFnAttribute(Attribute::NoRecurse),
333       F.returnDoesNotAlias(),
334   };
335   auto FuncSummary = llvm::make_unique<FunctionSummary>(
336       Flags, NumInsts, FunFlags, RefEdges.takeVector(),
337       CallGraphEdges.takeVector(), TypeTests.takeVector(),
338       TypeTestAssumeVCalls.takeVector(), TypeCheckedLoadVCalls.takeVector(),
339       TypeTestAssumeConstVCalls.takeVector(),
340       TypeCheckedLoadConstVCalls.takeVector());
341   if (NonRenamableLocal)
342     CantBePromoted.insert(F.getGUID());
343   Index.addGlobalValueSummary(F.getName(), std::move(FuncSummary));
344 }
345 
346 static void
347 computeVariableSummary(ModuleSummaryIndex &Index, const GlobalVariable &V,
348                        DenseSet<GlobalValue::GUID> &CantBePromoted) {
349   SetVector<ValueInfo> RefEdges;
350   SmallPtrSet<const User *, 8> Visited;
351   findRefEdges(Index, &V, RefEdges, Visited);
352   bool NonRenamableLocal = isNonRenamableLocal(V);
353   GlobalValueSummary::GVFlags Flags(V.getLinkage(), NonRenamableLocal,
354                                     /* Live = */ false, V.isDSOLocal());
355   auto GVarSummary =
356       llvm::make_unique<GlobalVarSummary>(Flags, RefEdges.takeVector());
357   if (NonRenamableLocal)
358     CantBePromoted.insert(V.getGUID());
359   Index.addGlobalValueSummary(V.getName(), std::move(GVarSummary));
360 }
361 
362 static void
363 computeAliasSummary(ModuleSummaryIndex &Index, const GlobalAlias &A,
364                     DenseSet<GlobalValue::GUID> &CantBePromoted) {
365   bool NonRenamableLocal = isNonRenamableLocal(A);
366   GlobalValueSummary::GVFlags Flags(A.getLinkage(), NonRenamableLocal,
367                                     /* Live = */ false, A.isDSOLocal());
368   auto AS = llvm::make_unique<AliasSummary>(Flags);
369   auto *Aliasee = A.getBaseObject();
370   auto *AliaseeSummary = Index.getGlobalValueSummary(*Aliasee);
371   assert(AliaseeSummary && "Alias expects aliasee summary to be parsed");
372   AS->setAliasee(AliaseeSummary);
373   if (NonRenamableLocal)
374     CantBePromoted.insert(A.getGUID());
375   Index.addGlobalValueSummary(A.getName(), std::move(AS));
376 }
377 
378 // Set LiveRoot flag on entries matching the given value name.
379 static void setLiveRoot(ModuleSummaryIndex &Index, StringRef Name) {
380   if (ValueInfo VI = Index.getValueInfo(GlobalValue::getGUID(Name)))
381     for (auto &Summary : VI.getSummaryList())
382       Summary->setLive(true);
383 }
384 
385 ModuleSummaryIndex llvm::buildModuleSummaryIndex(
386     const Module &M,
387     std::function<BlockFrequencyInfo *(const Function &F)> GetBFICallback,
388     ProfileSummaryInfo *PSI) {
389   assert(PSI);
390   ModuleSummaryIndex Index(/*IsPerformingAnalysis=*/true);
391 
392   // Identify the local values in the llvm.used and llvm.compiler.used sets,
393   // which should not be exported as they would then require renaming and
394   // promotion, but we may have opaque uses e.g. in inline asm. We collect them
395   // here because we use this information to mark functions containing inline
396   // assembly calls as not importable.
397   SmallPtrSet<GlobalValue *, 8> LocalsUsed;
398   SmallPtrSet<GlobalValue *, 8> Used;
399   // First collect those in the llvm.used set.
400   collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
401   // Next collect those in the llvm.compiler.used set.
402   collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ true);
403   DenseSet<GlobalValue::GUID> CantBePromoted;
404   for (auto *V : Used) {
405     if (V->hasLocalLinkage()) {
406       LocalsUsed.insert(V);
407       CantBePromoted.insert(V->getGUID());
408     }
409   }
410 
411   bool HasLocalInlineAsmSymbol = false;
412   if (!M.getModuleInlineAsm().empty()) {
413     // Collect the local values defined by module level asm, and set up
414     // summaries for these symbols so that they can be marked as NoRename,
415     // to prevent export of any use of them in regular IR that would require
416     // renaming within the module level asm. Note we don't need to create a
417     // summary for weak or global defs, as they don't need to be flagged as
418     // NoRename, and defs in module level asm can't be imported anyway.
419     // Also, any values used but not defined within module level asm should
420     // be listed on the llvm.used or llvm.compiler.used global and marked as
421     // referenced from there.
422     ModuleSymbolTable::CollectAsmSymbols(
423         M, [&](StringRef Name, object::BasicSymbolRef::Flags Flags) {
424           // Symbols not marked as Weak or Global are local definitions.
425           if (Flags & (object::BasicSymbolRef::SF_Weak |
426                        object::BasicSymbolRef::SF_Global))
427             return;
428           HasLocalInlineAsmSymbol = true;
429           GlobalValue *GV = M.getNamedValue(Name);
430           if (!GV)
431             return;
432           assert(GV->isDeclaration() && "Def in module asm already has definition");
433           GlobalValueSummary::GVFlags GVFlags(GlobalValue::InternalLinkage,
434                                               /* NotEligibleToImport = */ true,
435                                               /* Live = */ true,
436                                               /* Local */ GV->isDSOLocal());
437           CantBePromoted.insert(GlobalValue::getGUID(Name));
438           // Create the appropriate summary type.
439           if (Function *F = dyn_cast<Function>(GV)) {
440             std::unique_ptr<FunctionSummary> Summary =
441                 llvm::make_unique<FunctionSummary>(
442                     GVFlags, 0,
443                     FunctionSummary::FFlags{
444                         F->hasFnAttribute(Attribute::ReadNone),
445                         F->hasFnAttribute(Attribute::ReadOnly),
446                         F->hasFnAttribute(Attribute::NoRecurse),
447                         F->returnDoesNotAlias()},
448                     ArrayRef<ValueInfo>{}, ArrayRef<FunctionSummary::EdgeTy>{},
449                     ArrayRef<GlobalValue::GUID>{},
450                     ArrayRef<FunctionSummary::VFuncId>{},
451                     ArrayRef<FunctionSummary::VFuncId>{},
452                     ArrayRef<FunctionSummary::ConstVCall>{},
453                     ArrayRef<FunctionSummary::ConstVCall>{});
454             Index.addGlobalValueSummary(Name, std::move(Summary));
455           } else {
456             std::unique_ptr<GlobalVarSummary> Summary =
457                 llvm::make_unique<GlobalVarSummary>(GVFlags,
458                                                     ArrayRef<ValueInfo>{});
459             Index.addGlobalValueSummary(Name, std::move(Summary));
460           }
461         });
462   }
463 
464   // Compute summaries for all functions defined in module, and save in the
465   // index.
466   for (auto &F : M) {
467     if (F.isDeclaration())
468       continue;
469 
470     BlockFrequencyInfo *BFI = nullptr;
471     std::unique_ptr<BlockFrequencyInfo> BFIPtr;
472     if (GetBFICallback)
473       BFI = GetBFICallback(F);
474     else if (F.hasProfileData()) {
475       LoopInfo LI{DominatorTree(const_cast<Function &>(F))};
476       BranchProbabilityInfo BPI{F, LI};
477       BFIPtr = llvm::make_unique<BlockFrequencyInfo>(F, BPI, LI);
478       BFI = BFIPtr.get();
479     }
480 
481     computeFunctionSummary(Index, M, F, BFI, PSI,
482                            !LocalsUsed.empty() || HasLocalInlineAsmSymbol,
483                            CantBePromoted);
484   }
485 
486   // Compute summaries for all variables defined in module, and save in the
487   // index.
488   for (const GlobalVariable &G : M.globals()) {
489     if (G.isDeclaration())
490       continue;
491     computeVariableSummary(Index, G, CantBePromoted);
492   }
493 
494   // Compute summaries for all aliases defined in module, and save in the
495   // index.
496   for (const GlobalAlias &A : M.aliases())
497     computeAliasSummary(Index, A, CantBePromoted);
498 
499   for (auto *V : LocalsUsed) {
500     auto *Summary = Index.getGlobalValueSummary(*V);
501     assert(Summary && "Missing summary for global value");
502     Summary->setNotEligibleToImport();
503   }
504 
505   // The linker doesn't know about these LLVM produced values, so we need
506   // to flag them as live in the index to ensure index-based dead value
507   // analysis treats them as live roots of the analysis.
508   setLiveRoot(Index, "llvm.used");
509   setLiveRoot(Index, "llvm.compiler.used");
510   setLiveRoot(Index, "llvm.global_ctors");
511   setLiveRoot(Index, "llvm.global_dtors");
512   setLiveRoot(Index, "llvm.global.annotations");
513 
514   bool IsThinLTO = true;
515   if (auto *MD =
516           mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("ThinLTO")))
517     IsThinLTO = MD->getZExtValue();
518 
519   for (auto &GlobalList : Index) {
520     // Ignore entries for references that are undefined in the current module.
521     if (GlobalList.second.SummaryList.empty())
522       continue;
523 
524     assert(GlobalList.second.SummaryList.size() == 1 &&
525            "Expected module's index to have one summary per GUID");
526     auto &Summary = GlobalList.second.SummaryList[0];
527     if (!IsThinLTO) {
528       Summary->setNotEligibleToImport();
529       continue;
530     }
531 
532     bool AllRefsCanBeExternallyReferenced =
533         llvm::all_of(Summary->refs(), [&](const ValueInfo &VI) {
534           return !CantBePromoted.count(VI.getGUID());
535         });
536     if (!AllRefsCanBeExternallyReferenced) {
537       Summary->setNotEligibleToImport();
538       continue;
539     }
540 
541     if (auto *FuncSummary = dyn_cast<FunctionSummary>(Summary.get())) {
542       bool AllCallsCanBeExternallyReferenced = llvm::all_of(
543           FuncSummary->calls(), [&](const FunctionSummary::EdgeTy &Edge) {
544             return !CantBePromoted.count(Edge.first.getGUID());
545           });
546       if (!AllCallsCanBeExternallyReferenced)
547         Summary->setNotEligibleToImport();
548     }
549   }
550 
551   return Index;
552 }
553 
554 AnalysisKey ModuleSummaryIndexAnalysis::Key;
555 
556 ModuleSummaryIndex
557 ModuleSummaryIndexAnalysis::run(Module &M, ModuleAnalysisManager &AM) {
558   ProfileSummaryInfo &PSI = AM.getResult<ProfileSummaryAnalysis>(M);
559   auto &FAM = AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
560   return buildModuleSummaryIndex(
561       M,
562       [&FAM](const Function &F) {
563         return &FAM.getResult<BlockFrequencyAnalysis>(
564             *const_cast<Function *>(&F));
565       },
566       &PSI);
567 }
568 
569 char ModuleSummaryIndexWrapperPass::ID = 0;
570 
571 INITIALIZE_PASS_BEGIN(ModuleSummaryIndexWrapperPass, "module-summary-analysis",
572                       "Module Summary Analysis", false, true)
573 INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfoWrapperPass)
574 INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
575 INITIALIZE_PASS_END(ModuleSummaryIndexWrapperPass, "module-summary-analysis",
576                     "Module Summary Analysis", false, true)
577 
578 ModulePass *llvm::createModuleSummaryIndexWrapperPass() {
579   return new ModuleSummaryIndexWrapperPass();
580 }
581 
582 ModuleSummaryIndexWrapperPass::ModuleSummaryIndexWrapperPass()
583     : ModulePass(ID) {
584   initializeModuleSummaryIndexWrapperPassPass(*PassRegistry::getPassRegistry());
585 }
586 
587 bool ModuleSummaryIndexWrapperPass::runOnModule(Module &M) {
588   auto &PSI = *getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
589   Index = buildModuleSummaryIndex(
590       M,
591       [this](const Function &F) {
592         return &(this->getAnalysis<BlockFrequencyInfoWrapperPass>(
593                          *const_cast<Function *>(&F))
594                      .getBFI());
595       },
596       &PSI);
597   return false;
598 }
599 
600 bool ModuleSummaryIndexWrapperPass::doFinalization(Module &M) {
601   Index.reset();
602   return false;
603 }
604 
605 void ModuleSummaryIndexWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
606   AU.setPreservesAll();
607   AU.addRequired<BlockFrequencyInfoWrapperPass>();
608   AU.addRequired<ProfileSummaryInfoWrapperPass>();
609 }
610