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Teresa Johnson2d5487c2016-04-11 13:58:45 +00001//===- 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"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000016#include "llvm/ADT/ArrayRef.h"
17#include "llvm/ADT/DenseSet.h"
Peter Collingbourne0c30f082016-12-20 21:12:28 +000018#include "llvm/ADT/MapVector.h"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000019#include "llvm/ADT/STLExtras.h"
Peter Collingbourne0c30f082016-12-20 21:12:28 +000020#include "llvm/ADT/SetVector.h"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000021#include "llvm/ADT/SmallPtrSet.h"
22#include "llvm/ADT/SmallVector.h"
23#include "llvm/ADT/StringRef.h"
Teresa Johnson2d5487c2016-04-11 13:58:45 +000024#include "llvm/Analysis/BlockFrequencyInfo.h"
Teresa Johnson2d5487c2016-04-11 13:58:45 +000025#include "llvm/Analysis/BranchProbabilityInfo.h"
Teresa Johnsoncd21a642016-07-17 14:47:01 +000026#include "llvm/Analysis/IndirectCallPromotionAnalysis.h"
Teresa Johnson2d5487c2016-04-11 13:58:45 +000027#include "llvm/Analysis/LoopInfo.h"
Piotr Padlewskid9830eb2016-09-26 20:37:32 +000028#include "llvm/Analysis/ProfileSummaryInfo.h"
Peter Collingbourne1b4137a72016-12-21 23:03:45 +000029#include "llvm/Analysis/TypeMetadataUtils.h"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000030#include "llvm/IR/Attributes.h"
31#include "llvm/IR/BasicBlock.h"
Teresa Johnson2d5487c2016-04-11 13:58:45 +000032#include "llvm/IR/CallSite.h"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000033#include "llvm/IR/Constant.h"
34#include "llvm/IR/Constants.h"
Teresa Johnson2d5487c2016-04-11 13:58:45 +000035#include "llvm/IR/Dominators.h"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000036#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"
Teresa Johnson2d5487c2016-04-11 13:58:45 +000041#include "llvm/IR/IntrinsicInst.h"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000042#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"
Peter Collingbourne61781ac2017-03-31 00:08:24 +000048#include "llvm/Object/ModuleSymbolTable.h"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000049#include "llvm/Object/SymbolicFile.h"
Teresa Johnson2d5487c2016-04-11 13:58:45 +000050#include "llvm/Pass.h"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000051#include "llvm/Support/Casting.h"
Teresa Johnsondb83ace2018-03-31 00:18:08 +000052#include "llvm/Support/CommandLine.h"
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +000053#include <algorithm>
54#include <cassert>
55#include <cstdint>
56#include <vector>
57
Teresa Johnson2d5487c2016-04-11 13:58:45 +000058using namespace llvm;
59
60#define DEBUG_TYPE "module-summary-analysis"
61
Teresa Johnsondb83ace2018-03-31 00:18:08 +000062// Option to force edges cold which will block importing when the
63// -import-cold-multiplier is set to 0. Useful for debugging.
64FunctionSummary::ForceSummaryHotnessType ForceSummaryEdgesCold =
65 FunctionSummary::FSHT_None;
66cl::opt<FunctionSummary::ForceSummaryHotnessType, true> FSEC(
67 "force-summary-edges-cold", cl::Hidden, cl::location(ForceSummaryEdgesCold),
68 cl::desc("Force all edges in the function summary to cold"),
69 cl::values(clEnumValN(FunctionSummary::FSHT_None, "none", "None."),
70 clEnumValN(FunctionSummary::FSHT_AllNonCritical,
71 "all-non-critical", "All non-critical edges."),
72 clEnumValN(FunctionSummary::FSHT_All, "all", "All edges.")));
73
Teresa Johnson2d5487c2016-04-11 13:58:45 +000074// Walk through the operands of a given User via worklist iteration and populate
75// the set of GlobalValue references encountered. Invoked either on an
76// Instruction or a GlobalVariable (which walks its initializer).
Peter Collingbourne9667b912017-05-04 18:03:25 +000077static void findRefEdges(ModuleSummaryIndex &Index, const User *CurUser,
78 SetVector<ValueInfo> &RefEdges,
Teresa Johnson2d5487c2016-04-11 13:58:45 +000079 SmallPtrSet<const User *, 8> &Visited) {
80 SmallVector<const User *, 32> Worklist;
81 Worklist.push_back(CurUser);
82
83 while (!Worklist.empty()) {
84 const User *U = Worklist.pop_back_val();
85
86 if (!Visited.insert(U).second)
87 continue;
88
89 ImmutableCallSite CS(U);
90
91 for (const auto &OI : U->operands()) {
92 const User *Operand = dyn_cast<User>(OI);
93 if (!Operand)
94 continue;
95 if (isa<BlockAddress>(Operand))
96 continue;
Peter Collingbourne0c30f082016-12-20 21:12:28 +000097 if (auto *GV = dyn_cast<GlobalValue>(Operand)) {
Teresa Johnson2d5487c2016-04-11 13:58:45 +000098 // We have a reference to a global value. This should be added to
99 // the reference set unless it is a callee. Callees are handled
100 // specially by WriteFunction and are added to a separate list.
101 if (!(CS && CS.isCallee(&OI)))
Peter Collingbourne9667b912017-05-04 18:03:25 +0000102 RefEdges.insert(Index.getOrInsertValueInfo(GV));
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000103 continue;
104 }
105 Worklist.push_back(Operand);
106 }
107 }
108}
109
Piotr Padlewskid9830eb2016-09-26 20:37:32 +0000110static CalleeInfo::HotnessType getHotness(uint64_t ProfileCount,
111 ProfileSummaryInfo *PSI) {
112 if (!PSI)
113 return CalleeInfo::HotnessType::Unknown;
114 if (PSI->isHotCount(ProfileCount))
115 return CalleeInfo::HotnessType::Hot;
116 if (PSI->isColdCount(ProfileCount))
117 return CalleeInfo::HotnessType::Cold;
118 return CalleeInfo::HotnessType::None;
119}
120
Teresa Johnson519465b2017-01-05 14:32:16 +0000121static bool isNonRenamableLocal(const GlobalValue &GV) {
122 return GV.hasSection() && GV.hasLocalLinkage();
123}
124
Peter Collingbournebe9ffaa2017-02-10 22:29:38 +0000125/// Determine whether this call has all constant integer arguments (excluding
126/// "this") and summarize it to VCalls or ConstVCalls as appropriate.
127static void addVCallToSet(DevirtCallSite Call, GlobalValue::GUID Guid,
128 SetVector<FunctionSummary::VFuncId> &VCalls,
129 SetVector<FunctionSummary::ConstVCall> &ConstVCalls) {
130 std::vector<uint64_t> Args;
131 // Start from the second argument to skip the "this" pointer.
132 for (auto &Arg : make_range(Call.CS.arg_begin() + 1, Call.CS.arg_end())) {
133 auto *CI = dyn_cast<ConstantInt>(Arg);
134 if (!CI || CI->getBitWidth() > 64) {
135 VCalls.insert({Guid, Call.Offset});
136 return;
137 }
138 Args.push_back(CI->getZExtValue());
139 }
140 ConstVCalls.insert({{Guid, Call.Offset}, std::move(Args)});
141}
142
143/// If this intrinsic call requires that we add information to the function
144/// summary, do so via the non-constant reference arguments.
145static void addIntrinsicToSummary(
146 const CallInst *CI, SetVector<GlobalValue::GUID> &TypeTests,
147 SetVector<FunctionSummary::VFuncId> &TypeTestAssumeVCalls,
148 SetVector<FunctionSummary::VFuncId> &TypeCheckedLoadVCalls,
149 SetVector<FunctionSummary::ConstVCall> &TypeTestAssumeConstVCalls,
150 SetVector<FunctionSummary::ConstVCall> &TypeCheckedLoadConstVCalls) {
151 switch (CI->getCalledFunction()->getIntrinsicID()) {
152 case Intrinsic::type_test: {
153 auto *TypeMDVal = cast<MetadataAsValue>(CI->getArgOperand(1));
154 auto *TypeId = dyn_cast<MDString>(TypeMDVal->getMetadata());
155 if (!TypeId)
156 break;
157 GlobalValue::GUID Guid = GlobalValue::getGUID(TypeId->getString());
158
159 // Produce a summary from type.test intrinsics. We only summarize type.test
160 // intrinsics that are used other than by an llvm.assume intrinsic.
161 // Intrinsics that are assumed are relevant only to the devirtualization
162 // pass, not the type test lowering pass.
163 bool HasNonAssumeUses = llvm::any_of(CI->uses(), [](const Use &CIU) {
164 auto *AssumeCI = dyn_cast<CallInst>(CIU.getUser());
165 if (!AssumeCI)
166 return true;
167 Function *F = AssumeCI->getCalledFunction();
168 return !F || F->getIntrinsicID() != Intrinsic::assume;
169 });
170 if (HasNonAssumeUses)
171 TypeTests.insert(Guid);
172
173 SmallVector<DevirtCallSite, 4> DevirtCalls;
174 SmallVector<CallInst *, 4> Assumes;
175 findDevirtualizableCallsForTypeTest(DevirtCalls, Assumes, CI);
176 for (auto &Call : DevirtCalls)
177 addVCallToSet(Call, Guid, TypeTestAssumeVCalls,
178 TypeTestAssumeConstVCalls);
179
180 break;
181 }
182
183 case Intrinsic::type_checked_load: {
184 auto *TypeMDVal = cast<MetadataAsValue>(CI->getArgOperand(2));
185 auto *TypeId = dyn_cast<MDString>(TypeMDVal->getMetadata());
186 if (!TypeId)
187 break;
188 GlobalValue::GUID Guid = GlobalValue::getGUID(TypeId->getString());
189
190 SmallVector<DevirtCallSite, 4> DevirtCalls;
191 SmallVector<Instruction *, 4> LoadedPtrs;
192 SmallVector<Instruction *, 4> Preds;
193 bool HasNonCallUses = false;
194 findDevirtualizableCallsForTypeCheckedLoad(DevirtCalls, LoadedPtrs, Preds,
195 HasNonCallUses, CI);
196 // Any non-call uses of the result of llvm.type.checked.load will
197 // prevent us from optimizing away the llvm.type.test.
198 if (HasNonCallUses)
199 TypeTests.insert(Guid);
200 for (auto &Call : DevirtCalls)
201 addVCallToSet(Call, Guid, TypeCheckedLoadVCalls,
202 TypeCheckedLoadConstVCalls);
203
204 break;
205 }
206 default:
207 break;
208 }
209}
210
Teresa Johnson519465b2017-01-05 14:32:16 +0000211static void
212computeFunctionSummary(ModuleSummaryIndex &Index, const Module &M,
213 const Function &F, BlockFrequencyInfo *BFI,
Peter Collingbourne5e8b94c12017-09-01 16:24:02 +0000214 ProfileSummaryInfo *PSI, bool HasLocalsInUsedOrAsm,
Teresa Johnsone27b0582017-01-05 14:59:56 +0000215 DenseSet<GlobalValue::GUID> &CantBePromoted) {
Teresa Johnson02563cd2016-10-28 02:39:38 +0000216 // Summary not currently supported for anonymous functions, they should
217 // have been named.
218 assert(F.hasName());
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000219
220 unsigned NumInsts = 0;
221 // Map from callee ValueId to profile count. Used to accumulate profile
222 // counts for all static calls to a given callee.
Peter Collingbourne0c30f082016-12-20 21:12:28 +0000223 MapVector<ValueInfo, CalleeInfo> CallGraphEdges;
224 SetVector<ValueInfo> RefEdges;
Peter Collingbourne1b4137a72016-12-21 23:03:45 +0000225 SetVector<GlobalValue::GUID> TypeTests;
Peter Collingbournebe9ffaa2017-02-10 22:29:38 +0000226 SetVector<FunctionSummary::VFuncId> TypeTestAssumeVCalls,
227 TypeCheckedLoadVCalls;
228 SetVector<FunctionSummary::ConstVCall> TypeTestAssumeConstVCalls,
229 TypeCheckedLoadConstVCalls;
Teresa Johnsoncd21a642016-07-17 14:47:01 +0000230 ICallPromotionAnalysis ICallAnalysis;
Peter Collingbourne681fbb62017-09-07 05:35:35 +0000231 SmallPtrSet<const User *, 8> Visited;
232
233 // Add personality function, prefix data and prologue data to function's ref
234 // list.
235 findRefEdges(Index, &F, RefEdges, Visited);
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000236
Teresa Johnsond5033a42016-11-14 16:40:19 +0000237 bool HasInlineAsmMaybeReferencingInternal = false;
Benjamin Krameraa209152016-06-26 17:27:42 +0000238 for (const BasicBlock &BB : F)
239 for (const Instruction &I : BB) {
Piotr Padlewski442d38c2016-08-30 00:46:26 +0000240 if (isa<DbgInfoIntrinsic>(I))
241 continue;
242 ++NumInsts;
Peter Collingbourne9667b912017-05-04 18:03:25 +0000243 findRefEdges(Index, &I, RefEdges, Visited);
Piotr Padlewski442d38c2016-08-30 00:46:26 +0000244 auto CS = ImmutableCallSite(&I);
245 if (!CS)
246 continue;
Teresa Johnsonbf28c8f2016-10-30 05:40:44 +0000247
248 const auto *CI = dyn_cast<CallInst>(&I);
249 // Since we don't know exactly which local values are referenced in inline
Teresa Johnsond5033a42016-11-14 16:40:19 +0000250 // assembly, conservatively mark the function as possibly referencing
251 // a local value from inline assembly to ensure we don't export a
252 // reference (which would require renaming and promotion of the
253 // referenced value).
Peter Collingbourne5e8b94c12017-09-01 16:24:02 +0000254 if (HasLocalsInUsedOrAsm && CI && CI->isInlineAsm())
Teresa Johnsond5033a42016-11-14 16:40:19 +0000255 HasInlineAsmMaybeReferencingInternal = true;
Teresa Johnsonbf28c8f2016-10-30 05:40:44 +0000256
Teresa Johnson897bab92016-10-08 16:11:42 +0000257 auto *CalledValue = CS.getCalledValue();
Piotr Padlewski442d38c2016-08-30 00:46:26 +0000258 auto *CalledFunction = CS.getCalledFunction();
Volodymyr Sapsaia7396022017-11-10 00:47:47 +0000259 if (CalledValue && !CalledFunction) {
260 CalledValue = CalledValue->stripPointerCastsNoFollowAliases();
261 // Stripping pointer casts can reveal a called function.
262 CalledFunction = dyn_cast<Function>(CalledValue);
263 }
Teresa Johnson897bab92016-10-08 16:11:42 +0000264 // Check if this is an alias to a function. If so, get the
265 // called aliasee for the checks below.
266 if (auto *GA = dyn_cast<GlobalAlias>(CalledValue)) {
267 assert(!CalledFunction && "Expected null called function in callsite for alias");
268 CalledFunction = dyn_cast<Function>(GA->getBaseObject());
269 }
Peter Collingbourne1b4137a72016-12-21 23:03:45 +0000270 // Check if this is a direct call to a known function or a known
271 // intrinsic, or an indirect call with profile data.
Piotr Padlewski442d38c2016-08-30 00:46:26 +0000272 if (CalledFunction) {
Peter Collingbournebe9ffaa2017-02-10 22:29:38 +0000273 if (CI && CalledFunction->isIntrinsic()) {
274 addIntrinsicToSummary(
275 CI, TypeTests, TypeTestAssumeVCalls, TypeCheckedLoadVCalls,
276 TypeTestAssumeConstVCalls, TypeCheckedLoadConstVCalls);
277 continue;
Peter Collingbourne1b4137a72016-12-21 23:03:45 +0000278 }
Teresa Johnson02563cd2016-10-28 02:39:38 +0000279 // We should have named any anonymous globals
280 assert(CalledFunction->hasName());
Easwaran Ramanf5f91602017-05-09 23:21:10 +0000281 auto ScaledCount = PSI->getProfileCount(&I, BFI);
Peter Collingbourne0c30f082016-12-20 21:12:28 +0000282 auto Hotness = ScaledCount ? getHotness(ScaledCount.getValue(), PSI)
283 : CalleeInfo::HotnessType::Unknown;
Teresa Johnsondb83ace2018-03-31 00:18:08 +0000284 if (ForceSummaryEdgesCold != FunctionSummary::FSHT_None)
285 Hotness = CalleeInfo::HotnessType::Cold;
Peter Collingbourne0c30f082016-12-20 21:12:28 +0000286
Teresa Johnson897bab92016-10-08 16:11:42 +0000287 // Use the original CalledValue, in case it was an alias. We want
288 // to record the call edge to the alias in that case. Eventually
289 // an alias summary will be created to associate the alias and
290 // aliasee.
Easwaran Ramanc73cec82018-01-25 19:27:17 +0000291 auto &ValueInfo = CallGraphEdges[Index.getOrInsertValueInfo(
292 cast<GlobalValue>(CalledValue))];
293 ValueInfo.updateHotness(Hotness);
294 // Add the relative block frequency to CalleeInfo if there is no profile
295 // information.
296 if (BFI != nullptr && Hotness == CalleeInfo::HotnessType::Unknown) {
Easwaran Raman385d8ea2018-02-22 19:44:08 +0000297 uint64_t BBFreq = BFI->getBlockFreq(&BB).getFrequency();
298 uint64_t EntryFreq = BFI->getEntryFreq();
299 ValueInfo.updateRelBlockFreq(BBFreq, EntryFreq);
Easwaran Ramanc73cec82018-01-25 19:27:17 +0000300 }
Piotr Padlewski442d38c2016-08-30 00:46:26 +0000301 } else {
Piotr Padlewski442d38c2016-08-30 00:46:26 +0000302 // Skip inline assembly calls.
303 if (CI && CI->isInlineAsm())
304 continue;
Volodymyr Sapsai8b46ff12017-11-17 18:28:05 +0000305 // Skip direct calls.
306 if (!CalledValue || isa<Constant>(CalledValue))
307 continue;
Piotr Padlewski442d38c2016-08-30 00:46:26 +0000308
Taewook Oh7646e772018-03-13 04:26:58 +0000309 // Check if the instruction has a callees metadata. If so, add callees
310 // to CallGraphEdges to reflect the references from the metadata, and
311 // to enable importing for subsequent indirect call promotion and
312 // inlining.
313 if (auto *MD = I.getMetadata(LLVMContext::MD_callees)) {
314 for (auto &Op : MD->operands()) {
315 Function *Callee = mdconst::extract_or_null<Function>(Op);
316 if (Callee)
317 CallGraphEdges[Index.getOrInsertValueInfo(Callee)];
318 }
319 }
320
Piotr Padlewski442d38c2016-08-30 00:46:26 +0000321 uint32_t NumVals, NumCandidates;
322 uint64_t TotalCount;
323 auto CandidateProfileData =
324 ICallAnalysis.getPromotionCandidatesForInstruction(
325 &I, NumVals, TotalCount, NumCandidates);
326 for (auto &Candidate : CandidateProfileData)
Peter Collingbourne9667b912017-05-04 18:03:25 +0000327 CallGraphEdges[Index.getOrInsertValueInfo(Candidate.Value)]
328 .updateHotness(getHotness(Candidate.Count, PSI));
Piotr Padlewski442d38c2016-08-30 00:46:26 +0000329 }
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000330 }
331
Dehao Chena60cdd32017-02-28 18:09:44 +0000332 // Explicit add hot edges to enforce importing for designated GUIDs for
333 // sample PGO, to enable the same inlines as the profiled optimized binary.
334 for (auto &I : F.getImportGUIDs())
Peter Collingbourne9667b912017-05-04 18:03:25 +0000335 CallGraphEdges[Index.getOrInsertValueInfo(I)].updateHotness(
Teresa Johnsondb83ace2018-03-31 00:18:08 +0000336 ForceSummaryEdgesCold == FunctionSummary::FSHT_All
337 ? CalleeInfo::HotnessType::Cold
338 : CalleeInfo::HotnessType::Critical);
Dehao Chena60cdd32017-02-28 18:09:44 +0000339
Teresa Johnson519465b2017-01-05 14:32:16 +0000340 bool NonRenamableLocal = isNonRenamableLocal(F);
341 bool NotEligibleForImport =
342 NonRenamableLocal || HasInlineAsmMaybeReferencingInternal ||
343 // Inliner doesn't handle variadic functions.
344 // FIXME: refactor this to use the same code that inliner is using.
Eugene Leviant193e7012017-12-25 13:57:24 +0000345 F.isVarArg() ||
346 // Don't try to import functions with noinline attribute.
347 F.getAttributes().hasFnAttribute(Attribute::NoInline);
Teresa Johnson6c475a72017-01-05 21:34:18 +0000348 GlobalValueSummary::GVFlags Flags(F.getLinkage(), NotEligibleForImport,
Sean Fertile4595a912017-11-04 17:04:39 +0000349 /* Live = */ false, F.isDSOLocal());
Charles Saternos75da10d2017-08-04 16:00:58 +0000350 FunctionSummary::FFlags FunFlags{
351 F.hasFnAttribute(Attribute::ReadNone),
352 F.hasFnAttribute(Attribute::ReadOnly),
353 F.hasFnAttribute(Attribute::NoRecurse),
354 F.returnDoesNotAlias(),
355 };
Peter Collingbourne0c30f082016-12-20 21:12:28 +0000356 auto FuncSummary = llvm::make_unique<FunctionSummary>(
Charles Saternos75da10d2017-08-04 16:00:58 +0000357 Flags, NumInsts, FunFlags, RefEdges.takeVector(),
358 CallGraphEdges.takeVector(), TypeTests.takeVector(),
359 TypeTestAssumeVCalls.takeVector(), TypeCheckedLoadVCalls.takeVector(),
Peter Collingbournebe9ffaa2017-02-10 22:29:38 +0000360 TypeTestAssumeConstVCalls.takeVector(),
361 TypeCheckedLoadConstVCalls.takeVector());
Teresa Johnson519465b2017-01-05 14:32:16 +0000362 if (NonRenamableLocal)
363 CantBePromoted.insert(F.getGUID());
Teresa Johnson7bea1aa2018-06-26 00:20:49 +0000364 Index.addGlobalValueSummary(F, std::move(FuncSummary));
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000365}
366
Teresa Johnson519465b2017-01-05 14:32:16 +0000367static void
368computeVariableSummary(ModuleSummaryIndex &Index, const GlobalVariable &V,
Teresa Johnsone27b0582017-01-05 14:59:56 +0000369 DenseSet<GlobalValue::GUID> &CantBePromoted) {
Peter Collingbourne0c30f082016-12-20 21:12:28 +0000370 SetVector<ValueInfo> RefEdges;
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000371 SmallPtrSet<const User *, 8> Visited;
Peter Collingbourne9667b912017-05-04 18:03:25 +0000372 findRefEdges(Index, &V, RefEdges, Visited);
Teresa Johnson519465b2017-01-05 14:32:16 +0000373 bool NonRenamableLocal = isNonRenamableLocal(V);
Teresa Johnson6c475a72017-01-05 21:34:18 +0000374 GlobalValueSummary::GVFlags Flags(V.getLinkage(), NonRenamableLocal,
Sean Fertile4595a912017-11-04 17:04:39 +0000375 /* Live = */ false, V.isDSOLocal());
Peter Collingbourne0c30f082016-12-20 21:12:28 +0000376 auto GVarSummary =
377 llvm::make_unique<GlobalVarSummary>(Flags, RefEdges.takeVector());
Teresa Johnson519465b2017-01-05 14:32:16 +0000378 if (NonRenamableLocal)
379 CantBePromoted.insert(V.getGUID());
Teresa Johnson7bea1aa2018-06-26 00:20:49 +0000380 Index.addGlobalValueSummary(V, std::move(GVarSummary));
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000381}
382
Teresa Johnson519465b2017-01-05 14:32:16 +0000383static void
384computeAliasSummary(ModuleSummaryIndex &Index, const GlobalAlias &A,
Teresa Johnsone27b0582017-01-05 14:59:56 +0000385 DenseSet<GlobalValue::GUID> &CantBePromoted) {
Teresa Johnson519465b2017-01-05 14:32:16 +0000386 bool NonRenamableLocal = isNonRenamableLocal(A);
Teresa Johnson6c475a72017-01-05 21:34:18 +0000387 GlobalValueSummary::GVFlags Flags(A.getLinkage(), NonRenamableLocal,
Sean Fertile4595a912017-11-04 17:04:39 +0000388 /* Live = */ false, A.isDSOLocal());
Teresa Johnsoncbdc5ff2017-09-13 17:10:24 +0000389 auto AS = llvm::make_unique<AliasSummary>(Flags);
Teresa Johnson02563cd2016-10-28 02:39:38 +0000390 auto *Aliasee = A.getBaseObject();
391 auto *AliaseeSummary = Index.getGlobalValueSummary(*Aliasee);
392 assert(AliaseeSummary && "Alias expects aliasee summary to be parsed");
393 AS->setAliasee(AliaseeSummary);
Teresa Johnson519465b2017-01-05 14:32:16 +0000394 if (NonRenamableLocal)
395 CantBePromoted.insert(A.getGUID());
Teresa Johnson7bea1aa2018-06-26 00:20:49 +0000396 Index.addGlobalValueSummary(A, std::move(AS));
Teresa Johnson02563cd2016-10-28 02:39:38 +0000397}
398
Teresa Johnson6c475a72017-01-05 21:34:18 +0000399// Set LiveRoot flag on entries matching the given value name.
400static void setLiveRoot(ModuleSummaryIndex &Index, StringRef Name) {
Peter Collingbourne9667b912017-05-04 18:03:25 +0000401 if (ValueInfo VI = Index.getValueInfo(GlobalValue::getGUID(Name)))
402 for (auto &Summary : VI.getSummaryList())
Evgeniy Stepanov56584bb2017-06-01 20:30:06 +0000403 Summary->setLive(true);
Teresa Johnson6c475a72017-01-05 21:34:18 +0000404}
405
Chandler Carruthb7be5b62016-08-19 07:49:19 +0000406ModuleSummaryIndex llvm::buildModuleSummaryIndex(
407 const Module &M,
Piotr Padlewskid9830eb2016-09-26 20:37:32 +0000408 std::function<BlockFrequencyInfo *(const Function &F)> GetBFICallback,
409 ProfileSummaryInfo *PSI) {
Teresa Johnson94624ac2017-05-10 18:52:16 +0000410 assert(PSI);
Teresa Johnson4ffc3e72018-06-06 22:22:01 +0000411 ModuleSummaryIndex Index(/*HaveGVs=*/true);
Teresa Johnsonbf28c8f2016-10-30 05:40:44 +0000412
Teresa Johnsona0811452016-11-10 16:57:32 +0000413 // Identify the local values in the llvm.used and llvm.compiler.used sets,
414 // which should not be exported as they would then require renaming and
415 // promotion, but we may have opaque uses e.g. in inline asm. We collect them
416 // here because we use this information to mark functions containing inline
417 // assembly calls as not importable.
Mehdi Aminib6a11a72016-11-09 01:45:13 +0000418 SmallPtrSet<GlobalValue *, 8> LocalsUsed;
Teresa Johnsona0811452016-11-10 16:57:32 +0000419 SmallPtrSet<GlobalValue *, 8> Used;
420 // First collect those in the llvm.used set.
421 collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
Teresa Johnsona0811452016-11-10 16:57:32 +0000422 // Next collect those in the llvm.compiler.used set.
423 collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ true);
Teresa Johnsone27b0582017-01-05 14:59:56 +0000424 DenseSet<GlobalValue::GUID> CantBePromoted;
Teresa Johnsonbf28c8f2016-10-30 05:40:44 +0000425 for (auto *V : Used) {
Teresa Johnson519465b2017-01-05 14:32:16 +0000426 if (V->hasLocalLinkage()) {
Teresa Johnsonbf28c8f2016-10-30 05:40:44 +0000427 LocalsUsed.insert(V);
Teresa Johnson519465b2017-01-05 14:32:16 +0000428 CantBePromoted.insert(V->getGUID());
429 }
Teresa Johnsonbf28c8f2016-10-30 05:40:44 +0000430 }
Teresa Johnsonb35cc692016-04-20 14:39:45 +0000431
Peter Collingbourne5e8b94c12017-09-01 16:24:02 +0000432 bool HasLocalInlineAsmSymbol = false;
433 if (!M.getModuleInlineAsm().empty()) {
434 // Collect the local values defined by module level asm, and set up
435 // summaries for these symbols so that they can be marked as NoRename,
436 // to prevent export of any use of them in regular IR that would require
437 // renaming within the module level asm. Note we don't need to create a
438 // summary for weak or global defs, as they don't need to be flagged as
439 // NoRename, and defs in module level asm can't be imported anyway.
440 // Also, any values used but not defined within module level asm should
441 // be listed on the llvm.used or llvm.compiler.used global and marked as
442 // referenced from there.
443 ModuleSymbolTable::CollectAsmSymbols(
444 M, [&](StringRef Name, object::BasicSymbolRef::Flags Flags) {
445 // Symbols not marked as Weak or Global are local definitions.
446 if (Flags & (object::BasicSymbolRef::SF_Weak |
447 object::BasicSymbolRef::SF_Global))
448 return;
449 HasLocalInlineAsmSymbol = true;
450 GlobalValue *GV = M.getNamedValue(Name);
451 if (!GV)
452 return;
453 assert(GV->isDeclaration() && "Def in module asm already has definition");
454 GlobalValueSummary::GVFlags GVFlags(GlobalValue::InternalLinkage,
455 /* NotEligibleToImport = */ true,
Sean Fertile4595a912017-11-04 17:04:39 +0000456 /* Live = */ true,
457 /* Local */ GV->isDSOLocal());
Teresa Johnson7bea1aa2018-06-26 00:20:49 +0000458 CantBePromoted.insert(GV->getGUID());
Peter Collingbourne5e8b94c12017-09-01 16:24:02 +0000459 // Create the appropriate summary type.
460 if (Function *F = dyn_cast<Function>(GV)) {
461 std::unique_ptr<FunctionSummary> Summary =
462 llvm::make_unique<FunctionSummary>(
463 GVFlags, 0,
464 FunctionSummary::FFlags{
465 F->hasFnAttribute(Attribute::ReadNone),
466 F->hasFnAttribute(Attribute::ReadOnly),
467 F->hasFnAttribute(Attribute::NoRecurse),
468 F->returnDoesNotAlias()},
469 ArrayRef<ValueInfo>{}, ArrayRef<FunctionSummary::EdgeTy>{},
470 ArrayRef<GlobalValue::GUID>{},
471 ArrayRef<FunctionSummary::VFuncId>{},
472 ArrayRef<FunctionSummary::VFuncId>{},
473 ArrayRef<FunctionSummary::ConstVCall>{},
474 ArrayRef<FunctionSummary::ConstVCall>{});
Teresa Johnson7bea1aa2018-06-26 00:20:49 +0000475 Index.addGlobalValueSummary(*GV, std::move(Summary));
Peter Collingbourne5e8b94c12017-09-01 16:24:02 +0000476 } else {
477 std::unique_ptr<GlobalVarSummary> Summary =
478 llvm::make_unique<GlobalVarSummary>(GVFlags,
479 ArrayRef<ValueInfo>{});
Teresa Johnson7bea1aa2018-06-26 00:20:49 +0000480 Index.addGlobalValueSummary(*GV, std::move(Summary));
Peter Collingbourne5e8b94c12017-09-01 16:24:02 +0000481 }
482 });
483 }
484
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000485 // Compute summaries for all functions defined in module, and save in the
486 // index.
Chandler Carruthb7be5b62016-08-19 07:49:19 +0000487 for (auto &F : M) {
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000488 if (F.isDeclaration())
489 continue;
490
491 BlockFrequencyInfo *BFI = nullptr;
492 std::unique_ptr<BlockFrequencyInfo> BFIPtr;
Chandler Carruthb7be5b62016-08-19 07:49:19 +0000493 if (GetBFICallback)
494 BFI = GetBFICallback(F);
Easwaran Ramana17f2202017-12-22 01:33:52 +0000495 else if (F.hasProfileData()) {
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000496 LoopInfo LI{DominatorTree(const_cast<Function &>(F))};
497 BranchProbabilityInfo BPI{F, LI};
498 BFIPtr = llvm::make_unique<BlockFrequencyInfo>(F, BPI, LI);
499 BFI = BFIPtr.get();
500 }
501
Peter Collingbourne5e8b94c12017-09-01 16:24:02 +0000502 computeFunctionSummary(Index, M, F, BFI, PSI,
503 !LocalsUsed.empty() || HasLocalInlineAsmSymbol,
Teresa Johnson519465b2017-01-05 14:32:16 +0000504 CantBePromoted);
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000505 }
506
507 // Compute summaries for all variables defined in module, and save in the
508 // index.
Chandler Carruthb7be5b62016-08-19 07:49:19 +0000509 for (const GlobalVariable &G : M.globals()) {
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000510 if (G.isDeclaration())
511 continue;
Teresa Johnson519465b2017-01-05 14:32:16 +0000512 computeVariableSummary(Index, G, CantBePromoted);
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000513 }
Teresa Johnson02563cd2016-10-28 02:39:38 +0000514
515 // Compute summaries for all aliases defined in module, and save in the
516 // index.
517 for (const GlobalAlias &A : M.aliases())
Teresa Johnson519465b2017-01-05 14:32:16 +0000518 computeAliasSummary(Index, A, CantBePromoted);
Teresa Johnson02563cd2016-10-28 02:39:38 +0000519
Teresa Johnsonbf28c8f2016-10-30 05:40:44 +0000520 for (auto *V : LocalsUsed) {
521 auto *Summary = Index.getGlobalValueSummary(*V);
522 assert(Summary && "Missing summary for global value");
Teresa Johnson519465b2017-01-05 14:32:16 +0000523 Summary->setNotEligibleToImport();
Teresa Johnsonbf28c8f2016-10-30 05:40:44 +0000524 }
525
Teresa Johnson6c475a72017-01-05 21:34:18 +0000526 // The linker doesn't know about these LLVM produced values, so we need
527 // to flag them as live in the index to ensure index-based dead value
528 // analysis treats them as live roots of the analysis.
529 setLiveRoot(Index, "llvm.used");
530 setLiveRoot(Index, "llvm.compiler.used");
531 setLiveRoot(Index, "llvm.global_ctors");
532 setLiveRoot(Index, "llvm.global_dtors");
533 setLiveRoot(Index, "llvm.global.annotations");
534
Peter Collingbournee357fbd2017-06-08 23:01:49 +0000535 bool IsThinLTO = true;
536 if (auto *MD =
537 mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("ThinLTO")))
538 IsThinLTO = MD->getZExtValue();
539
Teresa Johnson519465b2017-01-05 14:32:16 +0000540 for (auto &GlobalList : Index) {
Peter Collingbourne9667b912017-05-04 18:03:25 +0000541 // Ignore entries for references that are undefined in the current module.
542 if (GlobalList.second.SummaryList.empty())
543 continue;
544
545 assert(GlobalList.second.SummaryList.size() == 1 &&
Teresa Johnson519465b2017-01-05 14:32:16 +0000546 "Expected module's index to have one summary per GUID");
Peter Collingbourne9667b912017-05-04 18:03:25 +0000547 auto &Summary = GlobalList.second.SummaryList[0];
Peter Collingbournee357fbd2017-06-08 23:01:49 +0000548 if (!IsThinLTO) {
549 Summary->setNotEligibleToImport();
550 continue;
551 }
552
Teresa Johnson519465b2017-01-05 14:32:16 +0000553 bool AllRefsCanBeExternallyReferenced =
554 llvm::all_of(Summary->refs(), [&](const ValueInfo &VI) {
Peter Collingbourne9667b912017-05-04 18:03:25 +0000555 return !CantBePromoted.count(VI.getGUID());
Teresa Johnson519465b2017-01-05 14:32:16 +0000556 });
557 if (!AllRefsCanBeExternallyReferenced) {
558 Summary->setNotEligibleToImport();
559 continue;
560 }
561
562 if (auto *FuncSummary = dyn_cast<FunctionSummary>(Summary.get())) {
563 bool AllCallsCanBeExternallyReferenced = llvm::all_of(
564 FuncSummary->calls(), [&](const FunctionSummary::EdgeTy &Edge) {
Peter Collingbourne9667b912017-05-04 18:03:25 +0000565 return !CantBePromoted.count(Edge.first.getGUID());
Teresa Johnson519465b2017-01-05 14:32:16 +0000566 });
567 if (!AllCallsCanBeExternallyReferenced)
568 Summary->setNotEligibleToImport();
569 }
570 }
571
Chandler Carruthb7be5b62016-08-19 07:49:19 +0000572 return Index;
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000573}
574
Chandler Carruthdab4eae2016-11-23 17:53:26 +0000575AnalysisKey ModuleSummaryIndexAnalysis::Key;
Teresa Johnsonf93b2462016-08-12 13:53:02 +0000576
Chandler Carruthb7be5b62016-08-19 07:49:19 +0000577ModuleSummaryIndex
Teresa Johnsonf93b2462016-08-12 13:53:02 +0000578ModuleSummaryIndexAnalysis::run(Module &M, ModuleAnalysisManager &AM) {
Piotr Padlewskid9830eb2016-09-26 20:37:32 +0000579 ProfileSummaryInfo &PSI = AM.getResult<ProfileSummaryAnalysis>(M);
Teresa Johnsonf93b2462016-08-12 13:53:02 +0000580 auto &FAM = AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
Piotr Padlewskid9830eb2016-09-26 20:37:32 +0000581 return buildModuleSummaryIndex(
582 M,
583 [&FAM](const Function &F) {
584 return &FAM.getResult<BlockFrequencyAnalysis>(
585 *const_cast<Function *>(&F));
586 },
587 &PSI);
Teresa Johnsonf93b2462016-08-12 13:53:02 +0000588}
589
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000590char ModuleSummaryIndexWrapperPass::ID = 0;
Eugene Zelenkobb1b2d02017-08-16 22:07:40 +0000591
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000592INITIALIZE_PASS_BEGIN(ModuleSummaryIndexWrapperPass, "module-summary-analysis",
593 "Module Summary Analysis", false, true)
594INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfoWrapperPass)
Mehdi Amini89029482017-01-21 06:01:22 +0000595INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000596INITIALIZE_PASS_END(ModuleSummaryIndexWrapperPass, "module-summary-analysis",
597 "Module Summary Analysis", false, true)
598
599ModulePass *llvm::createModuleSummaryIndexWrapperPass() {
600 return new ModuleSummaryIndexWrapperPass();
601}
602
603ModuleSummaryIndexWrapperPass::ModuleSummaryIndexWrapperPass()
604 : ModulePass(ID) {
605 initializeModuleSummaryIndexWrapperPassPass(*PassRegistry::getPassRegistry());
606}
607
608bool ModuleSummaryIndexWrapperPass::runOnModule(Module &M) {
Dehao Chen5461d8b2016-09-28 21:00:58 +0000609 auto &PSI = *getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
Teresa Johnson51905532018-06-26 02:29:08 +0000610 Index.emplace(buildModuleSummaryIndex(
Piotr Padlewskid9830eb2016-09-26 20:37:32 +0000611 M,
612 [this](const Function &F) {
613 return &(this->getAnalysis<BlockFrequencyInfoWrapperPass>(
614 *const_cast<Function *>(&F))
615 .getBFI());
616 },
Teresa Johnson51905532018-06-26 02:29:08 +0000617 &PSI));
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000618 return false;
619}
620
621bool ModuleSummaryIndexWrapperPass::doFinalization(Module &M) {
Chandler Carruthb7be5b62016-08-19 07:49:19 +0000622 Index.reset();
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000623 return false;
624}
625
626void ModuleSummaryIndexWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
627 AU.setPreservesAll();
628 AU.addRequired<BlockFrequencyInfoWrapperPass>();
Piotr Padlewskid9830eb2016-09-26 20:37:32 +0000629 AU.addRequired<ProfileSummaryInfoWrapperPass>();
Teresa Johnson2d5487c2016-04-11 13:58:45 +0000630}