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+//===- ModuleSummaryAnalysis.cpp - Module summary index builder -----------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass builds a ModuleSummaryIndex object for the module, to be written
+// to bitcode or LLVM assembly.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/ModuleSummaryAnalysis.h"
+#include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/BlockFrequencyInfo.h"
+#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
+#include "llvm/Analysis/BranchProbabilityInfo.h"
+#include "llvm/Analysis/IndirectCallPromotionAnalysis.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
+#include "llvm/Analysis/TypeMetadataUtils.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/ValueSymbolTable.h"
+#include "llvm/Object/IRObjectFile.h"
+#include "llvm/Pass.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "module-summary-analysis"
+
+// Walk through the operands of a given User via worklist iteration and populate
+// the set of GlobalValue references encountered. Invoked either on an
+// Instruction or a GlobalVariable (which walks its initializer).
+static void findRefEdges(const User *CurUser, SetVector<ValueInfo> &RefEdges,
+ SmallPtrSet<const User *, 8> &Visited) {
+ SmallVector<const User *, 32> Worklist;
+ Worklist.push_back(CurUser);
+
+ while (!Worklist.empty()) {
+ const User *U = Worklist.pop_back_val();
+
+ if (!Visited.insert(U).second)
+ continue;
+
+ ImmutableCallSite CS(U);
+
+ for (const auto &OI : U->operands()) {
+ const User *Operand = dyn_cast<User>(OI);
+ if (!Operand)
+ continue;
+ if (isa<BlockAddress>(Operand))
+ continue;
+ if (auto *GV = dyn_cast<GlobalValue>(Operand)) {
+ // We have a reference to a global value. This should be added to
+ // the reference set unless it is a callee. Callees are handled
+ // specially by WriteFunction and are added to a separate list.
+ if (!(CS && CS.isCallee(&OI)))
+ RefEdges.insert(GV);
+ continue;
+ }
+ Worklist.push_back(Operand);
+ }
+ }
+}
+
+static CalleeInfo::HotnessType getHotness(uint64_t ProfileCount,
+ ProfileSummaryInfo *PSI) {
+ if (!PSI)
+ return CalleeInfo::HotnessType::Unknown;
+ if (PSI->isHotCount(ProfileCount))
+ return CalleeInfo::HotnessType::Hot;
+ if (PSI->isColdCount(ProfileCount))
+ return CalleeInfo::HotnessType::Cold;
+ return CalleeInfo::HotnessType::None;
+}
+
+static void computeFunctionSummary(ModuleSummaryIndex &Index, const Module &M,
+ const Function &F, BlockFrequencyInfo *BFI,
+ ProfileSummaryInfo *PSI,
+ bool HasLocalsInUsed) {
+ // Summary not currently supported for anonymous functions, they should
+ // have been named.
+ assert(F.hasName());
+
+ unsigned NumInsts = 0;
+ // Map from callee ValueId to profile count. Used to accumulate profile
+ // counts for all static calls to a given callee.
+ MapVector<ValueInfo, CalleeInfo> CallGraphEdges;
+ SetVector<ValueInfo> RefEdges;
+ SetVector<GlobalValue::GUID> TypeTests;
+ ICallPromotionAnalysis ICallAnalysis;
+
+ bool HasInlineAsmMaybeReferencingInternal = false;
+ SmallPtrSet<const User *, 8> Visited;
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB) {
+ if (isa<DbgInfoIntrinsic>(I))
+ continue;
+ ++NumInsts;
+ findRefEdges(&I, RefEdges, Visited);
+ auto CS = ImmutableCallSite(&I);
+ if (!CS)
+ continue;
+
+ const auto *CI = dyn_cast<CallInst>(&I);
+ // Since we don't know exactly which local values are referenced in inline
+ // assembly, conservatively mark the function as possibly referencing
+ // a local value from inline assembly to ensure we don't export a
+ // reference (which would require renaming and promotion of the
+ // referenced value).
+ if (HasLocalsInUsed && CI && CI->isInlineAsm())
+ HasInlineAsmMaybeReferencingInternal = true;
+
+ auto *CalledValue = CS.getCalledValue();
+ auto *CalledFunction = CS.getCalledFunction();
+ // Check if this is an alias to a function. If so, get the
+ // called aliasee for the checks below.
+ if (auto *GA = dyn_cast<GlobalAlias>(CalledValue)) {
+ assert(!CalledFunction && "Expected null called function in callsite for alias");
+ CalledFunction = dyn_cast<Function>(GA->getBaseObject());
+ }
+ // Check if this is a direct call to a known function or a known
+ // intrinsic, or an indirect call with profile data.
+ if (CalledFunction) {
+ if (CalledFunction->isIntrinsic()) {
+ if (CalledFunction->getIntrinsicID() != Intrinsic::type_test)
+ continue;
+ // Produce a summary from type.test intrinsics. We only summarize
+ // type.test intrinsics that are used other than by an llvm.assume
+ // intrinsic. Intrinsics that are assumed are relevant only to the
+ // devirtualization pass, not the type test lowering pass.
+ bool HasNonAssumeUses = llvm::any_of(CI->uses(), [](const Use &CIU) {
+ auto *AssumeCI = dyn_cast<CallInst>(CIU.getUser());
+ if (!AssumeCI)
+ return true;
+ Function *F = AssumeCI->getCalledFunction();
+ return !F || F->getIntrinsicID() != Intrinsic::assume;
+ });
+ if (HasNonAssumeUses) {
+ auto *TypeMDVal = cast<MetadataAsValue>(CI->getArgOperand(1));
+ if (auto *TypeId = dyn_cast<MDString>(TypeMDVal->getMetadata()))
+ TypeTests.insert(GlobalValue::getGUID(TypeId->getString()));
+ }
+ }
+ // We should have named any anonymous globals
+ assert(CalledFunction->hasName());
+ auto ScaledCount = BFI ? BFI->getBlockProfileCount(&BB) : None;
+ auto Hotness = ScaledCount ? getHotness(ScaledCount.getValue(), PSI)
+ : CalleeInfo::HotnessType::Unknown;
+
+ // Use the original CalledValue, in case it was an alias. We want
+ // to record the call edge to the alias in that case. Eventually
+ // an alias summary will be created to associate the alias and
+ // aliasee.
+ CallGraphEdges[cast<GlobalValue>(CalledValue)].updateHotness(Hotness);
+ } else {
+ // Skip inline assembly calls.
+ if (CI && CI->isInlineAsm())
+ continue;
+ // Skip direct calls.
+ if (!CS.getCalledValue() || isa<Constant>(CS.getCalledValue()))
+ continue;
+
+ uint32_t NumVals, NumCandidates;
+ uint64_t TotalCount;
+ auto CandidateProfileData =
+ ICallAnalysis.getPromotionCandidatesForInstruction(
+ &I, NumVals, TotalCount, NumCandidates);
+ for (auto &Candidate : CandidateProfileData)
+ CallGraphEdges[Candidate.Value].updateHotness(
+ getHotness(Candidate.Count, PSI));
+ }
+ }
+
+ GlobalValueSummary::GVFlags Flags(F);
+ auto FuncSummary = llvm::make_unique<FunctionSummary>(
+ Flags, NumInsts, RefEdges.takeVector(), CallGraphEdges.takeVector(),
+ TypeTests.takeVector());
+ if (HasInlineAsmMaybeReferencingInternal)
+ FuncSummary->setHasInlineAsmMaybeReferencingInternal();
+ Index.addGlobalValueSummary(F.getName(), std::move(FuncSummary));
+}
+
+static void computeVariableSummary(ModuleSummaryIndex &Index,
+ const GlobalVariable &V) {
+ SetVector<ValueInfo> RefEdges;
+ SmallPtrSet<const User *, 8> Visited;
+ findRefEdges(&V, RefEdges, Visited);
+ GlobalValueSummary::GVFlags Flags(V);
+ auto GVarSummary =
+ llvm::make_unique<GlobalVarSummary>(Flags, RefEdges.takeVector());
+ Index.addGlobalValueSummary(V.getName(), std::move(GVarSummary));
+}
+
+static void computeAliasSummary(ModuleSummaryIndex &Index,
+ const GlobalAlias &A) {
+ GlobalValueSummary::GVFlags Flags(A);
+ auto AS = llvm::make_unique<AliasSummary>(Flags, ArrayRef<ValueInfo>{});
+ auto *Aliasee = A.getBaseObject();
+ auto *AliaseeSummary = Index.getGlobalValueSummary(*Aliasee);
+ assert(AliaseeSummary && "Alias expects aliasee summary to be parsed");
+ AS->setAliasee(AliaseeSummary);
+ Index.addGlobalValueSummary(A.getName(), std::move(AS));
+}
+
+ModuleSummaryIndex llvm::buildModuleSummaryIndex(
+ const Module &M,
+ std::function<BlockFrequencyInfo *(const Function &F)> GetBFICallback,
+ ProfileSummaryInfo *PSI) {
+ ModuleSummaryIndex Index;
+
+ // Identify the local values in the llvm.used and llvm.compiler.used sets,
+ // which should not be exported as they would then require renaming and
+ // promotion, but we may have opaque uses e.g. in inline asm. We collect them
+ // here because we use this information to mark functions containing inline
+ // assembly calls as not importable.
+ SmallPtrSet<GlobalValue *, 8> LocalsUsed;
+ SmallPtrSet<GlobalValue *, 8> Used;
+ // First collect those in the llvm.used set.
+ collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
+ // Next collect those in the llvm.compiler.used set.
+ collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ true);
+ for (auto *V : Used) {
+ if (V->hasLocalLinkage())
+ LocalsUsed.insert(V);
+ }
+
+ // Compute summaries for all functions defined in module, and save in the
+ // index.
+ for (auto &F : M) {
+ if (F.isDeclaration())
+ continue;
+
+ BlockFrequencyInfo *BFI = nullptr;
+ std::unique_ptr<BlockFrequencyInfo> BFIPtr;
+ if (GetBFICallback)
+ BFI = GetBFICallback(F);
+ else if (F.getEntryCount().hasValue()) {
+ LoopInfo LI{DominatorTree(const_cast<Function &>(F))};
+ BranchProbabilityInfo BPI{F, LI};
+ BFIPtr = llvm::make_unique<BlockFrequencyInfo>(F, BPI, LI);
+ BFI = BFIPtr.get();
+ }
+
+ computeFunctionSummary(Index, M, F, BFI, PSI, !LocalsUsed.empty());
+ }
+
+ // Compute summaries for all variables defined in module, and save in the
+ // index.
+ for (const GlobalVariable &G : M.globals()) {
+ if (G.isDeclaration())
+ continue;
+ computeVariableSummary(Index, G);
+ }
+
+ // Compute summaries for all aliases defined in module, and save in the
+ // index.
+ for (const GlobalAlias &A : M.aliases())
+ computeAliasSummary(Index, A);
+
+ for (auto *V : LocalsUsed) {
+ auto *Summary = Index.getGlobalValueSummary(*V);
+ assert(Summary && "Missing summary for global value");
+ Summary->setNoRename();
+ }
+
+ if (!M.getModuleInlineAsm().empty()) {
+ // Collect the local values defined by module level asm, and set up
+ // summaries for these symbols so that they can be marked as NoRename,
+ // to prevent export of any use of them in regular IR that would require
+ // renaming within the module level asm. Note we don't need to create a
+ // summary for weak or global defs, as they don't need to be flagged as
+ // NoRename, and defs in module level asm can't be imported anyway.
+ // Also, any values used but not defined within module level asm should
+ // be listed on the llvm.used or llvm.compiler.used global and marked as
+ // referenced from there.
+ ModuleSymbolTable::CollectAsmSymbols(
+ Triple(M.getTargetTriple()), M.getModuleInlineAsm(),
+ [&M, &Index](StringRef Name, object::BasicSymbolRef::Flags Flags) {
+ // Symbols not marked as Weak or Global are local definitions.
+ if (Flags & (object::BasicSymbolRef::SF_Weak |
+ object::BasicSymbolRef::SF_Global))
+ return;
+ GlobalValue *GV = M.getNamedValue(Name);
+ if (!GV)
+ return;
+ assert(GV->isDeclaration() && "Def in module asm already has definition");
+ GlobalValueSummary::GVFlags GVFlags(
+ GlobalValue::InternalLinkage,
+ /* NoRename */ true,
+ /* HasInlineAsmMaybeReferencingInternal */ false,
+ /* IsNotViableToInline */ true);
+ // Create the appropriate summary type.
+ if (isa<Function>(GV)) {
+ std::unique_ptr<FunctionSummary> Summary =
+ llvm::make_unique<FunctionSummary>(
+ GVFlags, 0, ArrayRef<ValueInfo>{},
+ ArrayRef<FunctionSummary::EdgeTy>{},
+ ArrayRef<GlobalValue::GUID>{});
+ Summary->setNoRename();
+ Index.addGlobalValueSummary(Name, std::move(Summary));
+ } else {
+ std::unique_ptr<GlobalVarSummary> Summary =
+ llvm::make_unique<GlobalVarSummary>(GVFlags,
+ ArrayRef<ValueInfo>{});
+ Summary->setNoRename();
+ Index.addGlobalValueSummary(Name, std::move(Summary));
+ }
+ });
+ }
+
+ return Index;
+}
+
+AnalysisKey ModuleSummaryIndexAnalysis::Key;
+
+ModuleSummaryIndex
+ModuleSummaryIndexAnalysis::run(Module &M, ModuleAnalysisManager &AM) {
+ ProfileSummaryInfo &PSI = AM.getResult<ProfileSummaryAnalysis>(M);
+ auto &FAM = AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
+ return buildModuleSummaryIndex(
+ M,
+ [&FAM](const Function &F) {
+ return &FAM.getResult<BlockFrequencyAnalysis>(
+ *const_cast<Function *>(&F));
+ },
+ &PSI);
+}
+
+char ModuleSummaryIndexWrapperPass::ID = 0;
+INITIALIZE_PASS_BEGIN(ModuleSummaryIndexWrapperPass, "module-summary-analysis",
+ "Module Summary Analysis", false, true)
+INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfoWrapperPass)
+INITIALIZE_PASS_END(ModuleSummaryIndexWrapperPass, "module-summary-analysis",
+ "Module Summary Analysis", false, true)
+
+ModulePass *llvm::createModuleSummaryIndexWrapperPass() {
+ return new ModuleSummaryIndexWrapperPass();
+}
+
+ModuleSummaryIndexWrapperPass::ModuleSummaryIndexWrapperPass()
+ : ModulePass(ID) {
+ initializeModuleSummaryIndexWrapperPassPass(*PassRegistry::getPassRegistry());
+}
+
+bool ModuleSummaryIndexWrapperPass::runOnModule(Module &M) {
+ auto &PSI = *getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
+ Index = buildModuleSummaryIndex(
+ M,
+ [this](const Function &F) {
+ return &(this->getAnalysis<BlockFrequencyInfoWrapperPass>(
+ *const_cast<Function *>(&F))
+ .getBFI());
+ },
+ &PSI);
+ return false;
+}
+
+bool ModuleSummaryIndexWrapperPass::doFinalization(Module &M) {
+ Index.reset();
+ return false;
+}
+
+void ModuleSummaryIndexWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ AU.addRequired<BlockFrequencyInfoWrapperPass>();
+ AU.addRequired<ProfileSummaryInfoWrapperPass>();
+}
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