summaryrefslogtreecommitdiff
path: root/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'llvm/lib/Bitcode/Writer/ValueEnumerator.cpp')
-rw-r--r--llvm/lib/Bitcode/Writer/ValueEnumerator.cpp1041
1 files changed, 1041 insertions, 0 deletions
diff --git a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
new file mode 100644
index 000000000000..f59c906c7b75
--- /dev/null
+++ b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
@@ -0,0 +1,1041 @@
+//===- ValueEnumerator.cpp - Number values and types for bitcode writer ---===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the ValueEnumerator class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ValueEnumerator.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Config/llvm-config.h"
+#include "llvm/IR/Argument.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Constant.h"
+#include "llvm/IR/DebugInfoMetadata.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/GlobalAlias.h"
+#include "llvm/IR/GlobalIFunc.h"
+#include "llvm/IR/GlobalObject.h"
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Type.h"
+#include "llvm/IR/Use.h"
+#include "llvm/IR/UseListOrder.h"
+#include "llvm/IR/User.h"
+#include "llvm/IR/Value.h"
+#include "llvm/IR/ValueSymbolTable.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <iterator>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+using namespace llvm;
+
+namespace {
+
+struct OrderMap {
+ DenseMap<const Value *, std::pair<unsigned, bool>> IDs;
+ unsigned LastGlobalConstantID = 0;
+ unsigned LastGlobalValueID = 0;
+
+ OrderMap() = default;
+
+ bool isGlobalConstant(unsigned ID) const {
+ return ID <= LastGlobalConstantID;
+ }
+
+ bool isGlobalValue(unsigned ID) const {
+ return ID <= LastGlobalValueID && !isGlobalConstant(ID);
+ }
+
+ unsigned size() const { return IDs.size(); }
+ std::pair<unsigned, bool> &operator[](const Value *V) { return IDs[V]; }
+
+ std::pair<unsigned, bool> lookup(const Value *V) const {
+ return IDs.lookup(V);
+ }
+
+ void index(const Value *V) {
+ // Explicitly sequence get-size and insert-value operations to avoid UB.
+ unsigned ID = IDs.size() + 1;
+ IDs[V].first = ID;
+ }
+};
+
+} // end anonymous namespace
+
+static void orderValue(const Value *V, OrderMap &OM) {
+ if (OM.lookup(V).first)
+ return;
+
+ if (const Constant *C = dyn_cast<Constant>(V))
+ if (C->getNumOperands() && !isa<GlobalValue>(C))
+ for (const Value *Op : C->operands())
+ if (!isa<BasicBlock>(Op) && !isa<GlobalValue>(Op))
+ orderValue(Op, OM);
+
+ // Note: we cannot cache this lookup above, since inserting into the map
+ // changes the map's size, and thus affects the other IDs.
+ OM.index(V);
+}
+
+static OrderMap orderModule(const Module &M) {
+ // This needs to match the order used by ValueEnumerator::ValueEnumerator()
+ // and ValueEnumerator::incorporateFunction().
+ OrderMap OM;
+
+ // In the reader, initializers of GlobalValues are set *after* all the
+ // globals have been read. Rather than awkwardly modeling this behaviour
+ // directly in predictValueUseListOrderImpl(), just assign IDs to
+ // initializers of GlobalValues before GlobalValues themselves to model this
+ // implicitly.
+ for (const GlobalVariable &G : M.globals())
+ if (G.hasInitializer())
+ if (!isa<GlobalValue>(G.getInitializer()))
+ orderValue(G.getInitializer(), OM);
+ for (const GlobalAlias &A : M.aliases())
+ if (!isa<GlobalValue>(A.getAliasee()))
+ orderValue(A.getAliasee(), OM);
+ for (const GlobalIFunc &I : M.ifuncs())
+ if (!isa<GlobalValue>(I.getResolver()))
+ orderValue(I.getResolver(), OM);
+ for (const Function &F : M) {
+ for (const Use &U : F.operands())
+ if (!isa<GlobalValue>(U.get()))
+ orderValue(U.get(), OM);
+ }
+ OM.LastGlobalConstantID = OM.size();
+
+ // Initializers of GlobalValues are processed in
+ // BitcodeReader::ResolveGlobalAndAliasInits(). Match the order there rather
+ // than ValueEnumerator, and match the code in predictValueUseListOrderImpl()
+ // by giving IDs in reverse order.
+ //
+ // Since GlobalValues never reference each other directly (just through
+ // initializers), their relative IDs only matter for determining order of
+ // uses in their initializers.
+ for (const Function &F : M)
+ orderValue(&F, OM);
+ for (const GlobalAlias &A : M.aliases())
+ orderValue(&A, OM);
+ for (const GlobalIFunc &I : M.ifuncs())
+ orderValue(&I, OM);
+ for (const GlobalVariable &G : M.globals())
+ orderValue(&G, OM);
+ OM.LastGlobalValueID = OM.size();
+
+ for (const Function &F : M) {
+ if (F.isDeclaration())
+ continue;
+ // Here we need to match the union of ValueEnumerator::incorporateFunction()
+ // and WriteFunction(). Basic blocks are implicitly declared before
+ // anything else (by declaring their size).
+ for (const BasicBlock &BB : F)
+ orderValue(&BB, OM);
+ for (const Argument &A : F.args())
+ orderValue(&A, OM);
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ for (const Value *Op : I.operands())
+ if ((isa<Constant>(*Op) && !isa<GlobalValue>(*Op)) ||
+ isa<InlineAsm>(*Op))
+ orderValue(Op, OM);
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ orderValue(&I, OM);
+ }
+ return OM;
+}
+
+static void predictValueUseListOrderImpl(const Value *V, const Function *F,
+ unsigned ID, const OrderMap &OM,
+ UseListOrderStack &Stack) {
+ // Predict use-list order for this one.
+ using Entry = std::pair<const Use *, unsigned>;
+ SmallVector<Entry, 64> List;
+ for (const Use &U : V->uses())
+ // Check if this user will be serialized.
+ if (OM.lookup(U.getUser()).first)
+ List.push_back(std::make_pair(&U, List.size()));
+
+ if (List.size() < 2)
+ // We may have lost some users.
+ return;
+
+ bool IsGlobalValue = OM.isGlobalValue(ID);
+ llvm::sort(List, [&](const Entry &L, const Entry &R) {
+ const Use *LU = L.first;
+ const Use *RU = R.first;
+ if (LU == RU)
+ return false;
+
+ auto LID = OM.lookup(LU->getUser()).first;
+ auto RID = OM.lookup(RU->getUser()).first;
+
+ // Global values are processed in reverse order.
+ //
+ // Moreover, initializers of GlobalValues are set *after* all the globals
+ // have been read (despite having earlier IDs). Rather than awkwardly
+ // modeling this behaviour here, orderModule() has assigned IDs to
+ // initializers of GlobalValues before GlobalValues themselves.
+ if (OM.isGlobalValue(LID) && OM.isGlobalValue(RID))
+ return LID < RID;
+
+ // If ID is 4, then expect: 7 6 5 1 2 3.
+ if (LID < RID) {
+ if (RID <= ID)
+ if (!IsGlobalValue) // GlobalValue uses don't get reversed.
+ return true;
+ return false;
+ }
+ if (RID < LID) {
+ if (LID <= ID)
+ if (!IsGlobalValue) // GlobalValue uses don't get reversed.
+ return false;
+ return true;
+ }
+
+ // LID and RID are equal, so we have different operands of the same user.
+ // Assume operands are added in order for all instructions.
+ if (LID <= ID)
+ if (!IsGlobalValue) // GlobalValue uses don't get reversed.
+ return LU->getOperandNo() < RU->getOperandNo();
+ return LU->getOperandNo() > RU->getOperandNo();
+ });
+
+ if (std::is_sorted(
+ List.begin(), List.end(),
+ [](const Entry &L, const Entry &R) { return L.second < R.second; }))
+ // Order is already correct.
+ return;
+
+ // Store the shuffle.
+ Stack.emplace_back(V, F, List.size());
+ assert(List.size() == Stack.back().Shuffle.size() && "Wrong size");
+ for (size_t I = 0, E = List.size(); I != E; ++I)
+ Stack.back().Shuffle[I] = List[I].second;
+}
+
+static void predictValueUseListOrder(const Value *V, const Function *F,
+ OrderMap &OM, UseListOrderStack &Stack) {
+ auto &IDPair = OM[V];
+ assert(IDPair.first && "Unmapped value");
+ if (IDPair.second)
+ // Already predicted.
+ return;
+
+ // Do the actual prediction.
+ IDPair.second = true;
+ if (!V->use_empty() && std::next(V->use_begin()) != V->use_end())
+ predictValueUseListOrderImpl(V, F, IDPair.first, OM, Stack);
+
+ // Recursive descent into constants.
+ if (const Constant *C = dyn_cast<Constant>(V))
+ if (C->getNumOperands()) // Visit GlobalValues.
+ for (const Value *Op : C->operands())
+ if (isa<Constant>(Op)) // Visit GlobalValues.
+ predictValueUseListOrder(Op, F, OM, Stack);
+}
+
+static UseListOrderStack predictUseListOrder(const Module &M) {
+ OrderMap OM = orderModule(M);
+
+ // Use-list orders need to be serialized after all the users have been added
+ // to a value, or else the shuffles will be incomplete. Store them per
+ // function in a stack.
+ //
+ // Aside from function order, the order of values doesn't matter much here.
+ UseListOrderStack Stack;
+
+ // We want to visit the functions backward now so we can list function-local
+ // constants in the last Function they're used in. Module-level constants
+ // have already been visited above.
+ for (auto I = M.rbegin(), E = M.rend(); I != E; ++I) {
+ const Function &F = *I;
+ if (F.isDeclaration())
+ continue;
+ for (const BasicBlock &BB : F)
+ predictValueUseListOrder(&BB, &F, OM, Stack);
+ for (const Argument &A : F.args())
+ predictValueUseListOrder(&A, &F, OM, Stack);
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ for (const Value *Op : I.operands())
+ if (isa<Constant>(*Op) || isa<InlineAsm>(*Op)) // Visit GlobalValues.
+ predictValueUseListOrder(Op, &F, OM, Stack);
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ predictValueUseListOrder(&I, &F, OM, Stack);
+ }
+
+ // Visit globals last, since the module-level use-list block will be seen
+ // before the function bodies are processed.
+ for (const GlobalVariable &G : M.globals())
+ predictValueUseListOrder(&G, nullptr, OM, Stack);
+ for (const Function &F : M)
+ predictValueUseListOrder(&F, nullptr, OM, Stack);
+ for (const GlobalAlias &A : M.aliases())
+ predictValueUseListOrder(&A, nullptr, OM, Stack);
+ for (const GlobalIFunc &I : M.ifuncs())
+ predictValueUseListOrder(&I, nullptr, OM, Stack);
+ for (const GlobalVariable &G : M.globals())
+ if (G.hasInitializer())
+ predictValueUseListOrder(G.getInitializer(), nullptr, OM, Stack);
+ for (const GlobalAlias &A : M.aliases())
+ predictValueUseListOrder(A.getAliasee(), nullptr, OM, Stack);
+ for (const GlobalIFunc &I : M.ifuncs())
+ predictValueUseListOrder(I.getResolver(), nullptr, OM, Stack);
+ for (const Function &F : M) {
+ for (const Use &U : F.operands())
+ predictValueUseListOrder(U.get(), nullptr, OM, Stack);
+ }
+
+ return Stack;
+}
+
+static bool isIntOrIntVectorValue(const std::pair<const Value*, unsigned> &V) {
+ return V.first->getType()->isIntOrIntVectorTy();
+}
+
+ValueEnumerator::ValueEnumerator(const Module &M,
+ bool ShouldPreserveUseListOrder)
+ : ShouldPreserveUseListOrder(ShouldPreserveUseListOrder) {
+ if (ShouldPreserveUseListOrder)
+ UseListOrders = predictUseListOrder(M);
+
+ // Enumerate the global variables.
+ for (const GlobalVariable &GV : M.globals())
+ EnumerateValue(&GV);
+
+ // Enumerate the functions.
+ for (const Function & F : M) {
+ EnumerateValue(&F);
+ EnumerateAttributes(F.getAttributes());
+ }
+
+ // Enumerate the aliases.
+ for (const GlobalAlias &GA : M.aliases())
+ EnumerateValue(&GA);
+
+ // Enumerate the ifuncs.
+ for (const GlobalIFunc &GIF : M.ifuncs())
+ EnumerateValue(&GIF);
+
+ // Remember what is the cutoff between globalvalue's and other constants.
+ unsigned FirstConstant = Values.size();
+
+ // Enumerate the global variable initializers and attributes.
+ for (const GlobalVariable &GV : M.globals()) {
+ if (GV.hasInitializer())
+ EnumerateValue(GV.getInitializer());
+ if (GV.hasAttributes())
+ EnumerateAttributes(GV.getAttributesAsList(AttributeList::FunctionIndex));
+ }
+
+ // Enumerate the aliasees.
+ for (const GlobalAlias &GA : M.aliases())
+ EnumerateValue(GA.getAliasee());
+
+ // Enumerate the ifunc resolvers.
+ for (const GlobalIFunc &GIF : M.ifuncs())
+ EnumerateValue(GIF.getResolver());
+
+ // Enumerate any optional Function data.
+ for (const Function &F : M)
+ for (const Use &U : F.operands())
+ EnumerateValue(U.get());
+
+ // Enumerate the metadata type.
+ //
+ // TODO: Move this to ValueEnumerator::EnumerateOperandType() once bitcode
+ // only encodes the metadata type when it's used as a value.
+ EnumerateType(Type::getMetadataTy(M.getContext()));
+
+ // Insert constants and metadata that are named at module level into the slot
+ // pool so that the module symbol table can refer to them...
+ EnumerateValueSymbolTable(M.getValueSymbolTable());
+ EnumerateNamedMetadata(M);
+
+ SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
+ for (const GlobalVariable &GV : M.globals()) {
+ MDs.clear();
+ GV.getAllMetadata(MDs);
+ for (const auto &I : MDs)
+ // FIXME: Pass GV to EnumerateMetadata and arrange for the bitcode writer
+ // to write metadata to the global variable's own metadata block
+ // (PR28134).
+ EnumerateMetadata(nullptr, I.second);
+ }
+
+ // Enumerate types used by function bodies and argument lists.
+ for (const Function &F : M) {
+ for (const Argument &A : F.args())
+ EnumerateType(A.getType());
+
+ // Enumerate metadata attached to this function.
+ MDs.clear();
+ F.getAllMetadata(MDs);
+ for (const auto &I : MDs)
+ EnumerateMetadata(F.isDeclaration() ? nullptr : &F, I.second);
+
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB) {
+ for (const Use &Op : I.operands()) {
+ auto *MD = dyn_cast<MetadataAsValue>(&Op);
+ if (!MD) {
+ EnumerateOperandType(Op);
+ continue;
+ }
+
+ // Local metadata is enumerated during function-incorporation.
+ if (isa<LocalAsMetadata>(MD->getMetadata()))
+ continue;
+
+ EnumerateMetadata(&F, MD->getMetadata());
+ }
+ EnumerateType(I.getType());
+ if (const auto *Call = dyn_cast<CallBase>(&I))
+ EnumerateAttributes(Call->getAttributes());
+
+ // Enumerate metadata attached with this instruction.
+ MDs.clear();
+ I.getAllMetadataOtherThanDebugLoc(MDs);
+ for (unsigned i = 0, e = MDs.size(); i != e; ++i)
+ EnumerateMetadata(&F, MDs[i].second);
+
+ // Don't enumerate the location directly -- it has a special record
+ // type -- but enumerate its operands.
+ if (DILocation *L = I.getDebugLoc())
+ for (const Metadata *Op : L->operands())
+ EnumerateMetadata(&F, Op);
+ }
+ }
+
+ // Optimize constant ordering.
+ OptimizeConstants(FirstConstant, Values.size());
+
+ // Organize metadata ordering.
+ organizeMetadata();
+}
+
+unsigned ValueEnumerator::getInstructionID(const Instruction *Inst) const {
+ InstructionMapType::const_iterator I = InstructionMap.find(Inst);
+ assert(I != InstructionMap.end() && "Instruction is not mapped!");
+ return I->second;
+}
+
+unsigned ValueEnumerator::getComdatID(const Comdat *C) const {
+ unsigned ComdatID = Comdats.idFor(C);
+ assert(ComdatID && "Comdat not found!");
+ return ComdatID;
+}
+
+void ValueEnumerator::setInstructionID(const Instruction *I) {
+ InstructionMap[I] = InstructionCount++;
+}
+
+unsigned ValueEnumerator::getValueID(const Value *V) const {
+ if (auto *MD = dyn_cast<MetadataAsValue>(V))
+ return getMetadataID(MD->getMetadata());
+
+ ValueMapType::const_iterator I = ValueMap.find(V);
+ assert(I != ValueMap.end() && "Value not in slotcalculator!");
+ return I->second-1;
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+LLVM_DUMP_METHOD void ValueEnumerator::dump() const {
+ print(dbgs(), ValueMap, "Default");
+ dbgs() << '\n';
+ print(dbgs(), MetadataMap, "MetaData");
+ dbgs() << '\n';
+}
+#endif
+
+void ValueEnumerator::print(raw_ostream &OS, const ValueMapType &Map,
+ const char *Name) const {
+ OS << "Map Name: " << Name << "\n";
+ OS << "Size: " << Map.size() << "\n";
+ for (ValueMapType::const_iterator I = Map.begin(),
+ E = Map.end(); I != E; ++I) {
+ const Value *V = I->first;
+ if (V->hasName())
+ OS << "Value: " << V->getName();
+ else
+ OS << "Value: [null]\n";
+ V->print(errs());
+ errs() << '\n';
+
+ OS << " Uses(" << V->getNumUses() << "):";
+ for (const Use &U : V->uses()) {
+ if (&U != &*V->use_begin())
+ OS << ",";
+ if(U->hasName())
+ OS << " " << U->getName();
+ else
+ OS << " [null]";
+
+ }
+ OS << "\n\n";
+ }
+}
+
+void ValueEnumerator::print(raw_ostream &OS, const MetadataMapType &Map,
+ const char *Name) const {
+ OS << "Map Name: " << Name << "\n";
+ OS << "Size: " << Map.size() << "\n";
+ for (auto I = Map.begin(), E = Map.end(); I != E; ++I) {
+ const Metadata *MD = I->first;
+ OS << "Metadata: slot = " << I->second.ID << "\n";
+ OS << "Metadata: function = " << I->second.F << "\n";
+ MD->print(OS);
+ OS << "\n";
+ }
+}
+
+/// OptimizeConstants - Reorder constant pool for denser encoding.
+void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
+ if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
+
+ if (ShouldPreserveUseListOrder)
+ // Optimizing constants makes the use-list order difficult to predict.
+ // Disable it for now when trying to preserve the order.
+ return;
+
+ std::stable_sort(Values.begin() + CstStart, Values.begin() + CstEnd,
+ [this](const std::pair<const Value *, unsigned> &LHS,
+ const std::pair<const Value *, unsigned> &RHS) {
+ // Sort by plane.
+ if (LHS.first->getType() != RHS.first->getType())
+ return getTypeID(LHS.first->getType()) < getTypeID(RHS.first->getType());
+ // Then by frequency.
+ return LHS.second > RHS.second;
+ });
+
+ // Ensure that integer and vector of integer constants are at the start of the
+ // constant pool. This is important so that GEP structure indices come before
+ // gep constant exprs.
+ std::stable_partition(Values.begin() + CstStart, Values.begin() + CstEnd,
+ isIntOrIntVectorValue);
+
+ // Rebuild the modified portion of ValueMap.
+ for (; CstStart != CstEnd; ++CstStart)
+ ValueMap[Values[CstStart].first] = CstStart+1;
+}
+
+/// EnumerateValueSymbolTable - Insert all of the values in the specified symbol
+/// table into the values table.
+void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
+ for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end();
+ VI != VE; ++VI)
+ EnumerateValue(VI->getValue());
+}
+
+/// Insert all of the values referenced by named metadata in the specified
+/// module.
+void ValueEnumerator::EnumerateNamedMetadata(const Module &M) {
+ for (const auto &I : M.named_metadata())
+ EnumerateNamedMDNode(&I);
+}
+
+void ValueEnumerator::EnumerateNamedMDNode(const NamedMDNode *MD) {
+ for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i)
+ EnumerateMetadata(nullptr, MD->getOperand(i));
+}
+
+unsigned ValueEnumerator::getMetadataFunctionID(const Function *F) const {
+ return F ? getValueID(F) + 1 : 0;
+}
+
+void ValueEnumerator::EnumerateMetadata(const Function *F, const Metadata *MD) {
+ EnumerateMetadata(getMetadataFunctionID(F), MD);
+}
+
+void ValueEnumerator::EnumerateFunctionLocalMetadata(
+ const Function &F, const LocalAsMetadata *Local) {
+ EnumerateFunctionLocalMetadata(getMetadataFunctionID(&F), Local);
+}
+
+void ValueEnumerator::dropFunctionFromMetadata(
+ MetadataMapType::value_type &FirstMD) {
+ SmallVector<const MDNode *, 64> Worklist;
+ auto push = [&Worklist](MetadataMapType::value_type &MD) {
+ auto &Entry = MD.second;
+
+ // Nothing to do if this metadata isn't tagged.
+ if (!Entry.F)
+ return;
+
+ // Drop the function tag.
+ Entry.F = 0;
+
+ // If this is has an ID and is an MDNode, then its operands have entries as
+ // well. We need to drop the function from them too.
+ if (Entry.ID)
+ if (auto *N = dyn_cast<MDNode>(MD.first))
+ Worklist.push_back(N);
+ };
+ push(FirstMD);
+ while (!Worklist.empty())
+ for (const Metadata *Op : Worklist.pop_back_val()->operands()) {
+ if (!Op)
+ continue;
+ auto MD = MetadataMap.find(Op);
+ if (MD != MetadataMap.end())
+ push(*MD);
+ }
+}
+
+void ValueEnumerator::EnumerateMetadata(unsigned F, const Metadata *MD) {
+ // It's vital for reader efficiency that uniqued subgraphs are done in
+ // post-order; it's expensive when their operands have forward references.
+ // If a distinct node is referenced from a uniqued node, it'll be delayed
+ // until the uniqued subgraph has been completely traversed.
+ SmallVector<const MDNode *, 32> DelayedDistinctNodes;
+
+ // Start by enumerating MD, and then work through its transitive operands in
+ // post-order. This requires a depth-first search.
+ SmallVector<std::pair<const MDNode *, MDNode::op_iterator>, 32> Worklist;
+ if (const MDNode *N = enumerateMetadataImpl(F, MD))
+ Worklist.push_back(std::make_pair(N, N->op_begin()));
+
+ while (!Worklist.empty()) {
+ const MDNode *N = Worklist.back().first;
+
+ // Enumerate operands until we hit a new node. We need to traverse these
+ // nodes' operands before visiting the rest of N's operands.
+ MDNode::op_iterator I = std::find_if(
+ Worklist.back().second, N->op_end(),
+ [&](const Metadata *MD) { return enumerateMetadataImpl(F, MD); });
+ if (I != N->op_end()) {
+ auto *Op = cast<MDNode>(*I);
+ Worklist.back().second = ++I;
+
+ // Delay traversing Op if it's a distinct node and N is uniqued.
+ if (Op->isDistinct() && !N->isDistinct())
+ DelayedDistinctNodes.push_back(Op);
+ else
+ Worklist.push_back(std::make_pair(Op, Op->op_begin()));
+ continue;
+ }
+
+ // All the operands have been visited. Now assign an ID.
+ Worklist.pop_back();
+ MDs.push_back(N);
+ MetadataMap[N].ID = MDs.size();
+
+ // Flush out any delayed distinct nodes; these are all the distinct nodes
+ // that are leaves in last uniqued subgraph.
+ if (Worklist.empty() || Worklist.back().first->isDistinct()) {
+ for (const MDNode *N : DelayedDistinctNodes)
+ Worklist.push_back(std::make_pair(N, N->op_begin()));
+ DelayedDistinctNodes.clear();
+ }
+ }
+}
+
+const MDNode *ValueEnumerator::enumerateMetadataImpl(unsigned F, const Metadata *MD) {
+ if (!MD)
+ return nullptr;
+
+ assert(
+ (isa<MDNode>(MD) || isa<MDString>(MD) || isa<ConstantAsMetadata>(MD)) &&
+ "Invalid metadata kind");
+
+ auto Insertion = MetadataMap.insert(std::make_pair(MD, MDIndex(F)));
+ MDIndex &Entry = Insertion.first->second;
+ if (!Insertion.second) {
+ // Already mapped. If F doesn't match the function tag, drop it.
+ if (Entry.hasDifferentFunction(F))
+ dropFunctionFromMetadata(*Insertion.first);
+ return nullptr;
+ }
+
+ // Don't assign IDs to metadata nodes.
+ if (auto *N = dyn_cast<MDNode>(MD))
+ return N;
+
+ // Save the metadata.
+ MDs.push_back(MD);
+ Entry.ID = MDs.size();
+
+ // Enumerate the constant, if any.
+ if (auto *C = dyn_cast<ConstantAsMetadata>(MD))
+ EnumerateValue(C->getValue());
+
+ return nullptr;
+}
+
+/// EnumerateFunctionLocalMetadataa - Incorporate function-local metadata
+/// information reachable from the metadata.
+void ValueEnumerator::EnumerateFunctionLocalMetadata(
+ unsigned F, const LocalAsMetadata *Local) {
+ assert(F && "Expected a function");
+
+ // Check to see if it's already in!
+ MDIndex &Index = MetadataMap[Local];
+ if (Index.ID) {
+ assert(Index.F == F && "Expected the same function");
+ return;
+ }
+
+ MDs.push_back(Local);
+ Index.F = F;
+ Index.ID = MDs.size();
+
+ EnumerateValue(Local->getValue());
+}
+
+static unsigned getMetadataTypeOrder(const Metadata *MD) {
+ // Strings are emitted in bulk and must come first.
+ if (isa<MDString>(MD))
+ return 0;
+
+ // ConstantAsMetadata doesn't reference anything. We may as well shuffle it
+ // to the front since we can detect it.
+ auto *N = dyn_cast<MDNode>(MD);
+ if (!N)
+ return 1;
+
+ // The reader is fast forward references for distinct node operands, but slow
+ // when uniqued operands are unresolved.
+ return N->isDistinct() ? 2 : 3;
+}
+
+void ValueEnumerator::organizeMetadata() {
+ assert(MetadataMap.size() == MDs.size() &&
+ "Metadata map and vector out of sync");
+
+ if (MDs.empty())
+ return;
+
+ // Copy out the index information from MetadataMap in order to choose a new
+ // order.
+ SmallVector<MDIndex, 64> Order;
+ Order.reserve(MetadataMap.size());
+ for (const Metadata *MD : MDs)
+ Order.push_back(MetadataMap.lookup(MD));
+
+ // Partition:
+ // - by function, then
+ // - by isa<MDString>
+ // and then sort by the original/current ID. Since the IDs are guaranteed to
+ // be unique, the result of std::sort will be deterministic. There's no need
+ // for std::stable_sort.
+ llvm::sort(Order, [this](MDIndex LHS, MDIndex RHS) {
+ return std::make_tuple(LHS.F, getMetadataTypeOrder(LHS.get(MDs)), LHS.ID) <
+ std::make_tuple(RHS.F, getMetadataTypeOrder(RHS.get(MDs)), RHS.ID);
+ });
+
+ // Rebuild MDs, index the metadata ranges for each function in FunctionMDs,
+ // and fix up MetadataMap.
+ std::vector<const Metadata *> OldMDs;
+ MDs.swap(OldMDs);
+ MDs.reserve(OldMDs.size());
+ for (unsigned I = 0, E = Order.size(); I != E && !Order[I].F; ++I) {
+ auto *MD = Order[I].get(OldMDs);
+ MDs.push_back(MD);
+ MetadataMap[MD].ID = I + 1;
+ if (isa<MDString>(MD))
+ ++NumMDStrings;
+ }
+
+ // Return early if there's nothing for the functions.
+ if (MDs.size() == Order.size())
+ return;
+
+ // Build the function metadata ranges.
+ MDRange R;
+ FunctionMDs.reserve(OldMDs.size());
+ unsigned PrevF = 0;
+ for (unsigned I = MDs.size(), E = Order.size(), ID = MDs.size(); I != E;
+ ++I) {
+ unsigned F = Order[I].F;
+ if (!PrevF) {
+ PrevF = F;
+ } else if (PrevF != F) {
+ R.Last = FunctionMDs.size();
+ std::swap(R, FunctionMDInfo[PrevF]);
+ R.First = FunctionMDs.size();
+
+ ID = MDs.size();
+ PrevF = F;
+ }
+
+ auto *MD = Order[I].get(OldMDs);
+ FunctionMDs.push_back(MD);
+ MetadataMap[MD].ID = ++ID;
+ if (isa<MDString>(MD))
+ ++R.NumStrings;
+ }
+ R.Last = FunctionMDs.size();
+ FunctionMDInfo[PrevF] = R;
+}
+
+void ValueEnumerator::incorporateFunctionMetadata(const Function &F) {
+ NumModuleMDs = MDs.size();
+
+ auto R = FunctionMDInfo.lookup(getValueID(&F) + 1);
+ NumMDStrings = R.NumStrings;
+ MDs.insert(MDs.end(), FunctionMDs.begin() + R.First,
+ FunctionMDs.begin() + R.Last);
+}
+
+void ValueEnumerator::EnumerateValue(const Value *V) {
+ assert(!V->getType()->isVoidTy() && "Can't insert void values!");
+ assert(!isa<MetadataAsValue>(V) && "EnumerateValue doesn't handle Metadata!");
+
+ // Check to see if it's already in!
+ unsigned &ValueID = ValueMap[V];
+ if (ValueID) {
+ // Increment use count.
+ Values[ValueID-1].second++;
+ return;
+ }
+
+ if (auto *GO = dyn_cast<GlobalObject>(V))
+ if (const Comdat *C = GO->getComdat())
+ Comdats.insert(C);
+
+ // Enumerate the type of this value.
+ EnumerateType(V->getType());
+
+ if (const Constant *C = dyn_cast<Constant>(V)) {
+ if (isa<GlobalValue>(C)) {
+ // Initializers for globals are handled explicitly elsewhere.
+ } else if (C->getNumOperands()) {
+ // If a constant has operands, enumerate them. This makes sure that if a
+ // constant has uses (for example an array of const ints), that they are
+ // inserted also.
+
+ // We prefer to enumerate them with values before we enumerate the user
+ // itself. This makes it more likely that we can avoid forward references
+ // in the reader. We know that there can be no cycles in the constants
+ // graph that don't go through a global variable.
+ for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
+ I != E; ++I)
+ if (!isa<BasicBlock>(*I)) // Don't enumerate BB operand to BlockAddress.
+ EnumerateValue(*I);
+
+ // Finally, add the value. Doing this could make the ValueID reference be
+ // dangling, don't reuse it.
+ Values.push_back(std::make_pair(V, 1U));
+ ValueMap[V] = Values.size();
+ return;
+ }
+ }
+
+ // Add the value.
+ Values.push_back(std::make_pair(V, 1U));
+ ValueID = Values.size();
+}
+
+
+void ValueEnumerator::EnumerateType(Type *Ty) {
+ unsigned *TypeID = &TypeMap[Ty];
+
+ // We've already seen this type.
+ if (*TypeID)
+ return;
+
+ // If it is a non-anonymous struct, mark the type as being visited so that we
+ // don't recursively visit it. This is safe because we allow forward
+ // references of these in the bitcode reader.
+ if (StructType *STy = dyn_cast<StructType>(Ty))
+ if (!STy->isLiteral())
+ *TypeID = ~0U;
+
+ // Enumerate all of the subtypes before we enumerate this type. This ensures
+ // that the type will be enumerated in an order that can be directly built.
+ for (Type *SubTy : Ty->subtypes())
+ EnumerateType(SubTy);
+
+ // Refresh the TypeID pointer in case the table rehashed.
+ TypeID = &TypeMap[Ty];
+
+ // Check to see if we got the pointer another way. This can happen when
+ // enumerating recursive types that hit the base case deeper than they start.
+ //
+ // If this is actually a struct that we are treating as forward ref'able,
+ // then emit the definition now that all of its contents are available.
+ if (*TypeID && *TypeID != ~0U)
+ return;
+
+ // Add this type now that its contents are all happily enumerated.
+ Types.push_back(Ty);
+
+ *TypeID = Types.size();
+}
+
+// Enumerate the types for the specified value. If the value is a constant,
+// walk through it, enumerating the types of the constant.
+void ValueEnumerator::EnumerateOperandType(const Value *V) {
+ EnumerateType(V->getType());
+
+ assert(!isa<MetadataAsValue>(V) && "Unexpected metadata operand");
+
+ const Constant *C = dyn_cast<Constant>(V);
+ if (!C)
+ return;
+
+ // If this constant is already enumerated, ignore it, we know its type must
+ // be enumerated.
+ if (ValueMap.count(C))
+ return;
+
+ // This constant may have operands, make sure to enumerate the types in
+ // them.
+ for (const Value *Op : C->operands()) {
+ // Don't enumerate basic blocks here, this happens as operands to
+ // blockaddress.
+ if (isa<BasicBlock>(Op))
+ continue;
+
+ EnumerateOperandType(Op);
+ }
+}
+
+void ValueEnumerator::EnumerateAttributes(AttributeList PAL) {
+ if (PAL.isEmpty()) return; // null is always 0.
+
+ // Do a lookup.
+ unsigned &Entry = AttributeListMap[PAL];
+ if (Entry == 0) {
+ // Never saw this before, add it.
+ AttributeLists.push_back(PAL);
+ Entry = AttributeLists.size();
+ }
+
+ // Do lookups for all attribute groups.
+ for (unsigned i = PAL.index_begin(), e = PAL.index_end(); i != e; ++i) {
+ AttributeSet AS = PAL.getAttributes(i);
+ if (!AS.hasAttributes())
+ continue;
+ IndexAndAttrSet Pair = {i, AS};
+ unsigned &Entry = AttributeGroupMap[Pair];
+ if (Entry == 0) {
+ AttributeGroups.push_back(Pair);
+ Entry = AttributeGroups.size();
+ }
+ }
+}
+
+void ValueEnumerator::incorporateFunction(const Function &F) {
+ InstructionCount = 0;
+ NumModuleValues = Values.size();
+
+ // Add global metadata to the function block. This doesn't include
+ // LocalAsMetadata.
+ incorporateFunctionMetadata(F);
+
+ // Adding function arguments to the value table.
+ for (const auto &I : F.args()) {
+ EnumerateValue(&I);
+ if (I.hasAttribute(Attribute::ByVal))
+ EnumerateType(I.getParamByValType());
+ }
+ FirstFuncConstantID = Values.size();
+
+ // Add all function-level constants to the value table.
+ for (const BasicBlock &BB : F) {
+ for (const Instruction &I : BB)
+ for (const Use &OI : I.operands()) {
+ if ((isa<Constant>(OI) && !isa<GlobalValue>(OI)) || isa<InlineAsm>(OI))
+ EnumerateValue(OI);
+ }
+ BasicBlocks.push_back(&BB);
+ ValueMap[&BB] = BasicBlocks.size();
+ }
+
+ // Optimize the constant layout.
+ OptimizeConstants(FirstFuncConstantID, Values.size());
+
+ // Add the function's parameter attributes so they are available for use in
+ // the function's instruction.
+ EnumerateAttributes(F.getAttributes());
+
+ FirstInstID = Values.size();
+
+ SmallVector<LocalAsMetadata *, 8> FnLocalMDVector;
+ // Add all of the instructions.
+ for (const BasicBlock &BB : F) {
+ for (const Instruction &I : BB) {
+ for (const Use &OI : I.operands()) {
+ if (auto *MD = dyn_cast<MetadataAsValue>(&OI))
+ if (auto *Local = dyn_cast<LocalAsMetadata>(MD->getMetadata()))
+ // Enumerate metadata after the instructions they might refer to.
+ FnLocalMDVector.push_back(Local);
+ }
+
+ if (!I.getType()->isVoidTy())
+ EnumerateValue(&I);
+ }
+ }
+
+ // Add all of the function-local metadata.
+ for (unsigned i = 0, e = FnLocalMDVector.size(); i != e; ++i) {
+ // At this point, every local values have been incorporated, we shouldn't
+ // have a metadata operand that references a value that hasn't been seen.
+ assert(ValueMap.count(FnLocalMDVector[i]->getValue()) &&
+ "Missing value for metadata operand");
+ EnumerateFunctionLocalMetadata(F, FnLocalMDVector[i]);
+ }
+}
+
+void ValueEnumerator::purgeFunction() {
+ /// Remove purged values from the ValueMap.
+ for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i)
+ ValueMap.erase(Values[i].first);
+ for (unsigned i = NumModuleMDs, e = MDs.size(); i != e; ++i)
+ MetadataMap.erase(MDs[i]);
+ for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
+ ValueMap.erase(BasicBlocks[i]);
+
+ Values.resize(NumModuleValues);
+ MDs.resize(NumModuleMDs);
+ BasicBlocks.clear();
+ NumMDStrings = 0;
+}
+
+static void IncorporateFunctionInfoGlobalBBIDs(const Function *F,
+ DenseMap<const BasicBlock*, unsigned> &IDMap) {
+ unsigned Counter = 0;
+ for (const BasicBlock &BB : *F)
+ IDMap[&BB] = ++Counter;
+}
+
+/// getGlobalBasicBlockID - This returns the function-specific ID for the
+/// specified basic block. This is relatively expensive information, so it
+/// should only be used by rare constructs such as address-of-label.
+unsigned ValueEnumerator::getGlobalBasicBlockID(const BasicBlock *BB) const {
+ unsigned &Idx = GlobalBasicBlockIDs[BB];
+ if (Idx != 0)
+ return Idx-1;
+
+ IncorporateFunctionInfoGlobalBBIDs(BB->getParent(), GlobalBasicBlockIDs);
+ return getGlobalBasicBlockID(BB);
+}
+
+uint64_t ValueEnumerator::computeBitsRequiredForTypeIndicies() const {
+ return Log2_32_Ceil(getTypes().size() + 1);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-13 15:46:06 +0000