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//===-- TypesContext.h - Types-related Context Internals ------------------===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file defines various helper methods and classes used by
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// LLVMContextImpl for creating and managing types.
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_TYPESCONTEXT_H
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#define LLVM_TYPESCONTEXT_H
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#include "llvm/ADT/STLExtras.h"
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//===----------------------------------------------------------------------===//
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// Derived Type Factory Functions
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//===----------------------------------------------------------------------===//
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/// getSubElementHash - Generate a hash value for all of the SubType's of this
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/// type. The hash value is guaranteed to be zero if any of the subtypes are
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/// an opaque type. Otherwise we try to mix them in as well as possible, but do
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/// not look at the subtype's subtype's.
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static unsigned getSubElementHash(const Type *Ty) {
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for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
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const Type *SubTy = I->get();
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HashVal += SubTy->getTypeID();
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switch (SubTy->getTypeID()) {
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case Type::OpaqueTyID: return 0; // Opaque -> hash = 0 no matter what.
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case Type::IntegerTyID:
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HashVal ^= (cast<IntegerType>(SubTy)->getBitWidth() << 3);
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case Type::FunctionTyID:
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HashVal ^= cast<FunctionType>(SubTy)->getNumParams()*2 +
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cast<FunctionType>(SubTy)->isVarArg();
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HashVal ^= cast<ArrayType>(SubTy)->getNumElements();
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case Type::VectorTyID:
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HashVal ^= cast<VectorType>(SubTy)->getNumElements();
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case Type::StructTyID:
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HashVal ^= cast<StructType>(SubTy)->getNumElements();
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case Type::PointerTyID:
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HashVal ^= cast<PointerType>(SubTy)->getAddressSpace();
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return HashVal ? HashVal : 1; // Do not return zero unless opaque subty.
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//===----------------------------------------------------------------------===//
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// Integer Type Factory...
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class IntegerValType {
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IntegerValType(uint32_t numbits) : bits(numbits) {}
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static IntegerValType get(const IntegerType *Ty) {
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return IntegerValType(Ty->getBitWidth());
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static unsigned hashTypeStructure(const IntegerType *Ty) {
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return (unsigned)Ty->getBitWidth();
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inline bool operator<(const IntegerValType &IVT) const {
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return bits < IVT.bits;
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// PointerValType - Define a class to hold the key that goes into the TypeMap
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class PointerValType {
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unsigned AddressSpace;
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PointerValType(const Type *val, unsigned as) : ValTy(val), AddressSpace(as) {}
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static PointerValType get(const PointerType *PT) {
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return PointerValType(PT->getElementType(), PT->getAddressSpace());
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static unsigned hashTypeStructure(const PointerType *PT) {
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return getSubElementHash(PT);
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bool operator<(const PointerValType &MTV) const {
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if (AddressSpace < MTV.AddressSpace) return true;
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return AddressSpace == MTV.AddressSpace && ValTy < MTV.ValTy;
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//===----------------------------------------------------------------------===//
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// Array Type Factory...
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ArrayValType(const Type *val, uint64_t sz) : ValTy(val), Size(sz) {}
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static ArrayValType get(const ArrayType *AT) {
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return ArrayValType(AT->getElementType(), AT->getNumElements());
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static unsigned hashTypeStructure(const ArrayType *AT) {
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return (unsigned)AT->getNumElements();
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inline bool operator<(const ArrayValType &MTV) const {
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if (Size < MTV.Size) return true;
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return Size == MTV.Size && ValTy < MTV.ValTy;
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//===----------------------------------------------------------------------===//
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// Vector Type Factory...
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class VectorValType {
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VectorValType(const Type *val, int sz) : ValTy(val), Size(sz) {}
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static VectorValType get(const VectorType *PT) {
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return VectorValType(PT->getElementType(), PT->getNumElements());
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static unsigned hashTypeStructure(const VectorType *PT) {
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return PT->getNumElements();
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inline bool operator<(const VectorValType &MTV) const {
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if (Size < MTV.Size) return true;
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return Size == MTV.Size && ValTy < MTV.ValTy;
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// StructValType - Define a class to hold the key that goes into the TypeMap
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class StructValType {
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std::vector<const Type*> ElTypes;
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StructValType(const std::vector<const Type*> &args, bool isPacked)
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: ElTypes(args), packed(isPacked) {}
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static StructValType get(const StructType *ST) {
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std::vector<const Type *> ElTypes;
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ElTypes.reserve(ST->getNumElements());
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for (unsigned i = 0, e = ST->getNumElements(); i != e; ++i)
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ElTypes.push_back(ST->getElementType(i));
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return StructValType(ElTypes, ST->isPacked());
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static unsigned hashTypeStructure(const StructType *ST) {
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return ST->getNumElements();
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inline bool operator<(const StructValType &STV) const {
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if (ElTypes < STV.ElTypes) return true;
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else if (ElTypes > STV.ElTypes) return false;
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else return (int)packed < (int)STV.packed;
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// UnionValType - Define a class to hold the key that goes into the TypeMap
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std::vector<const Type*> ElTypes;
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UnionValType(const Type* const* Types, unsigned NumTypes)
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: ElTypes(&Types[0], &Types[NumTypes]) {}
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static UnionValType get(const UnionType *UT) {
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std::vector<const Type *> ElTypes;
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ElTypes.reserve(UT->getNumElements());
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for (unsigned i = 0, e = UT->getNumElements(); i != e; ++i)
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ElTypes.push_back(UT->getElementType(i));
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return UnionValType(&ElTypes[0], ElTypes.size());
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static unsigned hashTypeStructure(const UnionType *UT) {
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return UT->getNumElements();
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inline bool operator<(const UnionValType &UTV) const {
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return (ElTypes < UTV.ElTypes);
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// FunctionValType - Define a class to hold the key that goes into the TypeMap
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class FunctionValType {
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std::vector<const Type*> ArgTypes;
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FunctionValType(const Type *ret, const std::vector<const Type*> &args,
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bool isVA) : RetTy(ret), ArgTypes(args), isVarArg(isVA) {}
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static FunctionValType get(const FunctionType *FT);
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static unsigned hashTypeStructure(const FunctionType *FT) {
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unsigned Result = FT->getNumParams()*2 + FT->isVarArg();
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inline bool operator<(const FunctionValType &MTV) const {
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if (RetTy < MTV.RetTy) return true;
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if (RetTy > MTV.RetTy) return false;
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if (isVarArg < MTV.isVarArg) return true;
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if (isVarArg > MTV.isVarArg) return false;
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if (ArgTypes < MTV.ArgTypes) return true;
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if (ArgTypes > MTV.ArgTypes) return false;
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/// TypesByHash - Keep track of types by their structure hash value. Note
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/// that we only keep track of types that have cycles through themselves in
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std::multimap<unsigned, PATypeHolder> TypesByHash;
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// PATypeHolder won't destroy non-abstract types.
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// We can't destroy them by simply iterating, because
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// they may contain references to each-other.
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for (std::multimap<unsigned, PATypeHolder>::iterator I
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= TypesByHash.begin(), E = TypesByHash.end(); I != E; ++I) {
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Type *Ty = const_cast<Type*>(I->second.Ty);
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// We can't invoke destroy or delete, because the type may
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// contain references to already freed types.
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// So we have to destruct the object the ugly way.
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Ty->AbstractTypeUsers.clear();
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static_cast<const Type*>(Ty)->Type::~Type();
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void RemoveFromTypesByHash(unsigned Hash, const Type *Ty) {
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std::multimap<unsigned, PATypeHolder>::iterator I =
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TypesByHash.lower_bound(Hash);
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for (; I != TypesByHash.end() && I->first == Hash; ++I) {
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if (I->second == Ty) {
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TypesByHash.erase(I);
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// This must be do to an opaque type that was resolved. Switch down to hash
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assert(Hash && "Didn't find type entry!");
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RemoveFromTypesByHash(0, Ty);
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/// TypeBecameConcrete - When Ty gets a notification that TheType just became
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/// concrete, drop uses and make Ty non-abstract if we should.
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void TypeBecameConcrete(DerivedType *Ty, const DerivedType *TheType) {
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// If the element just became concrete, remove 'ty' from the abstract
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// type user list for the type. Do this for as many times as Ty uses
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for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
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if (I->get() == TheType)
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TheType->removeAbstractTypeUser(Ty);
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// If the type is currently thought to be abstract, rescan all of our
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// subtypes to see if the type has just become concrete! Note that this
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// may send out notifications to AbstractTypeUsers that types become
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if (Ty->isAbstract())
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Ty->PromoteAbstractToConcrete();
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// TypeMap - Make sure that only one instance of a particular type may be
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// created on any given run of the compiler... note that this involves updating
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// our map if an abstract type gets refined somehow.
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template<class ValType, class TypeClass>
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class TypeMap : public TypeMapBase {
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std::map<ValType, PATypeHolder> Map;
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typedef typename std::map<ValType, PATypeHolder>::iterator iterator;
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inline TypeClass *get(const ValType &V) {
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iterator I = Map.find(V);
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return I != Map.end() ? cast<TypeClass>((Type*)I->second.get()) : 0;
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inline void add(const ValType &V, TypeClass *Ty) {
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Map.insert(std::make_pair(V, Ty));
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// If this type has a cycle, remember it.
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TypesByHash.insert(std::make_pair(ValType::hashTypeStructure(Ty), Ty));
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/// RefineAbstractType - This method is called after we have merged a type
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/// with another one. We must now either merge the type away with
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/// some other type or reinstall it in the map with it's new configuration.
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void RefineAbstractType(TypeClass *Ty, const DerivedType *OldType,
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const Type *NewType) {
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#ifdef DEBUG_MERGE_TYPES
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DEBUG(dbgs() << "RefineAbstractType(" << (void*)OldType << "[" << *OldType
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<< "], " << (void*)NewType << " [" << *NewType << "])\n");
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// Otherwise, we are changing one subelement type into another. Clearly the
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// OldType must have been abstract, making us abstract.
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assert(Ty->isAbstract() && "Refining a non-abstract type!");
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assert(OldType != NewType);
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// Make a temporary type holder for the type so that it doesn't disappear on
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// us when we erase the entry from the map.
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PATypeHolder TyHolder = Ty;
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// The old record is now out-of-date, because one of the children has been
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// updated. Remove the obsolete entry from the map.
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unsigned NumErased = Map.erase(ValType::get(Ty));
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assert(NumErased && "Element not found!"); NumErased = NumErased;
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// Remember the structural hash for the type before we start hacking on it,
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// in case we need it later.
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unsigned OldTypeHash = ValType::hashTypeStructure(Ty);
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// Find the type element we are refining... and change it now!
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for (unsigned i = 0, e = Ty->getNumContainedTypes(); i != e; ++i)
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if (Ty->ContainedTys[i] == OldType)
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Ty->ContainedTys[i] = NewType;
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unsigned NewTypeHash = ValType::hashTypeStructure(Ty);
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// If there are no cycles going through this node, we can do a simple,
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// efficient lookup in the map, instead of an inefficient nasty linear
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if (!TypeHasCycleThroughItself(Ty)) {
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typename std::map<ValType, PATypeHolder>::iterator I;
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tie(I, Inserted) = Map.insert(std::make_pair(ValType::get(Ty), Ty));
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// Refined to a different type altogether?
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RemoveFromTypesByHash(OldTypeHash, Ty);
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// We already have this type in the table. Get rid of the newly refined
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TypeClass *NewTy = cast<TypeClass>((Type*)I->second.get());
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Ty->unlockedRefineAbstractTypeTo(NewTy);
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// Now we check to see if there is an existing entry in the table which is
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// structurally identical to the newly refined type. If so, this type
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// gets refined to the pre-existing type.
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std::multimap<unsigned, PATypeHolder>::iterator I, E, Entry;
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tie(I, E) = TypesByHash.equal_range(NewTypeHash);
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for (; I != E; ++I) {
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if (I->second == Ty) {
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// Remember the position of the old type if we see it in our scan.
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if (TypesEqual(Ty, I->second)) {
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TypeClass *NewTy = cast<TypeClass>((Type*)I->second.get());
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// Remove the old entry form TypesByHash. If the hash values differ
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// now, remove it from the old place. Otherwise, continue scanning
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// withing this hashcode to reduce work.
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if (NewTypeHash != OldTypeHash) {
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RemoveFromTypesByHash(OldTypeHash, Ty);
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// Find the location of Ty in the TypesByHash structure if we
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// haven't seen it already.
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while (I->second != Ty) {
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assert(I != E && "Structure doesn't contain type??");
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TypesByHash.erase(Entry);
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Ty->unlockedRefineAbstractTypeTo(NewTy);
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// If there is no existing type of the same structure, we reinsert an
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// updated record into the map.
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Map.insert(std::make_pair(ValType::get(Ty), Ty));
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// If the hash codes differ, update TypesByHash
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if (NewTypeHash != OldTypeHash) {
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RemoveFromTypesByHash(OldTypeHash, Ty);
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TypesByHash.insert(std::make_pair(NewTypeHash, Ty));
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// If the type is currently thought to be abstract, rescan all of our
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// subtypes to see if the type has just become concrete! Note that this
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// may send out notifications to AbstractTypeUsers that types become
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if (Ty->isAbstract())
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Ty->PromoteAbstractToConcrete();
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void print(const char *Arg) const {
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#ifdef DEBUG_MERGE_TYPES
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DEBUG(dbgs() << "TypeMap<>::" << Arg << " table contents:\n");
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for (typename std::map<ValType, PATypeHolder>::const_iterator I
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= Map.begin(), E = Map.end(); I != E; ++I)
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DEBUG(dbgs() << " " << (++i) << ". " << (void*)I->second.get() << " "
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<< *I->second.get() << "\n");
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void dump() const { print("dump output"); }