Factor some of the constants+context related code out into a separate header, to make LLVMContextImpl.h

not hideous.  Also, fix some MSVC compile errors.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78115 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 760 deletions

diff --git a/lib/VMCore/LLVMContextImpl.h b/lib/VMCore/LLVMContextImpl.h
index d7ad74fa1a..5a3056ad8f 100644
--- a/lib/VMCore/LLVMContextImpl.h
+++ b/lib/VMCore/LLVMContextImpl.h
@@ -15,776 +15,25 @@
 #ifndef LLVM_LLVMCONTEXT_IMPL_H
 #define LLVM_LLVMCONTEXT_IMPL_H
 
+#include "ConstantsContext.h"
 #include "llvm/LLVMContext.h"
 #include "llvm/Constants.h"
 #include "llvm/DerivedTypes.h"
-#include "llvm/Instructions.h"
-#include "llvm/Operator.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/System/Mutex.h"
 #include "llvm/System/RWMutex.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/StringMap.h"
-#include <map>
 #include <vector>
 
 namespace llvm {
-template<class ValType>
-struct ConstantTraits;
-
-
-/// UnaryConstantExpr - This class is private to Constants.cpp, and is used
-/// behind the scenes to implement unary constant exprs.
-class UnaryConstantExpr : public ConstantExpr {
-  void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
-public:
-  // allocate space for exactly one operand
-  void *operator new(size_t s) {
-    return User::operator new(s, 1);
-  }
-  UnaryConstantExpr(unsigned Opcode, Constant *C, const Type *Ty)
-    : ConstantExpr(Ty, Opcode, &Op<0>(), 1) {
-    Op<0>() = C;
-  }
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-/// BinaryConstantExpr - This class is private to Constants.cpp, and is used
-/// behind the scenes to implement binary constant exprs.
-class BinaryConstantExpr : public ConstantExpr {
-  void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
-public:
-  // allocate space for exactly two operands
-  void *operator new(size_t s) {
-    return User::operator new(s, 2);
-  }
-  BinaryConstantExpr(unsigned Opcode, Constant *C1, Constant *C2)
-    : ConstantExpr(C1->getType(), Opcode, &Op<0>(), 2) {
-    Op<0>() = C1;
-    Op<1>() = C2;
-  }
-  /// Transparently provide more efficient getOperand methods.
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-/// SelectConstantExpr - This class is private to Constants.cpp, and is used
-/// behind the scenes to implement select constant exprs.
-class SelectConstantExpr : public ConstantExpr {
-  void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
-public:
-  // allocate space for exactly three operands
-  void *operator new(size_t s) {
-    return User::operator new(s, 3);
-  }
-  SelectConstantExpr(Constant *C1, Constant *C2, Constant *C3)
-    : ConstantExpr(C2->getType(), Instruction::Select, &Op<0>(), 3) {
-    Op<0>() = C1;
-    Op<1>() = C2;
-    Op<2>() = C3;
-  }
-  /// Transparently provide more efficient getOperand methods.
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-/// ExtractElementConstantExpr - This class is private to
-/// Constants.cpp, and is used behind the scenes to implement
-/// extractelement constant exprs.
-class ExtractElementConstantExpr : public ConstantExpr {
-  void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
-public:
-  // allocate space for exactly two operands
-  void *operator new(size_t s) {
-    return User::operator new(s, 2);
-  }
-  ExtractElementConstantExpr(Constant *C1, Constant *C2)
-    : ConstantExpr(cast<VectorType>(C1->getType())->getElementType(), 
-                   Instruction::ExtractElement, &Op<0>(), 2) {
-    Op<0>() = C1;
-    Op<1>() = C2;
-  }
-  /// Transparently provide more efficient getOperand methods.
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-/// InsertElementConstantExpr - This class is private to
-/// Constants.cpp, and is used behind the scenes to implement
-/// insertelement constant exprs.
-class InsertElementConstantExpr : public ConstantExpr {
-  void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
-public:
-  // allocate space for exactly three operands
-  void *operator new(size_t s) {
-    return User::operator new(s, 3);
-  }
-  InsertElementConstantExpr(Constant *C1, Constant *C2, Constant *C3)
-    : ConstantExpr(C1->getType(), Instruction::InsertElement, 
-                   &Op<0>(), 3) {
-    Op<0>() = C1;
-    Op<1>() = C2;
-    Op<2>() = C3;
-  }
-  /// Transparently provide more efficient getOperand methods.
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-/// ShuffleVectorConstantExpr - This class is private to
-/// Constants.cpp, and is used behind the scenes to implement
-/// shufflevector constant exprs.
-class ShuffleVectorConstantExpr : public ConstantExpr {
-  void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
-public:
-  // allocate space for exactly three operands
-  void *operator new(size_t s) {
-    return User::operator new(s, 3);
-  }
-  ShuffleVectorConstantExpr(Constant *C1, Constant *C2, Constant *C3)
-  : ConstantExpr(VectorType::get(
-                   cast<VectorType>(C1->getType())->getElementType(),
-                   cast<VectorType>(C3->getType())->getNumElements()),
-                 Instruction::ShuffleVector, 
-                 &Op<0>(), 3) {
-    Op<0>() = C1;
-    Op<1>() = C2;
-    Op<2>() = C3;
-  }
-  /// Transparently provide more efficient getOperand methods.
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-/// ExtractValueConstantExpr - This class is private to
-/// Constants.cpp, and is used behind the scenes to implement
-/// extractvalue constant exprs.
-class ExtractValueConstantExpr : public ConstantExpr {
-  void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
-public:
-  // allocate space for exactly one operand
-  void *operator new(size_t s) {
-    return User::operator new(s, 1);
-  }
-  ExtractValueConstantExpr(Constant *Agg,
-                           const SmallVector<unsigned, 4> &IdxList,
-                           const Type *DestTy)
-    : ConstantExpr(DestTy, Instruction::ExtractValue, &Op<0>(), 1),
-      Indices(IdxList) {
-    Op<0>() = Agg;
-  }
-
-  /// Indices - These identify which value to extract.
-  const SmallVector<unsigned, 4> Indices;
-
-  /// Transparently provide more efficient getOperand methods.
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-/// InsertValueConstantExpr - This class is private to
-/// Constants.cpp, and is used behind the scenes to implement
-/// insertvalue constant exprs.
-class InsertValueConstantExpr : public ConstantExpr {
-  void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
-public:
-  // allocate space for exactly one operand
-  void *operator new(size_t s) {
-    return User::operator new(s, 2);
-  }
-  InsertValueConstantExpr(Constant *Agg, Constant *Val,
-                          const SmallVector<unsigned, 4> &IdxList,
-                          const Type *DestTy)
-    : ConstantExpr(DestTy, Instruction::InsertValue, &Op<0>(), 2),
-      Indices(IdxList) {
-    Op<0>() = Agg;
-    Op<1>() = Val;
-  }
-
-  /// Indices - These identify the position for the insertion.
-  const SmallVector<unsigned, 4> Indices;
-
-  /// Transparently provide more efficient getOperand methods.
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-
-/// GetElementPtrConstantExpr - This class is private to Constants.cpp, and is
-/// used behind the scenes to implement getelementpr constant exprs.
-class GetElementPtrConstantExpr : public ConstantExpr {
-  GetElementPtrConstantExpr(Constant *C, const std::vector<Constant*> &IdxList,
-                            const Type *DestTy);
-public:
-  static GetElementPtrConstantExpr *Create(Constant *C,
-                                           const std::vector<Constant*>&IdxList,
-                                           const Type *DestTy) {
-    return
-      new(IdxList.size() + 1) GetElementPtrConstantExpr(C, IdxList, DestTy);
-  }
-  /// Transparently provide more efficient getOperand methods.
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-// CompareConstantExpr - This class is private to Constants.cpp, and is used
-// behind the scenes to implement ICmp and FCmp constant expressions. This is
-// needed in order to store the predicate value for these instructions.
-struct CompareConstantExpr : public ConstantExpr {
-  void *operator new(size_t, unsigned);  // DO NOT IMPLEMENT
-  // allocate space for exactly two operands
-  void *operator new(size_t s) {
-    return User::operator new(s, 2);
-  }
-  unsigned short predicate;
-  CompareConstantExpr(const Type *ty, Instruction::OtherOps opc,
-                      unsigned short pred,  Constant* LHS, Constant* RHS)
-    : ConstantExpr(ty, opc, &Op<0>(), 2), predicate(pred) {
-    Op<0>() = LHS;
-    Op<1>() = RHS;
-  }
-  /// Transparently provide more efficient getOperand methods.
-  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
-};
-
-template <>
-struct OperandTraits<UnaryConstantExpr> : FixedNumOperandTraits<1> {
-};
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(UnaryConstantExpr, Value)
-
-template <>
-struct OperandTraits<BinaryConstantExpr> : FixedNumOperandTraits<2> {
-};
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BinaryConstantExpr, Value)
-
-template <>
-struct OperandTraits<SelectConstantExpr> : FixedNumOperandTraits<3> {
-};
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(SelectConstantExpr, Value)
-
-template <>
-struct OperandTraits<ExtractElementConstantExpr> : FixedNumOperandTraits<2> {
-};
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ExtractElementConstantExpr, Value)
-
-template <>
-struct OperandTraits<InsertElementConstantExpr> : FixedNumOperandTraits<3> {
-};
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertElementConstantExpr, Value)
-
-template <>
-struct OperandTraits<ShuffleVectorConstantExpr> : FixedNumOperandTraits<3> {
-};
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ShuffleVectorConstantExpr, Value)
-
-template <>
-struct OperandTraits<ExtractValueConstantExpr> : FixedNumOperandTraits<1> {
-};
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ExtractValueConstantExpr, Value)
-
-template <>
-struct OperandTraits<InsertValueConstantExpr> : FixedNumOperandTraits<2> {
-};
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertValueConstantExpr, Value)
-
-template <>
-struct OperandTraits<GetElementPtrConstantExpr> : VariadicOperandTraits<1> {
-};
-
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GetElementPtrConstantExpr, Value)
-
-
-template <>
-struct OperandTraits<CompareConstantExpr> : FixedNumOperandTraits<2> {
-};
-DEFINE_TRANSPARENT_OPERAND_ACCESSORS(CompareConstantExpr, Value)
-
-struct ExprMapKeyType {
-  typedef SmallVector<unsigned, 4> IndexList;
-
-  ExprMapKeyType(unsigned opc,
-      const std::vector<Constant*> &ops,
-      unsigned short pred = 0,
-      const IndexList &inds = IndexList())
-        : opcode(opc), predicate(pred), operands(ops), indices(inds) {}
-  uint16_t opcode;
-  uint16_t predicate;
-  std::vector<Constant*> operands;
-  IndexList indices;
-  bool operator==(const ExprMapKeyType& that) const {
-    return this->opcode == that.opcode &&
-           this->predicate == that.predicate &&
-           this->operands == that.operands &&
-           this->indices == that.indices;
-  }
-  bool operator<(const ExprMapKeyType & that) const {
-    return this->opcode < that.opcode ||
-      (this->opcode == that.opcode && this->predicate < that.predicate) ||
-      (this->opcode == that.opcode && this->predicate == that.predicate &&
-       this->operands < that.operands) ||
-      (this->opcode == that.opcode && this->predicate == that.predicate &&
-       this->operands == that.operands && this->indices < that.indices);
-  }
-
-  bool operator!=(const ExprMapKeyType& that) const {
-    return !(*this == that);
-  }
-};
-
-// The number of operands for each ConstantCreator::create method is
-// determined by the ConstantTraits template.
-// ConstantCreator - A class that is used to create constants by
-// ValueMap*.  This class should be partially specialized if there is
-// something strange that needs to be done to interface to the ctor for the
-// constant.
-//
-template<typename T, typename Alloc>
-struct ConstantTraits< std::vector<T, Alloc> > {
-  static unsigned uses(const std::vector<T, Alloc>& v) {
-    return v.size();
-  }
-};
-
-template<class ConstantClass, class TypeClass, class ValType>
-struct ConstantCreator {
-  static ConstantClass *create(const TypeClass *Ty, const ValType &V) {
-    return new(ConstantTraits<ValType>::uses(V)) ConstantClass(Ty, V);
-  }
-};
-
-template<class ConstantClass, class TypeClass>
-struct ConvertConstantType {
-  static void convert(ConstantClass *OldC, const TypeClass *NewTy) {
-    llvm_unreachable("This type cannot be converted!");
-  }
-};
-
-template<>
-struct ConstantCreator<ConstantExpr, Type, ExprMapKeyType> {
-  static ConstantExpr *create(const Type *Ty, const ExprMapKeyType &V,
-      unsigned short pred = 0) {
-    if (Instruction::isCast(V.opcode))
-      return new UnaryConstantExpr(V.opcode, V.operands[0], Ty);
-    if ((V.opcode >= Instruction::BinaryOpsBegin &&
-         V.opcode < Instruction::BinaryOpsEnd))
-      return new BinaryConstantExpr(V.opcode, V.operands[0], V.operands[1]);
-    if (V.opcode == Instruction::Select)
-      return new SelectConstantExpr(V.operands[0], V.operands[1], 
-                                    V.operands[2]);
-    if (V.opcode == Instruction::ExtractElement)
-      return new ExtractElementConstantExpr(V.operands[0], V.operands[1]);
-    if (V.opcode == Instruction::InsertElement)
-      return new InsertElementConstantExpr(V.operands[0], V.operands[1],
-                                           V.operands[2]);
-    if (V.opcode == Instruction::ShuffleVector)
-      return new ShuffleVectorConstantExpr(V.operands[0], V.operands[1],
-                                           V.operands[2]);
-    if (V.opcode == Instruction::InsertValue)
-      return new InsertValueConstantExpr(V.operands[0], V.operands[1],
-                                         V.indices, Ty);
-    if (V.opcode == Instruction::ExtractValue)
-      return new ExtractValueConstantExpr(V.operands[0], V.indices, Ty);
-    if (V.opcode == Instruction::GetElementPtr) {
-      std::vector<Constant*> IdxList(V.operands.begin()+1, V.operands.end());
-      return GetElementPtrConstantExpr::Create(V.operands[0], IdxList, Ty);
-    }
-
-    // The compare instructions are weird. We have to encode the predicate
-    // value and it is combined with the instruction opcode by multiplying
-    // the opcode by one hundred. We must decode this to get the predicate.
-    if (V.opcode == Instruction::ICmp)
-      return new CompareConstantExpr(Ty, Instruction::ICmp, V.predicate, 
-                                     V.operands[0], V.operands[1]);
-    if (V.opcode == Instruction::FCmp) 
-      return new CompareConstantExpr(Ty, Instruction::FCmp, V.predicate, 
-                                     V.operands[0], V.operands[1]);
-    llvm_unreachable("Invalid ConstantExpr!");
-    return 0;
-  }
-};
-
-template<>
-struct ConvertConstantType<ConstantExpr, Type> {
-  static void convert(ConstantExpr *OldC, const Type *NewTy) {
-    Constant *New;
-    switch (OldC->getOpcode()) {
-    case Instruction::Trunc:
-    case Instruction::ZExt:
-    case Instruction::SExt:
-    case Instruction::FPTrunc:
-    case Instruction::FPExt:
-    case Instruction::UIToFP:
-    case Instruction::SIToFP:
-    case Instruction::FPToUI:
-    case Instruction::FPToSI:
-    case Instruction::PtrToInt:
-    case Instruction::IntToPtr:
-    case Instruction::BitCast:
-      New = ConstantExpr::getCast(OldC->getOpcode(), OldC->getOperand(0), 
-                                  NewTy);
-      break;
-    case Instruction::Select:
-      New = ConstantExpr::getSelectTy(NewTy, OldC->getOperand(0),
-                                      OldC->getOperand(1),
-                                      OldC->getOperand(2));
-      break;
-    default:
-      assert(OldC->getOpcode() >= Instruction::BinaryOpsBegin &&
-             OldC->getOpcode() <  Instruction::BinaryOpsEnd);
-      New = ConstantExpr::getTy(NewTy, OldC->getOpcode(), OldC->getOperand(0),
-                                OldC->getOperand(1));
-      break;
-    case Instruction::GetElementPtr:
-      // Make everyone now use a constant of the new type...
-      std::vector<Value*> Idx(OldC->op_begin()+1, OldC->op_end());
-      New = ConstantExpr::getGetElementPtrTy(NewTy, OldC->getOperand(0),
-                                             &Idx[0], Idx.size());
-      break;
-    }
-
-    assert(New != OldC && "Didn't replace constant??");
-    OldC->uncheckedReplaceAllUsesWith(New);
-    OldC->destroyConstant();    // This constant is now dead, destroy it.
-  }
-};
-
-// ConstantAggregateZero does not take extra "value" argument...
-template<class ValType>
-struct ConstantCreator<ConstantAggregateZero, Type, ValType> {
-  static ConstantAggregateZero *create(const Type *Ty, const ValType &V){
-    return new ConstantAggregateZero(Ty);
-  }
-};
-
-template<>
-struct ConvertConstantType<ConstantVector, VectorType> {
-  static void convert(ConstantVector *OldC, const VectorType *NewTy) {
-    // Make everyone now use a constant of the new type...
-    std::vector<Constant*> C;
-    for (unsigned i = 0, e = OldC->getNumOperands(); i != e; ++i)
-      C.push_back(cast<Constant>(OldC->getOperand(i)));
-    Constant *New = ConstantVector::get(NewTy, C);
-    assert(New != OldC && "Didn't replace constant??");
-    OldC->uncheckedReplaceAllUsesWith(New);
-    OldC->destroyConstant();    // This constant is now dead, destroy it.
-  }
-};
-
-template<>
-struct ConvertConstantType<ConstantAggregateZero, Type> {
-  static void convert(ConstantAggregateZero *OldC, const Type *NewTy) {
-    // Make everyone now use a constant of the new type...
-    Constant *New = ConstantAggregateZero::get(NewTy);
-    assert(New != OldC && "Didn't replace constant??");
-    OldC->uncheckedReplaceAllUsesWith(New);
-    OldC->destroyConstant();     // This constant is now dead, destroy it.
-  }
-};
-
-template<>
-struct ConvertConstantType<ConstantArray, ArrayType> {
-  static void convert(ConstantArray *OldC, const ArrayType *NewTy) {
-    // Make everyone now use a constant of the new type...
-    std::vector<Constant*> C;
-    for (unsigned i = 0, e = OldC->getNumOperands(); i != e; ++i)
-      C.push_back(cast<Constant>(OldC->getOperand(i)));
-    Constant *New = ConstantArray::get(NewTy, C);
-    assert(New != OldC && "Didn't replace constant??");
-    OldC->uncheckedReplaceAllUsesWith(New);
-    OldC->destroyConstant();    // This constant is now dead, destroy it.
-  }
-};
-
-template<>
-struct ConvertConstantType<ConstantStruct, StructType> {
-  static void convert(ConstantStruct *OldC, const StructType *NewTy) {
-    // Make everyone now use a constant of the new type...
-    std::vector<Constant*> C;
-    for (unsigned i = 0, e = OldC->getNumOperands(); i != e; ++i)
-      C.push_back(cast<Constant>(OldC->getOperand(i)));
-    Constant *New = ConstantStruct::get(NewTy, C);
-    assert(New != OldC && "Didn't replace constant??");
-
-    OldC->uncheckedReplaceAllUsesWith(New);
-    OldC->destroyConstant();    // This constant is now dead, destroy it.
-  }
-};
-
-// ConstantPointerNull does not take extra "value" argument...
-template<class ValType>
-struct ConstantCreator<ConstantPointerNull, PointerType, ValType> {
-  static ConstantPointerNull *create(const PointerType *Ty, const ValType &V){
-    return new ConstantPointerNull(Ty);
-  }
-};
-
-template<>
-struct ConvertConstantType<ConstantPointerNull, PointerType> {
-  static void convert(ConstantPointerNull *OldC, const PointerType *NewTy) {
-    // Make everyone now use a constant of the new type...
-    Constant *New = ConstantPointerNull::get(NewTy);
-    assert(New != OldC && "Didn't replace constant??");
-    OldC->uncheckedReplaceAllUsesWith(New);
-    OldC->destroyConstant();     // This constant is now dead, destroy it.
-  }
-};
-
-// UndefValue does not take extra "value" argument...
-template<class ValType>
-struct ConstantCreator<UndefValue, Type, ValType> {
-  static UndefValue *create(const Type *Ty, const ValType &V) {
-    return new UndefValue(Ty);
-  }
-};
-
-template<>
-struct ConvertConstantType<UndefValue, Type> {
-  static void convert(UndefValue *OldC, const Type *NewTy) {
-    // Make everyone now use a constant of the new type.
-    Constant *New = UndefValue::get(NewTy);
-    assert(New != OldC && "Didn't replace constant??");
-    OldC->uncheckedReplaceAllUsesWith(New);
-    OldC->destroyConstant();     // This constant is now dead, destroy it.
-  }
-};
-
-template<class ValType, class TypeClass, class ConstantClass,
-         bool HasLargeKey = false /*true for arrays and structs*/ >
-class ValueMap : public AbstractTypeUser {
-public:
-  typedef std::pair<const Type*, ValType> MapKey;
-  typedef std::map<MapKey, Constant *> MapTy;
-  typedef std::map<Constant*, typename MapTy::iterator> InverseMapTy;
-  typedef std::map<const Type*, typename MapTy::iterator> AbstractTypeMapTy;
-private:
-  /// Map - This is the main map from the element descriptor to the Constants.
-  /// This is the primary way we avoid creating two of the same shape
-  /// constant.
-  MapTy Map;
-    
-  /// InverseMap - If "HasLargeKey" is true, this contains an inverse mapping
-  /// from the constants to their element in Map.  This is important for
-  /// removal of constants from the array, which would otherwise have to scan
-  /// through the map with very large keys.
-  InverseMapTy InverseMap;
-
-  /// AbstractTypeMap - Map for abstract type constants.
-  ///
-  AbstractTypeMapTy AbstractTypeMap;
-    
-  /// ValueMapLock - Mutex for this map.
-  sys::SmartMutex<true> ValueMapLock;
-
-public:
-  // NOTE: This function is not locked.  It is the caller's responsibility
-  // to enforce proper synchronization.
-  typename MapTy::iterator map_end() { return Map.end(); }
-    
-  /// InsertOrGetItem - Return an iterator for the specified element.
-  /// If the element exists in the map, the returned iterator points to the
-  /// entry and Exists=true.  If not, the iterator points to the newly
-  /// inserted entry and returns Exists=false.  Newly inserted entries have
-  /// I->second == 0, and should be filled in.
-  /// NOTE: This function is not locked.  It is the caller's responsibility
-  // to enforce proper synchronization.
-  typename MapTy::iterator InsertOrGetItem(std::pair<MapKey, Constant *>
-                                 &InsertVal,
-                                 bool &Exists) {
-    std::pair<typename MapTy::iterator, bool> IP = Map.insert(InsertVal);
-    Exists = !IP.second;
-    return IP.first;
-  }
-    
-private:
-  typename MapTy::iterator FindExistingElement(ConstantClass *CP) {
-    if (HasLargeKey) {
-      typename InverseMapTy::iterator IMI = InverseMap.find(CP);
-      assert(IMI != InverseMap.end() && IMI->second != Map.end() &&
-             IMI->second->second == CP &&
-             "InverseMap corrupt!");
-      return IMI->second;
-    }
-      
-    typename MapTy::iterator I =
-      Map.find(MapKey(static_cast<const TypeClass*>(CP->getRawType()),
-                      getValType(CP)));
-    if (I == Map.end() || I->second != CP) {
-      // FIXME: This should not use a linear scan.  If this gets to be a
-      // performance problem, someone should look at this.
-      for (I = Map.begin(); I != Map.end() && I->second != CP; ++I)
-        /* empty */;
-    }
-    return I;
-  }
-    
-  ConstantClass* Create(const TypeClass *Ty, const ValType &V,
-                        typename MapTy::iterator I) {
-    ConstantClass* Result =
-      ConstantCreator<ConstantClass,TypeClass,ValType>::create(Ty, V);
-
-    assert(Result->getType() == Ty && "Type specified is not correct!");
-    I = Map.insert(I, std::make_pair(MapKey(Ty, V), Result));
-
-    if (HasLargeKey)  // Remember the reverse mapping if needed.
-      InverseMap.insert(std::make_pair(Result, I));
-
-    // If the type of the constant is abstract, make sure that an entry
-    // exists for it in the AbstractTypeMap.
-    if (Ty->isAbstract()) {
-      typename AbstractTypeMapTy::iterator TI = 
-                                               AbstractTypeMap.find(Ty);
-
-      if (TI == AbstractTypeMap.end()) {
-        // Add ourselves to the ATU list of the type.
-        cast<DerivedType>(Ty)->addAbstractTypeUser(this);
-
-        AbstractTypeMap.insert(TI, std::make_pair(Ty, I));
-      }
-    }
-      
-    return Result;
-  }
-public:
-    
-  /// getOrCreate - Return the specified constant from the map, creating it if
-  /// necessary.
-  ConstantClass *getOrCreate(const TypeClass *Ty, const ValType &V) {
-    sys::SmartScopedLock<true> Lock(ValueMapLock);
-    MapKey Lookup(Ty, V);
-    ConstantClass* Result = 0;
-    
-    typename MapTy::iterator I = Map.find(Lookup);
-    // Is it in the map?  
-    if (I != Map.end())
-      Result = static_cast<ConstantClass *>(I->second);
-        
-    if (!Result) {
-      // If no preexisting value, create one now...
-      Result = Create(Ty, V, I);
-    }
-        
-    return Result;
-  }
-
-  void remove(ConstantClass *CP) {
-    sys::SmartScopedLock<true> Lock(ValueMapLock);
-    typename MapTy::iterator I = FindExistingElement(CP);
-    assert(I != Map.end() && "Constant not found in constant table!");
-    assert(I->second == CP && "Didn't find correct element?");
-
-    if (HasLargeKey)  // Remember the reverse mapping if needed.
-      InverseMap.erase(CP);
-      
-    // Now that we found the entry, make sure this isn't the entry that
-    // the AbstractTypeMap points to.
-    const TypeClass *Ty = static_cast<const TypeClass *>(I->first.first);
-    if (Ty->isAbstract()) {
-      assert(AbstractTypeMap.count(Ty) &&
-             "Abstract type not in AbstractTypeMap?");
-      typename MapTy::iterator &ATMEntryIt = AbstractTypeMap[Ty];
-      if (ATMEntryIt == I) {
-        // Yes, we are removing the representative entry for this type.
-        // See if there are any other entries of the same type.
-        typename MapTy::iterator TmpIt = ATMEntryIt;
-
-        // First check the entry before this one...
-        if (TmpIt != Map.begin()) {
-          --TmpIt;
-          if (TmpIt->first.first != Ty) // Not the same type, move back...
-            ++TmpIt;
-        }
-
-        // If we didn't find the same type, try to move forward...
-        if (TmpIt == ATMEntryIt) {
-          ++TmpIt;
-          if (TmpIt == Map.end() || TmpIt->first.first != Ty)
-            --TmpIt;   // No entry afterwards with the same type
-        }
-
-        // If there is another entry in the map of the same abstract type,
-        // update the AbstractTypeMap entry now.
-        if (TmpIt != ATMEntryIt) {
-          ATMEntryIt = TmpIt;
-        } else {
-          // Otherwise, we are removing the last instance of this type
-          // from the table.  Remove from the ATM, and from user list.
-          cast<DerivedType>(Ty)->removeAbstractTypeUser(this);
-          AbstractTypeMap.erase(Ty);
-        }
-      }
-    }
-
-    Map.erase(I);
-  }
-
-    
-  /// MoveConstantToNewSlot - If we are about to change C to be the element
-  /// specified by I, update our internal data structures to reflect this
-  /// fact.
-  /// NOTE: This function is not locked. It is the responsibility of the
-  /// caller to enforce proper synchronization if using this method.
-  void MoveConstantToNewSlot(ConstantClass *C, typename MapTy::iterator I) {
-    // First, remove the old location of the specified constant in the map.
-    typename MapTy::iterator OldI = FindExistingElement(C);
-    assert(OldI != Map.end() && "Constant not found in constant table!");
-    assert(OldI->second == C && "Didn't find correct element?");
-      
-    // If this constant is the representative element for its abstract type,
-    // update the AbstractTypeMap so that the representative element is I.
-    if (C->getType()->isAbstract()) {
-      typename AbstractTypeMapTy::iterator ATI =
-          AbstractTypeMap.find(C->getType());
-      assert(ATI != AbstractTypeMap.end() &&
-             "Abstract type not in AbstractTypeMap?");
-      if (ATI->second == OldI)
-        ATI->second = I;
-    }
-      
-    // Remove the old entry from the map.
-    Map.erase(OldI);
-    
-    // Update the inverse map so that we know that this constant is now
-    // located at descriptor I.
-    if (HasLargeKey) {
-      assert(I->second == C && "Bad inversemap entry!");
-      InverseMap[C] = I;
-    }
-  }
-    
-  void refineAbstractType(const DerivedType *OldTy, const Type *NewTy) {
-    sys::SmartScopedLock<true> Lock(ValueMapLock);
-    typename AbstractTypeMapTy::iterator I =
-      AbstractTypeMap.find(cast<Type>(OldTy));
-
-    assert(I != AbstractTypeMap.end() &&
-           "Abstract type not in AbstractTypeMap?");
-
-    // Convert a constant at a time until the last one is gone.  The last one
-    // leaving will remove() itself, causing the AbstractTypeMapEntry to be
-    // eliminated eventually.
-    do {
-      ConvertConstantType<ConstantClass,
-                          TypeClass>::convert(
-                              static_cast<ConstantClass *>(I->second->second),
-                                              cast<TypeClass>(NewTy));
-
-      I = AbstractTypeMap.find(cast<Type>(OldTy));
-    } while (I != AbstractTypeMap.end());
-  }
-
-  // If the type became concrete without being refined to any other existing
-  // type, we just remove ourselves from the ATU list.
-  void typeBecameConcrete(const DerivedType *AbsTy) {
-    AbsTy->removeAbstractTypeUser(this);
-  }
-
-  void dump() const {
-    DOUT << "Constant.cpp: ValueMap\n";
-  }
-};
-
 
 class ConstantInt;
 class ConstantFP;
 class MDString;
 class MDNode;
-class LLVMContext;
+struct LLVMContext;
 class Type;
 class Value;
 
@@ -844,11 +93,11 @@ struct LLVMContextImpl {
   sys::SmartRWMutex<true> ConstantsLock;
   
   typedef DenseMap<DenseMapAPIntKeyInfo::KeyTy, ConstantInt*, 
-                   DenseMapAPIntKeyInfo> IntMapTy;
+                         DenseMapAPIntKeyInfo> IntMapTy;
   IntMapTy IntConstants;
   
   typedef DenseMap<DenseMapAPFloatKeyInfo::KeyTy, ConstantFP*, 
-                   DenseMapAPFloatKeyInfo> FPMapTy;
+                         DenseMapAPFloatKeyInfo> FPMapTy;
   FPMapTy FPConstants;
   
   StringMap<MDString*> MDStringCache;
@@ -875,14 +124,10 @@ struct LLVMContextImpl {
   
   ValueMap<ExprMapKeyType, Type, ConstantExpr> ExprConstants;
   
-  LLVMContext &Context;
   ConstantInt *TheTrueVal;
   ConstantInt *TheFalseVal;
   
-  LLVMContextImpl(LLVMContext &C);
-private:
-  LLVMContextImpl();
-  LLVMContextImpl(const LLVMContextImpl&);
+  LLVMContextImpl() : TheTrueVal(0), TheFalseVal(0) { }
 };
 
 }