1 //===-- llvm/Type.h - Classes for handling data types -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
14 #include "llvm/AbstractTypeUser.h"
15 #include "llvm/Support/Casting.h"
16 #include "llvm/Support/DataTypes.h"
17 #include "llvm/Support/Streams.h"
18 #include "llvm/ADT/GraphTraits.h"
19 #include "llvm/ADT/iterator.h"
30 /// This file contains the declaration of the Type class. For more "Type" type
31 /// stuff, look in DerivedTypes.h.
33 /// The instances of the Type class are immutable: once they are created,
34 /// they are never changed. Also note that only one instance of a particular
35 /// type is ever created. Thus seeing if two types are equal is a matter of
36 /// doing a trivial pointer comparison. To enforce that no two equal instances
37 /// are created, Type instances can only be created via static factory methods
38 /// in class Type and in derived classes.
40 /// Once allocated, Types are never free'd, unless they are an abstract type
41 /// that is resolved to a more concrete type.
43 /// Types themself don't have a name, and can be named either by:
44 /// - using SymbolTable instance, typically from some Module,
45 /// - using convenience methods in the Module class (which uses module's
48 /// Opaque types are simple derived types with no state. There may be many
49 /// different Opaque type objects floating around, but two are only considered
50 /// identical if they are pointer equals of each other. This allows us to have
51 /// two opaque types that end up resolving to different concrete types later.
53 /// Opaque types are also kinda weird and scary and different because they have
54 /// to keep a list of uses of the type. When, through linking, parsing, or
55 /// bitcode reading, they become resolved, they need to find and update all
56 /// users of the unknown type, causing them to reference a new, more concrete
57 /// type. Opaque types are deleted when their use list dwindles to zero users.
59 /// @brief Root of type hierarchy
60 class Type : public AbstractTypeUser {
62 //===-------------------------------------------------------------------===//
63 /// Definitions of all of the base types for the Type system. Based on this
64 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
65 /// Note: If you add an element to this, you need to add an element to the
66 /// Type::getPrimitiveType function, or else things will break!
69 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date
70 VoidTyID = 0, ///< 0: type with no size
71 FloatTyID, ///< 1: 32 bit floating point type
72 DoubleTyID, ///< 2: 64 bit floating point type
73 X86_FP80TyID, ///< 3: 80 bit floating point type (X87)
74 FP128TyID, ///< 4: 128 bit floating point type (112-bit mantissa)
75 PPC_FP128TyID, ///< 5: 128 bit floating point type (two 64-bits)
76 LabelTyID, ///< 6: Labels
78 // Derived types... see DerivedTypes.h file...
79 // Make sure FirstDerivedTyID stays up to date!!!
80 IntegerTyID, ///< 7: Arbitrary bit width integers
81 FunctionTyID, ///< 8: Functions
82 StructTyID, ///< 9: Structures
83 ArrayTyID, ///< 10: Arrays
84 PointerTyID, ///< 11: Pointers
85 OpaqueTyID, ///< 12: Opaque: type with unknown structure
86 VectorTyID, ///< 13: SIMD 'packed' format, or other vector type
88 NumTypeIDs, // Must remain as last defined ID
89 LastPrimitiveTyID = LabelTyID,
90 FirstDerivedTyID = IntegerTyID
94 TypeID ID : 8; // The current base type of this type.
95 bool Abstract : 1; // True if type contains an OpaqueType
96 unsigned SubclassData : 23; //Space for subclasses to store data
98 /// RefCount - This counts the number of PATypeHolders that are pointing to
99 /// this type. When this number falls to zero, if the type is abstract and
100 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for
103 mutable unsigned RefCount;
105 const Type *getForwardedTypeInternal() const;
107 // Some Type instances are allocated as arrays, some aren't. So we provide
108 // this method to get the right kind of destruction for the type of Type.
109 void destroy() const; // const is a lie, this does "delete this"!
112 explicit Type(TypeID id) : ID(id), Abstract(false), SubclassData(0),
113 RefCount(0), ForwardType(0), NumContainedTys(0),
116 assert(AbstractTypeUsers.empty() && "Abstract types remain");
119 /// Types can become nonabstract later, if they are refined.
121 inline void setAbstract(bool Val) { Abstract = Val; }
123 unsigned getRefCount() const { return RefCount; }
125 unsigned getSubclassData() const { return SubclassData; }
126 void setSubclassData(unsigned val) { SubclassData = val; }
128 /// ForwardType - This field is used to implement the union find scheme for
129 /// abstract types. When types are refined to other types, this field is set
130 /// to the more refined type. Only abstract types can be forwarded.
131 mutable const Type *ForwardType;
134 /// AbstractTypeUsers - Implement a list of the users that need to be notified
135 /// if I am a type, and I get resolved into a more concrete type.
137 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers;
139 /// NumContainedTys - Keeps track of how many PATypeHandle instances there
140 /// are at the end of this type instance for the list of contained types. It
141 /// is the subclasses responsibility to set this up. Set to 0 if there are no
142 /// contained types in this type.
143 unsigned NumContainedTys;
145 /// ContainedTys - A pointer to the array of Types (PATypeHandle) contained
146 /// by this Type. For example, this includes the arguments of a function
147 /// type, the elements of a structure, the pointee of a pointer, the element
148 /// type of an array, etc. This pointer may be 0 for types that don't
149 /// contain other types (Integer, Double, Float). In general, the subclass
150 /// should arrange for space for the PATypeHandles to be included in the
151 /// allocation of the type object and set this pointer to the address of the
152 /// first element. This allows the Type class to manipulate the ContainedTys
153 /// without understanding the subclass's placement for this array. keeping
154 /// it here also allows the subtype_* members to be implemented MUCH more
155 /// efficiently, and dynamically very few types do not contain any elements.
156 PATypeHandle *ContainedTys;
159 void print(std::ostream &O) const;
160 void print(std::ostream *O) const { if (O) print(*O); }
162 /// @brief Debugging support: print to stderr
165 //===--------------------------------------------------------------------===//
166 // Property accessors for dealing with types... Some of these virtual methods
167 // are defined in private classes defined in Type.cpp for primitive types.
170 /// getTypeID - Return the type id for the type. This will return one
171 /// of the TypeID enum elements defined above.
173 inline TypeID getTypeID() const { return ID; }
175 /// getDescription - Return the string representation of the type...
176 const std::string &getDescription() const;
178 /// isInteger - True if this is an instance of IntegerType.
180 bool isInteger() const { return ID == IntegerTyID; }
182 /// isIntOrIntVector - Return true if this is an integer type or a vector of
185 bool isIntOrIntVector() const;
187 /// isFloatingPoint - Return true if this is one of the two floating point
189 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID ||
190 ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; }
192 /// isFPOrFPVector - Return true if this is a FP type or a vector of FP types.
194 bool isFPOrFPVector() const;
196 /// isAbstract - True if the type is either an Opaque type, or is a derived
197 /// type that includes an opaque type somewhere in it.
199 inline bool isAbstract() const { return Abstract; }
201 /// canLosslesslyBitCastTo - Return true if this type could be converted
202 /// with a lossless BitCast to type 'Ty'. For example, uint to int. BitCasts
203 /// are valid for types of the same size only where no re-interpretation of
204 /// the bits is done.
205 /// @brief Determine if this type could be losslessly bitcast to Ty
206 bool canLosslesslyBitCastTo(const Type *Ty) const;
209 /// Here are some useful little methods to query what type derived types are
210 /// Note that all other types can just compare to see if this == Type::xxxTy;
212 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
213 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
215 /// isFirstClassType - Return true if the type is "first class", meaning it
216 /// is a valid type for a Value.
218 inline bool isFirstClassType() const {
219 // There are more first-class kinds than non-first-class kinds, so a
220 // negative test is simpler than a positive one.
221 return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID;
224 /// isSingleValueType - Return true if the type is a valid type for a
225 /// virtual register in codegen. This includes all first-class types
226 /// except struct and array types.
228 inline bool isSingleValueType() const {
229 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
230 ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID;
233 /// isAggregateType - Return true if the type is an aggregate type. This
234 /// means it is valid as the first operand of an insertvalue or
235 /// extractvalue instruction. This includes struct and array types, but
236 /// does not include vector types.
238 inline bool isAggregateType() const {
239 return ID == StructTyID || ID == ArrayTyID;
242 /// isSized - Return true if it makes sense to take the size of this type. To
243 /// get the actual size for a particular target, it is reasonable to use the
244 /// TargetData subsystem to do this.
246 bool isSized() const {
247 // If it's a primitive, it is always sized.
248 if (ID == IntegerTyID || isFloatingPoint() || ID == PointerTyID)
250 // If it is not something that can have a size (e.g. a function or label),
251 // it doesn't have a size.
252 if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID)
254 // If it is something that can have a size and it's concrete, it definitely
255 // has a size, otherwise we have to try harder to decide.
256 return !isAbstract() || isSizedDerivedType();
259 /// getPrimitiveSizeInBits - Return the basic size of this type if it is a
260 /// primitive type. These are fixed by LLVM and are not target dependent.
261 /// This will return zero if the type does not have a size or is not a
264 unsigned getPrimitiveSizeInBits() const;
266 /// getFPMantissaWidth - Return the width of the mantissa of this type. This
267 /// is only valid on scalar floating point types. If the FP type does not
268 /// have a stable mantissa (e.g. ppc long double), this method returns -1.
269 int getFPMantissaWidth() const {
270 assert(isFloatingPoint() && "Not a floating point type!");
271 if (ID == FloatTyID) return 24;
272 if (ID == DoubleTyID) return 53;
273 if (ID == X86_FP80TyID) return 64;
274 if (ID == FP128TyID) return 113;
275 assert(ID == PPC_FP128TyID && "unknown fp type");
279 /// getForwardedType - Return the type that this type has been resolved to if
280 /// it has been resolved to anything. This is used to implement the
281 /// union-find algorithm for type resolution, and shouldn't be used by general
283 const Type *getForwardedType() const {
284 if (!ForwardType) return 0;
285 return getForwardedTypeInternal();
288 /// getVAArgsPromotedType - Return the type an argument of this type
289 /// will be promoted to if passed through a variable argument
291 const Type *getVAArgsPromotedType() const;
293 //===--------------------------------------------------------------------===//
294 // Type Iteration support
296 typedef PATypeHandle *subtype_iterator;
297 subtype_iterator subtype_begin() const { return ContainedTys; }
298 subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
300 /// getContainedType - This method is used to implement the type iterator
301 /// (defined a the end of the file). For derived types, this returns the
302 /// types 'contained' in the derived type.
304 const Type *getContainedType(unsigned i) const {
305 assert(i < NumContainedTys && "Index out of range!");
306 return ContainedTys[i].get();
309 /// getNumContainedTypes - Return the number of types in the derived type.
311 unsigned getNumContainedTypes() const { return NumContainedTys; }
313 //===--------------------------------------------------------------------===//
314 // Static members exported by the Type class itself. Useful for getting
315 // instances of Type.
318 /// getPrimitiveType - Return a type based on an identifier.
319 static const Type *getPrimitiveType(TypeID IDNumber);
321 //===--------------------------------------------------------------------===//
322 // These are the builtin types that are always available...
324 static const Type *VoidTy, *LabelTy, *FloatTy, *DoubleTy;
325 static const Type *X86_FP80Ty, *FP128Ty, *PPC_FP128Ty;
326 static const IntegerType *Int1Ty, *Int8Ty, *Int16Ty, *Int32Ty, *Int64Ty;
328 /// Methods for support type inquiry through isa, cast, and dyn_cast:
329 static inline bool classof(const Type *) { return true; }
331 void addRef() const {
332 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
336 void dropRef() const {
337 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
338 assert(RefCount && "No objects are currently referencing this object!");
340 // If this is the last PATypeHolder using this object, and there are no
341 // PATypeHandles using it, the type is dead, delete it now.
342 if (--RefCount == 0 && AbstractTypeUsers.empty())
346 /// addAbstractTypeUser - Notify an abstract type that there is a new user of
347 /// it. This function is called primarily by the PATypeHandle class.
349 void addAbstractTypeUser(AbstractTypeUser *U) const {
350 assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!");
351 AbstractTypeUsers.push_back(U);
354 /// removeAbstractTypeUser - Notify an abstract type that a user of the class
355 /// no longer has a handle to the type. This function is called primarily by
356 /// the PATypeHandle class. When there are no users of the abstract type, it
357 /// is annihilated, because there is no way to get a reference to it ever
360 void removeAbstractTypeUser(AbstractTypeUser *U) const;
363 /// isSizedDerivedType - Derived types like structures and arrays are sized
364 /// iff all of the members of the type are sized as well. Since asking for
365 /// their size is relatively uncommon, move this operation out of line.
366 bool isSizedDerivedType() const;
368 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
369 virtual void typeBecameConcrete(const DerivedType *AbsTy);
372 // PromoteAbstractToConcrete - This is an internal method used to calculate
373 // change "Abstract" from true to false when types are refined.
374 void PromoteAbstractToConcrete();
375 friend class TypeMapBase;
378 //===----------------------------------------------------------------------===//
379 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
380 // These are defined here because they MUST be inlined, yet are dependent on
381 // the definition of the Type class.
383 inline void PATypeHandle::addUser() {
384 assert(Ty && "Type Handle has a null type!");
385 if (Ty->isAbstract())
386 Ty->addAbstractTypeUser(User);
388 inline void PATypeHandle::removeUser() {
389 if (Ty->isAbstract())
390 Ty->removeAbstractTypeUser(User);
393 // Define inline methods for PATypeHolder.
395 inline void PATypeHolder::addRef() {
396 assert(Ty && "Type Holder has a null type!");
397 if (Ty->isAbstract())
401 inline void PATypeHolder::dropRef() {
402 if (Ty->isAbstract())
407 //===----------------------------------------------------------------------===//
408 // Provide specializations of GraphTraits to be able to treat a type as a
409 // graph of sub types...
411 template <> struct GraphTraits<Type*> {
412 typedef Type NodeType;
413 typedef Type::subtype_iterator ChildIteratorType;
415 static inline NodeType *getEntryNode(Type *T) { return T; }
416 static inline ChildIteratorType child_begin(NodeType *N) {
417 return N->subtype_begin();
419 static inline ChildIteratorType child_end(NodeType *N) {
420 return N->subtype_end();
424 template <> struct GraphTraits<const Type*> {
425 typedef const Type NodeType;
426 typedef Type::subtype_iterator ChildIteratorType;
428 static inline NodeType *getEntryNode(const Type *T) { return T; }
429 static inline ChildIteratorType child_begin(NodeType *N) {
430 return N->subtype_begin();
432 static inline ChildIteratorType child_end(NodeType *N) {
433 return N->subtype_end();
437 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
438 return Ty.getTypeID() == Type::PointerTyID;
441 std::ostream &operator<<(std::ostream &OS, const Type &T);
443 } // End llvm namespace