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/ADT/GraphTraits.h"
18 #include "llvm/ADT/iterator.h"
31 /// This file contains the declaration of the Type class. For more "Type" type
32 /// stuff, look in DerivedTypes.h.
34 /// The instances of the Type class are immutable: once they are created,
35 /// they are never changed. Also note that only one instance of a particular
36 /// type is ever created. Thus seeing if two types are equal is a matter of
37 /// doing a trivial pointer comparison. To enforce that no two equal instances
38 /// are created, Type instances can only be created via static factory methods
39 /// in class Type and in derived classes.
41 /// Once allocated, Types are never free'd, unless they are an abstract type
42 /// that is resolved to a more concrete type.
44 /// Types themself don't have a name, and can be named either by:
45 /// - using SymbolTable instance, typically from some Module,
46 /// - using convenience methods in the Module class (which uses module's
49 /// Opaque types are simple derived types with no state. There may be many
50 /// different Opaque type objects floating around, but two are only considered
51 /// identical if they are pointer equals of each other. This allows us to have
52 /// two opaque types that end up resolving to different concrete types later.
54 /// Opaque types are also kinda weird and scary and different because they have
55 /// to keep a list of uses of the type. When, through linking, parsing, or
56 /// bitcode reading, they become resolved, they need to find and update all
57 /// users of the unknown type, causing them to reference a new, more concrete
58 /// type. Opaque types are deleted when their use list dwindles to zero users.
60 /// @brief Root of type hierarchy
61 class Type : public AbstractTypeUser {
63 //===-------------------------------------------------------------------===//
64 /// Definitions of all of the base types for the Type system. Based on this
65 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
66 /// Note: If you add an element to this, you need to add an element to the
67 /// Type::getPrimitiveType function, or else things will break!
70 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date
71 VoidTyID = 0, ///< 0: type with no size
72 FloatTyID, ///< 1: 32 bit floating point type
73 DoubleTyID, ///< 2: 64 bit floating point type
74 X86_FP80TyID, ///< 3: 80 bit floating point type (X87)
75 FP128TyID, ///< 4: 128 bit floating point type (112-bit mantissa)
76 PPC_FP128TyID, ///< 5: 128 bit floating point type (two 64-bits)
77 LabelTyID, ///< 6: Labels
78 MetadataTyID, ///< 7: Metadata
80 // Derived types... see DerivedTypes.h file...
81 // Make sure FirstDerivedTyID stays up to date!!!
82 IntegerTyID, ///< 8: Arbitrary bit width integers
83 FunctionTyID, ///< 9: Functions
84 StructTyID, ///< 10: Structures
85 ArrayTyID, ///< 11: Arrays
86 PointerTyID, ///< 12: Pointers
87 OpaqueTyID, ///< 13: Opaque: type with unknown structure
88 VectorTyID, ///< 14: SIMD 'packed' format, or other vector type
90 NumTypeIDs, // Must remain as last defined ID
91 LastPrimitiveTyID = LabelTyID,
92 FirstDerivedTyID = IntegerTyID
96 TypeID ID : 8; // The current base type of this type.
97 bool Abstract : 1; // True if type contains an OpaqueType
98 unsigned SubclassData : 23; //Space for subclasses to store data
100 /// RefCount - This counts the number of PATypeHolders that are pointing to
101 /// this type. When this number falls to zero, if the type is abstract and
102 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for
105 mutable unsigned RefCount;
107 const Type *getForwardedTypeInternal() const;
109 // Some Type instances are allocated as arrays, some aren't. So we provide
110 // this method to get the right kind of destruction for the type of Type.
111 void destroy() const; // const is a lie, this does "delete this"!
114 explicit Type(TypeID id) : ID(id), Abstract(false), SubclassData(0),
115 RefCount(0), ForwardType(0), NumContainedTys(0),
118 assert(AbstractTypeUsers.empty() && "Abstract types remain");
121 /// Types can become nonabstract later, if they are refined.
123 inline void setAbstract(bool Val) { Abstract = Val; }
125 unsigned getRefCount() const { return RefCount; }
127 unsigned getSubclassData() const { return SubclassData; }
128 void setSubclassData(unsigned val) { SubclassData = val; }
130 /// ForwardType - This field is used to implement the union find scheme for
131 /// abstract types. When types are refined to other types, this field is set
132 /// to the more refined type. Only abstract types can be forwarded.
133 mutable const Type *ForwardType;
136 /// AbstractTypeUsers - Implement a list of the users that need to be notified
137 /// if I am a type, and I get resolved into a more concrete type.
139 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers;
141 /// NumContainedTys - Keeps track of how many PATypeHandle instances there
142 /// are at the end of this type instance for the list of contained types. It
143 /// is the subclasses responsibility to set this up. Set to 0 if there are no
144 /// contained types in this type.
145 unsigned NumContainedTys;
147 /// ContainedTys - A pointer to the array of Types (PATypeHandle) contained
148 /// by this Type. For example, this includes the arguments of a function
149 /// type, the elements of a structure, the pointee of a pointer, the element
150 /// type of an array, etc. This pointer may be 0 for types that don't
151 /// contain other types (Integer, Double, Float). In general, the subclass
152 /// should arrange for space for the PATypeHandles to be included in the
153 /// allocation of the type object and set this pointer to the address of the
154 /// first element. This allows the Type class to manipulate the ContainedTys
155 /// without understanding the subclass's placement for this array. keeping
156 /// it here also allows the subtype_* members to be implemented MUCH more
157 /// efficiently, and dynamically very few types do not contain any elements.
158 PATypeHandle *ContainedTys;
161 void print(raw_ostream &O) const;
162 void print(std::ostream &O) const;
164 /// @brief Debugging support: print to stderr
167 /// @brief Debugging support: print to stderr (use type names from context
169 void dump(const Module *Context) const;
171 //===--------------------------------------------------------------------===//
172 // Property accessors for dealing with types... Some of these virtual methods
173 // are defined in private classes defined in Type.cpp for primitive types.
176 /// getTypeID - Return the type id for the type. This will return one
177 /// of the TypeID enum elements defined above.
179 inline TypeID getTypeID() const { return ID; }
181 /// getDescription - Return the string representation of the type.
182 std::string getDescription() const;
184 /// isInteger - True if this is an instance of IntegerType.
186 bool isInteger() const { return ID == IntegerTyID; }
188 /// isIntOrIntVector - Return true if this is an integer type or a vector of
191 bool isIntOrIntVector() const;
193 /// isFloatingPoint - Return true if this is one of the two floating point
195 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID ||
196 ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; }
198 /// isFPOrFPVector - Return true if this is a FP type or a vector of FP types.
200 bool isFPOrFPVector() const;
202 /// isAbstract - True if the type is either an Opaque type, or is a derived
203 /// type that includes an opaque type somewhere in it.
205 inline bool isAbstract() const { return Abstract; }
207 /// canLosslesslyBitCastTo - Return true if this type could be converted
208 /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts
209 /// are valid for types of the same size only where no re-interpretation of
210 /// the bits is done.
211 /// @brief Determine if this type could be losslessly bitcast to Ty
212 bool canLosslesslyBitCastTo(const Type *Ty) const;
215 /// Here are some useful little methods to query what type derived types are
216 /// Note that all other types can just compare to see if this == Type::xxxTy;
218 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
219 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
221 /// isFirstClassType - Return true if the type is "first class", meaning it
222 /// is a valid type for a Value.
224 inline bool isFirstClassType() const {
225 // There are more first-class kinds than non-first-class kinds, so a
226 // negative test is simpler than a positive one.
227 return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID;
230 /// isSingleValueType - Return true if the type is a valid type for a
231 /// virtual register in codegen. This includes all first-class types
232 /// except struct and array types.
234 inline bool isSingleValueType() const {
235 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
236 ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID;
239 /// isAggregateType - Return true if the type is an aggregate type. This
240 /// means it is valid as the first operand of an insertvalue or
241 /// extractvalue instruction. This includes struct and array types, but
242 /// does not include vector types.
244 inline bool isAggregateType() const {
245 return ID == StructTyID || ID == ArrayTyID;
248 /// isSized - Return true if it makes sense to take the size of this type. To
249 /// get the actual size for a particular target, it is reasonable to use the
250 /// TargetData subsystem to do this.
252 bool isSized() const {
253 // If it's a primitive, it is always sized.
254 if (ID == IntegerTyID || isFloatingPoint() || ID == PointerTyID)
256 // If it is not something that can have a size (e.g. a function or label),
257 // it doesn't have a size.
258 if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID)
260 // If it is something that can have a size and it's concrete, it definitely
261 // has a size, otherwise we have to try harder to decide.
262 return !isAbstract() || isSizedDerivedType();
265 /// getPrimitiveSizeInBits - Return the basic size of this type if it is a
266 /// primitive type. These are fixed by LLVM and are not target dependent.
267 /// This will return zero if the type does not have a size or is not a
270 unsigned getPrimitiveSizeInBits() const;
272 /// getFPMantissaWidth - Return the width of the mantissa of this type. This
273 /// is only valid on scalar floating point types. If the FP type does not
274 /// have a stable mantissa (e.g. ppc long double), this method returns -1.
275 int getFPMantissaWidth() const {
276 assert(isFloatingPoint() && "Not a floating point type!");
277 if (ID == FloatTyID) return 24;
278 if (ID == DoubleTyID) return 53;
279 if (ID == X86_FP80TyID) return 64;
280 if (ID == FP128TyID) return 113;
281 assert(ID == PPC_FP128TyID && "unknown fp type");
285 /// getForwardedType - Return the type that this type has been resolved to if
286 /// it has been resolved to anything. This is used to implement the
287 /// union-find algorithm for type resolution, and shouldn't be used by general
289 const Type *getForwardedType() const {
290 if (!ForwardType) return 0;
291 return getForwardedTypeInternal();
294 /// getVAArgsPromotedType - Return the type an argument of this type
295 /// will be promoted to if passed through a variable argument
297 const Type *getVAArgsPromotedType() const;
299 //===--------------------------------------------------------------------===//
300 // Type Iteration support
302 typedef PATypeHandle *subtype_iterator;
303 subtype_iterator subtype_begin() const { return ContainedTys; }
304 subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
306 /// getContainedType - This method is used to implement the type iterator
307 /// (defined a the end of the file). For derived types, this returns the
308 /// types 'contained' in the derived type.
310 const Type *getContainedType(unsigned i) const {
311 assert(i < NumContainedTys && "Index out of range!");
312 return ContainedTys[i].get();
315 /// getNumContainedTypes - Return the number of types in the derived type.
317 unsigned getNumContainedTypes() const { return NumContainedTys; }
319 //===--------------------------------------------------------------------===//
320 // Static members exported by the Type class itself. Useful for getting
321 // instances of Type.
324 /// getPrimitiveType - Return a type based on an identifier.
325 static const Type *getPrimitiveType(TypeID IDNumber);
327 //===--------------------------------------------------------------------===//
328 // These are the builtin types that are always available...
330 static const Type *VoidTy, *LabelTy, *FloatTy, *DoubleTy, *MetadataTy;
331 static const Type *X86_FP80Ty, *FP128Ty, *PPC_FP128Ty;
332 static const IntegerType *Int1Ty, *Int8Ty, *Int16Ty, *Int32Ty, *Int64Ty;
334 /// Methods for support type inquiry through isa, cast, and dyn_cast:
335 static inline bool classof(const Type *) { return true; }
337 void addRef() const {
338 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
342 void dropRef() const {
343 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
344 assert(RefCount && "No objects are currently referencing this object!");
346 // If this is the last PATypeHolder using this object, and there are no
347 // PATypeHandles using it, the type is dead, delete it now.
348 if (--RefCount == 0 && AbstractTypeUsers.empty())
352 /// addAbstractTypeUser - Notify an abstract type that there is a new user of
353 /// it. This function is called primarily by the PATypeHandle class.
355 void addAbstractTypeUser(AbstractTypeUser *U) const {
356 assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!");
357 AbstractTypeUsers.push_back(U);
360 /// removeAbstractTypeUser - Notify an abstract type that a user of the class
361 /// no longer has a handle to the type. This function is called primarily by
362 /// the PATypeHandle class. When there are no users of the abstract type, it
363 /// is annihilated, because there is no way to get a reference to it ever
366 void removeAbstractTypeUser(AbstractTypeUser *U) const;
368 /// getPointerTo - Return a pointer to the current type. This is equivalent
369 /// to PointerType::get(Foo, AddrSpace).
370 PointerType *getPointerTo(unsigned AddrSpace = 0) const;
373 /// isSizedDerivedType - Derived types like structures and arrays are sized
374 /// iff all of the members of the type are sized as well. Since asking for
375 /// their size is relatively uncommon, move this operation out of line.
376 bool isSizedDerivedType() const;
378 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
379 virtual void typeBecameConcrete(const DerivedType *AbsTy);
382 // PromoteAbstractToConcrete - This is an internal method used to calculate
383 // change "Abstract" from true to false when types are refined.
384 void PromoteAbstractToConcrete();
385 friend class TypeMapBase;
388 //===----------------------------------------------------------------------===//
389 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
390 // These are defined here because they MUST be inlined, yet are dependent on
391 // the definition of the Type class.
393 inline void PATypeHandle::addUser() {
394 assert(Ty && "Type Handle has a null type!");
395 if (Ty->isAbstract())
396 Ty->addAbstractTypeUser(User);
398 inline void PATypeHandle::removeUser() {
399 if (Ty->isAbstract())
400 Ty->removeAbstractTypeUser(User);
403 // Define inline methods for PATypeHolder.
405 /// get - This implements the forwarding part of the union-find algorithm for
406 /// abstract types. Before every access to the Type*, we check to see if the
407 /// type we are pointing to is forwarding to a new type. If so, we drop our
408 /// reference to the type.
410 inline Type* PATypeHolder::get() const {
411 const Type *NewTy = Ty->getForwardedType();
412 if (!NewTy) return const_cast<Type*>(Ty);
413 return *const_cast<PATypeHolder*>(this) = NewTy;
416 inline void PATypeHolder::addRef() {
417 assert(Ty && "Type Holder has a null type!");
418 if (Ty->isAbstract())
422 inline void PATypeHolder::dropRef() {
423 if (Ty->isAbstract())
428 //===----------------------------------------------------------------------===//
429 // Provide specializations of GraphTraits to be able to treat a type as a
430 // graph of sub types...
432 template <> struct GraphTraits<Type*> {
433 typedef Type NodeType;
434 typedef Type::subtype_iterator ChildIteratorType;
436 static inline NodeType *getEntryNode(Type *T) { return T; }
437 static inline ChildIteratorType child_begin(NodeType *N) {
438 return N->subtype_begin();
440 static inline ChildIteratorType child_end(NodeType *N) {
441 return N->subtype_end();
445 template <> struct GraphTraits<const Type*> {
446 typedef const Type NodeType;
447 typedef Type::subtype_iterator ChildIteratorType;
449 static inline NodeType *getEntryNode(const Type *T) { return T; }
450 static inline ChildIteratorType child_begin(NodeType *N) {
451 return N->subtype_begin();
453 static inline ChildIteratorType child_end(NodeType *N) {
454 return N->subtype_end();
458 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
459 return Ty.getTypeID() == Type::PointerTyID;
462 std::ostream &operator<<(std::ostream &OS, const Type &T);
463 raw_ostream &operator<<(raw_ostream &OS, const Type &T);
465 } // End llvm namespace