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 //===----------------------------------------------------------------------===//
13 #include "llvm/AbstractTypeUser.h"
14 #include "llvm/Support/Casting.h"
15 #include "llvm/System/DataTypes.h"
16 #include "llvm/ADT/GraphTraits.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!
67 /// Also update LLVMTypeKind and LLVMGetTypeKind () in the C binding.
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 /// Context - This refers to the LLVMContext in which this type was uniqued.
108 LLVMContext &Context;
109 friend class LLVMContextImpl;
111 const Type *getForwardedTypeInternal() const;
113 // Some Type instances are allocated as arrays, some aren't. So we provide
114 // this method to get the right kind of destruction for the type of Type.
115 void destroy() const; // const is a lie, this does "delete this"!
118 explicit Type(LLVMContext &C, TypeID id) :
119 ID(id), Abstract(false), SubclassData(0),
120 RefCount(0), Context(C),
121 ForwardType(0), NumContainedTys(0),
124 assert(AbstractTypeUsers.empty() && "Abstract types remain");
127 /// Types can become nonabstract later, if they are refined.
129 inline void setAbstract(bool Val) { Abstract = Val; }
131 unsigned getRefCount() const { return RefCount; }
133 unsigned getSubclassData() const { return SubclassData; }
134 void setSubclassData(unsigned val) { SubclassData = val; }
136 /// ForwardType - This field is used to implement the union find scheme for
137 /// abstract types. When types are refined to other types, this field is set
138 /// to the more refined type. Only abstract types can be forwarded.
139 mutable const Type *ForwardType;
142 /// AbstractTypeUsers - Implement a list of the users that need to be notified
143 /// if I am a type, and I get resolved into a more concrete type.
145 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers;
147 /// NumContainedTys - Keeps track of how many PATypeHandle instances there
148 /// are at the end of this type instance for the list of contained types. It
149 /// is the subclasses responsibility to set this up. Set to 0 if there are no
150 /// contained types in this type.
151 unsigned NumContainedTys;
153 /// ContainedTys - A pointer to the array of Types (PATypeHandle) contained
154 /// by this Type. For example, this includes the arguments of a function
155 /// type, the elements of a structure, the pointee of a pointer, the element
156 /// type of an array, etc. This pointer may be 0 for types that don't
157 /// contain other types (Integer, Double, Float). In general, the subclass
158 /// should arrange for space for the PATypeHandles to be included in the
159 /// allocation of the type object and set this pointer to the address of the
160 /// first element. This allows the Type class to manipulate the ContainedTys
161 /// without understanding the subclass's placement for this array. keeping
162 /// it here also allows the subtype_* members to be implemented MUCH more
163 /// efficiently, and dynamically very few types do not contain any elements.
164 PATypeHandle *ContainedTys;
167 void print(raw_ostream &O) const;
169 /// @brief Debugging support: print to stderr
172 /// @brief Debugging support: print to stderr (use type names from context
174 void dump(const Module *Context) const;
176 /// getContext - Fetch the LLVMContext in which this type was uniqued.
177 LLVMContext &getContext() const { return Context; }
179 //===--------------------------------------------------------------------===//
180 // Property accessors for dealing with types... Some of these virtual methods
181 // are defined in private classes defined in Type.cpp for primitive types.
184 /// getTypeID - Return the type id for the type. This will return one
185 /// of the TypeID enum elements defined above.
187 inline TypeID getTypeID() const { return ID; }
189 /// isVoidTy - Return true if this is 'void'.
190 bool isVoidTy() const { return ID == VoidTyID; }
192 /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type.
193 bool isFloatTy() const { return ID == FloatTyID; }
195 /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type.
196 bool isDoubleTy() const { return ID == DoubleTyID; }
198 /// isX86_FP80Ty - Return true if this is x86 long double.
199 bool isX86_FP80Ty() const { return ID == X86_FP80TyID; }
201 /// isFP128Ty - Return true if this is 'fp128'.
202 bool isFP128Ty() const { return ID == FP128TyID; }
204 /// isPPC_FP128Ty - Return true if this is powerpc long double.
205 bool isPPC_FP128Ty() const { return ID == PPC_FP128TyID; }
207 /// isLabelTy - Return true if this is 'label'.
208 bool isLabelTy() const { return ID == LabelTyID; }
210 /// isMetadataTy - Return true if this is 'metadata'.
211 bool isMetadataTy() const { return ID == MetadataTyID; }
213 /// getDescription - Return the string representation of the type.
214 std::string getDescription() const;
216 /// isInteger - True if this is an instance of IntegerType.
218 bool isInteger() const { return ID == IntegerTyID; }
220 /// isInteger - Return true if this is an IntegerType of the specified width.
221 bool isInteger(unsigned Bitwidth) const;
223 /// isIntOrIntVector - Return true if this is an integer type or a vector of
226 bool isIntOrIntVector() const;
228 /// isFloatingPoint - Return true if this is one of the five floating point
230 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID ||
231 ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; }
233 /// isFPOrFPVector - Return true if this is a FP type or a vector of FP types.
235 bool isFPOrFPVector() const;
237 /// isAbstract - True if the type is either an Opaque type, or is a derived
238 /// type that includes an opaque type somewhere in it.
240 inline bool isAbstract() const { return Abstract; }
242 /// canLosslesslyBitCastTo - Return true if this type could be converted
243 /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts
244 /// are valid for types of the same size only where no re-interpretation of
245 /// the bits is done.
246 /// @brief Determine if this type could be losslessly bitcast to Ty
247 bool canLosslesslyBitCastTo(const Type *Ty) const;
250 /// Here are some useful little methods to query what type derived types are
251 /// Note that all other types can just compare to see if this == Type::xxxTy;
253 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
254 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
256 /// isFirstClassType - Return true if the type is "first class", meaning it
257 /// is a valid type for a Value.
259 inline bool isFirstClassType() const {
260 // There are more first-class kinds than non-first-class kinds, so a
261 // negative test is simpler than a positive one.
262 return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID;
265 /// isSingleValueType - Return true if the type is a valid type for a
266 /// virtual register in codegen. This includes all first-class types
267 /// except struct and array types.
269 inline bool isSingleValueType() const {
270 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
271 ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID;
274 /// isAggregateType - Return true if the type is an aggregate type. This
275 /// means it is valid as the first operand of an insertvalue or
276 /// extractvalue instruction. This includes struct and array types, but
277 /// does not include vector types.
279 inline bool isAggregateType() const {
280 return ID == StructTyID || ID == ArrayTyID;
283 /// isSized - Return true if it makes sense to take the size of this type. To
284 /// get the actual size for a particular target, it is reasonable to use the
285 /// TargetData subsystem to do this.
287 bool isSized() const {
288 // If it's a primitive, it is always sized.
289 if (ID == IntegerTyID || isFloatingPoint() || ID == PointerTyID)
291 // If it is not something that can have a size (e.g. a function or label),
292 // it doesn't have a size.
293 if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID)
295 // If it is something that can have a size and it's concrete, it definitely
296 // has a size, otherwise we have to try harder to decide.
297 return !isAbstract() || isSizedDerivedType();
300 /// getPrimitiveSizeInBits - Return the basic size of this type if it is a
301 /// primitive type. These are fixed by LLVM and are not target dependent.
302 /// This will return zero if the type does not have a size or is not a
305 /// Note that this may not reflect the size of memory allocated for an
306 /// instance of the type or the number of bytes that are written when an
307 /// instance of the type is stored to memory. The TargetData class provides
308 /// additional query functions to provide this information.
310 unsigned getPrimitiveSizeInBits() const;
312 /// getScalarSizeInBits - If this is a vector type, return the
313 /// getPrimitiveSizeInBits value for the element type. Otherwise return the
314 /// getPrimitiveSizeInBits value for this type.
315 unsigned getScalarSizeInBits() const;
317 /// getFPMantissaWidth - Return the width of the mantissa of this type. This
318 /// is only valid on floating point types. If the FP type does not
319 /// have a stable mantissa (e.g. ppc long double), this method returns -1.
320 int getFPMantissaWidth() const;
322 /// getForwardedType - Return the type that this type has been resolved to if
323 /// it has been resolved to anything. This is used to implement the
324 /// union-find algorithm for type resolution, and shouldn't be used by general
326 const Type *getForwardedType() const {
327 if (!ForwardType) return 0;
328 return getForwardedTypeInternal();
331 /// getVAArgsPromotedType - Return the type an argument of this type
332 /// will be promoted to if passed through a variable argument
334 const Type *getVAArgsPromotedType(LLVMContext &C) const;
336 /// getScalarType - If this is a vector type, return the element type,
337 /// otherwise return this.
338 const Type *getScalarType() const;
340 //===--------------------------------------------------------------------===//
341 // Type Iteration support
343 typedef PATypeHandle *subtype_iterator;
344 subtype_iterator subtype_begin() const { return ContainedTys; }
345 subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
347 /// getContainedType - This method is used to implement the type iterator
348 /// (defined a the end of the file). For derived types, this returns the
349 /// types 'contained' in the derived type.
351 const Type *getContainedType(unsigned i) const {
352 assert(i < NumContainedTys && "Index out of range!");
353 return ContainedTys[i].get();
356 /// getNumContainedTypes - Return the number of types in the derived type.
358 unsigned getNumContainedTypes() const { return NumContainedTys; }
360 //===--------------------------------------------------------------------===//
361 // Static members exported by the Type class itself. Useful for getting
362 // instances of Type.
365 /// getPrimitiveType - Return a type based on an identifier.
366 static const Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber);
368 //===--------------------------------------------------------------------===//
369 // These are the builtin types that are always available...
371 static const Type *getVoidTy(LLVMContext &C);
372 static const Type *getLabelTy(LLVMContext &C);
373 static const Type *getFloatTy(LLVMContext &C);
374 static const Type *getDoubleTy(LLVMContext &C);
375 static const Type *getMetadataTy(LLVMContext &C);
376 static const Type *getX86_FP80Ty(LLVMContext &C);
377 static const Type *getFP128Ty(LLVMContext &C);
378 static const Type *getPPC_FP128Ty(LLVMContext &C);
379 static const IntegerType *getInt1Ty(LLVMContext &C);
380 static const IntegerType *getInt8Ty(LLVMContext &C);
381 static const IntegerType *getInt16Ty(LLVMContext &C);
382 static const IntegerType *getInt32Ty(LLVMContext &C);
383 static const IntegerType *getInt64Ty(LLVMContext &C);
385 //===--------------------------------------------------------------------===//
386 // Convenience methods for getting pointer types with one of the above builtin
389 static const PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0);
390 static const PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0);
391 static const PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0);
392 static const PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0);
393 static const PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0);
394 static const PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0);
395 static const PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
396 static const PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0);
397 static const PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0);
398 static const PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0);
400 /// Methods for support type inquiry through isa, cast, and dyn_cast:
401 static inline bool classof(const Type *) { return true; }
403 void addRef() const {
404 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
408 void dropRef() const {
409 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
410 assert(RefCount && "No objects are currently referencing this object!");
412 // If this is the last PATypeHolder using this object, and there are no
413 // PATypeHandles using it, the type is dead, delete it now.
414 if (--RefCount == 0 && AbstractTypeUsers.empty())
418 /// addAbstractTypeUser - Notify an abstract type that there is a new user of
419 /// it. This function is called primarily by the PATypeHandle class.
421 void addAbstractTypeUser(AbstractTypeUser *U) const;
423 /// removeAbstractTypeUser - Notify an abstract type that a user of the class
424 /// no longer has a handle to the type. This function is called primarily by
425 /// the PATypeHandle class. When there are no users of the abstract type, it
426 /// is annihilated, because there is no way to get a reference to it ever
429 void removeAbstractTypeUser(AbstractTypeUser *U) const;
431 /// getPointerTo - Return a pointer to the current type. This is equivalent
432 /// to PointerType::get(Foo, AddrSpace).
433 const PointerType *getPointerTo(unsigned AddrSpace = 0) const;
436 /// isSizedDerivedType - Derived types like structures and arrays are sized
437 /// iff all of the members of the type are sized as well. Since asking for
438 /// their size is relatively uncommon, move this operation out of line.
439 bool isSizedDerivedType() const;
441 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
442 virtual void typeBecameConcrete(const DerivedType *AbsTy);
445 // PromoteAbstractToConcrete - This is an internal method used to calculate
446 // change "Abstract" from true to false when types are refined.
447 void PromoteAbstractToConcrete();
448 friend class TypeMapBase;
451 //===----------------------------------------------------------------------===//
452 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
453 // These are defined here because they MUST be inlined, yet are dependent on
454 // the definition of the Type class.
456 inline void PATypeHandle::addUser() {
457 assert(Ty && "Type Handle has a null type!");
458 if (Ty->isAbstract())
459 Ty->addAbstractTypeUser(User);
461 inline void PATypeHandle::removeUser() {
462 if (Ty->isAbstract())
463 Ty->removeAbstractTypeUser(User);
466 // Define inline methods for PATypeHolder.
468 /// get - This implements the forwarding part of the union-find algorithm for
469 /// abstract types. Before every access to the Type*, we check to see if the
470 /// type we are pointing to is forwarding to a new type. If so, we drop our
471 /// reference to the type.
473 inline Type* PATypeHolder::get() const {
474 const Type *NewTy = Ty->getForwardedType();
475 if (!NewTy) return const_cast<Type*>(Ty);
476 return *const_cast<PATypeHolder*>(this) = NewTy;
479 inline void PATypeHolder::addRef() {
480 assert(Ty && "Type Holder has a null type!");
481 if (Ty->isAbstract())
485 inline void PATypeHolder::dropRef() {
486 if (Ty->isAbstract())
491 //===----------------------------------------------------------------------===//
492 // Provide specializations of GraphTraits to be able to treat a type as a
493 // graph of sub types...
495 template <> struct GraphTraits<Type*> {
496 typedef Type NodeType;
497 typedef Type::subtype_iterator ChildIteratorType;
499 static inline NodeType *getEntryNode(Type *T) { return T; }
500 static inline ChildIteratorType child_begin(NodeType *N) {
501 return N->subtype_begin();
503 static inline ChildIteratorType child_end(NodeType *N) {
504 return N->subtype_end();
508 template <> struct GraphTraits<const Type*> {
509 typedef const Type NodeType;
510 typedef Type::subtype_iterator ChildIteratorType;
512 static inline NodeType *getEntryNode(const Type *T) { return T; }
513 static inline ChildIteratorType child_begin(NodeType *N) {
514 return N->subtype_begin();
516 static inline ChildIteratorType child_end(NodeType *N) {
517 return N->subtype_end();
521 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
522 return Ty.getTypeID() == Type::PointerTyID;
525 raw_ostream &operator<<(raw_ostream &OS, const Type &T);
527 } // End llvm namespace