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 UnionTyID, ///< 11: Unions
86 ArrayTyID, ///< 12: Arrays
87 PointerTyID, ///< 13: Pointers
88 OpaqueTyID, ///< 14: Opaque: type with unknown structure
89 VectorTyID, ///< 15: SIMD 'packed' format, or other vector type
91 NumTypeIDs, // Must remain as last defined ID
92 LastPrimitiveTyID = MetadataTyID,
93 FirstDerivedTyID = IntegerTyID
97 TypeID ID : 8; // The current base type of this type.
98 bool Abstract : 1; // True if type contains an OpaqueType
99 unsigned SubclassData : 23; //Space for subclasses to store data
101 /// RefCount - This counts the number of PATypeHolders that are pointing to
102 /// this type. When this number falls to zero, if the type is abstract and
103 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for
106 mutable unsigned RefCount;
108 /// Context - This refers to the LLVMContext in which this type was uniqued.
109 LLVMContext &Context;
110 friend class LLVMContextImpl;
112 const Type *getForwardedTypeInternal() const;
114 // Some Type instances are allocated as arrays, some aren't. So we provide
115 // this method to get the right kind of destruction for the type of Type.
116 void destroy() const; // const is a lie, this does "delete this"!
119 explicit Type(LLVMContext &C, TypeID id) :
120 ID(id), Abstract(false), SubclassData(0),
121 RefCount(0), Context(C),
122 ForwardType(0), NumContainedTys(0),
125 assert(AbstractTypeUsers.empty() && "Abstract types remain");
128 /// Types can become nonabstract later, if they are refined.
130 inline void setAbstract(bool Val) { Abstract = Val; }
132 unsigned getRefCount() const { return RefCount; }
134 unsigned getSubclassData() const { return SubclassData; }
135 void setSubclassData(unsigned val) { SubclassData = val; }
137 /// ForwardType - This field is used to implement the union find scheme for
138 /// abstract types. When types are refined to other types, this field is set
139 /// to the more refined type. Only abstract types can be forwarded.
140 mutable const Type *ForwardType;
143 /// AbstractTypeUsers - Implement a list of the users that need to be notified
144 /// if I am a type, and I get resolved into a more concrete type.
146 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers;
148 /// NumContainedTys - Keeps track of how many PATypeHandle instances there
149 /// are at the end of this type instance for the list of contained types. It
150 /// is the subclasses responsibility to set this up. Set to 0 if there are no
151 /// contained types in this type.
152 unsigned NumContainedTys;
154 /// ContainedTys - A pointer to the array of Types (PATypeHandle) contained
155 /// by this Type. For example, this includes the arguments of a function
156 /// type, the elements of a structure, the pointee of a pointer, the element
157 /// type of an array, etc. This pointer may be 0 for types that don't
158 /// contain other types (Integer, Double, Float). In general, the subclass
159 /// should arrange for space for the PATypeHandles to be included in the
160 /// allocation of the type object and set this pointer to the address of the
161 /// first element. This allows the Type class to manipulate the ContainedTys
162 /// without understanding the subclass's placement for this array. keeping
163 /// it here also allows the subtype_* members to be implemented MUCH more
164 /// efficiently, and dynamically very few types do not contain any elements.
165 PATypeHandle *ContainedTys;
168 void print(raw_ostream &O) const;
170 /// @brief Debugging support: print to stderr
173 /// @brief Debugging support: print to stderr (use type names from context
175 void dump(const Module *Context) const;
177 /// getContext - Fetch the LLVMContext in which this type was uniqued.
178 LLVMContext &getContext() const { return Context; }
180 //===--------------------------------------------------------------------===//
181 // Property accessors for dealing with types... Some of these virtual methods
182 // are defined in private classes defined in Type.cpp for primitive types.
185 /// getDescription - Return the string representation of the type.
186 std::string getDescription() const;
188 /// getTypeID - Return the type id for the type. This will return one
189 /// of the TypeID enum elements defined above.
191 inline TypeID getTypeID() const { return ID; }
193 /// isVoidTy - Return true if this is 'void'.
194 bool isVoidTy() const { return ID == VoidTyID; }
196 /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type.
197 bool isFloatTy() const { return ID == FloatTyID; }
199 /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type.
200 bool isDoubleTy() const { return ID == DoubleTyID; }
202 /// isX86_FP80Ty - Return true if this is x86 long double.
203 bool isX86_FP80Ty() const { return ID == X86_FP80TyID; }
205 /// isFP128Ty - Return true if this is 'fp128'.
206 bool isFP128Ty() const { return ID == FP128TyID; }
208 /// isPPC_FP128Ty - Return true if this is powerpc long double.
209 bool isPPC_FP128Ty() const { return ID == PPC_FP128TyID; }
211 /// isFloatingPointTy - Return true if this is one of the five floating point
213 bool isFloatingPointTy() const { return ID == FloatTyID || ID == DoubleTyID ||
214 ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; }
216 /// isFPOrFPVectorTy - Return true if this is a FP type or a vector of FP.
218 bool isFPOrFPVectorTy() const;
220 /// isLabelTy - Return true if this is 'label'.
221 bool isLabelTy() const { return ID == LabelTyID; }
223 /// isMetadataTy - Return true if this is 'metadata'.
224 bool isMetadataTy() const { return ID == MetadataTyID; }
226 /// isIntegerTy - True if this is an instance of IntegerType.
228 bool isIntegerTy() const { return ID == IntegerTyID; }
230 /// isIntegerTy - Return true if this is an IntegerType of the given width.
231 bool isIntegerTy(unsigned Bitwidth) const;
233 /// isIntOrIntVectorTy - Return true if this is an integer type or a vector of
236 bool isIntOrIntVectorTy() const;
238 /// isFunctionTy - True if this is an instance of FunctionType.
240 bool isFunctionTy() const { return ID == FunctionTyID; }
242 /// isStructTy - True if this is an instance of StructType.
244 bool isStructTy() const { return ID == StructTyID; }
246 /// isUnionTy - True if this is an instance of UnionType.
248 bool isUnionTy() const { return ID == UnionTyID; }
250 /// isArrayTy - True if this is an instance of ArrayType.
252 bool isArrayTy() const { return ID == ArrayTyID; }
254 /// isPointerTy - True if this is an instance of PointerType.
256 bool isPointerTy() const { return ID == PointerTyID; }
258 /// isOpaqueTy - True if this is an instance of OpaqueType.
260 bool isOpaqueTy() const { return ID == OpaqueTyID; }
262 /// isVectorTy - True if this is an instance of VectorType.
264 bool isVectorTy() const { return ID == VectorTyID; }
266 /// isAbstract - True if the type is either an Opaque type, or is a derived
267 /// type that includes an opaque type somewhere in it.
269 inline bool isAbstract() const { return Abstract; }
271 /// canLosslesslyBitCastTo - Return true if this type could be converted
272 /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts
273 /// are valid for types of the same size only where no re-interpretation of
274 /// the bits is done.
275 /// @brief Determine if this type could be losslessly bitcast to Ty
276 bool canLosslesslyBitCastTo(const Type *Ty) const;
279 /// Here are some useful little methods to query what type derived types are
280 /// Note that all other types can just compare to see if this == Type::xxxTy;
282 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
283 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
285 /// isFirstClassType - Return true if the type is "first class", meaning it
286 /// is a valid type for a Value.
288 inline bool isFirstClassType() const {
289 // There are more first-class kinds than non-first-class kinds, so a
290 // negative test is simpler than a positive one.
291 return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID;
294 /// isSingleValueType - Return true if the type is a valid type for a
295 /// virtual register in codegen. This includes all first-class types
296 /// except struct and array types.
298 inline bool isSingleValueType() const {
299 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
300 ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID;
303 /// isAggregateType - Return true if the type is an aggregate type. This
304 /// means it is valid as the first operand of an insertvalue or
305 /// extractvalue instruction. This includes struct and array types, but
306 /// does not include vector types.
308 inline bool isAggregateType() const {
309 return ID == StructTyID || ID == ArrayTyID || ID == UnionTyID;
312 /// isSized - Return true if it makes sense to take the size of this type. To
313 /// get the actual size for a particular target, it is reasonable to use the
314 /// TargetData subsystem to do this.
316 bool isSized() const {
317 // If it's a primitive, it is always sized.
318 if (ID == IntegerTyID || isFloatingPointTy() || ID == PointerTyID)
320 // If it is not something that can have a size (e.g. a function or label),
321 // it doesn't have a size.
322 if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID &&
325 // If it is something that can have a size and it's concrete, it definitely
326 // has a size, otherwise we have to try harder to decide.
327 return !isAbstract() || isSizedDerivedType();
330 /// getPrimitiveSizeInBits - Return the basic size of this type if it is a
331 /// primitive type. These are fixed by LLVM and are not target dependent.
332 /// This will return zero if the type does not have a size or is not a
335 /// Note that this may not reflect the size of memory allocated for an
336 /// instance of the type or the number of bytes that are written when an
337 /// instance of the type is stored to memory. The TargetData class provides
338 /// additional query functions to provide this information.
340 unsigned getPrimitiveSizeInBits() const;
342 /// getScalarSizeInBits - If this is a vector type, return the
343 /// getPrimitiveSizeInBits value for the element type. Otherwise return the
344 /// getPrimitiveSizeInBits value for this type.
345 unsigned getScalarSizeInBits() const;
347 /// getFPMantissaWidth - Return the width of the mantissa of this type. This
348 /// is only valid on floating point types. If the FP type does not
349 /// have a stable mantissa (e.g. ppc long double), this method returns -1.
350 int getFPMantissaWidth() const;
352 /// getForwardedType - Return the type that this type has been resolved to if
353 /// it has been resolved to anything. This is used to implement the
354 /// union-find algorithm for type resolution, and shouldn't be used by general
356 const Type *getForwardedType() const {
357 if (!ForwardType) return 0;
358 return getForwardedTypeInternal();
361 /// getVAArgsPromotedType - Return the type an argument of this type
362 /// will be promoted to if passed through a variable argument
364 const Type *getVAArgsPromotedType(LLVMContext &C) const;
366 /// getScalarType - If this is a vector type, return the element type,
367 /// otherwise return this.
368 const Type *getScalarType() const;
370 //===--------------------------------------------------------------------===//
371 // Type Iteration support
373 typedef PATypeHandle *subtype_iterator;
374 subtype_iterator subtype_begin() const { return ContainedTys; }
375 subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
377 /// getContainedType - This method is used to implement the type iterator
378 /// (defined a the end of the file). For derived types, this returns the
379 /// types 'contained' in the derived type.
381 const Type *getContainedType(unsigned i) const {
382 assert(i < NumContainedTys && "Index out of range!");
383 return ContainedTys[i].get();
386 /// getNumContainedTypes - Return the number of types in the derived type.
388 unsigned getNumContainedTypes() const { return NumContainedTys; }
390 //===--------------------------------------------------------------------===//
391 // Static members exported by the Type class itself. Useful for getting
392 // instances of Type.
395 /// getPrimitiveType - Return a type based on an identifier.
396 static const Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber);
398 //===--------------------------------------------------------------------===//
399 // These are the builtin types that are always available...
401 static const Type *getVoidTy(LLVMContext &C);
402 static const Type *getLabelTy(LLVMContext &C);
403 static const Type *getFloatTy(LLVMContext &C);
404 static const Type *getDoubleTy(LLVMContext &C);
405 static const Type *getMetadataTy(LLVMContext &C);
406 static const Type *getX86_FP80Ty(LLVMContext &C);
407 static const Type *getFP128Ty(LLVMContext &C);
408 static const Type *getPPC_FP128Ty(LLVMContext &C);
409 static const IntegerType *getInt1Ty(LLVMContext &C);
410 static const IntegerType *getInt8Ty(LLVMContext &C);
411 static const IntegerType *getInt16Ty(LLVMContext &C);
412 static const IntegerType *getInt32Ty(LLVMContext &C);
413 static const IntegerType *getInt64Ty(LLVMContext &C);
415 //===--------------------------------------------------------------------===//
416 // Convenience methods for getting pointer types with one of the above builtin
419 static const PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0);
420 static const PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0);
421 static const PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0);
422 static const PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0);
423 static const PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0);
424 static const PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0);
425 static const PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
426 static const PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0);
427 static const PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0);
428 static const PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0);
430 /// Methods for support type inquiry through isa, cast, and dyn_cast:
431 static inline bool classof(const Type *) { return true; }
433 void addRef() const {
434 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
438 void dropRef() const {
439 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
440 assert(RefCount && "No objects are currently referencing this object!");
442 // If this is the last PATypeHolder using this object, and there are no
443 // PATypeHandles using it, the type is dead, delete it now.
444 if (--RefCount == 0 && AbstractTypeUsers.empty())
448 /// addAbstractTypeUser - Notify an abstract type that there is a new user of
449 /// it. This function is called primarily by the PATypeHandle class.
451 void addAbstractTypeUser(AbstractTypeUser *U) const;
453 /// removeAbstractTypeUser - Notify an abstract type that a user of the class
454 /// no longer has a handle to the type. This function is called primarily by
455 /// the PATypeHandle class. When there are no users of the abstract type, it
456 /// is annihilated, because there is no way to get a reference to it ever
459 void removeAbstractTypeUser(AbstractTypeUser *U) const;
461 /// getPointerTo - Return a pointer to the current type. This is equivalent
462 /// to PointerType::get(Foo, AddrSpace).
463 const PointerType *getPointerTo(unsigned AddrSpace = 0) const;
466 /// isSizedDerivedType - Derived types like structures and arrays are sized
467 /// iff all of the members of the type are sized as well. Since asking for
468 /// their size is relatively uncommon, move this operation out of line.
469 bool isSizedDerivedType() const;
471 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
472 virtual void typeBecameConcrete(const DerivedType *AbsTy);
475 // PromoteAbstractToConcrete - This is an internal method used to calculate
476 // change "Abstract" from true to false when types are refined.
477 void PromoteAbstractToConcrete();
478 friend class TypeMapBase;
481 //===----------------------------------------------------------------------===//
482 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
483 // These are defined here because they MUST be inlined, yet are dependent on
484 // the definition of the Type class.
486 inline void PATypeHandle::addUser() {
487 assert(Ty && "Type Handle has a null type!");
488 if (Ty->isAbstract())
489 Ty->addAbstractTypeUser(User);
491 inline void PATypeHandle::removeUser() {
492 if (Ty->isAbstract())
493 Ty->removeAbstractTypeUser(User);
496 // Define inline methods for PATypeHolder.
498 /// get - This implements the forwarding part of the union-find algorithm for
499 /// abstract types. Before every access to the Type*, we check to see if the
500 /// type we are pointing to is forwarding to a new type. If so, we drop our
501 /// reference to the type.
503 inline Type* PATypeHolder::get() const {
504 const Type *NewTy = Ty->getForwardedType();
505 if (!NewTy) return const_cast<Type*>(Ty);
506 return *const_cast<PATypeHolder*>(this) = NewTy;
509 inline void PATypeHolder::addRef() {
510 assert(Ty && "Type Holder has a null type!");
511 if (Ty->isAbstract())
515 inline void PATypeHolder::dropRef() {
516 if (Ty->isAbstract())
521 //===----------------------------------------------------------------------===//
522 // Provide specializations of GraphTraits to be able to treat a type as a
523 // graph of sub types...
525 template <> struct GraphTraits<Type*> {
526 typedef Type NodeType;
527 typedef Type::subtype_iterator ChildIteratorType;
529 static inline NodeType *getEntryNode(Type *T) { return T; }
530 static inline ChildIteratorType child_begin(NodeType *N) {
531 return N->subtype_begin();
533 static inline ChildIteratorType child_end(NodeType *N) {
534 return N->subtype_end();
538 template <> struct GraphTraits<const Type*> {
539 typedef const Type NodeType;
540 typedef Type::subtype_iterator ChildIteratorType;
542 static inline NodeType *getEntryNode(const Type *T) { return T; }
543 static inline ChildIteratorType child_begin(NodeType *N) {
544 return N->subtype_begin();
546 static inline ChildIteratorType child_end(NodeType *N) {
547 return N->subtype_end();
551 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
552 return Ty.getTypeID() == Type::PointerTyID;
555 raw_ostream &operator<<(raw_ostream &OS, const Type &T);
557 } // End llvm namespace