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 //===----------------------------------------------------------------------===//
10 // This file contains the declaration of the Type class. For more "Type"
11 // stuff, look in DerivedTypes.h.
13 //===----------------------------------------------------------------------===//
18 #include "llvm/AbstractTypeUser.h"
19 #include "llvm/Support/Casting.h"
31 template<class GraphType> struct GraphTraits;
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, PowerPC)
77 LabelTyID, ///< 6: Labels
78 MetadataTyID, ///< 7: Metadata
79 X86_MMXTyID, ///< 8: MMX vectors (64 bits, X86 specific)
81 // Derived types... see DerivedTypes.h file.
82 // Make sure FirstDerivedTyID stays up to date!
83 IntegerTyID, ///< 9: Arbitrary bit width integers
84 FunctionTyID, ///< 10: Functions
85 StructTyID, ///< 11: Structures
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 = X86_MMXTyID,
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 // When the last reference to a forwarded type is removed, it is destroyed.
115 void destroy() const;
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 // Accessors for working with types.
183 /// getTypeID - Return the type id for the type. This will return one
184 /// of the TypeID enum elements defined above.
186 TypeID getTypeID() const { return ID; }
188 /// isVoidTy - Return true if this is 'void'.
189 bool isVoidTy() const { return ID == VoidTyID; }
191 /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type.
192 bool isFloatTy() const { return ID == FloatTyID; }
194 /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type.
195 bool isDoubleTy() const { return ID == DoubleTyID; }
197 /// isX86_FP80Ty - Return true if this is x86 long double.
198 bool isX86_FP80Ty() const { return ID == X86_FP80TyID; }
200 /// isFP128Ty - Return true if this is 'fp128'.
201 bool isFP128Ty() const { return ID == FP128TyID; }
203 /// isPPC_FP128Ty - Return true if this is powerpc long double.
204 bool isPPC_FP128Ty() const { return ID == PPC_FP128TyID; }
206 /// isFloatingPointTy - Return true if this is one of the five floating point
208 bool isFloatingPointTy() const { return ID == FloatTyID || ID == DoubleTyID ||
209 ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; }
211 /// isX86_MMXTy - Return true if this is X86 MMX.
212 bool isX86_MMXTy() const { return ID == X86_MMXTyID; }
214 /// isFPOrFPVectorTy - Return true if this is a FP type or a vector of FP.
216 bool isFPOrFPVectorTy() const;
218 /// isLabelTy - Return true if this is 'label'.
219 bool isLabelTy() const { return ID == LabelTyID; }
221 /// isMetadataTy - Return true if this is 'metadata'.
222 bool isMetadataTy() const { return ID == MetadataTyID; }
224 /// isIntegerTy - True if this is an instance of IntegerType.
226 bool isIntegerTy() const { return ID == IntegerTyID; }
228 /// isIntegerTy - Return true if this is an IntegerType of the given width.
229 bool isIntegerTy(unsigned Bitwidth) const;
231 /// isIntOrIntVectorTy - Return true if this is an integer type or a vector of
234 bool isIntOrIntVectorTy() const;
236 /// isFunctionTy - True if this is an instance of FunctionType.
238 bool isFunctionTy() const { return ID == FunctionTyID; }
240 /// isStructTy - True if this is an instance of StructType.
242 bool isStructTy() const { return ID == StructTyID; }
244 /// isArrayTy - True if this is an instance of ArrayType.
246 bool isArrayTy() const { return ID == ArrayTyID; }
248 /// isPointerTy - True if this is an instance of PointerType.
250 bool isPointerTy() const { return ID == PointerTyID; }
252 /// isOpaqueTy - True if this is an instance of OpaqueType.
254 bool isOpaqueTy() const { return ID == OpaqueTyID; }
256 /// isVectorTy - True if this is an instance of VectorType.
258 bool isVectorTy() const { return ID == VectorTyID; }
260 /// isAbstract - True if the type is either an Opaque type, or is a derived
261 /// type that includes an opaque type somewhere in it.
263 inline bool isAbstract() const { return Abstract; }
265 /// canLosslesslyBitCastTo - Return true if this type could be converted
266 /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts
267 /// are valid for types of the same size only where no re-interpretation of
268 /// the bits is done.
269 /// @brief Determine if this type could be losslessly bitcast to Ty
270 bool canLosslesslyBitCastTo(const Type *Ty) const;
272 /// isEmptyTy - Return true if this type is empty, that is, it has no
273 /// elements or all its elements are empty.
274 bool isEmptyTy() const;
276 /// Here are some useful little methods to query what type derived types are
277 /// Note that all other types can just compare to see if this == Type::xxxTy;
279 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
280 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
282 /// isFirstClassType - Return true if the type is "first class", meaning it
283 /// is a valid type for a Value.
285 inline bool isFirstClassType() const {
286 // There are more first-class kinds than non-first-class kinds, so a
287 // negative test is simpler than a positive one.
288 return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID;
291 /// isSingleValueType - Return true if the type is a valid type for a
292 /// virtual register in codegen. This includes all first-class types
293 /// except struct and array types.
295 inline bool isSingleValueType() const {
296 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
297 ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID;
300 /// isAggregateType - Return true if the type is an aggregate type. This
301 /// means it is valid as the first operand of an insertvalue or
302 /// extractvalue instruction. This includes struct and array types, but
303 /// does not include vector types.
305 inline bool isAggregateType() const {
306 return ID == StructTyID || ID == ArrayTyID;
309 /// isSized - Return true if it makes sense to take the size of this type. To
310 /// get the actual size for a particular target, it is reasonable to use the
311 /// TargetData subsystem to do this.
313 bool isSized() const {
314 // If it's a primitive, it is always sized.
315 if (ID == IntegerTyID || isFloatingPointTy() || ID == PointerTyID ||
318 // If it is not something that can have a size (e.g. a function or label),
319 // it doesn't have a size.
320 if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID)
322 // If it is something that can have a size and it's concrete, it definitely
323 // has a size, otherwise we have to try harder to decide.
324 return !isAbstract() || isSizedDerivedType();
327 /// getPrimitiveSizeInBits - Return the basic size of this type if it is a
328 /// primitive type. These are fixed by LLVM and are not target dependent.
329 /// This will return zero if the type does not have a size or is not a
332 /// Note that this may not reflect the size of memory allocated for an
333 /// instance of the type or the number of bytes that are written when an
334 /// instance of the type is stored to memory. The TargetData class provides
335 /// additional query functions to provide this information.
337 unsigned getPrimitiveSizeInBits() const;
339 /// getScalarSizeInBits - If this is a vector type, return the
340 /// getPrimitiveSizeInBits value for the element type. Otherwise return the
341 /// getPrimitiveSizeInBits value for this type.
342 unsigned getScalarSizeInBits() const;
344 /// getFPMantissaWidth - Return the width of the mantissa of this type. This
345 /// is only valid on floating point types. If the FP type does not
346 /// have a stable mantissa (e.g. ppc long double), this method returns -1.
347 int getFPMantissaWidth() const;
349 /// getForwardedType - Return the type that this type has been resolved to if
350 /// it has been resolved to anything. This is used to implement the
351 /// union-find algorithm for type resolution, and shouldn't be used by general
353 const Type *getForwardedType() const {
354 if (!ForwardType) return 0;
355 return getForwardedTypeInternal();
358 /// getScalarType - If this is a vector type, return the element type,
359 /// otherwise return this.
360 const Type *getScalarType() const;
362 //===--------------------------------------------------------------------===//
363 // Type Iteration support
365 typedef PATypeHandle *subtype_iterator;
366 subtype_iterator subtype_begin() const { return ContainedTys; }
367 subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
369 /// getContainedType - This method is used to implement the type iterator
370 /// (defined a the end of the file). For derived types, this returns the
371 /// types 'contained' in the derived type.
373 const Type *getContainedType(unsigned i) const {
374 assert(i < NumContainedTys && "Index out of range!");
375 return ContainedTys[i].get();
378 /// getNumContainedTypes - Return the number of types in the derived type.
380 unsigned getNumContainedTypes() const { return NumContainedTys; }
382 //===--------------------------------------------------------------------===//
383 // Static members exported by the Type class itself. Useful for getting
384 // instances of Type.
387 /// getPrimitiveType - Return a type based on an identifier.
388 static const Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber);
390 //===--------------------------------------------------------------------===//
391 // These are the builtin types that are always available...
393 static const Type *getVoidTy(LLVMContext &C);
394 static const Type *getLabelTy(LLVMContext &C);
395 static const Type *getFloatTy(LLVMContext &C);
396 static const Type *getDoubleTy(LLVMContext &C);
397 static const Type *getMetadataTy(LLVMContext &C);
398 static const Type *getX86_FP80Ty(LLVMContext &C);
399 static const Type *getFP128Ty(LLVMContext &C);
400 static const Type *getPPC_FP128Ty(LLVMContext &C);
401 static const Type *getX86_MMXTy(LLVMContext &C);
402 static const IntegerType *getIntNTy(LLVMContext &C, unsigned N);
403 static const IntegerType *getInt1Ty(LLVMContext &C);
404 static const IntegerType *getInt8Ty(LLVMContext &C);
405 static const IntegerType *getInt16Ty(LLVMContext &C);
406 static const IntegerType *getInt32Ty(LLVMContext &C);
407 static const IntegerType *getInt64Ty(LLVMContext &C);
409 //===--------------------------------------------------------------------===//
410 // Convenience methods for getting pointer types with one of the above builtin
413 static const PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0);
414 static const PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0);
415 static const PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0);
416 static const PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0);
417 static const PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0);
418 static const PointerType *getX86_MMXPtrTy(LLVMContext &C, unsigned AS = 0);
419 static const PointerType *getIntNPtrTy(LLVMContext &C, unsigned N,
421 static const PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0);
422 static const PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
423 static const PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0);
424 static const PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0);
425 static const PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0);
427 /// Methods for support type inquiry through isa, cast, and dyn_cast:
428 static inline bool classof(const Type *) { return true; }
430 void addRef() const {
431 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
435 void dropRef() const {
436 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
437 assert(RefCount && "No objects are currently referencing this object!");
439 // If this is the last PATypeHolder using this object, and there are no
440 // PATypeHandles using it, the type is dead, delete it now.
441 if (--RefCount == 0 && AbstractTypeUsers.empty())
445 /// addAbstractTypeUser - Notify an abstract type that there is a new user of
446 /// it. This function is called primarily by the PATypeHandle class.
448 void addAbstractTypeUser(AbstractTypeUser *U) const;
450 /// removeAbstractTypeUser - Notify an abstract type that a user of the class
451 /// no longer has a handle to the type. This function is called primarily by
452 /// the PATypeHandle class. When there are no users of the abstract type, it
453 /// is annihilated, because there is no way to get a reference to it ever
456 void removeAbstractTypeUser(AbstractTypeUser *U) const;
458 /// getPointerTo - Return a pointer to the current type. This is equivalent
459 /// to PointerType::get(Foo, AddrSpace).
460 const PointerType *getPointerTo(unsigned AddrSpace = 0) const;
463 /// isSizedDerivedType - Derived types like structures and arrays are sized
464 /// iff all of the members of the type are sized as well. Since asking for
465 /// their size is relatively uncommon, move this operation out of line.
466 bool isSizedDerivedType() const;
468 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
469 virtual void typeBecameConcrete(const DerivedType *AbsTy);
472 // PromoteAbstractToConcrete - This is an internal method used to calculate
473 // change "Abstract" from true to false when types are refined.
474 void PromoteAbstractToConcrete();
475 friend class TypeMapBase;
478 //===----------------------------------------------------------------------===//
479 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
480 // These are defined here because they MUST be inlined, yet are dependent on
481 // the definition of the Type class.
483 inline void PATypeHandle::addUser() {
484 assert(Ty && "Type Handle has a null type!");
485 if (Ty->isAbstract())
486 Ty->addAbstractTypeUser(User);
488 inline void PATypeHandle::removeUser() {
489 if (Ty->isAbstract())
490 Ty->removeAbstractTypeUser(User);
493 // Define inline methods for PATypeHolder.
495 /// get - This implements the forwarding part of the union-find algorithm for
496 /// abstract types. Before every access to the Type*, we check to see if the
497 /// type we are pointing to is forwarding to a new type. If so, we drop our
498 /// reference to the type.
500 inline Type *PATypeHolder::get() const {
501 if (Ty == 0) return 0;
502 const Type *NewTy = Ty->getForwardedType();
503 if (!NewTy) return const_cast<Type*>(Ty);
504 return *const_cast<PATypeHolder*>(this) = NewTy;
507 inline void PATypeHolder::addRef() {
508 if (Ty && Ty->isAbstract())
512 inline void PATypeHolder::dropRef() {
513 if (Ty && Ty->isAbstract())
518 //===----------------------------------------------------------------------===//
519 // Provide specializations of GraphTraits to be able to treat a type as a
520 // graph of sub types.
522 template <> struct GraphTraits<Type*> {
523 typedef Type NodeType;
524 typedef Type::subtype_iterator ChildIteratorType;
526 static inline NodeType *getEntryNode(Type *T) { return T; }
527 static inline ChildIteratorType child_begin(NodeType *N) {
528 return N->subtype_begin();
530 static inline ChildIteratorType child_end(NodeType *N) {
531 return N->subtype_end();
535 template <> struct GraphTraits<const Type*> {
536 typedef const Type NodeType;
537 typedef Type::subtype_iterator ChildIteratorType;
539 static inline NodeType *getEntryNode(const Type *T) { return T; }
540 static inline ChildIteratorType child_begin(NodeType *N) {
541 return N->subtype_begin();
543 static inline ChildIteratorType child_end(NodeType *N) {
544 return N->subtype_end();
548 template <> struct isa_impl<PointerType, Type> {
549 static inline bool doit(const Type &Ty) {
550 return Ty.getTypeID() == Type::PointerTyID;
554 raw_ostream &operator<<(raw_ostream &OS, const Type &T);
556 } // End llvm namespace