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 = LabelTyID,
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 /// getTypeID - Return the type id for the type. This will return one
186 /// of the TypeID enum elements defined above.
188 inline TypeID getTypeID() const { return ID; }
190 /// isVoidTy - Return true if this is 'void'.
191 bool isVoidTy() const { return ID == VoidTyID; }
193 /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type.
194 bool isFloatTy() const { return ID == FloatTyID; }
196 /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type.
197 bool isDoubleTy() const { return ID == DoubleTyID; }
199 /// isX86_FP80Ty - Return true if this is x86 long double.
200 bool isX86_FP80Ty() const { return ID == X86_FP80TyID; }
202 /// isFP128Ty - Return true if this is 'fp128'.
203 bool isFP128Ty() const { return ID == FP128TyID; }
205 /// isPPC_FP128Ty - Return true if this is powerpc long double.
206 bool isPPC_FP128Ty() const { return ID == PPC_FP128TyID; }
208 /// isLabelTy - Return true if this is 'label'.
209 bool isLabelTy() const { return ID == LabelTyID; }
211 /// isMetadataTy - Return true if this is 'metadata'.
212 bool isMetadataTy() const { return ID == MetadataTyID; }
214 /// getDescription - Return the string representation of the type.
215 std::string getDescription() const;
217 /// isIntegerTy - True if this is an instance of IntegerType.
219 bool isIntegerTy() const { return ID == IntegerTyID; }
221 /// isIntegerTy - Return true if this is an IntegerType of the given width.
222 bool isIntegerTy(unsigned Bitwidth) const;
224 /// isIntOrIntVectorTy - Return true if this is an integer type or a vector of
227 bool isIntOrIntVectorTy() const;
229 /// isFloatingPointTy - Return true if this is one of the five floating point
231 bool isFloatingPointTy() const { return ID == FloatTyID || ID == DoubleTyID ||
232 ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; }
234 /// isFPOrFPVectorTy - Return true if this is a FP type or a vector of FP.
236 bool isFPOrFPVectorTy() 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 /// isArrayTy - True if this is an instance of ArrayType.
248 bool isArrayTy() const { return ID == ArrayTyID; }
250 /// isPointerTy - True if this is an instance of PointerType.
252 bool isPointerTy() const { return ID == PointerTyID; }
254 /// isVectorTy - True if this is an instance of VectorType.
256 bool isVectorTy() const { return ID == VectorTyID; }
258 /// isAbstract - True if the type is either an Opaque type, or is a derived
259 /// type that includes an opaque type somewhere in it.
261 inline bool isAbstract() const { return Abstract; }
263 /// canLosslesslyBitCastTo - Return true if this type could be converted
264 /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts
265 /// are valid for types of the same size only where no re-interpretation of
266 /// the bits is done.
267 /// @brief Determine if this type could be losslessly bitcast to Ty
268 bool canLosslesslyBitCastTo(const Type *Ty) const;
271 /// Here are some useful little methods to query what type derived types are
272 /// Note that all other types can just compare to see if this == Type::xxxTy;
274 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
275 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
277 /// isFirstClassType - Return true if the type is "first class", meaning it
278 /// is a valid type for a Value.
280 inline bool isFirstClassType() const {
281 // There are more first-class kinds than non-first-class kinds, so a
282 // negative test is simpler than a positive one.
283 return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID;
286 /// isSingleValueType - Return true if the type is a valid type for a
287 /// virtual register in codegen. This includes all first-class types
288 /// except struct and array types.
290 inline bool isSingleValueType() const {
291 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
292 ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID;
295 /// isAggregateType - Return true if the type is an aggregate type. This
296 /// means it is valid as the first operand of an insertvalue or
297 /// extractvalue instruction. This includes struct and array types, but
298 /// does not include vector types.
300 inline bool isAggregateType() const {
301 return ID == StructTyID || ID == ArrayTyID || ID == UnionTyID;
304 /// isSized - Return true if it makes sense to take the size of this type. To
305 /// get the actual size for a particular target, it is reasonable to use the
306 /// TargetData subsystem to do this.
308 bool isSized() const {
309 // If it's a primitive, it is always sized.
310 if (ID == IntegerTyID || isFloatingPointTy() || ID == PointerTyID)
312 // If it is not something that can have a size (e.g. a function or label),
313 // it doesn't have a size.
314 if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID &&
317 // If it is something that can have a size and it's concrete, it definitely
318 // has a size, otherwise we have to try harder to decide.
319 return !isAbstract() || isSizedDerivedType();
322 /// getPrimitiveSizeInBits - Return the basic size of this type if it is a
323 /// primitive type. These are fixed by LLVM and are not target dependent.
324 /// This will return zero if the type does not have a size or is not a
327 /// Note that this may not reflect the size of memory allocated for an
328 /// instance of the type or the number of bytes that are written when an
329 /// instance of the type is stored to memory. The TargetData class provides
330 /// additional query functions to provide this information.
332 unsigned getPrimitiveSizeInBits() const;
334 /// getScalarSizeInBits - If this is a vector type, return the
335 /// getPrimitiveSizeInBits value for the element type. Otherwise return the
336 /// getPrimitiveSizeInBits value for this type.
337 unsigned getScalarSizeInBits() const;
339 /// getFPMantissaWidth - Return the width of the mantissa of this type. This
340 /// is only valid on floating point types. If the FP type does not
341 /// have a stable mantissa (e.g. ppc long double), this method returns -1.
342 int getFPMantissaWidth() const;
344 /// getForwardedType - Return the type that this type has been resolved to if
345 /// it has been resolved to anything. This is used to implement the
346 /// union-find algorithm for type resolution, and shouldn't be used by general
348 const Type *getForwardedType() const {
349 if (!ForwardType) return 0;
350 return getForwardedTypeInternal();
353 /// getVAArgsPromotedType - Return the type an argument of this type
354 /// will be promoted to if passed through a variable argument
356 const Type *getVAArgsPromotedType(LLVMContext &C) const;
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 IntegerType *getInt1Ty(LLVMContext &C);
402 static const IntegerType *getInt8Ty(LLVMContext &C);
403 static const IntegerType *getInt16Ty(LLVMContext &C);
404 static const IntegerType *getInt32Ty(LLVMContext &C);
405 static const IntegerType *getInt64Ty(LLVMContext &C);
407 //===--------------------------------------------------------------------===//
408 // Convenience methods for getting pointer types with one of the above builtin
411 static const PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0);
412 static const PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0);
413 static const PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0);
414 static const PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0);
415 static const PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0);
416 static const PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0);
417 static const PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
418 static const PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0);
419 static const PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0);
420 static const PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0);
422 /// Methods for support type inquiry through isa, cast, and dyn_cast:
423 static inline bool classof(const Type *) { return true; }
425 void addRef() const {
426 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
430 void dropRef() const {
431 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
432 assert(RefCount && "No objects are currently referencing this object!");
434 // If this is the last PATypeHolder using this object, and there are no
435 // PATypeHandles using it, the type is dead, delete it now.
436 if (--RefCount == 0 && AbstractTypeUsers.empty())
440 /// addAbstractTypeUser - Notify an abstract type that there is a new user of
441 /// it. This function is called primarily by the PATypeHandle class.
443 void addAbstractTypeUser(AbstractTypeUser *U) const;
445 /// removeAbstractTypeUser - Notify an abstract type that a user of the class
446 /// no longer has a handle to the type. This function is called primarily by
447 /// the PATypeHandle class. When there are no users of the abstract type, it
448 /// is annihilated, because there is no way to get a reference to it ever
451 void removeAbstractTypeUser(AbstractTypeUser *U) const;
453 /// getPointerTo - Return a pointer to the current type. This is equivalent
454 /// to PointerType::get(Foo, AddrSpace).
455 const PointerType *getPointerTo(unsigned AddrSpace = 0) const;
458 /// isSizedDerivedType - Derived types like structures and arrays are sized
459 /// iff all of the members of the type are sized as well. Since asking for
460 /// their size is relatively uncommon, move this operation out of line.
461 bool isSizedDerivedType() const;
463 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
464 virtual void typeBecameConcrete(const DerivedType *AbsTy);
467 // PromoteAbstractToConcrete - This is an internal method used to calculate
468 // change "Abstract" from true to false when types are refined.
469 void PromoteAbstractToConcrete();
470 friend class TypeMapBase;
473 //===----------------------------------------------------------------------===//
474 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
475 // These are defined here because they MUST be inlined, yet are dependent on
476 // the definition of the Type class.
478 inline void PATypeHandle::addUser() {
479 assert(Ty && "Type Handle has a null type!");
480 if (Ty->isAbstract())
481 Ty->addAbstractTypeUser(User);
483 inline void PATypeHandle::removeUser() {
484 if (Ty->isAbstract())
485 Ty->removeAbstractTypeUser(User);
488 // Define inline methods for PATypeHolder.
490 /// get - This implements the forwarding part of the union-find algorithm for
491 /// abstract types. Before every access to the Type*, we check to see if the
492 /// type we are pointing to is forwarding to a new type. If so, we drop our
493 /// reference to the type.
495 inline Type* PATypeHolder::get() const {
496 const Type *NewTy = Ty->getForwardedType();
497 if (!NewTy) return const_cast<Type*>(Ty);
498 return *const_cast<PATypeHolder*>(this) = NewTy;
501 inline void PATypeHolder::addRef() {
502 assert(Ty && "Type Holder has a null type!");
503 if (Ty->isAbstract())
507 inline void PATypeHolder::dropRef() {
508 if (Ty->isAbstract())
513 //===----------------------------------------------------------------------===//
514 // Provide specializations of GraphTraits to be able to treat a type as a
515 // graph of sub types...
517 template <> struct GraphTraits<Type*> {
518 typedef Type NodeType;
519 typedef Type::subtype_iterator ChildIteratorType;
521 static inline NodeType *getEntryNode(Type *T) { return T; }
522 static inline ChildIteratorType child_begin(NodeType *N) {
523 return N->subtype_begin();
525 static inline ChildIteratorType child_end(NodeType *N) {
526 return N->subtype_end();
530 template <> struct GraphTraits<const Type*> {
531 typedef const Type NodeType;
532 typedef Type::subtype_iterator ChildIteratorType;
534 static inline NodeType *getEntryNode(const Type *T) { return T; }
535 static inline ChildIteratorType child_begin(NodeType *N) {
536 return N->subtype_begin();
538 static inline ChildIteratorType child_end(NodeType *N) {
539 return N->subtype_end();
543 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
544 return Ty.getTypeID() == Type::PointerTyID;
547 raw_ostream &operator<<(raw_ostream &OS, const Type &T);
549 } // End llvm namespace