1//===-- llvm/DerivedTypes.h - Classes for handling data types ---*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains the declarations of classes that represent "derived
11// types".  These are things like "arrays of x" or "structure of x, y, z" or
12// "function returning x taking (y,z) as parameters", etc...
13//
14// The implementations of these classes live in the Type.cpp file.
15//
16//===----------------------------------------------------------------------===//
17
18#ifndef LLVM_DERIVED_TYPES_H
19#define LLVM_DERIVED_TYPES_H
20
21#include "llvm/Type.h"
22#include "llvm/Support/DataTypes.h"
23
24namespace llvm {
25
26class Value;
27class APInt;
28class LLVMContext;
29template<typename T> class ArrayRef;
30class StringRef;
31
32/// Class to represent integer types. Note that this class is also used to
33/// represent the built-in integer types: Int1Ty, Int8Ty, Int16Ty, Int32Ty and
34/// Int64Ty.
35/// @brief Integer representation type
36class IntegerType : public Type {
37  friend class LLVMContextImpl;
38
39protected:
40  explicit IntegerType(LLVMContext &C, unsigned NumBits) : Type(C, IntegerTyID){
41    setSubclassData(NumBits);
42  }
43public:
44  /// This enum is just used to hold constants we need for IntegerType.
45  enum {
46    MIN_INT_BITS = 1,        ///< Minimum number of bits that can be specified
47    MAX_INT_BITS = (1<<23)-1 ///< Maximum number of bits that can be specified
48      ///< Note that bit width is stored in the Type classes SubclassData field
49      ///< which has 23 bits. This yields a maximum bit width of 8,388,607 bits.
50  };
51
52  /// This static method is the primary way of constructing an IntegerType.
53  /// If an IntegerType with the same NumBits value was previously instantiated,
54  /// that instance will be returned. Otherwise a new one will be created. Only
55  /// one instance with a given NumBits value is ever created.
56  /// @brief Get or create an IntegerType instance.
57  static IntegerType *get(LLVMContext &C, unsigned NumBits);
58
59  /// @brief Get the number of bits in this IntegerType
60  unsigned getBitWidth() const { return getSubclassData(); }
61
62  /// getBitMask - Return a bitmask with ones set for all of the bits
63  /// that can be set by an unsigned version of this type.  This is 0xFF for
64  /// i8, 0xFFFF for i16, etc.
65  uint64_t getBitMask() const {
66    return ~uint64_t(0UL) >> (64-getBitWidth());
67  }
68
69  /// getSignBit - Return a uint64_t with just the most significant bit set (the
70  /// sign bit, if the value is treated as a signed number).
71  uint64_t getSignBit() const {
72    return 1ULL << (getBitWidth()-1);
73  }
74
75  /// For example, this is 0xFF for an 8 bit integer, 0xFFFF for i16, etc.
76  /// @returns a bit mask with ones set for all the bits of this type.
77  /// @brief Get a bit mask for this type.
78  APInt getMask() const;
79
80  /// This method determines if the width of this IntegerType is a power-of-2
81  /// in terms of 8 bit bytes.
82  /// @returns true if this is a power-of-2 byte width.
83  /// @brief Is this a power-of-2 byte-width IntegerType ?
84  bool isPowerOf2ByteWidth() const;
85
86  // Methods for support type inquiry through isa, cast, and dyn_cast.
87  static inline bool classof(const IntegerType *) { return true; }
88  static inline bool classof(const Type *T) {
89    return T->getTypeID() == IntegerTyID;
90  }
91};
92
93
94/// FunctionType - Class to represent function types
95///
96class FunctionType : public Type {
97  FunctionType(const FunctionType &);                   // Do not implement
98  const FunctionType &operator=(const FunctionType &);  // Do not implement
99  FunctionType(Type *Result, ArrayRef<Type*> Params, bool IsVarArgs);
100
101public:
102  /// FunctionType::get - This static method is the primary way of constructing
103  /// a FunctionType.
104  ///
105  static FunctionType *get(Type *Result,
106                           ArrayRef<Type*> Params, bool isVarArg);
107
108  /// FunctionType::get - Create a FunctionType taking no parameters.
109  ///
110  static FunctionType *get(Type *Result, bool isVarArg);
111
112  /// isValidReturnType - Return true if the specified type is valid as a return
113  /// type.
114  static bool isValidReturnType(Type *RetTy);
115
116  /// isValidArgumentType - Return true if the specified type is valid as an
117  /// argument type.
118  static bool isValidArgumentType(Type *ArgTy);
119
120  bool isVarArg() const { return getSubclassData(); }
121  Type *getReturnType() const { return ContainedTys[0]; }
122
123  typedef Type::subtype_iterator param_iterator;
124  param_iterator param_begin() const { return ContainedTys + 1; }
125  param_iterator param_end() const { return &ContainedTys[NumContainedTys]; }
126
127  // Parameter type accessors.
128  Type *getParamType(unsigned i) const { return ContainedTys[i+1]; }
129
130  /// getNumParams - Return the number of fixed parameters this function type
131  /// requires.  This does not consider varargs.
132  ///
133  unsigned getNumParams() const { return NumContainedTys - 1; }
134
135  // Methods for support type inquiry through isa, cast, and dyn_cast.
136  static inline bool classof(const FunctionType *) { return true; }
137  static inline bool classof(const Type *T) {
138    return T->getTypeID() == FunctionTyID;
139  }
140};
141
142
143/// CompositeType - Common super class of ArrayType, StructType, PointerType
144/// and VectorType.
145class CompositeType : public Type {
146protected:
147  explicit CompositeType(LLVMContext &C, TypeID tid) : Type(C, tid) { }
148public:
149
150  /// getTypeAtIndex - Given an index value into the type, return the type of
151  /// the element.
152  ///
153  Type *getTypeAtIndex(const Value *V);
154  Type *getTypeAtIndex(unsigned Idx);
155  bool indexValid(const Value *V) const;
156  bool indexValid(unsigned Idx) const;
157
158  // Methods for support type inquiry through isa, cast, and dyn_cast.
159  static inline bool classof(const CompositeType *) { return true; }
160  static inline bool classof(const Type *T) {
161    return T->getTypeID() == ArrayTyID ||
162           T->getTypeID() == StructTyID ||
163           T->getTypeID() == PointerTyID ||
164           T->getTypeID() == VectorTyID;
165  }
166};
167
168
169/// StructType - Class to represent struct types.  There are two different kinds
170/// of struct types: Literal structs and Identified structs.
171///
172/// Literal struct types (e.g. { i32, i32 }) are uniqued structurally, and must
173/// always have a body when created.  You can get one of these by using one of
174/// the StructType::get() forms.
175///
176/// Identified structs (e.g. %foo or %42) may optionally have a name and are not
177/// uniqued.  The names for identified structs are managed at the LLVMContext
178/// level, so there can only be a single identified struct with a given name in
179/// a particular LLVMContext.  Identified structs may also optionally be opaque
180/// (have no body specified).  You get one of these by using one of the
181/// StructType::create() forms.
182///
183/// Independent of what kind of struct you have, the body of a struct type are
184/// laid out in memory consequtively with the elements directly one after the
185/// other (if the struct is packed) or (if not packed) with padding between the
186/// elements as defined by TargetData (which is required to match what the code
187/// generator for a target expects).
188///
189class StructType : public CompositeType {
190  StructType(const StructType &);                   // Do not implement
191  const StructType &operator=(const StructType &);  // Do not implement
192  StructType(LLVMContext &C)
193    : CompositeType(C, StructTyID), SymbolTableEntry(0) {}
194  enum {
195    // This is the contents of the SubClassData field.
196    SCDB_HasBody = 1,
197    SCDB_Packed = 2,
198    SCDB_IsLiteral = 4,
199    SCDB_IsSized = 8
200  };
201
202  /// SymbolTableEntry - For a named struct that actually has a name, this is a
203  /// pointer to the symbol table entry (maintained by LLVMContext) for the
204  /// struct.  This is null if the type is an literal struct or if it is
205  /// a identified type that has an empty name.
206  ///
207  void *SymbolTableEntry;
208public:
209  ~StructType() {
210    delete [] ContainedTys; // Delete the body.
211  }
212
213  /// StructType::create - This creates an identified struct.
214  static StructType *create(LLVMContext &Context, StringRef Name);
215  static StructType *create(LLVMContext &Context);
216
217  static StructType *create(ArrayRef<Type*> Elements,
218                            StringRef Name,
219                            bool isPacked = false);
220  static StructType *create(ArrayRef<Type*> Elements);
221  static StructType *create(LLVMContext &Context,
222                            ArrayRef<Type*> Elements,
223                            StringRef Name,
224                            bool isPacked = false);
225  static StructType *create(LLVMContext &Context, ArrayRef<Type*> Elements);
226  static StructType *create(StringRef Name, Type *elt1, ...) END_WITH_NULL;
227
228  /// StructType::get - This static method is the primary way to create a
229  /// literal StructType.
230  static StructType *get(LLVMContext &Context, ArrayRef<Type*> Elements,
231                         bool isPacked = false);
232
233  /// StructType::get - Create an empty structure type.
234  ///
235  static StructType *get(LLVMContext &Context, bool isPacked = false);
236
237  /// StructType::get - This static method is a convenience method for creating
238  /// structure types by specifying the elements as arguments.  Note that this
239  /// method always returns a non-packed struct, and requires at least one
240  /// element type.
241  static StructType *get(Type *elt1, ...) END_WITH_NULL;
242
243  bool isPacked() const { return (getSubclassData() & SCDB_Packed) != 0; }
244
245  /// isLiteral - Return true if this type is uniqued by structural
246  /// equivalence, false if it is a struct definition.
247  bool isLiteral() const { return (getSubclassData() & SCDB_IsLiteral) != 0; }
248
249  /// isOpaque - Return true if this is a type with an identity that has no body
250  /// specified yet.  These prints as 'opaque' in .ll files.
251  bool isOpaque() const { return (getSubclassData() & SCDB_HasBody) == 0; }
252
253  /// isSized - Return true if this is a sized type.
254  bool isSized() const;
255
256  /// hasName - Return true if this is a named struct that has a non-empty name.
257  bool hasName() const { return SymbolTableEntry != 0; }
258
259  /// getName - Return the name for this struct type if it has an identity.
260  /// This may return an empty string for an unnamed struct type.  Do not call
261  /// this on an literal type.
262  StringRef getName() const;
263
264  /// setName - Change the name of this type to the specified name, or to a name
265  /// with a suffix if there is a collision.  Do not call this on an literal
266  /// type.
267  void setName(StringRef Name);
268
269  /// setBody - Specify a body for an opaque identified type.
270  void setBody(ArrayRef<Type*> Elements, bool isPacked = false);
271  void setBody(Type *elt1, ...) END_WITH_NULL;
272
273  /// isValidElementType - Return true if the specified type is valid as a
274  /// element type.
275  static bool isValidElementType(Type *ElemTy);
276
277
278  // Iterator access to the elements.
279  typedef Type::subtype_iterator element_iterator;
280  element_iterator element_begin() const { return ContainedTys; }
281  element_iterator element_end() const { return &ContainedTys[NumContainedTys];}
282
283  /// isLayoutIdentical - Return true if this is layout identical to the
284  /// specified struct.
285  bool isLayoutIdentical(StructType *Other) const;
286
287  // Random access to the elements
288  unsigned getNumElements() const { return NumContainedTys; }
289  Type *getElementType(unsigned N) const {
290    assert(N < NumContainedTys && "Element number out of range!");
291    return ContainedTys[N];
292  }
293
294  // Methods for support type inquiry through isa, cast, and dyn_cast.
295  static inline bool classof(const StructType *) { return true; }
296  static inline bool classof(const Type *T) {
297    return T->getTypeID() == StructTyID;
298  }
299};
300
301/// SequentialType - This is the superclass of the array, pointer and vector
302/// type classes.  All of these represent "arrays" in memory.  The array type
303/// represents a specifically sized array, pointer types are unsized/unknown
304/// size arrays, vector types represent specifically sized arrays that
305/// allow for use of SIMD instructions.  SequentialType holds the common
306/// features of all, which stem from the fact that all three lay their
307/// components out in memory identically.
308///
309class SequentialType : public CompositeType {
310  Type *ContainedType;               ///< Storage for the single contained type.
311  SequentialType(const SequentialType &);                  // Do not implement!
312  const SequentialType &operator=(const SequentialType &); // Do not implement!
313
314protected:
315  SequentialType(TypeID TID, Type *ElType)
316    : CompositeType(ElType->getContext(), TID), ContainedType(ElType) {
317    ContainedTys = &ContainedType;
318    NumContainedTys = 1;
319  }
320
321public:
322  Type *getElementType() const { return ContainedTys[0]; }
323
324  // Methods for support type inquiry through isa, cast, and dyn_cast.
325  static inline bool classof(const SequentialType *) { return true; }
326  static inline bool classof(const Type *T) {
327    return T->getTypeID() == ArrayTyID ||
328           T->getTypeID() == PointerTyID ||
329           T->getTypeID() == VectorTyID;
330  }
331};
332
333
334/// ArrayType - Class to represent array types.
335///
336class ArrayType : public SequentialType {
337  uint64_t NumElements;
338
339  ArrayType(const ArrayType &);                   // Do not implement
340  const ArrayType &operator=(const ArrayType &);  // Do not implement
341  ArrayType(Type *ElType, uint64_t NumEl);
342public:
343  /// ArrayType::get - This static method is the primary way to construct an
344  /// ArrayType
345  ///
346  static ArrayType *get(Type *ElementType, uint64_t NumElements);
347
348  /// isValidElementType - Return true if the specified type is valid as a
349  /// element type.
350  static bool isValidElementType(Type *ElemTy);
351
352  uint64_t getNumElements() const { return NumElements; }
353
354  // Methods for support type inquiry through isa, cast, and dyn_cast.
355  static inline bool classof(const ArrayType *) { return true; }
356  static inline bool classof(const Type *T) {
357    return T->getTypeID() == ArrayTyID;
358  }
359};
360
361/// VectorType - Class to represent vector types.
362///
363class VectorType : public SequentialType {
364  unsigned NumElements;
365
366  VectorType(const VectorType &);                   // Do not implement
367  const VectorType &operator=(const VectorType &);  // Do not implement
368  VectorType(Type *ElType, unsigned NumEl);
369public:
370  /// VectorType::get - This static method is the primary way to construct an
371  /// VectorType.
372  ///
373  static VectorType *get(Type *ElementType, unsigned NumElements);
374
375  /// VectorType::getInteger - This static method gets a VectorType with the
376  /// same number of elements as the input type, and the element type is an
377  /// integer type of the same width as the input element type.
378  ///
379  static VectorType *getInteger(VectorType *VTy) {
380    unsigned EltBits = VTy->getElementType()->getPrimitiveSizeInBits();
381    assert(EltBits && "Element size must be of a non-zero size");
382    Type *EltTy = IntegerType::get(VTy->getContext(), EltBits);
383    return VectorType::get(EltTy, VTy->getNumElements());
384  }
385
386  /// VectorType::getExtendedElementVectorType - This static method is like
387  /// getInteger except that the element types are twice as wide as the
388  /// elements in the input type.
389  ///
390  static VectorType *getExtendedElementVectorType(VectorType *VTy) {
391    unsigned EltBits = VTy->getElementType()->getPrimitiveSizeInBits();
392    Type *EltTy = IntegerType::get(VTy->getContext(), EltBits * 2);
393    return VectorType::get(EltTy, VTy->getNumElements());
394  }
395
396  /// VectorType::getTruncatedElementVectorType - This static method is like
397  /// getInteger except that the element types are half as wide as the
398  /// elements in the input type.
399  ///
400  static VectorType *getTruncatedElementVectorType(VectorType *VTy) {
401    unsigned EltBits = VTy->getElementType()->getPrimitiveSizeInBits();
402    assert((EltBits & 1) == 0 &&
403           "Cannot truncate vector element with odd bit-width");
404    Type *EltTy = IntegerType::get(VTy->getContext(), EltBits / 2);
405    return VectorType::get(EltTy, VTy->getNumElements());
406  }
407
408  /// isValidElementType - Return true if the specified type is valid as a
409  /// element type.
410  static bool isValidElementType(Type *ElemTy);
411
412  /// @brief Return the number of elements in the Vector type.
413  unsigned getNumElements() const { return NumElements; }
414
415  /// @brief Return the number of bits in the Vector type.
416  /// Returns zero when the vector is a vector of pointers.
417  unsigned getBitWidth() const {
418    return NumElements * getElementType()->getPrimitiveSizeInBits();
419  }
420
421  // Methods for support type inquiry through isa, cast, and dyn_cast.
422  static inline bool classof(const VectorType *) { return true; }
423  static inline bool classof(const Type *T) {
424    return T->getTypeID() == VectorTyID;
425  }
426};
427
428
429/// PointerType - Class to represent pointers.
430///
431class PointerType : public SequentialType {
432  PointerType(const PointerType &);                   // Do not implement
433  const PointerType &operator=(const PointerType &);  // Do not implement
434  explicit PointerType(Type *ElType, unsigned AddrSpace);
435public:
436  /// PointerType::get - This constructs a pointer to an object of the specified
437  /// type in a numbered address space.
438  static PointerType *get(Type *ElementType, unsigned AddressSpace);
439
440  /// PointerType::getUnqual - This constructs a pointer to an object of the
441  /// specified type in the generic address space (address space zero).
442  static PointerType *getUnqual(Type *ElementType) {
443    return PointerType::get(ElementType, 0);
444  }
445
446  /// isValidElementType - Return true if the specified type is valid as a
447  /// element type.
448  static bool isValidElementType(Type *ElemTy);
449
450  /// @brief Return the address space of the Pointer type.
451  inline unsigned getAddressSpace() const { return getSubclassData(); }
452
453  // Implement support type inquiry through isa, cast, and dyn_cast.
454  static inline bool classof(const PointerType *) { return true; }
455  static inline bool classof(const Type *T) {
456    return T->getTypeID() == PointerTyID;
457  }
458};
459
460} // End llvm namespace
461
462#endif
463