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_IR_DERIVEDTYPES_H
19#define LLVM_IR_DERIVEDTYPES_H
20
21#include "llvm/ADT/ArrayRef.h"
22#include "llvm/ADT/STLExtras.h"
23#include "llvm/ADT/StringRef.h"
24#include "llvm/IR/Type.h"
25#include "llvm/Support/Casting.h"
26#include "llvm/Support/Compiler.h"
27#include <cassert>
28#include <cstdint>
29
30namespace llvm {
31
32class Value;
33class APInt;
34class LLVMContext;
35
36/// Class to represent integer types. Note that this class is also used to
37/// represent the built-in integer types: Int1Ty, Int8Ty, Int16Ty, Int32Ty and
38/// Int64Ty.
39/// Integer representation type
40class IntegerType : public Type {
41 friend class LLVMContextImpl;
42
43protected:
44 explicit IntegerType(LLVMContext &C, unsigned NumBits) : Type(C, IntegerTyID){
45 setSubclassData(NumBits);
46 }
47
48public:
49 /// This enum is just used to hold constants we need for IntegerType.
50 enum {
51 MIN_INT_BITS = 1, ///< Minimum number of bits that can be specified
52 MAX_INT_BITS = (1<<24)-1 ///< Maximum number of bits that can be specified
53 ///< Note that bit width is stored in the Type classes SubclassData field
54 ///< which has 24 bits. This yields a maximum bit width of 16,777,215
55 ///< bits.
56 };
57
58 /// This static method is the primary way of constructing an IntegerType.
59 /// If an IntegerType with the same NumBits value was previously instantiated,
60 /// that instance will be returned. Otherwise a new one will be created. Only
61 /// one instance with a given NumBits value is ever created.
62 /// Get or create an IntegerType instance.
63 static IntegerType *get(LLVMContext &C, unsigned NumBits);
64
65 /// Get the number of bits in this IntegerType
66 unsigned getBitWidth() const { return getSubclassData(); }
67
68 /// Return a bitmask with ones set for all of the bits that can be set by an
69 /// unsigned version of this type. This is 0xFF for i8, 0xFFFF for i16, etc.
70 uint64_t getBitMask() const {
71 return ~uint64_t(0UL) >> (64-getBitWidth());
72 }
73
74 /// Return a uint64_t with just the most significant bit set (the sign bit, if
75 /// the value is treated as a signed number).
76 uint64_t getSignBit() const {
77 return 1ULL << (getBitWidth()-1);
78 }
79
80 /// For example, this is 0xFF for an 8 bit integer, 0xFFFF for i16, etc.
81 /// @returns a bit mask with ones set for all the bits of this type.
82 /// Get a bit mask for this type.
83 APInt getMask() const;
84
85 /// This method determines if the width of this IntegerType is a power-of-2
86 /// in terms of 8 bit bytes.
87 /// @returns true if this is a power-of-2 byte width.
88 /// Is this a power-of-2 byte-width IntegerType ?
89 bool isPowerOf2ByteWidth() const;
90
91 /// Methods for support type inquiry through isa, cast, and dyn_cast.
92 static bool classof(const Type *T) {
93 return T->getTypeID() == IntegerTyID;
94 }
95};
96
97unsigned Type::getIntegerBitWidth() const {
98 return cast<IntegerType>(this)->getBitWidth();
99}
100
101/// Class to represent function types
102///
103class FunctionType : public Type {
104 FunctionType(Type *Result, ArrayRef<Type*> Params, bool IsVarArgs);
105
106public:
107 FunctionType(const FunctionType &) = delete;
108 FunctionType &operator=(const FunctionType &) = delete;
109
110 /// This static method is the primary way of constructing a FunctionType.
111 static FunctionType *get(Type *Result,
112 ArrayRef<Type*> Params, bool isVarArg);
113
114 /// Create a FunctionType taking no parameters.
115 static FunctionType *get(Type *Result, bool isVarArg);
116
117 /// Return true if the specified type is valid as a return type.
118 static bool isValidReturnType(Type *RetTy);
119
120 /// Return true if the specified type is valid as an argument type.
121 static bool isValidArgumentType(Type *ArgTy);
122
123 bool isVarArg() const { return getSubclassData()!=0; }
124 Type *getReturnType() const { return ContainedTys[0]; }
125
126 using param_iterator = Type::subtype_iterator;
127
128 param_iterator param_begin() const { return ContainedTys + 1; }
129 param_iterator param_end() const { return &ContainedTys[NumContainedTys]; }
130 ArrayRef<Type *> params() const {
131 return makeArrayRef(param_begin(), param_end());
132 }
133
134 /// Parameter type accessors.
135 Type *getParamType(unsigned i) const { return ContainedTys[i+1]; }
136
137 /// Return the number of fixed parameters this function type requires.
138 /// This does not consider varargs.
139 unsigned getNumParams() const { return NumContainedTys - 1; }
140
141 /// Methods for support type inquiry through isa, cast, and dyn_cast.
142 static bool classof(const Type *T) {
143 return T->getTypeID() == FunctionTyID;
144 }
145};
146static_assert(alignof(FunctionType) >= alignof(Type *),
147 "Alignment sufficient for objects appended to FunctionType");
148
149bool Type::isFunctionVarArg() const {
150 return cast<FunctionType>(this)->isVarArg();
151}
152
153Type *Type::getFunctionParamType(unsigned i) const {
154 return cast<FunctionType>(this)->getParamType(i);
155}
156
157unsigned Type::getFunctionNumParams() const {
158 return cast<FunctionType>(this)->getNumParams();
159}
160
161/// Common super class of ArrayType, StructType and VectorType.
162class CompositeType : public Type {
163protected:
164 explicit CompositeType(LLVMContext &C, TypeID tid) : Type(C, tid) {}
165
166public:
167 /// Given an index value into the type, return the type of the element.
168 Type *getTypeAtIndex(const Value *V) const;
169 Type *getTypeAtIndex(unsigned Idx) const;
170 bool indexValid(const Value *V) const;
171 bool indexValid(unsigned Idx) const;
172
173 /// Methods for support type inquiry through isa, cast, and dyn_cast.
174 static bool classof(const Type *T) {
175 return T->getTypeID() == ArrayTyID ||
176 T->getTypeID() == StructTyID ||
177 T->getTypeID() == VectorTyID;
178 }
179};
180
181/// Class to represent struct types. There are two different kinds of struct
182/// types: Literal structs and Identified structs.
183///
184/// Literal struct types (e.g. { i32, i32 }) are uniqued structurally, and must
185/// always have a body when created. You can get one of these by using one of
186/// the StructType::get() forms.
187///
188/// Identified structs (e.g. %foo or %42) may optionally have a name and are not
189/// uniqued. The names for identified structs are managed at the LLVMContext
190/// level, so there can only be a single identified struct with a given name in
191/// a particular LLVMContext. Identified structs may also optionally be opaque
192/// (have no body specified). You get one of these by using one of the
193/// StructType::create() forms.
194///
195/// Independent of what kind of struct you have, the body of a struct type are
196/// laid out in memory consecutively with the elements directly one after the
197/// other (if the struct is packed) or (if not packed) with padding between the
198/// elements as defined by DataLayout (which is required to match what the code
199/// generator for a target expects).
200///
201class StructType : public CompositeType {
202 StructType(LLVMContext &C) : CompositeType(C, StructTyID) {}
203
204 enum {
205 /// This is the contents of the SubClassData field.
206 SCDB_HasBody = 1,
207 SCDB_Packed = 2,
208 SCDB_IsLiteral = 4,
209 SCDB_IsSized = 8
210 };
211
212 /// For a named struct that actually has a name, this is a pointer to the
213 /// symbol table entry (maintained by LLVMContext) for the struct.
214 /// This is null if the type is an literal struct or if it is a identified
215 /// type that has an empty name.
216 void *SymbolTableEntry = nullptr;
217
218public:
219 StructType(const StructType &) = delete;
220 StructType &operator=(const StructType &) = delete;
221
222 /// This creates an identified struct.
223 static StructType *create(LLVMContext &Context, StringRef Name);
224 static StructType *create(LLVMContext &Context);
225
226 static StructType *create(ArrayRef<Type *> Elements, StringRef Name,
227 bool isPacked = false);
228 static StructType *create(ArrayRef<Type *> Elements);
229 static StructType *create(LLVMContext &Context, ArrayRef<Type *> Elements,
230 StringRef Name, bool isPacked = false);
231 static StructType *create(LLVMContext &Context, ArrayRef<Type *> Elements);
232 template <class... Tys>
233 static typename std::enable_if<are_base_of<Type, Tys...>::value,
234 StructType *>::type
235 create(StringRef Name, Type *elt1, Tys *... elts) {
236 assert(elt1 && "Cannot create a struct type with no elements with this");
237 SmallVector<llvm::Type *, 8> StructFields({elt1, elts...});
238 return create(StructFields, Name);
239 }
240
241 /// This static method is the primary way to create a literal StructType.
242 static StructType *get(LLVMContext &Context, ArrayRef<Type*> Elements,
243 bool isPacked = false);
244
245 /// Create an empty structure type.
246 static StructType *get(LLVMContext &Context, bool isPacked = false);
247
248 /// This static method is a convenience method for creating structure types by
249 /// specifying the elements as arguments. Note that this method always returns
250 /// a non-packed struct, and requires at least one element type.
251 template <class... Tys>
252 static typename std::enable_if<are_base_of<Type, Tys...>::value,
253 StructType *>::type
254 get(Type *elt1, Tys *... elts) {
255 assert(elt1 && "Cannot create a struct type with no elements with this");
256 LLVMContext &Ctx = elt1->getContext();
257 SmallVector<llvm::Type *, 8> StructFields({elt1, elts...});
258 return llvm::StructType::get(Ctx, StructFields);
259 }
260
261 bool isPacked() const { return (getSubclassData() & SCDB_Packed) != 0; }
262
263 /// Return true if this type is uniqued by structural equivalence, false if it
264 /// is a struct definition.
265 bool isLiteral() const { return (getSubclassData() & SCDB_IsLiteral) != 0; }
266
267 /// Return true if this is a type with an identity that has no body specified
268 /// yet. These prints as 'opaque' in .ll files.
269 bool isOpaque() const { return (getSubclassData() & SCDB_HasBody) == 0; }
270
271 /// isSized - Return true if this is a sized type.
272 bool isSized(SmallPtrSetImpl<Type *> *Visited = nullptr) const;
273
274 /// Return true if this is a named struct that has a non-empty name.
275 bool hasName() const { return SymbolTableEntry != nullptr; }
276
277 /// Return the name for this struct type if it has an identity.
278 /// This may return an empty string for an unnamed struct type. Do not call
279 /// this on an literal type.
280 StringRef getName() const;
281
282 /// Change the name of this type to the specified name, or to a name with a
283 /// suffix if there is a collision. Do not call this on an literal type.
284 void setName(StringRef Name);
285
286 /// Specify a body for an opaque identified type.
287 void setBody(ArrayRef<Type*> Elements, bool isPacked = false);
288
289 template <typename... Tys>
290 typename std::enable_if<are_base_of<Type, Tys...>::value, void>::type
291 setBody(Type *elt1, Tys *... elts) {
292 assert(elt1 && "Cannot create a struct type with no elements with this");
293 SmallVector<llvm::Type *, 8> StructFields({elt1, elts...});
294 setBody(StructFields);
295 }
296
297 /// Return true if the specified type is valid as a element type.
298 static bool isValidElementType(Type *ElemTy);
299
300 // Iterator access to the elements.
301 using element_iterator = Type::subtype_iterator;
302
303 element_iterator element_begin() const { return ContainedTys; }
304 element_iterator element_end() const { return &ContainedTys[NumContainedTys];}
305 ArrayRef<Type *> const elements() const {
306 return makeArrayRef(element_begin(), element_end());
307 }
308
309 /// Return true if this is layout identical to the specified struct.
310 bool isLayoutIdentical(StructType *Other) const;
311
312 /// Random access to the elements
313 unsigned getNumElements() const { return NumContainedTys; }
314 Type *getElementType(unsigned N) const {
315 assert(N < NumContainedTys && "Element number out of range!");
316 return ContainedTys[N];
317 }
318
319 /// Methods for support type inquiry through isa, cast, and dyn_cast.
320 static bool classof(const Type *T) {
321 return T->getTypeID() == StructTyID;
322 }
323};
324
325StringRef Type::getStructName() const {
326 return cast<StructType>(this)->getName();
327}
328
329unsigned Type::getStructNumElements() const {
330 return cast<StructType>(this)->getNumElements();
331}
332
333Type *Type::getStructElementType(unsigned N) const {
334 return cast<StructType>(this)->getElementType(N);
335}
336
337/// This is the superclass of the array and vector type classes. Both of these
338/// represent "arrays" in memory. The array type represents a specifically sized
339/// array, and the vector type represents a specifically sized array that allows
340/// for use of SIMD instructions. SequentialType holds the common features of
341/// both, which stem from the fact that both lay their components out in memory
342/// identically.
343class SequentialType : public CompositeType {
344 Type *ContainedType; ///< Storage for the single contained type.
345 uint64_t NumElements;
346
347protected:
348 SequentialType(TypeID TID, Type *ElType, uint64_t NumElements)
349 : CompositeType(ElType->getContext(), TID), ContainedType(ElType),
350 NumElements(NumElements) {
351 ContainedTys = &ContainedType;
352 NumContainedTys = 1;
353 }
354
355public:
356 SequentialType(const SequentialType &) = delete;
357 SequentialType &operator=(const SequentialType &) = delete;
358
359 uint64_t getNumElements() const { return NumElements; }
360 Type *getElementType() const { return ContainedType; }
361
362 /// Methods for support type inquiry through isa, cast, and dyn_cast.
363 static bool classof(const Type *T) {
364 return T->getTypeID() == ArrayTyID || T->getTypeID() == VectorTyID;
365 }
366};
367
368/// Class to represent array types.
369class ArrayType : public SequentialType {
370 ArrayType(Type *ElType, uint64_t NumEl);
371
372public:
373 ArrayType(const ArrayType &) = delete;
374 ArrayType &operator=(const ArrayType &) = delete;
375
376 /// This static method is the primary way to construct an ArrayType
377 static ArrayType *get(Type *ElementType, uint64_t NumElements);
378
379 /// Return true if the specified type is valid as a element type.
380 static bool isValidElementType(Type *ElemTy);
381
382 /// Methods for support type inquiry through isa, cast, and dyn_cast.
383 static bool classof(const Type *T) {
384 return T->getTypeID() == ArrayTyID;
385 }
386};
387
388uint64_t Type::getArrayNumElements() const {
389 return cast<ArrayType>(this)->getNumElements();
390}
391
392/// Class to represent vector types.
393class VectorType : public SequentialType {
394 VectorType(Type *ElType, unsigned NumEl);
395
396public:
397 VectorType(const VectorType &) = delete;
398 VectorType &operator=(const VectorType &) = delete;
399
400 /// This static method is the primary way to construct an VectorType.
401 static VectorType *get(Type *ElementType, unsigned NumElements);
402
403 /// This static method gets a VectorType with the same number of elements as
404 /// the input type, and the element type is an integer type of the same width
405 /// as the input element type.
406 static VectorType *getInteger(VectorType *VTy) {
407 unsigned EltBits = VTy->getElementType()->getPrimitiveSizeInBits();
408 assert(EltBits && "Element size must be of a non-zero size");
409 Type *EltTy = IntegerType::get(VTy->getContext(), EltBits);
410 return VectorType::get(EltTy, VTy->getNumElements());
411 }
412
413 /// This static method is like getInteger except that the element types are
414 /// twice as wide as the elements in the input type.
415 static VectorType *getExtendedElementVectorType(VectorType *VTy) {
416 unsigned EltBits = VTy->getElementType()->getPrimitiveSizeInBits();
417 Type *EltTy = IntegerType::get(VTy->getContext(), EltBits * 2);
418 return VectorType::get(EltTy, VTy->getNumElements());
419 }
420
421 /// This static method is like getInteger except that the element types are
422 /// half as wide as the elements in the input type.
423 static VectorType *getTruncatedElementVectorType(VectorType *VTy) {
424 unsigned EltBits = VTy->getElementType()->getPrimitiveSizeInBits();
425 assert((EltBits & 1) == 0 &&
426 "Cannot truncate vector element with odd bit-width");
427 Type *EltTy = IntegerType::get(VTy->getContext(), EltBits / 2);
428 return VectorType::get(EltTy, VTy->getNumElements());
429 }
430
431 /// This static method returns a VectorType with half as many elements as the
432 /// input type and the same element type.
433 static VectorType *getHalfElementsVectorType(VectorType *VTy) {
434 unsigned NumElts = VTy->getNumElements();
435 assert ((NumElts & 1) == 0 &&
436 "Cannot halve vector with odd number of elements.");
437 return VectorType::get(VTy->getElementType(), NumElts/2);
438 }
439
440 /// This static method returns a VectorType with twice as many elements as the
441 /// input type and the same element type.
442 static VectorType *getDoubleElementsVectorType(VectorType *VTy) {
443 unsigned NumElts = VTy->getNumElements();
444 return VectorType::get(VTy->getElementType(), NumElts*2);
445 }
446
447 /// Return true if the specified type is valid as a element type.
448 static bool isValidElementType(Type *ElemTy);
449
450 /// Return the number of bits in the Vector type.
451 /// Returns zero when the vector is a vector of pointers.
452 unsigned getBitWidth() const {
453 return getNumElements() * getElementType()->getPrimitiveSizeInBits();
454 }
455
456 /// Methods for support type inquiry through isa, cast, and dyn_cast.
457 static bool classof(const Type *T) {
458 return T->getTypeID() == VectorTyID;
459 }
460};
461
462unsigned Type::getVectorNumElements() const {
463 return cast<VectorType>(this)->getNumElements();
464}
465
466/// Class to represent pointers.
467class PointerType : public Type {
468 explicit PointerType(Type *ElType, unsigned AddrSpace);
469
470 Type *PointeeTy;
471
472public:
473 PointerType(const PointerType &) = delete;
474 PointerType &operator=(const PointerType &) = delete;
475
476 /// This constructs a pointer to an object of the specified type in a numbered
477 /// address space.
478 static PointerType *get(Type *ElementType, unsigned AddressSpace);
479
480 /// This constructs a pointer to an object of the specified type in the
481 /// generic address space (address space zero).
482 static PointerType *getUnqual(Type *ElementType) {
483 return PointerType::get(ElementType, 0);
484 }
485
486 Type *getElementType() const { return PointeeTy; }
487
488 /// Return true if the specified type is valid as a element type.
489 static bool isValidElementType(Type *ElemTy);
490
491 /// Return true if we can load or store from a pointer to this type.
492 static bool isLoadableOrStorableType(Type *ElemTy);
493
494 /// Return the address space of the Pointer type.
495 inline unsigned getAddressSpace() const { return getSubclassData(); }
496
497 /// Implement support type inquiry through isa, cast, and dyn_cast.
498 static bool classof(const Type *T) {
499 return T->getTypeID() == PointerTyID;
500 }
501};
502
503unsigned Type::getPointerAddressSpace() const {
504 return cast<PointerType>(getScalarType())->getAddressSpace();
505}
506
507} // end namespace llvm
508
509#endif // LLVM_IR_DERIVEDTYPES_H
510