1 //===- llvm/Type.h - Classes for handling data types ------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains the declaration of the Type class.  For more "Type"
10 // stuff, look in DerivedTypes.h.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_IR_TYPE_H
15 #define LLVM_IR_TYPE_H
16 
17 #include "llvm/ADT/APFloat.h"
18 #include "llvm/ADT/ArrayRef.h"
19 #include "llvm/ADT/SmallPtrSet.h"
20 #include "llvm/Support/CBindingWrapping.h"
21 #include "llvm/Support/Casting.h"
22 #include "llvm/Support/Compiler.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/TypeSize.h"
25 #include <cassert>
26 #include <cstdint>
27 #include <iterator>
28 
29 namespace llvm {
30 
31 template<class GraphType> struct GraphTraits;
32 class IntegerType;
33 class LLVMContext;
34 class PointerType;
35 class raw_ostream;
36 class StringRef;
37 
38 /// The instances of the Type class are immutable: once they are created,
39 /// they are never changed.  Also note that only one instance of a particular
40 /// type is ever created.  Thus seeing if two types are equal is a matter of
41 /// doing a trivial pointer comparison. To enforce that no two equal instances
42 /// are created, Type instances can only be created via static factory methods
43 /// in class Type and in derived classes.  Once allocated, Types are never
44 /// free'd.
45 ///
46 class Type {
47 public:
48   //===--------------------------------------------------------------------===//
49   /// Definitions of all of the base types for the Type system.  Based on this
50   /// value, you can cast to a class defined in DerivedTypes.h.
51   /// Note: If you add an element to this, you need to add an element to the
52   /// Type::getPrimitiveType function, or else things will break!
53   /// Also update LLVMTypeKind and LLVMGetTypeKind () in the C binding.
54   ///
55   enum TypeID {
56     // PrimitiveTypes
57     HalfTyID = 0,  ///< 16-bit floating point type
58     BFloatTyID,    ///< 16-bit floating point type (7-bit significand)
59     FloatTyID,     ///< 32-bit floating point type
60     DoubleTyID,    ///< 64-bit floating point type
61     X86_FP80TyID,  ///< 80-bit floating point type (X87)
62     FP128TyID,     ///< 128-bit floating point type (112-bit significand)
63     PPC_FP128TyID, ///< 128-bit floating point type (two 64-bits, PowerPC)
64     VoidTyID,      ///< type with no size
65     LabelTyID,     ///< Labels
66     MetadataTyID,  ///< Metadata
67     X86_MMXTyID,   ///< MMX vectors (64 bits, X86 specific)
68     X86_AMXTyID,   ///< AMX vectors (8192 bits, X86 specific)
69     TokenTyID,     ///< Tokens
70 
71     // Derived types... see DerivedTypes.h file.
72     IntegerTyID,       ///< Arbitrary bit width integers
73     FunctionTyID,      ///< Functions
74     PointerTyID,       ///< Pointers
75     StructTyID,        ///< Structures
76     ArrayTyID,         ///< Arrays
77     FixedVectorTyID,   ///< Fixed width SIMD vector type
78     ScalableVectorTyID ///< Scalable SIMD vector type
79   };
80 
81 private:
82   /// This refers to the LLVMContext in which this type was uniqued.
83   LLVMContext &Context;
84 
85   TypeID   ID : 8;            // The current base type of this type.
86   unsigned SubclassData : 24; // Space for subclasses to store data.
87                               // Note that this should be synchronized with
88                               // MAX_INT_BITS value in IntegerType class.
89 
90 protected:
91   friend class LLVMContextImpl;
92 
Type(LLVMContext & C,TypeID tid)93   explicit Type(LLVMContext &C, TypeID tid)
94     : Context(C), ID(tid), SubclassData(0) {}
95   ~Type() = default;
96 
getSubclassData()97   unsigned getSubclassData() const { return SubclassData; }
98 
setSubclassData(unsigned val)99   void setSubclassData(unsigned val) {
100     SubclassData = val;
101     // Ensure we don't have any accidental truncation.
102     assert(getSubclassData() == val && "Subclass data too large for field");
103   }
104 
105   /// Keeps track of how many Type*'s there are in the ContainedTys list.
106   unsigned NumContainedTys = 0;
107 
108   /// A pointer to the array of Types contained by this Type. For example, this
109   /// includes the arguments of a function type, the elements of a structure,
110   /// the pointee of a pointer, the element type of an array, etc. This pointer
111   /// may be 0 for types that don't contain other types (Integer, Double,
112   /// Float).
113   Type * const *ContainedTys = nullptr;
114 
115 public:
116   /// Print the current type.
117   /// Omit the type details if \p NoDetails == true.
118   /// E.g., let %st = type { i32, i16 }
119   /// When \p NoDetails is true, we only print %st.
120   /// Put differently, \p NoDetails prints the type as if
121   /// inlined with the operands when printing an instruction.
122   void print(raw_ostream &O, bool IsForDebug = false,
123              bool NoDetails = false) const;
124 
125   void dump() const;
126 
127   /// Return the LLVMContext in which this type was uniqued.
getContext()128   LLVMContext &getContext() const { return Context; }
129 
130   //===--------------------------------------------------------------------===//
131   // Accessors for working with types.
132   //
133 
134   /// Return the type id for the type. This will return one of the TypeID enum
135   /// elements defined above.
getTypeID()136   TypeID getTypeID() const { return ID; }
137 
138   /// Return true if this is 'void'.
isVoidTy()139   bool isVoidTy() const { return getTypeID() == VoidTyID; }
140 
141   /// Return true if this is 'half', a 16-bit IEEE fp type.
isHalfTy()142   bool isHalfTy() const { return getTypeID() == HalfTyID; }
143 
144   /// Return true if this is 'bfloat', a 16-bit bfloat type.
isBFloatTy()145   bool isBFloatTy() const { return getTypeID() == BFloatTyID; }
146 
147   /// Return true if this is 'float', a 32-bit IEEE fp type.
isFloatTy()148   bool isFloatTy() const { return getTypeID() == FloatTyID; }
149 
150   /// Return true if this is 'double', a 64-bit IEEE fp type.
isDoubleTy()151   bool isDoubleTy() const { return getTypeID() == DoubleTyID; }
152 
153   /// Return true if this is x86 long double.
isX86_FP80Ty()154   bool isX86_FP80Ty() const { return getTypeID() == X86_FP80TyID; }
155 
156   /// Return true if this is 'fp128'.
isFP128Ty()157   bool isFP128Ty() const { return getTypeID() == FP128TyID; }
158 
159   /// Return true if this is powerpc long double.
isPPC_FP128Ty()160   bool isPPC_FP128Ty() const { return getTypeID() == PPC_FP128TyID; }
161 
162   /// Return true if this is one of the six floating-point types
isFloatingPointTy()163   bool isFloatingPointTy() const {
164     return getTypeID() == HalfTyID || getTypeID() == BFloatTyID ||
165            getTypeID() == FloatTyID || getTypeID() == DoubleTyID ||
166            getTypeID() == X86_FP80TyID || getTypeID() == FP128TyID ||
167            getTypeID() == PPC_FP128TyID;
168   }
169 
getFltSemantics()170   const fltSemantics &getFltSemantics() const {
171     switch (getTypeID()) {
172     case HalfTyID: return APFloat::IEEEhalf();
173     case BFloatTyID: return APFloat::BFloat();
174     case FloatTyID: return APFloat::IEEEsingle();
175     case DoubleTyID: return APFloat::IEEEdouble();
176     case X86_FP80TyID: return APFloat::x87DoubleExtended();
177     case FP128TyID: return APFloat::IEEEquad();
178     case PPC_FP128TyID: return APFloat::PPCDoubleDouble();
179     default: llvm_unreachable("Invalid floating type");
180     }
181   }
182 
183   /// Return true if this is X86 MMX.
isX86_MMXTy()184   bool isX86_MMXTy() const { return getTypeID() == X86_MMXTyID; }
185 
186   /// Return true if this is X86 AMX.
isX86_AMXTy()187   bool isX86_AMXTy() const { return getTypeID() == X86_AMXTyID; }
188 
189   /// Return true if this is a FP type or a vector of FP.
isFPOrFPVectorTy()190   bool isFPOrFPVectorTy() const { return getScalarType()->isFloatingPointTy(); }
191 
192   /// Return true if this is 'label'.
isLabelTy()193   bool isLabelTy() const { return getTypeID() == LabelTyID; }
194 
195   /// Return true if this is 'metadata'.
isMetadataTy()196   bool isMetadataTy() const { return getTypeID() == MetadataTyID; }
197 
198   /// Return true if this is 'token'.
isTokenTy()199   bool isTokenTy() const { return getTypeID() == TokenTyID; }
200 
201   /// True if this is an instance of IntegerType.
isIntegerTy()202   bool isIntegerTy() const { return getTypeID() == IntegerTyID; }
203 
204   /// Return true if this is an IntegerType of the given width.
205   bool isIntegerTy(unsigned Bitwidth) const;
206 
207   /// Return true if this is an integer type or a vector of integer types.
isIntOrIntVectorTy()208   bool isIntOrIntVectorTy() const { return getScalarType()->isIntegerTy(); }
209 
210   /// Return true if this is an integer type or a vector of integer types of
211   /// the given width.
isIntOrIntVectorTy(unsigned BitWidth)212   bool isIntOrIntVectorTy(unsigned BitWidth) const {
213     return getScalarType()->isIntegerTy(BitWidth);
214   }
215 
216   /// Return true if this is an integer type or a pointer type.
isIntOrPtrTy()217   bool isIntOrPtrTy() const { return isIntegerTy() || isPointerTy(); }
218 
219   /// True if this is an instance of FunctionType.
isFunctionTy()220   bool isFunctionTy() const { return getTypeID() == FunctionTyID; }
221 
222   /// True if this is an instance of StructType.
isStructTy()223   bool isStructTy() const { return getTypeID() == StructTyID; }
224 
225   /// True if this is an instance of ArrayType.
isArrayTy()226   bool isArrayTy() const { return getTypeID() == ArrayTyID; }
227 
228   /// True if this is an instance of PointerType.
isPointerTy()229   bool isPointerTy() const { return getTypeID() == PointerTyID; }
230 
231   /// Return true if this is a pointer type or a vector of pointer types.
isPtrOrPtrVectorTy()232   bool isPtrOrPtrVectorTy() const { return getScalarType()->isPointerTy(); }
233 
234   /// True if this is an instance of VectorType.
isVectorTy()235   inline bool isVectorTy() const {
236     return getTypeID() == ScalableVectorTyID || getTypeID() == FixedVectorTyID;
237   }
238 
239   /// Return true if this type could be converted with a lossless BitCast to
240   /// type 'Ty'. For example, i8* to i32*. BitCasts are valid for types of the
241   /// same size only where no re-interpretation of the bits is done.
242   /// Determine if this type could be losslessly bitcast to Ty
243   bool canLosslesslyBitCastTo(Type *Ty) const;
244 
245   /// Return true if this type is empty, that is, it has no elements or all of
246   /// its elements are empty.
247   bool isEmptyTy() const;
248 
249   /// Return true if the type is "first class", meaning it is a valid type for a
250   /// Value.
isFirstClassType()251   bool isFirstClassType() const {
252     return getTypeID() != FunctionTyID && getTypeID() != VoidTyID;
253   }
254 
255   /// Return true if the type is a valid type for a register in codegen. This
256   /// includes all first-class types except struct and array types.
isSingleValueType()257   bool isSingleValueType() const {
258     return isFloatingPointTy() || isX86_MMXTy() || isIntegerTy() ||
259            isPointerTy() || isVectorTy() || isX86_AMXTy();
260   }
261 
262   /// Return true if the type is an aggregate type. This means it is valid as
263   /// the first operand of an insertvalue or extractvalue instruction. This
264   /// includes struct and array types, but does not include vector types.
isAggregateType()265   bool isAggregateType() const {
266     return getTypeID() == StructTyID || getTypeID() == ArrayTyID;
267   }
268 
269   /// Return true if it makes sense to take the size of this type. To get the
270   /// actual size for a particular target, it is reasonable to use the
271   /// DataLayout subsystem to do this.
272   bool isSized(SmallPtrSetImpl<Type*> *Visited = nullptr) const {
273     // If it's a primitive, it is always sized.
274     if (getTypeID() == IntegerTyID || isFloatingPointTy() ||
275         getTypeID() == PointerTyID || getTypeID() == X86_MMXTyID ||
276         getTypeID() == X86_AMXTyID)
277       return true;
278     // If it is not something that can have a size (e.g. a function or label),
279     // it doesn't have a size.
280     if (getTypeID() != StructTyID && getTypeID() != ArrayTyID && !isVectorTy())
281       return false;
282     // Otherwise we have to try harder to decide.
283     return isSizedDerivedType(Visited);
284   }
285 
286   /// Return the basic size of this type if it is a primitive type. These are
287   /// fixed by LLVM and are not target-dependent.
288   /// This will return zero if the type does not have a size or is not a
289   /// primitive type.
290   ///
291   /// If this is a scalable vector type, the scalable property will be set and
292   /// the runtime size will be a positive integer multiple of the base size.
293   ///
294   /// Note that this may not reflect the size of memory allocated for an
295   /// instance of the type or the number of bytes that are written when an
296   /// instance of the type is stored to memory. The DataLayout class provides
297   /// additional query functions to provide this information.
298   ///
299   TypeSize getPrimitiveSizeInBits() const LLVM_READONLY;
300 
301   /// If this is a vector type, return the getPrimitiveSizeInBits value for the
302   /// element type. Otherwise return the getPrimitiveSizeInBits value for this
303   /// type.
304   unsigned getScalarSizeInBits() const LLVM_READONLY;
305 
306   /// Return the width of the mantissa of this type. This is only valid on
307   /// floating-point types. If the FP type does not have a stable mantissa (e.g.
308   /// ppc long double), this method returns -1.
309   int getFPMantissaWidth() const;
310 
311   /// Return whether the type is IEEE compatible, as defined by the eponymous
312   /// method in APFloat.
isIEEE()313   bool isIEEE() const { return APFloat::getZero(getFltSemantics()).isIEEE(); }
314 
315   /// If this is a vector type, return the element type, otherwise return
316   /// 'this'.
getScalarType()317   inline Type *getScalarType() const {
318     if (isVectorTy())
319       return getContainedType(0);
320     return const_cast<Type *>(this);
321   }
322 
323   //===--------------------------------------------------------------------===//
324   // Type Iteration support.
325   //
326   using subtype_iterator = Type * const *;
327 
subtype_begin()328   subtype_iterator subtype_begin() const { return ContainedTys; }
subtype_end()329   subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
subtypes()330   ArrayRef<Type*> subtypes() const {
331     return makeArrayRef(subtype_begin(), subtype_end());
332   }
333 
334   using subtype_reverse_iterator = std::reverse_iterator<subtype_iterator>;
335 
subtype_rbegin()336   subtype_reverse_iterator subtype_rbegin() const {
337     return subtype_reverse_iterator(subtype_end());
338   }
subtype_rend()339   subtype_reverse_iterator subtype_rend() const {
340     return subtype_reverse_iterator(subtype_begin());
341   }
342 
343   /// This method is used to implement the type iterator (defined at the end of
344   /// the file). For derived types, this returns the types 'contained' in the
345   /// derived type.
getContainedType(unsigned i)346   Type *getContainedType(unsigned i) const {
347     assert(i < NumContainedTys && "Index out of range!");
348     return ContainedTys[i];
349   }
350 
351   /// Return the number of types in the derived type.
getNumContainedTypes()352   unsigned getNumContainedTypes() const { return NumContainedTys; }
353 
354   //===--------------------------------------------------------------------===//
355   // Helper methods corresponding to subclass methods.  This forces a cast to
356   // the specified subclass and calls its accessor.  "getArrayNumElements" (for
357   // example) is shorthand for cast<ArrayType>(Ty)->getNumElements().  This is
358   // only intended to cover the core methods that are frequently used, helper
359   // methods should not be added here.
360 
361   inline unsigned getIntegerBitWidth() const;
362 
363   inline Type *getFunctionParamType(unsigned i) const;
364   inline unsigned getFunctionNumParams() const;
365   inline bool isFunctionVarArg() const;
366 
367   inline StringRef getStructName() const;
368   inline unsigned getStructNumElements() const;
369   inline Type *getStructElementType(unsigned N) const;
370 
371   inline uint64_t getArrayNumElements() const;
372 
getArrayElementType()373   Type *getArrayElementType() const {
374     assert(getTypeID() == ArrayTyID);
375     return ContainedTys[0];
376   }
377 
getPointerElementType()378   Type *getPointerElementType() const {
379     assert(getTypeID() == PointerTyID);
380     return ContainedTys[0];
381   }
382 
383   /// Given vector type, change the element type,
384   /// whilst keeping the old number of elements.
385   /// For non-vectors simply returns \p EltTy.
386   inline Type *getWithNewType(Type *EltTy) const;
387 
388   /// Given an integer or vector type, change the lane bitwidth to NewBitwidth,
389   /// whilst keeping the old number of lanes.
390   inline Type *getWithNewBitWidth(unsigned NewBitWidth) const;
391 
392   /// Given scalar/vector integer type, returns a type with elements twice as
393   /// wide as in the original type. For vectors, preserves element count.
394   inline Type *getExtendedType() const;
395 
396   /// Get the address space of this pointer or pointer vector type.
397   inline unsigned getPointerAddressSpace() const;
398 
399   //===--------------------------------------------------------------------===//
400   // Static members exported by the Type class itself.  Useful for getting
401   // instances of Type.
402   //
403 
404   /// Return a type based on an identifier.
405   static Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber);
406 
407   //===--------------------------------------------------------------------===//
408   // These are the builtin types that are always available.
409   //
410   static Type *getVoidTy(LLVMContext &C);
411   static Type *getLabelTy(LLVMContext &C);
412   static Type *getHalfTy(LLVMContext &C);
413   static Type *getBFloatTy(LLVMContext &C);
414   static Type *getFloatTy(LLVMContext &C);
415   static Type *getDoubleTy(LLVMContext &C);
416   static Type *getMetadataTy(LLVMContext &C);
417   static Type *getX86_FP80Ty(LLVMContext &C);
418   static Type *getFP128Ty(LLVMContext &C);
419   static Type *getPPC_FP128Ty(LLVMContext &C);
420   static Type *getX86_MMXTy(LLVMContext &C);
421   static Type *getX86_AMXTy(LLVMContext &C);
422   static Type *getTokenTy(LLVMContext &C);
423   static IntegerType *getIntNTy(LLVMContext &C, unsigned N);
424   static IntegerType *getInt1Ty(LLVMContext &C);
425   static IntegerType *getInt8Ty(LLVMContext &C);
426   static IntegerType *getInt16Ty(LLVMContext &C);
427   static IntegerType *getInt32Ty(LLVMContext &C);
428   static IntegerType *getInt64Ty(LLVMContext &C);
429   static IntegerType *getInt128Ty(LLVMContext &C);
getScalarTy(LLVMContext & C)430   template <typename ScalarTy> static Type *getScalarTy(LLVMContext &C) {
431     int noOfBits = sizeof(ScalarTy) * CHAR_BIT;
432     if (std::is_integral<ScalarTy>::value) {
433       return (Type*) Type::getIntNTy(C, noOfBits);
434     } else if (std::is_floating_point<ScalarTy>::value) {
435       switch (noOfBits) {
436       case 32:
437         return Type::getFloatTy(C);
438       case 64:
439         return Type::getDoubleTy(C);
440       }
441     }
442     llvm_unreachable("Unsupported type in Type::getScalarTy");
443   }
getFloatingPointTy(LLVMContext & C,const fltSemantics & S)444   static Type *getFloatingPointTy(LLVMContext &C, const fltSemantics &S) {
445     Type *Ty;
446     if (&S == &APFloat::IEEEhalf())
447       Ty = Type::getHalfTy(C);
448     else if (&S == &APFloat::BFloat())
449       Ty = Type::getBFloatTy(C);
450     else if (&S == &APFloat::IEEEsingle())
451       Ty = Type::getFloatTy(C);
452     else if (&S == &APFloat::IEEEdouble())
453       Ty = Type::getDoubleTy(C);
454     else if (&S == &APFloat::x87DoubleExtended())
455       Ty = Type::getX86_FP80Ty(C);
456     else if (&S == &APFloat::IEEEquad())
457       Ty = Type::getFP128Ty(C);
458     else {
459       assert(&S == &APFloat::PPCDoubleDouble() && "Unknown FP format");
460       Ty = Type::getPPC_FP128Ty(C);
461     }
462     return Ty;
463   }
464 
465   //===--------------------------------------------------------------------===//
466   // Convenience methods for getting pointer types with one of the above builtin
467   // types as pointee.
468   //
469   static PointerType *getHalfPtrTy(LLVMContext &C, unsigned AS = 0);
470   static PointerType *getBFloatPtrTy(LLVMContext &C, unsigned AS = 0);
471   static PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0);
472   static PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0);
473   static PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0);
474   static PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0);
475   static PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0);
476   static PointerType *getX86_MMXPtrTy(LLVMContext &C, unsigned AS = 0);
477   static PointerType *getX86_AMXPtrTy(LLVMContext &C, unsigned AS = 0);
478   static PointerType *getIntNPtrTy(LLVMContext &C, unsigned N, unsigned AS = 0);
479   static PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0);
480   static PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
481   static PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0);
482   static PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0);
483   static PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0);
484 
485   /// Return a pointer to the current type. This is equivalent to
486   /// PointerType::get(Foo, AddrSpace).
487   PointerType *getPointerTo(unsigned AddrSpace = 0) const;
488 
489 private:
490   /// Derived types like structures and arrays are sized iff all of the members
491   /// of the type are sized as well. Since asking for their size is relatively
492   /// uncommon, move this operation out-of-line.
493   bool isSizedDerivedType(SmallPtrSetImpl<Type*> *Visited = nullptr) const;
494 };
495 
496 // Printing of types.
497 inline raw_ostream &operator<<(raw_ostream &OS, const Type &T) {
498   T.print(OS);
499   return OS;
500 }
501 
502 // allow isa<PointerType>(x) to work without DerivedTypes.h included.
503 template <> struct isa_impl<PointerType, Type> {
504   static inline bool doit(const Type &Ty) {
505     return Ty.getTypeID() == Type::PointerTyID;
506   }
507 };
508 
509 // Create wrappers for C Binding types (see CBindingWrapping.h).
510 DEFINE_ISA_CONVERSION_FUNCTIONS(Type, LLVMTypeRef)
511 
512 /* Specialized opaque type conversions.
513  */
514 inline Type **unwrap(LLVMTypeRef* Tys) {
515   return reinterpret_cast<Type**>(Tys);
516 }
517 
518 inline LLVMTypeRef *wrap(Type **Tys) {
519   return reinterpret_cast<LLVMTypeRef*>(const_cast<Type**>(Tys));
520 }
521 
522 } // end namespace llvm
523 
524 #endif // LLVM_IR_TYPE_H
525