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/ArrayRef.h"
18 #include "llvm/Support/CBindingWrapping.h"
19 #include "llvm/Support/Casting.h"
20 #include "llvm/Support/Compiler.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/TypeSize.h"
23 #include <cassert>
24 #include <cstdint>
25 #include <iterator>
26 
27 namespace llvm {
28 
29 class IntegerType;
30 struct fltSemantics;
31 class LLVMContext;
32 class PointerType;
33 class raw_ostream;
34 class StringRef;
35 template <typename PtrType> class SmallPtrSetImpl;
36 
37 /// The instances of the Type class are immutable: once they are created,
38 /// they are never changed.  Also note that only one instance of a particular
39 /// type is ever created.  Thus seeing if two types are equal is a matter of
40 /// doing a trivial pointer comparison. To enforce that no two equal instances
41 /// are created, Type instances can only be created via static factory methods
42 /// in class Type and in derived classes.  Once allocated, Types are never
43 /// free'd.
44 ///
45 class Type {
46 public:
47   //===--------------------------------------------------------------------===//
48   /// Definitions of all of the base types for the Type system.  Based on this
49   /// value, you can cast to a class defined in DerivedTypes.h.
50   /// Note: If you add an element to this, you need to add an element to the
51   /// Type::getPrimitiveType function, or else things will break!
52   /// Also update LLVMTypeKind and LLVMGetTypeKind () in the C binding.
53   ///
54   enum TypeID {
55     // PrimitiveTypes
56     HalfTyID = 0,  ///< 16-bit floating point type
57     BFloatTyID,    ///< 16-bit floating point type (7-bit significand)
58     FloatTyID,     ///< 32-bit floating point type
59     DoubleTyID,    ///< 64-bit floating point type
60     X86_FP80TyID,  ///< 80-bit floating point type (X87)
61     FP128TyID,     ///< 128-bit floating point type (112-bit significand)
62     PPC_FP128TyID, ///< 128-bit floating point type (two 64-bits, PowerPC)
63     VoidTyID,      ///< type with no size
64     LabelTyID,     ///< Labels
65     MetadataTyID,  ///< Metadata
66     X86_MMXTyID,   ///< MMX vectors (64 bits, X86 specific)
67     X86_AMXTyID,   ///< AMX vectors (8192 bits, X86 specific)
68     TokenTyID,     ///< Tokens
69 
70     // Derived types... see DerivedTypes.h file.
71     IntegerTyID,        ///< Arbitrary bit width integers
72     FunctionTyID,       ///< Functions
73     PointerTyID,        ///< Pointers
74     StructTyID,         ///< Structures
75     ArrayTyID,          ///< Arrays
76     FixedVectorTyID,    ///< Fixed width SIMD vector type
77     ScalableVectorTyID, ///< Scalable SIMD vector type
78     TypedPointerTyID,   ///< Typed pointer used by some GPU targets
79     TargetExtTyID,      ///< Target extension type
80   };
81 
82 private:
83   /// This refers to the LLVMContext in which this type was uniqued.
84   LLVMContext &Context;
85 
86   TypeID   ID : 8;            // The current base type of this type.
87   unsigned SubclassData : 24; // Space for subclasses to store data.
88                               // Note that this should be synchronized with
89                               // MAX_INT_BITS value in IntegerType class.
90 
91 protected:
92   friend class LLVMContextImpl;
93 
Type(LLVMContext & C,TypeID tid)94   explicit Type(LLVMContext &C, TypeID tid)
95     : Context(C), ID(tid), SubclassData(0) {}
96   ~Type() = default;
97 
getSubclassData()98   unsigned getSubclassData() const { return SubclassData; }
99 
setSubclassData(unsigned val)100   void setSubclassData(unsigned val) {
101     SubclassData = val;
102     // Ensure we don't have any accidental truncation.
103     assert(getSubclassData() == val && "Subclass data too large for field");
104   }
105 
106   /// Keeps track of how many Type*'s there are in the ContainedTys list.
107   unsigned NumContainedTys = 0;
108 
109   /// A pointer to the array of Types contained by this Type. For example, this
110   /// includes the arguments of a function type, the elements of a structure,
111   /// the pointee of a pointer, the element type of an array, etc. This pointer
112   /// may be 0 for types that don't contain other types (Integer, Double,
113   /// Float).
114   Type * const *ContainedTys = nullptr;
115 
116 public:
117   /// Print the current type.
118   /// Omit the type details if \p NoDetails == true.
119   /// E.g., let %st = type { i32, i16 }
120   /// When \p NoDetails is true, we only print %st.
121   /// Put differently, \p NoDetails prints the type as if
122   /// inlined with the operands when printing an instruction.
123   void print(raw_ostream &O, bool IsForDebug = false,
124              bool NoDetails = false) const;
125 
126   void dump() const;
127 
128   /// Return the LLVMContext in which this type was uniqued.
getContext()129   LLVMContext &getContext() const { return Context; }
130 
131   //===--------------------------------------------------------------------===//
132   // Accessors for working with types.
133   //
134 
135   /// Return the type id for the type. This will return one of the TypeID enum
136   /// elements defined above.
getTypeID()137   TypeID getTypeID() const { return ID; }
138 
139   /// Return true if this is 'void'.
isVoidTy()140   bool isVoidTy() const { return getTypeID() == VoidTyID; }
141 
142   /// Return true if this is 'half', a 16-bit IEEE fp type.
isHalfTy()143   bool isHalfTy() const { return getTypeID() == HalfTyID; }
144 
145   /// Return true if this is 'bfloat', a 16-bit bfloat type.
isBFloatTy()146   bool isBFloatTy() const { return getTypeID() == BFloatTyID; }
147 
148   /// Return true if this is a 16-bit float type.
is16bitFPTy()149   bool is16bitFPTy() const {
150     return getTypeID() == BFloatTyID || getTypeID() == HalfTyID;
151   }
152 
153   /// Return true if this is 'float', a 32-bit IEEE fp type.
isFloatTy()154   bool isFloatTy() const { return getTypeID() == FloatTyID; }
155 
156   /// Return true if this is 'double', a 64-bit IEEE fp type.
isDoubleTy()157   bool isDoubleTy() const { return getTypeID() == DoubleTyID; }
158 
159   /// Return true if this is x86 long double.
isX86_FP80Ty()160   bool isX86_FP80Ty() const { return getTypeID() == X86_FP80TyID; }
161 
162   /// Return true if this is 'fp128'.
isFP128Ty()163   bool isFP128Ty() const { return getTypeID() == FP128TyID; }
164 
165   /// Return true if this is powerpc long double.
isPPC_FP128Ty()166   bool isPPC_FP128Ty() const { return getTypeID() == PPC_FP128TyID; }
167 
168   /// Return true if this is a well-behaved IEEE-like type, which has a IEEE
169   /// compatible layout as defined by APFloat::isIEEE(), and does not have
170   /// non-IEEE values, such as x86_fp80's unnormal values.
isIEEELikeFPTy()171   bool isIEEELikeFPTy() const {
172     switch (getTypeID()) {
173     case DoubleTyID:
174     case FloatTyID:
175     case HalfTyID:
176     case BFloatTyID:
177     case FP128TyID:
178       return true;
179     default:
180       return false;
181     }
182   }
183 
184   /// Return true if this is one of the floating-point types
isFloatingPointTy()185   bool isFloatingPointTy() const {
186     return isIEEELikeFPTy() || getTypeID() == X86_FP80TyID ||
187            getTypeID() == PPC_FP128TyID;
188   }
189 
190   /// Returns true if this is a floating-point type that is an unevaluated sum
191   /// of multiple floating-point units.
192   /// An example of such a type is ppc_fp128, also known as double-double, which
193   /// consists of two IEEE 754 doubles.
isMultiUnitFPType()194   bool isMultiUnitFPType() const {
195     return getTypeID() == PPC_FP128TyID;
196   }
197 
198   const fltSemantics &getFltSemantics() const;
199 
200   /// Return true if this is X86 MMX.
isX86_MMXTy()201   bool isX86_MMXTy() const { return getTypeID() == X86_MMXTyID; }
202 
203   /// Return true if this is X86 AMX.
isX86_AMXTy()204   bool isX86_AMXTy() const { return getTypeID() == X86_AMXTyID; }
205 
206   /// Return true if this is a target extension type.
isTargetExtTy()207   bool isTargetExtTy() const { return getTypeID() == TargetExtTyID; }
208 
209   /// Return true if this is a target extension type with a scalable layout.
210   bool isScalableTargetExtTy() const;
211 
212   /// Return true if this is a type whose size is a known multiple of vscale.
213   bool isScalableTy() const;
214 
215   /// Return true if this is a FP type or a vector of FP.
isFPOrFPVectorTy()216   bool isFPOrFPVectorTy() const { return getScalarType()->isFloatingPointTy(); }
217 
218   /// Return true if this is 'label'.
isLabelTy()219   bool isLabelTy() const { return getTypeID() == LabelTyID; }
220 
221   /// Return true if this is 'metadata'.
isMetadataTy()222   bool isMetadataTy() const { return getTypeID() == MetadataTyID; }
223 
224   /// Return true if this is 'token'.
isTokenTy()225   bool isTokenTy() const { return getTypeID() == TokenTyID; }
226 
227   /// True if this is an instance of IntegerType.
isIntegerTy()228   bool isIntegerTy() const { return getTypeID() == IntegerTyID; }
229 
230   /// Return true if this is an IntegerType of the given width.
231   bool isIntegerTy(unsigned Bitwidth) const;
232 
233   /// Return true if this is an integer type or a vector of integer types.
isIntOrIntVectorTy()234   bool isIntOrIntVectorTy() const { return getScalarType()->isIntegerTy(); }
235 
236   /// Return true if this is an integer type or a vector of integer types of
237   /// the given width.
isIntOrIntVectorTy(unsigned BitWidth)238   bool isIntOrIntVectorTy(unsigned BitWidth) const {
239     return getScalarType()->isIntegerTy(BitWidth);
240   }
241 
242   /// Return true if this is an integer type or a pointer type.
isIntOrPtrTy()243   bool isIntOrPtrTy() const { return isIntegerTy() || isPointerTy(); }
244 
245   /// True if this is an instance of FunctionType.
isFunctionTy()246   bool isFunctionTy() const { return getTypeID() == FunctionTyID; }
247 
248   /// True if this is an instance of StructType.
isStructTy()249   bool isStructTy() const { return getTypeID() == StructTyID; }
250 
251   /// True if this is an instance of ArrayType.
isArrayTy()252   bool isArrayTy() const { return getTypeID() == ArrayTyID; }
253 
254   /// True if this is an instance of PointerType.
isPointerTy()255   bool isPointerTy() const { return getTypeID() == PointerTyID; }
256 
257   /// True if this is an instance of an opaque PointerType.
258   LLVM_DEPRECATED("Use isPointerTy() instead", "isPointerTy")
isOpaquePointerTy()259   bool isOpaquePointerTy() const { return isPointerTy(); };
260 
261   /// Return true if this is a pointer type or a vector of pointer types.
isPtrOrPtrVectorTy()262   bool isPtrOrPtrVectorTy() const { return getScalarType()->isPointerTy(); }
263 
264   /// True if this is an instance of VectorType.
isVectorTy()265   inline bool isVectorTy() const {
266     return getTypeID() == ScalableVectorTyID || getTypeID() == FixedVectorTyID;
267   }
268 
269   /// Return true if this type could be converted with a lossless BitCast to
270   /// type 'Ty'. For example, i8* to i32*. BitCasts are valid for types of the
271   /// same size only where no re-interpretation of the bits is done.
272   /// Determine if this type could be losslessly bitcast to Ty
273   bool canLosslesslyBitCastTo(Type *Ty) const;
274 
275   /// Return true if this type is empty, that is, it has no elements or all of
276   /// its elements are empty.
277   bool isEmptyTy() const;
278 
279   /// Return true if the type is "first class", meaning it is a valid type for a
280   /// Value.
isFirstClassType()281   bool isFirstClassType() const {
282     return getTypeID() != FunctionTyID && getTypeID() != VoidTyID;
283   }
284 
285   /// Return true if the type is a valid type for a register in codegen. This
286   /// includes all first-class types except struct and array types.
isSingleValueType()287   bool isSingleValueType() const {
288     return isFloatingPointTy() || isX86_MMXTy() || isIntegerTy() ||
289            isPointerTy() || isVectorTy() || isX86_AMXTy() || isTargetExtTy();
290   }
291 
292   /// Return true if the type is an aggregate type. This means it is valid as
293   /// the first operand of an insertvalue or extractvalue instruction. This
294   /// includes struct and array types, but does not include vector types.
isAggregateType()295   bool isAggregateType() const {
296     return getTypeID() == StructTyID || getTypeID() == ArrayTyID;
297   }
298 
299   /// Return true if it makes sense to take the size of this type. To get the
300   /// actual size for a particular target, it is reasonable to use the
301   /// DataLayout subsystem to do this.
302   bool isSized(SmallPtrSetImpl<Type*> *Visited = nullptr) const {
303     // If it's a primitive, it is always sized.
304     if (getTypeID() == IntegerTyID || isFloatingPointTy() ||
305         getTypeID() == PointerTyID || getTypeID() == X86_MMXTyID ||
306         getTypeID() == X86_AMXTyID)
307       return true;
308     // If it is not something that can have a size (e.g. a function or label),
309     // it doesn't have a size.
310     if (getTypeID() != StructTyID && getTypeID() != ArrayTyID &&
311         !isVectorTy() && getTypeID() != TargetExtTyID)
312       return false;
313     // Otherwise we have to try harder to decide.
314     return isSizedDerivedType(Visited);
315   }
316 
317   /// Return the basic size of this type if it is a primitive type. These are
318   /// fixed by LLVM and are not target-dependent.
319   /// This will return zero if the type does not have a size or is not a
320   /// primitive type.
321   ///
322   /// If this is a scalable vector type, the scalable property will be set and
323   /// the runtime size will be a positive integer multiple of the base size.
324   ///
325   /// Note that this may not reflect the size of memory allocated for an
326   /// instance of the type or the number of bytes that are written when an
327   /// instance of the type is stored to memory. The DataLayout class provides
328   /// additional query functions to provide this information.
329   ///
330   TypeSize getPrimitiveSizeInBits() const LLVM_READONLY;
331 
332   /// If this is a vector type, return the getPrimitiveSizeInBits value for the
333   /// element type. Otherwise return the getPrimitiveSizeInBits value for this
334   /// type.
335   unsigned getScalarSizeInBits() const LLVM_READONLY;
336 
337   /// Return the width of the mantissa of this type. This is only valid on
338   /// floating-point types. If the FP type does not have a stable mantissa (e.g.
339   /// ppc long double), this method returns -1.
340   int getFPMantissaWidth() const;
341 
342   /// Return whether the type is IEEE compatible, as defined by the eponymous
343   /// method in APFloat.
344   bool isIEEE() const;
345 
346   /// If this is a vector type, return the element type, otherwise return
347   /// 'this'.
getScalarType()348   inline Type *getScalarType() const {
349     if (isVectorTy())
350       return getContainedType(0);
351     return const_cast<Type *>(this);
352   }
353 
354   //===--------------------------------------------------------------------===//
355   // Type Iteration support.
356   //
357   using subtype_iterator = Type * const *;
358 
subtype_begin()359   subtype_iterator subtype_begin() const { return ContainedTys; }
subtype_end()360   subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
subtypes()361   ArrayRef<Type*> subtypes() const {
362     return ArrayRef(subtype_begin(), subtype_end());
363   }
364 
365   using subtype_reverse_iterator = std::reverse_iterator<subtype_iterator>;
366 
subtype_rbegin()367   subtype_reverse_iterator subtype_rbegin() const {
368     return subtype_reverse_iterator(subtype_end());
369   }
subtype_rend()370   subtype_reverse_iterator subtype_rend() const {
371     return subtype_reverse_iterator(subtype_begin());
372   }
373 
374   /// This method is used to implement the type iterator (defined at the end of
375   /// the file). For derived types, this returns the types 'contained' in the
376   /// derived type.
getContainedType(unsigned i)377   Type *getContainedType(unsigned i) const {
378     assert(i < NumContainedTys && "Index out of range!");
379     return ContainedTys[i];
380   }
381 
382   /// Return the number of types in the derived type.
getNumContainedTypes()383   unsigned getNumContainedTypes() const { return NumContainedTys; }
384 
385   //===--------------------------------------------------------------------===//
386   // Helper methods corresponding to subclass methods.  This forces a cast to
387   // the specified subclass and calls its accessor.  "getArrayNumElements" (for
388   // example) is shorthand for cast<ArrayType>(Ty)->getNumElements().  This is
389   // only intended to cover the core methods that are frequently used, helper
390   // methods should not be added here.
391 
392   inline unsigned getIntegerBitWidth() const;
393 
394   inline Type *getFunctionParamType(unsigned i) const;
395   inline unsigned getFunctionNumParams() const;
396   inline bool isFunctionVarArg() const;
397 
398   inline StringRef getStructName() const;
399   inline unsigned getStructNumElements() const;
400   inline Type *getStructElementType(unsigned N) const;
401 
402   inline uint64_t getArrayNumElements() const;
403 
getArrayElementType()404   Type *getArrayElementType() const {
405     assert(getTypeID() == ArrayTyID);
406     return ContainedTys[0];
407   }
408 
409   inline StringRef getTargetExtName() const;
410 
411   /// Only use this method in code that is not reachable with opaque pointers,
412   /// or part of deprecated methods that will be removed as part of the opaque
413   /// pointers transition.
414   [[deprecated("Pointers no longer have element types")]]
getNonOpaquePointerElementType()415   Type *getNonOpaquePointerElementType() const {
416     llvm_unreachable("Pointers no longer have element types");
417   }
418 
419   /// Given vector type, change the element type,
420   /// whilst keeping the old number of elements.
421   /// For non-vectors simply returns \p EltTy.
422   inline Type *getWithNewType(Type *EltTy) const;
423 
424   /// Given an integer or vector type, change the lane bitwidth to NewBitwidth,
425   /// whilst keeping the old number of lanes.
426   inline Type *getWithNewBitWidth(unsigned NewBitWidth) const;
427 
428   /// Given scalar/vector integer type, returns a type with elements twice as
429   /// wide as in the original type. For vectors, preserves element count.
430   inline Type *getExtendedType() const;
431 
432   /// Get the address space of this pointer or pointer vector type.
433   inline unsigned getPointerAddressSpace() const;
434 
435   //===--------------------------------------------------------------------===//
436   // Static members exported by the Type class itself.  Useful for getting
437   // instances of Type.
438   //
439 
440   /// Return a type based on an identifier.
441   static Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber);
442 
443   //===--------------------------------------------------------------------===//
444   // These are the builtin types that are always available.
445   //
446   static Type *getVoidTy(LLVMContext &C);
447   static Type *getLabelTy(LLVMContext &C);
448   static Type *getHalfTy(LLVMContext &C);
449   static Type *getBFloatTy(LLVMContext &C);
450   static Type *getFloatTy(LLVMContext &C);
451   static Type *getDoubleTy(LLVMContext &C);
452   static Type *getMetadataTy(LLVMContext &C);
453   static Type *getX86_FP80Ty(LLVMContext &C);
454   static Type *getFP128Ty(LLVMContext &C);
455   static Type *getPPC_FP128Ty(LLVMContext &C);
456   static Type *getX86_MMXTy(LLVMContext &C);
457   static Type *getX86_AMXTy(LLVMContext &C);
458   static Type *getTokenTy(LLVMContext &C);
459   static IntegerType *getIntNTy(LLVMContext &C, unsigned N);
460   static IntegerType *getInt1Ty(LLVMContext &C);
461   static IntegerType *getInt8Ty(LLVMContext &C);
462   static IntegerType *getInt16Ty(LLVMContext &C);
463   static IntegerType *getInt32Ty(LLVMContext &C);
464   static IntegerType *getInt64Ty(LLVMContext &C);
465   static IntegerType *getInt128Ty(LLVMContext &C);
getScalarTy(LLVMContext & C)466   template <typename ScalarTy> static Type *getScalarTy(LLVMContext &C) {
467     int noOfBits = sizeof(ScalarTy) * CHAR_BIT;
468     if (std::is_integral<ScalarTy>::value) {
469       return (Type*) Type::getIntNTy(C, noOfBits);
470     } else if (std::is_floating_point<ScalarTy>::value) {
471       switch (noOfBits) {
472       case 32:
473         return Type::getFloatTy(C);
474       case 64:
475         return Type::getDoubleTy(C);
476       }
477     }
478     llvm_unreachable("Unsupported type in Type::getScalarTy");
479   }
480   static Type *getFloatingPointTy(LLVMContext &C, const fltSemantics &S);
481 
482   //===--------------------------------------------------------------------===//
483   // Convenience methods for getting pointer types.
484   //
485   static Type *getWasm_ExternrefTy(LLVMContext &C);
486   static Type *getWasm_FuncrefTy(LLVMContext &C);
487 
488   /// Return a pointer to the current type. This is equivalent to
489   /// PointerType::get(Foo, AddrSpace).
490   /// TODO: Remove this after opaque pointer transition is complete.
491   PointerType *getPointerTo(unsigned AddrSpace = 0) const;
492 
493 private:
494   /// Derived types like structures and arrays are sized iff all of the members
495   /// of the type are sized as well. Since asking for their size is relatively
496   /// uncommon, move this operation out-of-line.
497   bool isSizedDerivedType(SmallPtrSetImpl<Type*> *Visited = nullptr) const;
498 };
499 
500 // Printing of types.
501 inline raw_ostream &operator<<(raw_ostream &OS, const Type &T) {
502   T.print(OS);
503   return OS;
504 }
505 
506 // allow isa<PointerType>(x) to work without DerivedTypes.h included.
507 template <> struct isa_impl<PointerType, Type> {
508   static inline bool doit(const Type &Ty) {
509     return Ty.getTypeID() == Type::PointerTyID;
510   }
511 };
512 
513 // Create wrappers for C Binding types (see CBindingWrapping.h).
514 DEFINE_ISA_CONVERSION_FUNCTIONS(Type, LLVMTypeRef)
515 
516 /* Specialized opaque type conversions.
517  */
518 inline Type **unwrap(LLVMTypeRef* Tys) {
519   return reinterpret_cast<Type**>(Tys);
520 }
521 
522 inline LLVMTypeRef *wrap(Type **Tys) {
523   return reinterpret_cast<LLVMTypeRef*>(const_cast<Type**>(Tys));
524 }
525 
526 } // end namespace llvm
527 
528 #endif // LLVM_IR_TYPE_H
529