include/llvm/IR/Type.h

   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 <cassert>
  25 #include <cstdint>
  26 #include <iterator>
  27
  28 namespace llvm {
  29
  30 template<class GraphType> struct GraphTraits;
  31 class IntegerType;
  32 class LLVMContext;
  33 class PointerType;
  34 class raw_ostream;
  35 class StringRef;
  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 - make sure LastPrimitiveTyID stays up to date.
  56     VoidTyID = 0,    ///<  0: type with no size
  57     HalfTyID,        ///<  1: 16-bit floating point type
  58     FloatTyID,       ///<  2: 32-bit floating point type
  59     DoubleTyID,      ///<  3: 64-bit floating point type
  60     X86_FP80TyID,    ///<  4: 80-bit floating point type (X87)
  61     FP128TyID,       ///<  5: 128-bit floating point type (112-bit mantissa)
  62     PPC_FP128TyID,   ///<  6: 128-bit floating point type (two 64-bits, PowerPC)
  63     LabelTyID,       ///<  7: Labels
  64     MetadataTyID,    ///<  8: Metadata
  65     X86_MMXTyID,     ///<  9: MMX vectors (64 bits, X86 specific)
  66     TokenTyID,       ///< 10: Tokens
  67
  68     // Derived types... see DerivedTypes.h file.
  69     // Make sure FirstDerivedTyID stays up to date!
  70     IntegerTyID,     ///< 11: Arbitrary bit width integers
  71     FunctionTyID,    ///< 12: Functions
  72     StructTyID,      ///< 13: Structures
  73     ArrayTyID,       ///< 14: Arrays
  74     PointerTyID,     ///< 15: Pointers
  75     VectorTyID       ///< 16: SIMD 'packed' format, or other vector type
  76   };
  77
  78 private:
  79   /// This refers to the LLVMContext in which this type was uniqued.
  80   LLVMContext &Context;
  81
  82   TypeID   ID : 8;            // The current base type of this type.
  83   unsigned SubclassData : 24; // Space for subclasses to store data.
  84                               // Note that this should be synchronized with
  85                               // MAX_INT_BITS value in IntegerType class.
  86
  87 protected:
  88   friend class LLVMContextImpl;
  89
  90   explicit Type(LLVMContext &C, TypeID tid)
  91     : Context(C), ID(tid), SubclassData(0) {}
  92   ~Type() = default;
  93
  94   unsigned getSubclassData() const { return SubclassData; }
  95
  96   void setSubclassData(unsigned val) {
  97     SubclassData = val;
  98     // Ensure we don't have any accidental truncation.
  99     assert(getSubclassData() == val && "Subclass data too large for field");
 100   }
 101
 102   /// Keeps track of how many Type*'s there are in the ContainedTys list.
 103   unsigned NumContainedTys = 0;
 104
 105   /// A pointer to the array of Types contained by this Type. For example, this
 106   /// includes the arguments of a function type, the elements of a structure,
 107   /// the pointee of a pointer, the element type of an array, etc. This pointer
 108   /// may be 0 for types that don't contain other types (Integer, Double,
 109   /// Float).
 110   Type * const *ContainedTys = nullptr;
 111
 112   static bool isSequentialType(TypeID TyID) {
 113     return TyID == ArrayTyID || TyID == VectorTyID;
 114   }
 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.
 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.
 137   TypeID getTypeID() const { return ID; }
 138
 139   /// Return true if this is 'void'.
 140   bool isVoidTy() const { return getTypeID() == VoidTyID; }
 141
 142   /// Return true if this is 'half', a 16-bit IEEE fp type.
 143   bool isHalfTy() const { return getTypeID() == HalfTyID; }
 144
 145   /// Return true if this is 'float', a 32-bit IEEE fp type.
 146   bool isFloatTy() const { return getTypeID() == FloatTyID; }
 147
 148   /// Return true if this is 'double', a 64-bit IEEE fp type.
 149   bool isDoubleTy() const { return getTypeID() == DoubleTyID; }
 150
 151   /// Return true if this is x86 long double.
 152   bool isX86_FP80Ty() const { return getTypeID() == X86_FP80TyID; }
 153
 154   /// Return true if this is 'fp128'.
 155   bool isFP128Ty() const { return getTypeID() == FP128TyID; }
 156
 157   /// Return true if this is powerpc long double.
 158   bool isPPC_FP128Ty() const { return getTypeID() == PPC_FP128TyID; }
 159
 160   /// Return true if this is one of the six floating-point types
 161   bool isFloatingPointTy() const {
 162     return getTypeID() == HalfTyID || getTypeID() == FloatTyID ||
 163            getTypeID() == DoubleTyID ||
 164            getTypeID() == X86_FP80TyID || getTypeID() == FP128TyID ||
 165            getTypeID() == PPC_FP128TyID;
 166   }
 167
 168   const fltSemantics &getFltSemantics() const {
 169     switch (getTypeID()) {
 170     case HalfTyID: return APFloat::IEEEhalf();
 171     case FloatTyID: return APFloat::IEEEsingle();
 172     case DoubleTyID: return APFloat::IEEEdouble();
 173     case X86_FP80TyID: return APFloat::x87DoubleExtended();
 174     case FP128TyID: return APFloat::IEEEquad();
 175     case PPC_FP128TyID: return APFloat::PPCDoubleDouble();
 176     default: llvm_unreachable("Invalid floating type");
 177     }
 178   }
 179
 180   /// Return true if this is X86 MMX.
 181   bool isX86_MMXTy() const { return getTypeID() == X86_MMXTyID; }
 182
 183   /// Return true if this is a FP type or a vector of FP.
 184   bool isFPOrFPVectorTy() const { return getScalarType()->isFloatingPointTy(); }
 185
 186   /// Return true if this is 'label'.
 187   bool isLabelTy() const { return getTypeID() == LabelTyID; }
 188
 189   /// Return true if this is 'metadata'.
 190   bool isMetadataTy() const { return getTypeID() == MetadataTyID; }
 191
 192   /// Return true if this is 'token'.
 193   bool isTokenTy() const { return getTypeID() == TokenTyID; }
 194
 195   /// True if this is an instance of IntegerType.
 196   bool isIntegerTy() const { return getTypeID() == IntegerTyID; }
 197
 198   /// Return true if this is an IntegerType of the given width.
 199   bool isIntegerTy(unsigned Bitwidth) const;
 200
 201   /// Return true if this is an integer type or a vector of integer types.
 202   bool isIntOrIntVectorTy() const { return getScalarType()->isIntegerTy(); }
 203
 204   /// Return true if this is an integer type or a vector of integer types of
 205   /// the given width.
 206   bool isIntOrIntVectorTy(unsigned BitWidth) const {
 207     return getScalarType()->isIntegerTy(BitWidth);
 208   }
 209
 210   /// Return true if this is an integer type or a pointer type.
 211   bool isIntOrPtrTy() const { return isIntegerTy() || isPointerTy(); }
 212
 213   /// True if this is an instance of FunctionType.
 214   bool isFunctionTy() const { return getTypeID() == FunctionTyID; }
 215
 216   /// True if this is an instance of StructType.
 217   bool isStructTy() const { return getTypeID() == StructTyID; }
 218
 219   /// True if this is an instance of ArrayType.
 220   bool isArrayTy() const { return getTypeID() == ArrayTyID; }
 221
 222   /// True if this is an instance of PointerType.
 223   bool isPointerTy() const { return getTypeID() == PointerTyID; }
 224
 225   /// Return true if this is a pointer type or a vector of pointer types.
 226   bool isPtrOrPtrVectorTy() const { return getScalarType()->isPointerTy(); }
 227
 228   /// True if this is an instance of VectorType.
 229   bool isVectorTy() const { return getTypeID() == VectorTyID; }
 230
 231   /// Return true if this type could be converted with a lossless BitCast to
 232   /// type 'Ty'. For example, i8* to i32*. BitCasts are valid for types of the
 233   /// same size only where no re-interpretation of the bits is done.
 234   /// Determine if this type could be losslessly bitcast to Ty
 235   bool canLosslesslyBitCastTo(Type *Ty) const;
 236
 237   /// Return true if this type is empty, that is, it has no elements or all of
 238   /// its elements are empty.
 239   bool isEmptyTy() const;
 240
 241   /// Return true if the type is "first class", meaning it is a valid type for a
 242   /// Value.
 243   bool isFirstClassType() const {
 244     return getTypeID() != FunctionTyID && getTypeID() != VoidTyID;
 245   }
 246
 247   /// Return true if the type is a valid type for a register in codegen. This
 248   /// includes all first-class types except struct and array types.
 249   bool isSingleValueType() const {
 250     return isFloatingPointTy() || isX86_MMXTy() || isIntegerTy() ||
 251            isPointerTy() || isVectorTy();
 252   }
 253
 254   /// Return true if the type is an aggregate type. This means it is valid as
 255   /// the first operand of an insertvalue or extractvalue instruction. This
 256   /// includes struct and array types, but does not include vector types.
 257   bool isAggregateType() const {
 258     return getTypeID() == StructTyID || getTypeID() == ArrayTyID;
 259   }
 260
 261   /// Return true if it makes sense to take the size of this type. To get the
 262   /// actual size for a particular target, it is reasonable to use the
 263   /// DataLayout subsystem to do this.
 264   bool isSized(SmallPtrSetImpl<Type*> *Visited = nullptr) const {
 265     // If it's a primitive, it is always sized.
 266     if (getTypeID() == IntegerTyID || isFloatingPointTy() ||
 267         getTypeID() == PointerTyID ||
 268         getTypeID() == X86_MMXTyID)
 269       return true;
 270     // If it is not something that can have a size (e.g. a function or label),
 271     // it doesn't have a size.
 272     if (getTypeID() != StructTyID && getTypeID() != ArrayTyID &&
 273         getTypeID() != VectorTyID)
 274       return false;
 275     // Otherwise we have to try harder to decide.
 276     return isSizedDerivedType(Visited);
 277   }
 278
 279   /// Return the basic size of this type if it is a primitive type. These are
 280   /// fixed by LLVM and are not target-dependent.
 281   /// This will return zero if the type does not have a size or is not a
 282   /// primitive type.
 283   ///
 284   /// Note that this may not reflect the size of memory allocated for an
 285   /// instance of the type or the number of bytes that are written when an
 286   /// instance of the type is stored to memory. The DataLayout class provides
 287   /// additional query functions to provide this information.
 288   ///
 289   unsigned getPrimitiveSizeInBits() const LLVM_READONLY;
 290
 291   /// If this is a vector type, return the getPrimitiveSizeInBits value for the
 292   /// element type. Otherwise return the getPrimitiveSizeInBits value for this
 293   /// type.
 294   unsigned getScalarSizeInBits() const LLVM_READONLY;
 295
 296   /// Return the width of the mantissa of this type. This is only valid on
 297   /// floating-point types. If the FP type does not have a stable mantissa (e.g.
 298   /// ppc long double), this method returns -1.
 299   int getFPMantissaWidth() const;
 300
 301   /// If this is a vector type, return the element type, otherwise return
 302   /// 'this'.
 303   Type *getScalarType() const {
 304     if (isVectorTy())
 305       return getVectorElementType();
 306     return const_cast<Type*>(this);
 307   }
 308
 309   //===--------------------------------------------------------------------===//
 310   // Type Iteration support.
 311   //
 312   using subtype_iterator = Type * const *;
 313
 314   subtype_iterator subtype_begin() const { return ContainedTys; }
 315   subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
 316   ArrayRef<Type*> subtypes() const {
 317     return makeArrayRef(subtype_begin(), subtype_end());
 318   }
 319
 320   using subtype_reverse_iterator = std::reverse_iterator<subtype_iterator>;
 321
 322   subtype_reverse_iterator subtype_rbegin() const {
 323     return subtype_reverse_iterator(subtype_end());
 324   }
 325   subtype_reverse_iterator subtype_rend() const {
 326     return subtype_reverse_iterator(subtype_begin());
 327   }
 328
 329   /// This method is used to implement the type iterator (defined at the end of
 330   /// the file). For derived types, this returns the types 'contained' in the
 331   /// derived type.
 332   Type *getContainedType(unsigned i) const {
 333     assert(i < NumContainedTys && "Index out of range!");
 334     return ContainedTys[i];
 335   }
 336
 337   /// Return the number of types in the derived type.
 338   unsigned getNumContainedTypes() const { return NumContainedTys; }
 339
 340   //===--------------------------------------------------------------------===//
 341   // Helper methods corresponding to subclass methods.  This forces a cast to
 342   // the specified subclass and calls its accessor.  "getVectorNumElements" (for
 343   // example) is shorthand for cast<VectorType>(Ty)->getNumElements().  This is
 344   // only intended to cover the core methods that are frequently used, helper
 345   // methods should not be added here.
 346
 347   inline unsigned getIntegerBitWidth() const;
 348
 349   inline Type *getFunctionParamType(unsigned i) const;
 350   inline unsigned getFunctionNumParams() const;
 351   inline bool isFunctionVarArg() const;
 352
 353   inline StringRef getStructName() const;
 354   inline unsigned getStructNumElements() const;
 355   inline Type *getStructElementType(unsigned N) const;
 356
 357   inline Type *getSequentialElementType() const {
 358     assert(isSequentialType(getTypeID()) && "Not a sequential type!");
 359     return ContainedTys[0];
 360   }
 361
 362   inline uint64_t getArrayNumElements() const;
 363
 364   Type *getArrayElementType() const {
 365     assert(getTypeID() == ArrayTyID);
 366     return ContainedTys[0];
 367   }
 368
 369   inline bool getVectorIsScalable() const;
 370   inline unsigned getVectorNumElements() const;
 371   Type *getVectorElementType() const {
 372     assert(getTypeID() == VectorTyID);
 373     return ContainedTys[0];
 374   }
 375
 376   Type *getPointerElementType() const {
 377     assert(getTypeID() == PointerTyID);
 378     return ContainedTys[0];
 379   }
 380
 381   /// Get the address space of this pointer or pointer vector type.
 382   inline unsigned getPointerAddressSpace() const;
 383
 384   //===--------------------------------------------------------------------===//
 385   // Static members exported by the Type class itself.  Useful for getting
 386   // instances of Type.
 387   //
 388
 389   /// Return a type based on an identifier.
 390   static Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber);
 391
 392   //===--------------------------------------------------------------------===//
 393   // These are the builtin types that are always available.
 394   //
 395   static Type *getVoidTy(LLVMContext &C);
 396   static Type *getLabelTy(LLVMContext &C);
 397   static Type *getHalfTy(LLVMContext &C);
 398   static Type *getFloatTy(LLVMContext &C);
 399   static Type *getDoubleTy(LLVMContext &C);
 400   static Type *getMetadataTy(LLVMContext &C);
 401   static Type *getX86_FP80Ty(LLVMContext &C);
 402   static Type *getFP128Ty(LLVMContext &C);
 403   static Type *getPPC_FP128Ty(LLVMContext &C);
 404   static Type *getX86_MMXTy(LLVMContext &C);
 405   static Type *getTokenTy(LLVMContext &C);
 406   static IntegerType *getIntNTy(LLVMContext &C, unsigned N);
 407   static IntegerType *getInt1Ty(LLVMContext &C);
 408   static IntegerType *getInt8Ty(LLVMContext &C);
 409   static IntegerType *getInt16Ty(LLVMContext &C);
 410   static IntegerType *getInt32Ty(LLVMContext &C);
 411   static IntegerType *getInt64Ty(LLVMContext &C);
 412   static IntegerType *getInt128Ty(LLVMContext &C);
 413   template <typename ScalarTy> static Type *getScalarTy(LLVMContext &C) {
 414     int noOfBits = sizeof(ScalarTy) * CHAR_BIT;
 415     if (std::is_integral<ScalarTy>::value) {
 416       return (Type*) Type::getIntNTy(C, noOfBits);
 417     } else if (std::is_floating_point<ScalarTy>::value) {
 418       switch (noOfBits) {
 419       case 32:
 420         return Type::getFloatTy(C);
 421       case 64:
 422         return Type::getDoubleTy(C);
 423       }
 424     }
 425     llvm_unreachable("Unsupported type in Type::getScalarTy");
 426   }
 427
 428   //===--------------------------------------------------------------------===//
 429   // Convenience methods for getting pointer types with one of the above builtin
 430   // types as pointee.
 431   //
 432   static PointerType *getHalfPtrTy(LLVMContext &C, unsigned AS = 0);
 433   static PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0);
 434   static PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0);
 435   static PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0);
 436   static PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0);
 437   static PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0);
 438   static PointerType *getX86_MMXPtrTy(LLVMContext &C, unsigned AS = 0);
 439   static PointerType *getIntNPtrTy(LLVMContext &C, unsigned N, unsigned AS = 0);
 440   static PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0);
 441   static PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
 442   static PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0);
 443   static PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0);
 444   static PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0);
 445
 446   /// Return a pointer to the current type. This is equivalent to
 447   /// PointerType::get(Foo, AddrSpace).
 448   PointerType *getPointerTo(unsigned AddrSpace = 0) const;
 449
 450 private:
 451   /// Derived types like structures and arrays are sized iff all of the members
 452   /// of the type are sized as well. Since asking for their size is relatively
 453   /// uncommon, move this operation out-of-line.
 454   bool isSizedDerivedType(SmallPtrSetImpl<Type*> *Visited = nullptr) const;
 455 };
 456
 457 // Printing of types.
 458 inline raw_ostream &operator<<(raw_ostream &OS, const Type &T) {
 459   T.print(OS);
 460   return OS;
 461 }
 462
 463 // allow isa<PointerType>(x) to work without DerivedTypes.h included.
 464 template <> struct isa_impl<PointerType, Type> {
 465   static inline bool doit(const Type &Ty) {
 466     return Ty.getTypeID() == Type::PointerTyID;
 467   }
 468 };
 469
 470 // Create wrappers for C Binding types (see CBindingWrapping.h).
 471 DEFINE_ISA_CONVERSION_FUNCTIONS(Type, LLVMTypeRef)
 472
 473 /* Specialized opaque type conversions.
 474  */
 475 inline Type **unwrap(LLVMTypeRef* Tys) {
 476   return reinterpret_cast<Type**>(Tys);
 477 }
 478
 479 inline LLVMTypeRef *wrap(Type **Tys) {
 480   return reinterpret_cast<LLVMTypeRef*>(const_cast<Type**>(Tys));
 481 }
 482
 483 } // end namespace llvm
 484
 485 #endif // LLVM_IR_TYPE_H