Home | History | Annotate | Download | only in IR 
      1 //===-- llvm/Type.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 declaration of the Type class.  For more "Type"
     11 // stuff, look in DerivedTypes.h.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #ifndef LLVM_IR_TYPE_H
     16 #define LLVM_IR_TYPE_H
     17 
     18 #include "llvm/ADT/APFloat.h"
     19 #include "llvm/Support/Casting.h"
     20 #include "llvm/Support/CBindingWrapping.h"
     21 #include "llvm/Support/DataTypes.h"
     22 #include "llvm/Support/ErrorHandling.h"
     23 #include "llvm-c/Core.h"
     24 
     25 namespace llvm {
     26 
     27 class PointerType;
     28 class IntegerType;
     29 class raw_ostream;
     30 class Module;
     31 class LLVMContext;
     32 class LLVMContextImpl;
     33 class StringRef;
     34 template<class GraphType> struct GraphTraits;
     35 
     36 /// The instances of the Type class are immutable: once they are created,
     37 /// they are never changed.  Also note that only one instance of a particular
     38 /// type is ever created.  Thus seeing if two types are equal is a matter of
     39 /// doing a trivial pointer comparison. To enforce that no two equal instances
     40 /// are created, Type instances can only be created via static factory methods
     41 /// in class Type and in derived classes.  Once allocated, Types are never
     42 /// free'd.
     43 ///
     44 class Type {
     45 public:
     46   //===--------------------------------------------------------------------===//
     47   /// Definitions of all of the base types for the Type system.  Based on this
     48   /// value, you can cast to a class defined in DerivedTypes.h.
     49   /// Note: If you add an element to this, you need to add an element to the
     50   /// Type::getPrimitiveType function, or else things will break!
     51   /// Also update LLVMTypeKind and LLVMGetTypeKind () in the C binding.
     52   ///
     53   enum TypeID {
     54     // PrimitiveTypes - make sure LastPrimitiveTyID stays up to date.
     55     VoidTyID = 0,    ///<  0: type with no size
     56     HalfTyID,        ///<  1: 16-bit floating point type
     57     FloatTyID,       ///<  2: 32-bit floating point type
     58     DoubleTyID,      ///<  3: 64-bit floating point type
     59     X86_FP80TyID,    ///<  4: 80-bit floating point type (X87)
     60     FP128TyID,       ///<  5: 128-bit floating point type (112-bit mantissa)
     61     PPC_FP128TyID,   ///<  6: 128-bit floating point type (two 64-bits, PowerPC)
     62     LabelTyID,       ///<  7: Labels
     63     MetadataTyID,    ///<  8: Metadata
     64     X86_MMXTyID,     ///<  9: MMX vectors (64 bits, X86 specific)
     65 
     66     // Derived types... see DerivedTypes.h file.
     67     // Make sure FirstDerivedTyID stays up to date!
     68     IntegerTyID,     ///< 10: Arbitrary bit width integers
     69     FunctionTyID,    ///< 11: Functions
     70     StructTyID,      ///< 12: Structures
     71     ArrayTyID,       ///< 13: Arrays
     72     PointerTyID,     ///< 14: Pointers
     73     VectorTyID,      ///< 15: SIMD 'packed' format, or other vector type
     74 
     75     NumTypeIDs,                         // Must remain as last defined ID
     76     LastPrimitiveTyID = X86_MMXTyID,
     77     FirstDerivedTyID = IntegerTyID
     78   };
     79 
     80 private:
     81   /// Context - This refers to the LLVMContext in which this type was uniqued.
     82   LLVMContext &Context;
     83 
     84   // Due to Ubuntu GCC bug 910363:
     85   // https://bugs.launchpad.net/ubuntu/+source/gcc-4.5/+bug/910363
     86   // Bitpack ID and SubclassData manually.
     87   // Note: TypeID : low 8 bit; SubclassData : high 24 bit.
     88   uint32_t IDAndSubclassData;
     89 
     90 protected:
     91   friend class LLVMContextImpl;
     92   explicit Type(LLVMContext &C, TypeID tid)
     93     : Context(C), IDAndSubclassData(0),
     94       NumContainedTys(0), ContainedTys(0) {
     95     setTypeID(tid);
     96   }
     97   ~Type() {}
     98 
     99   void setTypeID(TypeID ID) {
    100     IDAndSubclassData = (ID & 0xFF) | (IDAndSubclassData & 0xFFFFFF00);
    101     assert(getTypeID() == ID && "TypeID data too large for field");
    102   }
    103 
    104   unsigned getSubclassData() const { return IDAndSubclassData >> 8; }
    105 
    106   void setSubclassData(unsigned val) {
    107     IDAndSubclassData = (IDAndSubclassData & 0xFF) | (val << 8);
    108     // Ensure we don't have any accidental truncation.
    109     assert(getSubclassData() == val && "Subclass data too large for field");
    110   }
    111 
    112   /// NumContainedTys - Keeps track of how many Type*'s there are in the
    113   /// ContainedTys list.
    114   unsigned NumContainedTys;
    115 
    116   /// ContainedTys - A pointer to the array of Types contained by this Type.
    117   /// For example, this includes the arguments of a function type, the elements
    118   /// of a structure, the pointee of a pointer, the element type of an array,
    119   /// etc.  This pointer may be 0 for types that don't contain other types
    120   /// (Integer, Double, Float).
    121   Type * const *ContainedTys;
    122 
    123 public:
    124   void print(raw_ostream &O) const;
    125   void dump() const;
    126 
    127   /// getContext - Return the LLVMContext in which this type was uniqued.
    128   LLVMContext &getContext() const { return Context; }
    129 
    130   //===--------------------------------------------------------------------===//
    131   // Accessors for working with types.
    132   //
    133 
    134   /// getTypeID - Return the type id for the type.  This will return one
    135   /// of the TypeID enum elements defined above.
    136   ///
    137   TypeID getTypeID() const { return (TypeID)(IDAndSubclassData & 0xFF); }
    138 
    139   /// isVoidTy - Return true if this is 'void'.
    140   bool isVoidTy() const { return getTypeID() == VoidTyID; }
    141 
    142   /// isHalfTy - Return true if this is 'half', a 16-bit IEEE fp type.
    143   bool isHalfTy() const { return getTypeID() == HalfTyID; }
    144 
    145   /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type.
    146   bool isFloatTy() const { return getTypeID() == FloatTyID; }
    147 
    148   /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type.
    149   bool isDoubleTy() const { return getTypeID() == DoubleTyID; }
    150 
    151   /// isX86_FP80Ty - Return true if this is x86 long double.
    152   bool isX86_FP80Ty() const { return getTypeID() == X86_FP80TyID; }
    153 
    154   /// isFP128Ty - Return true if this is 'fp128'.
    155   bool isFP128Ty() const { return getTypeID() == FP128TyID; }
    156 
    157   /// isPPC_FP128Ty - Return true if this is powerpc long double.
    158   bool isPPC_FP128Ty() const { return getTypeID() == PPC_FP128TyID; }
    159 
    160   /// isFloatingPointTy - Return true if this is one of the six floating point
    161   /// types
    162   bool isFloatingPointTy() const {
    163     return getTypeID() == HalfTyID || getTypeID() == FloatTyID ||
    164            getTypeID() == DoubleTyID ||
    165            getTypeID() == X86_FP80TyID || getTypeID() == FP128TyID ||
    166            getTypeID() == PPC_FP128TyID;
    167   }
    168 
    169   const fltSemantics &getFltSemantics() const {
    170     switch (getTypeID()) {
    171     case HalfTyID: return APFloat::IEEEhalf;
    172     case FloatTyID: return APFloat::IEEEsingle;
    173     case DoubleTyID: return APFloat::IEEEdouble;
    174     case X86_FP80TyID: return APFloat::x87DoubleExtended;
    175     case FP128TyID: return APFloat::IEEEquad;
    176     case PPC_FP128TyID: return APFloat::PPCDoubleDouble;
    177     default: llvm_unreachable("Invalid floating type");
    178     }
    179   }
    180 
    181   /// isX86_MMXTy - Return true if this is X86 MMX.
    182   bool isX86_MMXTy() const { return getTypeID() == X86_MMXTyID; }
    183 
    184   /// isFPOrFPVectorTy - Return true if this is a FP type or a vector of FP.
    185   ///
    186   bool isFPOrFPVectorTy() const { return getScalarType()->isFloatingPointTy(); }
    187 
    188   /// isLabelTy - Return true if this is 'label'.
    189   bool isLabelTy() const { return getTypeID() == LabelTyID; }
    190 
    191   /// isMetadataTy - Return true if this is 'metadata'.
    192   bool isMetadataTy() const { return getTypeID() == MetadataTyID; }
    193 
    194   /// isIntegerTy - True if this is an instance of IntegerType.
    195   ///
    196   bool isIntegerTy() const { return getTypeID() == IntegerTyID; }
    197 
    198   /// isIntegerTy - Return true if this is an IntegerType of the given width.
    199   bool isIntegerTy(unsigned Bitwidth) const;
    200 
    201   /// isIntOrIntVectorTy - Return true if this is an integer type or a vector of
    202   /// integer types.
    203   ///
    204   bool isIntOrIntVectorTy() const { return getScalarType()->isIntegerTy(); }
    205 
    206   /// isFunctionTy - True if this is an instance of FunctionType.
    207   ///
    208   bool isFunctionTy() const { return getTypeID() == FunctionTyID; }
    209 
    210   /// isStructTy - True if this is an instance of StructType.
    211   ///
    212   bool isStructTy() const { return getTypeID() == StructTyID; }
    213 
    214   /// isArrayTy - True if this is an instance of ArrayType.
    215   ///
    216   bool isArrayTy() const { return getTypeID() == ArrayTyID; }
    217 
    218   /// isPointerTy - True if this is an instance of PointerType.
    219   ///
    220   bool isPointerTy() const { return getTypeID() == PointerTyID; }
    221 
    222   /// isPtrOrPtrVectorTy - Return true if this is a pointer type or a vector of
    223   /// pointer types.
    224   ///
    225   bool isPtrOrPtrVectorTy() const { return getScalarType()->isPointerTy(); }
    226 
    227   /// isVectorTy - True if this is an instance of VectorType.
    228   ///
    229   bool isVectorTy() const { return getTypeID() == VectorTyID; }
    230 
    231   /// canLosslesslyBitCastTo - Return true if this type could be converted
    232   /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts
    233   /// are valid for types of the same size only where no re-interpretation of
    234   /// the bits is done.
    235   /// @brief Determine if this type could be losslessly bitcast to Ty
    236   bool canLosslesslyBitCastTo(Type *Ty) const;
    237 
    238   /// isEmptyTy - Return true if this type is empty, that is, it has no
    239   /// elements or all its elements are empty.
    240   bool isEmptyTy() const;
    241 
    242   /// Here are some useful little methods to query what type derived types are
    243   /// Note that all other types can just compare to see if this == Type::xxxTy;
    244   ///
    245   bool isPrimitiveType() const { return getTypeID() <= LastPrimitiveTyID; }
    246   bool isDerivedType()   const { return getTypeID() >= FirstDerivedTyID; }
    247 
    248   /// isFirstClassType - Return true if the type is "first class", meaning it
    249   /// is a valid type for a Value.
    250   ///
    251   bool isFirstClassType() const {
    252     return getTypeID() != FunctionTyID && getTypeID() != VoidTyID;
    253   }
    254 
    255   /// isSingleValueType - Return true if the type is a valid type for a
    256   /// register in codegen.  This includes all first-class types except struct
    257   /// and array types.
    258   ///
    259   bool isSingleValueType() const {
    260     return (getTypeID() != VoidTyID && isPrimitiveType()) ||
    261             getTypeID() == IntegerTyID || getTypeID() == PointerTyID ||
    262             getTypeID() == VectorTyID;
    263   }
    264 
    265   /// isAggregateType - Return true if the type is an aggregate type. This
    266   /// means it is valid as the first operand of an insertvalue or
    267   /// extractvalue instruction. This includes struct and array types, but
    268   /// does not include vector types.
    269   ///
    270   bool isAggregateType() const {
    271     return getTypeID() == StructTyID || getTypeID() == ArrayTyID;
    272   }
    273 
    274   /// isSized - Return true if it makes sense to take the size of this type.  To
    275   /// get the actual size for a particular target, it is reasonable to use the
    276   /// DataLayout subsystem to do this.
    277   ///
    278   bool isSized() const {
    279     // If it's a primitive, it is always sized.
    280     if (getTypeID() == IntegerTyID || isFloatingPointTy() ||
    281         getTypeID() == PointerTyID ||
    282         getTypeID() == X86_MMXTyID)
    283       return true;
    284     // If it is not something that can have a size (e.g. a function or label),
    285     // it doesn't have a size.
    286     if (getTypeID() != StructTyID && getTypeID() != ArrayTyID &&
    287         getTypeID() != VectorTyID)
    288       return false;
    289     // Otherwise we have to try harder to decide.
    290     return isSizedDerivedType();
    291   }
    292 
    293   /// getPrimitiveSizeInBits - Return the basic size of this type if it is a
    294   /// primitive type.  These are fixed by LLVM and are not target dependent.
    295   /// This will return zero if the type does not have a size or is not a
    296   /// primitive type.
    297   ///
    298   /// Note that this may not reflect the size of memory allocated for an
    299   /// instance of the type or the number of bytes that are written when an
    300   /// instance of the type is stored to memory. The DataLayout class provides
    301   /// additional query functions to provide this information.
    302   ///
    303   unsigned getPrimitiveSizeInBits() const;
    304 
    305   /// getScalarSizeInBits - If this is a vector type, return the
    306   /// getPrimitiveSizeInBits value for the element type. Otherwise return the
    307   /// getPrimitiveSizeInBits value for this type.
    308   unsigned getScalarSizeInBits();
    309 
    310   /// getFPMantissaWidth - Return the width of the mantissa of this type.  This
    311   /// is only valid on floating point types.  If the FP type does not
    312   /// have a stable mantissa (e.g. ppc long double), this method returns -1.
    313   int getFPMantissaWidth() const;
    314 
    315   /// getScalarType - If this is a vector type, return the element type,
    316   /// otherwise return 'this'.
    317   const Type *getScalarType() const;
    318   Type *getScalarType();
    319 
    320   //===--------------------------------------------------------------------===//
    321   // Type Iteration support.
    322   //
    323   typedef Type * const *subtype_iterator;
    324   subtype_iterator subtype_begin() const { return ContainedTys; }
    325   subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];}
    326 
    327   /// getContainedType - This method is used to implement the type iterator
    328   /// (defined a the end of the file).  For derived types, this returns the
    329   /// types 'contained' in the derived type.
    330   ///
    331   Type *getContainedType(unsigned i) const {
    332     assert(i < NumContainedTys && "Index out of range!");
    333     return ContainedTys[i];
    334   }
    335 
    336   /// getNumContainedTypes - Return the number of types in the derived type.
    337   ///
    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   unsigned getIntegerBitWidth() const;
    348 
    349   Type *getFunctionParamType(unsigned i) const;
    350   unsigned getFunctionNumParams() const;
    351   bool isFunctionVarArg() const;
    352 
    353   StringRef getStructName() const;
    354   unsigned getStructNumElements() const;
    355   Type *getStructElementType(unsigned N) const;
    356 
    357   Type *getSequentialElementType() const;
    358 
    359   uint64_t getArrayNumElements() const;
    360   Type *getArrayElementType() const { return getSequentialElementType(); }
    361 
    362   unsigned getVectorNumElements() const;
    363   Type *getVectorElementType() const { return getSequentialElementType(); }
    364 
    365   Type *getPointerElementType() const { return getSequentialElementType(); }
    366 
    367   /// \brief Get the address space of this pointer or pointer vector type.
    368   unsigned getPointerAddressSpace() const;
    369 
    370   //===--------------------------------------------------------------------===//
    371   // Static members exported by the Type class itself.  Useful for getting
    372   // instances of Type.
    373   //
    374 
    375   /// getPrimitiveType - Return a type based on an identifier.
    376   static Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber);
    377 
    378   //===--------------------------------------------------------------------===//
    379   // These are the builtin types that are always available.
    380   //
    381   static Type *getVoidTy(LLVMContext &C);
    382   static Type *getLabelTy(LLVMContext &C);
    383   static Type *getHalfTy(LLVMContext &C);
    384   static Type *getFloatTy(LLVMContext &C);
    385   static Type *getDoubleTy(LLVMContext &C);
    386   static Type *getMetadataTy(LLVMContext &C);
    387   static Type *getX86_FP80Ty(LLVMContext &C);
    388   static Type *getFP128Ty(LLVMContext &C);
    389   static Type *getPPC_FP128Ty(LLVMContext &C);
    390   static Type *getX86_MMXTy(LLVMContext &C);
    391   static IntegerType *getIntNTy(LLVMContext &C, unsigned N);
    392   static IntegerType *getInt1Ty(LLVMContext &C);
    393   static IntegerType *getInt8Ty(LLVMContext &C);
    394   static IntegerType *getInt16Ty(LLVMContext &C);
    395   static IntegerType *getInt32Ty(LLVMContext &C);
    396   static IntegerType *getInt64Ty(LLVMContext &C);
    397 
    398   //===--------------------------------------------------------------------===//
    399   // Convenience methods for getting pointer types with one of the above builtin
    400   // types as pointee.
    401   //
    402   static PointerType *getHalfPtrTy(LLVMContext &C, unsigned AS = 0);
    403   static PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0);
    404   static PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0);
    405   static PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0);
    406   static PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0);
    407   static PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0);
    408   static PointerType *getX86_MMXPtrTy(LLVMContext &C, unsigned AS = 0);
    409   static PointerType *getIntNPtrTy(LLVMContext &C, unsigned N, unsigned AS = 0);
    410   static PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0);
    411   static PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
    412   static PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0);
    413   static PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0);
    414   static PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0);
    415 
    416   /// getPointerTo - Return a pointer to the current type.  This is equivalent
    417   /// to PointerType::get(Foo, AddrSpace).
    418   PointerType *getPointerTo(unsigned AddrSpace = 0);
    419 
    420 private:
    421   /// isSizedDerivedType - Derived types like structures and arrays are sized
    422   /// iff all of the members of the type are sized as well.  Since asking for
    423   /// their size is relatively uncommon, move this operation out of line.
    424   bool isSizedDerivedType() const;
    425 };
    426 
    427 // Printing of types.
    428 static inline raw_ostream &operator<<(raw_ostream &OS, Type &T) {
    429   T.print(OS);
    430   return OS;
    431 }
    432 
    433 // allow isa<PointerType>(x) to work without DerivedTypes.h included.
    434 template <> struct isa_impl<PointerType, Type> {
    435   static inline bool doit(const Type &Ty) {
    436     return Ty.getTypeID() == Type::PointerTyID;
    437   }
    438 };
    439 
    440 
    441 //===----------------------------------------------------------------------===//
    442 // Provide specializations of GraphTraits to be able to treat a type as a
    443 // graph of sub types.
    444 
    445 
    446 template <> struct GraphTraits<Type*> {
    447   typedef Type NodeType;
    448   typedef Type::subtype_iterator ChildIteratorType;
    449 
    450   static inline NodeType *getEntryNode(Type *T) { return T; }
    451   static inline ChildIteratorType child_begin(NodeType *N) {
    452     return N->subtype_begin();
    453   }
    454   static inline ChildIteratorType child_end(NodeType *N) {
    455     return N->subtype_end();
    456   }
    457 };
    458 
    459 template <> struct GraphTraits<const Type*> {
    460   typedef const Type NodeType;
    461   typedef Type::subtype_iterator ChildIteratorType;
    462 
    463   static inline NodeType *getEntryNode(NodeType *T) { return T; }
    464   static inline ChildIteratorType child_begin(NodeType *N) {
    465     return N->subtype_begin();
    466   }
    467   static inline ChildIteratorType child_end(NodeType *N) {
    468     return N->subtype_end();
    469   }
    470 };
    471 
    472 // Create wrappers for C Binding types (see CBindingWrapping.h).
    473 DEFINE_ISA_CONVERSION_FUNCTIONS(Type, LLVMTypeRef)
    474 
    475 /* Specialized opaque type conversions.
    476  */
    477 inline Type **unwrap(LLVMTypeRef* Tys) {
    478   return reinterpret_cast<Type**>(Tys);
    479 }
    480 
    481 inline LLVMTypeRef *wrap(Type **Tys) {
    482   return reinterpret_cast<LLVMTypeRef*>(const_cast<Type**>(Tys));
    483 }
    484 
    485 } // End llvm namespace
    486 
    487 #endif
    488