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      1 //===-- llvm/Instrinsics.h - LLVM Intrinsic Function Handling ---*- 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 defines a set of enums which allow processing of intrinsic
     11 // functions.  Values of these enum types are returned by
     12 // Function::getIntrinsicID.
     13 //
     14 //===----------------------------------------------------------------------===//
     15 
     16 #ifndef LLVM_IR_INTRINSICS_H
     17 #define LLVM_IR_INTRINSICS_H
     18 
     19 #include "llvm/ADT/ArrayRef.h"
     20 #include "llvm/ADT/None.h"
     21 #include "llvm/ADT/Optional.h"
     22 #include <string>
     23 
     24 namespace llvm {
     25 
     26 class Type;
     27 class FunctionType;
     28 class Function;
     29 class LLVMContext;
     30 class Module;
     31 class AttributeList;
     32 
     33 /// This namespace contains an enum with a value for every intrinsic/builtin
     34 /// function known by LLVM. The enum values are returned by
     35 /// Function::getIntrinsicID().
     36 namespace Intrinsic {
     37   enum ID : unsigned {
     38     not_intrinsic = 0,   // Must be zero
     39 
     40     // Get the intrinsic enums generated from Intrinsics.td
     41 #define GET_INTRINSIC_ENUM_VALUES
     42 #include "llvm/IR/Intrinsics.gen"
     43 #undef GET_INTRINSIC_ENUM_VALUES
     44     , num_intrinsics
     45   };
     46 
     47   /// Return the LLVM name for an intrinsic, such as "llvm.ppc.altivec.lvx".
     48   /// Note, this version is for intrinsics with no overloads.  Use the other
     49   /// version of getName if overloads are required.
     50   StringRef getName(ID id);
     51 
     52   /// Return the LLVM name for an intrinsic, such as "llvm.ppc.altivec.lvx".
     53   /// Note, this version of getName supports overloads, but is less efficient
     54   /// than the StringRef version of this function.  If no overloads are
     55   /// requried, it is safe to use this version, but better to use the StringRef
     56   /// version.
     57   std::string getName(ID id, ArrayRef<Type*> Tys);
     58 
     59   /// Return the function type for an intrinsic.
     60   FunctionType *getType(LLVMContext &Context, ID id,
     61                         ArrayRef<Type*> Tys = None);
     62 
     63   /// Returns true if the intrinsic can be overloaded.
     64   bool isOverloaded(ID id);
     65 
     66   /// Returns true if the intrinsic is a leaf, i.e. it does not make any calls
     67   /// itself.  Most intrinsics are leafs, the exceptions being the patchpoint
     68   /// and statepoint intrinsics. These call (or invoke) their "target" argument.
     69   bool isLeaf(ID id);
     70 
     71   /// Return the attributes for an intrinsic.
     72   AttributeList getAttributes(LLVMContext &C, ID id);
     73 
     74   /// Create or insert an LLVM Function declaration for an intrinsic, and return
     75   /// it.
     76   ///
     77   /// The Tys parameter is for intrinsics with overloaded types (e.g., those
     78   /// using iAny, fAny, vAny, or iPTRAny).  For a declaration of an overloaded
     79   /// intrinsic, Tys must provide exactly one type for each overloaded type in
     80   /// the intrinsic.
     81   Function *getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys = None);
     82 
     83   /// Looks up Name in NameTable via binary search. NameTable must be sorted
     84   /// and all entries must start with "llvm.".  If NameTable contains an exact
     85   /// match for Name or a prefix of Name followed by a dot, its index in
     86   /// NameTable is returned. Otherwise, -1 is returned.
     87   int lookupLLVMIntrinsicByName(ArrayRef<const char *> NameTable,
     88                                 StringRef Name);
     89 
     90   /// Map a GCC builtin name to an intrinsic ID.
     91   ID getIntrinsicForGCCBuiltin(const char *Prefix, StringRef BuiltinName);
     92 
     93   /// Map a MS builtin name to an intrinsic ID.
     94   ID getIntrinsicForMSBuiltin(const char *Prefix, StringRef BuiltinName);
     95 
     96   /// This is a type descriptor which explains the type requirements of an
     97   /// intrinsic. This is returned by getIntrinsicInfoTableEntries.
     98   struct IITDescriptor {
     99     enum IITDescriptorKind {
    100       Void, VarArg, MMX, Token, Metadata, Half, Float, Double,
    101       Integer, Vector, Pointer, Struct,
    102       Argument, ExtendArgument, TruncArgument, HalfVecArgument,
    103       SameVecWidthArgument, PtrToArgument, PtrToElt, VecOfAnyPtrsToElt
    104     } Kind;
    105 
    106     union {
    107       unsigned Integer_Width;
    108       unsigned Float_Width;
    109       unsigned Vector_Width;
    110       unsigned Pointer_AddressSpace;
    111       unsigned Struct_NumElements;
    112       unsigned Argument_Info;
    113     };
    114 
    115     enum ArgKind {
    116       AK_Any,
    117       AK_AnyInteger,
    118       AK_AnyFloat,
    119       AK_AnyVector,
    120       AK_AnyPointer
    121     };
    122 
    123     unsigned getArgumentNumber() const {
    124       assert(Kind == Argument || Kind == ExtendArgument ||
    125              Kind == TruncArgument || Kind == HalfVecArgument ||
    126              Kind == SameVecWidthArgument || Kind == PtrToArgument ||
    127              Kind == PtrToElt);
    128       return Argument_Info >> 3;
    129     }
    130     ArgKind getArgumentKind() const {
    131       assert(Kind == Argument || Kind == ExtendArgument ||
    132              Kind == TruncArgument || Kind == HalfVecArgument ||
    133              Kind == SameVecWidthArgument || Kind == PtrToArgument);
    134       return (ArgKind)(Argument_Info & 7);
    135     }
    136 
    137     // VecOfAnyPtrsToElt uses both an overloaded argument (for address space)
    138     // and a reference argument (for matching vector width and element types)
    139     unsigned getOverloadArgNumber() const {
    140       assert(Kind == VecOfAnyPtrsToElt);
    141       return Argument_Info >> 16;
    142     }
    143     unsigned getRefArgNumber() const {
    144       assert(Kind == VecOfAnyPtrsToElt);
    145       return Argument_Info & 0xFFFF;
    146     }
    147 
    148     static IITDescriptor get(IITDescriptorKind K, unsigned Field) {
    149       IITDescriptor Result = { K, { Field } };
    150       return Result;
    151     }
    152 
    153     static IITDescriptor get(IITDescriptorKind K, unsigned short Hi,
    154                              unsigned short Lo) {
    155       unsigned Field = Hi << 16 | Lo;
    156       IITDescriptor Result = {K, {Field}};
    157       return Result;
    158     }
    159   };
    160 
    161   /// Return the IIT table descriptor for the specified intrinsic into an array
    162   /// of IITDescriptors.
    163   void getIntrinsicInfoTableEntries(ID id, SmallVectorImpl<IITDescriptor> &T);
    164 
    165   /// Match the specified type (which comes from an intrinsic argument or return
    166   /// value) with the type constraints specified by the .td file. If the given
    167   /// type is an overloaded type it is pushed to the ArgTys vector.
    168   ///
    169   /// Returns false if the given type matches with the constraints, true
    170   /// otherwise.
    171   bool matchIntrinsicType(Type *Ty, ArrayRef<IITDescriptor> &Infos,
    172                           SmallVectorImpl<Type*> &ArgTys);
    173 
    174   /// Verify if the intrinsic has variable arguments. This method is intended to
    175   /// be called after all the fixed arguments have been matched first.
    176   ///
    177   /// This method returns true on error.
    178   bool matchIntrinsicVarArg(bool isVarArg, ArrayRef<IITDescriptor> &Infos);
    179 
    180   // Checks if the intrinsic name matches with its signature and if not
    181   // returns the declaration with the same signature and remangled name.
    182   llvm::Optional<Function*> remangleIntrinsicFunction(Function *F);
    183 
    184 } // End Intrinsic namespace
    185 
    186 } // End llvm namespace
    187 
    188 #endif
    189