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 AttributeSet;
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   std::string getName(ID id, ArrayRef<Type*> Tys = None);
49 
50   /// Return the function type for an intrinsic.
51   FunctionType *getType(LLVMContext &Context, ID id,
52                         ArrayRef<Type*> Tys = None);
53 
54   /// Returns true if the intrinsic can be overloaded.
55   bool isOverloaded(ID id);
56 
57   /// Returns true if the intrinsic is a leaf, i.e. it does not make any calls
58   /// itself.  Most intrinsics are leafs, the exceptions being the patchpoint
59   /// and statepoint intrinsics. These call (or invoke) their "target" argument.
60   bool isLeaf(ID id);
61 
62   /// Return the attributes for an intrinsic.
63   AttributeSet getAttributes(LLVMContext &C, ID id);
64 
65   /// Create or insert an LLVM Function declaration for an intrinsic, and return
66   /// it.
67   ///
68   /// The Tys parameter is for intrinsics with overloaded types (e.g., those
69   /// using iAny, fAny, vAny, or iPTRAny).  For a declaration of an overloaded
70   /// intrinsic, Tys must provide exactly one type for each overloaded type in
71   /// the intrinsic.
72   Function *getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys = None);
73 
74   /// Looks up Name in NameTable via binary search. NameTable must be sorted
75   /// and all entries must start with "llvm.".  If NameTable contains an exact
76   /// match for Name or a prefix of Name followed by a dot, its index in
77   /// NameTable is returned. Otherwise, -1 is returned.
78   int lookupLLVMIntrinsicByName(ArrayRef<const char *> NameTable,
79                                 StringRef Name);
80 
81   /// Map a GCC builtin name to an intrinsic ID.
82   ID getIntrinsicForGCCBuiltin(const char *Prefix, const char *BuiltinName);
83 
84   /// Map a MS builtin name to an intrinsic ID.
85   ID getIntrinsicForMSBuiltin(const char *Prefix, const char *BuiltinName);
86 
87   /// This is a type descriptor which explains the type requirements of an
88   /// intrinsic. This is returned by getIntrinsicInfoTableEntries.
89   struct IITDescriptor {
90     enum IITDescriptorKind {
91       Void, VarArg, MMX, Token, Metadata, Half, Float, Double,
92       Integer, Vector, Pointer, Struct,
93       Argument, ExtendArgument, TruncArgument, HalfVecArgument,
94       SameVecWidthArgument, PtrToArgument, VecOfPtrsToElt
95     } Kind;
96 
97     union {
98       unsigned Integer_Width;
99       unsigned Float_Width;
100       unsigned Vector_Width;
101       unsigned Pointer_AddressSpace;
102       unsigned Struct_NumElements;
103       unsigned Argument_Info;
104     };
105 
106     enum ArgKind {
107       AK_Any,
108       AK_AnyInteger,
109       AK_AnyFloat,
110       AK_AnyVector,
111       AK_AnyPointer
112     };
getArgumentNumberIITDescriptor113     unsigned getArgumentNumber() const {
114       assert(Kind == Argument || Kind == ExtendArgument ||
115              Kind == TruncArgument || Kind == HalfVecArgument ||
116              Kind == SameVecWidthArgument || Kind == PtrToArgument ||
117              Kind == VecOfPtrsToElt);
118       return Argument_Info >> 3;
119     }
getArgumentKindIITDescriptor120     ArgKind getArgumentKind() const {
121       assert(Kind == Argument || Kind == ExtendArgument ||
122              Kind == TruncArgument || Kind == HalfVecArgument ||
123              Kind == SameVecWidthArgument || Kind == PtrToArgument ||
124              Kind == VecOfPtrsToElt);
125       return (ArgKind)(Argument_Info & 7);
126     }
127 
getIITDescriptor128     static IITDescriptor get(IITDescriptorKind K, unsigned Field) {
129       IITDescriptor Result = { K, { Field } };
130       return Result;
131     }
132   };
133 
134   /// Return the IIT table descriptor for the specified intrinsic into an array
135   /// of IITDescriptors.
136   void getIntrinsicInfoTableEntries(ID id, SmallVectorImpl<IITDescriptor> &T);
137 
138   /// Match the specified type (which comes from an intrinsic argument or return
139   /// value) with the type constraints specified by the .td file. If the given
140   /// type is an overloaded type it is pushed to the ArgTys vector.
141   ///
142   /// Returns false if the given type matches with the constraints, true
143   /// otherwise.
144   bool matchIntrinsicType(Type *Ty, ArrayRef<IITDescriptor> &Infos,
145                           SmallVectorImpl<Type*> &ArgTys);
146 
147   /// Verify if the intrinsic has variable arguments. This method is intended to
148   /// be called after all the fixed arguments have been matched first.
149   ///
150   /// This method returns true on error.
151   bool matchIntrinsicVarArg(bool isVarArg, ArrayRef<IITDescriptor> &Infos);
152 
153   // Checks if the intrinsic name matches with its signature and if not
154   // returns the declaration with the same signature and remangled name.
155   llvm::Optional<Function*> remangleIntrinsicFunction(Function *F);
156 
157 } // End Intrinsic namespace
158 
159 } // End llvm namespace
160 
161 #endif
162