1 //===- Intrinsics.h - LLVM Intrinsic Function Handling ----------*- 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 defines a set of enums which allow processing of intrinsic
10 // functions.  Values of these enum types are returned by
11 // Function::getIntrinsicID.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_IR_INTRINSICS_H
16 #define LLVM_IR_INTRINSICS_H
17 
18 #include "llvm/ADT/ArrayRef.h"
19 #include "llvm/Support/TypeSize.h"
20 #include <optional>
21 #include <string>
22 
23 namespace llvm {
24 
25 class Type;
26 class FunctionType;
27 class Function;
28 class LLVMContext;
29 class Module;
30 class AttributeList;
31 
32 /// This namespace contains an enum with a value for every intrinsic/builtin
33 /// function known by LLVM. The enum values are returned by
34 /// Function::getIntrinsicID().
35 namespace Intrinsic {
36   // Abstraction for the arguments of the noalias intrinsics
37   static const int NoAliasScopeDeclScopeArg = 0;
38 
39   // Intrinsic ID type. This is an opaque typedef to facilitate splitting up
40   // the enum into target-specific enums.
41   typedef unsigned ID;
42 
43   enum IndependentIntrinsics : unsigned {
44     not_intrinsic = 0, // Must be zero
45 
46   // Get the intrinsic enums generated from Intrinsics.td
47 #define GET_INTRINSIC_ENUM_VALUES
48 #include "llvm/IR/IntrinsicEnums.inc"
49 #undef GET_INTRINSIC_ENUM_VALUES
50   };
51 
52   /// Return the LLVM name for an intrinsic, such as "llvm.ppc.altivec.lvx".
53   /// Note, this version is for intrinsics with no overloads.  Use the other
54   /// version of getName if overloads are required.
55   StringRef getName(ID id);
56 
57   /// Return the LLVM name for an intrinsic, without encoded types for
58   /// overloading, such as "llvm.ssa.copy".
59   StringRef getBaseName(ID id);
60 
61   /// Return the LLVM name for an intrinsic, such as "llvm.ppc.altivec.lvx" or
62   /// "llvm.ssa.copy.p0s_s.1". Note, this version of getName supports overloads.
63   /// This is less efficient than the StringRef version of this function.  If no
64   /// overloads are required, it is safe to use this version, but better to use
65   /// the StringRef version. If one of the types is based on an unnamed type, a
66   /// function type will be computed. Providing FT will avoid this computation.
67   std::string getName(ID Id, ArrayRef<Type *> Tys, Module *M,
68                       FunctionType *FT = nullptr);
69 
70   /// Return the LLVM name for an intrinsic. This is a special version only to
71   /// be used by LLVMIntrinsicCopyOverloadedName. It only supports overloads
72   /// based on named types.
73   std::string getNameNoUnnamedTypes(ID Id, ArrayRef<Type *> Tys);
74 
75   /// Return the function type for an intrinsic.
76   FunctionType *getType(LLVMContext &Context, ID id,
77                         ArrayRef<Type *> Tys = std::nullopt);
78 
79   /// Returns true if the intrinsic can be overloaded.
80   bool isOverloaded(ID id);
81 
82   /// Return the attributes for an intrinsic.
83   AttributeList getAttributes(LLVMContext &C, ID id);
84 
85   /// Create or insert an LLVM Function declaration for an intrinsic, and return
86   /// it.
87   ///
88   /// The Tys parameter is for intrinsics with overloaded types (e.g., those
89   /// using iAny, fAny, vAny, or iPTRAny).  For a declaration of an overloaded
90   /// intrinsic, Tys must provide exactly one type for each overloaded type in
91   /// the intrinsic.
92   Function *getDeclaration(Module *M, ID id,
93                            ArrayRef<Type *> Tys = std::nullopt);
94 
95   /// Looks up Name in NameTable via binary search. NameTable must be sorted
96   /// and all entries must start with "llvm.".  If NameTable contains an exact
97   /// match for Name or a prefix of Name followed by a dot, its index in
98   /// NameTable is returned. Otherwise, -1 is returned.
99   int lookupLLVMIntrinsicByName(ArrayRef<const char *> NameTable,
100                                 StringRef Name);
101 
102   /// Map a Clang builtin name to an intrinsic ID.
103   ID getIntrinsicForClangBuiltin(const char *Prefix, StringRef BuiltinName);
104 
105   /// Map a MS builtin name to an intrinsic ID.
106   ID getIntrinsicForMSBuiltin(const char *Prefix, StringRef BuiltinName);
107 
108   /// This is a type descriptor which explains the type requirements of an
109   /// intrinsic. This is returned by getIntrinsicInfoTableEntries.
110   struct IITDescriptor {
111     enum IITDescriptorKind {
112       Void,
113       VarArg,
114       MMX,
115       Token,
116       Metadata,
117       Half,
118       BFloat,
119       Float,
120       Double,
121       Quad,
122       Integer,
123       Vector,
124       Pointer,
125       Struct,
126       Argument,
127       ExtendArgument,
128       TruncArgument,
129       HalfVecArgument,
130       SameVecWidthArgument,
131       VecOfAnyPtrsToElt,
132       VecElementArgument,
133       Subdivide2Argument,
134       Subdivide4Argument,
135       VecOfBitcastsToInt,
136       AMX,
137       PPCQuad,
138       AArch64Svcount,
139     } Kind;
140 
141     union {
142       unsigned Integer_Width;
143       unsigned Float_Width;
144       unsigned Pointer_AddressSpace;
145       unsigned Struct_NumElements;
146       unsigned Argument_Info;
147       ElementCount Vector_Width;
148     };
149 
150     // AK_% : Defined in Intrinsics.td
151     enum ArgKind {
152 #define GET_INTRINSIC_ARGKIND
153 #include "llvm/IR/IntrinsicEnums.inc"
154 #undef GET_INTRINSIC_ARGKIND
155     };
156 
getArgumentNumberIITDescriptor157     unsigned getArgumentNumber() const {
158       assert(Kind == Argument || Kind == ExtendArgument ||
159              Kind == TruncArgument || Kind == HalfVecArgument ||
160              Kind == SameVecWidthArgument || Kind == VecElementArgument ||
161              Kind == Subdivide2Argument || Kind == Subdivide4Argument ||
162              Kind == VecOfBitcastsToInt);
163       return Argument_Info >> 3;
164     }
getArgumentKindIITDescriptor165     ArgKind getArgumentKind() const {
166       assert(Kind == Argument || Kind == ExtendArgument ||
167              Kind == TruncArgument || Kind == HalfVecArgument ||
168              Kind == SameVecWidthArgument ||
169              Kind == VecElementArgument || Kind == Subdivide2Argument ||
170              Kind == Subdivide4Argument || Kind == VecOfBitcastsToInt);
171       return (ArgKind)(Argument_Info & 7);
172     }
173 
174     // VecOfAnyPtrsToElt uses both an overloaded argument (for address space)
175     // and a reference argument (for matching vector width and element types)
getOverloadArgNumberIITDescriptor176     unsigned getOverloadArgNumber() const {
177       assert(Kind == VecOfAnyPtrsToElt);
178       return Argument_Info >> 16;
179     }
getRefArgNumberIITDescriptor180     unsigned getRefArgNumber() const {
181       assert(Kind == VecOfAnyPtrsToElt);
182       return Argument_Info & 0xFFFF;
183     }
184 
getIITDescriptor185     static IITDescriptor get(IITDescriptorKind K, unsigned Field) {
186       IITDescriptor Result = { K, { Field } };
187       return Result;
188     }
189 
getIITDescriptor190     static IITDescriptor get(IITDescriptorKind K, unsigned short Hi,
191                              unsigned short Lo) {
192       unsigned Field = Hi << 16 | Lo;
193       IITDescriptor Result = {K, {Field}};
194       return Result;
195     }
196 
getVectorIITDescriptor197     static IITDescriptor getVector(unsigned Width, bool IsScalable) {
198       IITDescriptor Result = {Vector, {0}};
199       Result.Vector_Width = ElementCount::get(Width, IsScalable);
200       return Result;
201     }
202   };
203 
204   /// Return the IIT table descriptor for the specified intrinsic into an array
205   /// of IITDescriptors.
206   void getIntrinsicInfoTableEntries(ID id, SmallVectorImpl<IITDescriptor> &T);
207 
208   enum MatchIntrinsicTypesResult {
209     MatchIntrinsicTypes_Match = 0,
210     MatchIntrinsicTypes_NoMatchRet = 1,
211     MatchIntrinsicTypes_NoMatchArg = 2,
212   };
213 
214   /// Match the specified function type with the type constraints specified by
215   /// the .td file. If the given type is an overloaded type it is pushed to the
216   /// ArgTys vector.
217   ///
218   /// Returns false if the given type matches with the constraints, true
219   /// otherwise.
220   MatchIntrinsicTypesResult
221   matchIntrinsicSignature(FunctionType *FTy, ArrayRef<IITDescriptor> &Infos,
222                           SmallVectorImpl<Type *> &ArgTys);
223 
224   /// Verify if the intrinsic has variable arguments. This method is intended to
225   /// be called after all the fixed arguments have been matched first.
226   ///
227   /// This method returns true on error.
228   bool matchIntrinsicVarArg(bool isVarArg, ArrayRef<IITDescriptor> &Infos);
229 
230   /// Gets the type arguments of an intrinsic call by matching type contraints
231   /// specified by the .td file. The overloaded types are pushed into the
232   /// AgTys vector.
233   ///
234   /// Returns false if the given function is not a valid intrinsic call.
235   bool getIntrinsicSignature(Function *F, SmallVectorImpl<Type *> &ArgTys);
236 
237   // Checks if the intrinsic name matches with its signature and if not
238   // returns the declaration with the same signature and remangled name.
239   // An existing GlobalValue with the wanted name but with a wrong prototype
240   // or of the wrong kind will be renamed by adding ".renamed" to the name.
241   std::optional<Function *> remangleIntrinsicFunction(Function *F);
242 
243 } // End Intrinsic namespace
244 
245 } // End llvm namespace
246 
247 #endif
248