[OpenCL] Add generic type handling for builtin functions

Generic types are an abstraction of type sets.  It mimics the way
functions are defined in the OpenCL specification.  For example,
floatN can abstract all the vector sizes of the float type.

This allows to
 * stick more closely to the specification, which uses generic types;
 * factorize definitions of functions with numerous prototypes in the
   tablegen file; and
 * reduce the memory impact of functions with many overloads.

Patch by Pierre Gondois and Sven van Haastregt.

Differential Revision: https://reviews.llvm.org/D65456

llvm-svn: 369253

2 files changed, 266 insertions, 146 deletions

diff --git a/clang/lib/Sema/OpenCLBuiltins.td b/clang/lib/Sema/OpenCLBuiltins.td
index 645bb2cc654..c99d5073ef2 100644
--- a/clang/lib/Sema/OpenCLBuiltins.td
+++ b/clang/lib/Sema/OpenCLBuiltins.td
@@ -40,11 +40,15 @@ def LocalAS      : AddressSpace<"clang::LangAS::opencl_local">;
 def GenericAS    : AddressSpace<"clang::LangAS::opencl_generic">;
 
 
-// Qualified Type. Allow to retrieve one ASTContext QualType.
-class QualType<string _Name> {
+// Qualified Type.  These map to ASTContext::QualType.
+class QualType<string _Name, bit _IsAbstract=0> {
   // Name of the field or function in a clang::ASTContext
   // E.g. Name="IntTy" for the int type, and "getIntPtrType()" for an intptr_t
   string Name = _Name;
+  // Some QualTypes in this file represent an abstract type for which there is
+  // no corresponding AST QualType, e.g. a GenType or an `image2d_t` type
+  // without access qualifiers.
+  bit IsAbstract = _IsAbstract;
 }
 
 // Helper class to store type access qualifiers (volatile, const, ...).
@@ -52,25 +56,35 @@ class Qualifier<string _QualName> {
   string QualName = _QualName;
 }
 
+// List of integers.
+class IntList<string _Name, list<int> _List> {
+  string Name = _Name;
+  list<int> List = _List;
+}
+
 //===----------------------------------------------------------------------===//
 //                      OpenCL C classes for types
 //===----------------------------------------------------------------------===//
-// OpenCL types (int, float, ...)
+// OpenCL C basic data types (int, float, image2d_t, ...).
+// Its Child classes can represent concrete types (e.g.: VectorType) or
+// custom types (e.g.: GenType).
+// Instances of these child classes should be used in Builtin function
+// arguments.  See the definition of the "read_imagef" function as example.
 class Type<string _Name, QualType _QTName> {
-  // Name of the Type
+  // Name of the Type.
   string Name = _Name;
-  // QualType associated with this type
+  // QualType associated with this type.
   QualType QTName = _QTName;
-  // Size of the vector (if applicable)
-  int VecWidth = 0;
-  // Is pointer
+  // Size of the vector (if applicable).
+  int VecWidth = 1;
+  // Is a pointer.
   bit IsPointer = 0;
   // List of qualifiers associated with the type (volatile, ...)
   list<Qualifier> QualList = [];
-  // Address space
-  string AddrSpace = "clang::LangAS::Default";
   // Access qualifier. Must be one of ("RO", "WO", "RW").
   string AccessQualifier = "";
+  // Address space.
+  string AddrSpace = "clang::LangAS::Default";
 }
 
 // OpenCL vector types (e.g. int2, int3, int16, float8, ...)
@@ -78,7 +92,7 @@ class VectorType<Type _Ty, int _VecWidth> : Type<_Ty.Name, _Ty.QTName> {
   int VecWidth = _VecWidth;
 }
 
-// OpenCL pointer types (e.g. int*, float*, ...)
+// OpenCL pointer types (e.g. int*, float*, ...).
 class PointerType<Type _Ty, AddressSpace _AS = GlobalAS> :
                                       Type<_Ty.Name, _Ty.QTName> {
   bit IsPointer = 1;
@@ -91,6 +105,50 @@ class ImageType<Type _Ty, QualType _QTName, string _AccessQualifier> :
   let AccessQualifier = _AccessQualifier;
 }
 
+// List of Types.
+class TypeList<string _Name, list<Type> _Type> {
+  string Name = _Name;
+  list<Type> List = _Type;
+}
+
+// A GenericType is an abstract type that defines a set of types as a
+// combination of Types and vector sizes.
+//
+// E.g.: If TypeList = <int, float> and VectorList = <1, 2, 4>, then it
+//       represents <int, int2, int4, float, float2, float4>.
+// _Ty          : Name of the GenType.
+// _TypeList    : List of basic data Types.
+// _VectorList  : Sizes of the vector for each type of the _TypeList, 1 being a
+//                scalar.
+//
+// Some rules apply when using multiple GenericType arguments in a declaration:
+//   1. The number of vector sizes must be equal or 1 for all gentypes in a
+//      declaration.
+//   2. The number of Types must be equal or 1 for all gentypes in a
+//      declaration.
+//   3. Generic types are combined by iterating over all generic types at once.
+//      For example, for the following GenericTypes
+//        GenT1 = GenericType<half, [1, 2]> and
+//        GenT2 = GenericType<float, int, [1, 2]>
+//      A declaration f(GenT1, GenT2) results in the combinations
+//        f(half, float), f(half2, float2), f(half, int), f(half2, int2) .
+//   4. "sgentype" from the OpenCL specification is supported by specifying
+//      a single vector size.
+//      For example, for the following GenericTypes
+//        GenT = GenericType<half, int, [1, 2]> and
+//        SGenT = GenericType<half, int, [1]>
+//      A declaration f(GenT, SGenT) results in the combinations
+//        f(half, half), f(half2, half), f(int, int), f(int2, int) .
+class GenericType<string _Ty, TypeList _TypeList, IntList _VectorList> :
+                                            Type<_Ty, QualType<"null", 1>> {
+  // Possible element types of the generic type.
+  TypeList TypeList = _TypeList;
+  // Possible vector sizes of the types in the TypeList.
+  IntList VectorList = _VectorList;
+  // The VecWidth field is ignored for GenericTypes. Use VectorList instead.
+  let VecWidth = 0;
+}
+
 //===----------------------------------------------------------------------===//
 //                      OpenCL C class for builtin functions
 //===----------------------------------------------------------------------===//
@@ -108,54 +166,10 @@ class Builtin<string _Name, list<Type> _Signature> {
 }
 
 //===----------------------------------------------------------------------===//
-//                           Multiclass definitions
-//===----------------------------------------------------------------------===//
-// multiclass BifN: Creates Builtin class instances for OpenCL builtin
-//                  functions with N arguments.
-// _Name      : Name of the function
-// _Signature : Signature of the function (list of the Type used by the
-//              function, the first one being the return type).
-// _IsVector  : List of bit indicating if the type in the _Signature at the
-//              same index is to be a vector in the multiple overloads. The
-//              list must have at least one non-zero value.
-multiclass Bif0<string _Name, list<Type> _Signature, list<bit> _IsVector> {
-  def : Builtin<_Name, _Signature>;
-  foreach v = [2, 3, 4, 8, 16] in {
-    def : Builtin<_Name,
-                  [!if(_IsVector[0], VectorType<_Signature[0], v>, _Signature[0])]>;
-  }
-}
-multiclass Bif1<string _Name, list<Type> _Signature, list<bit> _IsVector> {
-  def : Builtin<_Name, _Signature>;
-  foreach v = [2, 3, 4, 8, 16] in {
-    def : Builtin<_Name,
-                  [!if(_IsVector[0], VectorType<_Signature[0], v>, _Signature[0]),
-                  !if(_IsVector[1], VectorType<_Signature[1], v>, _Signature[1])]>;
-  }
-}
-multiclass Bif2<string _Name, list<Type> _Signature, list<bit> _IsVector> {
-  def : Builtin<_Name, _Signature>;
-  foreach v = [2, 3, 4, 8, 16] in {
-    def : Builtin<_Name,
-                  [!if(_IsVector[0], VectorType<_Signature[0], v>, _Signature[0]),
-                  !if(_IsVector[1], VectorType<_Signature[1], v>, _Signature[1]),
-                  !if(_IsVector[2], VectorType<_Signature[2], v>, _Signature[2])]>;
-  }
-}
-multiclass Bif3<string _Name, list<Type> _Signature, list<bit> _IsVector> {
-  def : Builtin<_Name, _Signature>;
-  foreach v = [2, 3, 4, 8, 16] in {
-    def : Builtin<_Name,
-                  [!if(_IsVector[0], VectorType<_Signature[0], v>, _Signature[0]),
-                  !if(_IsVector[1], VectorType<_Signature[1], v>, _Signature[1]),
-                  !if(_IsVector[2], VectorType<_Signature[2], v>, _Signature[2]),
-                  !if(_IsVector[3], VectorType<_Signature[3], v>, _Signature[3])]>;
-  }
-}
-//===----------------------------------------------------------------------===//
 //                 Definitions of OpenCL C types
 //===----------------------------------------------------------------------===//
-// OpenCL v1.2 s6.1.1: Built-in Scalar Data Types
+
+// OpenCL v1.0/1.2/2.0 s6.1.1: Built-in Scalar Data Types.
 def Bool      : Type<"bool",      QualType<"BoolTy">>;
 def Char      : Type<"char",      QualType<"CharTy">>;
 def UChar     : Type<"uchar",     QualType<"UnsignedCharTy">>;
@@ -174,30 +188,18 @@ def IntPtr    : Type<"intptr_t",  QualType<"getIntPtrType()">>;
 def UIntPtr   : Type<"uintPtr_t", QualType<"getUIntPtrType()">>;
 def Void      : Type<"void_t",    QualType<"VoidTy">>;
 
-// OpenCL v1.2 s6.1.2: Built-in Vector Data Types
-foreach v = [2, 3, 4, 8, 16] in {
-  def char#v#_t    : VectorType<Char, v>;
-  def uchar#v#_t   : VectorType<UChar, v>;
-  def short#v#_t   : VectorType<Short, v>;
-  def ushort#v#_t  : VectorType<UShort, v>;
-  def "int"#v#_t   : VectorType<Int, v>;
-  def uint#v#_t    : VectorType<UInt, v>;
-  def long#v#_t    : VectorType<Long, v>;
-  def ulong#v#_t   : VectorType<ULong, v>;
-  def float#v#_t   : VectorType<Float, v>;
-  def double#v#_t  : VectorType<Double, v>;
-  def half#v#_t    : VectorType<Half, v>;
-}
+// OpenCL v1.0/1.2/2.0 s6.1.2: Built-in Vector Data Types.
+// Built-in vector data types are created by TableGen's OpenCLBuiltinEmitter.
 
 // OpenCL v1.2 s6.1.3: Other Built-in Data Types
 // These definitions with a "null" name are "abstract". They should not
 // be used in definitions of Builtin functions.
-def image2d_t         : Type<"image2d_t", QualType<"null">>;
-def image3d_t         : Type<"image3d_t", QualType<"null">>;
-def image2d_array_t   : Type<"image2d_array_t", QualType<"null">>;
-def image1d_t         : Type<"image1d_t", QualType<"null">>;
-def image1d_buffer_t  : Type<"image1d_buffer_t", QualType<"null">>;
-def image1d_array_t   : Type<"image1d_array_t", QualType<"null">>;
+def image2d_t         : Type<"image2d_t", QualType<"null", 1>>;
+def image3d_t         : Type<"image3d_t", QualType<"null", 1>>;
+def image2d_array_t   : Type<"image2d_array_t", QualType<"null", 1>>;
+def image1d_t         : Type<"image1d_t", QualType<"null", 1>>;
+def image1d_buffer_t  : Type<"image1d_buffer_t", QualType<"null", 1>>;
+def image1d_array_t   : Type<"image1d_array_t", QualType<"null", 1>>;
 // Unlike the few functions above, the following definitions can be used
 // in definitions of Builtin functions (they have a QualType with a name).
 foreach v = ["RO", "WO", "RW"] in {
@@ -225,6 +227,49 @@ def Sampler           : Type<"Sampler", QualType<"OCLSamplerTy">>;
 def Event             : Type<"Event", QualType<"OCLEventTy">>;
 
 //===----------------------------------------------------------------------===//
+//                 Definitions of OpenCL gentype variants
+//===----------------------------------------------------------------------===//
+// The OpenCL specification often uses "gentype" in builtin function
+// declarations to indicate that a builtin function is available with various
+// argument and return types.  The types represented by "gentype" vary between
+// different parts of the specification.  The following definitions capture
+// the different type lists for gentypes in different parts of the
+// specification.
+
+// Vector width lists.
+def VecAndScalar: IntList<"VecAndScalar", [1, 2, 3, 4, 8, 16]>;
+def VecNoScalar : IntList<"VecNoScalar", [2, 3, 4, 8, 16]>;
+def Vec1        : IntList<"Vec1", [1]>;
+
+// Type lists.
+def TLFloat : TypeList<"TLFloat", [Float, Double, Half]>;
+
+def TLAllInts : TypeList<"TLAllInts", [Char, UChar, Short, UShort, Int, UInt, Long, ULong]>;
+
+// GenType definitions for multiple base types (e.g. all floating point types,
+// or all integer types).
+// All integer
+def AIGenType1             : GenericType<"AIGenType1", TLAllInts, Vec1>;
+def AIGenTypeN             : GenericType<"AIGenTypeN", TLAllInts, VecAndScalar>;
+def AIGenTypeNNoScalar     : GenericType<"AIGenTypeNNoScalar", TLAllInts, VecNoScalar>;
+// Float
+def FGenTypeN              : GenericType<"FGenTypeN", TLFloat, VecAndScalar>;
+
+// GenType definitions for every single base type (e.g. fp32 only).
+// Names are like: GenTypeFloatVecAndScalar.
+foreach Type = [Char, UChar, Short, UShort,
+                Int, UInt, Long, ULong,
+                Float, Double, Half] in {
+  foreach VecSizes = [VecAndScalar, VecNoScalar] in {
+    def "GenType" # Type # VecSizes :
+              GenericType<"GenType" # Type # VecSizes,
+                          TypeList<"GL" # Type.Name, [Type]>,
+                          VecSizes>;
+  }
+}
+
+
+//===----------------------------------------------------------------------===//
 //                 Definitions of OpenCL builtin functions
 //===----------------------------------------------------------------------===//
 //--------------------------------------------------------------------
@@ -261,27 +306,29 @@ foreach name = ["get_global_size", "get_global_id", "get_local_size",
 foreach name = ["acos", "acosh", "acospi",
                 "asin", "asinh", "asinpi",
                 "atan", "atanh", "atanpi"] in {
-  foreach type = [Float, Double, Half] in {
-    defm : Bif1<name, [type, type], [1, 1]>;
-  }
+  def : Builtin<name, [FGenTypeN, FGenTypeN]>;
 }
 
 foreach name = ["atan2", "atan2pi"] in {
-  foreach type = [Float, Double, Half] in {
-    defm : Bif2<name, [type, type, type], [1, 1, 1]>;
-  }
+  def : Builtin<name, [FGenTypeN, FGenTypeN, FGenTypeN]>;
 }
 
 foreach name = ["fmax", "fmin"] in {
-  foreach type = [Float, Double, Half] in {
-    defm : Bif2<name, [type, type, type], [1, 1, 1]>;
-    defm : Bif2<name, [type, type, type], [1, 1, 0]>;
-  }
+  def : Builtin<name, [FGenTypeN, FGenTypeN, FGenTypeN]>;
+  def : Builtin<name, [GenTypeFloatVecNoScalar, GenTypeFloatVecNoScalar, Float]>;
+  def : Builtin<name, [GenTypeDoubleVecNoScalar, GenTypeDoubleVecNoScalar, Double]>;
+  def : Builtin<name, [GenTypeHalfVecNoScalar, GenTypeHalfVecNoScalar, Half]>;
+}
+
+// OpenCL v1.1 s6.11.3, v1.2 s6.12.3, v2.0 s6.13.3 - Integer Functions
+foreach name = ["max", "min"] in {
+  def : Builtin<name, [AIGenTypeN, AIGenTypeN, AIGenTypeN]>;
+  def : Builtin<name, [AIGenTypeNNoScalar, AIGenTypeNNoScalar, AIGenType1]>;
 }
 
 // OpenCL v1.2 s6.12.14: Built-in Image Read Functions
 def read_imagef : Builtin<"read_imagef",
-                          [float4_t, image2d_RO_t, VectorType<Int, 2>]>;
+                          [VectorType<Float, 4>, image2d_RO_t, VectorType<Int, 2>]>;
 def write_imagef : Builtin<"write_imagef",
                            [Void,
                             image2d_WO_t,
diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index 5127ce026c8..525f921b297 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -673,76 +673,148 @@ LLVM_DUMP_METHOD void LookupResult::dump() {
     D->dump();
 }
 
-/// When trying to resolve a function name, if the isOpenCLBuiltin function
-/// defined in "OpenCLBuiltins.inc" returns a non-null <Index, Len>, then the
-/// identifier is referencing an OpenCL builtin function. Thus, all its
-/// prototypes are added to the LookUpResult.
-///
-/// \param S The Sema instance
-/// \param LR  The LookupResult instance
-/// \param II  The identifier being resolved
-/// \param Index  The list of prototypes starts at Index in OpenCLBuiltins[]
-/// \param Len  The list of prototypes has Len elements
-static void InsertOCLBuiltinDeclarations(Sema &S, LookupResult &LR,
-                                         IdentifierInfo *II, unsigned Index,
-                                         unsigned Len) {
-
-  for (unsigned i = 0; i < Len; ++i) {
-    const OpenCLBuiltinDecl &Decl = OpenCLBuiltins[Index - 1 + i];
-    ASTContext &Context = S.Context;
+/// Get the QualType instances of the return type and arguments for an OpenCL
+/// builtin function signature.
+/// \param Context (in) The Context instance.
+/// \param OpenCLBuiltin (in) The signature currently handled.
+/// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic
+///        type used as return type or as argument.
+///        Only meaningful for generic types, otherwise equals 1.
+/// \param RetTypes (out) List of the possible return types.
+/// \param ArgTypes (out) List of the possible argument types.  For each
+///        argument, ArgTypes contains QualTypes for the Cartesian product
+///        of (vector sizes) x (types) .
+static void GetQualTypesForOpenCLBuiltin(
+    ASTContext &Context, const OpenCLBuiltinStruct &OpenCLBuiltin,
+    unsigned &GenTypeMaxCnt, std::vector<QualType> &RetTypes,
+    SmallVector<std::vector<QualType>, 5> &ArgTypes) {
+  // Get the QualType instances of the return types.
+  unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex];
+  OCL2Qual(Context, TypeTable[Sig], RetTypes);
+  GenTypeMaxCnt = RetTypes.size();
+
+  // Get the QualType instances of the arguments.
+  // First type is the return type, skip it.
+  for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) {
+    std::vector<QualType> Ty;
+    OCL2Qual(Context,
+        TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]], Ty);
+    ArgTypes.push_back(Ty);
+    GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt;
+  }
+}
 
-    // Ignore this BIF if the version is incorrect.
-    if (Context.getLangOpts().OpenCLVersion < Decl.Version)
-      continue;
+/// Create a list of the candidate function overloads for an OpenCL builtin
+/// function.
+/// \param Context (in) The ASTContext instance.
+/// \param GenTypeMaxCnt (in) Maximum number of types contained in a generic
+///        type used as return type or as argument.
+///        Only meaningful for generic types, otherwise equals 1.
+/// \param FunctionList (out) List of FunctionTypes.
+/// \param RetTypes (in) List of the possible return types.
+/// \param ArgTypes (in) List of the possible types for the arguments.
+static void
+GetOpenCLBuiltinFctOverloads(ASTContext &Context, unsigned GenTypeMaxCnt,
+                             std::vector<QualType> &FunctionList,
+                             std::vector<QualType> &RetTypes,
+                             SmallVector<std::vector<QualType>, 5> &ArgTypes) {
+  FunctionProtoType::ExtProtoInfo PI;
+  PI.Variadic = false;
+
+  // Create FunctionTypes for each (gen)type.
+  for (unsigned IGenType = 0; IGenType < GenTypeMaxCnt; IGenType++) {
+    SmallVector<QualType, 5> ArgList;
+
+    for (unsigned A = 0; A < ArgTypes.size(); A++) {
+      // Builtins such as "max" have an "sgentype" argument that represents
+      // the corresponding scalar type of a gentype.  The number of gentypes
+      // must be a multiple of the number of sgentypes.
+      assert(GenTypeMaxCnt % ArgTypes[A].size() == 0 &&
+             "argument type count not compatible with gentype type count");
+      unsigned Idx = IGenType % ArgTypes[A].size();
+      ArgList.push_back(ArgTypes[A][Idx]);
+    }
 
-    FunctionProtoType::ExtProtoInfo PI;
-    PI.Variadic = false;
+    FunctionList.push_back(Context.getFunctionType(
+        RetTypes[(RetTypes.size() != 1) ? IGenType : 0], ArgList, PI));
+  }
+}
 
-    // Defined in "OpenCLBuiltins.inc"
-    QualType RT = OCL2Qual(Context, OpenCLSignature[Decl.ArgTableIndex]);
+/// When trying to resolve a function name, if isOpenCLBuiltin() returns a
+/// non-null <Index, Len> pair, then the name is referencing an OpenCL
+/// builtin function.  Add all candidate signatures to the LookUpResult.
+///
+/// \param S (in) The Sema instance.
+/// \param LR (inout) The LookupResult instance.
+/// \param II (in) The identifier being resolved.
+/// \param FctIndex (in) Starting index in the BuiltinTable.
+/// \param Len (in) The signature list has Len elements.
+static void InsertOCLBuiltinDeclarationsFromTable(Sema &S, LookupResult &LR,
+                                                  IdentifierInfo *II,
+                                                  const unsigned FctIndex,
+                                                  const unsigned Len) {
+  // The builtin function declaration uses generic types (gentype).
+  bool HasGenType = false;
+
+  // Maximum number of types contained in a generic type used as return type or
+  // as argument.  Only meaningful for generic types, otherwise equals 1.
+  unsigned GenTypeMaxCnt;
+
+  for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) {
+    const OpenCLBuiltinStruct &OpenCLBuiltin =
+        BuiltinTable[FctIndex + SignatureIndex];
+    ASTContext &Context = S.Context;
+
+    std::vector<QualType> RetTypes;
+    SmallVector<std::vector<QualType>, 5> ArgTypes;
 
-    SmallVector<QualType, 5> ArgTypes;
-    for (unsigned I = 1; I < Decl.NumArgs; I++) {
-      QualType Ty = OCL2Qual(Context, OpenCLSignature[Decl.ArgTableIndex + I]);
-      ArgTypes.push_back(Ty);
+    // Obtain QualType lists for the function signature.
+    GetQualTypesForOpenCLBuiltin(Context, OpenCLBuiltin, GenTypeMaxCnt,
+                                 RetTypes, ArgTypes);
+    if (GenTypeMaxCnt > 1) {
+      HasGenType = true;
     }
 
-    QualType R = Context.getFunctionType(RT, ArgTypes, PI);
-    SourceLocation Loc = LR.getNameLoc();
+    // Create function overload for each type combination.
+    std::vector<QualType> FunctionList;
+    GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes,
+                                 ArgTypes);
 
-    // TODO: This part is taken from Sema::LazilyCreateBuiltin,
-    // maybe refactor it.
+    SourceLocation Loc = LR.getNameLoc();
     DeclContext *Parent = Context.getTranslationUnitDecl();
-    FunctionDecl *New = FunctionDecl::Create(Context, Parent, Loc, Loc, II, R,
-                                             /*TInfo=*/nullptr, SC_Extern,
-                                             false, R->isFunctionProtoType());
-    New->setImplicit();
-
-    // Create Decl objects for each parameter, adding them to the
-    // FunctionDecl.
-    if (const FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) {
-      SmallVector<ParmVarDecl *, 16> Params;
-      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
-        ParmVarDecl *Parm =
-            ParmVarDecl::Create(Context, New, SourceLocation(),
-                                SourceLocation(), nullptr, FT->getParamType(i),
-                                /*TInfo=*/nullptr, SC_None, nullptr);
-        Parm->setScopeInfo(0, i);
-        Params.push_back(Parm);
+    FunctionDecl *NewOpenCLBuiltin;
+
+    for (unsigned Index = 0; Index < GenTypeMaxCnt; Index++) {
+      NewOpenCLBuiltin = FunctionDecl::Create(
+          Context, Parent, Loc, Loc, II, FunctionList[Index],
+          /*TInfo=*/nullptr, SC_Extern, false,
+          FunctionList[Index]->isFunctionProtoType());
+      NewOpenCLBuiltin->setImplicit();
+
+      // Create Decl objects for each parameter, adding them to the
+      // FunctionDecl.
+      if (const FunctionProtoType *FP =
+              dyn_cast<FunctionProtoType>(FunctionList[Index])) {
+        SmallVector<ParmVarDecl *, 16> ParmList;
+        for (unsigned IParm = 0, e = FP->getNumParams(); IParm != e; ++IParm) {
+          ParmVarDecl *Parm = ParmVarDecl::Create(
+              Context, NewOpenCLBuiltin, SourceLocation(), SourceLocation(),
+              nullptr, FP->getParamType(IParm),
+              /*TInfo=*/nullptr, SC_None, nullptr);
+          Parm->setScopeInfo(0, IParm);
+          ParmList.push_back(Parm);
+        }
+        NewOpenCLBuiltin->setParams(ParmList);
       }
-      New->setParams(Params);
+      if (!S.getLangOpts().OpenCLCPlusPlus) {
+        NewOpenCLBuiltin->addAttr(OverloadableAttr::CreateImplicit(Context));
+      }
+      LR.addDecl(NewOpenCLBuiltin);
     }
-
-    New->addAttr(OverloadableAttr::CreateImplicit(Context));
-
-    if (strlen(Decl.Extension))
-      S.setOpenCLExtensionForDecl(New, Decl.Extension);
-
-    LR.addDecl(New);
   }
 
   // If we added overloads, need to resolve the lookup result.
-  if (Len > 1)
+  if (Len > 1 || HasGenType)
     LR.resolveKind();
 }
 
@@ -772,7 +844,8 @@ static bool LookupBuiltin(Sema &S, LookupResult &R) {
       if (S.getLangOpts().OpenCL && S.getLangOpts().DeclareOpenCLBuiltins) {
         auto Index = isOpenCLBuiltin(II->getName());
         if (Index.first) {
-          InsertOCLBuiltinDeclarations(S, R, II, Index.first, Index.second);
+          InsertOCLBuiltinDeclarationsFromTable(S, R, II, Index.first - 1,
+                                                Index.second);
           return true;
         }
       }