[ARM] Add __bf16 as new Bfloat16 C Type

[stuij]

Summary

This patch upstreams support for a new storage only bfloat16 C type.
This type is used to implement primitive support for bfloat16 data, in
line with the Bfloat16 extension of the Armv8.6-a architecture, as
detailed here:

https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a

The bfloat type, and its properties is specified in the Arm C language
extension specification:

https://developer.arm.com/docs/ihi0055/d/procedure-call-standard-for-the-arm-64-bit-architecture

In detail this patch:

introduces an opaque, storage-only C-type __bf16, which does not introduce a new LLVM IR type, but maps it to either i16 or half type.

This is part of a patch series, starting with command-line and Bfloat16
assembly support. The subsequent patches will upstream intrinsics
support for BFloat16, followed by Matrix Multiplication and the
remaining Virtualization features of the armv8.6-a architecture.

Based on work by:

• Luke Cheeseman
• Momchil Velikov
• labrinea
• Luke Geeson

[stuij]

changes: depend on bfloat IR type, and resolve some conflicts that crept in

[stuij]

This should not have been it's own revision. I wrongly trusted arc to update https://reviews.llvm.org/D76077.

clang/docs/LanguageExtensions.rst

 .. [#] unary operator ! is not implemented, however && and || are.
 .. [#] While OpenCL and GCC vectors both implement the comparison operator(?:) as a
   'select', they operate somewhat differently. OpenCL selects based on signedness of
   the condition operands, but GCC vectors use normal bool conversions (that is, != 0).
 
 Half-Precision Floating Point
 =============================
 
-Clang supports two half-precision (16-bit) floating point types: ``__fp16`` and
-``_Float16``.  These types are supported in all language modes.
+Clang supports three half-precision (16-bit) floating point types: ``__fp16``,
+``_Float16`` and ``__bf16``.  These types are supported in all language modes.
 
 ``__fp16`` is supported on every target, as it is purely a storage format; see below.
 ``_Float16`` is currently only supported on the following targets, with further
 targets pending ABI standardization:
 
 * 32-bit ARM
 * 64-bit ARM (AArch64)
 * SPIR
 
 ``_Float16`` will be supported on more targets as they define ABIs for it.
 
+``__bf16`` is purely a storage format; it is currently only supported on the following targets:
+* 32-bit ARM
+* 64-bit ARM (AArch64)
+
 ``__fp16`` is a storage and interchange format only.  This means that values of
 ``__fp16`` are immediately promoted to (at least) ``float`` when used in arithmetic
 operations, so that e.g. the result of adding two ``__fp16`` values has type ``float``.
 The behavior of ``__fp16`` is specified by the ARM C Language Extensions (`ACLE <http://infocenter.arm.com/help/topic/com.arm.doc.ihi0053d/IHI0053D_acle_2_1.pdf>`_).
 Clang uses the ``binary16`` format from IEEE 754-2008 for ``__fp16``, not the ARM
 alternative format.
 
 ``_Float16`` is an extended floating-point type.  This means that, just like arithmetic on

clang/include/clang-c/Index.h

 /*===-- clang-c/Index.h - Indexing Public C Interface -------------*- C -*-===*\
 |*                                                                            *|
 |* Part of the LLVM Project, under the Apache License v2.0 with LLVM          *|
 |* Exceptions.                                                                *|
 |* See https://llvm.org/LICENSE.txt for license information.                  *|
 |* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception                    *|
 |*                                                                            *|
 |*===----------------------------------------------------------------------===*|
enum CXTypeKind {
   CXType_Half = 31,
   CXType_Float16 = 32,
   CXType_ShortAccum = 33,
   CXType_Accum = 34,
   CXType_LongAccum = 35,
   CXType_UShortAccum = 36,
   CXType_UAccum = 37,
   CXType_ULongAccum = 38,
+  CXType_Bfloat16 = 39,
   CXType_FirstBuiltin = CXType_Void,
   CXType_LastBuiltin = CXType_ULongAccum,
 
   CXType_Complex = 100,
   CXType_Pointer = 101,
   CXType_BlockPointer = 102,
   CXType_LValueReference = 103,
   CXType_RValueReference = 104,

clang/include/clang/AST/ASTContext.h

 //===- ASTContext.h - Context to hold long-lived AST nodes ------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
public:
   CanQualType UnsignedShortFractTy, UnsignedFractTy, UnsignedLongFractTy;
   CanQualType SatShortAccumTy, SatAccumTy, SatLongAccumTy;
   CanQualType SatUnsignedShortAccumTy, SatUnsignedAccumTy,
       SatUnsignedLongAccumTy;
   CanQualType SatShortFractTy, SatFractTy, SatLongFractTy;
   CanQualType SatUnsignedShortFractTy, SatUnsignedFractTy,
       SatUnsignedLongFractTy;
   CanQualType HalfTy; // [OpenCL 6.1.1.1], ARM NEON
+  CanQualType Bfloat16Ty; // ARM NEON
   CanQualType Float16Ty; // C11 extension ISO/IEC TS 18661-3
   CanQualType FloatComplexTy, DoubleComplexTy, LongDoubleComplexTy;
   CanQualType Float128ComplexTy;
   CanQualType VoidPtrTy, NullPtrTy;
   CanQualType DependentTy, OverloadTy, BoundMemberTy, UnknownAnyTy;
   CanQualType BuiltinFnTy;
   CanQualType PseudoObjectTy, ARCUnbridgedCastTy;
   CanQualType ObjCBuiltinIdTy, ObjCBuiltinClassTy, ObjCBuiltinSelTy;

clang/include/clang/AST/BuiltinTypes.def

 FLOATING_TYPE(Double, DoubleTy)
 
 // 'long double'
 FLOATING_TYPE(LongDouble, LongDoubleTy)
 
 // '_Float16'
 FLOATING_TYPE(Float16, HalfTy)
 
+// '__bf16'
+FLOATING_TYPE(Bfloat16, Bfloat16Ty)
+
 // '__float128'
 FLOATING_TYPE(Float128, Float128Ty)
 
 //===- Language-specific types --------------------------------------------===//
 
 // This is the type of C++0x 'nullptr'.
 BUILTIN_TYPE(NullPtr, NullPtrTy)
 

clang/include/clang/AST/Type.h

 //===- Type.h - C Language Family Type Representation -----------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
public:
   bool isRealFloatingType() const; // C99 6.2.5p10 (float, double, long double)
   /// isComplexType() does *not* include complex integers (a GCC extension).
   /// isComplexIntegerType() can be used to test for complex integers.
   bool isComplexType() const;      // C99 6.2.5p11 (complex)
   bool isAnyComplexType() const;   // C99 6.2.5p11 (complex) + Complex Int.
   bool isFloatingType() const;     // C99 6.2.5p11 (real floating + complex)
   bool isHalfType() const;         // OpenCL 6.1.1.1, NEON (IEEE 754-2008 half)
   bool isFloat16Type() const;      // C11 extension ISO/IEC TS 18661
+  bool isBFloat16Type() const;     // ARM BFloat
   bool isFloat128Type() const;
   bool isRealType() const;         // C99 6.2.5p17 (real floating + integer)
   bool isArithmeticType() const;   // C99 6.2.5p18 (integer + floating)
   bool isVoidType() const;         // C99 6.2.5p19
   bool isScalarType() const;       // C99 6.2.5p21 (arithmetic + pointers)
   bool isAggregateType() const;
   bool isFundamentalType() const;
   bool isCompoundType() const;
inline bool Type::isHalfType() const {
   // FIXME: Should we allow complex __fp16? Probably not.
   return isSpecificBuiltinType(BuiltinType::Half);
 }
 
 inline bool Type::isFloat16Type() const {
   return isSpecificBuiltinType(BuiltinType::Float16);
 }
 
+inline bool Type::isBFloat16Type() const {
+  return isSpecificBuiltinType(BuiltinType::Bfloat16);
+}
+
 inline bool Type::isFloat128Type() const {
   return isSpecificBuiltinType(BuiltinType::Float128);
 }
 
 inline bool Type::isNullPtrType() const {
   return isSpecificBuiltinType(BuiltinType::NullPtr);
 }
 

clang/include/clang/Basic/Specifiers.h

 //===--- Specifiers.h - Declaration and Type Specifiers ---------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 ///
enum TypeSpecifierType {
     TST_char16,       // C++11 char16_t
     TST_char32,       // C++11 char32_t
     TST_int,
     TST_int128,
     TST_half,         // OpenCL half, ARM NEON __fp16
     TST_Float16,      // C11 extension ISO/IEC TS 18661-3
     TST_Accum,        // ISO/IEC JTC1 SC22 WG14 N1169 Extension
     TST_Fract,
+    TST_Bfloat16,
     TST_float,
     TST_double,
     TST_float128,
     TST_bool,         // _Bool
     TST_decimal32,    // _Decimal32
     TST_decimal64,    // _Decimal64
     TST_decimal128,   // _Decimal128
     TST_enum,

clang/include/clang/Basic/TargetBuiltins.h

 //===--- TargetBuiltins.h - Target specific builtin IDs ---------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 ///
enum EltType {
       Int32,
       Int64,
       Poly8,
       Poly16,
       Poly64,
       Poly128,
       Float16,
       Float32,
-      Float64
+      Float64,
+      Bfloat16
     };
 
     NeonTypeFlags(unsigned F) : Flags(F) {}
     NeonTypeFlags(EltType ET, bool IsUnsigned, bool IsQuad) : Flags(ET) {
       if (IsUnsigned)
         Flags |= UnsignedFlag;
       if (IsQuad)
         Flags |= QuadFlag;

clang/include/clang/Basic/TargetInfo.h

 //===--- TargetInfo.h - Expose information about the target -----*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 ///

 /// Fields controlling how types are laid out in memory; these may need to
 /// be copied for targets like AMDGPU that base their ABIs on an auxiliary
 /// CPU target.
 struct TransferrableTargetInfo {
   unsigned char PointerWidth, PointerAlign;
   unsigned char BoolWidth, BoolAlign;
   unsigned char IntWidth, IntAlign;
   unsigned char HalfWidth, HalfAlign;
+  unsigned char Bfloat16Width, Bfloat16Align;
   unsigned char FloatWidth, FloatAlign;
   unsigned char DoubleWidth, DoubleAlign;
   unsigned char LongDoubleWidth, LongDoubleAlign, Float128Align;
   unsigned char LargeArrayMinWidth, LargeArrayAlign;
   unsigned char LongWidth, LongAlign;
   unsigned char LongLongWidth, LongLongAlign;
 
   // Fixed point bit widths
struct TransferrableTargetInfo {
   unsigned char SuitableAlign;
   unsigned char DefaultAlignForAttributeAligned;
   unsigned char MinGlobalAlign;
 
   unsigned short NewAlign;
   unsigned short MaxVectorAlign;
   unsigned short MaxTLSAlign;
 
-  const llvm::fltSemantics *HalfFormat, *FloatFormat, *DoubleFormat,
-    *LongDoubleFormat, *Float128Format;
+  const llvm::fltSemantics *HalfFormat, *Bfloat16Format, *FloatFormat,
+    *DoubleFormat, *LongDoubleFormat, *Float128Format;
 
   ///===---- Target Data Type Query Methods -------------------------------===//
   enum IntType {
     NoInt = 0,
     SignedChar,
     UnsignedChar,
     SignedShort,
     UnsignedShort,
protected:
   bool BigEndian;
   bool TLSSupported;
   bool VLASupported;
   bool NoAsmVariants;  // True if {|} are normal characters.
   bool HasLegalHalfType; // True if the backend supports operations on the half
                          // LLVM IR type.
   bool HasFloat128;
   bool HasFloat16;
+  bool HasBfloat16;
 
   unsigned char MaxAtomicPromoteWidth, MaxAtomicInlineWidth;
   unsigned short SimdDefaultAlign;
   std::unique_ptr<llvm::DataLayout> DataLayout;
   const char *MCountName;
   unsigned char RegParmMax, SSERegParmMax;
   TargetCXXABI TheCXXABI;
   const LangASMap *AddrSpaceMap;
public:
   virtual bool hasLegalHalfType() const { return HasLegalHalfType; }
 
   /// Determine whether the __float128 type is supported on this target.
   virtual bool hasFloat128Type() const { return HasFloat128; }
 
   /// Determine whether the _Float16 type is supported on this target.
   virtual bool hasFloat16Type() const { return HasFloat16; }
 
+  /// Determine whether the _Bfloat16 type is supported on this target.
+  virtual bool hasBfloat16Type() const { return HasBfloat16; }
+
   /// Return the alignment that is suitable for storing any
   /// object with a fundamental alignment requirement.
   unsigned getSuitableAlign() const { return SuitableAlign; }
 
   /// Return the default alignment for __attribute__((aligned)) on
   /// this target, to be used if no alignment value is specified.
   unsigned getDefaultAlignForAttributeAligned() const {
     return DefaultAlignForAttributeAligned;
public:
   unsigned getHalfAlign() const { return HalfAlign; }
   const llvm::fltSemantics &getHalfFormat() const { return *HalfFormat; }
 
   /// getFloatWidth/Align/Format - Return the size/align/format of 'float'.
   unsigned getFloatWidth() const { return FloatWidth; }
   unsigned getFloatAlign() const { return FloatAlign; }
   const llvm::fltSemantics &getFloatFormat() const { return *FloatFormat; }
 
+  /// getBfloat16Width/Align/Format - Return the size/align/format of '__bf16'.
+  unsigned getBfloat16Width() const { return Bfloat16Width; }
+  unsigned getBfloat16Align() const { return Bfloat16Align; }
+  const llvm::fltSemantics &getBfloat16Format() const { return *Bfloat16Format; }
+
   /// getDoubleWidth/Align/Format - Return the size/align/format of 'double'.
   unsigned getDoubleWidth() const { return DoubleWidth; }
   unsigned getDoubleAlign() const { return DoubleAlign; }
   const llvm::fltSemantics &getDoubleFormat() const { return *DoubleFormat; }
 
   /// getLongDoubleWidth/Align/Format - Return the size/align/format of 'long
   /// double'.
   unsigned getLongDoubleWidth() const { return LongDoubleWidth; }
public:
   }
 
   /// Return the mangled code of long double.
   virtual const char *getLongDoubleMangling() const { return "e"; }
 
   /// Return the mangled code of __float128.
   virtual const char *getFloat128Mangling() const { return "g"; }
 
+  /// Return the mangled code of bfloat.
+  virtual const char *getBfloat16Mangling() const {
+    llvm_unreachable("bfloat not implemented on this target");
+  }
+
   /// Return the value for the C99 FLT_EVAL_METHOD macro.
   virtual unsigned getFloatEvalMethod() const { return 0; }
 
   // getLargeArrayMinWidth/Align - Return the minimum array size that is
   // 'large' and its alignment.
   unsigned getLargeArrayMinWidth() const { return LargeArrayMinWidth; }
   unsigned getLargeArrayAlign() const { return LargeArrayAlign; }
 

clang/include/clang/Basic/TokenKinds.def

 
 // Altivec Extension.
 KEYWORD(__vector                    , KEYALTIVEC|KEYZVECTOR)
 KEYWORD(__pixel                     , KEYALTIVEC)
 KEYWORD(__bool                      , KEYALTIVEC|KEYZVECTOR)
 
 // ARM NEON extensions.
 ALIAS("__fp16", half                , KEYALL)
+KEYWORD(__bf16                      , KEYALL)
 
 // OpenCL Extension.
 KEYWORD(half                        , HALFSUPPORT)
 
 // Objective-C ARC keywords.
 KEYWORD(__bridge                     , KEYOBJC)
 KEYWORD(__bridge_transfer            , KEYOBJC)
 KEYWORD(__bridge_retained            , KEYOBJC)

clang/include/clang/Sema/DeclSpec.h

 //===--- DeclSpec.h - Parsed declaration specifiers -------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 ///
public:
   static const TST TST_char = clang::TST_char;
   static const TST TST_wchar = clang::TST_wchar;
   static const TST TST_char8 = clang::TST_char8;
   static const TST TST_char16 = clang::TST_char16;
   static const TST TST_char32 = clang::TST_char32;
   static const TST TST_int = clang::TST_int;
   static const TST TST_int128 = clang::TST_int128;
   static const TST TST_half = clang::TST_half;
+  static const TST TST_Bfloat16 = clang::TST_Bfloat16;
   static const TST TST_float = clang::TST_float;
   static const TST TST_double = clang::TST_double;
   static const TST TST_float16 = clang::TST_Float16;
   static const TST TST_accum = clang::TST_Accum;
   static const TST TST_fract = clang::TST_Fract;
   static const TST TST_float128 = clang::TST_float128;
   static const TST TST_bool = clang::TST_bool;
   static const TST TST_decimal32 = clang::TST_decimal32;

clang/include/clang/Serialization/ASTBitCodes.h

 //===- ASTBitCodes.h - Enum values for the PCH bitcode format ---*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
enum PredefinedTypeIDs {
       PREDEF_TYPE_SAT_ULONG_FRACT_ID = 69,
 
       /// The placeholder type for OpenMP array shaping operation.
       PREDEF_TYPE_OMP_ARRAY_SHAPING = 70,
 
       /// The placeholder type for OpenMP iterator expression.
       PREDEF_TYPE_OMP_ITERATOR = 71,
 
+      /// \brief The '__bf16' type
+      PREDEF_TYPE_BFLOAT16_ID = 72,
+
       /// OpenCL image types with auto numeration
 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
       PREDEF_TYPE_##Id##_ID,
 #include "clang/Basic/OpenCLImageTypes.def"
       /// \brief OpenCL extension types with auto numeration
 #define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
       PREDEF_TYPE_##Id##_ID,
 #include "clang/Basic/OpenCLExtensionTypes.def"

clang/lib/AST/ASTContext.cpp

 //===- ASTContext.cpp - Context to hold long-lived AST nodes --------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //

 #include <memory>
 #include <string>
 #include <tuple>
 #include <utility>
 
 using namespace clang;
 
 enum FloatingRank {
-  Float16Rank, HalfRank, FloatRank, DoubleRank, LongDoubleRank, Float128Rank
+  Bfloat16Rank, Float16Rank, HalfRank, FloatRank, DoubleRank, LongDoubleRank, Float128Rank
 };
 
 /// \returns location that is relevant when searching for Doc comments related
 /// to \p D.
 static SourceLocation getDeclLocForCommentSearch(const Decl *D,
                                                  SourceManager &SourceMgr) {
   assert(D);
 
#include "clang/Basic/AArch64SVEACLETypes.def"
   }
 
   // nullptr type (C++0x 2.14.7)
   InitBuiltinType(NullPtrTy,           BuiltinType::NullPtr);
 
   // half type (OpenCL 6.1.1.1) / ARM NEON __fp16
   InitBuiltinType(HalfTy, BuiltinType::Half);
 
+  InitBuiltinType(Bfloat16Ty, BuiltinType::Bfloat16);
+
   // Builtin type used to help define __builtin_va_list.
   VaListTagDecl = nullptr;
 }
 
 DiagnosticsEngine &ASTContext::getDiagnostics() const {
   return SourceMgr.getDiagnostics();
 }
 

 //===----------------------------------------------------------------------===//
 
 /// getFloatTypeSemantics - Return the APFloat 'semantics' for the specified
 /// scalar floating point type.
 const llvm::fltSemantics &ASTContext::getFloatTypeSemantics(QualType T) const {
   switch (T->castAs<BuiltinType>()->getKind()) {
   default:
     llvm_unreachable("Not a floating point type!");
+  case BuiltinType::Bfloat16:
+    return Target->getBfloat16Format();
   case BuiltinType::Float16:
   case BuiltinType::Half:
     return Target->getHalfFormat();
   case BuiltinType::Float:      return Target->getFloatFormat();
   case BuiltinType::Double:     return Target->getDoubleFormat();
   case BuiltinType::LongDouble:
     if (getLangOpts().OpenMP && getLangOpts().OpenMPIsDevice)
       return AuxTarget->getLongDoubleFormat();
case BuiltinType::SatUFract:
       break;
     case BuiltinType::LongFract:
     case BuiltinType::ULongFract:
     case BuiltinType::SatLongFract:
     case BuiltinType::SatULongFract:
       Width = Target->getLongFractWidth();
       Align = Target->getLongFractAlign();
       break;
+    case BuiltinType::Bfloat16:
+      Width = Target->getBfloat16Width();
+      Align = Target->getBfloat16Align();
     case BuiltinType::Float16:
     case BuiltinType::Half:
       if (Target->hasFloat16Type() || !getLangOpts().OpenMP ||
           !getLangOpts().OpenMPIsDevice) {
         Width = Target->getHalfWidth();
         Align = Target->getHalfAlign();
       } else {
         assert(getLangOpts().OpenMP && getLangOpts().OpenMPIsDevice &&
static FloatingRank getFloatingRank(QualType T) {
   switch (T->castAs<BuiltinType>()->getKind()) {
   default: llvm_unreachable("getFloatingRank(): not a floating type");
   case BuiltinType::Float16:    return Float16Rank;
   case BuiltinType::Half:       return HalfRank;
   case BuiltinType::Float:      return FloatRank;
   case BuiltinType::Double:     return DoubleRank;
   case BuiltinType::LongDouble: return LongDoubleRank;
   case BuiltinType::Float128:   return Float128Rank;
+  case BuiltinType::Bfloat16:     return Bfloat16Rank;
   }
 }
 
 /// getFloatingTypeOfSizeWithinDomain - Returns a real floating
 /// point or a complex type (based on typeDomain/typeSize).
 /// 'typeDomain' is a real floating point or complex type.
 /// 'typeSize' is a real floating point or complex type.
 QualType ASTContext::getFloatingTypeOfSizeWithinDomain(QualType Size,
                                                        QualType Domain) const {
   FloatingRank EltRank = getFloatingRank(Size);
   if (Domain->isComplexType()) {
     switch (EltRank) {
+    case Bfloat16Rank:
     case Float16Rank:
     case HalfRank: llvm_unreachable("Complex half is not supported");
     case FloatRank:      return FloatComplexTy;
     case DoubleRank:     return DoubleComplexTy;
     case LongDoubleRank: return LongDoubleComplexTy;
     case Float128Rank:   return Float128ComplexTy;
     }
   }
 
   assert(Domain->isRealFloatingType() && "Unknown domain!");
   switch (EltRank) {
   case Float16Rank:    return HalfTy;
+  case Bfloat16Rank:   return Bfloat16Ty;
   case HalfRank:       return HalfTy;
   case FloatRank:      return FloatTy;
   case DoubleRank:     return DoubleTy;
   case LongDoubleRank: return LongDoubleTy;
   case Float128Rank:   return Float128Ty;
   }
   llvm_unreachable("getFloatingRank(): illegal value for rank");
 }
case BuiltinType::Long:
       return C->getTargetInfo().getLongWidth() == 32 ? 'l' : 'q';
     case BuiltinType::LongLong:   return 'q';
     case BuiltinType::Int128:     return 't';
     case BuiltinType::Float:      return 'f';
     case BuiltinType::Double:     return 'd';
     case BuiltinType::LongDouble: return 'D';
     case BuiltinType::NullPtr:    return '*'; // like char*
 
+    case BuiltinType::Bfloat16:
     case BuiltinType::Float16:
     case BuiltinType::Float128:
     case BuiltinType::Half:
     case BuiltinType::ShortAccum:
     case BuiltinType::Accum:
     case BuiltinType::LongAccum:
     case BuiltinType::UShortAccum:
     case BuiltinType::UAccum:
while (!Done) {
     }
   }
 
   QualType Type;
 
   // Read the base type.
   switch (*Str++) {
   default: llvm_unreachable("Unknown builtin type letter!");
+  case 'y':
+    assert(HowLong == 0 && !Signed && !Unsigned &&
+           "Bad modifiers used with 'y'!");
+    Type = Context.Bfloat16Ty;
+    break;
   case 'v':
     assert(HowLong == 0 && !Signed && !Unsigned &&
            "Bad modifiers used with 'v'!");
     Type = Context.VoidTy;
     break;
   case 'h':
     assert(HowLong == 0 && !Signed && !Unsigned &&
            "Bad modifiers used with 'h'!");

clang/lib/AST/ItaniumMangle.cpp

 //===--- ItaniumMangle.cpp - Itanium C++ Name Mangling ----------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
void CXXNameMangler::mangleType(const BuiltinType *T) {
   case BuiltinType::Float128: {
     const TargetInfo *TI = getASTContext().getLangOpts().OpenMP &&
                                    getASTContext().getLangOpts().OpenMPIsDevice
                                ? getASTContext().getAuxTargetInfo()
                                : &getASTContext().getTargetInfo();
     Out << TI->getFloat128Mangling();
     break;
   }
+  case BuiltinType::Bfloat16: {
+    const TargetInfo *TI = &getASTContext().getTargetInfo();
+    Out << TI->getBfloat16Mangling();
+    break;
+  }
   case BuiltinType::NullPtr:
     Out << "Dn";
     break;
 
 #define BUILTIN_TYPE(Id, SingletonId)
 #define PLACEHOLDER_TYPE(Id, SingletonId) \
   case BuiltinType::Id:
 #include "clang/AST/BuiltinTypes.def"
if (T->getVectorKind() == VectorType::NeonPolyVector) {
     case BuiltinType::UShort:    EltName = "uint16_t"; break;
     case BuiltinType::Int:       EltName = "int32_t"; break;
     case BuiltinType::UInt:      EltName = "uint32_t"; break;
     case BuiltinType::LongLong:  EltName = "int64_t"; break;
     case BuiltinType::ULongLong: EltName = "uint64_t"; break;
     case BuiltinType::Double:    EltName = "float64_t"; break;
     case BuiltinType::Float:     EltName = "float32_t"; break;
     case BuiltinType::Half:      EltName = "float16_t";break;
+    case BuiltinType::Bfloat16:  EltName = "bfloat16x1_t";break;
     default:
       llvm_unreachable("unexpected Neon vector element type");
     }
   }
   const char *BaseName = nullptr;
   unsigned BitSize = (T->getNumElements() *
                       getASTContext().getTypeSize(EltType));
   if (BitSize == 64)
static StringRef mangleAArch64VectorBase(const BuiltinType *EltType) {
   case BuiltinType::ULongLong:
     return "Uint64";
   case BuiltinType::Half:
     return "Float16";
   case BuiltinType::Float:
     return "Float32";
   case BuiltinType::Double:
     return "Float64";
+  case BuiltinType::Bfloat16:
+    return "Bfloat16";
   default:
     llvm_unreachable("Unexpected vector element base type");
   }
 }
 
 // AArch64's ABI for Neon vector types specifies that they should be mangled as
 // the equivalent internal name. The vector type must be one of the special
 // types predefined by ARM.

clang/lib/AST/MicrosoftMangle.cpp

 //===--- MicrosoftMangle.cpp - Microsoft Visual C++ Name Mangling ---------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
#include "clang/Basic/AArch64SVEACLETypes.def"
   case BuiltinType::SatUAccum:
   case BuiltinType::SatULongAccum:
   case BuiltinType::SatShortFract:
   case BuiltinType::SatFract:
   case BuiltinType::SatLongFract:
   case BuiltinType::SatUShortFract:
   case BuiltinType::SatUFract:
   case BuiltinType::SatULongFract:
+  case BuiltinType::Bfloat16:
   case BuiltinType::Float128: {
     DiagnosticsEngine &Diags = Context.getDiags();
     unsigned DiagID = Diags.getCustomDiagID(
         DiagnosticsEngine::Error, "cannot mangle this built-in %0 type yet");
     Diags.Report(Range.getBegin(), DiagID)
         << T->getName(Context.getASTContext().getPrintingPolicy()) << Range;
     break;
   }

clang/lib/AST/NSAPI.cpp

 //===--- NSAPI.cpp - NSFoundation APIs ------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
#include "clang/Basic/AArch64SVEACLETypes.def"
   case BuiltinType::UnknownAny:
   case BuiltinType::ARCUnbridgedCast:
   case BuiltinType::Half:
   case BuiltinType::PseudoObject:
   case BuiltinType::BuiltinFn:
   case BuiltinType::OMPArraySection:
   case BuiltinType::OMPArrayShaping:
   case BuiltinType::OMPIterator:
+  case BuiltinType::Bfloat16:
     break;
   }
 
   return None;
 }
 
 /// Returns true if \param T is a typedef of "BOOL" in objective-c.
 bool NSAPI::isObjCBOOLType(QualType T) const {

clang/lib/AST/PrintfFormatString.cpp

 //== PrintfFormatString.cpp - Analysis of printf format strings --*- C++ -*-==//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
bool PrintfSpecifier::fixType(QualType QT, const LangOptions &LangOpt,
   case BuiltinType::WChar_U:
   case BuiltinType::WChar_S:
   case BuiltinType::Char8: // FIXME: Treat like 'char'?
   case BuiltinType::Char16:
   case BuiltinType::Char32:
   case BuiltinType::UInt128:
   case BuiltinType::Int128:
   case BuiltinType::Half:
+  case BuiltinType::Bfloat16:
   case BuiltinType::Float16:
   case BuiltinType::Float128:
   case BuiltinType::ShortAccum:
   case BuiltinType::Accum:
   case BuiltinType::LongAccum:
   case BuiltinType::UShortAccum:
   case BuiltinType::UAccum:
   case BuiltinType::ULongAccum:

clang/lib/AST/Type.cpp

 //===- Type.cpp - Type representation and manipulation --------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
bool Type::isRealType() const {
   if (const auto *ET = dyn_cast<EnumType>(CanonicalType))
       return ET->getDecl()->isComplete() && !ET->getDecl()->isScoped();
   return false;
 }
 
 bool Type::isArithmeticType() const {
   if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
     return BT->getKind() >= BuiltinType::Bool &&
-           BT->getKind() <= BuiltinType::Float128;
+           BT->getKind() <= BuiltinType::Float128 &&
+           BT->getKind() != BuiltinType::Bfloat16;
   if (const auto *ET = dyn_cast<EnumType>(CanonicalType))
     // GCC allows forward declaration of enum types (forbid by C99 6.7.2.3p2).
     // If a body isn't seen by the time we get here, return false.
     //
     // C++0x: Enumerations are not arithmetic types. For now, just return
     // false for scoped enumerations since that will disable any
     // unwanted implicit conversions.
     return !ET->getDecl()->isScoped() && ET->getDecl()->isComplete();
StringRef BuiltinType::getName(const PrintingPolicy &Policy) const {
   case ULong:
     return "unsigned long";
   case ULongLong:
     return "unsigned long long";
   case UInt128:
     return "unsigned __int128";
   case Half:
     return Policy.Half ? "half" : "__fp16";
+  case Bfloat16:
+    return "__bf16";
   case Float:
     return "float";
   case Double:
     return "double";
   case LongDouble:
     return "long double";
   case ShortAccum:
     return "short _Accum";

clang/lib/AST/TypeLoc.cpp

 //===- TypeLoc.cpp - Type Source Info Wrapper -----------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
TypeSpecifierType BuiltinTypeLoc::getWrittenTypeSpec() const {
   case BuiltinType::SatUAccum:
   case BuiltinType::SatULongAccum:
   case BuiltinType::SatShortFract:
   case BuiltinType::SatFract:
   case BuiltinType::SatLongFract:
   case BuiltinType::SatUShortFract:
   case BuiltinType::SatUFract:
   case BuiltinType::SatULongFract:
+  case BuiltinType::Bfloat16:
     llvm_unreachable("Builtin type needs extra local data!");
     // Fall through, if the impossible happens.
 
   case BuiltinType::NullPtr:
   case BuiltinType::Overload:
   case BuiltinType::Dependent:
   case BuiltinType::BoundMember:
   case BuiltinType::UnknownAny:

clang/lib/Basic/TargetInfo.cpp

 //===--- TargetInfo.cpp - Information about Target machine ----------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
TargetInfo::TargetInfo(const llvm::Triple &T) : TargetOpts(), Triple(T) {
   // SPARC.  These should be overridden by concrete targets as needed.
   BigEndian = !T.isLittleEndian();
   TLSSupported = true;
   VLASupported = true;
   NoAsmVariants = false;
   HasLegalHalfType = false;
   HasFloat128 = false;
   HasFloat16 = false;
+  HasBfloat16 = false;
   PointerWidth = PointerAlign = 32;
   BoolWidth = BoolAlign = 8;
   IntWidth = IntAlign = 32;
   LongWidth = LongAlign = 32;
   LongLongWidth = LongLongAlign = 64;
 
   // Fixed point default bit widths
   ShortAccumWidth = ShortAccumAlign = 16;

clang/lib/Basic/Targets/AArch64.h

 //===--- AArch64.h - Declare AArch64 target feature support -----*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
public:
 
   StringRef getConstraintRegister(StringRef Constraint,
                                   StringRef Expression) const override {
     return Expression;
   }
 
   int getEHDataRegisterNumber(unsigned RegNo) const override;
 
+  const char *getBfloat16Mangling() const override { return "u6__bf16"; };
   bool hasInt128Type() const override;
 };
 
 class LLVM_LIBRARY_VISIBILITY AArch64leTargetInfo : public AArch64TargetInfo {
 public:
   AArch64leTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts);
 
   void getTargetDefines(const LangOptions &Opts,

clang/lib/Basic/Targets/AArch64.cpp

 //===--- AArch64.cpp - Implement AArch64 target feature support -----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
AArch64TargetInfo::AArch64TargetInfo(const llvm::Triple &Triple,
 
   MaxVectorAlign = 128;
   MaxAtomicInlineWidth = 128;
   MaxAtomicPromoteWidth = 128;
 
   LongDoubleWidth = LongDoubleAlign = SuitableAlign = 128;
   LongDoubleFormat = &llvm::APFloat::IEEEquad();
 
+  Bfloat16Width = Bfloat16Align = 16;
+  Bfloat16Format = &llvm::APFloat::Bfloat();
+
   // Make __builtin_ms_va_list available.
   HasBuiltinMSVaList = true;
 
   // Make the SVE types available.  Note that this deliberately doesn't
   // depend on SveMode, since in principle it should be possible to turn
   // SVE on and off within a translation unit.  It should also be possible
   // to compile the global declaration:
   //
bool AArch64TargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
   HasCRC = false;
   HasCrypto = false;
   HasUnaligned = true;
   HasFullFP16 = false;
   HasDotProd = false;
   HasFP16FML = false;
   HasMTE = false;
   HasTME = false;
+  HasBfloat16 = false;
   ArchKind = llvm::AArch64::ArchKind::ARMV8A;
 
   for (const auto &Feature : Features) {
     if (Feature == "+neon")
       FPU |= NeonMode;
     if (Feature == "+sve")
       FPU |= SveMode;
     if (Feature == "+crc")
for (const auto &Feature : Features) {
     if (Feature == "+dotprod")
       HasDotProd = true;
     if (Feature == "+fp16fml")
       HasFP16FML = true;
     if (Feature == "+mte")
       HasMTE = true;
     if (Feature == "+tme")
       HasTME = true;
+    if (Feature == "+bf16")
+      HasBfloat16 = true;
   }
 
   setDataLayout();
 
   return true;
 }
 
 TargetInfo::CallingConvCheckResult

clang/lib/Basic/Targets/ARM.h

 //===--- ARM.h - Declare ARM target feature support -------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
StringRef getConstraintRegister(StringRef Constraint,
     return Expression;
   }
 
   CallingConvCheckResult checkCallingConvention(CallingConv CC) const override;
 
   int getEHDataRegisterNumber(unsigned RegNo) const override;
 
   bool hasSjLjLowering() const override;
+
+  const char *getBfloat16Mangling() const override { return "u6__bf16"; };
 };
 
 class LLVM_LIBRARY_VISIBILITY ARMleTargetInfo : public ARMTargetInfo {
 public:
   ARMleTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts);
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override;
 };

clang/lib/Basic/Targets/ARM.cpp

 //===--- ARM.cpp - Implement ARM target feature support -------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //

 
 using namespace clang;
 using namespace clang::targets;
 
 void ARMTargetInfo::setABIAAPCS() {
   IsAAPCS = true;
 
   DoubleAlign = LongLongAlign = LongDoubleAlign = SuitableAlign = 64;
+  Bfloat16Width = Bfloat16Align = 16;
+  Bfloat16Format = &llvm::APFloat::Bfloat();
+
   const llvm::Triple &T = getTriple();
 
   bool IsNetBSD = T.isOSNetBSD();
   bool IsOpenBSD = T.isOSOpenBSD();
   if (!T.isOSWindows() && !IsNetBSD && !IsOpenBSD)
     WCharType = UnsignedInt;
 
   UseBitFieldTypeAlignment = true;
void ARMTargetInfo::setABIAPCS(bool IsAAPCS16) {
   const llvm::Triple &T = getTriple();
 
   IsAAPCS = false;
 
   if (IsAAPCS16)
     DoubleAlign = LongLongAlign = LongDoubleAlign = SuitableAlign = 64;
   else
     DoubleAlign = LongLongAlign = LongDoubleAlign = SuitableAlign = 32;
+  Bfloat16Width = Bfloat16Align = 16;
+  Bfloat16Format = &llvm::APFloat::Bfloat();
 
   WCharType = SignedInt;
 
   // Do not respect the alignment of bit-field types when laying out
   // structures. This corresponds to PCC_BITFIELD_TYPE_MATTERS in gcc.
   UseBitFieldTypeAlignment = false;
 
   /// gcc forces the alignment to 4 bytes, regardless of the type of the
bool ARMTargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
   DSP = 0;
   Unaligned = 1;
   SoftFloat = false;
   // Note that SoftFloatABI is initialized in our constructor.
   HWDiv = 0;
   DotProd = 0;
   HasFloat16 = true;
   ARMCDECoprocMask = 0;
+  HasBfloat16 = false;
 
   // This does not diagnose illegal cases like having both
   // "+vfpv2" and "+vfpv3" or having "+neon" and "-fp64".
   for (const auto &Feature : Features) {
     if (Feature == "+soft-float") {
       SoftFloat = true;
     } else if (Feature == "+vfp2sp" || Feature == "+vfp2") {
       FPU |= VFP2FPU;
if (Feature == "+soft-float") {
       HasLegalHalfType = true;
       FPU |= FPARMV8;
       MVE |= MVE_INT | MVE_FP;
       HW_FP |= HW_FP_SP | HW_FP_HP;
     } else if (Feature.size() == strlen("+cdecp0") && Feature >= "+cdecp0" &&
                Feature <= "+cdecp7") {
       unsigned Coproc = Feature.back() - '0';
       ARMCDECoprocMask |= (1U << Coproc);
+    } else if (Feature == "+bf16") {
+      HasBfloat16 = true;
     }
   }
 
   switch (ArchVersion) {
   case 6:
     if (ArchProfile == llvm::ARM::ProfileKind::M)
       LDREX = 0;
     else if (ArchKind == llvm::ARM::ArchKind::ARMV6K)

clang/lib/CodeGen/CGBuiltin.cpp

 //===---- CGBuiltin.cpp - Emit LLVM Code for builtins ---------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
static llvm::VectorType *GetNeonType(CodeGenFunction *CGF,
   int IsQuad = TypeFlags.isQuad();
   switch (TypeFlags.getEltType()) {
   case NeonTypeFlags::Int8:
   case NeonTypeFlags::Poly8:
     return llvm::VectorType::get(CGF->Int8Ty, V1Ty ? 1 : (8 << IsQuad));
   case NeonTypeFlags::Int16:
   case NeonTypeFlags::Poly16:
     return llvm::VectorType::get(CGF->Int16Ty, V1Ty ? 1 : (4 << IsQuad));
+  case NeonTypeFlags::Bfloat16:
+    if (HasLegalHalfType)
+      return llvm::VectorType::get(CGF->BfloatTy, V1Ty ? 1 : (4 << IsQuad));
+    else
+      return llvm::VectorType::get(CGF->Int16Ty, V1Ty ? 1 : (4 << IsQuad));
   case NeonTypeFlags::Float16:
     if (HasLegalHalfType)
       return llvm::VectorType::get(CGF->HalfTy, V1Ty ? 1 : (4 << IsQuad));
     else
       return llvm::VectorType::get(CGF->Int16Ty, V1Ty ? 1 : (4 << IsQuad));
   case NeonTypeFlags::Int32:
     return llvm::VectorType::get(CGF->Int32Ty, V1Ty ? 1 : (2 << IsQuad));
   case NeonTypeFlags::Int64:

clang/lib/CodeGen/CGDebugInfo.cpp

 //===--- CGDebugInfo.cpp - Emit Debug Information for a Module ------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
case BuiltinType::LongLong:
     break;
   case BuiltinType::Bool:
     Encoding = llvm::dwarf::DW_ATE_boolean;
     break;
   case BuiltinType::Half:
   case BuiltinType::Float:
   case BuiltinType::LongDouble:
   case BuiltinType::Float16:
+  case BuiltinType::Bfloat16:
   case BuiltinType::Float128:
   case BuiltinType::Double:
     // FIXME: For targets where long double and __float128 have the same size,
     // they are currently indistinguishable in the debugger without some
     // special treatment. However, there is currently no consensus on encoding
     // and this should be updated once a DWARF encoding exists for distinct
     // floating point types of the same size.
     Encoding = llvm::dwarf::DW_ATE_float;

clang/lib/CodeGen/CodeGenTypeCache.h

 //===--- CodeGenTypeCache.h - Commonly used LLVM types and info -*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //

 /// during IR emission.  It's initialized once in CodeGenModule's
 /// constructor and then copied around into new CodeGenFunctions.
 struct CodeGenTypeCache {
   /// void
   llvm::Type *VoidTy;
 
   /// i8, i16, i32, and i64
   llvm::IntegerType *Int8Ty, *Int16Ty, *Int32Ty, *Int64Ty;
-  /// float, double
-  llvm::Type *HalfTy, *FloatTy, *DoubleTy;
+  /// half, bfloat, float, double
+  llvm::Type *HalfTy, *BfloatTy, *FloatTy, *DoubleTy;
 
   /// int
   llvm::IntegerType *IntTy;
 
   /// intptr_t, size_t, and ptrdiff_t, which we assume are the same size.
   union {
     llvm::IntegerType *IntPtrTy;
     llvm::IntegerType *SizeTy;

clang/lib/CodeGen/CodeGenTypes.cpp

 //===--- CodeGenTypes.cpp - Type translation for LLVM CodeGen -------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
static llvm::Type *getTypeForFormat(llvm::LLVMContext &VMContext,
                                     const llvm::fltSemantics &format,
                                     bool UseNativeHalf = false) {
   if (&format == &llvm::APFloat::IEEEhalf()) {
     if (UseNativeHalf)
       return llvm::Type::getHalfTy(VMContext);
     else
       return llvm::Type::getInt16Ty(VMContext);
   }
+  if (&format == &llvm::APFloat::Bfloat()) {
+    if (UseNativeHalf)
+      return llvm::Type::getBfloatTy(VMContext);
+    else
+      return llvm::Type::getInt16Ty(VMContext);
+  }
   if (&format == &llvm::APFloat::IEEEsingle())
     return llvm::Type::getFloatTy(VMContext);
   if (&format == &llvm::APFloat::IEEEdouble())
     return llvm::Type::getDoubleTy(VMContext);
   if (&format == &llvm::APFloat::IEEEquad())
     return llvm::Type::getFP128Ty(VMContext);
   if (&format == &llvm::APFloat::PPCDoubleDouble())
     return llvm::Type::getPPC_FP128Ty(VMContext);
case BuiltinType::SatULongFract:
       break;
 
     case BuiltinType::Float16:
       ResultType =
           getTypeForFormat(getLLVMContext(), Context.getFloatTypeSemantics(T),
                            /* UseNativeHalf = */ true);
       break;
 
+    case BuiltinType::Bfloat16:
     case BuiltinType::Half:
       // Half FP can either be storage-only (lowered to i16) or native.
       ResultType = getTypeForFormat(
           getLLVMContext(), Context.getFloatTypeSemantics(T),
           Context.getLangOpts().NativeHalfType ||
               !Context.getTargetInfo().useFP16ConversionIntrinsics());
       break;
     case BuiltinType::Float:

clang/lib/CodeGen/ItaniumCXXABI.cpp

 //===------- ItaniumCXXABI.cpp - Emit LLVM Code from ASTs for a Module ----===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
#include "clang/Basic/AArch64SVEACLETypes.def"
     case BuiltinType::SatUAccum:
     case BuiltinType::SatULongAccum:
     case BuiltinType::SatShortFract:
     case BuiltinType::SatFract:
     case BuiltinType::SatLongFract:
     case BuiltinType::SatUShortFract:
     case BuiltinType::SatUFract:
     case BuiltinType::SatULongFract:
+    case BuiltinType::Bfloat16:
       return false;
 
     case BuiltinType::Dependent:
 #define BUILTIN_TYPE(Id, SingletonId)
 #define PLACEHOLDER_TYPE(Id, SingletonId) \
     case BuiltinType::Id:
 #include "clang/AST/BuiltinTypes.def"
       llvm_unreachable("asking for RRTI for a placeholder type!");

clang/lib/CodeGen/TargetInfo.cpp

 //===---- TargetInfo.cpp - Encapsulate target details -----------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
bool IsAAPCS_VFP =
       !isVariadic && isEffectivelyAAPCS_VFP(functionCallConv, /* AAPCS16 */ false);
 
   Ty = useFirstFieldIfTransparentUnion(Ty);
 
   // Handle illegal vector types here.
   if (isIllegalVectorType(Ty))
     return coerceIllegalVector(Ty);
 
-  // _Float16 and __fp16 get passed as if it were an int or float, but with
-  // the top 16 bits unspecified. This is not done for OpenCL as it handles the
-  // half type natively, and does not need to interwork with AAPCS code.
-  if ((Ty->isFloat16Type() || Ty->isHalfType()) &&
+  // _Float16, __fp16 and __bf16 get passed as if it were an int or float, but
+  // with the top 16 bits unspecified. This is not done for OpenCL as it handles
+  // the half type natively, and does not need to interwork with AAPCS code.
+  if ((Ty->isFloat16Type() || Ty->isHalfType() || Ty->isBFloat16Type()) &&
       !getContext().getLangOpts().NativeHalfArgsAndReturns) {
     llvm::Type *ResType = IsAAPCS_VFP ?
       llvm::Type::getFloatTy(getVMContext()) :
       llvm::Type::getInt32Ty(getVMContext());
     return ABIArgInfo::getDirect(ResType);
   }
 
   if (!isAggregateTypeForABI(Ty)) {
ABIArgInfo ARMABIInfo::classifyReturnType(QualType RetTy, bool isVariadic,
 
   if (const VectorType *VT = RetTy->getAs<VectorType>()) {
     // Large vector types should be returned via memory.
     if (getContext().getTypeSize(RetTy) > 128)
       return getNaturalAlignIndirect(RetTy);
     // FP16 vectors should be converted to integer vectors
     if (!getTarget().hasLegalHalfType() &&
         (VT->getElementType()->isFloat16Type() ||
+         VT->getElementType()->isBFloat16Type() ||
          VT->getElementType()->isHalfType()))
       return coerceIllegalVector(RetTy);
   }
 
   // _Float16 and __fp16 get returned as if it were an int or float, but with
   // the top 16 bits unspecified. This is not done for OpenCL as it handles the
   // half type natively, and does not need to interwork with AAPCS code.
-  if ((RetTy->isFloat16Type() || RetTy->isHalfType()) &&
+  if ((RetTy->isFloat16Type() || RetTy->isBFloat16Type() || RetTy->isHalfType()) &&
       !getContext().getLangOpts().NativeHalfArgsAndReturns) {
     llvm::Type *ResType = IsAAPCS_VFP ?
       llvm::Type::getFloatTy(getVMContext()) :
       llvm::Type::getInt32Ty(getVMContext());
     return ABIArgInfo::getDirect(ResType);
   }
 
   if (!isAggregateTypeForABI(RetTy)) {
ABIArgInfo ARMABIInfo::classifyReturnType(QualType RetTy, bool isVariadic,
   }
 
   return getNaturalAlignIndirect(RetTy);
 }
 
 /// isIllegalVector - check whether Ty is an illegal vector type.
 bool ARMABIInfo::isIllegalVectorType(QualType Ty) const {
   if (const VectorType *VT = Ty->getAs<VectorType> ()) {
-    // On targets that don't support FP16, FP16 is expanded into float, and we
-    // don't want the ABI to depend on whether or not FP16 is supported in
-    // hardware. Thus return false to coerce FP16 vectors into integer vectors.
+    // On targets that don't support half, fp16 or bfloat, they are expanded
+    // into float, and we don't want the ABI to depend on whether or not they
+    // are supported in hardware. Thus return false to coerce vectors of these
+    // types into integer vectors.
     if (!getTarget().hasLegalHalfType() &&
         (VT->getElementType()->isFloat16Type() ||
+         VT->getElementType()->isBFloat16Type() ||
          VT->getElementType()->isHalfType()))
       return true;
     if (isAndroid()) {
       // Android shipped using Clang 3.1, which supported a slightly different
       // vector ABI. The primary differences were that 3-element vector types
       // were legal, and so were sub 32-bit vectors (i.e. <2 x i8>). This path
       // accepts that legacy behavior for Android only.
       // Check whether VT is legal.
if (llvm::any_of(RD->fields(), [this](FieldDecl *FD) {
           return FD && containsAnyFP16Vectors(FD->getType());
         }))
       return true;
 
     return false;
   } else {
     if (const VectorType *VT = Ty->getAs<VectorType>())
       return (VT->getElementType()->isFloat16Type() ||
+              VT->getElementType()->isBFloat16Type() ||
               VT->getElementType()->isHalfType());
     return false;
   }
 }
 
 bool ARMABIInfo::isLegalVectorTypeForSwift(CharUnits vectorSize,
                                            llvm::Type *eltTy,
                                            unsigned numElts) const {

clang/lib/Format/FormatToken.cpp

 //===--- FormatToken.cpp - Format C++ code --------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 ///
bool FormatToken::isSimpleTypeSpecifier() const {
   case tok::kw_signed:
   case tok::kw_unsigned:
   case tok::kw_void:
   case tok::kw_char:
   case tok::kw_int:
   case tok::kw_half:
   case tok::kw_float:
   case tok::kw_double:
+  case tok::kw___bf16:
   case tok::kw__Float16:
   case tok::kw___float128:
   case tok::kw_wchar_t:
   case tok::kw_bool:
   case tok::kw___underlying_type:
   case tok::annot_typename:
   case tok::kw_char8_t:
   case tok::kw_char16_t:

clang/lib/Index/USRGeneration.cpp

 //===- USRGeneration.cpp - Routines for USR generation --------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
#include "clang/Basic/AArch64SVEACLETypes.def"
         case BuiltinType::SatUAccum:
         case BuiltinType::SatULongAccum:
         case BuiltinType::SatShortFract:
         case BuiltinType::SatFract:
         case BuiltinType::SatLongFract:
         case BuiltinType::SatUShortFract:
         case BuiltinType::SatUFract:
         case BuiltinType::SatULongFract:
+        case BuiltinType::Bfloat16:
           IgnoreResults = true;
           return;
         case BuiltinType::ObjCId:
           c = 'o'; break;
         case BuiltinType::ObjCClass:
           c = 'O'; break;
         case BuiltinType::ObjCSel:
           c = 'e'; break;

clang/lib/Parse/ParseDecl.cpp

 //===--- ParseDecl.cpp - Declaration Parsing --------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
while (1) {
     case tok::kw___int128:
       isInvalid = DS.SetTypeSpecType(DeclSpec::TST_int128, Loc, PrevSpec,
                                      DiagID, Policy);
       break;
     case tok::kw_half:
       isInvalid = DS.SetTypeSpecType(DeclSpec::TST_half, Loc, PrevSpec,
                                      DiagID, Policy);
       break;
+    case tok::kw___bf16:
+      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_Bfloat16, Loc, PrevSpec,
+                                     DiagID, Policy);
+      break;
     case tok::kw_float:
       isInvalid = DS.SetTypeSpecType(DeclSpec::TST_float, Loc, PrevSpec,
                                      DiagID, Policy);
       break;
     case tok::kw_double:
       isInvalid = DS.SetTypeSpecType(DeclSpec::TST_double, Loc, PrevSpec,
                                      DiagID, Policy);
       break;
bool Parser::isKnownToBeTypeSpecifier(const Token &Tok) const {
   case tok::kw__Imaginary:
   case tok::kw_void:
   case tok::kw_char:
   case tok::kw_wchar_t:
   case tok::kw_char8_t:
   case tok::kw_char16_t:
   case tok::kw_char32_t:
   case tok::kw_int:
+  case tok::kw___bf16:
   case tok::kw_half:
   case tok::kw_float:
   case tok::kw_double:
   case tok::kw__Accum:
   case tok::kw__Fract:
   case tok::kw__Float16:
   case tok::kw___float128:
   case tok::kw_bool:
bool Parser::isTypeSpecifierQualifier() {
   case tok::kw_void:
   case tok::kw_char:
   case tok::kw_wchar_t:
   case tok::kw_char8_t:
   case tok::kw_char16_t:
   case tok::kw_char32_t:
   case tok::kw_int:
   case tok::kw_half:
+  case tok::kw___bf16:
   case tok::kw_float:
   case tok::kw_double:
   case tok::kw__Accum:
   case tok::kw__Fract:
   case tok::kw__Float16:
   case tok::kw___float128:
   case tok::kw_bool:
   case tok::kw__Bool:
bool Parser::isDeclarationSpecifier(bool DisambiguatingWithExpression) {
   case tok::kw_char:
   case tok::kw_wchar_t:
   case tok::kw_char8_t:
   case tok::kw_char16_t:
   case tok::kw_char32_t:
 
   case tok::kw_int:
   case tok::kw_half:
+  case tok::kw___bf16:
   case tok::kw_float:
   case tok::kw_double:
   case tok::kw__Accum:
   case tok::kw__Fract:
   case tok::kw__Float16:
   case tok::kw___float128:
   case tok::kw_bool:
   case tok::kw__Bool:

clang/lib/Parse/ParseExpr.cpp

 //===--- ParseExpr.cpp - Expression Parsing -------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 ///
#undef RTT_JOIN
   case tok::kw_long:
   case tok::kw___int64:
   case tok::kw___int128:
   case tok::kw_signed:
   case tok::kw_unsigned:
   case tok::kw_half:
   case tok::kw_float:
   case tok::kw_double:
+  case tok::kw___bf16:
   case tok::kw__Float16:
   case tok::kw___float128:
   case tok::kw_void:
   case tok::kw_typename:
   case tok::kw_typeof:
   case tok::kw___vector:
 #define GENERIC_IMAGE_TYPE(ImgType, Id) case tok::kw_##ImgType##_t:
 #include "clang/Basic/OpenCLImageTypes.def"

clang/lib/Parse/ParseExprCXX.cpp

 //===--- ParseExprCXX.cpp - C++ Expression Parsing ------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
case tok::kw_char:
     DS.SetTypeSpecType(DeclSpec::TST_char, Loc, PrevSpec, DiagID, Policy);
     break;
   case tok::kw_int:
     DS.SetTypeSpecType(DeclSpec::TST_int, Loc, PrevSpec, DiagID, Policy);
     break;
   case tok::kw___int128:
     DS.SetTypeSpecType(DeclSpec::TST_int128, Loc, PrevSpec, DiagID, Policy);
     break;
+  case tok::kw___bf16:
+    DS.SetTypeSpecType(DeclSpec::TST_Bfloat16, Loc, PrevSpec, DiagID, Policy);
+    break;
   case tok::kw_half:
     DS.SetTypeSpecType(DeclSpec::TST_half, Loc, PrevSpec, DiagID, Policy);
     break;
   case tok::kw_float:
     DS.SetTypeSpecType(DeclSpec::TST_float, Loc, PrevSpec, DiagID, Policy);
     break;
   case tok::kw_double:
     DS.SetTypeSpecType(DeclSpec::TST_double, Loc, PrevSpec, DiagID, Policy);

clang/lib/Parse/ParseTentative.cpp

 //===--- ParseTentative.cpp - Ambiguity Resolution Parsing ----------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
#define TYPE_TRAIT(N,Spelling,K) \
   case tok::kw_##Spelling:
 #include "clang/Basic/TokenKinds.def"
     return TPResult::True;
 
   // Obviously starts a type-specifier-seq:
   case tok::kw_char:
   case tok::kw_const:
   case tok::kw_double:
+  case tok::kw___bf16:
   case tok::kw__Float16:
   case tok::kw___float128:
   case tok::kw_enum:
   case tok::kw_half:
   case tok::kw_float:
   case tok::kw_int:
   case tok::kw_long:
   case tok::kw___int64:
Parser::isCXXDeclarationSpecifier(Parser::TPResult BracedCastResult,
   case tok::kw_long:
   case tok::kw___int64:
   case tok::kw___int128:
   case tok::kw_signed:
   case tok::kw_unsigned:
   case tok::kw_half:
   case tok::kw_float:
   case tok::kw_double:
+  case tok::kw___bf16:
   case tok::kw__Float16:
   case tok::kw___float128:
   case tok::kw_void:
   case tok::annot_decltype:
 #define GENERIC_IMAGE_TYPE(ImgType, Id) case tok::kw_##ImgType##_t:
 #include "clang/Basic/OpenCLImageTypes.def"
     if (NextToken().is(tok::l_paren))
       return TPResult::Ambiguous;
bool Parser::isCXXDeclarationSpecifierAType() {
   case tok::kw_long:
   case tok::kw___int64:
   case tok::kw___int128:
   case tok::kw_signed:
   case tok::kw_unsigned:
   case tok::kw_half:
   case tok::kw_float:
   case tok::kw_double:
+  case tok::kw___bf16:
   case tok::kw__Float16:
   case tok::kw___float128:
   case tok::kw_void:
   case tok::kw___unknown_anytype:
   case tok::kw___auto_type:
 #define GENERIC_IMAGE_TYPE(ImgType, Id) case tok::kw_##ImgType##_t:
 #include "clang/Basic/OpenCLImageTypes.def"
     return true;

clang/lib/Sema/DeclSpec.cpp

 //===--- DeclSpec.cpp - Declaration Specifier Semantic Analysis -----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
switch (DS.getTypeSpecType()) {
     case TST_int128:
     case TST_struct:
     case TST_interface:
     case TST_union:
     case TST_unknown_anytype:
     case TST_unspecified:
     case TST_void:
     case TST_wchar:
+    case TST_Bfloat16:
 #define GENERIC_IMAGE_TYPE(ImgType, Id) case TST_##ImgType##_t:
 #include "clang/Basic/OpenCLImageTypes.def"
       return false;
 
     case TST_decltype_auto:
       // This must have an initializer, so can't be a function declaration,
       // even if the initializer has function type.
       return false;
const char *DeclSpec::getSpecifierName(DeclSpec::TST T,
   case DeclSpec::TST_typeofExpr:  return "typeof";
   case DeclSpec::TST_auto:        return "auto";
   case DeclSpec::TST_auto_type:   return "__auto_type";
   case DeclSpec::TST_decltype:    return "(decltype)";
   case DeclSpec::TST_decltype_auto: return "decltype(auto)";
   case DeclSpec::TST_underlyingType: return "__underlying_type";
   case DeclSpec::TST_unknown_anytype: return "__unknown_anytype";
   case DeclSpec::TST_atomic: return "_Atomic";
+  case DeclSpec::TST_Bfloat16: return "__bf16";
 #define GENERIC_IMAGE_TYPE(ImgType, Id) \
   case DeclSpec::TST_##ImgType##_t: \
     return #ImgType "_t";
 #include "clang/Basic/OpenCLImageTypes.def"
   case DeclSpec::TST_error:       return "(error)";
   }
   llvm_unreachable("Unknown typespec!");
 }

clang/lib/Sema/SemaChecking.cpp

 //===- SemaChecking.cpp - Extra Semantic Checking -------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
case NeonTypeFlags::Float16:
     assert(!shift && "cannot shift float types!");
     return (4 << IsQuad) - 1;
   case NeonTypeFlags::Float32:
     assert(!shift && "cannot shift float types!");
     return (2 << IsQuad) - 1;
   case NeonTypeFlags::Float64:
     assert(!shift && "cannot shift float types!");
     return (1 << IsQuad) - 1;
+  case NeonTypeFlags::Bfloat16:
+    assert(!shift && "cannot shift float types!");
+    return (4 << IsQuad) - 1;
   }
   llvm_unreachable("Invalid NeonTypeFlag!");
 }
 
 /// getNeonEltType - Return the QualType corresponding to the elements of
 /// the vector type specified by the NeonTypeFlags.  This is used to check
 /// the pointer arguments for Neon load/store intrinsics.
 static QualType getNeonEltType(NeonTypeFlags Flags, ASTContext &Context,
static QualType getNeonEltType(NeonTypeFlags Flags, ASTContext &Context,
   case NeonTypeFlags::Poly128:
     break;
   case NeonTypeFlags::Float16:
     return Context.HalfTy;
   case NeonTypeFlags::Float32:
     return Context.FloatTy;
   case NeonTypeFlags::Float64:
     return Context.DoubleTy;
+  case NeonTypeFlags::Bfloat16:
+    return Context.Bfloat16Ty;
   }
   llvm_unreachable("Invalid NeonTypeFlag!");
 }
 
 bool Sema::CheckSVEBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
   // Range check SVE intrinsics that take immediate values.
   SmallVector<std::tuple<int,int,int>, 3> ImmChecks;
 

clang/lib/Sema/SemaDecl.cpp

 //===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
bool Sema::isSimpleTypeSpecifier(tok::TokenKind Kind) const {
   case tok::kw_signed:
   case tok::kw_unsigned:
   case tok::kw_void:
   case tok::kw_char:
   case tok::kw_int:
   case tok::kw_half:
   case tok::kw_float:
   case tok::kw_double:
+  case tok::kw___bf16:
   case tok::kw__Float16:
   case tok::kw___float128:
   case tok::kw_wchar_t:
   case tok::kw_bool:
   case tok::kw___underlying_type:
   case tok::kw___auto_type:
     return true;
 

clang/lib/Sema/SemaOverload.cpp

 //===--- SemaOverload.cpp - C++ Overloading -------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
FromType = ToType.getUnqualifiedType();
              (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
     // Complex-real conversions (C99 6.3.1.7)
     SCS.Second = ICK_Complex_Real;
     FromType = ToType.getUnqualifiedType();
   } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
     // FIXME: disable conversions between long double and __float128 if
     // their representation is different until there is back end support
     // We of course allow this conversion if long double is really double.
+    if (FromType == S.Context.Bfloat16Ty || ToType == S.Context.Bfloat16Ty)
+      return false;
     if (&S.Context.getFloatTypeSemantics(FromType) !=
         &S.Context.getFloatTypeSemantics(ToType)) {
       bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
                                     ToType == S.Context.LongDoubleTy) ||
                                    (FromType == S.Context.LongDoubleTy &&
                                     ToType == S.Context.Float128Ty));
       if (Float128AndLongDouble &&
           (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) ==

clang/lib/Sema/SemaTemplateVariadic.cpp

 //===------- SemaTemplateVariadic.cpp - C++ Variadic Templates ------------===/
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //===----------------------------------------------------------------------===/
 //
 //  This file implements semantic analysis for C++0x variadic templates.
bool Sema::containsUnexpandedParameterPacks(Declarator &D) {
   case TST_enum:
   case TST_union:
   case TST_struct:
   case TST_interface:
   case TST_class:
   case TST_auto:
   case TST_auto_type:
   case TST_decltype_auto:
+  case TST_Bfloat16:
 #define GENERIC_IMAGE_TYPE(ImgType, Id) case TST_##ImgType##_t:
 #include "clang/Basic/OpenCLImageTypes.def"
   case TST_unknown_anytype:
   case TST_error:
     break;
   }
 
   for (unsigned I = 0, N = D.getNumTypeObjects(); I != N; ++I) {

clang/lib/Sema/SemaType.cpp

 //===--- SemaType.cpp - Semantic Analysis for Types -----------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
case DeclSpec::TST_float16:
     // ToDo: more precise diagnostics for CUDA.
     if (!S.Context.getTargetInfo().hasFloat16Type() && !S.getLangOpts().CUDA &&
         !(S.getLangOpts().OpenMP && S.getLangOpts().OpenMPIsDevice))
       S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_unsupported)
         << "_Float16";
     Result = Context.Float16Ty;
     break;
   case DeclSpec::TST_half:    Result = Context.HalfTy; break;
+  case DeclSpec::TST_Bfloat16:
+    if (!S.Context.getTargetInfo().hasBfloat16Type())
+      S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_unsupported)
+        << "__bf16";
+    Result = Context.Bfloat16Ty;
+    break;
   case DeclSpec::TST_float:   Result = Context.FloatTy; break;
   case DeclSpec::TST_double:
     if (DS.getTypeSpecWidth() == DeclSpec::TSW_long)
       Result = Context.LongDoubleTy;
     else
       Result = Context.DoubleTy;
     break;
   case DeclSpec::TST_float128:
return BTy->getKind() == BuiltinType::SChar ||
          BTy->getKind() == BuiltinType::UShort ||
          BTy->getKind() == BuiltinType::Int ||
          BTy->getKind() == BuiltinType::UInt ||
          BTy->getKind() == BuiltinType::Long ||
          BTy->getKind() == BuiltinType::ULong ||
          BTy->getKind() == BuiltinType::LongLong ||
          BTy->getKind() == BuiltinType::ULongLong ||
          BTy->getKind() == BuiltinType::Float ||
-         BTy->getKind() == BuiltinType::Half;
+         BTy->getKind() == BuiltinType::Half ||
+         BTy->getKind() == BuiltinType::Bfloat16;
 }
 
 /// HandleNeonVectorTypeAttr - The "neon_vector_type" and
 /// "neon_polyvector_type" attributes are used to create vector types that
 /// are mangled according to ARM's ABI.  Otherwise, these types are identical
 /// to those created with the "vector_size" attribute.  Unlike "vector_size"
 /// the argument to these Neon attributes is the number of vector elements,
 /// not the vector size in bytes.  The vector width and element type must

clang/lib/Serialization/ASTCommon.cpp

 //===--- ASTCommon.cpp - Common stuff for ASTReader/ASTWriter----*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
case BuiltinType::OMPArraySection:
     ID = PREDEF_TYPE_OMP_ARRAY_SECTION;
     break;
   case BuiltinType::OMPArrayShaping:
     ID = PREDEF_TYPE_OMP_ARRAY_SHAPING;
     break;
   case BuiltinType::OMPIterator:
     ID = PREDEF_TYPE_OMP_ITERATOR;
     break;
+  case BuiltinType::Bfloat16:
+    ID = PREDEF_TYPE_BFLOAT16_ID;
+    break;
   }
 
   return TypeIdx(ID);
 }
 
 unsigned serialization::ComputeHash(Selector Sel) {
   unsigned N = Sel.getNumArgs();
   if (N == 0)

clang/lib/Serialization/ASTReader.cpp

 //===- ASTReader.cpp - AST File Reader ------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
case PREDEF_TYPE_LONG_ID:
       T = Context.LongTy;
       break;
     case PREDEF_TYPE_LONGLONG_ID:
       T = Context.LongLongTy;
       break;
     case PREDEF_TYPE_INT128_ID:
       T = Context.Int128Ty;
       break;
+    case PREDEF_TYPE_BFLOAT16_ID:
+      T = Context.Bfloat16Ty;
+      break;
     case PREDEF_TYPE_HALF_ID:
       T = Context.HalfTy;
       break;
     case PREDEF_TYPE_FLOAT_ID:
       T = Context.FloatTy;
       break;
     case PREDEF_TYPE_DOUBLE_ID:
       T = Context.DoubleTy;

clang/test/CodeGen/arm-mangle-16bit-float.cpp

+// RUN: %clang_cc1 -triple aarch64-arm-none-eabi -fallow-half-arguments-and-returns -target-feature +bf16 -target-feature +fullfp16 -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK64
+// RUN: %clang_cc1 -triple arm-arm-none-eabi     -fallow-half-arguments-and-returns -target-feature +bf16 -target-feature +fullfp16 -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK32
+
+// CHECK64: define {{.*}}void @_Z3foou6__bf16(bfloat %b)
+// CHECK32: define {{.*}}void @_Z3foou6__bf16(i32 %b.coerce)
+void foo(__bf16 b) {}
+
+// CHECK64: define {{.*}}void @_Z3barDh(half %b)
+// CHECK32: define {{.*}}void @_Z3barDh(i32 %b.coerce)
+void bar(__fp16 b) {}

clang/test/Sema/arm-bfloat.cpp

+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 \
+// RUN: -triple aarch64-arm-none-eabi -target-cpu cortex-a75 \
+// RUN: -target-feature +bf16 -target-feature +neon %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 \
+// RUN: -triple arm-arm-none-eabi -target-cpu cortex-a53 \
+// RUN: -target-feature +bf16 -target-feature +neon %s
+
+void test(bool b) {
+  __bf16 bf16;
+
+  bf16 + bf16; // expected-error {{invalid operands to binary expression ('__bf16' and '__bf16')}}
+  bf16 - bf16; // expected-error {{invalid operands to binary expression ('__bf16' and '__bf16')}}
+  bf16 * bf16; // expected-error {{invalid operands to binary expression ('__bf16' and '__bf16')}}
+  bf16 / bf16; // expected-error {{invalid operands to binary expression ('__bf16' and '__bf16')}}
+
+  __fp16 fp16;
+
+  bf16 + fp16; // expected-error {{invalid operands to binary expression ('__bf16' and '__fp16')}}
+  fp16 + bf16; // expected-error {{invalid operands to binary expression ('__fp16' and '__bf16')}}
+  bf16 - fp16; // expected-error {{invalid operands to binary expression ('__bf16' and '__fp16')}}
+  fp16 - bf16; // expected-error {{invalid operands to binary expression ('__fp16' and '__bf16')}}
+  bf16 * fp16; // expected-error {{invalid operands to binary expression ('__bf16' and '__fp16')}}
+  fp16 * bf16; // expected-error {{invalid operands to binary expression ('__fp16' and '__bf16')}}
+  bf16 / fp16; // expected-error {{invalid operands to binary expression ('__bf16' and '__fp16')}}
+  fp16 / bf16; // expected-error {{invalid operands to binary expression ('__fp16' and '__bf16')}}
+  bf16 = fp16; // expected-error {{assigning to '__bf16' from incompatible type '__fp16'}}
+  fp16 = bf16; // expected-error {{assigning to '__fp16' from incompatible type '__bf16'}}
+  bf16 + (b ? fp16 : bf16); // expected-error {{incompatible operand types ('__fp16' and '__bf16')}}
+}

clang/tools/libclang/CXType.cpp

 //===- CXType.cpp - Implements 'CXTypes' aspect of libclang ---------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===--------------------------------------------------------------------===//
 //
switch (K) {
     TKIND(DependentSizedArray);
     TKIND(Vector);
     TKIND(ExtVector);
     TKIND(MemberPointer);
     TKIND(Auto);
     TKIND(Elaborated);
     TKIND(Pipe);
     TKIND(Attributed);
+    TKIND(Bfloat16);
 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) TKIND(Id);
 #include "clang/Basic/OpenCLImageTypes.def"
 #undef IMAGE_TYPE
 #define EXT_OPAQUE_TYPE(ExtTYpe, Id, Ext) TKIND(Id);
 #include "clang/Basic/OpenCLExtensionTypes.def"
     TKIND(OCLSampler);
     TKIND(OCLEvent);
     TKIND(OCLQueue);