Index: clang-tools-extra/clang-tidy/modernize/LoopConvertCheck.cpp
===================================================================
--- clang-tools-extra/clang-tidy/modernize/LoopConvertCheck.cpp
+++ clang-tools-extra/clang-tidy/modernize/LoopConvertCheck.cpp
@@ -402,7 +402,8 @@
     if ((Cast->getCastKind() == CK_NoOp &&
          Context->hasSameType(Cast->getType(), E->getType().withConst())) ||
         (Cast->getCastKind() == CK_LValueToRValue &&
-         !Cast->getType().isNull() && Cast->getType()->isFundamentalType()))
+         !Cast->getType().isNull() &&
+         Cast->getType()->isFundamentalType(*Context)))
       return false;
   }
   // FIXME: Make this function more generic.
@@ -624,7 +625,8 @@
   SourceRange ParenRange(Loop->getLParenLoc(), Loop->getRParenLoc());
 
   QualType Type = Context->getAutoDeductType();
-  if (!Descriptor.ElemType.isNull() && Descriptor.ElemType->isFundamentalType())
+  if (!Descriptor.ElemType.isNull() &&
+      Descriptor.ElemType->isFundamentalType(*Context))
     Type = Descriptor.ElemType.getUnqualifiedType();
   Type = Type.getDesugaredType(*Context);
 
Index: clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp
===================================================================
--- clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp
+++ clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp
@@ -410,7 +410,7 @@
     return true;
 
   // Arithmetic types are interconvertible, except scoped enums.
-  if (ParamType->isArithmeticType() && ArgType->isArithmeticType()) {
+  if (ParamType->isArithmeticType(Ctx) && ArgType->isArithmeticType(Ctx)) {
     if ((ParamType->isEnumeralType() &&
          ParamType->castAs<EnumType>()->getDecl()->isScoped()) ||
         (ArgType->isEnumeralType() &&
Index: clang/docs/LanguageExtensions.rst
===================================================================
--- clang/docs/LanguageExtensions.rst
+++ clang/docs/LanguageExtensions.rst
@@ -799,7 +799,9 @@
 
 ``_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:
+``__bf16`` is an arithmetic type on targets with native bfloat16 arithmetic support, 
+and a storage-only type on targets that lack such support but can store bfloat16,
+such as:
 
 * 32-bit ARM
 * 64-bit ARM (AArch64)
Index: clang/include/clang/AST/ASTContext.h
===================================================================
--- clang/include/clang/AST/ASTContext.h
+++ clang/include/clang/AST/ASTContext.h
@@ -58,6 +58,16 @@
 
 namespace clang {
 
+// Conversion ranks introduced in C++23 6.8.6p2 [conv.rank]
+enum FloatingRankCompareResult {
+  FRCR_Unordered,
+  FRCR_Lesser,
+  FRCR_Greater,
+  FRCR_Equal,
+  FRCR_Equal_Lesser_Subrank,
+  FRCR_Equal_Greater_Subrank,
+};
+
 class APValue;
 class ASTMutationListener;
 class ASTRecordLayout;
@@ -1099,7 +1109,7 @@
   CanQualType SatUnsignedShortFractTy, SatUnsignedFractTy,
       SatUnsignedLongFractTy;
   CanQualType HalfTy; // [OpenCL 6.1.1.1], ARM NEON
-  CanQualType BFloat16Ty;
+  CanQualType BFloat16Ty; // [C++23 6.8.3p5], ISO/IEC/IEEE 60559.
   CanQualType Float16Ty; // C11 extension ISO/IEC TS 18661-3
   CanQualType VoidPtrTy, NullPtrTy;
   CanQualType DependentTy, OverloadTy, BoundMemberTy, UnknownAnyTy;
@@ -2789,14 +2799,21 @@
   /// Compare the rank of the two specified floating point types,
   /// ignoring the domain of the type (i.e. 'double' == '_Complex double').
   ///
-  /// If \p LHS > \p RHS, returns 1.  If \p LHS == \p RHS, returns 0.  If
-  /// \p LHS < \p RHS, return -1.
-  int getFloatingTypeOrder(QualType LHS, QualType RHS) const;
+  /// If \p LHS > \p RHS, returns FRCR_Greater. If \p LHS == \p RHS, returns
+  /// FRCR_Equal.  If \p LHS < \p RHS, return FRCR_Lesser. If \p LHS and \p RHS
+  /// are unordered, return FRCR_Unordered. If \p LHS and \p RHS are equal but
+  /// the subrank of \p LHS is greater than \p RHS, return
+  /// FRCR_Equal_Greater_Subrank. If \p LHS and \p RHS are equal but the subrank
+  /// of \p LHS is less than \p RHS, return FRCR_Equal_Lesser_Subrank. Subrank
+  /// and Unordered comparison were introduced in C++23.
+  FloatingRankCompareResult getFloatingTypeOrder(QualType LHS,
+                                                 QualType RHS) const;
 
   /// Compare the rank of two floating point types as above, but compare equal
   /// if both types have the same floating-point semantics on the target (i.e.
-  /// long double and double on AArch64 will return 0).
-  int getFloatingTypeSemanticOrder(QualType LHS, QualType RHS) const;
+  /// long double and double on AArch64 will return FRCR_Equal).
+  FloatingRankCompareResult getFloatingTypeSemanticOrder(QualType LHS,
+                                                         QualType RHS) const;
 
   unsigned getTargetAddressSpace(LangAS AS) const;
 
Index: clang/include/clang/AST/Type.h
===================================================================
--- clang/include/clang/AST/Type.h
+++ clang/include/clang/AST/Type.h
@@ -2149,17 +2149,30 @@
   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)
+  /// C++23 6.8.2p12 [basic.fundamental] (standard floating point + extended
+  /// floating point)
+  bool isCXX23FloatingPointType(const ASTContext &Ctx) const;
+  /// C++23 6.8.2p12 [basic.fundamental] (standard floating point)
+  bool isCXX23StandardFloatingPointType(const ASTContext &Ctx) const;
+  /// C++23 6.8.2p12 [basic.fundamental] (extended floating point)
+  bool isCXX23ExtendedFloatingPointType(const ASTContext &Ctx) const;
+  /// C++23 6.8.2p12 [basic.fundamental] (Used to determine if at least one
+  /// of the types is a standard floating-point type and the other is an
+  /// extended floating-point type)
+  bool isCXX23StandardAndExtendedFpOp(const ASTContext &Ctx,
+                                      QualType &Type) const;
   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;
   bool isFloat128Type() const;
   bool isIbm128Type() const;
   bool isRealType() const;         // C99 6.2.5p17 (real floating + integer)
-  bool isArithmeticType() const;   // C99 6.2.5p18 (integer + floating)
+  bool isArithmeticType(
+      const ASTContext &Ctx) 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 isFundamentalType(const ASTContext &Ctx) const;
   bool isCompoundType() const;
 
   // Type Predicates: Check to see if this type is structurally the specified
@@ -6886,12 +6899,11 @@
 /// Tests whether the type is categorized as a fundamental type.
 ///
 /// \returns True for types specified in C++0x [basic.fundamental].
-inline bool Type::isFundamentalType() const {
-  return isVoidType() ||
-         isNullPtrType() ||
+inline bool Type::isFundamentalType(const ASTContext &Ctx) const {
+  return isVoidType() || isNullPtrType() ||
          // FIXME: It's really annoying that we don't have an
          // 'isArithmeticType()' which agrees with the standard definition.
-         (isArithmeticType() && !isEnumeralType());
+         (isArithmeticType(Ctx) && !isEnumeralType());
 }
 
 /// Tests whether the type is categorized as a compound type.
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -8750,6 +8750,7 @@
 >;
 def err_cast_to_bfloat16 : Error<"cannot type-cast to __bf16">;
 def err_cast_from_bfloat16 : Error<"cannot type-cast from __bf16">;
+def err_cxx23_invalid_implicit_floating_point_cast : Error<"floating point cast results in loss of precision">;
 def err_typecheck_expect_scalar_operand : Error<
   "operand of type %0 where arithmetic or pointer type is required">;
 def err_typecheck_cond_incompatible_operands : Error<
Index: clang/include/clang/Basic/TargetInfo.h
===================================================================
--- clang/include/clang/Basic/TargetInfo.h
+++ clang/include/clang/Basic/TargetInfo.h
@@ -219,6 +219,7 @@
   bool HasFloat128;
   bool HasFloat16;
   bool HasBFloat16;
+  bool HasFullBFloat16;
   bool HasIbm128;
   bool HasLongDouble;
   bool HasFPReturn;
@@ -650,6 +651,10 @@
   /// Determine whether the _BFloat16 type is supported on this target.
   virtual bool hasBFloat16Type() const { return HasBFloat16; }
 
+  /// Determine whether the BFloat type is fully supported on this target, i.e
+  /// arithemtic operations.
+  virtual bool hasFullBFloat16Type() const { return HasFullBFloat16; }
+
   /// Determine whether the __ibm128 type is supported on this target.
   virtual bool hasIbm128Type() const { return HasIbm128; }
 
Index: clang/include/clang/Lex/LiteralSupport.h
===================================================================
--- clang/include/clang/Lex/LiteralSupport.h
+++ clang/include/clang/Lex/LiteralSupport.h
@@ -72,6 +72,7 @@
   bool isFract : 1;         // 1.0hr/r/lr/uhr/ur/ulr
   bool isAccum : 1;         // 1.0hk/k/lk/uhk/uk/ulk
   bool isBitInt : 1;        // 1wb, 1uwb (C2x)
+  bool isBFloat16 : 1;      // 1.0bf
   uint8_t MicrosoftInteger; // Microsoft suffix extension i8, i16, i32, or i64.
 
 
Index: clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConv.h
===================================================================
--- clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConv.h
+++ clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConv.h
@@ -13,6 +13,7 @@
 #ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SMTCONV_H
 #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_SMTCONV_H
 
+#include "clang/AST/ASTContext.h"
 #include "clang/AST/Expr.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/APSIntType.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
@@ -601,7 +602,7 @@
     // Perform type conversion
     if ((LTy->isIntegralOrEnumerationType() &&
          RTy->isIntegralOrEnumerationType()) &&
-        (LTy->isArithmeticType() && RTy->isArithmeticType())) {
+        (LTy->isArithmeticType(Ctx) && RTy->isArithmeticType(Ctx))) {
       SMTConv::doIntTypeConversion<llvm::SMTExprRef, &fromCast>(
           Solver, Ctx, LHS, LTy, RHS, RTy);
       return;
@@ -775,11 +776,11 @@
     // If we have two real floating types, convert the smaller operand to the
     // bigger result
     // Note: Safe to skip updating bitwidth because this must terminate
-    int order = Ctx.getFloatingTypeOrder(LTy, RTy);
-    if (order > 0) {
+    FloatingRankCompareResult order = Ctx.getFloatingTypeOrder(LTy, RTy);
+    if ((order == FRCR_Greater) || (order == FRCR_Equal_Greater_Subrank)) {
       RHS = (*doCast)(Solver, RHS, LTy, LBitWidth, RTy, RBitWidth);
       RTy = LTy;
-    } else if (order == 0) {
+    } else if ((order == FRCR_Equal) || (order == FRCR_Equal_Lesser_Subrank)) {
       LHS = (*doCast)(Solver, LHS, RTy, RBitWidth, LTy, LBitWidth);
       LTy = RTy;
     } else {
Index: clang/lib/AST/ASTContext.cpp
===================================================================
--- clang/lib/AST/ASTContext.cpp
+++ clang/lib/AST/ASTContext.cpp
@@ -112,6 +112,83 @@
   Ibm128Rank
 };
 
+constexpr unsigned CXX23FloatRankToIndex(clang::BuiltinType::Kind Kind) {
+  switch (Kind) {
+  case clang::BuiltinType::Float16:
+    return 0;
+  case clang::BuiltinType::BFloat16:
+    return 1;
+  case clang::BuiltinType::Float:
+    return 2;
+  case clang::BuiltinType::Double:
+    return 3;
+  case clang::BuiltinType::LongDouble:
+    return 4;
+  default:
+    llvm_unreachable("Not a CXX23+ floating point builtin type");
+  }
+}
+
+// C++23 6.8.6p2 [conv.rank]
+// Grid to determine the rank of a floating point type when compared with
+// another floating point type.
+constexpr std::array<std::array<FloatingRankCompareResult, 5>, 5>
+    CXX23FloatingPointConversionRankMap = {
+        {// Float16 x Float16
+         // Float16 x BFloat16
+         // Float16 x Float
+         // Float16 x Double
+         // Float16 x LongDouble
+         {{FloatingRankCompareResult::FRCR_Equal,
+           FloatingRankCompareResult::FRCR_Unordered,
+           FloatingRankCompareResult::FRCR_Lesser,
+           FloatingRankCompareResult::FRCR_Lesser,
+           FloatingRankCompareResult::FRCR_Lesser}},
+
+         // BFloat16 x Float16
+         // BFloat16 x BFloat16
+         // BFloat16 x Float
+         // BFloat16 x Double
+         // BFloat16 x LongDouble
+         {{FloatingRankCompareResult::FRCR_Unordered,
+           FloatingRankCompareResult::FRCR_Equal,
+           FloatingRankCompareResult::FRCR_Lesser,
+           FloatingRankCompareResult::FRCR_Lesser,
+           FloatingRankCompareResult::FRCR_Lesser}},
+
+         // Float x Float16
+         // Float x BFloat16
+         // Float x Float
+         // Float x Double
+         // Float x LongDouble
+         {{FloatingRankCompareResult::FRCR_Greater,
+           FloatingRankCompareResult::FRCR_Greater,
+           FloatingRankCompareResult::FRCR_Equal,
+           FloatingRankCompareResult::FRCR_Lesser,
+           FloatingRankCompareResult::FRCR_Lesser}},
+
+         // Double x Float16
+         // Double x BFloat16
+         // Double x Float
+         // Double x Double
+         // Double x LongDouble
+         {{FloatingRankCompareResult::FRCR_Greater,
+           FloatingRankCompareResult::FRCR_Greater,
+           FloatingRankCompareResult::FRCR_Greater,
+           FloatingRankCompareResult::FRCR_Equal,
+           FloatingRankCompareResult::FRCR_Lesser}},
+
+         // LongDouble x Float16
+         // LongDouble x BFloat16
+         // LongDouble x Float
+         // LongDouble x Double
+         // LongDouble x LongDouble
+         {{FloatingRankCompareResult::FRCR_Greater,
+           FloatingRankCompareResult::FRCR_Greater,
+           FloatingRankCompareResult::FRCR_Greater,
+           FloatingRankCompareResult::FRCR_Greater,
+           FloatingRankCompareResult::FRCR_Equal}}}};
+
 /// \returns location that is relevant when searching for Doc comments related
 /// to \p D.
 static SourceLocation getDeclLocForCommentSearch(const Decl *D,
@@ -2136,7 +2213,7 @@
       Align = Target->getLongFractAlign();
       break;
     case BuiltinType::BFloat16:
-      if (Target->hasBFloat16Type()) {
+      if (Target->hasBFloat16Type() || Target->hasFullBFloat16Type()) {
         Width = Target->getBFloat16Width();
         Align = Target->getBFloat16Align();
       } else if ((getLangOpts().SYCLIsDevice ||
@@ -7077,24 +7154,47 @@
   }
 }
 
+/// C++23 6.8.5 [conv.rank]
 /// getFloatingTypeOrder - Compare the rank of the two specified floating
 /// point types, ignoring the domain of the type (i.e. 'double' ==
-/// '_Complex double').  If LHS > RHS, return 1.  If LHS == RHS, return 0. If
-/// LHS < RHS, return -1.
-int ASTContext::getFloatingTypeOrder(QualType LHS, QualType RHS) const {
+/// '_Complex double').
+/// If LHS > RHS, return FRCR_Greater.  If LHS == RHS, return FRCR_Equal. If
+/// LHS < RHS, return FRCR_Lesser. If the values representedable by the two
+/// are not subset of each other, return FRCR_Unordered. If LHS == RHS but
+/// LHS has a higher subrank than RHS return FRCR_Equal_Greater_Subrank else
+/// return FRCR_Equal_Lesser_Subrank.
+FloatingRankCompareResult ASTContext::getFloatingTypeOrder(QualType LHS,
+                                                           QualType RHS) const {
+  if (LHS->isCXX23FloatingPointType(*this) &&
+      RHS->isCXX23FloatingPointType(*this)) {
+    BuiltinType::Kind LHSKind;
+    BuiltinType::Kind RHSKind;
+    if (const auto *CT = LHS->getAs<ComplexType>())
+      LHSKind = CT->getElementType()->castAs<BuiltinType>()->getKind();
+    else
+      LHSKind = LHS->castAs<BuiltinType>()->getKind();
+    if (const auto *CT = RHS->getAs<ComplexType>())
+      RHSKind = CT->getElementType()->castAs<BuiltinType>()->getKind();
+    else
+      RHSKind = RHS->castAs<BuiltinType>()->getKind();
+    return CXX23FloatingPointConversionRankMap[CXX23FloatRankToIndex(LHSKind)]
+                                              [CXX23FloatRankToIndex(RHSKind)];
+  }
+
   FloatingRank LHSR = getFloatingRank(LHS);
   FloatingRank RHSR = getFloatingRank(RHS);
 
   if (LHSR == RHSR)
-    return 0;
+    return FRCR_Equal;
   if (LHSR > RHSR)
-    return 1;
-  return -1;
+    return FRCR_Greater;
+  return FRCR_Lesser;
 }
 
-int ASTContext::getFloatingTypeSemanticOrder(QualType LHS, QualType RHS) const {
+FloatingRankCompareResult
+ASTContext::getFloatingTypeSemanticOrder(QualType LHS, QualType RHS) const {
   if (&getFloatTypeSemantics(LHS) == &getFloatTypeSemantics(RHS))
-    return 0;
+    return FRCR_Equal;
   return getFloatingTypeOrder(LHS, RHS);
 }
 
Index: clang/lib/AST/Interp/ByteCodeExprGen.cpp
===================================================================
--- clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -1109,7 +1109,7 @@
   if (!DiscardResult && AK == DerefKind::Read) {
     if (VD->hasLocalStorage() && VD->hasInit() && !VD->isConstexpr()) {
       QualType VT = VD->getType();
-      if (VT.isConstQualified() && VT->isFundamentalType())
+      if (VT.isConstQualified() && VT->isFundamentalType(VD->getASTContext()))
         return this->visit(VD->getInit());
     }
   }
Index: clang/lib/AST/StmtPrinter.cpp
===================================================================
--- clang/lib/AST/StmtPrinter.cpp
+++ clang/lib/AST/StmtPrinter.cpp
@@ -1348,6 +1348,7 @@
   case BuiltinType::Float:      OS << 'F'; break;
   case BuiltinType::LongDouble: OS << 'L'; break;
   case BuiltinType::Float128:   OS << 'Q'; break;
+  case BuiltinType::BFloat16:   OS << "BF16"; break;
   }
 }
 
Index: clang/lib/AST/Type.cpp
===================================================================
--- clang/lib/AST/Type.cpp
+++ clang/lib/AST/Type.cpp
@@ -2157,6 +2157,42 @@
   return false;
 }
 
+bool Type::isCXX23StandardFloatingPointType(const ASTContext &Ctx) const {
+  if (!Ctx.getLangOpts().CPlusPlus23)
+    return false;
+  if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
+    return BT->getKind() >= BuiltinType::Float &&
+           BT->getKind() <= BuiltinType::LongDouble;
+  if (const auto *CT = dyn_cast<ComplexType>(CanonicalType))
+    return CT->getElementType()->isCXX23StandardFloatingPointType(Ctx);
+  return false;
+}
+
+bool Type::isCXX23ExtendedFloatingPointType(const ASTContext &Ctx) const {
+  if (!Ctx.getLangOpts().CPlusPlus23)
+    return false;
+  if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
+    return BT->getKind() == BuiltinType::Float16 ||
+           (Ctx.getTargetInfo().hasFullBFloat16Type() &&
+            (BT->getKind() == BuiltinType::BFloat16));
+  if (const auto *CT = dyn_cast<ComplexType>(CanonicalType))
+    return CT->getElementType()->isCXX23ExtendedFloatingPointType(Ctx);
+  return false;
+}
+
+bool Type::isCXX23FloatingPointType(const ASTContext &Ctx) const {
+  return isCXX23StandardFloatingPointType(Ctx) ||
+         isCXX23ExtendedFloatingPointType(Ctx);
+}
+
+bool Type::isCXX23StandardAndExtendedFpOp(const ASTContext &Ctx,
+                                          QualType &Type) const {
+  return (((isCXX23FloatingPointType(Ctx) &&
+            Type->isCXX23FloatingPointType(Ctx))) &&
+          (isCXX23ExtendedFloatingPointType(Ctx) ||
+           Type->isCXX23ExtendedFloatingPointType(Ctx)));
+}
+
 bool Type::hasFloatingRepresentation() const {
   if (const auto *VT = dyn_cast<VectorType>(CanonicalType))
     return VT->getElementType()->isFloatingType();
@@ -2180,11 +2216,12 @@
   return isBitIntType();
 }
 
-bool Type::isArithmeticType() const {
+bool Type::isArithmeticType(const ASTContext &Ctx) const {
   if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
-    return BT->getKind() >= BuiltinType::Bool &&
-           BT->getKind() <= BuiltinType::Ibm128 &&
-           BT->getKind() != BuiltinType::BFloat16;
+      return (BT->getKind() >= BuiltinType::Bool &&
+              BT->getKind() <= BuiltinType::Ibm128 &&
+              (BT->getKind() != BuiltinType::BFloat16 ||
+               Ctx.getTargetInfo().hasFullBFloat16Type()));
   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.
Index: clang/lib/Basic/TargetInfo.cpp
===================================================================
--- clang/lib/Basic/TargetInfo.cpp
+++ clang/lib/Basic/TargetInfo.cpp
@@ -64,6 +64,7 @@
   HasIbm128 = false;
   HasFloat16 = false;
   HasBFloat16 = false;
+  HasFullBFloat16 = false;
   HasLongDouble = true;
   HasFPReturn = true;
   HasStrictFP = false;
Index: clang/lib/Basic/Targets/AMDGPU.h
===================================================================
--- clang/lib/Basic/Targets/AMDGPU.h
+++ clang/lib/Basic/Targets/AMDGPU.h
@@ -118,7 +118,7 @@
   }
 
   bool hasBFloat16Type() const override { return isAMDGCN(getTriple()); }
-  const char *getBFloat16Mangling() const override { return "u6__bf16"; };
+  const char *getBFloat16Mangling() const override { return "DF16b"; };
 
   std::string_view getClobbers() const override { return ""; }
 
Index: clang/lib/Basic/Targets/ARM.cpp
===================================================================
--- clang/lib/Basic/Targets/ARM.cpp
+++ clang/lib/Basic/Targets/ARM.cpp
@@ -514,6 +514,7 @@
   HasFloat16 = true;
   ARMCDECoprocMask = 0;
   HasBFloat16 = false;
+  HasFullBFloat16 = false;
   FPRegsDisabled = false;
 
   // This does not diagnose illegal cases like having both
Index: clang/lib/Basic/Targets/NVPTX.h
===================================================================
--- clang/lib/Basic/Targets/NVPTX.h
+++ clang/lib/Basic/Targets/NVPTX.h
@@ -181,7 +181,7 @@
 
   bool hasBitIntType() const override { return true; }
   bool hasBFloat16Type() const override { return true; }
-  const char *getBFloat16Mangling() const override { return "u6__bf16"; };
+  const char *getBFloat16Mangling() const override { return "DF16b"; };
 };
 } // namespace targets
 } // namespace clang
Index: clang/lib/Basic/Targets/X86.h
===================================================================
--- clang/lib/Basic/Targets/X86.h
+++ clang/lib/Basic/Targets/X86.h
@@ -417,7 +417,7 @@
     return getPointerWidthV(AddrSpace);
   }
 
-  const char *getBFloat16Mangling() const override { return "u6__bf16"; };
+  const char *getBFloat16Mangling() const override { return "DF16b"; };
 };
 
 // X86-32 generic target
Index: clang/lib/Basic/Targets/X86.cpp
===================================================================
--- clang/lib/Basic/Targets/X86.cpp
+++ clang/lib/Basic/Targets/X86.cpp
@@ -359,6 +359,8 @@
       HasCRC32 = true;
     } else if (Feature == "+x87") {
       HasX87 = true;
+    } else if (Feature == "+fullbf16") {
+      HasFullBFloat16 = true;
     }
 
     X86SSEEnum Level = llvm::StringSwitch<X86SSEEnum>(Feature)
@@ -1117,6 +1119,7 @@
       .Case("xsavec", HasXSAVEC)
       .Case("xsaves", HasXSAVES)
       .Case("xsaveopt", HasXSAVEOPT)
+      .Case("fullbf16", HasFullBFloat16)
       .Default(false);
 }
 
Index: clang/lib/CodeGen/CGExpr.cpp
===================================================================
--- clang/lib/CodeGen/CGExpr.cpp
+++ clang/lib/CodeGen/CGExpr.cpp
@@ -3000,7 +3000,7 @@
     // __imag can only produce an rvalue on scalars.
     if (E->getOpcode() == UO_Real &&
         !LV.getAddress(*this).getElementType()->isStructTy()) {
-      assert(E->getSubExpr()->getType()->isArithmeticType());
+      assert(E->getSubExpr()->getType()->isArithmeticType(getContext()));
       return LV;
     }
 
Index: clang/lib/CodeGen/CGExprScalar.cpp
===================================================================
--- clang/lib/CodeGen/CGExprScalar.cpp
+++ clang/lib/CodeGen/CGExprScalar.cpp
@@ -3446,7 +3446,8 @@
     assert(
         isa<ConstantMatrixType>(BO->getLHS()->getType().getCanonicalType()) &&
         "first operand must be a matrix");
-    assert(BO->getRHS()->getType().getCanonicalType()->isArithmeticType() &&
+    assert(BO->getRHS()->getType().getCanonicalType()->isArithmeticType(
+               CGF.getContext()) &&
            "second operand must be an arithmetic type");
     CodeGenFunction::CGFPOptionsRAII FPOptsRAII(CGF, Ops.FPFeatures);
     return MB.CreateScalarDiv(Ops.LHS, Ops.RHS,
Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -5568,7 +5568,7 @@
                       QualType Ty) const override;
 
   bool allowBFloatArgsAndRet() const override {
-    return getTarget().hasBFloat16Type();
+    return getTarget().hasBFloat16Type() || getTarget().hasFullBFloat16Type();
   }
 };
 
@@ -6365,7 +6365,8 @@
   ABIKind getABIKind() const { return Kind; }
 
   bool allowBFloatArgsAndRet() const override {
-    return !IsFloatABISoftFP && getTarget().hasBFloat16Type();
+    return !IsFloatABISoftFP &&
+           (getTarget().hasBFloat16Type() || getTarget().hasFullBFloat16Type());
   }
 
 private:
Index: clang/lib/Frontend/InitPreprocessor.cpp
===================================================================
--- clang/lib/Frontend/InitPreprocessor.cpp
+++ clang/lib/Frontend/InitPreprocessor.cpp
@@ -454,8 +454,13 @@
     if (LangOpts.CPlusPlus26)
       // FIXME: Use correct value for C++26.
       Builder.defineMacro("__cplusplus", "202400L");
-    else if (LangOpts.CPlusPlus23)
+    else if (LangOpts.CPlusPlus23) {
       Builder.defineMacro("__cplusplus", "202302L");
+      // [C++23] 15.11p2 [cpp.predefined]
+      Builder.defineMacro("__STDCPP_FLOAT16_T__", "1");
+      if (TI.hasFullBFloat16Type())
+        Builder.defineMacro("__STDCPP_BFLOAT16_T__", "1");
+    }
     //      [C++20] The integer literal 202002L.
     else if (LangOpts.CPlusPlus20)
       Builder.defineMacro("__cplusplus", "202002L");
Index: clang/lib/Lex/LiteralSupport.cpp
===================================================================
--- clang/lib/Lex/LiteralSupport.cpp
+++ clang/lib/Lex/LiteralSupport.cpp
@@ -858,6 +858,7 @@
   isAccum = false;
   hadError = false;
   isBitInt = false;
+  isBFloat16 = false;
 
   // This routine assumes that the range begin/end matches the regex for integer
   // and FP constants (specifically, the 'pp-number' regex), and assumes that
@@ -958,6 +959,23 @@
 
       isFloat = true;
       continue;  // Success.
+    // C++23 5.13.4 [lex.fcon]
+    case 'b':
+    case 'B':
+      if (!isFPConstant)
+        break; // Error for integer constant.
+      if (s + 3 < ThisTokEnd && (s[1] == 'f' || s[1] == 'F') && s[2] == '1' &&
+          s[3] == '6') {
+        if (!LangOpts.CPlusPlus23 || !Target.hasFullBFloat16Type())
+          break;
+        if (HasSize)
+          break;
+        HasSize = true;
+        s += 3;
+        isBFloat16 = true;
+        continue;
+      }
+      break;
     case 'q':    // FP Suffix for "__float128"
     case 'Q':
       if (!isFPConstant) break;  // Error for integer constant.
@@ -1090,6 +1108,7 @@
         saw_fixed_point_suffix = false;
         isFract = false;
         isAccum = false;
+        isBFloat16 = false;
       }
 
       saw_ud_suffix = true;
Index: clang/lib/Sema/Sema.cpp
===================================================================
--- clang/lib/Sema/Sema.cpp
+++ clang/lib/Sema/Sema.cpp
@@ -694,6 +694,23 @@
     }
   }
 
+  // C++23 7.3.10 [conv.double]
+  // A prvalue of floating-point type can be converted to a prvalue of another
+  // floating-point type with a greater or equal conversion rank ([conv.rank]).
+  // A prvalue of standard floating-point type can be converted to a prvalue of
+  // another standard floating-point type
+  if (ExprTy->isCXX23StandardAndExtendedFpOp(Context, TypeTy) &&
+      Kind == CK_FloatingCast && E->isPRValue() &&
+      (CCK == CCK_ImplicitConversion)) {
+    auto conversionRank = Context.getFloatingTypeOrder(TypeTy, ExprTy);
+    if (conversionRank < FRCR_Greater) {
+      Diag(E->getExprLoc(),
+           diag::err_cxx23_invalid_implicit_floating_point_cast)
+          << E->getSourceRange();
+      return ExprError();
+    }
+  }
+
   if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(E)) {
     if (ImpCast->getCastKind() == Kind && (!BasePath || BasePath->empty())) {
       ImpCast->setType(Ty);
@@ -1975,7 +1992,9 @@
         (Ty->isIbm128Type() && !Context.getTargetInfo().hasIbm128Type()) ||
         (Ty->isIntegerType() && Context.getTypeSize(Ty) == 128 &&
          !Context.getTargetInfo().hasInt128Type()) ||
-        (Ty->isBFloat16Type() && !Context.getTargetInfo().hasBFloat16Type() &&
+        (Ty->isBFloat16Type() &&
+         !(Context.getTargetInfo().hasBFloat16Type() ||
+           Context.getTargetInfo().hasFullBFloat16Type()) &&
          !LangOpts.CUDAIsDevice) ||
         LongDoubleMismatched) {
       PartialDiagnostic PD = PDiag(diag::err_target_unsupported_type);
Index: clang/lib/Sema/SemaCast.cpp
===================================================================
--- clang/lib/Sema/SemaCast.cpp
+++ clang/lib/Sema/SemaCast.cpp
@@ -1359,6 +1359,19 @@
     }
   }
 
+  // [expr.static.cast] 7.6.1.9p11, A prvalue of floating-point type can
+  // be explicitly converted to any other floating-point type.
+  // Conversion between fp16 and bf16 is not supported yet.
+  if (SrcExpr.get()->isPRValue() &&
+      DestType->isCXX23StandardAndExtendedFpOp(Self.Context, SrcType)) {
+    // Support for cast between fp16 and bf16 doesn't exist yet.
+    if (!((DestType->isBFloat16Type() || DestType->isFloat16Type()) &&
+          (SrcType->isBFloat16Type() || SrcType->isFloat16Type()))) {
+      Kind = CK_FloatingCast;
+      return TC_Success;
+    }
+  }
+
   // Reverse integral promotion/conversion. All such conversions are themselves
   // again integral promotions or conversions and are thus already handled by
   // p2 (TryDirectInitialization above).
@@ -3108,8 +3121,9 @@
 
   // If either type is a pointer, the other type has to be either an
   // integer or a pointer.
-  if (!DestType->isArithmeticType()) {
-    if (!SrcType->isIntegralType(Self.Context) && SrcType->isArithmeticType()) {
+  if (!DestType->isArithmeticType(Self.Context)) {
+    if (!SrcType->isIntegralType(Self.Context) &&
+        SrcType->isArithmeticType(Self.Context)) {
       Self.Diag(SrcExpr.get()->getExprLoc(),
                 diag::err_cast_pointer_from_non_pointer_int)
         << SrcType << SrcExpr.get()->getSourceRange();
@@ -3118,9 +3132,9 @@
     }
     checkIntToPointerCast(/* CStyle */ true, OpRange, SrcExpr.get(), DestType,
                           Self);
-  } else if (!SrcType->isArithmeticType()) {
+  } else if (!SrcType->isArithmeticType(Self.Context)) {
     if (!DestType->isIntegralType(Self.Context) &&
-        DestType->isArithmeticType()) {
+        DestType->isArithmeticType(Self.Context)) {
       Self.Diag(SrcExpr.get()->getBeginLoc(),
                 diag::err_cast_pointer_to_non_pointer_int)
           << DestType << SrcExpr.get()->getSourceRange();
Index: clang/lib/Sema/SemaChecking.cpp
===================================================================
--- clang/lib/Sema/SemaChecking.cpp
+++ clang/lib/Sema/SemaChecking.cpp
@@ -10403,7 +10403,7 @@
     To = VecTy->getElementType();
   // It's a floating promotion if the source type is a lower rank.
   return ICE->getCastKind() == CK_FloatingCast &&
-         S.Context.getFloatingTypeOrder(From, To) < 0;
+         S.Context.getFloatingTypeOrder(From, To) == FRCR_Lesser;
 }
 
 bool
@@ -13693,9 +13693,12 @@
     return;
 
   // If both source and target are floating points, warn about losing precision.
-  int Order = S.getASTContext().getFloatingTypeSemanticOrder(
-      QualType(ResultBT, 0), QualType(RBT, 0));
-  if (Order < 0 && !S.SourceMgr.isInSystemMacro(E->getOperatorLoc()))
+  FloatingRankCompareResult Order =
+      S.getASTContext().getFloatingTypeSemanticOrder(QualType(ResultBT, 0),
+                                                     QualType(RBT, 0));
+
+  assert(Order != FRCR_Unordered && "Invalid floating point types");
+  if (Order == FRCR_Lesser && !S.SourceMgr.isInSystemMacro(E->getOperatorLoc()))
     // warn about dropping FP rank.
     DiagnoseImpCast(S, E->getRHS(), E->getLHS()->getType(), E->getOperatorLoc(),
                     diag::warn_impcast_float_result_precision);
@@ -14121,7 +14124,7 @@
 
       int Order = S.getASTContext().getFloatingTypeSemanticOrder(
           QualType(SourceBT, 0), QualType(TargetBT, 0));
-      if (Order > 0) {
+      if (Order == FRCR_Greater) {
         // Don't warn about float constants that are precisely
         // representable in the target type.
         Expr::EvalResult result;
@@ -14139,7 +14142,7 @@
         DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_precision);
       }
       // ... or possibly if we're increasing rank, too
-      else if (Order < 0) {
+      else if (Order == FRCR_Lesser) {
         if (S.SourceMgr.isInSystemMacro(CC))
           return;
 
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -793,7 +793,7 @@
       llvm_unreachable("Float evaluation method should be set by now");
       break;
     case LangOptions::FEM_Double:
-      if (Context.getFloatingTypeOrder(Context.DoubleTy, Ty) > 0)
+      if (Context.getFloatingTypeOrder(Context.DoubleTy, Ty) == FRCR_Greater)
         // Widen the expression to double.
         return Ty->isComplexType()
                    ? ImpCastExprToType(E,
@@ -802,7 +802,8 @@
                    : ImpCastExprToType(E, Context.DoubleTy, CK_FloatingCast);
       break;
     case LangOptions::FEM_Extended:
-      if (Context.getFloatingTypeOrder(Context.LongDoubleTy, Ty) > 0)
+      if (Context.getFloatingTypeOrder(Context.LongDoubleTy, Ty) ==
+          FRCR_Greater)
         // Widen the expression to long double.
         return Ty->isComplexType()
                    ? ImpCastExprToType(
@@ -1153,14 +1154,16 @@
     return RHSType;
 
   // Compute the rank of the two types, regardless of whether they are complex.
-  int Order = S.Context.getFloatingTypeOrder(LHSType, RHSType);
-  if (Order < 0)
+  FloatingRankCompareResult Order =
+      S.Context.getFloatingTypeOrder(LHSType, RHSType);
+  if (Order == FRCR_Lesser)
     // Promote the precision of the LHS if not an assignment.
     return handleComplexFloatConversion(S, LHS, LHSType, RHSType,
                                         /*PromotePrecision=*/!IsCompAssign);
   // Promote the precision of the RHS unless it is already the same as the LHS.
   return handleComplexFloatConversion(S, RHS, RHSType, LHSType,
-                                      /*PromotePrecision=*/Order > 0);
+                                      /*PromotePrecision=*/Order ==
+                                          clang::FRCR_Greater);
 }
 
 /// Handle arithmetic conversion from integer to float.  Helper function
@@ -1213,16 +1216,34 @@
     return LHSFloat ? LHSType : RHSType;
   }
 
-  // If we have two real floating types, convert the smaller operand
-  // to the bigger result.
+  // C++23 [expr.arith.conv] 7.4
+  // If the floating-point conversion ranks ([conv.rank]) of the types
+  // of the operands are ordered but not equal, then the operand of the type
+  // with the lesser floating-point conversion rank is converted to the type of
+  // the other operand.
+  //
+  // If the floating-point conversion ranks of the types of the operands are
+  // equal, then the operand with the lesser floating-point conversion subrank
+  // ([conv.rank]) is converted to the type of the other operand.
+  //
+  // Otherwise, the expression is ill-formed i.e unordered conversion rank
+  // between floating-point types.
   if (LHSFloat && RHSFloat) {
-    int order = S.Context.getFloatingTypeOrder(LHSType, RHSType);
-    if (order > 0) {
+    FloatingRankCompareResult order =
+        S.Context.getFloatingTypeOrder(LHSType, RHSType);
+
+    if (order == FRCR_Unordered) {
+      return QualType();
+    }
+
+    if (order == FRCR_Greater || order == FRCR_Equal_Greater_Subrank) {
       RHS = S.ImpCastExprToType(RHS.get(), LHSType, CK_FloatingCast);
       return LHSType;
     }
 
-    assert(order < 0 && "illegal float comparison");
+    assert(((order != FRCR_Equal) &&
+            (order == FRCR_Lesser || order == FRCR_Equal_Lesser_Subrank)) &&
+           "illegal float comparison");
     if (!IsCompAssign)
       LHS = S.ImpCastExprToType(LHS.get(), RHSType, CK_FloatingCast);
     return RHSType;
@@ -1559,7 +1580,8 @@
 
   // If either side is a non-arithmetic type (e.g. a pointer), we are done.
   // The caller can deal with this (e.g. pointer + int).
-  if (!LHSType->isArithmeticType() || !RHSType->isArithmeticType())
+  if (!LHSType->isArithmeticType(Context) ||
+      !RHSType->isArithmeticType(Context))
     return QualType();
 
   // Apply unary and bitfield promotions to the LHS's type.
@@ -3933,6 +3955,8 @@
       Ty = Context.Float16Ty;
     else if (Literal.isFloat128)
       Ty = Context.Float128Ty;
+    else if (Literal.isBFloat16)
+      Ty = Context.BFloat16Ty;
     else
       Ty = Context.DoubleTy;
 
@@ -4180,7 +4204,8 @@
   // scalar or vector data type argument..."
   // Every built-in scalar type (OpenCL 1.1 6.1.1) is either an arithmetic
   // type (C99 6.2.5p18) or void.
-  if (!(T->isArithmeticType() || T->isVoidType() || T->isVectorType())) {
+  if (!(T->isArithmeticType(S.Context) || T->isVoidType() ||
+        T->isVectorType())) {
     S.Diag(Loc, diag::err_vecstep_non_scalar_vector_type)
       << T << ArgRange;
     return true;
@@ -4725,7 +4750,7 @@
     return CT->getElementType();
 
   // Otherwise they pass through real integer and floating point types here.
-  if (V.get()->getType()->isArithmeticType())
+  if (V.get()->getType()->isArithmeticType(S.Context))
     return V.get()->getType();
 
   // Test for placeholders.
@@ -8972,7 +8997,7 @@
 
   // If both operands have arithmetic type, do the usual arithmetic conversions
   // to find a common type: C99 6.5.15p3,5.
-  if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) {
+  if (LHSTy->isArithmeticType(Context) && RHSTy->isArithmeticType(Context)) {
     // Disallow invalid arithmetic conversions, such as those between bit-
     // precise integers types of different sizes, or between a bit-precise
     // integer and another type.
@@ -9873,7 +9898,7 @@
   if (LHSType->isExtVectorType()) {
     if (RHSType->isExtVectorType())
       return Incompatible;
-    if (RHSType->isArithmeticType()) {
+    if (RHSType->isArithmeticType(Context)) {
       // CK_VectorSplat does T -> vector T, so first cast to the element type.
       if (ConvertRHS)
         RHS = prepareVectorSplat(LHSType, RHS.get());
@@ -9964,7 +9989,8 @@
     return Incompatible;
 
   // Arithmetic conversions.
-  if (LHSType->isArithmeticType() && RHSType->isArithmeticType() &&
+  if (LHSType->isArithmeticType(Context) &&
+      RHSType->isArithmeticType(Context) &&
       !(getLangOpts().CPlusPlus && LHSType->isEnumeralType())) {
     if (ConvertRHS)
       Kind = PrepareScalarCast(RHS, LHSType);
@@ -10539,7 +10565,8 @@
   } else if (vectorEltTy->isRealFloatingType()) {
     if (scalarTy->isRealFloatingType()) {
       if (S.getLangOpts().OpenCL &&
-          S.Context.getFloatingTypeOrder(vectorEltTy, scalarTy) < 0) {
+          S.Context.getFloatingTypeOrder(vectorEltTy, scalarTy) ==
+              clang::FRCR_Lesser) {
         DiagID = diag::err_opencl_scalar_type_rank_greater_than_vector_type;
         return true;
       }
@@ -10686,7 +10713,8 @@
 
   // Reject cases where the vector element type or the scalar element type are
   // not integral or floating point types.
-  if (!VectorEltTy->isArithmeticType() || !ScalarTy->isArithmeticType())
+  if (!VectorEltTy->isArithmeticType(S.Context) ||
+      !ScalarTy->isArithmeticType(S.Context))
     return true;
 
   // The conversion to apply to the scalar before splatting it,
@@ -10727,8 +10755,19 @@
       // expression is instantiated.
       bool CstScalar = Scalar->get()->isValueDependent() ||
                        Scalar->get()->EvaluateAsFloat(Result, S.Context);
-      int Order = S.Context.getFloatingTypeOrder(VectorEltTy, ScalarTy);
-      if (!CstScalar && Order < 0)
+      FloatingRankCompareResult Order =
+          S.Context.getFloatingTypeOrder(VectorEltTy, ScalarTy);
+
+      // Although the GCC Vector Extensions are not part of the C++23 language
+      // standard, we are currently applying the C++23 extended floating point
+      // rules to them. This is in keeping with the spirit of this function and
+      // maintains consistency in handling floating point types
+      if (S.Context.getLangOpts().CPlusPlus23 &&
+          (ScalarTy->isCXX23StandardAndExtendedFpOp(S.Context, VectorEltTy)) &&
+          (Order <= FRCR_Lesser))
+        return true;
+
+      if (!CstScalar && (Order == FRCR_Lesser))
         return true;
 
       // If the scalar cannot be safely casted to the vector element type,
@@ -10785,8 +10824,9 @@
   const VectorType *RHSVecType = RHSType->getAs<VectorType>();
   assert(LHSVecType || RHSVecType);
 
-  if ((LHSVecType && LHSVecType->getElementType()->isBFloat16Type()) ||
-      (RHSVecType && RHSVecType->getElementType()->isBFloat16Type()))
+  if (!Context.getTargetInfo().hasFullBFloat16Type() &&
+      ((LHSVecType && LHSVecType->getElementType()->isBFloat16Type()) ||
+       (RHSVecType && RHSVecType->getElementType()->isBFloat16Type())))
     return ReportInvalid ? InvalidOperands(Loc, LHS, RHS) : QualType();
 
   // AltiVec-style "vector bool op vector bool" combinations are allowed
@@ -11211,7 +11251,8 @@
     return CheckMatrixMultiplyOperands(LHS, RHS, Loc, IsCompAssign);
   // For division, only matrix-by-scalar is supported. Other combinations with
   // matrix types are invalid.
-  if (IsDiv && LHSTy->isConstantMatrixType() && RHSTy->isArithmeticType())
+  if (IsDiv && LHSTy->isConstantMatrixType() &&
+      RHSTy->isArithmeticType(Context))
     return CheckMatrixElementwiseOperands(LHS, RHS, Loc, IsCompAssign);
 
   QualType compType = UsualArithmeticConversions(
@@ -11219,8 +11260,7 @@
   if (LHS.isInvalid() || RHS.isInvalid())
     return QualType();
 
-
-  if (compType.isNull() || !compType->isArithmeticType())
+  if (compType.isNull() || !compType->isArithmeticType(Context))
     return InvalidOperands(Loc, LHS, RHS);
   if (IsDiv) {
     DiagnoseBadDivideOrRemainderValues(*this, LHS, RHS, Loc, IsDiv);
@@ -11594,7 +11634,7 @@
   }
 
   // handle the common case first (both operands are arithmetic).
-  if (!compType.isNull() && compType->isArithmeticType()) {
+  if (!compType.isNull() && compType->isArithmeticType(Context)) {
     if (CompLHSTy) *CompLHSTy = compType;
     return compType;
   }
@@ -11705,7 +11745,7 @@
   // Enforce type constraints: C99 6.5.6p3.
 
   // Handle the common case first (both operands are arithmetic).
-  if (!compType.isNull() && compType->isArithmeticType()) {
+  if (!compType.isNull() && compType->isArithmeticType(Context)) {
     if (CompLHSTy) *CompLHSTy = compType;
     return compType;
   }
@@ -12666,7 +12706,7 @@
     }
     QualType IntType =
         LHSStrippedType->castAs<EnumType>()->getDecl()->getIntegerType();
-    assert(IntType->isArithmeticType());
+    assert(IntType->isArithmeticType(S.Context));
 
     // We can't use `CK_IntegralCast` when the underlying type is 'bool', so we
     // promote the boolean type, and all other promotable integer types, to
@@ -12720,7 +12760,7 @@
     return QualType();
   if (Type.isNull())
     return S.InvalidOperands(Loc, LHS, RHS);
-  assert(Type->isArithmeticType() || Type->isEnumeralType());
+  assert(Type->isArithmeticType(S.Context) || Type->isEnumeralType());
 
   if (Type->isAnyComplexType() && BinaryOperator::isRelationalOp(Opc))
     return S.InvalidOperands(Loc, LHS, RHS);
@@ -12812,8 +12852,8 @@
 
   QualType LHSType = LHS.get()->getType();
   QualType RHSType = RHS.get()->getType();
-  if ((LHSType->isArithmeticType() || LHSType->isEnumeralType()) &&
-      (RHSType->isArithmeticType() || RHSType->isEnumeralType()))
+  if ((LHSType->isArithmeticType(Context) || LHSType->isEnumeralType()) &&
+      (RHSType->isArithmeticType(Context) || RHSType->isEnumeralType()))
     return checkArithmeticOrEnumeralCompare(*this, LHS, RHS, Loc, Opc);
 
   const Expr::NullPointerConstantKind LHSNullKind =
@@ -16014,7 +16054,7 @@
     resultType = Input.get()->getType();
     if (resultType->isDependentType())
       break;
-    if (resultType->isArithmeticType()) // C99 6.5.3.3p1
+    if (resultType->isArithmeticType(Context)) // C99 6.5.3.3p1
       break;
     else if (resultType->isVectorType() &&
              // The z vector extensions don't allow + or - with bool vectors.
Index: clang/lib/Sema/SemaExprCXX.cpp
===================================================================
--- clang/lib/Sema/SemaExprCXX.cpp
+++ clang/lib/Sema/SemaExprCXX.cpp
@@ -5004,9 +5004,9 @@
   case UTT_IsReference:
     return T->isReferenceType();
   case UTT_IsArithmetic:
-    return T->isArithmeticType() && !T->isEnumeralType();
+    return T->isArithmeticType(C) && !T->isEnumeralType();
   case UTT_IsFundamental:
-    return T->isFundamentalType();
+    return T->isFundamentalType(C);
   case UTT_IsObject:
     return T->isObjectType();
   case UTT_IsScalar:
@@ -6712,7 +6712,7 @@
   //   -- The second and third operands have arithmetic or enumeration type;
   //      the usual arithmetic conversions are performed to bring them to a
   //      common type, and the result is of that type.
-  if (LTy->isArithmeticType() && RTy->isArithmeticType()) {
+  if (LTy->isArithmeticType(Context) && RTy->isArithmeticType(Context)) {
     QualType ResTy =
         UsualArithmeticConversions(LHS, RHS, QuestionLoc, ACK_Conditional);
     if (LHS.isInvalid() || RHS.isInvalid())
Index: clang/lib/Sema/SemaObjCProperty.cpp
===================================================================
--- clang/lib/Sema/SemaObjCProperty.cpp
+++ clang/lib/Sema/SemaObjCProperty.cpp
@@ -1386,8 +1386,7 @@
         // specifically for property redeclarations as well as for ivars.
         QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
         QualType rhsType =Context.getCanonicalType(IvarType).getUnqualifiedType();
-        if (lhsType != rhsType &&
-            lhsType->isArithmeticType()) {
+        if (lhsType != rhsType && lhsType->isArithmeticType(Context)) {
           Diag(PropertyDiagLoc, diag::err_property_ivar_type)
             << property->getDeclName() << PropType
             << Ivar->getDeclName() << IvarType;
@@ -1733,7 +1732,7 @@
       compat = true;
       QualType lhsType = Context.getCanonicalType(PropertyRValueType);
       QualType rhsType =Context.getCanonicalType(GetterType).getUnqualifiedType();
-      if (lhsType != rhsType && lhsType->isArithmeticType())
+      if (lhsType != rhsType && lhsType->isArithmeticType(Context))
         compat = false;
     }
   }
Index: clang/lib/Sema/SemaOpenMP.cpp
===================================================================
--- clang/lib/Sema/SemaOpenMP.cpp
+++ clang/lib/Sema/SemaOpenMP.cpp
@@ -19366,7 +19366,7 @@
     if (DeclareReductionRef.isUnset()) {
       if ((BOK == BO_GT || BOK == BO_LT) &&
           !(Type->isScalarType() ||
-            (S.getLangOpts().CPlusPlus && Type->isArithmeticType()))) {
+            (S.getLangOpts().CPlusPlus && Type->isArithmeticType(Context)))) {
         S.Diag(ELoc, diag::err_omp_clause_not_arithmetic_type_arg)
             << getOpenMPClauseName(ClauseKind) << S.getLangOpts().CPlusPlus;
         if (!ASE && !OASE) {
Index: clang/lib/Sema/SemaOverload.cpp
===================================================================
--- clang/lib/Sema/SemaOverload.cpp
+++ clang/lib/Sema/SemaOverload.cpp
@@ -397,7 +397,7 @@
   //    if it cannot be represented exactly), or
   case ICK_Floating_Conversion:
     if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
-        Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
+        Ctx.getFloatingTypeOrder(FromType, ToType) == FRCR_Greater) {
       // FromType is larger than ToType.
       const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
 
@@ -1750,7 +1750,7 @@
       return false;
 
     // Vector splat from any arithmetic type to a vector.
-    if (FromType->isArithmeticType()) {
+    if (FromType->isArithmeticType(S.Context)) {
       ICK = ICK_Vector_Splat;
       return true;
     }
@@ -1969,9 +1969,8 @@
     SCS.Second = ICK_Complex_Promotion;
     FromType = ToType.getUnqualifiedType();
   } else if (ToType->isBooleanType() &&
-             (FromType->isArithmeticType() ||
-              FromType->isAnyPointerType() ||
-              FromType->isBlockPointerType() ||
+             (FromType->isArithmeticType(S.Context) ||
+              FromType->isAnyPointerType() || FromType->isBlockPointerType() ||
               FromType->isMemberPointerType())) {
     // Boolean conversions (C++ 4.12).
     SCS.Second = ICK_Boolean_Conversion;
@@ -1985,8 +1984,10 @@
     // Complex conversions (C99 6.3.1.6)
     SCS.Second = ICK_Complex_Conversion;
     FromType = ToType.getUnqualifiedType();
-  } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
-             (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
+  } else if ((FromType->isAnyComplexType() &&
+              ToType->isArithmeticType(S.Context)) ||
+             (ToType->isAnyComplexType() &&
+              FromType->isArithmeticType(S.Context))) {
     // Complex-real conversions (C99 6.3.1.7)
     SCS.Second = ICK_Complex_Real;
     FromType = ToType.getUnqualifiedType();
@@ -1995,8 +1996,18 @@
     // if their representation is different until there is back end support
     // We of course allow this conversion if long double is really double.
 
+    // C++23 7.3.10p1 [conv.double]
+    // A prvalue of floating-point type can be converted to a prvalue of another
+    // floating-point type with a greater or equal conversion rank
+    // ([conv.rank]). A prvalue of standard floating-point type can be converted
+    // to a prvalue of another standard floating-point type.
+    if ((FromType->isCXX23StandardAndExtendedFpOp(S.Context, ToType)) &&
+        (S.Context.getFloatingTypeOrder(ToType, FromType) <= FRCR_Lesser))
+      return false;
+
     // Conversions between bfloat and other floats are not permitted.
-    if (FromType == S.Context.BFloat16Ty || ToType == S.Context.BFloat16Ty)
+    if (!S.Context.getTargetInfo().hasFullBFloat16Type() &&
+        (FromType->isBFloat16Type() || ToType->isBFloat16Type()))
       return false;
 
     // Conversions between IEEE-quad and IBM-extended semantics are not
@@ -2018,7 +2029,8 @@
              (FromType->isIntegralOrUnscopedEnumerationType() &&
               ToType->isRealFloatingType())) {
     // Conversions between bfloat and int are not permitted.
-    if (FromType->isBFloat16Type() || ToType->isBFloat16Type())
+    if (!S.Context.getTargetInfo().hasFullBFloat16Type() &&
+        (FromType->isBFloat16Type() || ToType->isBFloat16Type()))
       return false;
 
     // Floating-integral conversions (C++ 4.9).
@@ -4166,6 +4178,74 @@
                ? ImplicitConversionSequence::Better
                : ImplicitConversionSequence::Worse;
 
+  // C++23 12.2.4.3p4:
+  // A conversion in either direction between floating-point type FP1 and
+  // floating-point type FP2 is better than a conversion in the same direction
+  // between FP1 and arithmetic type T3 if:
+  // 1) The floating-point conversion rank ([conv.rank]) of FP1 is equal to the
+  // rank of FP2, and 2) T3 is not a floating-point type, or T3 is a
+  // floating-point type whose rank is not equal to the rank of FP1, or the
+  // floating-point conversion subrank ([conv.rank]) of FP2 is greater than the
+  // subrank of T3.
+  if (S.Context.getLangOpts().CPlusPlus23) {
+    if (S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
+
+      if ((SCS1.Second == ICK_Floating_Conversion) &&
+          (SCS1.getFromType()->isCXX23FloatingPointType(S.Context) &&
+           SCS1.getToType(1)->isCXX23FloatingPointType(S.Context)) &&
+          S.Context.getFloatingTypeOrder(SCS1.getToType(1),
+                                         SCS1.getFromType()) >= FRCR_Equal) {
+
+        if ((SCS2.getToType(1)->isArithmeticType(S.Context)) &&
+            SCS2.getFromType()->isCXX23FloatingPointType(S.Context)) {
+
+          if (!SCS2.getToType(1)->isCXX23FloatingPointType(S.Context)) {
+            return ImplicitConversionSequence::Better;
+          }
+
+          if (S.Context.getFloatingTypeOrder(SCS2.getToType(1),
+                                             SCS1.getFromType()) < FRCR_Equal) {
+            return ImplicitConversionSequence::Better;
+          }
+
+          if (S.Context.getFloatingTypeOrder(SCS1.getToType(1),
+                                             SCS2.getToType(1)) ==
+              FRCR_Equal_Greater_Subrank) {
+            return ImplicitConversionSequence::Better;
+          }
+          return ImplicitConversionSequence::Worse;
+        }
+      }
+
+      if ((SCS2.Second == ICK_Floating_Conversion) &&
+          (SCS2.getFromType()->isCXX23FloatingPointType(S.Context) &&
+           SCS2.getToType(1)->isCXX23FloatingPointType(S.Context)) &&
+          S.Context.getFloatingTypeOrder(SCS2.getToType(1),
+                                         SCS2.getFromType()) >= FRCR_Equal) {
+        if ((SCS1.getToType(1)->isArithmeticType(S.Context)) &&
+            SCS1.getFromType()->isCXX23FloatingPointType(S.Context)) {
+
+          if (!SCS1.getToType(1)->isCXX23FloatingPointType(S.Context)) {
+            return ImplicitConversionSequence::Worse;
+          }
+
+          if (S.Context.getFloatingTypeOrder(SCS1.getToType(1),
+                                             SCS2.getFromType()) < FRCR_Equal) {
+            return ImplicitConversionSequence::Worse;
+          }
+
+          if (S.Context.getFloatingTypeOrder(SCS2.getToType(1),
+                                             SCS1.getToType(1)) ==
+              FRCR_Equal_Greater_Subrank) {
+            return ImplicitConversionSequence::Worse;
+          }
+
+          assert(false && "Should not reach here");
+        }
+      }
+    }
+  }
+
   // C++ [over.ics.rank]p4b2:
   //
   //   If class B is derived directly or indirectly from class A,
@@ -8253,7 +8333,7 @@
 
   // Flag if we encounter an arithmetic type.
   HasArithmeticOrEnumeralTypes =
-    HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
+      HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(Context);
 
   if (Ty->isObjCIdType() || Ty->isObjCClassType())
     PointerTypes.insert(Ty);
Index: clang/lib/Sema/SemaType.cpp
===================================================================
--- clang/lib/Sema/SemaType.cpp
+++ clang/lib/Sema/SemaType.cpp
@@ -1519,7 +1519,8 @@
     break;
   case DeclSpec::TST_half:    Result = Context.HalfTy; break;
   case DeclSpec::TST_BFloat16:
-    if (!S.Context.getTargetInfo().hasBFloat16Type() &&
+    if (!(S.Context.getTargetInfo().hasBFloat16Type() ||
+          S.Context.getTargetInfo().hasFullBFloat16Type()) &&
         !(S.getLangOpts().OpenMP && S.getLangOpts().OpenMPIsDevice) &&
         !S.getLangOpts().SYCLIsDevice)
       S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_unsupported) << "__bf16";
Index: clang/test/CodeGen/X86/bfloat-mangle.cpp
===================================================================
--- clang/test/CodeGen/X86/bfloat-mangle.cpp
+++ clang/test/CodeGen/X86/bfloat-mangle.cpp
@@ -3,6 +3,6 @@
 // RUN: %clang_cc1 -triple i386-windows-msvc -target-feature +sse2 -emit-llvm -o - %s | FileCheck %s --check-prefixes=WINDOWS
 // RUN: %clang_cc1 -triple x86_64-windows-msvc -target-feature +sse2 -emit-llvm -o - %s | FileCheck %s --check-prefixes=WINDOWS
 
-// LINUX: define {{.*}}void @_Z3foou6__bf16(bfloat noundef %b)
+// LINUX: define {{.*}}void @_Z3fooDF16b(bfloat noundef %b)
 // WINDOWS: define {{.*}}void @"?foo@@YAXU__bf16@__clang@@@Z"(bfloat noundef %b)
 void foo(__bf16 b) {}
Index: clang/test/CodeGen/vector-bfloat16.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGen/vector-bfloat16.cpp
@@ -0,0 +1,37 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 2
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -target-feature +fullbf16 -S -emit-llvm %s -o - | FileCheck %s
+
+typedef __bf16 v8bfloat16 __attribute__((__vector_size__(16)));
+
+// CHECK-LABEL: define dso_local void @_Z11test_vectorDv8_DF16bS_
+// CHECK-SAME: (<8 x bfloat> noundef [[A:%.*]], <8 x bfloat> noundef [[B:%.*]]) #[[ATTR0:[0-9]+]] {
+// CHECK:         [[A_ADDR:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    [[B_ADDR:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    [[C:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    store <8 x bfloat> [[A]], ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    store <8 x bfloat> [[B]], ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[TMP0:%.*]] = load <8 x bfloat>, ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    [[TMP1:%.*]] = load <8 x bfloat>, ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[ADD:%.*]] = fadd <8 x bfloat> [[TMP0]], [[TMP1]]
+// CHECK-NEXT:    store <8 x bfloat> [[ADD]], ptr [[C]], align 16
+// CHECK-NEXT:    [[TMP2:%.*]] = load <8 x bfloat>, ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    [[TMP3:%.*]] = load <8 x bfloat>, ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[SUB:%.*]] = fsub <8 x bfloat> [[TMP2]], [[TMP3]]
+// CHECK-NEXT:    store <8 x bfloat> [[SUB]], ptr [[C]], align 16
+// CHECK-NEXT:    [[TMP4:%.*]] = load <8 x bfloat>, ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    [[TMP5:%.*]] = load <8 x bfloat>, ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[MUL:%.*]] = fmul <8 x bfloat> [[TMP4]], [[TMP5]]
+// CHECK-NEXT:    store <8 x bfloat> [[MUL]], ptr [[C]], align 16
+// CHECK-NEXT:    [[TMP6:%.*]] = load <8 x bfloat>, ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    [[TMP7:%.*]] = load <8 x bfloat>, ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[DIV:%.*]] = fdiv <8 x bfloat> [[TMP6]], [[TMP7]]
+// CHECK-NEXT:    store <8 x bfloat> [[DIV]], ptr [[C]], align 16
+// CHECK-NEXT:    ret void
+//
+void test_vector(v8bfloat16 a, v8bfloat16 b) {
+    v8bfloat16 c;
+    c = a + b;
+    c = a - b;
+    c = a * b;
+    c = a / b;
+}
\ No newline at end of file
Index: clang/test/CodeGenCUDA/amdgpu-bf16.cu
===================================================================
--- clang/test/CodeGenCUDA/amdgpu-bf16.cu
+++ clang/test/CodeGenCUDA/amdgpu-bf16.cu
@@ -7,7 +7,7 @@
 
 #include "Inputs/cuda.h"
 
-// CHECK-LABEL: @_Z8test_argPu6__bf16u6__bf16(
+// CHECK-LABEL: @_Z8test_argPDF16bDF16b(
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    [[OUT_ADDR:%.*]] = alloca ptr, align 8, addrspace(5)
 // CHECK-NEXT:    [[IN_ADDR:%.*]] = alloca bfloat, align 2, addrspace(5)
@@ -29,7 +29,7 @@
   *out = bf16;
 }
 
-// CHECK-LABEL: @_Z9test_loadPu6__bf16S_(
+// CHECK-LABEL: @_Z9test_loadPDF16bS_(
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    [[OUT_ADDR:%.*]] = alloca ptr, align 8, addrspace(5)
 // CHECK-NEXT:    [[IN_ADDR:%.*]] = alloca ptr, align 8, addrspace(5)
@@ -52,7 +52,7 @@
   *out = bf16;
 }
 
-// CHECK-LABEL: @_Z8test_retu6__bf16(
+// CHECK-LABEL: @_Z8test_retDF16b(
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    [[RETVAL:%.*]] = alloca bfloat, align 2, addrspace(5)
 // CHECK-NEXT:    [[IN_ADDR:%.*]] = alloca bfloat, align 2, addrspace(5)
@@ -66,7 +66,7 @@
   return in;
 }
 
-// CHECK-LABEL: @_Z9test_callu6__bf16(
+// CHECK-LABEL: @_Z9test_callDF16b(
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    [[RETVAL:%.*]] = alloca bfloat, align 2, addrspace(5)
 // CHECK-NEXT:    [[IN_ADDR:%.*]] = alloca bfloat, align 2, addrspace(5)
@@ -74,7 +74,7 @@
 // CHECK-NEXT:    [[IN_ADDR_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[IN_ADDR]] to ptr
 // CHECK-NEXT:    store bfloat [[IN:%.*]], ptr [[IN_ADDR_ASCAST]], align 2
 // CHECK-NEXT:    [[TMP0:%.*]] = load bfloat, ptr [[IN_ADDR_ASCAST]], align 2
-// CHECK-NEXT:    [[CALL:%.*]] = call contract noundef bfloat @_Z8test_retu6__bf16(bfloat noundef [[TMP0]]) #[[ATTR1:[0-9]+]]
+// CHECK-NEXT:    [[CALL:%.*]] = call contract noundef bfloat @_Z8test_retDF16b(bfloat noundef [[TMP0]]) #[[ATTR1:[0-9]+]]
 // CHECK-NEXT:    ret bfloat [[CALL]]
 //
 __device__ __bf16 test_call( __bf16 in) {
Index: clang/test/CodeGenCUDA/bf16.cu
===================================================================
--- clang/test/CodeGenCUDA/bf16.cu
+++ clang/test/CodeGenCUDA/bf16.cu
@@ -6,12 +6,12 @@
 
 #include "Inputs/cuda.h"
 
-// CHECK-LABEL: .visible .func _Z8test_argPu6__bf16u6__bf16(
-// CHECK:        .param .b64 _Z8test_argPu6__bf16u6__bf16_param_0,
-// CHECK:        .param .b16 _Z8test_argPu6__bf16u6__bf16_param_1
+// CHECK-LABEL: .visible .func _Z8test_argPDF16bDF16b(
+// CHECK:        .param .b64 _Z8test_argPDF16bDF16b_param_0,
+// CHECK:        .param .b16 _Z8test_argPDF16bDF16b_param_1
 //
 __device__ void test_arg(__bf16 *out, __bf16 in) {
-// CHECK:         ld.param.b16    %{{h.*}}, [_Z8test_argPu6__bf16u6__bf16_param_1];
+// CHECK:         ld.param.b16    %{{h.*}}, [_Z8test_argPDF16bDF16b_param_1];
   __bf16 bf16 = in;
   *out = bf16;
 // CHECK:         st.b16
@@ -19,23 +19,23 @@
 }
 
 
-// CHECK-LABEL: .visible .func (.param .b32 func_retval0) _Z8test_retu6__bf16(
-// CHECK:         .param .b16 _Z8test_retu6__bf16_param_0
+// CHECK-LABEL: .visible .func (.param .b32 func_retval0) _Z8test_retDF16b(
+// CHECK:         .param .b16 _Z8test_retDF16b_param_0
 __device__ __bf16 test_ret( __bf16 in) {
-// CHECK:        ld.param.b16    %h{{.*}}, [_Z8test_retu6__bf16_param_0];
+// CHECK:        ld.param.b16    %h{{.*}}, [_Z8test_retDF16b_param_0];
   return in;
 // CHECK:        st.param.b16    [func_retval0+0], %h
 // CHECK:        ret;
 }
 
-// CHECK-LABEL: .visible .func  (.param .b32 func_retval0) _Z9test_callu6__bf16(
-// CHECK:        .param .b16 _Z9test_callu6__bf16_param_0
+// CHECK-LABEL: .visible .func  (.param .b32 func_retval0) _Z9test_callDF16b(
+// CHECK:        .param .b16 _Z9test_callDF16b_param_0
 __device__ __bf16 test_call( __bf16 in) {
-// CHECK:        ld.param.b16    %h{{.*}}, [_Z9test_callu6__bf16_param_0];
+// CHECK:        ld.param.b16    %h{{.*}}, [_Z9test_callDF16b_param_0];
 // CHECK:        st.param.b16    [param0+0], %h2;
 // CHECK:        .param .b32 retval0;
 // CHECK:        call.uni (retval0),
-// CHECK-NEXT:   _Z8test_retu6__bf16,
+// CHECK-NEXT:   _Z8test_retDF16b,
 // CHECK-NEXT:   (
 // CHECK-NEXT:   param0
 // CHECK-NEXT    );
Index: clang/test/CodeGenCXX/cxx23-fp-ext-std-names-p1467r9.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGenCXX/cxx23-fp-ext-std-names-p1467r9.cpp
@@ -0,0 +1,499 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --function-signature
+// RUN: %clang_cc1 -std=c++23 -triple x86_64-unknown-linux-gnu -target-feature +fullbf16 -S -emit-llvm %s -o - | FileCheck %s  --check-prefix=CHECK
+
+// CHECK-LABEL: define {{[^@]+}}@_Z1fDF16b
+// CHECK-SAME: (bfloat noundef [[V:%.*]]) #[[ATTR0:[0-9]+]] {
+// CHECK:         [[V_ADDR:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    store bfloat [[V]], ptr [[V_ADDR]], align 2
+// CHECK-NEXT:    ret i32 1
+//
+int f(decltype(0.BF16) v) { return 1; }
+// CHECK-LABEL: define {{[^@]+}}@_Z1fDF16_
+// CHECK-SAME: (half noundef [[V:%.*]]) #[[ATTR0]] {
+// CHECK:         [[V_ADDR:%.*]] = alloca half, align 2
+// CHECK-NEXT:    store half [[V]], ptr [[V_ADDR]], align 2
+// CHECK-NEXT:    ret i32 1
+//
+int f(_Float16 v) { return 1; }
+// CHECK-LABEL: define {{[^@]+}}@_Z1ff
+// CHECK-SAME: (float noundef [[V:%.*]]) #[[ATTR0]] {
+// CHECK:         [[V_ADDR:%.*]] = alloca float, align 4
+// CHECK-NEXT:    store float [[V]], ptr [[V_ADDR]], align 4
+// CHECK-NEXT:    ret i32 1
+//
+int f(float v) { return 1; }
+// CHECK-LABEL: define {{[^@]+}}@_Z1fd
+// CHECK-SAME: (double noundef [[V:%.*]]) #[[ATTR0]] {
+// CHECK:         [[V_ADDR:%.*]] = alloca double, align 8
+// CHECK-NEXT:    store double [[V]], ptr [[V_ADDR]], align 8
+// CHECK-NEXT:    ret i32 1
+//
+int f(double v) { return 1; }
+// CHECK-LABEL: define {{[^@]+}}@_Z1fe
+// CHECK-SAME: (x86_fp80 noundef [[V:%.*]]) #[[ATTR0]] {
+// CHECK:         [[V_ADDR:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    store x86_fp80 [[V]], ptr [[V_ADDR]], align 16
+// CHECK-NEXT:    ret i32 1
+//
+int f(long double v) { return 1; }
+// CHECK-LABEL: define {{[^@]+}}@_Z1fi
+// CHECK-SAME: (i32 noundef [[V:%.*]]) #[[ATTR0]] {
+// CHECK:         [[V_ADDR:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    store i32 [[V]], ptr [[V_ADDR]], align 4
+// CHECK-NEXT:    ret i32 1
+//
+int f(int v) { return 1; }
+
+// CHECK-LABEL: define {{[^@]+}}@_Z3f_2e
+// CHECK-SAME: (x86_fp80 noundef [[V:%.*]]) #[[ATTR0]] {
+// CHECK:         [[V_ADDR:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    store x86_fp80 [[V]], ptr [[V_ADDR]], align 16
+// CHECK-NEXT:    ret i32 1
+//
+int f_2(long double v) { return 1; }
+
+struct S {
+
+    operator decltype(0.BF16)() const {
+        return 0.0bf16;
+    }
+
+    operator _Float16() const {
+        return 0.0f16;
+    }
+
+    operator float() const {
+        return 0.0f;
+    }
+
+    operator double() const {
+        return 0.0;
+    }
+
+    operator long double() const {
+        return 0.0L;
+    }
+
+    operator int() const {
+        return 0;
+    }
+};
+
+struct S1 {
+    operator _Float16() const {
+        return 0.0f16;
+    }
+    operator float() const {
+        return 0.0f;
+    }
+    operator double() const {
+        return 0.0;
+    }
+    operator long double() const {
+        return 0.0L;
+    }
+
+    operator int() const {
+        return 0;
+    }
+};
+
+// CHECK-LABEL: define {{[^@]+}}@_Z5test1v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[F16_VAL_6:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_VAL_8:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_VAL_9:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_VAL_10:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_VAL_11:%.*]] = alloca half, align 2
+// CHECK-NEXT:    store half 0xH3C00, ptr [[F16_VAL_6]], align 2
+// CHECK-NEXT:    store half 0xH3C00, ptr [[F16_VAL_8]], align 2
+// CHECK-NEXT:    store half 0xH3C00, ptr [[F16_VAL_9]], align 2
+// CHECK-NEXT:    store half 0xH3C00, ptr [[F16_VAL_10]], align 2
+// CHECK-NEXT:    store half 0xH3C00, ptr [[F16_VAL_11]], align 2
+// CHECK-NEXT:    ret void
+//
+void test1() {
+    _Float16 f16_val_6 = 1.0f16;
+    _Float16 f16_val_8 = static_cast<_Float16>(1.0f);
+    _Float16 f16_val_9 = static_cast<_Float16>(1.0);
+    _Float16 f16_val_10 = static_cast<_Float16>(1.0l);
+    _Float16 f16_val_11 = static_cast<_Float16>(1.0f16);
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z5test2v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[BF16_VAL_5:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_VAL_7:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_VAL_8:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_VAL_9:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_VAL_10:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    store bfloat 0xR3F80, ptr [[BF16_VAL_5]], align 2
+// CHECK-NEXT:    store bfloat 0xR3F80, ptr [[BF16_VAL_7]], align 2
+// CHECK-NEXT:    store bfloat 0xR3F80, ptr [[BF16_VAL_8]], align 2
+// CHECK-NEXT:    store bfloat 0xR3F80, ptr [[BF16_VAL_9]], align 2
+// CHECK-NEXT:    store bfloat 0xR3F80, ptr [[BF16_VAL_10]], align 2
+// CHECK-NEXT:    ret void
+//
+void test2() {
+    decltype(0.BF16) bf16_val_5 = 1.0bf16;
+    decltype(0.BF16) bf16_val_7 = static_cast<decltype(0.BF16)>(1.0f);
+    decltype(0.BF16) bf16_val_8 = static_cast<decltype(0.BF16)>(1.0);
+    decltype(0.BF16) bf16_val_9 = static_cast<decltype(0.BF16)>(1.0l);
+    decltype(0.BF16) bf16_val_10 = static_cast<decltype(0.BF16)>(1.0bf16);
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z5test3v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[F_VAL_1:%.*]] = alloca float, align 4
+// CHECK-NEXT:    [[F_VAL_2:%.*]] = alloca float, align 4
+// CHECK-NEXT:    [[F_VAL_3:%.*]] = alloca float, align 4
+// CHECK-NEXT:    [[F_VAL_4:%.*]] = alloca float, align 4
+// CHECK-NEXT:    [[F_VAL_5:%.*]] = alloca float, align 4
+// CHECK-NEXT:    store float 1.000000e+00, ptr [[F_VAL_1]], align 4
+// CHECK-NEXT:    store float 1.000000e+00, ptr [[F_VAL_2]], align 4
+// CHECK-NEXT:    store float 1.000000e+00, ptr [[F_VAL_3]], align 4
+// CHECK-NEXT:    store float 1.000000e+00, ptr [[F_VAL_4]], align 4
+// CHECK-NEXT:    store float 1.000000e+00, ptr [[F_VAL_5]], align 4
+// CHECK-NEXT:    ret void
+//
+void test3() {
+    float f_val_1 = 1.0f16;
+    float f_val_2 = 1.0bf16;
+    float f_val_3 = 1.0;
+    float f_val_4 = 1.0l;
+    float f_val_5 = 1.0f;
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z5test4v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[D_VAL_1:%.*]] = alloca double, align 8
+// CHECK-NEXT:    [[D_VAL_2:%.*]] = alloca double, align 8
+// CHECK-NEXT:    [[D_VAL_3:%.*]] = alloca double, align 8
+// CHECK-NEXT:    [[D_VAL_4:%.*]] = alloca double, align 8
+// CHECK-NEXT:    [[D_VAL_5:%.*]] = alloca double, align 8
+// CHECK-NEXT:    store double 1.000000e+00, ptr [[D_VAL_1]], align 8
+// CHECK-NEXT:    store double 1.000000e+00, ptr [[D_VAL_2]], align 8
+// CHECK-NEXT:    store double 1.000000e+00, ptr [[D_VAL_3]], align 8
+// CHECK-NEXT:    store double 1.000000e+00, ptr [[D_VAL_4]], align 8
+// CHECK-NEXT:    store double 1.000000e+00, ptr [[D_VAL_5]], align 8
+// CHECK-NEXT:    ret void
+//
+void test4() {
+    double d_val_1 = 1.0f16;
+    double d_val_2 = 1.0bf16;
+    double d_val_3 = 1.0f;
+    double d_val_4 = 1.0l;
+    double d_val_5 = 1.0;
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z5test5v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[LD_VAL_1:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    [[LD_VAL_2:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    [[LD_VAL_3:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    [[LD_VAL_4:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    [[LD_VAL_5:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    store x86_fp80 0xK3FFF8000000000000000, ptr [[LD_VAL_1]], align 16
+// CHECK-NEXT:    store x86_fp80 0xK3FFF8000000000000000, ptr [[LD_VAL_2]], align 16
+// CHECK-NEXT:    store x86_fp80 0xK3FFF8000000000000000, ptr [[LD_VAL_3]], align 16
+// CHECK-NEXT:    store x86_fp80 0xK3FFF8000000000000000, ptr [[LD_VAL_4]], align 16
+// CHECK-NEXT:    store x86_fp80 0xK3FFF8000000000000000, ptr [[LD_VAL_5]], align 16
+// CHECK-NEXT:    ret void
+//
+void test5() {
+    long double ld_val_1 = 1.0f16;
+    long double ld_val_2 = 1.0bf16;
+    long double ld_val_3 = 1.0f;
+    long double ld_val_4 = 1.0;
+    long double ld_val_5 = 1.0l;
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z5test6v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[F16_FLOAT:%.*]] = alloca float, align 4
+// CHECK-NEXT:    [[F16_DOUBLE:%.*]] = alloca double, align 8
+// CHECK-NEXT:    [[F16_LDOUBLE:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    [[F16_INT:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_UINT:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_LONG:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_ULONG:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_LLONG:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_ULLONG:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[F16_BOOL:%.*]] = alloca half, align 2
+// CHECK-NEXT:    store float 2.000000e+00, ptr [[F16_FLOAT]], align 4
+// CHECK-NEXT:    store double 2.000000e+00, ptr [[F16_DOUBLE]], align 8
+// CHECK-NEXT:    store x86_fp80 0xK40008000000000000000, ptr [[F16_LDOUBLE]], align 16
+// CHECK-NEXT:    store half 0xH4000, ptr [[F16_INT]], align 2
+// CHECK-NEXT:    store half 0xH4000, ptr [[F16_UINT]], align 2
+// CHECK-NEXT:    store half 0xH4000, ptr [[F16_LONG]], align 2
+// CHECK-NEXT:    store half 0xH4000, ptr [[F16_ULONG]], align 2
+// CHECK-NEXT:    store half 0xH4000, ptr [[F16_LLONG]], align 2
+// CHECK-NEXT:    store half 0xH4000, ptr [[F16_ULLONG]], align 2
+// CHECK-NEXT:    store half 0xH4000, ptr [[F16_BOOL]], align 2
+// CHECK-NEXT:    ret void
+//
+void test6() {
+    auto f16_float = 1.0f16 + 1.0f;
+    auto f16_double = 1.0f16 + 1.0;
+    auto f16_ldouble = 1.0f16 + 1.0l;
+    auto f16_int = 1.0f16 + 1;
+    auto f16_uint = 1.0f16 + 1u;
+    auto f16_long = 1.0f16 + 1l;
+    auto f16_ulong = 1.0f16 + 1ul;
+    auto f16_llong = 1.0f16 + 1ll;
+    auto f16_ullong = 1.0f16 + 1ull;
+    auto f16_bool = 1.0f16 + true;
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z5test7v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[BF16_FLOAT:%.*]] = alloca float, align 4
+// CHECK-NEXT:    [[BF16_DOUBLE:%.*]] = alloca double, align 8
+// CHECK-NEXT:    [[BF16_LDOUBLE:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    [[BF16_INT:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_UINT:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_LONG:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_ULONG:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_LLONG:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_ULLONG:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[BF16_BOOL:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    store float 2.000000e+00, ptr [[BF16_FLOAT]], align 4
+// CHECK-NEXT:    store double 2.000000e+00, ptr [[BF16_DOUBLE]], align 8
+// CHECK-NEXT:    store x86_fp80 0xK40008000000000000000, ptr [[BF16_LDOUBLE]], align 16
+// CHECK-NEXT:    store bfloat 0xR4000, ptr [[BF16_INT]], align 2
+// CHECK-NEXT:    store bfloat 0xR4000, ptr [[BF16_UINT]], align 2
+// CHECK-NEXT:    store bfloat 0xR4000, ptr [[BF16_LONG]], align 2
+// CHECK-NEXT:    store bfloat 0xR4000, ptr [[BF16_ULONG]], align 2
+// CHECK-NEXT:    store bfloat 0xR4000, ptr [[BF16_LLONG]], align 2
+// CHECK-NEXT:    store bfloat 0xR4000, ptr [[BF16_ULLONG]], align 2
+// CHECK-NEXT:    store bfloat 0xR4000, ptr [[BF16_BOOL]], align 2
+// CHECK-NEXT:    ret void
+//
+void test7() {
+    auto bf16_float = 1.0bf16 + 1.0f;
+    //
+    auto bf16_double = 1.0bf16 + 1.0;
+    auto bf16_ldouble = 1.0bf16 + 1.0l;
+    auto bf16_int = 1.0bf16 + 1;
+    auto bf16_uint = 1.0bf16 + 1u;
+    auto bf16_long = 1.0bf16 + 1l;
+    auto bf16_ulong = 1.0bf16 + 1ul;
+    auto bf16_llong = 1.0bf16 + 1ll;
+    auto bf16_ullong = 1.0bf16 + 1ull;
+    auto bf16_bool = 1.0bf16 + true;
+}
+
+//
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test8_1v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[BF16_VAL:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[TEST1:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[TEST_9:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    store bfloat 0xR3F80, ptr [[BF16_VAL]], align 2
+// CHECK-NEXT:    [[TMP0:%.*]] = load bfloat, ptr [[BF16_VAL]], align 2
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef i32 @_Z1fDF16b(bfloat noundef [[TMP0]])
+// CHECK-NEXT:    store i32 [[CALL]], ptr [[TEST1]], align 4
+// CHECK-NEXT:    [[TMP1:%.*]] = load bfloat, ptr [[BF16_VAL]], align 2
+// CHECK-NEXT:    [[CONV:%.*]] = fpext bfloat [[TMP1]] to x86_fp80
+// CHECK-NEXT:    [[CALL1:%.*]] = call noundef i32 @_Z3f_2e(x86_fp80 noundef [[CONV]])
+// CHECK-NEXT:    store i32 [[CALL1]], ptr [[TEST_9]], align 4
+// CHECK-NEXT:    ret void
+//
+void test8_1() {
+    decltype(0.BF16) bf16_val = 1.0bf16;
+    int test1 = f(bf16_val); // calls f(decltype(0.BF16))
+    int test_9 = f_2(bf16_val);
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test8_2v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[FLOAT16_VAL:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[TEST2:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[TEST_10:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    store half 0xH3C00, ptr [[FLOAT16_VAL]], align 2
+// CHECK-NEXT:    [[TMP0:%.*]] = load half, ptr [[FLOAT16_VAL]], align 2
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef i32 @_Z1fDF16_(half noundef [[TMP0]])
+// CHECK-NEXT:    store i32 [[CALL]], ptr [[TEST2]], align 4
+// CHECK-NEXT:    [[TMP1:%.*]] = load half, ptr [[FLOAT16_VAL]], align 2
+// CHECK-NEXT:    [[CONV:%.*]] = fpext half [[TMP1]] to x86_fp80
+// CHECK-NEXT:    [[CALL1:%.*]] = call noundef i32 @_Z3f_2e(x86_fp80 noundef [[CONV]])
+// CHECK-NEXT:    store i32 [[CALL1]], ptr [[TEST_10]], align 4
+// CHECK-NEXT:    ret void
+//
+void test8_2() {
+    _Float16 float16_val = 1.0f16;
+    int test2 = f(float16_val); // calls f(_Float16)
+    int test_10 = f_2(float16_val);
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test8_3v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[FLOAT_VAL:%.*]] = alloca float, align 4
+// CHECK-NEXT:    [[TEST3:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[TEST_7:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    store float 1.000000e+00, ptr [[FLOAT_VAL]], align 4
+// CHECK-NEXT:    [[TMP0:%.*]] = load float, ptr [[FLOAT_VAL]], align 4
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef i32 @_Z1ff(float noundef [[TMP0]])
+// CHECK-NEXT:    store i32 [[CALL]], ptr [[TEST3]], align 4
+// CHECK-NEXT:    [[TMP1:%.*]] = load float, ptr [[FLOAT_VAL]], align 4
+// CHECK-NEXT:    [[CONV:%.*]] = fpext float [[TMP1]] to x86_fp80
+// CHECK-NEXT:    [[CALL1:%.*]] = call noundef i32 @_Z3f_2e(x86_fp80 noundef [[CONV]])
+// CHECK-NEXT:    store i32 [[CALL1]], ptr [[TEST_7]], align 4
+// CHECK-NEXT:    ret void
+//
+void test8_3() {
+    float float_val = 1.0f;
+    int test3 = f(float_val); // calls f(float)
+    int test_7 = f_2(float_val);
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test8_4v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[DOUBLE_VAL:%.*]] = alloca double, align 8
+// CHECK-NEXT:    [[TEST4:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[TEST_8:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    store double 1.000000e+00, ptr [[DOUBLE_VAL]], align 8
+// CHECK-NEXT:    [[TMP0:%.*]] = load double, ptr [[DOUBLE_VAL]], align 8
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef i32 @_Z1fd(double noundef [[TMP0]])
+// CHECK-NEXT:    store i32 [[CALL]], ptr [[TEST4]], align 4
+// CHECK-NEXT:    [[TMP1:%.*]] = load double, ptr [[DOUBLE_VAL]], align 8
+// CHECK-NEXT:    [[CONV:%.*]] = fpext double [[TMP1]] to x86_fp80
+// CHECK-NEXT:    [[CALL1:%.*]] = call noundef i32 @_Z3f_2e(x86_fp80 noundef [[CONV]])
+// CHECK-NEXT:    store i32 [[CALL1]], ptr [[TEST_8]], align 4
+// CHECK-NEXT:    ret void
+//
+void test8_4() {
+    double double_val = 1.0;
+    int test4 = f(double_val); // calls f(double)
+    int test_8 = f_2(double_val);
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test8_5v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[LONG_DOUBLE_VAL:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    [[TEST5:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    store x86_fp80 0xK3FFF8000000000000000, ptr [[LONG_DOUBLE_VAL]], align 16
+// CHECK-NEXT:    [[TMP0:%.*]] = load x86_fp80, ptr [[LONG_DOUBLE_VAL]], align 16
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef i32 @_Z1fe(x86_fp80 noundef [[TMP0]])
+// CHECK-NEXT:    store i32 [[CALL]], ptr [[TEST5]], align 4
+// CHECK-NEXT:    ret void
+//
+void test8_5() {
+    long double long_double_val = 1.0l;
+    int test5 = f(long_double_val); // calls f(long double)
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test8_6v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[INT_VAL:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[TEST6:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    store i32 1, ptr [[INT_VAL]], align 4
+// CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[INT_VAL]], align 4
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef i32 @_Z1fi(i32 noundef [[TMP0]])
+// CHECK-NEXT:    store i32 [[CALL]], ptr [[TEST6]], align 4
+// CHECK-NEXT:    ret void
+//
+void test8_6() {
+    int int_val = 1;
+    int test6 = f(int_val); // calls f(int)
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test9_1v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[USER_DEFINED_VAL:%.*]] = alloca [[STRUCT_S:%.*]], align 1
+// CHECK-NEXT:    [[BFLOAT16_VAL:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef bfloat @_ZNK1ScvDF16bEv(ptr noundef nonnull align 1 dereferenceable(1) [[USER_DEFINED_VAL]])
+// CHECK-NEXT:    store bfloat [[CALL]], ptr [[BFLOAT16_VAL]], align 2
+// CHECK-NEXT:    ret void
+//
+void test9_1() {
+    S user_defined_val;
+    // User-defined overload cases
+    decltype(0.BF16) bfloat16_val(user_defined_val); // calls operator decltype(0.BF16)()
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test9_2v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[USER_DEFINED_VAL:%.*]] = alloca [[STRUCT_S:%.*]], align 1
+// CHECK-NEXT:    [[F16_VAL:%.*]] = alloca half, align 2
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef half @_ZNK1ScvDF16_Ev(ptr noundef nonnull align 1 dereferenceable(1) [[USER_DEFINED_VAL]])
+// CHECK-NEXT:    store half [[CALL]], ptr [[F16_VAL]], align 2
+// CHECK-NEXT:    ret void
+//
+void test9_2() {
+    S user_defined_val;
+    // User-defined overload cases
+    _Float16 f16_val(user_defined_val); // calls operator _Float16()
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test9_3v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[USER_DEFINED_VAL:%.*]] = alloca [[STRUCT_S:%.*]], align 1
+// CHECK-NEXT:    [[F_VAL:%.*]] = alloca float, align 4
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef float @_ZNK1ScvfEv(ptr noundef nonnull align 1 dereferenceable(1) [[USER_DEFINED_VAL]])
+// CHECK-NEXT:    store float [[CALL]], ptr [[F_VAL]], align 4
+// CHECK-NEXT:    ret void
+//
+void test9_3() {
+    S user_defined_val;
+    // User-defined overload cases
+    float f_val(user_defined_val); // calls operator float()
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test9_4v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[USER_DEFINED_VAL:%.*]] = alloca [[STRUCT_S:%.*]], align 1
+// CHECK-NEXT:    [[D_VAL:%.*]] = alloca double, align 8
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef double @_ZNK1ScvdEv(ptr noundef nonnull align 1 dereferenceable(1) [[USER_DEFINED_VAL]])
+// CHECK-NEXT:    store double [[CALL]], ptr [[D_VAL]], align 8
+// CHECK-NEXT:    ret void
+//
+void test9_4() {
+    S user_defined_val;
+    // User-defined overload cases
+    double d_val(user_defined_val); // calls operator double()
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test9_5v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[USER_DEFINED_VAL:%.*]] = alloca [[STRUCT_S:%.*]], align 1
+// CHECK-NEXT:    [[LD_VAL:%.*]] = alloca x86_fp80, align 16
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef x86_fp80 @_ZNK1ScveEv(ptr noundef nonnull align 1 dereferenceable(1) [[USER_DEFINED_VAL]])
+// CHECK-NEXT:    store x86_fp80 [[CALL]], ptr [[LD_VAL]], align 16
+// CHECK-NEXT:    ret void
+//
+void test9_5() {
+    S user_defined_val;
+    // User-defined overload cases
+    long double ld_val(user_defined_val); // calls operator long double()
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test9_6v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[USER_DEFINED_VAL:%.*]] = alloca [[STRUCT_S:%.*]], align 1
+// CHECK-NEXT:    [[I_VAL:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef i32 @_ZNK1ScviEv(ptr noundef nonnull align 1 dereferenceable(1) [[USER_DEFINED_VAL]])
+// CHECK-NEXT:    store i32 [[CALL]], ptr [[I_VAL]], align 4
+// CHECK-NEXT:    ret void
+//
+void test9_6() {
+    S user_defined_val;
+    // User-defined overload cases
+    int i_val(user_defined_val); // calls operator int()
+}
+
+// CHECK-LABEL: define {{[^@]+}}@_Z7test9_7v
+// CHECK-SAME: () #[[ATTR0]] {
+// CHECK:         [[USER_DEFINED_VAL_2:%.*]] = alloca [[STRUCT_S1:%.*]], align 1
+// CHECK-NEXT:    [[BFLOAT16_VAL_2:%.*]] = alloca bfloat, align 2
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef i32 @_ZNK2S1cviEv(ptr noundef nonnull align 1 dereferenceable(1) [[USER_DEFINED_VAL_2]])
+// CHECK-NEXT:    [[CONV:%.*]] = sitofp i32 [[CALL]] to bfloat
+// CHECK-NEXT:    store bfloat [[CONV]], ptr [[BFLOAT16_VAL_2]], align 2
+// CHECK-NEXT:    ret void
+//
+void test9_7() {
+    S1 user_defined_val_2;
+    // User-defined overload cases
+    decltype(0.BF16) bfloat16_val_2(user_defined_val_2); // calls operator int()
+}
Index: clang/test/CodeGenCXX/cxx23-vector-bfloat16.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGenCXX/cxx23-vector-bfloat16.cpp
@@ -0,0 +1,67 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 2
+// RUN: %clang_cc1 -std=c++23 -triple x86_64-unknown-linux-gnu -target-feature +fullbf16 -S -emit-llvm %s -o - | FileCheck %s
+
+typedef decltype(0.0BF16) v8bfloat16 __attribute__((__vector_size__(16)));
+
+// CHECK-LABEL: define dso_local void @_Z11test_vectorDv8_DF16bS_
+// CHECK-SAME: (<8 x bfloat> noundef [[A:%.*]], <8 x bfloat> noundef [[B:%.*]]) #[[ATTR0:[0-9]+]] {
+// CHECK:         [[A_ADDR:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    [[B_ADDR:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    [[C:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    store <8 x bfloat> [[A]], ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    store <8 x bfloat> [[B]], ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[TMP0:%.*]] = load <8 x bfloat>, ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    [[TMP1:%.*]] = load <8 x bfloat>, ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[ADD:%.*]] = fadd <8 x bfloat> [[TMP0]], [[TMP1]]
+// CHECK-NEXT:    store <8 x bfloat> [[ADD]], ptr [[C]], align 16
+// CHECK-NEXT:    [[TMP2:%.*]] = load <8 x bfloat>, ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    [[TMP3:%.*]] = load <8 x bfloat>, ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[SUB:%.*]] = fsub <8 x bfloat> [[TMP2]], [[TMP3]]
+// CHECK-NEXT:    store <8 x bfloat> [[SUB]], ptr [[C]], align 16
+// CHECK-NEXT:    [[TMP4:%.*]] = load <8 x bfloat>, ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    [[TMP5:%.*]] = load <8 x bfloat>, ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[MUL:%.*]] = fmul <8 x bfloat> [[TMP4]], [[TMP5]]
+// CHECK-NEXT:    store <8 x bfloat> [[MUL]], ptr [[C]], align 16
+// CHECK-NEXT:    [[TMP6:%.*]] = load <8 x bfloat>, ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    [[TMP7:%.*]] = load <8 x bfloat>, ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[DIV:%.*]] = fdiv <8 x bfloat> [[TMP6]], [[TMP7]]
+// CHECK-NEXT:    store <8 x bfloat> [[DIV]], ptr [[C]], align 16
+// CHECK-NEXT:    ret void
+//
+void test_vector(v8bfloat16 a, v8bfloat16 b) {
+    v8bfloat16 c;
+    c = a + b;
+    c = a - b;
+    c = a * b;
+    c = a / b;
+}
+
+// CHECK-LABEL: define dso_local void @_Z13test_vector_2v
+// CHECK-SAME: () #[[ATTR1:[0-9]+]] {
+// CHECK:         [[A:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    [[DOTCOMPOUNDLITERAL:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    [[B:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    [[DOTCOMPOUNDLITERAL1:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    [[C:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    [[D:%.*]] = alloca <8 x bfloat>, align 16
+// CHECK-NEXT:    store <8 x bfloat> zeroinitializer, ptr [[DOTCOMPOUNDLITERAL]], align 16
+// CHECK-NEXT:    [[TMP0:%.*]] = load <8 x bfloat>, ptr [[DOTCOMPOUNDLITERAL]], align 16
+// CHECK-NEXT:    store <8 x bfloat> [[TMP0]], ptr [[A]], align 16
+// CHECK-NEXT:    store <8 x bfloat> <bfloat 0xR3F80, bfloat 0xR0000, bfloat 0xR0000, bfloat 0xR0000, bfloat 0xR0000, bfloat 0xR0000, bfloat 0xR0000, bfloat 0xR0000>, ptr [[DOTCOMPOUNDLITERAL1]], align 16
+// CHECK-NEXT:    [[TMP1:%.*]] = load <8 x bfloat>, ptr [[DOTCOMPOUNDLITERAL1]], align 16
+// CHECK-NEXT:    store <8 x bfloat> [[TMP1]], ptr [[B]], align 16
+// CHECK-NEXT:    [[TMP2:%.*]] = load <8 x bfloat>, ptr [[A]], align 16
+// CHECK-NEXT:    [[ELT_ABS:%.*]] = call <8 x bfloat> @llvm.fabs.v8bf16(<8 x bfloat> [[TMP2]])
+// CHECK-NEXT:    store <8 x bfloat> [[ELT_ABS]], ptr [[C]], align 16
+// CHECK-NEXT:    [[TMP3:%.*]] = load <8 x bfloat>, ptr [[C]], align 16
+// CHECK-NEXT:    [[ELT_ABS2:%.*]] = call <8 x bfloat> @llvm.fabs.v8bf16(<8 x bfloat> [[TMP3]])
+// CHECK-NEXT:    store <8 x bfloat> [[ELT_ABS2]], ptr [[D]], align 16
+// CHECK-NEXT:    ret void
+//
+void test_vector_2() {
+    v8bfloat16 a = (v8bfloat16){0.0bf16};
+    v8bfloat16 b = (v8bfloat16){1.0bf16};
+    v8bfloat16 c = __builtin_elementwise_abs(a);
+    v8bfloat16 d = __builtin_elementwise_abs(c);
+}
+
Index: clang/test/Sema/cxx23-fp-ext-std-names-p1467r9.cpp
===================================================================
--- /dev/null
+++ clang/test/Sema/cxx23-fp-ext-std-names-p1467r9.cpp
@@ -0,0 +1,465 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++23 -target-feature +fullbf16 -verify -ast-dump %s | FileCheck %s
+
+_Float16 f16_val_1 = 1.0bf16; // expected-error {{cannot initialize a variable of type '_Float16' with an rvalue of type '__bf16'}}
+_Float16 f16_val_2 = 1.0f; // expected-error {{cannot initialize a variable of type '_Float16' with an rvalue of type 'float'}}
+_Float16 f16_val_3 = 1.0; // expected-error {{cannot initialize a variable of type '_Float16' with an rvalue of type 'double'}}
+_Float16 f16_val_4 = 1.0l; // expected-error {{cannot initialize a variable of type '_Float16' with an rvalue of type 'long double'}}
+_Float16 f16_val_6 = 1.0f16;
+//CHECK:      VarDecl {{.*}} f16_val_6 '_Float16' cinit
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+_Float16 f16_val_7 = static_cast<_Float16>(1.0bf16); // expected-error {{static_cast from '__bf16' to '_Float16' is not allowed}}
+_Float16 f16_val_8 = static_cast<_Float16>(1.0f);
+//CHECK:      VarDecl {{.*}} f16_val_8 '_Float16' cinit
+//CHECK-NEXT: CXXStaticCastExpr {{.*}} '_Float16' static_cast<_Float16> <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'float' 1.000000e+00
+_Float16 f16_val_9 = static_cast<_Float16>(1.0);
+//CHECK:      VarDecl {{.*}} f16_val_9 '_Float16' cinit
+//CHECK-NEXT: CXXStaticCastExpr {{.*}} '_Float16' static_cast<_Float16> <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'double' 1.000000e+00
+_Float16 f16_val_10 = static_cast<_Float16>(1.0l);
+//CHECK:      VarDecl {{.*}} f16_val_10 '_Float16' cinit
+//CHECK-NEXT: CXXStaticCastExpr {{.*}} '_Float16' static_cast<_Float16> <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'long double' 1.000000e+00
+_Float16 f16_val_11 = static_cast<_Float16>(1.0f16);
+//CHECK:      VarDecl {{.*}} f16_val_11 '_Float16' cinit
+//CHECK-NEXT: CXXStaticCastExpr {{.*}} '_Float16' static_cast<_Float16> <NoOp>
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+
+decltype(0.0BF16) bf16_val_1 = 1.0f16; // expected-error {{cannot initialize a variable of type 'decltype(0.BF16)' (aka '__bf16') with an rvalue of type '_Float16'}}
+decltype(0.0BF16) bf16_val_2 = 1.0f; // expected-error {{cannot initialize a variable of type 'decltype(0.BF16)' (aka '__bf16') with an rvalue of type 'float'}}
+decltype(0.0BF16) bf16_val_3 = 1.0; // expected-error {{cannot initialize a variable of type 'decltype(0.BF16)' (aka '__bf16') with an rvalue of type 'double'}}
+decltype(0.0BF16) bf16_val_4 = 1.0l; // expected-error {{cannot initialize a variable of type 'decltype(0.BF16)' (aka '__bf16') with an rvalue of type 'long double'}}
+decltype(0.0BF16) bf16_val_5 = 1.0bf16;
+//CHECK:      VarDecl {{.*}} bf16_val_5 'decltype(0.BF16)':'__bf16' cinit
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+
+decltype(0.0BF16) bf16_val_6 = static_cast<decltype(0.0BF16)>(1.0f16); // expected-error {{static_cast from '_Float16' to 'decltype(0.BF16)' (aka '__bf16') is not allowed}}
+decltype(0.0BF16) bf16_val_7 = static_cast<decltype(0.0BF16)>(1.0f);
+//CHECK:      VarDecl {{.*}} bf16_val_7 'decltype(0.BF16)':'__bf16' cinit
+//CHECK-NEXT: CXXStaticCastExpr {{.*}} 'decltype(0.BF16)':'__bf16' static_cast<decltype(0.BF16)> <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'float' 1.000000e+00
+decltype(0.0BF16) bf16_val_8 = static_cast<decltype(0.0BF16)>(1.0);
+//CHECK:      VarDecl {{.*}} bf16_val_8 'decltype(0.BF16)':'__bf16' cinit
+//CHECK-NEXT: CXXStaticCastExpr {{.*}} 'decltype(0.BF16)':'__bf16' static_cast<decltype(0.BF16)> <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'double' 1.000000e+00
+decltype(0.0BF16) bf16_val_9 = static_cast<decltype(0.0BF16)>(1.0l);
+//CHECK:      VarDecl {{.*}} bf16_val_9 'decltype(0.BF16)':'__bf16' cinit
+//CHECK-NEXT: CXXStaticCastExpr {{.*}} 'decltype(0.BF16)':'__bf16' static_cast<decltype(0.BF16)> <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'long double' 1.000000e+00
+decltype(0.0BF16) bf16_val_10 = static_cast<decltype(0.0BF16)>(1.0bf16);
+//CHECK:      VarDecl {{.*}} bf16_val_10 'decltype(0.BF16)':'__bf16' cinit
+//CHECK-NEXT: CXXStaticCastExpr {{.*}} 'decltype(0.BF16)':'__bf16' static_cast<decltype(0.BF16)> <NoOp>
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+
+float f_val_1 = 1.0f16;
+//CHECK:      VarDecl {{.*}} f_val_1 'float' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+float f_val_2 = 1.0bf16;
+//CHECK:      VarDecl {{.*}} f_val_2 'float' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+float f_val_3 = 1.0;
+//CHECK:      VarDecl {{.*}} f_val_3 'float' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'double' 1.000000e+00
+float f_val_4 = 1.0l;
+//CHECK:      VarDecl {{.*}} f_val_4 'float' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'long double' 1.000000e+00
+float f_val_5 = 1.0f;
+//CHECK:      VarDecl {{.*}} f_val_5 'float' cinit
+//CHECK-NEXT: FloatingLiteral {{.*}} 'float' 1.000000e+00
+
+double d_val_1 = 1.0f16;
+//CHECK:      VarDecl {{.*}} d_val_1 'double' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+double d_val_2 = 1.0bf16;
+//CHECK:      VarDecl {{.*}} d_val_2 'double' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+double d_val_3 = 1.0f;
+//CHECK:      VarDecl {{.*}} d_val_3 'double' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'float' 1.000000e+00
+double d_val_4 = 1.0l;
+//CHECK:      VarDecl {{.*}} d_val_4 'double' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'long double' 1.000000e+00
+double d_val_5 = 1.0;
+//CHECK:      VarDecl {{.*}} d_val_5 'double' cinit
+//CHECK-NEXT: FloatingLiteral {{.*}} 'double' 1.000000e+00
+
+long double ld_val_1 = 1.0f16;
+//CHECK:      VarDecl {{.*}} ld_val_1 'long double' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+long double ld_val_2 = 1.0bf16;
+//CHECK:      VarDecl {{.*}} ld_val_2 'long double' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+long double ld_val_3 = 1.0f;
+//CHECK:      VarDecl {{.*}} ld_val_3 'long double' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'float' 1.000000e+00
+long double ld_val_4 = 1.0;
+//CHECK:      VarDecl {{.*}} ld_val_4 'long double' cinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} 'double' 1.000000e+00
+long double ld_val_5 = 1.0l;
+//CHECK:      VarDecl {{.*}} ld_val_5 'long double' cinit
+//CHECK-NEXT: FloatingLiteral {{.*}} 'long double' 1.000000e+00
+
+auto f16_bf16 = 1.0f16 + 1.0bf16; // expected-error {{invalid operands to binary expression ('_Float16' and '__bf16')}}
+auto f16_bf16_cast = 1.0f16 + static_cast<_Float16>(1.0bf16); // expected-error {{static_cast from '__bf16' to '_Float16' is not allowed}}
+auto f16_float = 1.0f16 + 1.0f;
+//CHECK:      VarDecl {{.*}} f16_float 'float':'float' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} 'float' '+'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: FloatingLiteral {{.*}} 'float' 1.000000e+00
+auto f16_double = 1.0f16 + 1.0;
+//CHECK:      VarDecl {{.*}} f16_double 'double':'double' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} 'double' '+'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: FloatingLiteral {{.*}} 'double' 1.000000e+00
+auto f16_ldouble = 1.0f16 + 1.0l;
+//CHECK:      VarDecl {{.*}} f16_ldouble 'long double':'long double' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} 'long double' '+'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: FloatingLiteral {{.*}} 'long double' 1.000000e+00
+auto f16_int = 1.0f16 + 1;
+//CHECK:      VarDecl {{.*}} f16_int '_Float16':'_Float16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '_Float16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'int' 1
+auto f16_uint = 1.0f16 + 1u;
+//CHECK:      VarDecl {{.*}} f16_uint '_Float16':'_Float16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '_Float16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'unsigned int' 1
+auto f16_long = 1.0f16 + 1l;
+//CHECK:      VarDecl {{.*}} f16_long '_Float16':'_Float16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '_Float16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'long' 1
+auto f16_ulong = 1.0f16 + 1ul;
+//CHECK:      VarDecl {{.*}} f16_ulong '_Float16':'_Float16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '_Float16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'unsigned long' 1
+auto f16_llong = 1.0f16 + 1ll;
+//CHECK:      VarDecl {{.*}} f16_llong '_Float16':'_Float16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '_Float16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'long long' 1
+auto f16_ullong = 1.0f16 + 1ull;
+//CHECK:      VarDecl {{.*}} f16_ullong '_Float16':'_Float16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '_Float16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'unsigned long long' 1
+auto f16_bool = 1.0f16 + true;
+//CHECK:      VarDecl {{.*}} f16_bool '_Float16':'_Float16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '_Float16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '_Float16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <IntegralToFloating>
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int' <IntegralCast>
+//CHECK-NEXT: CXXBoolLiteralExpr {{.*}} 'bool' true
+
+auto bf16_fp16 = 1.0bf16 + 1.0f16; // expected-error {{invalid operands to binary expression ('__bf16' and '_Float16')}}
+auto bf16_fp16_cast = 1.0bf16 + static_cast<decltype(0.0BF16)>(1.0f16); // expected-error {{static_cast from '_Float16' to 'decltype(0.BF16)' (aka '__bf16') is not allowed}}
+auto bf16_float = 1.0bf16 + 1.0f;
+//CHECK:      VarDecl {{.*}} bf16_float 'float':'float' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} 'float' '+'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: FloatingLiteral {{.*}} 'float' 1.000000e+00
+auto bf16_double = 1.0bf16 + 1.0;
+//CHECK:      VarDecl {{.*}} bf16_double 'double':'double' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} 'double' '+'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: FloatingLiteral {{.*}} 'double' 1.000000e+00
+auto bf16_ldouble = 1.0bf16 + 1.0l;
+//CHECK:      VarDecl {{.*}} bf16_ldouble 'long double':'long double' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} 'long double' '+'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: FloatingLiteral {{.*}} 'long double' 1.000000e+00
+auto bf16_int = 1.0bf16 + 1;
+//CHECK:      VarDecl {{.*}} bf16_int '__bf16':'__bf16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '__bf16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '__bf16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'int' 1
+auto bf16_uint = 1.0bf16 + 1u;
+//CHECK:      VarDecl {{.*}} bf16_uint '__bf16':'__bf16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '__bf16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '__bf16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'unsigned int' 1
+auto bf16_long = 1.0bf16 + 1l;
+//CHECK:      VarDecl {{.*}} bf16_long '__bf16':'__bf16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '__bf16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '__bf16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'long' 1
+auto bf16_ulong = 1.0bf16 + 1ul;
+//CHECK:      VarDecl {{.*}} bf16_ulong '__bf16':'__bf16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '__bf16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '__bf16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'unsigned long' 1
+auto bf16_llong = 1.0bf16 + 1ll;
+//CHECK:      VarDecl {{.*}} bf16_llong '__bf16':'__bf16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '__bf16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '__bf16' <IntegralToFloating>
+//CHECK-NEXT:  IntegerLiteral {{.*}} 'long long' 1
+auto bf16_ullong = 1.0bf16 + 1ull;
+//CHECK:      VarDecl {{.*}} bf16_ullong '__bf16':'__bf16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '__bf16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '__bf16' <IntegralToFloating>
+//CHECK-NEXT: IntegerLiteral {{.*}} 'unsigned long long' 1
+auto bf16_bool = 1.0bf16 + true;
+//CHECK:      VarDecl {{.*}} bf16_bool '__bf16':'__bf16' cinit
+//CHECK-NEXT: BinaryOperator {{.*}} '__bf16' '+'
+//CHECK-NEXT: FloatingLiteral {{.*}} '__bf16' 1.000000e+00
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '__bf16' <IntegralToFloating>
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int' <IntegralCast>
+//CHECK-NEXT: CXXBoolLiteralExpr {{.*}} 'bool' true
+
+int f(decltype(0.0BF16)) {}
+int f(_Float16) {}
+int f(float) {}
+int f(double) {}
+int f(long double) {}
+int f(int) {}
+
+decltype(0.0BF16) bf16_val = 1.0bf16;
+_Float16 float16_val = 1.0f16;
+float float_val = 1.0f;
+double double_val = 1.0;
+long double long_double_val = 1.0l;
+int int_val = 1;
+
+int test1 = f(bf16_val); // calls f(decltype(0.BF16))
+//CHECK:      VarDecl {{.*}} test1 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(decltype(0.BF16))' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (decltype(0.BF16))' lvalue Function {{.*}} 'f' 'int (decltype(0.BF16))'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'decltype(0.BF16)':'__bf16' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'decltype(0.BF16)':'__bf16' lvalue Var {{.*}} 'bf16_val' 'decltype(0.BF16)':'__bf16'
+int test2 = f(float16_val); // calls f(_Float16)
+//CHECK:      VarDecl {{.*}} test2 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(_Float16)' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (_Float16)' lvalue Function {{.*}} 'f' 'int (_Float16)'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} '_Float16' lvalue Var {{.*}} 'float16_val' '_Float16'
+int test3 = f(float_val); // calls f(float)
+//CHECK:      VarDecl {{.*}} test3 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(float)' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (float)' lvalue Function {{.*}} 'f' 'int (float)'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'float' lvalue Var {{.*}} 'float_val' 'float'
+int test4 = f(double_val); // calls f(double)
+//CHECK:      VarDecl {{.*}} test4 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(double)' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (double)' lvalue Function {{.*}} 'f' 'int (double)'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'double' lvalue Var {{.*}} 'double_val' 'double'
+int test5 = f(long_double_val); // calls f(long double)
+//CHECK:      VarDecl {{.*}} test5 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(long double)' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (long double)' lvalue Function {{.*}} 'f' 'int (long double)'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'long double' lvalue Var {{.*}} 'long_double_val' 'long double'
+int test6 = f(int_val); // calls f(int)
+//CHECK:      VarDecl {{.*}} test6 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(int)' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (int)' lvalue Function {{.*}} 'f' 'int (int)'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int' lvalue Var {{.*}} 'int_val' 'int'
+
+int f_1(float) {} // expected-note {{candidate function}} expected-note {{candidate function}}
+int f_1(double) {} // expected-note {{candidate function}} expected-note {{candidate function}}
+
+// Ambiguous cases
+int test_7 = f_1(bf16_val); // expected-error {{call to 'f_1' is ambiguous}}
+int test_8 = f_1(float16_val); // expected-error {{call to 'f_1' is ambiguous}}
+
+int f_2(long double) {}
+int test_9 = f_2(float_val);
+//CHECK:      VarDecl {{.*}} test_9 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(long double)' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (long double)' lvalue Function {{.*}} 'f_2' 'int (long double)'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'float' lvalue Var {{.*}} 'float_val' 'float'
+int test_10 = f_2(double_val);
+//CHECK:      VarDecl {{.*}} test_10 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(long double)' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (long double)' lvalue Function {{.*}} 'f_2' 'int (long double)'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'double' lvalue Var {{.*}} 'double_val' 'double'
+int test_11 = f_2(bf16_val);
+//CHECK:      VarDecl {{.*}} test_11 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(long double)' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (long double)' lvalue Function {{.*}} 'f_2' 'int (long double)'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'decltype(0.BF16)':'__bf16' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'decltype(0.BF16)':'__bf16' lvalue Var {{.*}} 'bf16_val' 'decltype(0.BF16)':'__bf16'
+int test_12 = f_2(float16_val);
+//CHECK:      VarDecl {{.*}} test_12 'int' cinit
+//CHECK-NEXT: CallExpr {{.*}} 'int'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int (*)(long double)' <FunctionToPointerDecay>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'int (long double)' lvalue Function {{.*}} 'f_2' 'int (long double)'
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <FloatingCast>
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <LValueToRValue>
+//CHECK-NEXT: DeclRefExpr {{.*}} '_Float16' lvalue Var {{.*}} 'float16_val' '_Float16'
+
+int f_3(_Float16) {} // expected-note {{candidate function not viable: no known conversion from 'float' to '_Float16' for 1st argument}} expected-note {{no known conversion from 'decltype(0.BF16)' (aka '__bf16') to '_Float16' for 1st argument}}
+int test_13 = f_3(float_val); // expected-error {{no matching function for call to 'f_3'}}
+int test_14 = f_3(bf16_val); // expected-error {{no matching function for call to 'f_3'}}
+int test_15 = f_3(static_cast<_Float16>(bf16_val)); // expected-error {{static_cast from 'decltype(0.BF16)' (aka '__bf16') to '_Float16' is not allowed}}
+
+int f_4(decltype(0.0BF16)) {} // expected-note {{candidate function not viable: no known conversion from 'float' to 'decltype(0.BF16)' (aka '__bf16') for 1st argument}} expected-note {{candidate function not viable: no known conversion from '_Float16' to 'decltype(0.BF16)' (aka '__bf16') for 1st argument}}
+int test_16 = f_4(float_val); // expected-error {{no matching function for call to 'f_4'}}
+int test_17 = f_4(float16_val); // expected-error {{no matching function for call to 'f_4'}}
+int test_18 = f_4(static_cast<decltype(0.0BF16)>(float16_val)); // expected-error {{static_cast from '_Float16' to 'decltype(0.BF16)' (aka '__bf16') is not allowed}}
+
+struct S {
+  operator decltype(0.0BF16)() const {
+      return 0.0bf16;
+  }
+  operator _Float16() const {
+      return 0.0f16;
+  }
+  operator float() const {
+      return 0.0f;
+  }
+  operator double() const {
+      return 0.0;
+  }
+  operator long double() const {
+      return 0.0L;
+  }
+  operator int() const {
+      return 0;
+  }
+};
+
+
+S user_defined_val;
+// User-defined overload cases
+decltype(0.0BF16) bfloat16_val(user_defined_val); // calls operator decltype(0.BF16)()
+//CHECK:      VarDecl {{.*}} bfloat16_val 'decltype(0.BF16)':'__bf16' callinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'decltype(0.BF16)':'__bf16' <UserDefinedConversion>
+//CHECK-NEXT: CXXMemberCallExpr {{.*}} 'decltype(0.BF16)':'__bf16'
+//CHECK-NEXT: MemberExpr {{.*}} '<bound member function type>' .operator __bf16 {{.*}}
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'const S' lvalue <NoOp>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'S':'S' lvalue Var {{.*}} 'user_defined_val' 'S':'S'
+_Float16 f16_val(user_defined_val); // calls operator _Float16()
+//CHECK:      VarDecl {{.*}} f16_val '_Float16' callinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} '_Float16' <UserDefinedConversion>
+//CHECK-NEXT: CXXMemberCallExpr {{.*}} '_Float16
+//CHECK-NEXT: MemberExpr {{.*}} '<bound member function type>' .operator _Float16 {{.*}}
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'const S' lvalue <NoOp>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'S':'S' lvalue Var {{.*}} 'user_defined_val' 'S':'S'
+float f_val(user_defined_val); // calls operator float()
+//CHECK:      VarDecl {{.*}} f_val 'float' callinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <UserDefinedConversion>
+//CHECK-NEXT: CXXMemberCallExpr {{.*}} 'float'
+//CHECK-NEXT: MemberExpr {{.*}} '<bound member function type>' .operator float {{.*}}
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'const S' lvalue <NoOp>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'S':'S' lvalue Var {{.*}} 'user_defined_val' 'S':'S'
+double d_val(user_defined_val); // calls operator double()
+//CHECK:      VarDecl {{.*}} d_val 'double' callinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'double' <UserDefinedConversion>
+//CHECK-NEXT: CXXMemberCallExpr {{.*}} 'double'
+//CHECK-NEXT: MemberExpr {{.*}} '<bound member function type>' .operator double {{.*}}
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'const S' lvalue <NoOp>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'S':'S' lvalue Var {{.*}} 'user_defined_val' 'S':'S'
+long double ld_val(user_defined_val); // calls operator long double()
+//CHECK:      VarDecl {{.*}} ld_val 'long double' callinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'long double' <UserDefinedConversion>
+//CHECK-NEXT: CXXMemberCallExpr {{.*}} 'long double'
+//CHECK-NEXT: MemberExpr {{.*}} '<bound member function type>' .operator long double {{.*}}
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'const S' lvalue <NoOp>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'S':'S' lvalue Var {{.*}} 'user_defined_val' 'S':'S'
+int i_val(user_defined_val); // calls operator int()
+//CHECK:      VarDecl {{.*}} i_val 'int' callinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int' <UserDefinedConversion>
+//CHECK-NEXT: CXXMemberCallExpr {{.*}} 'int'
+//CHECK-NEXT: MemberExpr {{.*}} '<bound member function type>' .operator int {{.*}}
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'const S' lvalue <NoOp>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'S':'S' lvalue Var {{.*}} 'user_defined_val' 'S':'S'
+struct S1 {
+  operator _Float16() const {
+      return 0.0f16;
+  }
+  operator float() const {
+      return 0.0f;
+  }
+  operator double() const {
+      return 0.0;
+  }
+  operator long double() const {
+      return 0.0L;
+  }
+  operator int() const {
+      return 0;
+  }
+};
+
+S1 user_defined_val_2;
+// User-defined overload cases
+decltype(0.0BF16) bfloat16_val_2(user_defined_val_2); // calls operator int()
+//CHECK:      VarDecl {{.*}} bfloat16_val_2 'decltype(0.BF16)':'__bf16' callinit
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'decltype(0.BF16)':'__bf16' <IntegralToFloating>
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'int' <UserDefinedConversion>
+//CHECK-NEXT: CXXMemberCallExpr {{.*}} 'int'
+//CHECK-NEXT: MemberExpr {{.*}} '<bound member function type>' .operator int {{.*}}
+//CHECK-NEXT: ImplicitCastExpr {{.*}} 'const S1' lvalue <NoOp>
+//CHECK-NEXT: DeclRefExpr {{.*}} 'S1':'S1' lvalue Var {{.*}} 'user_defined_val_2' 'S1':'S1'
+struct S2 {
+  operator decltype(0.0BF16)() const { // expected-note {{candidate function}}
+      return 0.0bf16;
+  }
+
+  operator _Float16() const { // expected-note {{candidate function}}
+      return 0.0f16;
+  }
+  operator double() const { // expected-note {{candidate function}}
+      return 0.0;
+  }
+  operator long double() const { // expected-note {{candidate function}}
+      return 0.0L;
+  }
+  operator int() const { // expected-note {{candidate function}}
+      return 0;
+  }
+};
+
+S2 user_defined_val_3;
+// User-defined overload cases
+float float_val_2(user_defined_val_3); // expected-error {{conversion from 'S2' to 'float' is ambiguous}}