diff --git a/clang/include/clang/Basic/OpenACCKinds.h b/clang/include/clang/Basic/OpenACCKinds.h
@@ -72,25 +72,42 @@ enum class OpenACCAtomicKind {
 
 /// Represents the kind of an OpenACC clause.
 enum class OpenACCClauseKind {
-  // 'finalize' clause, allowed on 'exit data' directive.
+  /// 'finalize' clause, allowed on 'exit data' directive.
   Finalize,
-  // 'if_present' clause, allowed on 'host_data' and 'update' directives.
+  /// 'if_present' clause, allowed on 'host_data' and 'update' directives.
   IfPresent,
-  // 'seq' clause, allowed on 'loop' and 'routine' directives.
+  /// 'seq' clause, allowed on 'loop' and 'routine' directives.
   Seq,
-  // 'independent' clause, allowed on 'loop' directives.
+  /// 'independent' clause, allowed on 'loop' directives.
   Independent,
-  // 'auto' clause, allowed on 'loop' directives.
+  /// 'auto' clause, allowed on 'loop' directives.
   Auto,
-  // 'worker' clause, allowed on 'loop' and 'routine' directives.
+  /// 'worker' clause, allowed on 'loop' and 'routine' directives.
   Worker,
-  // 'vector' clause, allowed on 'loop' and 'routine' directives. Takes no
-  // arguments for 'routine', so the 'loop' version is not yet implemented
-  // completely.
+  /// 'vector' clause, allowed on 'loop' and 'routine' directives. Takes no
+  /// arguments for 'routine', so the 'loop' version is not yet implemented
+  /// completely.
   Vector,
-  // 'nohost' clause, allowed on 'routine' directives.
+  /// 'nohost' clause, allowed on 'routine' directives.
   NoHost,
-  // Represents an invalid clause, for the purposes of parsing.
+  /// 'default' clause, allowed on parallel, serial, kernel (and compound)
+  /// constructs.
+  Default,
+  /// 'if' clause, allowed on all the Compute Constructs, Data Constructs,
+  /// Executable Constructs, and Combined Constructs.
+  If,
+  /// 'self' clause, allowed on Compute and Combined Constructs, plus 'update'.
+  Self,
+  /// Represents an invalid clause, for the purposes of parsing.
+  Invalid,
+};
+
+enum class OpenACCDefaultClauseKind {
+  /// 'none' option.
+  None,
+  /// 'present' option.
+  Present,
+  /// Not a valid option.
   Invalid,
 };
 } // namespace clang

diff --git a/clang/include/clang/Basic/arm_sve.td b/clang/include/clang/Basic/arm_sve.td
diff --git a/clang/include/clang/Basic/arm_sve_sme_incl.td b/clang/include/clang/Basic/arm_sve_sme_incl.td
@@ -227,6 +227,7 @@ def IsPreservesZA             : FlagType<0x10000000000>;
 def IsReadZA                  : FlagType<0x20000000000>;
 def IsWriteZA                 : FlagType<0x40000000000>;
 def IsReductionQV             : FlagType<0x80000000000>;
+def IsStreamingOrSVE2p1       : FlagType<0x80000000000>; // Use for intrinsics that are common between sme/sme2 and sve2p1.
 
 // These must be kept in sync with the flags in include/clang/Basic/TargetBuiltins.h
 class ImmCheckType<int val> {

diff --git a/clang/include/clang/Basic/riscv_sifive_vector.td b/clang/include/clang/Basic/riscv_sifive_vector.td
@@ -121,11 +121,11 @@ multiclass RVVVQMACCDODBuiltinSet<list<list<string>> suffixes_prototypes> {
 }
 
 multiclass RVVVQMACCQOQBuiltinSet<list<list<string>> suffixes_prototypes> {
-   let OverloadedName = NAME,
-       Name = NAME,
-       HasMasked = false,
-       Log2LMUL = [-1, 0, 1, 2] in
-     defm NAME : RVVOutOp1Op2BuiltinSet<NAME, "s", suffixes_prototypes>;
+  let OverloadedName = NAME,
+      Name = NAME,
+      HasMasked = false,
+      Log2LMUL = [-1, 0, 1, 2] in
+    defm NAME : RVVOutOp1Op2BuiltinSet<NAME, "s", suffixes_prototypes>;
 }
 
 multiclass RVVVFNRCLIPBuiltinSet<string suffix, string prototype, string type_range> {

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -773,6 +773,8 @@ def gcc_install_dir_EQ : Joined<["--"], "gcc-install-dir=">,
 def gcc_toolchain : Joined<["--"], "gcc-toolchain=">, Flags<[NoXarchOption]>,
   HelpText<"Specify a directory where Clang can find 'include' and 'lib{,32,64}/gcc{,-cross}/$triple/$version'. "
   "Clang will use the GCC installation with the largest version">;
+def gcc_triple_EQ : Joined<["--"], "gcc-triple=">,
+  HelpText<"Search for the GCC installation with the specified triple.">;
 def CC : Flag<["-"], "CC">, Visibility<[ClangOption, CC1Option]>,
   Group<Preprocessor_Group>,
     HelpText<"Include comments from within macros in preprocessed output">,
@@ -1695,6 +1697,12 @@ defm coverage_mapping : BoolFOption<"coverage-mapping",
           "Generate coverage mapping to enable code coverage analysis">,
   NegFlag<SetFalse, [], [ClangOption], "Disable code coverage analysis">, BothFlags<
           [], [ClangOption, CLOption]>>;
+defm mcdc_coverage : BoolFOption<"coverage-mcdc",
+  CodeGenOpts<"MCDCCoverage">, DefaultFalse,
+  PosFlag<SetTrue, [], [ClangOption, CC1Option],
+          "Enable MC/DC criteria when generating code coverage">,
+  NegFlag<SetFalse, [], [ClangOption], "Disable MC/DC coverage criteria">,
+          BothFlags<[], [ClangOption, CLOption]>>;
 def fprofile_generate : Flag<["-"], "fprofile-generate">,
     Group<f_Group>, Visibility<[ClangOption, CLOption]>,
     HelpText<"Generate instrumented code to collect execution counts into default.profraw (overridden by LLVM_PROFILE_FILE env var)">;
@@ -4577,11 +4585,13 @@ let Flags = [TargetSpecific] in {
 def menable_experimental_extensions : Flag<["-"], "menable-experimental-extensions">, Group<m_Group>,
   HelpText<"Enable use of experimental RISC-V extensions.">;
 def mrvv_vector_bits_EQ : Joined<["-"], "mrvv-vector-bits=">, Group<m_Group>,
-  HelpText<"Specify the size in bits of an RVV vector register. Defaults to "
-           "the vector length agnostic value of \"scalable\". Accepts power of "
-           "2 values between 64 and 65536. Also accepts \"zvl\" "
-           "to use the value implied by -march/-mcpu. Value will be reflected "
-           "in __riscv_v_fixed_vlen preprocessor define (RISC-V only)">;
+  Visibility<[ClangOption, FlangOption]>,
+  HelpText<"Specify the size in bits of an RVV vector register">,
+  DocBrief<"Defaults to the vector length agnostic value of \"scalable\". "
+           "Accepts power of 2 values between 64 and 65536. Also accepts "
+           "\"zvl\" to use the value implied by -march/-mcpu. On Clang, value "
+           "will be reflected in __riscv_v_fixed_vlen preprocessor define "
+           "(RISC-V only)">;
 
 def munaligned_access : Flag<["-"], "munaligned-access">, Group<m_Group>,
   HelpText<"Allow memory accesses to be unaligned (AArch32/AArch64/LoongArch/RISC-V only)">;
@@ -5189,12 +5199,12 @@ def nohipwrapperinc : Flag<["-"], "nohipwrapperinc">, Group<IncludePath_Group>,
   HelpText<"Do not include the default HIP wrapper headers and include paths">;
 def : Flag<["-"], "nocudainc">, Alias<nogpuinc>;
 def nogpulib : Flag<["-"], "nogpulib">, MarshallingInfoFlag<LangOpts<"NoGPULib">>,
-  Visibility<[ClangOption, CC1Option]>,
+  Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
   HelpText<"Do not link device library for CUDA/HIP device compilation">;
 def : Flag<["-"], "nocudalib">, Alias<nogpulib>;
-def gpulibc : Flag<["-"], "gpulibc">, Visibility<[ClangOption, CC1Option]>,
+def gpulibc : Flag<["-"], "gpulibc">, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
   HelpText<"Link the LLVM C Library for GPUs">;
-def nogpulibc : Flag<["-"], "nogpulibc">, Visibility<[ClangOption, CC1Option]>;
+def nogpulibc : Flag<["-"], "nogpulibc">, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>;
 def nodefaultlibs : Flag<["-"], "nodefaultlibs">;
 def nodriverkitlib : Flag<["-"], "nodriverkitlib">;
 def nofixprebinding : Flag<["-"], "nofixprebinding">;

diff --git a/clang/include/clang/Format/.clang-format b/clang/include/clang/Format/.clang-format
@@ -1 +1,6 @@
-BasedOnStyle: clang-format
+BasedOnStyle: LLVM
+InsertBraces: true
+InsertNewlineAtEOF: true
+LineEnding: LF
+RemoveBracesLLVM: true
+RemoveParentheses: ReturnStatement
diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
@@ -234,6 +234,26 @@ class Parser : public CodeCompletionHandler {
   /// Parsing OpenACC directive mode.
   bool OpenACCDirectiveParsing = false;
 
+  /// Currently parsing a situation where an OpenACC array section could be
+  /// legal, such as a 'var-list'.
+  bool AllowOpenACCArraySections = false;
+
+  /// RAII object to set reset OpenACC parsing a context where Array Sections
+  /// are allowed.
+  class OpenACCArraySectionRAII {
+    Parser &P;
+
+  public:
+    OpenACCArraySectionRAII(Parser &P) : P(P) {
+      assert(!P.AllowOpenACCArraySections);
+      P.AllowOpenACCArraySections = true;
+    }
+    ~OpenACCArraySectionRAII() {
+      assert(P.AllowOpenACCArraySections);
+      P.AllowOpenACCArraySections = false;
+    }
+  };
+
   /// When true, we are directly inside an Objective-C message
   /// send expression.
   ///
@@ -3546,8 +3566,8 @@ class Parser : public CodeCompletionHandler {
   ExprResult ParseOpenACCIDExpression();
   /// Parses the variable list for the `cache` construct.
   void ParseOpenACCCacheVarList();
-  /// Parses a single variable in a variable list for the 'cache' construct.
-  bool ParseOpenACCCacheVar();
+  /// Parses a single variable in a variable list for OpenACC.
+  bool ParseOpenACCVar();
   bool ParseOpenACCWaitArgument();
 
 private:

diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
@@ -10263,11 +10263,13 @@ class Sema final {
     ~ConstraintEvalRAII() { TI.setEvaluateConstraints(OldValue); }
   };
 
-  // Unlike the above, this evaluates constraints, which should only happen at
-  // 'constraint checking' time.
+  // Must be used instead of SubstExpr at 'constraint checking' time.
   ExprResult
   SubstConstraintExpr(Expr *E,
                       const MultiLevelTemplateArgumentList &TemplateArgs);
+  // Unlike the above, this does not evaluates constraints.
+  ExprResult SubstConstraintExprWithoutSatisfaction(
+      Expr *E, const MultiLevelTemplateArgumentList &TemplateArgs);
 
   /// Substitute the given template arguments into a list of
   /// expressions, expanding pack expansions if required.
@@ -11344,9 +11346,12 @@ class Sema final {
   /// rigorous semantic checking in the new mapped directives.
   bool mapLoopConstruct(llvm::SmallVector<OMPClause *> &ClausesWithoutBind,
                         ArrayRef<OMPClause *> Clauses,
-                        OpenMPBindClauseKind BindKind,
+                        OpenMPBindClauseKind &BindKind,
                         OpenMPDirectiveKind &Kind,
-                        OpenMPDirectiveKind &PrevMappedDirective);
+                        OpenMPDirectiveKind &PrevMappedDirective,
+                        SourceLocation StartLoc, SourceLocation EndLoc,
+                        const DeclarationNameInfo &DirName,
+                        OpenMPDirectiveKind CancelRegion);
 
 public:
   /// The declarator \p D defines a function in the scope \p S which is nested
@@ -12967,7 +12972,7 @@ class Sema final {
   QualType FindCompositeObjCPointerType(ExprResult &LHS, ExprResult &RHS,
                                         SourceLocation QuestionLoc);
 
-  bool DiagnoseConditionalForNull(Expr *LHSExpr, Expr *RHSExpr,
+  bool DiagnoseConditionalForNull(const Expr *LHSExpr, const Expr *RHSExpr,
                                   SourceLocation QuestionLoc);
 
   void DiagnoseAlwaysNonNullPointer(Expr *E,

diff --git a/clang/include/clang/Sema/Template.h b/clang/include/clang/Sema/Template.h
@@ -564,6 +564,7 @@ enum class TemplateSubstitutionKind : char {
     const MultiLevelTemplateArgumentList &TemplateArgs;
     Sema::LateInstantiatedAttrVec* LateAttrs = nullptr;
     LocalInstantiationScope *StartingScope = nullptr;
+    // Whether to evaluate the C++20 constraints or simply substitute into them.
     bool EvaluateConstraints = true;
 
     /// A list of out-of-line class template partial

diff --git a/clang/include/clang/StaticAnalyzer/Core/BugReporter/CommonBugCategories.h b/clang/include/clang/StaticAnalyzer/Core/BugReporter/CommonBugCategories.h
@@ -13,6 +13,7 @@
 namespace clang {
 namespace ento {
 namespace categories {
+extern const char *const AppleAPIMisuse;
 extern const char *const CoreFoundationObjectiveC;
 extern const char *const LogicError;
 extern const char *const MemoryRefCount;

diff --git a/clang/include/clang/StaticAnalyzer/Core/Checker.h b/clang/include/clang/StaticAnalyzer/Core/Checker.h
@@ -193,9 +193,8 @@ class PostCall {
 
 class Location {
   template <typename CHECKER>
-  static void _checkLocation(void *checker,
-                             const SVal &location, bool isLoad, const Stmt *S,
-                             CheckerContext &C) {
+  static void _checkLocation(void *checker, SVal location, bool isLoad,
+                             const Stmt *S, CheckerContext &C) {
     ((const CHECKER *)checker)->checkLocation(location, isLoad, S, C);
   }
 
@@ -209,8 +208,7 @@ class Location {
 
 class Bind {
   template <typename CHECKER>
-  static void _checkBind(void *checker,
-                         const SVal &location, const SVal &val, const Stmt *S,
+  static void _checkBind(void *checker, SVal location, SVal val, const Stmt *S,
                          CheckerContext &C) {
     ((const CHECKER *)checker)->checkBind(location, val, S, C);
   }
@@ -456,10 +454,8 @@ namespace eval {
 
 class Assume {
   template <typename CHECKER>
-  static ProgramStateRef _evalAssume(void *checker,
-                                         ProgramStateRef state,
-                                         const SVal &cond,
-                                         bool assumption) {
+  static ProgramStateRef _evalAssume(void *checker, ProgramStateRef state,
+                                     SVal cond, bool assumption) {
     return ((const CHECKER *)checker)->evalAssume(state, cond, assumption);
   }
 

diff --git a/clang/include/clang/StaticAnalyzer/Core/CheckerManager.h b/clang/include/clang/StaticAnalyzer/Core/CheckerManager.h
@@ -488,13 +488,11 @@ class CheckerManager {
   using CheckCallFunc =
       CheckerFn<void (const CallEvent &, CheckerContext &)>;
 
-  using CheckLocationFunc =
-      CheckerFn<void (const SVal &location, bool isLoad, const Stmt *S,
-                      CheckerContext &)>;
+  using CheckLocationFunc = CheckerFn<void(SVal location, bool isLoad,
+                                           const Stmt *S, CheckerContext &)>;
 
   using CheckBindFunc =
-      CheckerFn<void (const SVal &location, const SVal &val, const Stmt *S,
-                      CheckerContext &)>;
+      CheckerFn<void(SVal location, SVal val, const Stmt *S, CheckerContext &)>;
 
   using CheckEndAnalysisFunc =
       CheckerFn<void (ExplodedGraph &, BugReporter &, ExprEngine &)>;
@@ -530,8 +528,7 @@ class CheckerManager {
                                  RegionAndSymbolInvalidationTraits *ITraits)>;
 
   using EvalAssumeFunc =
-      CheckerFn<ProgramStateRef (ProgramStateRef, const SVal &cond,
-                                 bool assumption)>;
+      CheckerFn<ProgramStateRef(ProgramStateRef, SVal cond, bool assumption)>;
 
   using EvalCallFunc = CheckerFn<bool (const CallEvent &, CheckerContext &)>;
 

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
@@ -1318,6 +1318,13 @@ void ASTContext::InitBuiltinTypes(const TargetInfo &Target,
     InitBuiltinType(OMPArrayShapingTy, BuiltinType::OMPArrayShaping);
     InitBuiltinType(OMPIteratorTy, BuiltinType::OMPIterator);
   }
+  // Placeholder type for OpenACC array sections.
+  if (LangOpts.OpenACC) {
+    // FIXME: Once we implement OpenACC array sections in Sema, this will either
+    // be combined with the OpenMP type, or given its own type. In the meantime,
+    // just use the OpenMP type so that parsing can work.
+    InitBuiltinType(OMPArraySectionTy, BuiltinType::OMPArraySection);
+  }
   if (LangOpts.MatrixTypes)
     InitBuiltinType(IncompleteMatrixIdxTy, BuiltinType::IncompleteMatrixIdx);
 
@@ -2748,21 +2755,20 @@ bool ASTContext::hasUniqueObjectRepresentations(
     QualType Ty, bool CheckIfTriviallyCopyable) const {
   // C++17 [meta.unary.prop]:
   //   The predicate condition for a template specialization
-  //   has_unique_object_representations<T> shall be
-  //   satisfied if and only if:
+  //   has_unique_object_representations<T> shall be satisfied if and only if:
   //     (9.1) - T is trivially copyable, and
   //     (9.2) - any two objects of type T with the same value have the same
-  //     object representation, where two objects
-  //   of array or non-union class type are considered to have the same value
-  //   if their respective sequences of
-  //   direct subobjects have the same values, and two objects of union type
-  //   are considered to have the same
-  //   value if they have the same active member and the corresponding members
-  //   have the same value.
+  //     object representation, where:
+  //     - two objects of array or non-union class type are considered to have
+  //       the same value if their respective sequences of direct subobjects
+  //       have the same values, and
+  //     - two objects of union type are considered to have the same value if
+  //       they have the same active member and the corresponding members have
+  //       the same value.
   //   The set of scalar types for which this condition holds is
-  //   implementation-defined. [ Note: If a type has padding
-  //   bits, the condition does not hold; otherwise, the condition holds true
-  //   for unsigned integral types. -- end note ]
+  //   implementation-defined. [ Note: If a type has padding bits, the condition
+  //   does not hold; otherwise, the condition holds true for unsigned integral
+  //   types. -- end note ]
   assert(!Ty.isNull() && "Null QualType sent to unique object rep check");
 
   // Arrays are unique only if their element type is unique.

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
@@ -2034,23 +2034,25 @@ ASTNodeImporter::ImportDeclContext(DeclContext *FromDC, bool ForceImport) {
     return ToDCOrErr.takeError();
   }
 
-  DeclContext *ToDC = *ToDCOrErr;
-  // Remove all declarations, which may be in wrong order in the
-  // lexical DeclContext and then add them in the proper order.
-  for (auto *D : FromDC->decls()) {
-    if (!MightNeedReordering(D))
-      continue;
+  if (const auto *FromRD = dyn_cast<RecordDecl>(FromDC)) {
+    DeclContext *ToDC = *ToDCOrErr;
+    // Remove all declarations, which may be in wrong order in the
+    // lexical DeclContext and then add them in the proper order.
+    for (auto *D : FromRD->decls()) {
+      if (!MightNeedReordering(D))
+        continue;
 
-    assert(D && "DC contains a null decl");
-    if (Decl *ToD = Importer.GetAlreadyImportedOrNull(D)) {
-      // Remove only the decls which we successfully imported.
-      assert(ToDC == ToD->getLexicalDeclContext() && ToDC->containsDecl(ToD));
-      // Remove the decl from its wrong place in the linked list.
-      ToDC->removeDecl(ToD);
-      // Add the decl to the end of the linked list.
-      // This time it will be at the proper place because the enclosing for
-      // loop iterates in the original (good) order of the decls.
-      ToDC->addDeclInternal(ToD);
+      assert(D && "DC contains a null decl");
+      if (Decl *ToD = Importer.GetAlreadyImportedOrNull(D)) {
+        // Remove only the decls which we successfully imported.
+        assert(ToDC == ToD->getLexicalDeclContext() && ToDC->containsDecl(ToD));
+        // Remove the decl from its wrong place in the linked list.
+        ToDC->removeDecl(ToD);
+        // Add the decl to the end of the linked list.
+        // This time it will be at the proper place because the enclosing for
+        // loop iterates in the original (good) order of the decls.
+        ToDC->addDeclInternal(ToD);
+      }
     }
   }
 
@@ -6141,6 +6143,11 @@ ExpectedDecl ASTNodeImporter::VisitClassTemplateSpecializationDecl(
                                                   InsertPos))
       // Add this partial specialization to the class template.
       ClassTemplate->AddPartialSpecialization(PartSpec2, InsertPos);
+    if (Expected<ClassTemplatePartialSpecializationDecl *> ToInstOrErr =
+            import(PartialSpec->getInstantiatedFromMember()))
+      PartSpec2->setInstantiatedFromMember(*ToInstOrErr);
+    else
+      return ToInstOrErr.takeError();
 
     updateLookupTableForTemplateParameters(*ToTPList);
   } else { // Not a partial specialization.

diff --git a/clang/lib/AST/ASTStructuralEquivalence.cpp b/clang/lib/AST/ASTStructuralEquivalence.cpp
@@ -1463,8 +1463,9 @@ IsStructurallyEquivalentLambdas(StructuralEquivalenceContext &Context,
 }
 
 /// Determine if context of a class is equivalent.
-static bool IsRecordContextStructurallyEquivalent(RecordDecl *D1,
-                                                  RecordDecl *D2) {
+static bool
+IsRecordContextStructurallyEquivalent(StructuralEquivalenceContext &Context,
+                                      RecordDecl *D1, RecordDecl *D2) {
   // The context should be completely equal, including anonymous and inline
   // namespaces.
   // We compare objects as part of full translation units, not subtrees of
@@ -1491,6 +1492,12 @@ static bool IsRecordContextStructurallyEquivalent(RecordDecl *D1,
         return false;
     }
 
+    if (auto *D1Spec = dyn_cast<ClassTemplateSpecializationDecl>(DC1)) {
+      auto *D2Spec = dyn_cast<ClassTemplateSpecializationDecl>(DC2);
+      if (!IsStructurallyEquivalent(Context, D1Spec, D2Spec))
+        return false;
+    }
+
     DC1 = DC1->getParent()->getNonTransparentContext();
     DC2 = DC2->getParent()->getNonTransparentContext();
   }
@@ -1544,7 +1551,7 @@ static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
   // If the records occur in different context (namespace), these should be
   // different. This is specially important if the definition of one or both
   // records is missing.
-  if (!IsRecordContextStructurallyEquivalent(D1, D2))
+  if (!IsRecordContextStructurallyEquivalent(Context, D1, D2))
     return false;
 
   // If both declarations are class template specializations, we know

diff --git a/clang/lib/AST/ComputeDependence.cpp b/clang/lib/AST/ComputeDependence.cpp
@@ -603,6 +603,8 @@ ExprDependence clang::computeDependence(PredefinedExpr *E) {
 ExprDependence clang::computeDependence(CallExpr *E,
                                         llvm::ArrayRef<Expr *> PreArgs) {
   auto D = E->getCallee()->getDependence();
+  if (E->getType()->isDependentType())
+    D |= ExprDependence::Type;
   for (auto *A : llvm::ArrayRef(E->getArgs(), E->getNumArgs())) {
     if (A)
       D |= A->getDependence();

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
@@ -2835,7 +2835,7 @@ CharUnits VarDecl::getFlexibleArrayInitChars(const ASTContext &Ctx) const {
   if (!Ty || !Ty->getDecl()->hasFlexibleArrayMember())
     return CharUnits::Zero();
   auto *List = dyn_cast<InitListExpr>(getInit()->IgnoreParens());
-  if (!List)
+  if (!List || List->getNumInits() == 0)
     return CharUnits::Zero();
   const Expr *FlexibleInit = List->getInit(List->getNumInits() - 1);
   auto InitTy = Ctx.getAsConstantArrayType(FlexibleInit->getType());

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
@@ -930,39 +930,27 @@ const AttrVec &Decl::getAttrs() const {
 
 Decl *Decl::castFromDeclContext (const DeclContext *D) {
   Decl::Kind DK = D->getDeclKind();
-  switch(DK) {
-#define DECL(NAME, BASE)
-#define DECL_CONTEXT(NAME) \
-    case Decl::NAME:       \
-      return static_cast<NAME##Decl *>(const_cast<DeclContext *>(D));
-#define DECL_CONTEXT_BASE(NAME)
-#include "clang/AST/DeclNodes.inc"
-    default:
+  switch (DK) {
 #define DECL(NAME, BASE)
-#define DECL_CONTEXT_BASE(NAME)                  \
-      if (DK >= first##NAME && DK <= last##NAME) \
-        return static_cast<NAME##Decl *>(const_cast<DeclContext *>(D));
+#define DECL_CONTEXT(NAME)                                                     \
+  case Decl::NAME:                                                             \
+    return static_cast<NAME##Decl *>(const_cast<DeclContext *>(D));
 #include "clang/AST/DeclNodes.inc"
-      llvm_unreachable("a decl that inherits DeclContext isn't handled");
+  default:
+    llvm_unreachable("a decl that inherits DeclContext isn't handled");
   }
 }
 
 DeclContext *Decl::castToDeclContext(const Decl *D) {
   Decl::Kind DK = D->getKind();
   switch(DK) {
 #define DECL(NAME, BASE)
-#define DECL_CONTEXT(NAME) \
-    case Decl::NAME:       \
-      return static_cast<NAME##Decl *>(const_cast<Decl *>(D));
-#define DECL_CONTEXT_BASE(NAME)
+#define DECL_CONTEXT(NAME)                                                     \
+  case Decl::NAME:                                                             \
+    return static_cast<NAME##Decl *>(const_cast<Decl *>(D));
 #include "clang/AST/DeclNodes.inc"
-    default:
-#define DECL(NAME, BASE)
-#define DECL_CONTEXT_BASE(NAME)                                   \
-      if (DK >= first##NAME && DK <= last##NAME)                  \
-        return static_cast<NAME##Decl *>(const_cast<Decl *>(D));
-#include "clang/AST/DeclNodes.inc"
-      llvm_unreachable("a decl that inherits DeclContext isn't handled");
+  default:
+    llvm_unreachable("a decl that inherits DeclContext isn't handled");
   }
 }
 
@@ -1129,20 +1117,14 @@ DeclContext::DeclContext(Decl::Kind K) {
 }
 
 bool DeclContext::classof(const Decl *D) {
-  switch (D->getKind()) {
+  Decl::Kind DK = D->getKind();
+  switch (DK) {
 #define DECL(NAME, BASE)
 #define DECL_CONTEXT(NAME) case Decl::NAME:
-#define DECL_CONTEXT_BASE(NAME)
 #include "clang/AST/DeclNodes.inc"
-      return true;
-    default:
-#define DECL(NAME, BASE)
-#define DECL_CONTEXT_BASE(NAME)                 \
-      if (D->getKind() >= Decl::first##NAME &&  \
-          D->getKind() <= Decl::last##NAME)     \
-        return true;
-#include "clang/AST/DeclNodes.inc"
-      return false;
+    return true;
+  default:
+    return false;
   }
 }
 

diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
@@ -587,6 +587,19 @@ bool CXXRecordDecl::isTriviallyCopyable() const {
   return true;
 }
 
+bool CXXRecordDecl::isTriviallyCopyConstructible() const {
+
+  //   A trivially copy constructible class is a class that:
+  //   -- has no non-trivial copy constructors,
+  if (hasNonTrivialCopyConstructor())
+    return false;
+  //   -- has a trivial destructor.
+  if (!hasTrivialDestructor())
+    return false;
+
+  return true;
+}
+
 void CXXRecordDecl::markedVirtualFunctionPure() {
   // C++ [class.abstract]p2:
   //   A class is abstract if it has at least one pure virtual function.

diff --git a/clang/lib/AST/FormatString.cpp b/clang/lib/AST/FormatString.cpp
@@ -488,7 +488,6 @@ ArgType::matchesType(ASTContext &C, QualType argTy) const {
                 return NoMatchPromotionTypeConfusion;
               break;
             case BuiltinType::Half:
-            case BuiltinType::Float16:
             case BuiltinType::Float:
               if (T == C.DoubleTy)
                 return MatchPromotion;

diff --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -114,13 +114,17 @@ bool ByteCodeExprGen<Emitter>::VisitCastExpr(const CastExpr *CE) {
   }
 
   case CK_FloatingCast: {
+    if (DiscardResult)
+      return this->discard(SubExpr);
     if (!this->visit(SubExpr))
       return false;
     const auto *TargetSemantics = &Ctx.getFloatSemantics(CE->getType());
     return this->emitCastFP(TargetSemantics, getRoundingMode(CE), CE);
   }
 
   case CK_IntegralToFloating: {
+    if (DiscardResult)
+      return this->discard(SubExpr);
     std::optional<PrimType> FromT = classify(SubExpr->getType());
     if (!FromT)
       return false;
@@ -135,6 +139,9 @@ bool ByteCodeExprGen<Emitter>::VisitCastExpr(const CastExpr *CE) {
 
   case CK_FloatingToBoolean:
   case CK_FloatingToIntegral: {
+    if (DiscardResult)
+      return this->discard(SubExpr);
+
     std::optional<PrimType> ToT = classify(CE->getType());
 
     if (!ToT)

diff --git a/clang/lib/AST/Interp/Descriptor.cpp b/clang/lib/AST/Interp/Descriptor.cpp
@@ -275,8 +275,8 @@ Descriptor::Descriptor(const DeclTy &D, const Descriptor *Elem, MetadataSize MD,
 }
 
 /// Unknown-size arrays of composite elements.
-Descriptor::Descriptor(const DeclTy &D, Descriptor *Elem, bool IsTemporary,
-                       UnknownSize)
+Descriptor::Descriptor(const DeclTy &D, const Descriptor *Elem,
+                       bool IsTemporary, UnknownSize)
     : Source(D), ElemSize(Elem->getAllocSize() + sizeof(InlineDescriptor)),
       Size(UnknownSizeMark), MDSize(0),
       AllocSize(alignof(void *) + sizeof(InitMapPtr)), ElemDesc(Elem),
@@ -286,7 +286,7 @@ Descriptor::Descriptor(const DeclTy &D, Descriptor *Elem, bool IsTemporary,
 }
 
 /// Composite records.
-Descriptor::Descriptor(const DeclTy &D, Record *R, MetadataSize MD,
+Descriptor::Descriptor(const DeclTy &D, const Record *R, MetadataSize MD,
                        bool IsConst, bool IsTemporary, bool IsMutable)
     : Source(D), ElemSize(std::max<size_t>(alignof(void *), R->getFullSize())),
       Size(ElemSize), MDSize(MD.value_or(0)), AllocSize(Size + MDSize),

diff --git a/clang/lib/AST/Interp/Descriptor.h b/clang/lib/AST/Interp/Descriptor.h
@@ -100,7 +100,7 @@ struct Descriptor final {
   static constexpr MetadataSize InlineDescMD = sizeof(InlineDescriptor);
 
   /// Pointer to the record, if block contains records.
-  Record *const ElemRecord = nullptr;
+  const Record *const ElemRecord = nullptr;
   /// Descriptor of the array element.
   const Descriptor *const ElemDesc = nullptr;
   /// Flag indicating if the block is mutable.
@@ -135,10 +135,11 @@ struct Descriptor final {
              unsigned NumElems, bool IsConst, bool IsTemporary, bool IsMutable);
 
   /// Allocates a descriptor for an array of composites of unknown size.
-  Descriptor(const DeclTy &D, Descriptor *Elem, bool IsTemporary, UnknownSize);
+  Descriptor(const DeclTy &D, const Descriptor *Elem, bool IsTemporary,
+             UnknownSize);
 
   /// Allocates a descriptor for a record.
-  Descriptor(const DeclTy &D, Record *R, MetadataSize MD, bool IsConst,
+  Descriptor(const DeclTy &D, const Record *R, MetadataSize MD, bool IsConst,
              bool IsTemporary, bool IsMutable);
 
   Descriptor(const DeclTy &D, MetadataSize MD);

diff --git a/clang/lib/AST/Interp/Interp.cpp b/clang/lib/AST/Interp/Interp.cpp
@@ -290,10 +290,10 @@ bool CheckInitialized(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
 }
 
 bool CheckLoad(InterpState &S, CodePtr OpPC, const Pointer &Ptr) {
-  if (!CheckDummy(S, OpPC, Ptr))
-    return false;
   if (!CheckLive(S, OpPC, Ptr, AK_Read))
     return false;
+  if (!CheckDummy(S, OpPC, Ptr))
+    return false;
   if (!CheckExtern(S, OpPC, Ptr))
     return false;
   if (!CheckRange(S, OpPC, Ptr, AK_Read))

diff --git a/clang/lib/AST/Interp/Interp.h b/clang/lib/AST/Interp/Interp.h
@@ -37,7 +37,6 @@
 namespace clang {
 namespace interp {
 
-using APInt = llvm::APInt;
 using APSInt = llvm::APSInt;
 
 /// Convert a value to an APValue.
@@ -1814,9 +1813,6 @@ inline bool ArrayElemPtr(InterpState &S, CodePtr OpPC) {
   const T &Offset = S.Stk.pop<T>();
   const Pointer &Ptr = S.Stk.peek<Pointer>();
 
-  if (!CheckArray(S, OpPC, Ptr))
-    return false;
-
   if (!OffsetHelper<T, ArithOp::Add>(S, OpPC, Offset, Ptr))
     return false;
 
@@ -1844,9 +1840,6 @@ inline bool ArrayElemPtrPop(InterpState &S, CodePtr OpPC) {
   const T &Offset = S.Stk.pop<T>();
   const Pointer &Ptr = S.Stk.pop<Pointer>();
 
-  if (!CheckArray(S, OpPC, Ptr))
-    return false;
-
   if (!OffsetHelper<T, ArithOp::Add>(S, OpPC, Offset, Ptr))
     return false;
 

diff --git a/clang/lib/AST/Interp/Program.cpp b/clang/lib/AST/Interp/Program.cpp
@@ -315,14 +315,14 @@ Descriptor *Program::createDescriptor(const DeclTy &D, const Type *Ty,
                                       bool IsConst, bool IsTemporary,
                                       bool IsMutable, const Expr *Init) {
   // Classes and structures.
-  if (auto *RT = Ty->getAs<RecordType>()) {
-    if (auto *Record = getOrCreateRecord(RT->getDecl()))
+  if (const auto *RT = Ty->getAs<RecordType>()) {
+    if (const auto *Record = getOrCreateRecord(RT->getDecl()))
       return allocateDescriptor(D, Record, MDSize, IsConst, IsTemporary,
                                 IsMutable);
   }
 
   // Arrays.
-  if (auto ArrayType = Ty->getAsArrayTypeUnsafe()) {
+  if (const auto ArrayType = Ty->getAsArrayTypeUnsafe()) {
     QualType ElemTy = ArrayType->getElementType();
     // Array of well-known bounds.
     if (auto CAT = dyn_cast<ConstantArrayType>(ArrayType)) {
@@ -338,7 +338,7 @@ Descriptor *Program::createDescriptor(const DeclTy &D, const Type *Ty,
       } else {
         // Arrays of composites. In this case, the array is a list of pointers,
         // followed by the actual elements.
-        Descriptor *ElemDesc = createDescriptor(
+        const Descriptor *ElemDesc = createDescriptor(
             D, ElemTy.getTypePtr(), std::nullopt, IsConst, IsTemporary);
         if (!ElemDesc)
           return nullptr;
@@ -358,8 +358,8 @@ Descriptor *Program::createDescriptor(const DeclTy &D, const Type *Ty,
         return allocateDescriptor(D, *T, IsTemporary,
                                   Descriptor::UnknownSize{});
       } else {
-        Descriptor *Desc = createDescriptor(D, ElemTy.getTypePtr(), MDSize,
-                                            IsConst, IsTemporary);
+        const Descriptor *Desc = createDescriptor(D, ElemTy.getTypePtr(),
+                                                  MDSize, IsConst, IsTemporary);
         if (!Desc)
           return nullptr;
         return allocateDescriptor(D, Desc, IsTemporary,
@@ -369,14 +369,14 @@ Descriptor *Program::createDescriptor(const DeclTy &D, const Type *Ty,
   }
 
   // Atomic types.
-  if (auto *AT = Ty->getAs<AtomicType>()) {
+  if (const auto *AT = Ty->getAs<AtomicType>()) {
     const Type *InnerTy = AT->getValueType().getTypePtr();
     return createDescriptor(D, InnerTy, MDSize, IsConst, IsTemporary,
                             IsMutable);
   }
 
   // Complex types - represented as arrays of elements.
-  if (auto *CT = Ty->getAs<ComplexType>()) {
+  if (const auto *CT = Ty->getAs<ComplexType>()) {
     PrimType ElemTy = *Ctx.classify(CT->getElementType());
     return allocateDescriptor(D, ElemTy, MDSize, 2, IsConst, IsTemporary,
                               IsMutable);

diff --git a/clang/lib/AST/TextNodeDumper.cpp b/clang/lib/AST/TextNodeDumper.cpp
@@ -1094,6 +1094,16 @@ void clang::TextNodeDumper::VisitReturnStmt(const ReturnStmt *Node) {
   }
 }
 
+void clang::TextNodeDumper::VisitCoawaitExpr(const CoawaitExpr *Node) {
+  if (Node->isImplicit())
+    OS << " implicit";
+}
+
+void clang::TextNodeDumper::VisitCoreturnStmt(const CoreturnStmt *Node) {
+  if (Node->isImplicit())
+    OS << " implicit";
+}
+
 void TextNodeDumper::VisitConstantExpr(const ConstantExpr *Node) {
   if (Node->hasAPValueResult())
     AddChild("value",

diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
@@ -2604,19 +2604,22 @@ bool QualType::isTrivialType(const ASTContext &Context) const {
   return false;
 }
 
-bool QualType::isTriviallyCopyableType(const ASTContext &Context) const {
-  if ((*this)->isArrayType())
-    return Context.getBaseElementType(*this).isTriviallyCopyableType(Context);
+static bool isTriviallyCopyableTypeImpl(const QualType &type,
+                                        const ASTContext &Context,
+                                        bool IsCopyConstructible) {
+  if (type->isArrayType())
+    return isTriviallyCopyableTypeImpl(Context.getBaseElementType(type),
+                                       Context, IsCopyConstructible);
 
-  if (hasNonTrivialObjCLifetime())
+  if (type.hasNonTrivialObjCLifetime())
     return false;
 
   // C++11 [basic.types]p9 - See Core 2094
   //   Scalar types, trivially copyable class types, arrays of such types, and
   //   cv-qualified versions of these types are collectively
-  //   called trivially copyable types.
+  //   called trivially copy constructible types.
 
-  QualType CanonicalType = getCanonicalType();
+  QualType CanonicalType = type.getCanonicalType();
   if (CanonicalType->isDependentType())
     return false;
 
@@ -2634,16 +2637,29 @@ bool QualType::isTriviallyCopyableType(const ASTContext &Context) const {
 
   if (const auto *RT = CanonicalType->getAs<RecordType>()) {
     if (const auto *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
-      if (!ClassDecl->isTriviallyCopyable()) return false;
+      if (IsCopyConstructible) {
+        return ClassDecl->isTriviallyCopyConstructible();
+      } else {
+        return ClassDecl->isTriviallyCopyable();
+      }
     }
-
     return true;
   }
-
   // No other types can match.
   return false;
 }
 
+bool QualType::isTriviallyCopyableType(const ASTContext &Context) const {
+  return isTriviallyCopyableTypeImpl(*this, Context,
+                                     /*IsCopyConstructible=*/false);
+}
+
+bool QualType::isTriviallyCopyConstructibleType(
+    const ASTContext &Context) const {
+  return isTriviallyCopyableTypeImpl(*this, Context,
+                                     /*IsCopyConstructible=*/true);
+}
+
 bool QualType::isTriviallyRelocatableType(const ASTContext &Context) const {
   QualType BaseElementType = Context.getBaseElementType(*this);
 
@@ -3414,6 +3430,13 @@ StringRef FunctionType::getNameForCallConv(CallingConv CC) {
   llvm_unreachable("Invalid calling convention.");
 }
 
+void FunctionProtoType::ExceptionSpecInfo::instantiate() {
+  assert(Type == EST_Uninstantiated);
+  NoexceptExpr =
+      cast<FunctionProtoType>(SourceTemplate->getType())->getNoexceptExpr();
+  Type = EST_DependentNoexcept;
+}
+
 FunctionProtoType::FunctionProtoType(QualType result, ArrayRef<QualType> params,
                                      QualType canonical,
                                      const ExtProtoInfo &epi)

diff --git a/clang/lib/Analysis/ExprMutationAnalyzer.cpp b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
diff --git a/clang/lib/Analysis/PathDiagnostic.cpp b/clang/lib/Analysis/PathDiagnostic.cpp
@@ -50,12 +50,7 @@
 using namespace clang;
 using namespace ento;
 
-static StringRef StripTrailingDots(StringRef s) {
-  for (StringRef::size_type i = s.size(); i != 0; --i)
-    if (s[i - 1] != '.')
-      return s.substr(0, i);
-  return {};
-}
+static StringRef StripTrailingDots(StringRef s) { return s.rtrim('.'); }
 
 PathDiagnosticPiece::PathDiagnosticPiece(StringRef s,
                                          Kind k, DisplayHint hint)

diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp b/clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -721,6 +721,34 @@ class UnsafeBufferUsageAttrGadget : public WarningGadget {
   DeclUseList getClaimedVarUseSites() const override { return {}; }
 };
 
+// Warning gadget for unsafe invocation of span::data method.
+// Triggers when the pointer returned by the invocation is immediately
+// cast to a larger type.
+
+class DataInvocationGadget : public WarningGadget {
+  constexpr static const char *const OpTag = "data_invocation_expr";
+  const ExplicitCastExpr *Op;
+
+public:
+  DataInvocationGadget(const MatchFinder::MatchResult &Result)
+      : WarningGadget(Kind::DataInvocation),
+        Op(Result.Nodes.getNodeAs<ExplicitCastExpr>(OpTag)) {}
+
+  static bool classof(const Gadget *G) {
+    return G->getKind() == Kind::DataInvocation;
+  }
+
+  static Matcher matcher() {
+    return stmt(
+        explicitCastExpr(has(cxxMemberCallExpr(callee(cxxMethodDecl(
+                             hasName("data"), ofClass(hasName("std::span")))))))
+            .bind(OpTag));
+  }
+  const Stmt *getBaseStmt() const override { return Op; }
+
+  DeclUseList getClaimedVarUseSites() const override { return {}; }
+};
+
 // Represents expressions of the form `DRE[*]` in the Unspecified Lvalue
 // Context (see `isInUnspecifiedLvalueContext`).
 // Note here `[]` is the built-in subscript operator.
@@ -2657,8 +2685,8 @@ void clang::checkUnsafeBufferUsage(const Decl *D,
     // every problematic operation and consider it done. No need to deal
     // with fixable gadgets, no need to group operations by variable.
     for (const auto &G : WarningGadgets) {
-      Handler.handleUnsafeOperation(G->getBaseStmt(),
-                                    /*IsRelatedToDecl=*/false);
+      Handler.handleUnsafeOperation(G->getBaseStmt(), /*IsRelatedToDecl=*/false,
+                                    D->getASTContext());
     }
 
     // This return guarantees that most of the machine doesn't run when
@@ -2893,7 +2921,8 @@ void clang::checkUnsafeBufferUsage(const Decl *D,
                   Tracker, Handler, VarGrpMgr);
 
   for (const auto &G : UnsafeOps.noVar) {
-    Handler.handleUnsafeOperation(G->getBaseStmt(), /*IsRelatedToDecl=*/false);
+    Handler.handleUnsafeOperation(G->getBaseStmt(), /*IsRelatedToDecl=*/false,
+                                  D->getASTContext());
   }
 
   for (const auto &[VD, WarningGadgets] : UnsafeOps.byVar) {
@@ -2904,7 +2933,8 @@ void clang::checkUnsafeBufferUsage(const Decl *D,
                                       : FixItList{},
                                       D);
     for (const auto &G : WarningGadgets) {
-      Handler.handleUnsafeOperation(G->getBaseStmt(), /*IsRelatedToDecl=*/true);
+      Handler.handleUnsafeOperation(G->getBaseStmt(), /*IsRelatedToDecl=*/true,
+                                    D->getASTContext());
     }
   }
 }
diff --git a/clang/lib/Basic/Targets/ARM.cpp b/clang/lib/Basic/Targets/ARM.cpp
@@ -17,6 +17,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/TargetParser/ARMTargetParser.h"
 
 using namespace clang;
 using namespace clang::targets;
@@ -837,6 +838,69 @@ void ARMTargetInfo::getTargetDefines(const LangOptions &Opts,
   if (Opts.RWPI)
     Builder.defineMacro("__ARM_RWPI", "1");
 
+  // Macros for enabling co-proc intrinsics
+  uint64_t FeatureCoprocBF = 0;
+  switch (ArchKind) {
+  default:
+    break;
+  case llvm::ARM::ArchKind::ARMV4:
+  case llvm::ARM::ArchKind::ARMV4T:
+    // Filter __arm_ldcl and __arm_stcl in acle.h
+    FeatureCoprocBF = isThumb() ? 0 : FEATURE_COPROC_B1;
+    break;
+  case llvm::ARM::ArchKind::ARMV5T:
+    FeatureCoprocBF = isThumb() ? 0 : FEATURE_COPROC_B1 | FEATURE_COPROC_B2;
+    break;
+  case llvm::ARM::ArchKind::ARMV5TE:
+  case llvm::ARM::ArchKind::ARMV5TEJ:
+    if (!isThumb())
+      FeatureCoprocBF =
+          FEATURE_COPROC_B1 | FEATURE_COPROC_B2 | FEATURE_COPROC_B3;
+    break;
+  case llvm::ARM::ArchKind::ARMV6:
+  case llvm::ARM::ArchKind::ARMV6K:
+  case llvm::ARM::ArchKind::ARMV6KZ:
+  case llvm::ARM::ArchKind::ARMV6T2:
+    if (!isThumb() || ArchKind == llvm::ARM::ArchKind::ARMV6T2)
+      FeatureCoprocBF = FEATURE_COPROC_B1 | FEATURE_COPROC_B2 |
+                        FEATURE_COPROC_B3 | FEATURE_COPROC_B4;
+    break;
+  case llvm::ARM::ArchKind::ARMV7A:
+  case llvm::ARM::ArchKind::ARMV7R:
+  case llvm::ARM::ArchKind::ARMV7M:
+  case llvm::ARM::ArchKind::ARMV7S:
+  case llvm::ARM::ArchKind::ARMV7EM:
+    FeatureCoprocBF = FEATURE_COPROC_B1 | FEATURE_COPROC_B2 |
+                      FEATURE_COPROC_B3 | FEATURE_COPROC_B4;
+    break;
+  case llvm::ARM::ArchKind::ARMV8A:
+  case llvm::ARM::ArchKind::ARMV8R:
+  case llvm::ARM::ArchKind::ARMV8_1A:
+  case llvm::ARM::ArchKind::ARMV8_2A:
+  case llvm::ARM::ArchKind::ARMV8_3A:
+  case llvm::ARM::ArchKind::ARMV8_4A:
+  case llvm::ARM::ArchKind::ARMV8_5A:
+  case llvm::ARM::ArchKind::ARMV8_6A:
+  case llvm::ARM::ArchKind::ARMV8_7A:
+  case llvm::ARM::ArchKind::ARMV8_8A:
+  case llvm::ARM::ArchKind::ARMV8_9A:
+  case llvm::ARM::ArchKind::ARMV9A:
+  case llvm::ARM::ArchKind::ARMV9_1A:
+  case llvm::ARM::ArchKind::ARMV9_2A:
+  case llvm::ARM::ArchKind::ARMV9_3A:
+  case llvm::ARM::ArchKind::ARMV9_4A:
+    // Filter __arm_cdp, __arm_ldcl, __arm_stcl in arm_acle.h
+    FeatureCoprocBF = FEATURE_COPROC_B1 | FEATURE_COPROC_B3;
+    break;
+  case llvm::ARM::ArchKind::ARMV8MMainline:
+  case llvm::ARM::ArchKind::ARMV8_1MMainline:
+    FeatureCoprocBF = FEATURE_COPROC_B1 | FEATURE_COPROC_B2 |
+                      FEATURE_COPROC_B3 | FEATURE_COPROC_B4;
+    break;
+  }
+  Builder.defineMacro("__ARM_FEATURE_COPROC",
+                      "0x" + Twine::utohexstr(FeatureCoprocBF));
+
   if (ArchKind == llvm::ARM::ArchKind::XSCALE)
     Builder.defineMacro("__XSCALE__");
 

diff --git a/clang/lib/Basic/Targets/ARM.h b/clang/lib/Basic/Targets/ARM.h
@@ -100,6 +100,19 @@ class LLVM_LIBRARY_VISIBILITY ARMTargetInfo : public TargetInfo {
   };
   uint32_t HW_FP;
 
+  enum {
+    /// __arm_cdp __arm_ldc, __arm_ldcl, __arm_stc,
+    /// __arm_stcl, __arm_mcr and __arm_mrc
+    FEATURE_COPROC_B1 = (1 << 0),
+    /// __arm_cdp2, __arm_ldc2, __arm_stc2, __arm_ldc2l,
+    /// __arm_stc2l, __arm_mcr2 and __arm_mrc2
+    FEATURE_COPROC_B2 = (1 << 1),
+    /// __arm_mcrr, __arm_mrrc
+    FEATURE_COPROC_B3 = (1 << 2),
+    /// __arm_mcrr2,  __arm_mrrc2
+    FEATURE_COPROC_B4 = (1 << 3),
+  };
+
   void setABIAAPCS();
   void setABIAPCS(bool IsAAPCS16);
 

diff --git a/clang/lib/Basic/Targets/AVR.h b/clang/lib/Basic/Targets/AVR.h
@@ -146,7 +146,9 @@ class LLVM_LIBRARY_VISIBILITY AVRTargetInfo : public TargetInfo {
     case 'R': // Integer constant (Range: -6 to 5)
       Info.setRequiresImmediate(-6, 5);
       return true;
-    case 'G': // Floating point constant
+    case 'G': // Floating point constant 0.0
+      Info.setRequiresImmediate(0);
+      return true;
     case 'Q': // A memory address based on Y or Z pointer with displacement.
       return true;
     }

diff --git a/clang/lib/Basic/Targets/RISCV.cpp b/clang/lib/Basic/Targets/RISCV.cpp
@@ -237,22 +237,15 @@ ArrayRef<Builtin::Info> RISCVTargetInfo::getTargetBuiltins() const {
 
 static std::vector<std::string>
 collectNonISAExtFeature(ArrayRef<std::string> FeaturesNeedOverride, int XLen) {
-  auto ParseResult =
-      llvm::RISCVISAInfo::parseFeatures(XLen, FeaturesNeedOverride);
-
-  if (!ParseResult) {
-    consumeError(ParseResult.takeError());
-    return std::vector<std::string>();
-  }
-
-  std::vector<std::string> ImpliedFeatures = (*ParseResult)->toFeatureVector();
-
   std::vector<std::string> NonISAExtFeatureVec;
 
+  auto IsNonISAExtFeature = [](const std::string &Feature) {
+    assert(Feature.size() > 1 && (Feature[0] == '+' || Feature[0] == '-'));
+    StringRef Ext = StringRef(Feature).drop_front(); // drop the +/-
+    return !llvm::RISCVISAInfo::isSupportedExtensionFeature(Ext);
+  };
   llvm::copy_if(FeaturesNeedOverride, std::back_inserter(NonISAExtFeatureVec),
-                [&](const std::string &Feat) {
-                  return !llvm::is_contained(ImpliedFeatures, Feat);
-                });
+                IsNonISAExtFeature);
 
   return NonISAExtFeatureVec;
 }
@@ -303,7 +296,7 @@ bool RISCVTargetInfo::initFeatureMap(
   }
 
   // RISCVISAInfo makes implications for ISA features
-  std::vector<std::string> ImpliedFeatures = (*ParseResult)->toFeatureVector();
+  std::vector<std::string> ImpliedFeatures = (*ParseResult)->toFeatures();
 
   // parseFeatures normalizes the feature set by dropping any explicit
   // negatives, and non-extension features.  We need to preserve the later
@@ -420,7 +413,7 @@ static void handleFullArchString(StringRef FullArchStr,
     // Forward the invalid FullArchStr.
     Features.push_back("+" + FullArchStr.str());
   } else {
-    std::vector<std::string> FeatStrings = (*RII)->toFeatureVector();
+    std::vector<std::string> FeatStrings = (*RII)->toFeatures();
     Features.insert(Features.end(), FeatStrings.begin(), FeatStrings.end());
   }
 }

diff --git a/clang/lib/Basic/Targets/X86.cpp b/clang/lib/Basic/Targets/X86.cpp
@@ -295,11 +295,13 @@ bool X86TargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
       HasAVX512BF16 = true;
     } else if (Feature == "+avx512er") {
       HasAVX512ER = true;
+      Diags.Report(diag::warn_knl_knm_isa_support_removed);
     } else if (Feature == "+avx512fp16") {
       HasAVX512FP16 = true;
       HasLegalHalfType = true;
     } else if (Feature == "+avx512pf") {
       HasAVX512PF = true;
+      Diags.Report(diag::warn_knl_knm_isa_support_removed);
     } else if (Feature == "+avx512dq") {
       HasAVX512DQ = true;
     } else if (Feature == "+avx512bitalg") {
@@ -358,6 +360,7 @@ bool X86TargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
       HasPREFETCHI = true;
     } else if (Feature == "+prefetchwt1") {
       HasPREFETCHWT1 = true;
+      Diags.Report(diag::warn_knl_knm_isa_support_removed);
     } else if (Feature == "+clzero") {
       HasCLZERO = true;
     } else if (Feature == "+cldemote") {

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -9681,8 +9681,8 @@ Value *CodeGenFunction::EmitSVEMaskedStore(const CallExpr *E,
   bool IsQuadStore = false;
 
   switch (IntrinsicID) {
-  case Intrinsic::aarch64_sve_st1uwq:
-  case Intrinsic::aarch64_sve_st1udq:
+  case Intrinsic::aarch64_sve_st1wq:
+  case Intrinsic::aarch64_sve_st1dq:
     AddrMemoryTy = llvm::ScalableVectorType::get(MemEltTy, 1);
     PredTy =
         llvm::ScalableVectorType::get(IntegerType::get(getLLVMContext(), 1), 1);
@@ -10430,6 +10430,26 @@ Value *CodeGenFunction::EmitAArch64BuiltinExpr(unsigned BuiltinID,
     return Builder.CreateCall(F, llvm::ConstantInt::get(Int32Ty, HintID));
   }
 
+  if (BuiltinID == clang::AArch64::BI__builtin_arm_get_sme_state) {
+    // Create call to __arm_sme_state and store the results to the two pointers.
+    CallInst *CI = EmitRuntimeCall(CGM.CreateRuntimeFunction(
+        llvm::FunctionType::get(StructType::get(CGM.Int64Ty, CGM.Int64Ty), {},
+                                false),
+        "__arm_sme_state"));
+    auto Attrs =
+        AttributeList()
+            .addFnAttribute(getLLVMContext(), "aarch64_pstate_sm_compatible")
+            .addFnAttribute(getLLVMContext(), "aarch64_pstate_za_preserved");
+    CI->setAttributes(Attrs);
+    CI->setCallingConv(
+        llvm::CallingConv::
+            AArch64_SME_ABI_Support_Routines_PreserveMost_From_X2);
+    Builder.CreateStore(Builder.CreateExtractValue(CI, 0),
+                        EmitPointerWithAlignment(E->getArg(0)));
+    return Builder.CreateStore(Builder.CreateExtractValue(CI, 1),
+                               EmitPointerWithAlignment(E->getArg(1)));
+  }
+
   if (BuiltinID == clang::AArch64::BI__builtin_arm_rbit) {
     assert((getContext().getTypeSize(E->getType()) == 32) &&
            "rbit of unusual size!");

diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
@@ -856,6 +856,7 @@ void CodeGenFunction::EmitConstructorBody(FunctionArgList &Args) {
     EnterCXXTryStmt(*cast<CXXTryStmt>(Body), true);
 
   incrementProfileCounter(Body);
+  maybeCreateMCDCCondBitmap();
 
   RunCleanupsScope RunCleanups(*this);
 
@@ -1444,8 +1445,10 @@ void CodeGenFunction::EmitDestructorBody(FunctionArgList &Args) {
   }
 
   Stmt *Body = Dtor->getBody();
-  if (Body)
+  if (Body) {
     incrementProfileCounter(Body);
+    maybeCreateMCDCCondBitmap();
+  }
 
   // The call to operator delete in a deleting destructor happens
   // outside of the function-try-block, which means it's always
@@ -1548,6 +1551,7 @@ void CodeGenFunction::emitImplicitAssignmentOperatorBody(FunctionArgList &Args)
   LexicalScope Scope(*this, RootCS->getSourceRange());
 
   incrementProfileCounter(RootCS);
+  maybeCreateMCDCCondBitmap();
   AssignmentMemcpyizer AM(*this, AssignOp, Args);
   for (auto *I : RootCS->body())
     AM.emitAssignment(I);

diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
@@ -156,7 +156,9 @@ static const EHPersonality &getObjCPersonality(const TargetInfo &Target,
   case ObjCRuntime::WatchOS:
     return EHPersonality::NeXT_ObjC;
   case ObjCRuntime::GNUstep:
-    if (L.ObjCRuntime.getVersion() >= VersionTuple(1, 7))
+    if (T.isOSCygMing())
+      return EHPersonality::GNU_CPlusPlus_SEH;
+    else if (L.ObjCRuntime.getVersion() >= VersionTuple(1, 7))
       return EHPersonality::GNUstep_ObjC;
     [[fallthrough]];
   case ObjCRuntime::GCC:
@@ -210,7 +212,8 @@ static const EHPersonality &getObjCXXPersonality(const TargetInfo &Target,
     return getObjCPersonality(Target, L);
 
   case ObjCRuntime::GNUstep:
-    return EHPersonality::GNU_ObjCXX;
+    return Target.getTriple().isOSCygMing() ? EHPersonality::GNU_CPlusPlus_SEH
+                                            : EHPersonality::GNU_ObjCXX;
 
   // The GCC runtime's personality function inherently doesn't support
   // mixed EH.  Use the ObjC personality just to avoid returning null.

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -4564,6 +4564,12 @@ Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
     if (LHSCondVal) { // If we have 1 && X, just emit X.
       CGF.incrementProfileCounter(E);
 
+      // If the top of the logical operator nest, reset the MCDC temp to 0.
+      if (CGF.MCDCLogOpStack.empty())
+        CGF.maybeResetMCDCCondBitmap(E);
+
+      CGF.MCDCLogOpStack.push_back(E);
+
       Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
 
       // If we're generating for profiling or coverage, generate a branch to a
@@ -4572,6 +4578,7 @@ Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
       // "FalseBlock" after the increment is done.
       if (InstrumentRegions &&
           CodeGenFunction::isInstrumentedCondition(E->getRHS())) {
+        CGF.maybeUpdateMCDCCondBitmap(E->getRHS(), RHSCond);
         llvm::BasicBlock *FBlock = CGF.createBasicBlock("land.end");
         llvm::BasicBlock *RHSBlockCnt = CGF.createBasicBlock("land.rhscnt");
         Builder.CreateCondBr(RHSCond, RHSBlockCnt, FBlock);
@@ -4581,6 +4588,11 @@ Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
         CGF.EmitBlock(FBlock);
       }
 
+      CGF.MCDCLogOpStack.pop_back();
+      // If the top of the logical operator nest, update the MCDC bitmap.
+      if (CGF.MCDCLogOpStack.empty())
+        CGF.maybeUpdateMCDCTestVectorBitmap(E);
+
       // ZExt result to int or bool.
       return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext");
     }
@@ -4590,6 +4602,12 @@ Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
       return llvm::Constant::getNullValue(ResTy);
   }
 
+  // If the top of the logical operator nest, reset the MCDC temp to 0.
+  if (CGF.MCDCLogOpStack.empty())
+    CGF.maybeResetMCDCCondBitmap(E);
+
+  CGF.MCDCLogOpStack.push_back(E);
+
   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end");
   llvm::BasicBlock *RHSBlock  = CGF.createBasicBlock("land.rhs");
 
@@ -4622,6 +4640,7 @@ Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
   // condition coverage.
   if (InstrumentRegions &&
       CodeGenFunction::isInstrumentedCondition(E->getRHS())) {
+    CGF.maybeUpdateMCDCCondBitmap(E->getRHS(), RHSCond);
     llvm::BasicBlock *RHSBlockCnt = CGF.createBasicBlock("land.rhscnt");
     Builder.CreateCondBr(RHSCond, RHSBlockCnt, ContBlock);
     CGF.EmitBlock(RHSBlockCnt);
@@ -4639,6 +4658,11 @@ Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
   // Insert an entry into the phi node for the edge with the value of RHSCond.
   PN->addIncoming(RHSCond, RHSBlock);
 
+  CGF.MCDCLogOpStack.pop_back();
+  // If the top of the logical operator nest, update the MCDC bitmap.
+  if (CGF.MCDCLogOpStack.empty())
+    CGF.maybeUpdateMCDCTestVectorBitmap(E);
+
   // Artificial location to preserve the scope information
   {
     auto NL = ApplyDebugLocation::CreateArtificial(CGF);
@@ -4680,6 +4704,12 @@ Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
     if (!LHSCondVal) { // If we have 0 || X, just emit X.
       CGF.incrementProfileCounter(E);
 
+      // If the top of the logical operator nest, reset the MCDC temp to 0.
+      if (CGF.MCDCLogOpStack.empty())
+        CGF.maybeResetMCDCCondBitmap(E);
+
+      CGF.MCDCLogOpStack.push_back(E);
+
       Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
 
       // If we're generating for profiling or coverage, generate a branch to a
@@ -4688,6 +4718,7 @@ Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
       // "FalseBlock" after the increment is done.
       if (InstrumentRegions &&
           CodeGenFunction::isInstrumentedCondition(E->getRHS())) {
+        CGF.maybeUpdateMCDCCondBitmap(E->getRHS(), RHSCond);
         llvm::BasicBlock *FBlock = CGF.createBasicBlock("lor.end");
         llvm::BasicBlock *RHSBlockCnt = CGF.createBasicBlock("lor.rhscnt");
         Builder.CreateCondBr(RHSCond, FBlock, RHSBlockCnt);
@@ -4697,6 +4728,11 @@ Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
         CGF.EmitBlock(FBlock);
       }
 
+      CGF.MCDCLogOpStack.pop_back();
+      // If the top of the logical operator nest, update the MCDC bitmap.
+      if (CGF.MCDCLogOpStack.empty())
+        CGF.maybeUpdateMCDCTestVectorBitmap(E);
+
       // ZExt result to int or bool.
       return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext");
     }
@@ -4706,6 +4742,12 @@ Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
       return llvm::ConstantInt::get(ResTy, 1);
   }
 
+  // If the top of the logical operator nest, reset the MCDC temp to 0.
+  if (CGF.MCDCLogOpStack.empty())
+    CGF.maybeResetMCDCCondBitmap(E);
+
+  CGF.MCDCLogOpStack.push_back(E);
+
   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end");
   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs");
 
@@ -4742,6 +4784,7 @@ Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
   // condition coverage.
   if (InstrumentRegions &&
       CodeGenFunction::isInstrumentedCondition(E->getRHS())) {
+    CGF.maybeUpdateMCDCCondBitmap(E->getRHS(), RHSCond);
     llvm::BasicBlock *RHSBlockCnt = CGF.createBasicBlock("lor.rhscnt");
     Builder.CreateCondBr(RHSCond, ContBlock, RHSBlockCnt);
     CGF.EmitBlock(RHSBlockCnt);
@@ -4755,6 +4798,11 @@ Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
   CGF.EmitBlock(ContBlock);
   PN->addIncoming(RHSCond, RHSBlock);
 
+  CGF.MCDCLogOpStack.pop_back();
+  // If the top of the logical operator nest, update the MCDC bitmap.
+  if (CGF.MCDCLogOpStack.empty())
+    CGF.maybeUpdateMCDCTestVectorBitmap(E);
+
   // ZExt result to int.
   return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext");
 }
@@ -4899,6 +4947,10 @@ VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
     return Builder.CreateSelect(CondV, LHS, RHS, "cond");
   }
 
+  // If the top of the logical operator nest, reset the MCDC temp to 0.
+  if (CGF.MCDCLogOpStack.empty())
+    CGF.maybeResetMCDCCondBitmap(condExpr);
+
   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
@@ -4934,6 +4986,11 @@ VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
   llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond");
   PN->addIncoming(LHS, LHSBlock);
   PN->addIncoming(RHS, RHSBlock);
+
+  // If the top of the logical operator nest, update the MCDC bitmap.
+  if (CGF.MCDCLogOpStack.empty())
+    CGF.maybeUpdateMCDCTestVectorBitmap(condExpr);
+
   return PN;
 }
 
@@ -5292,8 +5349,8 @@ static GEPOffsetAndOverflow EmitGEPOffsetInBytes(Value *BasePtr, Value *GEPVal,
     } else {
       // Otherwise this is array-like indexing. The local offset is the index
       // multiplied by the element size.
-      auto *ElementSize = llvm::ConstantInt::get(
-          IntPtrTy, DL.getTypeAllocSize(GTI.getIndexedType()));
+      auto *ElementSize =
+          llvm::ConstantInt::get(IntPtrTy, GTI.getSequentialElementStride(DL));
       auto *IndexS = Builder.CreateIntCast(Index, IntPtrTy, /*isSigned=*/true);
       LocalOffset = eval(BO_Mul, ElementSize, IndexS);
     }

diff --git a/clang/lib/CodeGen/CGObjCGNU.cpp b/clang/lib/CodeGen/CGObjCGNU.cpp
@@ -168,6 +168,8 @@ class CGObjCGNU : public CGObjCRuntime {
   /// Does the current target use SEH-based exceptions? False implies
   /// Itanium-style DWARF unwinding.
   bool usesSEHExceptions;
+  /// Does the current target uses C++-based exceptions?
+  bool usesCxxExceptions;
 
   /// Helper to check if we are targeting a specific runtime version or later.
   bool isRuntime(ObjCRuntime::Kind kind, unsigned major, unsigned minor=0) {
@@ -819,12 +821,18 @@ class CGObjCGNUstep : public CGObjCGNU {
       SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy,
                              PtrToObjCSuperTy, SelectorTy);
       // If we're in ObjC++ mode, then we want to make
-      if (usesSEHExceptions) {
-          llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
-          // void objc_exception_rethrow(void)
-          ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy);
+      llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
+      if (usesCxxExceptions) {
+        // void *__cxa_begin_catch(void *e)
+        EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy);
+        // void __cxa_end_catch(void)
+        ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy);
+        // void objc_exception_rethrow(void*)
+        ExceptionReThrowFn.init(&CGM, "__cxa_rethrow", PtrTy);
+      } else if (usesSEHExceptions) {
+        // void objc_exception_rethrow(void)
+        ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy);
       } else if (CGM.getLangOpts().CPlusPlus) {
-        llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
         // void *__cxa_begin_catch(void *e)
         EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy);
         // void __cxa_end_catch(void)
@@ -833,15 +841,13 @@ class CGObjCGNUstep : public CGObjCGNU {
         ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy,
                                 PtrTy);
       } else if (R.getVersion() >= VersionTuple(1, 7)) {
-        llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
         // id objc_begin_catch(void *e)
         EnterCatchFn.init(&CGM, "objc_begin_catch", IdTy, PtrTy);
         // void objc_end_catch(void)
         ExitCatchFn.init(&CGM, "objc_end_catch", VoidTy);
         // void _Unwind_Resume_or_Rethrow(void*)
         ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy, PtrTy);
       }
-      llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
       SetPropertyAtomic.init(&CGM, "objc_setProperty_atomic", VoidTy, IdTy,
                              SelectorTy, IdTy, PtrDiffTy);
       SetPropertyAtomicCopy.init(&CGM, "objc_setProperty_atomic_copy", VoidTy,
@@ -1851,6 +1857,8 @@ class CGObjCGNUstep2 : public CGObjCGNUstep {
                     llvm::GlobalValue::HiddenVisibility :
                     llvm::GlobalValue::DefaultVisibility;
         OffsetVar->setVisibility(ivarVisibility);
+        if (ivarVisibility != llvm::GlobalValue::HiddenVisibility)
+          CGM.setGVProperties(OffsetVar, OID->getClassInterface());
         ivarBuilder.add(OffsetVar);
         // Ivar size
         ivarBuilder.addInt(Int32Ty,
@@ -2124,6 +2132,9 @@ CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
   msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
   usesSEHExceptions =
       cgm.getContext().getTargetInfo().getTriple().isWindowsMSVCEnvironment();
+  usesCxxExceptions =
+      cgm.getContext().getTargetInfo().getTriple().isOSCygMing() &&
+      isRuntime(ObjCRuntime::GNUstep, 2);
 
   CodeGenTypes &Types = CGM.getTypes();
   IntTy = cast<llvm::IntegerType>(
@@ -2210,7 +2221,10 @@ CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
 
   // void objc_exception_throw(id);
   ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
-  ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
+  ExceptionReThrowFn.init(&CGM,
+                          usesCxxExceptions ? "objc_exception_rethrow"
+                                            : "objc_exception_throw",
+                          VoidTy, IdTy);
   // int objc_sync_enter(id);
   SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy);
   // int objc_sync_exit(id);
@@ -2387,7 +2401,7 @@ llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) {
   if (usesSEHExceptions)
     return CGM.getCXXABI().getAddrOfRTTIDescriptor(T);
 
-  if (!CGM.getLangOpts().CPlusPlus)
+  if (!CGM.getLangOpts().CPlusPlus && !usesCxxExceptions)
     return CGObjCGNU::GetEHType(T);
 
   // For Objective-C++, we want to provide the ability to catch both C++ and
@@ -3993,7 +4007,7 @@ void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
     ExceptionAsObject = CGF.ObjCEHValueStack.back();
     isRethrow = true;
   }
-  if (isRethrow && usesSEHExceptions) {
+  if (isRethrow && (usesSEHExceptions || usesCxxExceptions)) {
     // For SEH, ExceptionAsObject may be undef, because the catch handler is
     // not passed it for catchalls and so it is not visible to the catch
     // funclet.  The real thrown object will still be live on the stack at this
@@ -4003,8 +4017,7 @@ void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
     // argument.
     llvm::CallBase *Throw = CGF.EmitRuntimeCallOrInvoke(ExceptionReThrowFn);
     Throw->setDoesNotReturn();
-  }
-  else {
+  } else {
     ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy);
     llvm::CallBase *Throw =
         CGF.EmitRuntimeCallOrInvoke(ExceptionThrowFn, ExceptionAsObject);

diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
@@ -837,7 +837,19 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
   if (!ThenCount && !getCurrentProfileCount() &&
       CGM.getCodeGenOpts().OptimizationLevel)
     LH = Stmt::getLikelihood(S.getThen(), S.getElse());
-  EmitBranchOnBoolExpr(S.getCond(), ThenBlock, ElseBlock, ThenCount, LH);
+
+  // When measuring MC/DC, always fully evaluate the condition up front using
+  // EvaluateExprAsBool() so that the test vector bitmap can be updated prior to
+  // executing the body of the if.then or if.else. This is useful for when
+  // there is a 'return' within the body, but this is particularly beneficial
+  // when one if-stmt is nested within another if-stmt so that all of the MC/DC
+  // updates are kept linear and consistent.
+  if (!CGM.getCodeGenOpts().MCDCCoverage)
+    EmitBranchOnBoolExpr(S.getCond(), ThenBlock, ElseBlock, ThenCount, LH);
+  else {
+    llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
+    Builder.CreateCondBr(BoolCondVal, ThenBlock, ElseBlock);
+  }
 
   // Emit the 'then' code.
   EmitBlock(ThenBlock);

diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -6406,13 +6406,11 @@ static void emitOMPAtomicCaptureExpr(CodeGenFunction &CGF,
   }
 }
 
-static void emitOMPAtomicCompareExpr(CodeGenFunction &CGF,
-                                     llvm::AtomicOrdering AO, const Expr *X,
-                                     const Expr *V, const Expr *R,
-                                     const Expr *E, const Expr *D,
-                                     const Expr *CE, bool IsXBinopExpr,
-                                     bool IsPostfixUpdate, bool IsFailOnly,
-                                     SourceLocation Loc) {
+static void emitOMPAtomicCompareExpr(
+    CodeGenFunction &CGF, llvm::AtomicOrdering AO, llvm::AtomicOrdering FailAO,
+    const Expr *X, const Expr *V, const Expr *R, const Expr *E, const Expr *D,
+    const Expr *CE, bool IsXBinopExpr, bool IsPostfixUpdate, bool IsFailOnly,
+    SourceLocation Loc) {
   llvm::OpenMPIRBuilder &OMPBuilder =
       CGF.CGM.getOpenMPRuntime().getOMPBuilder();
 
@@ -6477,13 +6475,21 @@ static void emitOMPAtomicCompareExpr(CodeGenFunction &CGF,
               R->getType().isVolatileQualified()};
   }
 
-  CGF.Builder.restoreIP(OMPBuilder.createAtomicCompare(
-      CGF.Builder, XOpVal, VOpVal, ROpVal, EVal, DVal, AO, Op, IsXBinopExpr,
-      IsPostfixUpdate, IsFailOnly));
+  if (FailAO == llvm::AtomicOrdering::NotAtomic) {
+    // fail clause was not mentionend on the
+    // "#pragma omp atomic compare" construct.
+    CGF.Builder.restoreIP(OMPBuilder.createAtomicCompare(
+        CGF.Builder, XOpVal, VOpVal, ROpVal, EVal, DVal, AO, Op, IsXBinopExpr,
+        IsPostfixUpdate, IsFailOnly));
+  } else
+    CGF.Builder.restoreIP(OMPBuilder.createAtomicCompare(
+        CGF.Builder, XOpVal, VOpVal, ROpVal, EVal, DVal, AO, Op, IsXBinopExpr,
+        IsPostfixUpdate, IsFailOnly, FailAO));
 }
 
 static void emitOMPAtomicExpr(CodeGenFunction &CGF, OpenMPClauseKind Kind,
-                              llvm::AtomicOrdering AO, bool IsPostfixUpdate,
+                              llvm::AtomicOrdering AO,
+                              llvm::AtomicOrdering FailAO, bool IsPostfixUpdate,
                               const Expr *X, const Expr *V, const Expr *R,
                               const Expr *E, const Expr *UE, const Expr *D,
                               const Expr *CE, bool IsXLHSInRHSPart,
@@ -6504,12 +6510,8 @@ static void emitOMPAtomicExpr(CodeGenFunction &CGF, OpenMPClauseKind Kind,
                              IsXLHSInRHSPart, Loc);
     break;
   case OMPC_compare: {
-    emitOMPAtomicCompareExpr(CGF, AO, X, V, R, E, D, CE, IsXLHSInRHSPart,
-                             IsPostfixUpdate, IsFailOnly, Loc);
-    break;
-  }
-  case OMPC_fail: {
-    //TODO
+    emitOMPAtomicCompareExpr(CGF, AO, FailAO, X, V, R, E, D, CE,
+                             IsXLHSInRHSPart, IsPostfixUpdate, IsFailOnly, Loc);
     break;
   }
   default:
@@ -6519,6 +6521,8 @@ static void emitOMPAtomicExpr(CodeGenFunction &CGF, OpenMPClauseKind Kind,
 
 void CodeGenFunction::EmitOMPAtomicDirective(const OMPAtomicDirective &S) {
   llvm::AtomicOrdering AO = llvm::AtomicOrdering::Monotonic;
+  // Fail Memory Clause Ordering.
+  llvm::AtomicOrdering FailAO = llvm::AtomicOrdering::NotAtomic;
   bool MemOrderingSpecified = false;
   if (S.getSingleClause<OMPSeqCstClause>()) {
     AO = llvm::AtomicOrdering::SequentiallyConsistent;
@@ -6572,12 +6576,27 @@ void CodeGenFunction::EmitOMPAtomicDirective(const OMPAtomicDirective &S) {
     }
   }
 
+  if (KindsEncountered.contains(OMPC_compare) &&
+      KindsEncountered.contains(OMPC_fail)) {
+    Kind = OMPC_compare;
+    const auto *FailClause = S.getSingleClause<OMPFailClause>();
+    if (FailClause) {
+      OpenMPClauseKind FailParameter = FailClause->getFailParameter();
+      if (FailParameter == llvm::omp::OMPC_relaxed)
+        FailAO = llvm::AtomicOrdering::Monotonic;
+      else if (FailParameter == llvm::omp::OMPC_acquire)
+        FailAO = llvm::AtomicOrdering::Acquire;
+      else if (FailParameter == llvm::omp::OMPC_seq_cst)
+        FailAO = llvm::AtomicOrdering::SequentiallyConsistent;
+    }
+  }
+
   LexicalScope Scope(*this, S.getSourceRange());
   EmitStopPoint(S.getAssociatedStmt());
-  emitOMPAtomicExpr(*this, Kind, AO, S.isPostfixUpdate(), S.getX(), S.getV(),
-                    S.getR(), S.getExpr(), S.getUpdateExpr(), S.getD(),
-                    S.getCondExpr(), S.isXLHSInRHSPart(), S.isFailOnly(),
-                    S.getBeginLoc());
+  emitOMPAtomicExpr(*this, Kind, AO, FailAO, S.isPostfixUpdate(), S.getX(),
+                    S.getV(), S.getR(), S.getExpr(), S.getUpdateExpr(),
+                    S.getD(), S.getCondExpr(), S.isXLHSInRHSPart(),
+                    S.isFailOnly(), S.getBeginLoc());
 }
 
 static void emitCommonOMPTargetDirective(CodeGenFunction &CGF,

diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -1256,6 +1256,7 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
 
 void CodeGenFunction::EmitFunctionBody(const Stmt *Body) {
   incrementProfileCounter(Body);
+  maybeCreateMCDCCondBitmap();
   if (const CompoundStmt *S = dyn_cast<CompoundStmt>(Body))
     EmitCompoundStmtWithoutScope(*S);
   else
@@ -1601,6 +1602,13 @@ bool CodeGenFunction::mightAddDeclToScope(const Stmt *S) {
 bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond,
                                                    bool &ResultBool,
                                                    bool AllowLabels) {
+  // If MC/DC is enabled, disable folding so that we can instrument all
+  // conditions to yield complete test vectors. We still keep track of
+  // folded conditions during region mapping and visualization.
+  if (!AllowLabels && CGM.getCodeGenOpts().hasProfileClangInstr() &&
+      CGM.getCodeGenOpts().MCDCCoverage)
+    return false;
+
   llvm::APSInt ResultInt;
   if (!ConstantFoldsToSimpleInteger(Cond, ResultInt, AllowLabels))
     return false;
@@ -1629,16 +1637,20 @@ bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond,
   return true;
 }
 
+/// Strip parentheses and simplistic logical-NOT operators.
+const Expr *CodeGenFunction::stripCond(const Expr *C) {
+  while (const UnaryOperator *Op = dyn_cast<UnaryOperator>(C->IgnoreParens())) {
+    if (Op->getOpcode() != UO_LNot)
+      break;
+    C = Op->getSubExpr();
+  }
+  return C->IgnoreParens();
+}
+
 /// Determine whether the given condition is an instrumentable condition
 /// (i.e. no "&&" or "||").
 bool CodeGenFunction::isInstrumentedCondition(const Expr *C) {
-  // Bypass simplistic logical-NOT operator before determining whether the
-  // condition contains any other logical operator.
-  if (const UnaryOperator *UnOp = dyn_cast<UnaryOperator>(C->IgnoreParens()))
-    if (UnOp->getOpcode() == UO_LNot)
-      C = UnOp->getSubExpr();
-
-  const BinaryOperator *BOp = dyn_cast<BinaryOperator>(C->IgnoreParens());
+  const BinaryOperator *BOp = dyn_cast<BinaryOperator>(stripCond(C));
   return (!BOp || !BOp->isLogicalOp());
 }
 
@@ -1717,35 +1729,41 @@ void CodeGenFunction::EmitBranchToCounterBlock(
 /// statement) to the specified blocks.  Based on the condition, this might try
 /// to simplify the codegen of the conditional based on the branch.
 /// \param LH The value of the likelihood attribute on the True branch.
-void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
-                                           llvm::BasicBlock *TrueBlock,
-                                           llvm::BasicBlock *FalseBlock,
-                                           uint64_t TrueCount,
-                                           Stmt::Likelihood LH) {
+/// \param ConditionalOp Used by MC/DC code coverage to track the result of the
+/// ConditionalOperator (ternary) through a recursive call for the operator's
+/// LHS and RHS nodes.
+void CodeGenFunction::EmitBranchOnBoolExpr(
+    const Expr *Cond, llvm::BasicBlock *TrueBlock, llvm::BasicBlock *FalseBlock,
+    uint64_t TrueCount, Stmt::Likelihood LH, const Expr *ConditionalOp) {
   Cond = Cond->IgnoreParens();
 
   if (const BinaryOperator *CondBOp = dyn_cast<BinaryOperator>(Cond)) {
-
     // Handle X && Y in a condition.
     if (CondBOp->getOpcode() == BO_LAnd) {
+      MCDCLogOpStack.push_back(CondBOp);
+
       // If we have "1 && X", simplify the code.  "0 && X" would have constant
       // folded if the case was simple enough.
       bool ConstantBool = false;
       if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
           ConstantBool) {
         // br(1 && X) -> br(X).
         incrementProfileCounter(CondBOp);
-        return EmitBranchToCounterBlock(CondBOp->getRHS(), BO_LAnd, TrueBlock,
-                                        FalseBlock, TrueCount, LH);
+        EmitBranchToCounterBlock(CondBOp->getRHS(), BO_LAnd, TrueBlock,
+                                 FalseBlock, TrueCount, LH);
+        MCDCLogOpStack.pop_back();
+        return;
       }
 
       // If we have "X && 1", simplify the code to use an uncond branch.
       // "X && 0" would have been constant folded to 0.
       if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
           ConstantBool) {
         // br(X && 1) -> br(X).
-        return EmitBranchToCounterBlock(CondBOp->getLHS(), BO_LAnd, TrueBlock,
-                                        FalseBlock, TrueCount, LH, CondBOp);
+        EmitBranchToCounterBlock(CondBOp->getLHS(), BO_LAnd, TrueBlock,
+                                 FalseBlock, TrueCount, LH, CondBOp);
+        MCDCLogOpStack.pop_back();
+        return;
       }
 
       // Emit the LHS as a conditional.  If the LHS conditional is false, we
@@ -1774,31 +1792,36 @@ void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
       EmitBranchToCounterBlock(CondBOp->getRHS(), BO_LAnd, TrueBlock,
                                FalseBlock, TrueCount, LH);
       eval.end(*this);
-
+      MCDCLogOpStack.pop_back();
       return;
     }
 
     if (CondBOp->getOpcode() == BO_LOr) {
+      MCDCLogOpStack.push_back(CondBOp);
+
       // If we have "0 || X", simplify the code.  "1 || X" would have constant
       // folded if the case was simple enough.
       bool ConstantBool = false;
       if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
           !ConstantBool) {
         // br(0 || X) -> br(X).
         incrementProfileCounter(CondBOp);
-        return EmitBranchToCounterBlock(CondBOp->getRHS(), BO_LOr, TrueBlock,
-                                        FalseBlock, TrueCount, LH);
+        EmitBranchToCounterBlock(CondBOp->getRHS(), BO_LOr, TrueBlock,
+                                 FalseBlock, TrueCount, LH);
+        MCDCLogOpStack.pop_back();
+        return;
       }
 
       // If we have "X || 0", simplify the code to use an uncond branch.
       // "X || 1" would have been constant folded to 1.
       if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
           !ConstantBool) {
         // br(X || 0) -> br(X).
-        return EmitBranchToCounterBlock(CondBOp->getLHS(), BO_LOr, TrueBlock,
-                                        FalseBlock, TrueCount, LH, CondBOp);
+        EmitBranchToCounterBlock(CondBOp->getLHS(), BO_LOr, TrueBlock,
+                                 FalseBlock, TrueCount, LH, CondBOp);
+        MCDCLogOpStack.pop_back();
+        return;
       }
-
       // Emit the LHS as a conditional.  If the LHS conditional is true, we
       // want to jump to the TrueBlock.
       llvm::BasicBlock *LHSFalse = createBasicBlock("lor.lhs.false");
@@ -1829,14 +1852,20 @@ void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
                                RHSCount, LH);
 
       eval.end(*this);
-
+      MCDCLogOpStack.pop_back();
       return;
     }
   }
 
   if (const UnaryOperator *CondUOp = dyn_cast<UnaryOperator>(Cond)) {
     // br(!x, t, f) -> br(x, f, t)
-    if (CondUOp->getOpcode() == UO_LNot) {
+    // Avoid doing this optimization when instrumenting a condition for MC/DC.
+    // LNot is taken as part of the condition for simplicity, and changing its
+    // sense negatively impacts test vector tracking.
+    bool MCDCCondition = CGM.getCodeGenOpts().hasProfileClangInstr() &&
+                         CGM.getCodeGenOpts().MCDCCoverage &&
+                         isInstrumentedCondition(Cond);
+    if (CondUOp->getOpcode() == UO_LNot && !MCDCCondition) {
       // Negate the count.
       uint64_t FalseCount = getCurrentProfileCount() - TrueCount;
       // The values of the enum are chosen to make this negation possible.
@@ -1876,14 +1905,14 @@ void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
     {
       ApplyDebugLocation DL(*this, Cond);
       EmitBranchOnBoolExpr(CondOp->getLHS(), TrueBlock, FalseBlock,
-                           LHSScaledTrueCount, LH);
+                           LHSScaledTrueCount, LH, CondOp);
     }
     cond.end(*this);
 
     cond.begin(*this);
     EmitBlock(RHSBlock);
     EmitBranchOnBoolExpr(CondOp->getRHS(), TrueBlock, FalseBlock,
-                         TrueCount - LHSScaledTrueCount, LH);
+                         TrueCount - LHSScaledTrueCount, LH, CondOp);
     cond.end(*this);
 
     return;
@@ -1906,6 +1935,21 @@ void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
     CondV = EvaluateExprAsBool(Cond);
   }
 
+  // If not at the top of the logical operator nest, update MCDC temp with the
+  // boolean result of the evaluated condition.
+  if (!MCDCLogOpStack.empty()) {
+    const Expr *MCDCBaseExpr = Cond;
+    // When a nested ConditionalOperator (ternary) is encountered in a boolean
+    // expression, MC/DC tracks the result of the ternary, and this is tied to
+    // the ConditionalOperator expression and not the ternary's LHS or RHS. If
+    // this is the case, the ConditionalOperator expression is passed through
+    // the ConditionalOp parameter and then used as the MCDC base expression.
+    if (ConditionalOp)
+      MCDCBaseExpr = ConditionalOp;
+
+    maybeUpdateMCDCCondBitmap(MCDCBaseExpr, CondV);
+  }
+
   llvm::MDNode *Weights = nullptr;
   llvm::MDNode *Unpredictable = nullptr;
 

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
@@ -287,6 +287,9 @@ class CodeGenFunction : public CodeGenTypeCache {
   /// nest would extend.
   SmallVector<llvm::CanonicalLoopInfo *, 4> OMPLoopNestStack;
 
+  /// Stack to track the Logical Operator recursion nest for MC/DC.
+  SmallVector<const BinaryOperator *, 16> MCDCLogOpStack;
+
   /// Number of nested loop to be consumed by the last surrounding
   /// loop-associated directive.
   int ExpectedOMPLoopDepth = 0;
@@ -1521,6 +1524,9 @@ class CodeGenFunction : public CodeGenTypeCache {
 
   CodeGenPGO PGO;
 
+  /// Bitmap used by MC/DC to track condition outcomes of a boolean expression.
+  Address MCDCCondBitmapAddr = Address::invalid();
+
   /// Calculate branch weights appropriate for PGO data
   llvm::MDNode *createProfileWeights(uint64_t TrueCount,
                                      uint64_t FalseCount) const;
@@ -1539,6 +1545,52 @@ class CodeGenFunction : public CodeGenTypeCache {
     PGO.setCurrentStmt(S);
   }
 
+  bool isMCDCCoverageEnabled() const {
+    return (CGM.getCodeGenOpts().hasProfileClangInstr() &&
+            CGM.getCodeGenOpts().MCDCCoverage &&
+            !CurFn->hasFnAttribute(llvm::Attribute::NoProfile));
+  }
+
+  /// Allocate a temp value on the stack that MCDC can use to track condition
+  /// results.
+  void maybeCreateMCDCCondBitmap() {
+    if (isMCDCCoverageEnabled()) {
+      PGO.emitMCDCParameters(Builder);
+      MCDCCondBitmapAddr =
+          CreateIRTemp(getContext().UnsignedIntTy, "mcdc.addr");
+    }
+  }
+
+  bool isBinaryLogicalOp(const Expr *E) const {
+    const BinaryOperator *BOp = dyn_cast<BinaryOperator>(E->IgnoreParens());
+    return (BOp && BOp->isLogicalOp());
+  }
+
+  /// Zero-init the MCDC temp value.
+  void maybeResetMCDCCondBitmap(const Expr *E) {
+    if (isMCDCCoverageEnabled() && isBinaryLogicalOp(E)) {
+      PGO.emitMCDCCondBitmapReset(Builder, E, MCDCCondBitmapAddr);
+      PGO.setCurrentStmt(E);
+    }
+  }
+
+  /// Increment the profiler's counter for the given expression by \p StepV.
+  /// If \p StepV is null, the default increment is 1.
+  void maybeUpdateMCDCTestVectorBitmap(const Expr *E) {
+    if (isMCDCCoverageEnabled() && isBinaryLogicalOp(E)) {
+      PGO.emitMCDCTestVectorBitmapUpdate(Builder, E, MCDCCondBitmapAddr);
+      PGO.setCurrentStmt(E);
+    }
+  }
+
+  /// Update the MCDC temp value with the condition's evaluated result.
+  void maybeUpdateMCDCCondBitmap(const Expr *E, llvm::Value *Val) {
+    if (isMCDCCoverageEnabled()) {
+      PGO.emitMCDCCondBitmapUpdate(Builder, E, MCDCCondBitmapAddr, Val);
+      PGO.setCurrentStmt(E);
+    }
+  }
+
   /// Get the profiler's count for the given statement.
   uint64_t getProfileCount(const Stmt *S) {
     return PGO.getStmtCount(S).value_or(0);
@@ -4626,6 +4678,9 @@ class CodeGenFunction : public CodeGenTypeCache {
   bool ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APSInt &Result,
                                     bool AllowLabels = false);
 
+  /// Ignore parentheses and logical-NOT to track conditions consistently.
+  static const Expr *stripCond(const Expr *C);
+
   /// isInstrumentedCondition - Determine whether the given condition is an
   /// instrumentable condition (i.e. no "&&" or "||").
   static bool isInstrumentedCondition(const Expr *C);
@@ -4648,7 +4703,8 @@ class CodeGenFunction : public CodeGenTypeCache {
   /// evaluate to true based on PGO data.
   void EmitBranchOnBoolExpr(const Expr *Cond, llvm::BasicBlock *TrueBlock,
                             llvm::BasicBlock *FalseBlock, uint64_t TrueCount,
-                            Stmt::Likelihood LH = Stmt::LH_None);
+                            Stmt::Likelihood LH = Stmt::LH_None,
+                            const Expr *ConditionalOp = nullptr);
 
   /// Given an assignment `*LHS = RHS`, emit a test that checks if \p RHS is
   /// nonnull, if \p LHS is marked _Nonnull.

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -4869,6 +4869,10 @@ CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, llvm::Type *Ty,
         isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
       GV->setSection(".cp.rodata");
 
+    // Handle code model attribute
+    if (const auto *CMA = D->getAttr<CodeModelAttr>())
+      GV->setCodeModel(CMA->getModel());
+
     // Check if we a have a const declaration with an initializer, we may be
     // able to emit it as available_externally to expose it's value to the
     // optimizer.

diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp
@@ -161,13 +161,24 @@ struct MapRegionCounters : public RecursiveASTVisitor<MapRegionCounters> {
   PGOHash Hash;
   /// The map of statements to counters.
   llvm::DenseMap<const Stmt *, unsigned> &CounterMap;
+  /// The next bitmap byte index to assign.
+  unsigned NextMCDCBitmapIdx;
+  /// The map of statements to MC/DC bitmap coverage objects.
+  llvm::DenseMap<const Stmt *, unsigned> &MCDCBitmapMap;
+  /// Maximum number of supported MC/DC conditions in a boolean expression.
+  unsigned MCDCMaxCond;
   /// The profile version.
   uint64_t ProfileVersion;
+  /// Diagnostics Engine used to report warnings.
+  DiagnosticsEngine &Diag;
 
   MapRegionCounters(PGOHashVersion HashVersion, uint64_t ProfileVersion,
-                    llvm::DenseMap<const Stmt *, unsigned> &CounterMap)
+                    llvm::DenseMap<const Stmt *, unsigned> &CounterMap,
+                    llvm::DenseMap<const Stmt *, unsigned> &MCDCBitmapMap,
+                    unsigned MCDCMaxCond, DiagnosticsEngine &Diag)
       : NextCounter(0), Hash(HashVersion), CounterMap(CounterMap),
-        ProfileVersion(ProfileVersion) {}
+        NextMCDCBitmapIdx(0), MCDCBitmapMap(MCDCBitmapMap),
+        MCDCMaxCond(MCDCMaxCond), ProfileVersion(ProfileVersion), Diag(Diag) {}
 
   // Blocks and lambdas are handled as separate functions, so we need not
   // traverse them in the parent context.
@@ -207,15 +218,126 @@ struct MapRegionCounters : public RecursiveASTVisitor<MapRegionCounters> {
     return Type;
   }
 
+  /// The following stacks are used with dataTraverseStmtPre() and
+  /// dataTraverseStmtPost() to track the depth of nested logical operators in a
+  /// boolean expression in a function.  The ultimate purpose is to keep track
+  /// of the number of leaf-level conditions in the boolean expression so that a
+  /// profile bitmap can be allocated based on that number.
+  ///
+  /// The stacks are also used to find error cases and notify the user.  A
+  /// standard logical operator nest for a boolean expression could be in a form
+  /// similar to this: "x = a && b && c && (d || f)"
+  unsigned NumCond = 0;
+  bool SplitNestedLogicalOp = false;
+  SmallVector<const Stmt *, 16> NonLogOpStack;
+  SmallVector<const BinaryOperator *, 16> LogOpStack;
+
+  // Hook: dataTraverseStmtPre() is invoked prior to visiting an AST Stmt node.
+  bool dataTraverseStmtPre(Stmt *S) {
+    /// If MC/DC is not enabled, MCDCMaxCond will be set to 0. Do nothing.
+    if (MCDCMaxCond == 0)
+      return true;
+
+    /// At the top of the logical operator nest, reset the number of conditions.
+    if (LogOpStack.empty())
+      NumCond = 0;
+
+    if (const Expr *E = dyn_cast<Expr>(S)) {
+      const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E->IgnoreParens());
+      if (BinOp && BinOp->isLogicalOp()) {
+        /// Check for "split-nested" logical operators. This happens when a new
+        /// boolean expression logical-op nest is encountered within an existing
+        /// boolean expression, separated by a non-logical operator.  For
+        /// example, in "x = (a && b && c && foo(d && f))", the "d && f" case
+        /// starts a new boolean expression that is separated from the other
+        /// conditions by the operator foo(). Split-nested cases are not
+        /// supported by MC/DC.
+        SplitNestedLogicalOp = SplitNestedLogicalOp || !NonLogOpStack.empty();
+
+        LogOpStack.push_back(BinOp);
+        return true;
+      }
+    }
+
+    /// Keep track of non-logical operators. These are OK as long as we don't
+    /// encounter a new logical operator after seeing one.
+    if (!LogOpStack.empty())
+      NonLogOpStack.push_back(S);
+
+    return true;
+  }
+
+  // Hook: dataTraverseStmtPost() is invoked by the AST visitor after visiting
+  // an AST Stmt node.  MC/DC will use it to to signal when the top of a
+  // logical operation (boolean expression) nest is encountered.
+  bool dataTraverseStmtPost(Stmt *S) {
+    /// If MC/DC is not enabled, MCDCMaxCond will be set to 0. Do nothing.
+    if (MCDCMaxCond == 0)
+      return true;
+
+    if (const Expr *E = dyn_cast<Expr>(S)) {
+      const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E->IgnoreParens());
+      if (BinOp && BinOp->isLogicalOp()) {
+        assert(LogOpStack.back() == BinOp);
+        LogOpStack.pop_back();
+
+        /// At the top of logical operator nest:
+        if (LogOpStack.empty()) {
+          /// Was the "split-nested" logical operator case encountered?
+          if (SplitNestedLogicalOp) {
+            unsigned DiagID = Diag.getCustomDiagID(
+                DiagnosticsEngine::Warning,
+                "unsupported MC/DC boolean expression; "
+                "contains an operation with a nested boolean expression. "
+                "Expression will not be covered");
+            Diag.Report(S->getBeginLoc(), DiagID);
+            return false;
+          }
+
+          /// Was the maximum number of conditions encountered?
+          if (NumCond > MCDCMaxCond) {
+            unsigned DiagID = Diag.getCustomDiagID(
+                DiagnosticsEngine::Warning,
+                "unsupported MC/DC boolean expression; "
+                "number of conditions (%0) exceeds max (%1). "
+                "Expression will not be covered");
+            Diag.Report(S->getBeginLoc(), DiagID) << NumCond << MCDCMaxCond;
+            return false;
+          }
+
+          // Otherwise, allocate the number of bytes required for the bitmap
+          // based on the number of conditions. Must be at least 1-byte long.
+          MCDCBitmapMap[BinOp] = NextMCDCBitmapIdx;
+          unsigned SizeInBits = std::max<unsigned>(1L << NumCond, CHAR_BIT);
+          NextMCDCBitmapIdx += SizeInBits / CHAR_BIT;
+        }
+        return true;
+      }
+    }
+
+    if (!LogOpStack.empty())
+      NonLogOpStack.pop_back();
+
+    return true;
+  }
+
   /// The RHS of all logical operators gets a fresh counter in order to count
   /// how many times the RHS evaluates to true or false, depending on the
   /// semantics of the operator. This is only valid for ">= v7" of the profile
-  /// version so that we facilitate backward compatibility.
+  /// version so that we facilitate backward compatibility. In addition, in
+  /// order to use MC/DC, count the number of total LHS and RHS conditions.
   bool VisitBinaryOperator(BinaryOperator *S) {
-    if (ProfileVersion >= llvm::IndexedInstrProf::Version7)
-      if (S->isLogicalOp() &&
-          CodeGenFunction::isInstrumentedCondition(S->getRHS()))
-        CounterMap[S->getRHS()] = NextCounter++;
+    if (S->isLogicalOp()) {
+      if (CodeGenFunction::isInstrumentedCondition(S->getLHS()))
+        NumCond++;
+
+      if (CodeGenFunction::isInstrumentedCondition(S->getRHS())) {
+        if (ProfileVersion >= llvm::IndexedInstrProf::Version7)
+          CounterMap[S->getRHS()] = NextCounter++;
+
+        NumCond++;
+      }
+    }
     return Base::VisitBinaryOperator(S);
   }
 
@@ -851,8 +973,22 @@ void CodeGenPGO::mapRegionCounters(const Decl *D) {
     ProfileVersion = PGOReader->getVersion();
   }
 
+  // If MC/DC is enabled, set the MaxConditions to a preset value. Otherwise,
+  // set it to zero. This value impacts the number of conditions accepted in a
+  // given boolean expression, which impacts the size of the bitmap used to
+  // track test vector execution for that boolean expression.  Because the
+  // bitmap scales exponentially (2^n) based on the number of conditions seen,
+  // the maximum value is hard-coded at 6 conditions, which is more than enough
+  // for most embedded applications. Setting a maximum value prevents the
+  // bitmap footprint from growing too large without the user's knowledge. In
+  // the future, this value could be adjusted with a command-line option.
+  unsigned MCDCMaxConditions = (CGM.getCodeGenOpts().MCDCCoverage) ? 6 : 0;
+
   RegionCounterMap.reset(new llvm::DenseMap<const Stmt *, unsigned>);
-  MapRegionCounters Walker(HashVersion, ProfileVersion, *RegionCounterMap);
+  RegionMCDCBitmapMap.reset(new llvm::DenseMap<const Stmt *, unsigned>);
+  MapRegionCounters Walker(HashVersion, ProfileVersion, *RegionCounterMap,
+                           *RegionMCDCBitmapMap, MCDCMaxConditions,
+                           CGM.getDiags());
   if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
     Walker.TraverseDecl(const_cast<FunctionDecl *>(FD));
   else if (const ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(D))
@@ -863,6 +999,7 @@ void CodeGenPGO::mapRegionCounters(const Decl *D) {
     Walker.TraverseDecl(const_cast<CapturedDecl *>(CD));
   assert(Walker.NextCounter > 0 && "no entry counter mapped for decl");
   NumRegionCounters = Walker.NextCounter;
+  MCDCBitmapBytes = Walker.NextMCDCBitmapIdx;
   FunctionHash = Walker.Hash.finalize();
 }
 
@@ -894,9 +1031,11 @@ void CodeGenPGO::emitCounterRegionMapping(const Decl *D) {
 
   std::string CoverageMapping;
   llvm::raw_string_ostream OS(CoverageMapping);
-  CoverageMappingGen MappingGen(*CGM.getCoverageMapping(),
-                                CGM.getContext().getSourceManager(),
-                                CGM.getLangOpts(), RegionCounterMap.get());
+  RegionCondIDMap.reset(new llvm::DenseMap<const Stmt *, unsigned>);
+  CoverageMappingGen MappingGen(
+      *CGM.getCoverageMapping(), CGM.getContext().getSourceManager(),
+      CGM.getLangOpts(), RegionCounterMap.get(), RegionMCDCBitmapMap.get(),
+      RegionCondIDMap.get());
   MappingGen.emitCounterMapping(D, OS);
   OS.flush();
 
@@ -972,6 +1111,108 @@ void CodeGenPGO::emitCounterIncrement(CGBuilderTy &Builder, const Stmt *S,
         ArrayRef(Args));
 }
 
+bool CodeGenPGO::canEmitMCDCCoverage(const CGBuilderTy &Builder) {
+  return (CGM.getCodeGenOpts().hasProfileClangInstr() &&
+          CGM.getCodeGenOpts().MCDCCoverage && Builder.GetInsertBlock());
+}
+
+void CodeGenPGO::emitMCDCParameters(CGBuilderTy &Builder) {
+  if (!canEmitMCDCCoverage(Builder) || !RegionMCDCBitmapMap)
+    return;
+
+  auto *I8PtrTy = llvm::PointerType::getUnqual(CGM.getLLVMContext());
+
+  // Emit intrinsic representing MCDC bitmap parameters at function entry.
+  // This is used by the instrumentation pass, but it isn't actually lowered to
+  // anything.
+  llvm::Value *Args[3] = {llvm::ConstantExpr::getBitCast(FuncNameVar, I8PtrTy),
+                          Builder.getInt64(FunctionHash),
+                          Builder.getInt32(MCDCBitmapBytes)};
+  Builder.CreateCall(
+      CGM.getIntrinsic(llvm::Intrinsic::instrprof_mcdc_parameters), Args);
+}
+
+void CodeGenPGO::emitMCDCTestVectorBitmapUpdate(CGBuilderTy &Builder,
+                                                const Expr *S,
+                                                Address MCDCCondBitmapAddr) {
+  if (!canEmitMCDCCoverage(Builder) || !RegionMCDCBitmapMap)
+    return;
+
+  S = S->IgnoreParens();
+
+  auto ExprMCDCBitmapMapIterator = RegionMCDCBitmapMap->find(S);
+  if (ExprMCDCBitmapMapIterator == RegionMCDCBitmapMap->end())
+    return;
+
+  // Extract the ID of the global bitmap associated with this expression.
+  unsigned MCDCTestVectorBitmapID = ExprMCDCBitmapMapIterator->second;
+  auto *I8PtrTy = llvm::PointerType::getUnqual(CGM.getLLVMContext());
+
+  // Emit intrinsic responsible for updating the global bitmap corresponding to
+  // a boolean expression. The index being set is based on the value loaded
+  // from a pointer to a dedicated temporary value on the stack that is itself
+  // updated via emitMCDCCondBitmapReset() and emitMCDCCondBitmapUpdate(). The
+  // index represents an executed test vector.
+  llvm::Value *Args[5] = {llvm::ConstantExpr::getBitCast(FuncNameVar, I8PtrTy),
+                          Builder.getInt64(FunctionHash),
+                          Builder.getInt32(MCDCBitmapBytes),
+                          Builder.getInt32(MCDCTestVectorBitmapID),
+                          MCDCCondBitmapAddr.getPointer()};
+  Builder.CreateCall(
+      CGM.getIntrinsic(llvm::Intrinsic::instrprof_mcdc_tvbitmap_update), Args);
+}
+
+void CodeGenPGO::emitMCDCCondBitmapReset(CGBuilderTy &Builder, const Expr *S,
+                                         Address MCDCCondBitmapAddr) {
+  if (!canEmitMCDCCoverage(Builder) || !RegionMCDCBitmapMap)
+    return;
+
+  S = S->IgnoreParens();
+
+  if (RegionMCDCBitmapMap->find(S) == RegionMCDCBitmapMap->end())
+    return;
+
+  // Emit intrinsic that resets a dedicated temporary value on the stack to 0.
+  Builder.CreateStore(Builder.getInt32(0), MCDCCondBitmapAddr);
+}
+
+void CodeGenPGO::emitMCDCCondBitmapUpdate(CGBuilderTy &Builder, const Expr *S,
+                                          Address MCDCCondBitmapAddr,
+                                          llvm::Value *Val) {
+  if (!canEmitMCDCCoverage(Builder) || !RegionCondIDMap)
+    return;
+
+  // Even though, for simplicity, parentheses and unary logical-NOT operators
+  // are considered part of their underlying condition for both MC/DC and
+  // branch coverage, the condition IDs themselves are assigned and tracked
+  // using the underlying condition itself.  This is done solely for
+  // consistency since parentheses and logical-NOTs are ignored when checking
+  // whether the condition is actually an instrumentable condition. This can
+  // also make debugging a bit easier.
+  S = CodeGenFunction::stripCond(S);
+
+  auto ExprMCDCConditionIDMapIterator = RegionCondIDMap->find(S);
+  if (ExprMCDCConditionIDMapIterator == RegionCondIDMap->end())
+    return;
+
+  // Extract the ID of the condition we are setting in the bitmap.
+  unsigned CondID = ExprMCDCConditionIDMapIterator->second;
+  assert(CondID > 0 && "Condition has no ID!");
+
+  auto *I8PtrTy = llvm::PointerType::getUnqual(CGM.getLLVMContext());
+
+  // Emit intrinsic that updates a dedicated temporary value on the stack after
+  // a condition is evaluated. After the set of conditions has been updated,
+  // the resulting value is used to update the boolean expression's bitmap.
+  llvm::Value *Args[5] = {llvm::ConstantExpr::getBitCast(FuncNameVar, I8PtrTy),
+                          Builder.getInt64(FunctionHash),
+                          Builder.getInt32(CondID - 1),
+                          MCDCCondBitmapAddr.getPointer(), Val};
+  Builder.CreateCall(
+      CGM.getIntrinsic(llvm::Intrinsic::instrprof_mcdc_condbitmap_update),
+      Args);
+}
+
 void CodeGenPGO::setValueProfilingFlag(llvm::Module &M) {
   if (CGM.getCodeGenOpts().hasProfileClangInstr())
     M.addModuleFlag(llvm::Module::Warning, "EnableValueProfiling",

diff --git a/clang/lib/CodeGen/CodeGenPGO.h b/clang/lib/CodeGen/CodeGenPGO.h
@@ -33,8 +33,11 @@ class CodeGenPGO {
 
   std::array <unsigned, llvm::IPVK_Last + 1> NumValueSites;
   unsigned NumRegionCounters;
+  unsigned MCDCBitmapBytes;
   uint64_t FunctionHash;
   std::unique_ptr<llvm::DenseMap<const Stmt *, unsigned>> RegionCounterMap;
+  std::unique_ptr<llvm::DenseMap<const Stmt *, unsigned>> RegionMCDCBitmapMap;
+  std::unique_ptr<llvm::DenseMap<const Stmt *, unsigned>> RegionCondIDMap;
   std::unique_ptr<llvm::DenseMap<const Stmt *, uint64_t>> StmtCountMap;
   std::unique_ptr<llvm::InstrProfRecord> ProfRecord;
   std::vector<uint64_t> RegionCounts;
@@ -43,7 +46,8 @@ class CodeGenPGO {
 public:
   CodeGenPGO(CodeGenModule &CGModule)
       : CGM(CGModule), FuncNameVar(nullptr), NumValueSites({{0}}),
-        NumRegionCounters(0), FunctionHash(0), CurrentRegionCount(0) {}
+        NumRegionCounters(0), MCDCBitmapBytes(0), FunctionHash(0),
+        CurrentRegionCount(0) {}
 
   /// Whether or not we have PGO region data for the current function. This is
   /// false both when we have no data at all and when our data has been
@@ -103,10 +107,18 @@ class CodeGenPGO {
                         bool IsInMainFile);
   bool skipRegionMappingForDecl(const Decl *D);
   void emitCounterRegionMapping(const Decl *D);
+  bool canEmitMCDCCoverage(const CGBuilderTy &Builder);
 
 public:
   void emitCounterIncrement(CGBuilderTy &Builder, const Stmt *S,
                             llvm::Value *StepV);
+  void emitMCDCTestVectorBitmapUpdate(CGBuilderTy &Builder, const Expr *S,
+                                      Address MCDCCondBitmapAddr);
+  void emitMCDCParameters(CGBuilderTy &Builder);
+  void emitMCDCCondBitmapReset(CGBuilderTy &Builder, const Expr *S,
+                               Address MCDCCondBitmapAddr);
+  void emitMCDCCondBitmapUpdate(CGBuilderTy &Builder, const Expr *S,
+                                Address MCDCCondBitmapAddr, llvm::Value *Val);
 
   /// Return the region count for the counter at the given index.
   uint64_t getRegionCount(const Stmt *S) {