diff --git a/clang/include/clang/AST/OpenMPClause.h b/clang/include/clang/AST/OpenMPClause.h
--- a/clang/include/clang/AST/OpenMPClause.h
+++ b/clang/include/clang/AST/OpenMPClause.h
@@ -7917,6 +7917,12 @@
   /// Start location of the kind in source code.
   SourceLocation KindKwLoc;
 
+  /// A modifier for order clause
+  OpenMPOrderClauseModifier Modifier = OMPC_ORDER_MODIFIER_unknown;
+
+  /// Start location of the modifier in source code.
+  SourceLocation ModifierKwLoc;
+
   /// Set kind of the clause.
   ///
   /// \param K Argument of clause.
@@ -7927,6 +7933,16 @@
   /// \param KLoc Argument location.
   void setKindKwLoc(SourceLocation KLoc) { KindKwLoc = KLoc; }
 
+  /// Set modifier of the clause.
+  ///
+  /// \param M Argument of clause.
+  void setModifier(OpenMPOrderClauseModifier M) { Modifier = M; }
+
+  /// Set modifier location.
+  ///
+  /// \param MLoc Modifier keyword location.
+  void setModifierKwLoc(SourceLocation MLoc) { ModifierKwLoc = MLoc; }
+
 public:
   /// Build 'order' clause with argument \p A ('concurrent').
   ///
@@ -7935,11 +7951,15 @@
   /// \param StartLoc Starting location of the clause.
   /// \param LParenLoc Location of '('.
   /// \param EndLoc Ending location of the clause.
+  /// \param Modifier The modifier applied to 'order' clause.
+  /// \param MLoc Location of the modifier
   OMPOrderClause(OpenMPOrderClauseKind A, SourceLocation ALoc,
                  SourceLocation StartLoc, SourceLocation LParenLoc,
-                 SourceLocation EndLoc)
+                 SourceLocation EndLoc, OpenMPOrderClauseModifier M,
+                 SourceLocation MLoc)
       : OMPClause(llvm::omp::OMPC_order, StartLoc, EndLoc),
-        LParenLoc(LParenLoc), Kind(A), KindKwLoc(ALoc) {}
+        LParenLoc(LParenLoc), Kind(A), KindKwLoc(ALoc), Modifier(M),
+        ModifierKwLoc(MLoc) {}
 
   /// Build an empty clause.
   OMPOrderClause()
@@ -7957,6 +7977,12 @@
   /// Returns location of clause kind.
   SourceLocation getKindKwLoc() const { return KindKwLoc; }
 
+  /// Returns Modifier of the clause.
+  OpenMPOrderClauseModifier getModifier() const { return Modifier; }
+
+  /// Returns location of clause modifier.
+  SourceLocation getModifierKwLoc() const { return ModifierKwLoc; }
+
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10443,6 +10443,10 @@
   "a reduction list item with incomplete type %0">;
 def err_omp_unexpected_clause_value : Error<
   "expected %0 in OpenMP clause '%1'">;
+def err_omp_unexpected_call_to_omp_runtime_api
+    : Error<"calls to OpenMP runtime API are not allowed within a region that "
+            "corresponds to a construct with an order clause that specifies "
+            "concurrent">;
 def err_omp_expected_var_name_member_expr : Error<
   "expected variable name%select{| or data member of current class}0">;
 def err_omp_expected_var_name_member_expr_with_type : Error<
@@ -10637,6 +10641,9 @@
   "OpenMP constructs may not be nested inside a simd region%select{| except for ordered simd, simd, scan, or atomic directive}0">;
 def err_omp_prohibited_region_atomic : Error<
   "OpenMP constructs may not be nested inside an atomic region">;
+def err_omp_prohibited_region_order
+    : Error<"construct '%0' not allowed in a region associated with a "
+            "directive with 'order' clause">;
 def err_omp_prohibited_region_critical_same_name : Error<
   "cannot nest 'critical' regions having the same name %0">;
 def note_omp_previous_critical_region : Note<
diff --git a/clang/include/clang/Basic/OpenMPKinds.h b/clang/include/clang/Basic/OpenMPKinds.h
--- a/clang/include/clang/Basic/OpenMPKinds.h
+++ b/clang/include/clang/Basic/OpenMPKinds.h
@@ -167,6 +167,14 @@
   OMPC_ORDER_unknown,
 };
 
+/// OpenMP modifiers for 'order' clause.
+enum OpenMPOrderClauseModifier {
+  OMPC_ORDER_MODIFIER_unknown = OMPC_ORDER_unknown,
+#define OPENMP_ORDER_MODIFIER(Name) OMPC_ORDER_MODIFIER_##Name,
+#include "clang/Basic/OpenMPKinds.def"
+  OMPC_ORDER_MODIFIER_last
+};
+
 /// Scheduling data for loop-based OpenMP directives.
 struct OpenMPScheduleTy final {
   OpenMPScheduleClauseKind Schedule = OMPC_SCHEDULE_unknown;
@@ -334,6 +342,13 @@
 void getOpenMPCaptureRegions(
     llvm::SmallVectorImpl<OpenMPDirectiveKind> &CaptureRegions,
     OpenMPDirectiveKind DKind);
+
+/// Checks if the specified directive is a combined construct for which
+/// the first construct is a parallel construct.
+/// \param DKind Specified directive.
+/// \return true - if the above condition is met for this directive
+/// otherwise - false.
+bool isOpenMPCombinedParallelADirective(OpenMPDirectiveKind DKind);
 }
 
 #endif
diff --git a/clang/include/clang/Basic/OpenMPKinds.def b/clang/include/clang/Basic/OpenMPKinds.def
--- a/clang/include/clang/Basic/OpenMPKinds.def
+++ b/clang/include/clang/Basic/OpenMPKinds.def
@@ -59,6 +59,9 @@
 #ifndef OPENMP_ORDER_KIND
 #define OPENMP_ORDER_KIND(Name)
 #endif
+#ifndef OPENMP_ORDER_MODIFIER
+#define OPENMP_ORDER_MODIFIER(Name)
+#endif
 #ifndef OPENMP_DEVICE_MODIFIER
 #define OPENMP_DEVICE_MODIFIER(Name)
 #endif
@@ -173,6 +176,10 @@
 // Type of the 'order' clause.
 OPENMP_ORDER_KIND(concurrent)
 
+// Modifiers for the 'order' clause.
+OPENMP_ORDER_MODIFIER(reproducible)
+OPENMP_ORDER_MODIFIER(unconstrained)
+
 // Modifiers for 'reduction' clause.
 OPENMP_REDUCTION_MODIFIER(default)
 OPENMP_REDUCTION_MODIFIER(inscan)
@@ -200,6 +207,7 @@
 #undef OPENMP_REDUCTION_MODIFIER
 #undef OPENMP_DEVICE_MODIFIER
 #undef OPENMP_ORDER_KIND
+#undef OPENMP_ORDER_MODIFIER
 #undef OPENMP_LASTPRIVATE_KIND
 #undef OPENMP_DEVICE_TYPE_KIND
 #undef OPENMP_LINEAR_KIND
diff --git a/clang/include/clang/Sema/Scope.h b/clang/include/clang/Sema/Scope.h
--- a/clang/include/clang/Sema/Scope.h
+++ b/clang/include/clang/Sema/Scope.h
@@ -140,6 +140,10 @@
     /// parsed. If such a scope is a ContinueScope, it's invalid to jump to the
     /// continue block from here.
     ConditionVarScope = 0x2000000,
+
+    /// This is a scope of some OpenMP directive with
+    /// order clause which specifies concurrent
+    OpenMPOrderClauseScope = 0x4000000,
   };
 
 private:
@@ -488,6 +492,12 @@
     return P && P->isOpenMPLoopDirectiveScope();
   }
 
+  /// Determine whether this scope is some OpenMP directive with
+  /// order clause which specifies concurrent scope.
+  bool isOpenMPOrderClauseScope() const {
+    return getFlags() & Scope::OpenMPOrderClauseScope;
+  }
+
   /// Determine whether this scope is a while/do/for statement, which can have
   /// continue statements embedded into it.
   bool isContinueScope() const {
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -11724,10 +11724,11 @@
                                        SourceLocation LParenLoc,
                                        SourceLocation EndLoc);
   /// Called on well-formed 'order' clause.
-  OMPClause *ActOnOpenMPOrderClause(OpenMPOrderClauseKind Kind,
-                                    SourceLocation KindLoc,
+  OMPClause *ActOnOpenMPOrderClause(OpenMPOrderClauseModifier Modifier,
+                                    OpenMPOrderClauseKind Kind,
                                     SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
+                                    SourceLocation MLoc, SourceLocation KindLoc,
                                     SourceLocation EndLoc);
   /// Called on well-formed 'update' clause.
   OMPClause *ActOnOpenMPUpdateClause(OpenMPDependClauseKind Kind,
diff --git a/clang/lib/AST/OpenMPClause.cpp b/clang/lib/AST/OpenMPClause.cpp
--- a/clang/lib/AST/OpenMPClause.cpp
+++ b/clang/lib/AST/OpenMPClause.cpp
@@ -2370,8 +2370,12 @@
 }
 
 void OMPClausePrinter::VisitOMPOrderClause(OMPOrderClause *Node) {
-  OS << "order(" << getOpenMPSimpleClauseTypeName(OMPC_order, Node->getKind())
-     << ")";
+  OS << "order(";
+  if (Node->getModifier() != OMPC_ORDER_MODIFIER_unknown) {
+    OS << getOpenMPSimpleClauseTypeName(OMPC_order, Node->getModifier());
+    OS << ": ";
+  }
+  OS << getOpenMPSimpleClauseTypeName(OMPC_order, Node->getKind()) << ")";
 }
 
 void OMPClausePrinter::VisitOMPInclusiveClause(OMPInclusiveClause *Node) {
diff --git a/clang/lib/Basic/OpenMPKinds.cpp b/clang/lib/Basic/OpenMPKinds.cpp
--- a/clang/lib/Basic/OpenMPKinds.cpp
+++ b/clang/lib/Basic/OpenMPKinds.cpp
@@ -120,8 +120,11 @@
 #include "clang/Basic/OpenMPKinds.def"
         .Default(OMPC_LASTPRIVATE_unknown);
   case OMPC_order:
-    return llvm::StringSwitch<OpenMPOrderClauseKind>(Str)
-#define OPENMP_ORDER_KIND(Name) .Case(#Name, OMPC_ORDER_##Name)
+    return llvm::StringSwitch<unsigned>(Str)
+#define OPENMP_ORDER_KIND(Name)                                                \
+  .Case(#Name, static_cast<unsigned>(OMPC_ORDER_##Name))
+#define OPENMP_ORDER_MODIFIER(Name)                                            \
+  .Case(#Name, static_cast<unsigned>(OMPC_ORDER_MODIFIER_##Name))
 #include "clang/Basic/OpenMPKinds.def"
         .Default(OMPC_ORDER_unknown);
   case OMPC_update:
@@ -395,10 +398,14 @@
   case OMPC_order:
     switch (Type) {
     case OMPC_ORDER_unknown:
+    case OMPC_ORDER_MODIFIER_last:
       return "unknown";
 #define OPENMP_ORDER_KIND(Name)                                                \
-    case OMPC_ORDER_##Name:                                                    \
-      return #Name;
+  case OMPC_ORDER_##Name:                                                      \
+    return #Name;
+#define OPENMP_ORDER_MODIFIER(Name)                                            \
+  case OMPC_ORDER_MODIFIER_##Name:                                             \
+    return #Name;
 #include "clang/Basic/OpenMPKinds.def"
     }
     llvm_unreachable("Invalid OpenMP 'order' clause type");
@@ -714,6 +721,14 @@
   return DKind == OMPD_tile || DKind == OMPD_unroll;
 }
 
+bool clang::isOpenMPCombinedParallelADirective(OpenMPDirectiveKind DKind) {
+  return DKind == OMPD_parallel_for || DKind == OMPD_parallel_for_simd ||
+         DKind == OMPD_parallel_master ||
+         DKind == OMPD_parallel_master_taskloop ||
+         DKind == OMPD_parallel_master_taskloop_simd ||
+         DKind == OMPD_parallel_sections;
+}
+
 void clang::getOpenMPCaptureRegions(
     SmallVectorImpl<OpenMPDirectiveKind> &CaptureRegions,
     OpenMPDirectiveKind DKind) {
diff --git a/clang/lib/Parse/ParseOpenMP.cpp b/clang/lib/Parse/ParseOpenMP.cpp
--- a/clang/lib/Parse/ParseOpenMP.cpp
+++ b/clang/lib/Parse/ParseOpenMP.cpp
@@ -3240,7 +3240,6 @@
   case OMPC_atomic_default_mem_order:
   case OMPC_at:
   case OMPC_severity:
-  case OMPC_order:
   case OMPC_bind:
     // OpenMP [2.14.3.1, Restrictions]
     //  Only a single default clause may be specified on a parallel, task or
@@ -3255,7 +3254,7 @@
     //  At most one severity clause can appear on the directive
     // OpenMP 5.1, 2.11.7 loop Construct, Restrictions.
     // At most one bind clause can appear on a loop directive.
-    if (!FirstClause && CKind != OMPC_order) {
+    if (!FirstClause) {
       Diag(Tok, diag::err_omp_more_one_clause)
           << getOpenMPDirectiveName(DKind) << getOpenMPClauseName(CKind) << 0;
       ErrorFound = true;
@@ -3267,14 +3266,17 @@
   case OMPC_schedule:
   case OMPC_dist_schedule:
   case OMPC_defaultmap:
+  case OMPC_order:
     // OpenMP [2.7.1, Restrictions, p. 3]
     //  Only one schedule clause can appear on a loop directive.
     // OpenMP 4.5 [2.10.4, Restrictions, p. 106]
     //  At most one defaultmap clause can appear on the directive.
     // OpenMP 5.0 [2.12.5, target construct, Restrictions]
     //  At most one device clause can appear on the directive.
+    // OpenMP 5.1 [2.11.3, order clause, Restrictions]
+    //  At most one order clause may appear on a construct.
     if ((getLangOpts().OpenMP < 50 || CKind != OMPC_defaultmap) &&
-        !FirstClause) {
+        (CKind != OMPC_order || getLangOpts().OpenMP >= 51) && !FirstClause) {
       Diag(Tok, diag::err_omp_more_one_clause)
           << getOpenMPDirectiveName(DKind) << getOpenMPClauseName(CKind) << 0;
       ErrorFound = true;
@@ -3862,6 +3864,34 @@
       Arg.push_back(OMPC_DEFAULTMAP_unknown);
       KLoc.push_back(SourceLocation());
     }
+  } else if (Kind == OMPC_order) {
+    enum { Modifier, OrderKind, NumberOfElements };
+    Arg.resize(NumberOfElements);
+    KLoc.resize(NumberOfElements);
+    Arg[Modifier] = OMPC_ORDER_MODIFIER_unknown;
+    Arg[OrderKind] = OMPC_ORDER_unknown;
+    unsigned KindModifier = getOpenMPSimpleClauseType(
+        Kind, Tok.isAnnotation() ? "" : PP.getSpelling(Tok), getLangOpts());
+    if (KindModifier > OMPC_ORDER_unknown) {
+      // Parse 'modifier'
+      Arg[Modifier] = KindModifier;
+      KLoc[Modifier] = Tok.getLocation();
+      if (Tok.isNot(tok::r_paren) && Tok.isNot(tok::comma) &&
+          Tok.isNot(tok::annot_pragma_openmp_end))
+        ConsumeAnyToken();
+      // Parse ':'
+      if (Tok.is(tok::colon))
+        ConsumeAnyToken();
+      else
+        Diag(Tok, diag::warn_pragma_expected_colon) << "order modifier";
+      KindModifier = getOpenMPSimpleClauseType(
+          Kind, Tok.isAnnotation() ? "" : PP.getSpelling(Tok), getLangOpts());
+    }
+    Arg[OrderKind] = KindModifier;
+    KLoc[OrderKind] = Tok.getLocation();
+    if (Tok.isNot(tok::r_paren) && Tok.isNot(tok::comma) &&
+        Tok.isNot(tok::annot_pragma_openmp_end))
+      ConsumeAnyToken();
   } else if (Kind == OMPC_device) {
     // Only target executable directives support extended device construct.
     if (isOpenMPTargetExecutionDirective(DKind) && getLangOpts().OpenMP >= 50 &&
diff --git a/clang/lib/Sema/Scope.cpp b/clang/lib/Sema/Scope.cpp
--- a/clang/lib/Sema/Scope.cpp
+++ b/clang/lib/Sema/Scope.cpp
@@ -43,6 +43,9 @@
                   FunctionPrototypeScope | AtCatchScope | ObjCMethodScope)) ==
         0)
       Flags |= parent->getFlags() & OpenMPSimdDirectiveScope;
+    // transmit the parent's 'order' flag, if exists
+    if (parent->getFlags() & OpenMPOrderClauseScope)
+      Flags |= OpenMPOrderClauseScope;
   } else {
     Depth = 0;
     PrototypeDepth = 0;
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -173,6 +173,7 @@
     /// 'ordered' clause, the second one is true if the regions has 'ordered'
     /// clause, false otherwise.
     llvm::Optional<std::pair<const Expr *, OMPOrderedClause *>> OrderedRegion;
+    bool RegionHasOrderConcurrent = false;
     unsigned AssociatedLoops = 1;
     bool HasMutipleLoops = false;
     const Decl *PossiblyLoopCounter = nullptr;
@@ -865,6 +866,17 @@
         return Parent->OrderedRegion.value();
     return std::make_pair(nullptr, nullptr);
   }
+  /// Marks current region as having an 'order' clause.
+  void setRegionHasOrderConcurrent(bool HasOrderConcurrent) {
+    getTopOfStack().RegionHasOrderConcurrent = HasOrderConcurrent;
+  }
+  /// Returns true, if parent region is order (has associated
+  /// 'order' clause), false - otherwise.
+  bool isParentOrderConcurrent() const {
+    if (const SharingMapTy *Parent = getSecondOnStackOrNull())
+      return Parent->RegionHasOrderConcurrent;
+    return false;
+  }
   /// Marks current region as nowait (it has a 'nowait' clause).
   void setNowaitRegion(bool IsNowait = true) {
     getTopOfStack().NowaitRegion = IsNowait;
@@ -4943,6 +4955,14 @@
       ShouldBeInTeamsRegion,
       ShouldBeInLoopSimdRegion,
     } Recommend = NoRecommend;
+    if (SemaRef.LangOpts.OpenMP >= 51 && Stack->isParentOrderConcurrent() &&
+        CurrentRegion != OMPD_simd && CurrentRegion != OMPD_loop &&
+        CurrentRegion != OMPD_parallel &&
+        !isOpenMPCombinedParallelADirective(CurrentRegion)) {
+      SemaRef.Diag(StartLoc, diag::err_omp_prohibited_region_order)
+          << getOpenMPDirectiveName(CurrentRegion);
+      return true;
+    }
     if (isOpenMPSimdDirective(ParentRegion) &&
         ((SemaRef.LangOpts.OpenMP <= 45 && CurrentRegion != OMPD_ordered) ||
          (SemaRef.LangOpts.OpenMP >= 50 && CurrentRegion != OMPD_ordered &&
@@ -7195,6 +7215,13 @@
   if (!CalleeFnDecl)
     return Call;
 
+  if (LangOpts.OpenMP >= 51 && CalleeFnDecl->getIdentifier() &&
+      CalleeFnDecl->getName().startswith_insensitive("omp_")) {
+    // checking for any calls inside an Order region
+    if (Scope->isOpenMPOrderClauseScope())
+      Diag(LParenLoc, diag::err_omp_unexpected_call_to_omp_runtime_api);
+  }
+
   if (!CalleeFnDecl->hasAttr<OMPDeclareVariantAttr>())
     return Call;
 
@@ -16518,10 +16545,6 @@
         static_cast<OpenMPAtomicDefaultMemOrderClauseKind>(Argument),
         ArgumentLoc, StartLoc, LParenLoc, EndLoc);
     break;
-  case OMPC_order:
-    Res = ActOnOpenMPOrderClause(static_cast<OpenMPOrderClauseKind>(Argument),
-                                 ArgumentLoc, StartLoc, LParenLoc, EndLoc);
-    break;
   case OMPC_update:
     Res = ActOnOpenMPUpdateClause(static_cast<OpenMPDependClauseKind>(Argument),
                                   ArgumentLoc, StartLoc, LParenLoc, EndLoc);
@@ -16762,22 +16785,43 @@
   return new (Context) OMPMessageClause(ME, StartLoc, LParenLoc, EndLoc);
 }
 
-OMPClause *Sema::ActOnOpenMPOrderClause(OpenMPOrderClauseKind Kind,
-                                        SourceLocation KindKwLoc,
-                                        SourceLocation StartLoc,
-                                        SourceLocation LParenLoc,
-                                        SourceLocation EndLoc) {
-  if (Kind == OMPC_ORDER_unknown) {
+OMPClause *Sema::ActOnOpenMPOrderClause(
+    OpenMPOrderClauseModifier Modifier, OpenMPOrderClauseKind Kind,
+    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation MLoc,
+    SourceLocation KindLoc, SourceLocation EndLoc) {
+  if (Kind != OMPC_ORDER_concurrent ||
+      (LangOpts.OpenMP < 51 && MLoc.isValid())) {
+    // Kind should be concurrent,
+    // Modifiers introduced in OpenMP 5.1
     static_assert(OMPC_ORDER_unknown > 0,
                   "OMPC_ORDER_unknown not greater than 0");
-    Diag(KindKwLoc, diag::err_omp_unexpected_clause_value)
-        << getListOfPossibleValues(OMPC_order, /*First=*/0,
+
+    Diag(KindLoc, diag::err_omp_unexpected_clause_value)
+        << getListOfPossibleValues(OMPC_order,
+                                   /*First=*/0,
                                    /*Last=*/OMPC_ORDER_unknown)
         << getOpenMPClauseName(OMPC_order);
     return nullptr;
   }
-  return new (Context)
-      OMPOrderClause(Kind, KindKwLoc, StartLoc, LParenLoc, EndLoc);
+  if (LangOpts.OpenMP >= 51) {
+    if (Modifier == OMPC_ORDER_MODIFIER_unknown && MLoc.isValid()) {
+      Diag(MLoc, diag::err_omp_unexpected_clause_value)
+          << getListOfPossibleValues(OMPC_order,
+                                     /*First=*/OMPC_ORDER_MODIFIER_unknown + 1,
+                                     /*Last=*/OMPC_ORDER_MODIFIER_last)
+          << getOpenMPClauseName(OMPC_order);
+    } else {
+      DSAStack->setRegionHasOrderConcurrent(/*HasOrderConcurrent=*/true);
+      if (DSAStack->getCurScope()) {
+        // mark the current scope with 'order' flag
+        unsigned existingFlags = DSAStack->getCurScope()->getFlags();
+        DSAStack->getCurScope()->setFlags(existingFlags |
+                                          Scope::OpenMPOrderClauseScope);
+      }
+    }
+  }
+  return new (Context) OMPOrderClause(Kind, KindLoc, StartLoc, LParenLoc,
+                                      EndLoc, Modifier, MLoc);
 }
 
 OMPClause *Sema::ActOnOpenMPUpdateClause(OpenMPDependClauseKind Kind,
@@ -16889,6 +16933,13 @@
         StartLoc, LParenLoc, ArgumentLoc[Modifier], ArgumentLoc[DefaultmapKind],
         EndLoc);
     break;
+  case OMPC_order:
+    enum { OrderModifier, OrderKind };
+    Res = ActOnOpenMPOrderClause(
+        static_cast<OpenMPOrderClauseModifier>(Argument[OrderModifier]),
+        static_cast<OpenMPOrderClauseKind>(Argument[OrderKind]), StartLoc,
+        LParenLoc, ArgumentLoc[OrderModifier], ArgumentLoc[OrderKind], EndLoc);
+    break;
   case OMPC_device:
     assert(Argument.size() == 1 && ArgumentLoc.size() == 1);
     Res = ActOnOpenMPDeviceClause(
@@ -16972,7 +17023,6 @@
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_nontemporal:
-  case OMPC_order:
   case OMPC_at:
   case OMPC_severity:
   case OMPC_message:
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -2253,13 +2253,12 @@
   ///
   /// By default, performs semantic analysis to build the new OpenMP clause.
   /// Subclasses may override this routine to provide different behavior.
-  OMPClause *RebuildOMPOrderClause(OpenMPOrderClauseKind Kind,
-                                   SourceLocation KindKwLoc,
-                                   SourceLocation StartLoc,
-                                   SourceLocation LParenLoc,
-                                   SourceLocation EndLoc) {
-    return getSema().ActOnOpenMPOrderClause(Kind, KindKwLoc, StartLoc,
-                                            LParenLoc, EndLoc);
+  OMPClause *RebuildOMPOrderClause(
+      OpenMPOrderClauseKind Kind, SourceLocation KindKwLoc,
+      SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation EndLoc,
+      OpenMPOrderClauseModifier Modifier, SourceLocation ModifierKwLoc) {
+    return getSema().ActOnOpenMPOrderClause(Modifier, Kind, StartLoc, LParenLoc,
+                                            ModifierKwLoc, KindKwLoc, EndLoc);
   }
 
   /// Build a new OpenMP 'init' clause.
@@ -10611,9 +10610,9 @@
 
 template <typename Derived>
 OMPClause *TreeTransform<Derived>::TransformOMPOrderClause(OMPOrderClause *C) {
-  return getDerived().RebuildOMPOrderClause(C->getKind(), C->getKindKwLoc(),
-                                            C->getBeginLoc(), C->getLParenLoc(),
-                                            C->getEndLoc());
+  return getDerived().RebuildOMPOrderClause(
+      C->getKind(), C->getKindKwLoc(), C->getBeginLoc(), C->getLParenLoc(),
+      C->getEndLoc(), C->getModifier(), C->getModifierKwLoc());
 }
 
 template <typename Derived>
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -11251,8 +11251,10 @@
 
 void OMPClauseReader::VisitOMPOrderClause(OMPOrderClause *C) {
   C->setKind(Record.readEnum<OpenMPOrderClauseKind>());
+  C->setModifier(Record.readEnum<OpenMPOrderClauseModifier>());
   C->setLParenLoc(Record.readSourceLocation());
   C->setKindKwLoc(Record.readSourceLocation());
+  C->setModifierKwLoc(Record.readSourceLocation());
 }
 
 void OMPClauseReader::VisitOMPFilterClause(OMPFilterClause *C) {
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -7082,8 +7082,10 @@
 
 void OMPClauseWriter::VisitOMPOrderClause(OMPOrderClause *C) {
   Record.writeEnum(C->getKind());
+  Record.writeEnum(C->getModifier());
   Record.AddSourceLocation(C->getLParenLoc());
   Record.AddSourceLocation(C->getKindKwLoc());
+  Record.AddSourceLocation(C->getModifierKwLoc());
 }
 
 void OMPClauseWriter::VisitOMPUsesAllocatorsClause(OMPUsesAllocatorsClause *C) {
diff --git a/clang/test/OpenMP/distribute_parallel_for_ast_print.cpp b/clang/test/OpenMP/distribute_parallel_for_ast_print.cpp
--- a/clang/test/OpenMP/distribute_parallel_for_ast_print.cpp
+++ b/clang/test/OpenMP/distribute_parallel_for_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -std=c++11 -fopenmp -ast-print %s -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -std=c++11 -fopenmp -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
 // RUN: %clang_cc1 -verify -std=c++11 -fopenmp-simd -fopenmp-version=45 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP45
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -emit-pch -o %t %s
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -std=c++11 -fopenmp-simd -ast-print %s -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -std=c++11 -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -162,13 +168,16 @@
 #pragma omp threadprivate(g)
 #pragma omp target
 #pragma omp teams
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp distribute parallel for schedule(guided, argc) default(none) copyin(g) dist_schedule(static, a) private(a) shared(argc) order(reproducible:concurrent) reduction(task,+:c)
+#elif OMP5
 #pragma omp distribute parallel for schedule(guided, argc) default(none) copyin(g) dist_schedule(static, a) private(a) shared(argc) order(concurrent) reduction(task,+:c)
 #else
 #pragma omp distribute parallel for schedule(guided, argc) default(none) copyin(g) dist_schedule(static, a) private(a) shared(argc)
 #endif // OMP5
-  // OMP45: #pragma omp distribute parallel for schedule(guided, argc) default(none) copyin(g) dist_schedule(static, a) private(a) shared(argc)
+  // OMP51: #pragma omp distribute parallel for schedule(guided, argc) default(none) copyin(g) dist_schedule(static, a) private(a) shared(argc) order(reproducible: concurrent) reduction(task, +: c)
   // OMP50: #pragma omp distribute parallel for schedule(guided, argc) default(none) copyin(g) dist_schedule(static, a) private(a) shared(argc) order(concurrent) reduction(task, +: c)
+  // OMP45: #pragma omp distribute parallel for schedule(guided, argc) default(none) copyin(g) dist_schedule(static, a) private(a) shared(argc)
   for (int i = 0; i < 2; ++i)
     a = 2;
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
diff --git a/clang/test/OpenMP/distribute_parallel_for_messages.cpp b/clang/test/OpenMP/distribute_parallel_for_messages.cpp
--- a/clang/test/OpenMP/distribute_parallel_for_messages.cpp
+++ b/clang/test/OpenMP/distribute_parallel_for_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp -ferror-limit 100 -std=c++11 -o - %s -fopenmp-version=45 -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp -fopenmp-version=51 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp-simd -ferror-limit 100 -std=c++11 -o - %s -fopenmp-version=45 -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp-simd -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp-simd -fopenmp-version=51 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 
 void foo() {
 }
@@ -20,10 +22,10 @@
 #pragma omp distribute parallel for order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < argc; ++i)
     foo();
-#pragma omp distribute parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp distribute parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < argc; ++i)
     foo();
-#pragma omp distribute parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp distribute parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < argc; ++i)
     foo();
 #pragma omp distribute parallel for order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -32,6 +34,21 @@
 #pragma omp distribute parallel for order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}}
   for (int i = 0; i < argc; ++i)
     foo();
+#pragma omp distribute parallel for order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < argc; ++i)
+    foo();
+#pragma omp distribute parallel for order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < argc; ++i)
+    foo();
+#pragma omp distribute parallel for order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < argc; ++i)
+    foo();
+#pragma omp distribute parallel for order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < argc; ++i)
+    foo();
+#pragma omp distribute parallel for order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for'}} omp51-error {{directive '#pragma omp distribute parallel for' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < argc; ++i)
+    foo();
 #pragma omp target
 #pragma omp teams
 #pragma omp distribute parallel for { // expected-warning {{extra tokens at the end of '#pragma omp distribute parallel for' are ignored}}
diff --git a/clang/test/OpenMP/distribute_parallel_for_simd_ast_print.cpp b/clang/test/OpenMP/distribute_parallel_for_simd_ast_print.cpp
--- a/clang/test/OpenMP/distribute_parallel_for_simd_ast_print.cpp
+++ b/clang/test/OpenMP/distribute_parallel_for_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -ast-print %s -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=45 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP45
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -emit-pch -o %t %s
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -149,16 +155,19 @@
   int i;
 #pragma omp target
 #pragma omp teams
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp distribute parallel for simd aligned(x:8) linear(i:2) safelen(8) simdlen(8) if(simd: argc) nontemporal(argc, c, d) order(unconstrained:concurrent)
+#elif OMP5
 #pragma omp distribute parallel for simd aligned(x:8) linear(i:2) safelen(8) simdlen(8) if(simd: argc) nontemporal(argc, c, d) order(concurrent)
 #else
 #pragma omp distribute parallel for simd aligned(x:8) linear(i:2) safelen(8) simdlen(8)
-#endif // OMP5
+#endif // OMP51
   for (i = 0; i < 100; i++)
     for (int j = 0; j < 200; j++)
       a += h + x[j];
   // OMP45: #pragma omp distribute parallel for simd aligned(x: 8) linear(i: 2) safelen(8) simdlen(8)
   // OMP50: #pragma omp distribute parallel for simd aligned(x: 8) linear(i: 2) safelen(8) simdlen(8) if(simd: argc) nontemporal(argc,c,d) order(concurrent)
+  // OMP51: #pragma omp distribute parallel for simd aligned(x: 8) linear(i: 2) safelen(8) simdlen(8) if(simd: argc) nontemporal(argc,c,d) order(unconstrained: concurrent)
   // CHECK-NEXT: for (i = 0; i < 100; i++)
   // CHECK-NEXT: for (int j = 0; j < 200; j++)
   // CHECK-NEXT: a += h + x[j];
diff --git a/clang/test/OpenMP/distribute_parallel_for_simd_misc_messages.c b/clang/test/OpenMP/distribute_parallel_for_simd_misc_messages.c
--- a/clang/test/OpenMP/distribute_parallel_for_simd_misc_messages.c
+++ b/clang/test/OpenMP/distribute_parallel_for_simd_misc_messages.c
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -922,7 +924,7 @@
 #pragma omp distribute parallel for simd nontemporal(int)
   for (i = 0; i < 16; ++i)
     ;
-// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp distribute parallel for simd'}} omp50-error@+1 {{expected variable name}}
+// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp distribute parallel for simd'}} omp50-error@+1 {{expected variable name}} omp51-error@+1 {{expected variable name}}
 #pragma omp distribute parallel for simd nontemporal(0)
   for (i = 0; i < 16; ++i)
     ;
@@ -952,8 +954,9 @@
   for (i = 0; i < 16; ++i)
     ;
 
+// omp51-note@+3 {{defined as nontemporal}}
 // omp50-note@+2 {{defined as nontemporal}}
-// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp distribute parallel for simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
+// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp distribute parallel for simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}} omp51-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
 #pragma omp distribute parallel for simd nontemporal(x) nontemporal(x)
   for (i = 0; i < 16; ++i)
     ;
@@ -985,10 +988,10 @@
 #pragma omp distribute parallel for simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp distribute parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp distribute parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp distribute parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp distribute parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp distribute parallel for simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -997,5 +1000,20 @@
 #pragma omp distribute parallel for simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp distribute parallel for simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp distribute parallel for simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp distribute parallel for simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp distribute parallel for simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp distribute parallel for simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute parallel for simd'}} omp51-error {{directive '#pragma omp distribute parallel for simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/distribute_simd_ast_print.cpp b/clang/test/OpenMP/distribute_simd_ast_print.cpp
--- a/clang/test/OpenMP/distribute_simd_ast_print.cpp
+++ b/clang/test/OpenMP/distribute_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -ast-print %s -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=45 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP45
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -emit-pch -o %t %s
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -140,6 +146,7 @@
             a++;
 // OMP45: #pragma omp distribute simd private(argc,b) firstprivate(argv,c) lastprivate(d,f) collapse(2) reduction(+: h) dist_schedule(static, b)
 // OMP50: #pragma omp distribute simd private(argc,b) firstprivate(argv,c) lastprivate(d,f) collapse(2) reduction(+: h) dist_schedule(static, b) if(simd: argc)
+// OMP51: #pragma omp distribute simd private(argc,b) firstprivate(argv,c) lastprivate(d,f) collapse(2) reduction(+: h) dist_schedule(static, b)
 // CHECK-NEXT: for (int i = 0; i < 10; ++i)
 // CHECK-NEXT: for (int j = 0; j < 10; ++j)
 // CHECK-NEXT: a++;
@@ -147,16 +154,19 @@
   int i;
 #pragma omp target
 #pragma omp teams
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp distribute simd aligned(x:8) linear(i:2) safelen(8) simdlen(8) if(argc) nontemporal(argc, c, d) order(reproducible:concurrent)
+#elif OMP5
 #pragma omp distribute simd aligned(x:8) linear(i:2) safelen(8) simdlen(8) if(argc) nontemporal(argc, c, d) order(concurrent)
 #else
 #pragma omp distribute simd aligned(x:8) linear(i:2) safelen(8) simdlen(8)
-#endif // OMP5
+#endif // OMP51
   for (i = 0; i < 100; i++)
     for (int j = 0; j < 200; j++)
       a += h + x[j];
 // OMP45: #pragma omp distribute simd aligned(x: 8) linear(i: 2) safelen(8) simdlen(8)
 // OMP50: #pragma omp distribute simd aligned(x: 8) linear(i: 2) safelen(8) simdlen(8) if(argc) nontemporal(argc,c,d) order(concurrent)
+// OMP51: #pragma omp distribute simd aligned(x: 8) linear(i: 2) safelen(8) simdlen(8) if(argc) nontemporal(argc,c,d) order(reproducible: concurrent)
 // CHECK-NEXT: for (i = 0; i < 100; i++)
 // CHECK-NEXT: for (int j = 0; j < 200; j++)
 // CHECK-NEXT: a += h + x[j];
diff --git a/clang/test/OpenMP/distribute_simd_misc_messages.c b/clang/test/OpenMP/distribute_simd_misc_messages.c
--- a/clang/test/OpenMP/distribute_simd_misc_messages.c
+++ b/clang/test/OpenMP/distribute_simd_misc_messages.c
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -1056,7 +1058,7 @@
 #pragma omp distribute simd nontemporal(int)
   for (i = 0; i < 16; ++i)
     ;
-// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp distribute simd'}} omp50-error@+1 {{expected variable name}}
+// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp distribute simd'}} omp50-error@+1 {{expected variable name}} omp51-error@+1 {{expected variable name}}
 #pragma omp distribute simd nontemporal(0)
   for (i = 0; i < 16; ++i)
     ;
@@ -1086,8 +1088,9 @@
   for (i = 0; i < 16; ++i)
     ;
 
+// omp51-note@+3 {{defined as nontemporal}}
 // omp50-note@+2 {{defined as nontemporal}}
-// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp distribute simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
+// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp distribute simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}} omp51-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
 #pragma omp distribute simd nontemporal(x) nontemporal(x)
   for (i = 0; i < 16; ++i)
     ;
@@ -1119,10 +1122,10 @@
 #pragma omp distribute simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp distribute simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp distribute simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp distribute simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp distribute simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp distribute simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -1131,5 +1134,20 @@
 #pragma omp distribute simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp distribute simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp distribute simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp distribute simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp distribute simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp distribute simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp distribute simd'}} omp51-error {{directive '#pragma omp distribute simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/for_ast_print.cpp b/clang/test/OpenMP/for_ast_print.cpp
--- a/clang/test/OpenMP/for_ast_print.cpp
+++ b/clang/test/OpenMP/for_ast_print.cpp
@@ -1,10 +1,16 @@
-// RUN: %clang_cc1 -verify -fopenmp -ast-print %s -Wsign-conversion | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -ast-print %s -Wsign-conversion | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -Wsign-conversion -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
-// RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s -Wsign-conversion | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s -Wsign-conversion | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
+// RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wsign-conversion -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -221,8 +227,13 @@
   float arr[20];
   static int a;
 // CHECK: static int a;
+#ifdef OMP51
+#pragma omp for schedule(guided, argc) reduction(+:argv[0][:1]) order(unconstrained:concurrent)
+#else
 #pragma omp for schedule(guided, argc) reduction(+:argv[0][:1]) order(concurrent)
-  // CHECK-NEXT: #pragma omp for schedule(guided, argc) reduction(+: argv[0][:1]) order(concurrent)
+#endif // OMP51
+  // OMP50: #pragma omp for schedule(guided, argc) reduction(+: argv[0][:1]) order(concurrent)
+  // OMP51: #pragma omp for schedule(guided, argc) reduction(+: argv[0][:1]) order(unconstrained: concurrent)
   for (int i = argc; i < c; ++i)
     a = 2;
 // CHECK-NEXT: for (int i = argc; i < c; ++i)
diff --git a/clang/test/OpenMP/for_misc_messages.c b/clang/test/OpenMP/for_misc_messages.c
--- a/clang/test/OpenMP/for_misc_messages.c
+++ b/clang/test/OpenMP/for_misc_messages.c
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -triple x86_64-unknown-unknown -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -triple x86_64-unknown-unknown -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -triple x86_64-unknown-unknown -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -triple x86_64-unknown-unknown -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -402,16 +404,34 @@
 #pragma omp for order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp for order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp for ordered order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} omp50-error {{'order' clause with 'concurrent' modifier cannot be specified if an 'ordered' clause is specified}} omp50-note {{'ordered' clause}}
+#pragma omp for order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for ordered order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} omp50-error {{'order' clause with 'concurrent' modifier cannot be specified if an 'ordered' clause is specified}} omp50-note {{'ordered' clause}} omp51-error {{'order' clause with 'concurrent' modifier cannot be specified if an 'ordered' clause is specified}} omp51-note {{'ordered' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for'}} omp51-error {{directive '#pragma omp for' cannot contain more than one 'order' clause}}
   for (int i = 0; i < 10; ++i)
     ;
 }
diff --git a/clang/test/OpenMP/for_order_messages.cpp b/clang/test/OpenMP/for_order_messages.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/OpenMP/for_order_messages.cpp
@@ -0,0 +1,47 @@
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -triple x86_64-unknown-unknown -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
+
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -triple x86_64-unknown-unknown -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
+
+extern int omp_get_num_threads  (void);
+
+int main(int argc, char **argv) {
+  int A = 0;
+#pragma omp parallel for order(concurrent)
+  for (int i = 0; i < 10; ++i)
+    omp_get_num_threads(); // omp51-error {{calls to OpenMP runtime API are not allowed within a region that corresponds to a construct with an order clause that specifies concurrent}}
+
+#pragma omp parallel for order(reproducible:concurrent) // omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    omp_get_num_threads(); // omp51-error {{calls to OpenMP runtime API are not allowed within a region that corresponds to a construct with an order clause that specifies concurrent}}
+
+#pragma omp parallel for order(unconstrained:concurrent) // omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    omp_get_num_threads(); // omp51-error {{calls to OpenMP runtime API are not allowed within a region that corresponds to a construct with an order clause that specifies concurrent}}
+
+#pragma omp parallel for order(concurrent)
+  for (int i = 0; i < 10; ++i) {
+    for (int j = 0; j < 10; ++j) {
+      omp_get_num_threads(); // omp51-error {{calls to OpenMP runtime API are not allowed within a region that corresponds to a construct with an order clause that specifies concurrent}}
+    }
+  }
+
+#pragma omp parallel for order(concurrent)
+  for (int i = 0; i < 10; ++i) {
+#pragma omp atomic //omp51-error {{construct 'atomic' not allowed in a region associated with a directive with 'order' clause}}
+      A++;
+  }
+
+#pragma omp parallel for order(reproducible: concurrent) // omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i) {
+#pragma omp target //omp51-error {{construct 'target' not allowed in a region associated with a directive with 'order' clause}}
+      A++;
+  }
+
+#pragma omp parallel for order(unconstrained: concurrent) // omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i) {
+#pragma omp target //omp51-error {{construct 'target' not allowed in a region associated with a directive with 'order' clause}}
+      A++;
+  }
+}
diff --git a/clang/test/OpenMP/for_simd_ast_print.cpp b/clang/test/OpenMP/for_simd_ast_print.cpp
--- a/clang/test/OpenMP/for_simd_ast_print.cpp
+++ b/clang/test/OpenMP/for_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -ast-print %s -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=45 -ast-print %s | FileCheck %s --check-prefix=CHECK --check-prefix=OMP45
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -emit-pch -o %t %s
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -96,11 +102,14 @@
 // CHECK: T res;
 // CHECK: T val;
 // CHECK: T lin = 0;
-#ifdef OMP5
+#ifdef OMP51
+    #pragma omp for simd private(val)  safelen(7) linear(lin : -5) lastprivate(res) simdlen(5) allocate(res) if(res) nontemporal(res, val, lin) order(reproducible:concurrent)
+#elif OMP5
     #pragma omp for simd private(val)  safelen(7) linear(lin : -5) lastprivate(res) simdlen(5) allocate(res) if(res) nontemporal(res, val, lin) order(concurrent)
 #else
     #pragma omp for simd private(val)  safelen(7) linear(lin : -5) lastprivate(res) simdlen(5) allocate(res)
-#endif
+#endif // OMP51
+// OMP51-NEXT: #pragma omp for simd private(val) safelen(7) linear(lin: -5) lastprivate(res) simdlen(5) allocate(res) if(res) nontemporal(res,val,lin) order(reproducible: concurrent)
 // OMP50-NEXT: #pragma omp for simd private(val) safelen(7) linear(lin: -5) lastprivate(res) simdlen(5) allocate(res) if(res) nontemporal(res,val,lin) order(concurrent)
 // OMP45-NEXT: #pragma omp for simd private(val) safelen(7) linear(lin: -5) lastprivate(res) simdlen(5) allocate(res)
     for (T i = 7; i < m_a; ++i) {
@@ -185,6 +194,7 @@
 #else
   #pragma omp for simd aligned(a:CLEN) linear(a:CLEN) safelen(CLEN) collapse( 1 ) simdlen(CLEN)
 #endif
+// OMP51-NEXT: #pragma omp for simd aligned(a: CLEN) linear(a: CLEN) safelen(CLEN) collapse(1) simdlen(CLEN)
 // OMP50-NEXT: #pragma omp for simd aligned(a: CLEN) linear(a: CLEN) safelen(CLEN) collapse(1) simdlen(CLEN) if(simd: a)
 // OMP45-NEXT: #pragma omp for simd aligned(a: CLEN) linear(a: CLEN) safelen(CLEN) collapse(1) simdlen(CLEN)
   for (int i = 0; i < 10; ++i)foo();
diff --git a/clang/test/OpenMP/for_simd_misc_messages.c b/clang/test/OpenMP/for_simd_misc_messages.c
--- a/clang/test/OpenMP/for_simd_misc_messages.c
+++ b/clang/test/OpenMP/for_simd_misc_messages.c
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -verify=expected,omp45 -verify %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -verify=expected,omp50 -verify %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -verify=expected,omp51 -verify %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -787,7 +789,7 @@
 #pragma omp for simd nontemporal(int)
   for (i = 0; i < 16; ++i)
     ;
-// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp for simd'}} omp50-error@+1 {{expected variable name}}
+// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp for simd'}} omp50-error@+1 {{expected variable name}} omp51-error@+1 {{expected variable name}}
 #pragma omp for simd nontemporal(0)
   for (i = 0; i < 16; ++i)
     ;
@@ -817,8 +819,9 @@
   for (i = 0; i < 16; ++i)
     ;
 
+// omp51-note@+3 {{defined as nontemporal}}
 // omp50-note@+2 {{defined as nontemporal}}
-// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp for simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
+// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp for simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}} omp51-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
 #pragma omp for simd nontemporal(x) nontemporal(x)
   for (i = 0; i < 16; ++i)
     ;
@@ -852,10 +855,10 @@
 #pragma omp for simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp for simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -864,5 +867,20 @@
 #pragma omp for simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp for simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp for simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp for simd'}} omp51-error {{directive '#pragma omp for simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/master_taskloop_simd_ast_print.cpp b/clang/test/OpenMP/master_taskloop_simd_ast_print.cpp
--- a/clang/test/OpenMP/master_taskloop_simd_ast_print.cpp
+++ b/clang/test/OpenMP/master_taskloop_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -ast-print %s -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -DOMP51 | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP51 | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -DOMP5 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -DOMP51 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -75,16 +81,19 @@
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
 // CHECK-NEXT: a = 2;
 #pragma omp parallel
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp master taskloop simd private(argc, b), firstprivate(argv, c), lastprivate(d, f) collapse(2) shared(g) if(simd:argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a, e) nontemporal(argc, c, d) order(unconstrained:concurrent)
+#elif OMP5
 #pragma omp master taskloop simd private(argc, b), firstprivate(argv, c), lastprivate(d, f) collapse(2) shared(g) if(simd:argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a, e) nontemporal(argc, c, d) order(concurrent)
 #else
 #pragma omp master taskloop simd private(argc, b), firstprivate(argv, c), lastprivate(d, f) collapse(2) shared(g) if(argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a, e)
-#endif // OMP5
+#endif // OMP51
   for (int i = 0; i < 10; ++i)
     for (int j = 0; j < 10; ++j)
       foo();
   // CHECK-NEXT: #pragma omp parallel
   // OMP50-NEXT: #pragma omp master taskloop simd private(argc,b) firstprivate(argv,c) lastprivate(d,f) collapse(2) shared(g) if(simd: argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a,e) nontemporal(argc,c,d) order(concurrent)
+  // OMP51-NEXT: #pragma omp master taskloop simd private(argc,b) firstprivate(argv,c) lastprivate(d,f) collapse(2) shared(g) if(simd: argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a,e) nontemporal(argc,c,d) order(unconstrained: concurrent)
   // CHECK-NEXT: for (int i = 0; i < 10; ++i)
   // CHECK-NEXT: for (int j = 0; j < 10; ++j)
   // CHECK-NEXT: foo();
diff --git a/clang/test/OpenMP/parallel_for_ast_print.cpp b/clang/test/OpenMP/parallel_for_ast_print.cpp
--- a/clang/test/OpenMP/parallel_for_ast_print.cpp
+++ b/clang/test/OpenMP/parallel_for_ast_print.cpp
@@ -1,10 +1,16 @@
-// RUN: %clang_cc1 -verify -fopenmp -ast-print %s | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -ast-print %s | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
-// RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
+// RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -70,8 +76,13 @@
 // CHECK: static T a;
   static T g;
 #pragma omp threadprivate(g)
+#ifdef OMP51
+#pragma omp parallel for schedule(dynamic) default(none) copyin(g) linear(a) allocate(a) lastprivate(conditional: d, e,f) order(reproducible:concurrent)
+#else
 #pragma omp parallel for schedule(dynamic) default(none) copyin(g) linear(a) allocate(a) lastprivate(conditional: d, e,f) order(concurrent)
-  // CHECK: #pragma omp parallel for schedule(dynamic) default(none) copyin(g) linear(a) allocate(a) lastprivate(conditional: d,e,f) order(concurrent)
+#endif // OMP51
+  // OMP50: #pragma omp parallel for schedule(dynamic) default(none) copyin(g) linear(a) allocate(a) lastprivate(conditional: d,e,f) order(concurrent)
+  // OMP51: #pragma omp parallel for schedule(dynamic) default(none) copyin(g) linear(a) allocate(a) lastprivate(conditional: d,e,f) order(reproducible: concurrent)
   for (int i = 0; i < 2; ++i)
     a = 2;
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
diff --git a/clang/test/OpenMP/parallel_for_messages.cpp b/clang/test/OpenMP/parallel_for_messages.cpp
--- a/clang/test/OpenMP/parallel_for_messages.cpp
+++ b/clang/test/OpenMP/parallel_for_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp -fopenmp-version=45 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp -fopenmp-version=51 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp-simd -fopenmp-version=45 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp-simd -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp-simd -fopenmp-version=51 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -96,10 +98,10 @@
 #pragma omp parallel for order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp parallel for order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -108,5 +110,20 @@
 #pragma omp parallel for order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp parallel for order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp parallel for order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp parallel for order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp parallel for order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp parallel for order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for'}} omp51-error {{directive '#pragma omp parallel for' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/parallel_for_simd_ast_print.cpp b/clang/test/OpenMP/parallel_for_simd_ast_print.cpp
--- a/clang/test/OpenMP/parallel_for_simd_ast_print.cpp
+++ b/clang/test/OpenMP/parallel_for_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -DOMP5 -ast-print %s | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -DOMP51 -ast-print %s | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=45 -ast-print %s | FileCheck %s --check-prefix=CHECK --check-prefix=OMP45
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -emit-pch -o %t %s
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -DOMP5 -ast-print %s | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp-simd -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -DOMP51 -ast-print %s | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -154,11 +160,14 @@
   int k1=0,k2=0;
   static int *a;
 // CHECK: static int *a;
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp parallel for simd if(parallel :b) if(simd: b) nontemporal(argc, c) lastprivate(conditional:d,f) order(unconstrained:concurrent)
+#elif OMP5
 #pragma omp parallel for simd if(parallel :b) if(simd: b) nontemporal(argc, c) lastprivate(conditional:d,f) order(concurrent)
 #else
 #pragma omp parallel for simd if(parallel :b) ordered
-#endif // OMP5
+#endif // OMP51
+// OMP51-NEXT: #pragma omp parallel for simd if(parallel: b) if(simd: b) nontemporal(argc,c) lastprivate(conditional: d,f) order(unconstrained: concurrent)
 // OMP50-NEXT: #pragma omp parallel for simd if(parallel: b) if(simd: b) nontemporal(argc,c) lastprivate(conditional: d,f) order(concurrent)
 // OMP45-NEXT: #pragma omp parallel for simd if(parallel: b) ordered
   for (int i=0; i < 2; ++i)*a=2;
diff --git a/clang/test/OpenMP/parallel_for_simd_misc_messages.c b/clang/test/OpenMP/parallel_for_simd_misc_messages.c
--- a/clang/test/OpenMP/parallel_for_simd_misc_messages.c
+++ b/clang/test/OpenMP/parallel_for_simd_misc_messages.c
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 // expected-error@+1 {{unexpected OpenMP directive '#pragma omp parallel for simd'}}
 #pragma omp parallel for simd
@@ -778,7 +780,7 @@
 #pragma omp parallel for simd nontemporal(int)
   for (i = 0; i < 16; ++i)
     ;
-// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp parallel for simd'}} omp50-error@+1 {{expected variable name}}
+// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp parallel for simd'}} omp50-error@+1 {{expected variable name}} omp51-error@+1 {{expected variable name}}
 #pragma omp parallel for simd nontemporal(0)
   for (i = 0; i < 16; ++i)
     ;
@@ -808,8 +810,9 @@
   for (i = 0; i < 16; ++i)
     ;
 
+// omp51-note@+3 {{defined as nontemporal}}
 // omp50-note@+2 {{defined as nontemporal}}
-// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp parallel for simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
+// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp parallel for simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}} omp51-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
 #pragma omp parallel for simd nontemporal(x) nontemporal(x)
   for (i = 0; i < 16; ++i)
     ;
@@ -841,10 +844,10 @@
 #pragma omp parallel for simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp parallel for simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -853,5 +856,20 @@
 #pragma omp parallel for simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp parallel for simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp parallel for simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp parallel for simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp parallel for simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp parallel for simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp parallel for simd'}} omp51-error {{directive '#pragma omp parallel for simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/parallel_master_taskloop_simd_ast_print.cpp b/clang/test/OpenMP/parallel_master_taskloop_simd_ast_print.cpp
--- a/clang/test/OpenMP/parallel_master_taskloop_simd_ast_print.cpp
+++ b/clang/test/OpenMP/parallel_master_taskloop_simd_ast_print.cpp
@@ -1,16 +1,16 @@
 // RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -DOMP5 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix CHECK --check-prefix OMP50
-// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
-// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
-// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -DOMP51 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -DOMP5 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix CHECK --check-prefix OMP50
-// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
-// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
-// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -DOMP51 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -74,16 +74,19 @@
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
 // CHECK-NEXT: a = 2;
 #pragma omp parallel
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp parallel master taskloop simd private(argc, b), firstprivate(argv, c), lastprivate(d, f) collapse(2) shared(g) if(simd:argc) mergeable priority(argc) grainsize(argc) reduction(max: a, e) nontemporal(argc, c, d) order(reproducible:concurrent)
+#elif OMP5
 #pragma omp parallel master taskloop simd private(argc, b), firstprivate(argv, c), lastprivate(d, f) collapse(2) shared(g) if(simd:argc) mergeable priority(argc) grainsize(argc) reduction(max: a, e) nontemporal(argc, c, d) order(concurrent)
 #else
 #pragma omp parallel master taskloop simd private(argc, b), firstprivate(argv, c), lastprivate(d, f) collapse(2) shared(g) if(argc) mergeable priority(argc) grainsize(argc) reduction(max: a, e)
-#endif // OMP5
+#endif // OMP51
   for (int i = 0; i < 10; ++i)
     for (int j = 0; j < 10; ++j)
       foo();
   // CHECK-NEXT: #pragma omp parallel
   // OMP50-NEXT: #pragma omp parallel master taskloop simd private(argc,b) firstprivate(argv,c) lastprivate(d,f) collapse(2) shared(g) if(simd: argc) mergeable priority(argc) grainsize(argc) reduction(max: a,e) nontemporal(argc,c,d) order(concurrent)
+  // OMP51-NEXT: #pragma omp parallel master taskloop simd private(argc,b) firstprivate(argv,c) lastprivate(d,f) collapse(2) shared(g) if(simd: argc) mergeable priority(argc) grainsize(argc) reduction(max: a,e) nontemporal(argc,c,d) order(reproducible: concurrent)
   // CHECK-NEXT: for (int i = 0; i < 10; ++i)
   // CHECK-NEXT: for (int j = 0; j < 10; ++j)
   // CHECK-NEXT: foo();
diff --git a/clang/test/OpenMP/simd_ast_print.cpp b/clang/test/OpenMP/simd_ast_print.cpp
--- a/clang/test/OpenMP/simd_ast_print.cpp
+++ b/clang/test/OpenMP/simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s | FileCheck %s --check-prefix=CHECK --check-prefix=OMP45
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -163,13 +169,16 @@
   for (int i=0; i < 2; ++i)*a=2;
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
 // CHECK-NEXT: *a = 2;
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp simd private(argc, b),lastprivate(d,f) collapse(2) aligned(a : 4) if(simd:a) nontemporal(argc, c, d) lastprivate(conditional: e, f) order(unconstrained:concurrent)
+// OMP51-NEXT: #pragma omp simd private(argc,b) lastprivate(d,f) collapse(2) aligned(a: 4) if(simd: a) nontemporal(argc,c,d) lastprivate(conditional: e,f) order(unconstrained: concurrent)
+#elif OMP5
 #pragma omp simd private(argc, b),lastprivate(d,f) collapse(2) aligned(a : 4) if(simd:a) nontemporal(argc, c, d) lastprivate(conditional: e, f) order(concurrent)
 // OMP50-NEXT: #pragma omp simd private(argc,b) lastprivate(d,f) collapse(2) aligned(a: 4) if(simd: a) nontemporal(argc,c,d) lastprivate(conditional: e,f) order(concurrent)
 #else
 #pragma omp simd private(argc, b),lastprivate(d,f) collapse(2) aligned(a : 4)
 // OMP45-NEXT: #pragma omp simd private(argc,b) lastprivate(d,f) collapse(2) aligned(a: 4)
-#endif // OMP5
+#endif // OMP51
   for (int i = 0; i < 10; ++i)
   for (int j = 0; j < 10; ++j) {foo(); k1 += 8; k2 += 8;}
 // CHECK-NEXT: for (int i = 0; i < 10; ++i)
@@ -189,6 +198,7 @@
 #else
   #pragma omp simd aligned(a:CLEN) linear(a:CLEN) safelen(CLEN) collapse( 1 ) simdlen(CLEN) linear(val(ref): CLEN)
 // OMP45-NEXT: #pragma omp simd aligned(a: CLEN) linear(a: CLEN) safelen(CLEN) collapse(1) simdlen(CLEN) linear(val(ref): CLEN)
+// OMP51-NEXT: #pragma omp simd aligned(a: CLEN) linear(a: CLEN) safelen(CLEN) collapse(1) simdlen(CLEN) linear(val(ref): CLEN)
 #endif // OMP5
   for (int i = 0; i < 10; ++i)foo();
 // CHECK-NEXT: for (int i = 0; i < 10; ++i)
diff --git a/clang/test/OpenMP/simd_misc_messages.c b/clang/test/OpenMP/simd_misc_messages.c
--- a/clang/test/OpenMP/simd_misc_messages.c
+++ b/clang/test/OpenMP/simd_misc_messages.c
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=50 -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=50 -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -828,7 +830,7 @@
 #pragma omp simd nontemporal(int)
   for (i = 0; i < 16; ++i)
     ;
-// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp simd'}} omp50-error@+1 {{expected variable name}}
+// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp simd'}} omp50-error@+1 {{expected variable name}} omp51-error@+1 {{expected variable name}}
 #pragma omp simd nontemporal(0)
   for (i = 0; i < 16; ++i)
     ;
@@ -858,8 +860,9 @@
   for (i = 0; i < 16; ++i)
     ;
 
+// omp51-note@+3 {{defined as nontemporal}}
 // omp50-note@+2 {{defined as nontemporal}}
-// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
+// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}} omp51-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
 #pragma omp simd nontemporal(x) nontemporal(x)
   for (i = 0; i < 16; ++i)
     ;
@@ -891,10 +894,10 @@
 #pragma omp simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -903,5 +906,20 @@
 #pragma omp simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp simd'}} omp51-error {{directive '#pragma omp simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/target_parallel_for_ast_print.cpp b/clang/test/OpenMP/target_parallel_for_ast_print.cpp
--- a/clang/test/OpenMP/target_parallel_for_ast_print.cpp
+++ b/clang/test/OpenMP/target_parallel_for_ast_print.cpp
@@ -1,10 +1,16 @@
-// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
-// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
-// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
-// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -84,8 +90,13 @@
 // CHECK: static T a;
   static T g;
 #pragma omp threadprivate(g)
+#ifdef OMP51
+#pragma omp target parallel for schedule(dynamic) default(none) linear(a) allocate(a) order(reproducible:concurrent)
+#else
 #pragma omp target parallel for schedule(dynamic) default(none) linear(a) allocate(a) order(concurrent)
-  // CHECK: #pragma omp target parallel for schedule(dynamic) default(none) linear(a) allocate(a) order(concurrent)
+#endif // OMP51
+  // OMP51: #pragma omp target parallel for schedule(dynamic) default(none) linear(a) allocate(a) order(reproducible: concurrent)
+  // OMP50: #pragma omp target parallel for schedule(dynamic) default(none) linear(a) allocate(a) order(concurrent)
   for (int i = 0; i < 2; ++i)
     a = 2;
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
diff --git a/clang/test/OpenMP/target_parallel_for_messages.cpp b/clang/test/OpenMP/target_parallel_for_messages.cpp
--- a/clang/test/OpenMP/target_parallel_for_messages.cpp
+++ b/clang/test/OpenMP/target_parallel_for_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp -fopenmp-version=45 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp -fopenmp-version=50 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp -fopenmp-version=51 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp-simd -fopenmp-version=45 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp-simd -fopenmp-version=50 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp-simd -fopenmp-version=51 -ferror-limit 100 -std=c++11 -o - %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -102,10 +104,10 @@
 #pragma omp target parallel for order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target parallel for order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -114,5 +116,20 @@
 #pragma omp target parallel for order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp target parallel for order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target parallel for order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target parallel for order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target parallel for order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target parallel for order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for'}} omp51-error {{directive '#pragma omp target parallel for' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/target_parallel_for_simd_ast_print.cpp b/clang/test/OpenMP/target_parallel_for_simd_ast_print.cpp
--- a/clang/test/OpenMP/target_parallel_for_simd_ast_print.cpp
+++ b/clang/test/OpenMP/target_parallel_for_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP5
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=45 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP45
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP5
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP5 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -125,14 +131,17 @@
   // CHECK-NEXT: for (T i = 0; i < 2; ++i) {
   // CHECK-NEXT: }
 
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp target parallel for simd if(target:argc > 0) if (simd: argc) nontemporal(argc, c, d) order(unconstrained:concurrent) allocate(omp_high_bw_mem_alloc:f) private(f) uses_allocators(omp_high_bw_mem_alloc)
+#elif OMP5
 #pragma omp target parallel for simd if(target:argc > 0) if (simd: argc) nontemporal(argc, c, d) order(concurrent) allocate(omp_high_bw_mem_alloc:f) private(f) uses_allocators(omp_high_bw_mem_alloc)
 #else
 #pragma omp target parallel for simd if(target:argc > 0)
-#endif // OMP5
+#endif // OMP51
   for (T i = 0; i < 2; ++i) {}
   // OMP45: #pragma omp target parallel for simd if(target: argc > 0)
   // OMP50: #pragma omp target parallel for simd if(target: argc > 0) if(simd: argc) nontemporal(argc,c,d) order(concurrent) allocate(omp_high_bw_mem_alloc: f) private(f) uses_allocators(omp_high_bw_mem_alloc)
+  // OMP51: #pragma omp target parallel for simd if(target: argc > 0) if(simd: argc) nontemporal(argc,c,d) order(unconstrained: concurrent) allocate(omp_high_bw_mem_alloc: f) private(f) uses_allocators(omp_high_bw_mem_alloc)
   // CHECK-NEXT: for (T i = 0; i < 2; ++i) {
   // CHECK-NEXT: }
 
@@ -256,14 +265,17 @@
   // CHECK-NEXT: for (int i = 0; i < 2; ++i) {
   // CHECK-NEXT: }
 
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp target parallel for simd if (parallel:argc > 0)
+#elif OMP5
 #pragma omp target parallel for simd if (parallel:argc > 0) if(simd: argc)
 #else
 #pragma omp target parallel for simd if (parallel:argc > 0)
-#endif // OMP5
+#endif // OMP51
   for (int i = 0; i < 2; ++i) {}
   // OMP45: #pragma omp target parallel for simd if(parallel: argc > 0)
   // OMP50: #pragma omp target parallel for simd if(parallel: argc > 0) if(simd: argc)
+  // OMP51: #pragma omp target parallel for simd if(parallel: argc > 0)
   // CHECK-NEXT: for (int i = 0; i < 2; ++i) {
   // CHECK-NEXT: }
 
diff --git a/clang/test/OpenMP/target_parallel_for_simd_loop_messages.cpp b/clang/test/OpenMP/target_parallel_for_simd_loop_messages.cpp
--- a/clang/test/OpenMP/target_parallel_for_simd_loop_messages.cpp
+++ b/clang/test/OpenMP/target_parallel_for_simd_loop_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp45 %s -Wno-openmp-mapping -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp50 %s -Wno-openmp-mapping -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp51 %s -Wno-openmp-mapping -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp45 %s -Wno-openmp-mapping -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp50 %s -Wno-openmp-mapping -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp51 %s -Wno-openmp-mapping -Wuninitialized
 
 class S {
   int a;
@@ -94,28 +96,28 @@
   for (((ii)) = 0; ii < 10; ++ii)
     c[ii] = a[ii];
 
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
 #pragma omp target parallel for simd
   for (int i = 0; i; i++)
     c[i] = a[i];
 
-// omp45-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
 // expected-error@+2 {{increment clause of OpenMP for loop must perform simple addition or subtraction on loop variable 'i'}}
 #pragma omp target parallel for simd
   for (int i = 0; jj < kk; ii++)
     c[i] = a[i];
 
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
 #pragma omp target parallel for simd
   for (int i = 0; !!i; i++)
     c[i] = a[i];
 
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}}	
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}}
 #pragma omp target parallel for simd
   for (int i = 0; i != 1; i++)
     c[i] = a[i];
 
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
 #pragma omp target parallel for simd
   for (int i = 0;; i++)
     c[i] = a[i];
@@ -420,15 +422,15 @@
 #pragma omp target parallel for simd
   for (begin = end; begin < end; ++begin)
     ++begin;
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
 #pragma omp target parallel for simd
   for (GoodIter I = begin; I - I; ++I)
     ++I;
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
 #pragma omp target parallel for simd
   for (GoodIter I = begin; begin < end; ++I)
     ++I;
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
 #pragma omp target parallel for simd
   for (GoodIter I = begin; !I; ++I)
     ++I;
@@ -633,10 +635,10 @@
 #pragma omp target parallel for simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target parallel for simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -645,4 +647,19 @@
 #pragma omp target parallel for simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp target parallel for simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target parallel for simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target parallel for simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target parallel for simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target parallel for simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target parallel for simd'}} omp51-error {{directive '#pragma omp target parallel for simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
diff --git a/clang/test/OpenMP/target_simd_ast_print.cpp b/clang/test/OpenMP/target_simd_ast_print.cpp
--- a/clang/test/OpenMP/target_simd_ast_print.cpp
+++ b/clang/test/OpenMP/target_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -DOMP5 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=45 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP45
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -DOMP5 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -134,6 +140,7 @@
   for (T i = 0; i < 2; ++i) {}
   // OMP45: #pragma omp target simd if(target: argc > 0)
   // OMP50: #pragma omp target simd if(target: argc > 0) if(simd: argc) allocate(omp_default_mem_alloc: f) private(f) uses_allocators(omp_default_mem_alloc)
+  // OMP51: #pragma omp target simd if(target: argc > 0)
   // CHECK-NEXT: for (T i = 0; i < 2; ++i) {
   // CHECK-NEXT: }
 
@@ -252,14 +259,17 @@
   // CHECK-NEXT: for (int i = 0; i < 2; ++i) {
   // CHECK-NEXT: }
 
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp target simd if (target:argc > 0) if(simd:argc) nontemporal(argc, c, d) lastprivate(conditional: d, f) order(reproducible:concurrent)
+#elif OMP5
 #pragma omp target simd if (target:argc > 0) if(simd:argc) nontemporal(argc, c, d) lastprivate(conditional: d, f) order(concurrent)
 #else
 #pragma omp target simd if (target:argc > 0)
-#endif // OMP5
+#endif // OMP51
   for (int i = 0; i < 2; ++i) {}
   // OMP45: #pragma omp target simd if(target: argc > 0)
   // OMP50: #pragma omp target simd if(target: argc > 0) if(simd: argc) nontemporal(argc,c,d) lastprivate(conditional: d,f) order(concurrent)
+  // OMP51: #pragma omp target simd if(target: argc > 0) if(simd: argc) nontemporal(argc,c,d) lastprivate(conditional: d,f) order(reproducible: concurrent)
   // CHECK-NEXT: for (int i = 0; i < 2; ++i) {
   // CHECK-NEXT: }
 
diff --git a/clang/test/OpenMP/target_simd_loop_messages.cpp b/clang/test/OpenMP/target_simd_loop_messages.cpp
--- a/clang/test/OpenMP/target_simd_loop_messages.cpp
+++ b/clang/test/OpenMP/target_simd_loop_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp45 %s -Wno-openmp-mapping -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp50 %s -Wno-openmp-mapping -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp51 %s -Wno-openmp-mapping -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp45 %s -Wno-openmp-mapping -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp50 %s -Wno-openmp-mapping -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp51 %s -Wno-openmp-mapping -Wuninitialized
 
 class S {
   int a;
@@ -94,18 +96,18 @@
   for (((ii)) = 0; ii < 10; ++ii)
     c[ii] = a[ii];
 
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
 #pragma omp target simd
   for (int i = 0; i; i++)
     c[i] = a[i];
 
-// omp45-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+3 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
 // expected-error@+2 {{increment clause of OpenMP for loop must perform simple addition or subtraction on loop variable 'i'}}
 #pragma omp target simd
   for (int i = 0; jj < kk; ii++)
     c[i] = a[i];
 
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
 #pragma omp target simd
   for (int i = 0; !!i; i++)
     c[i] = a[i];
@@ -115,7 +117,7 @@
   for (int i = 0; i != 1; i++)
     c[i] = a[i];
 
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
 #pragma omp target simd
   for (int i = 0;; i++)
     c[i] = a[i];
@@ -420,15 +422,15 @@
 #pragma omp target simd
   for (begin = end; begin < end; ++begin)
     ++begin;
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
 #pragma omp target simd
   for (GoodIter I = begin; I - I; ++I)
     ++I;
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
 #pragma omp target simd
   for (GoodIter I = begin; begin < end; ++I)
     ++I;
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
 #pragma omp target simd
   for (GoodIter I = begin; !I; ++I)
     ++I;
@@ -633,10 +635,10 @@
 #pragma omp target simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -645,4 +647,19 @@
 #pragma omp target simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp target simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target simd'}} omp51-error {{directive '#pragma omp target simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
diff --git a/clang/test/OpenMP/target_teams_distribute_parallel_for_ast_print.cpp b/clang/test/OpenMP/target_teams_distribute_parallel_for_ast_print.cpp
--- a/clang/test/OpenMP/target_teams_distribute_parallel_for_ast_print.cpp
+++ b/clang/test/OpenMP/target_teams_distribute_parallel_for_ast_print.cpp
@@ -1,10 +1,16 @@
-// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping -Wsign-conversion | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping -Wsign-conversion | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
-// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -Wsign-conversion -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
-// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping -Wsign-conversion | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping -Wsign-conversion | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
-// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -Wsign-conversion -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -107,11 +113,16 @@
 // CHECK: #pragma omp target teams distribute parallel for{{$}}
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
 // CHECK-NEXT: a = 2;
+#ifdef OMP51
+#pragma omp target teams distribute parallel for private(argc, b), firstprivate(c, d), collapse(2) order(unconstrained:concurrent)
+#else
 #pragma omp target teams distribute parallel for private(argc, b), firstprivate(c, d), collapse(2) order(concurrent)
+#endif // OMP51
   for (int i = 0; i < 10; ++i)
     for (int j = 0; j < 10; ++j)
       foo();
-// CHECK: #pragma omp target teams distribute parallel for private(argc,b) firstprivate(c,d) collapse(2) order(concurrent)
+// OMP51: #pragma omp target teams distribute parallel for private(argc,b) firstprivate(c,d) collapse(2) order(unconstrained: concurrent)
+// OMP50: #pragma omp target teams distribute parallel for private(argc,b) firstprivate(c,d) collapse(2) order(concurrent)
 // CHECK-NEXT: for (int i = 0; i < 10; ++i)
 // CHECK-NEXT: for (int j = 0; j < 10; ++j)
 // CHECK-NEXT: foo();
diff --git a/clang/test/OpenMP/target_teams_distribute_parallel_for_messages.cpp b/clang/test/OpenMP/target_teams_distribute_parallel_for_messages.cpp
--- a/clang/test/OpenMP/target_teams_distribute_parallel_for_messages.cpp
+++ b/clang/test/OpenMP/target_teams_distribute_parallel_for_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp -fopenmp-version=45 -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp -fopenmp-version=50 -std=c++11 %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp -fopenmp-version=51 -std=c++11 %s -Wuninitialized
 
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp-simd -fopenmp-version=45 -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp-simd -fopenmp-version=50 -std=c++11 %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp-simd -fopenmp-version=51 -std=c++11 %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -102,10 +104,10 @@
 #pragma omp target teams distribute parallel for order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target teams distribute parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target teams distribute parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target teams distribute parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target teams distribute parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target teams distribute parallel for order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -114,5 +116,20 @@
 #pragma omp target teams distribute parallel for order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp target teams distribute parallel for order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute parallel for order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute parallel for order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute parallel for order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute parallel for order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for'}} omp51-error {{directive '#pragma omp target teams distribute parallel for' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_ast_print.cpp b/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_ast_print.cpp
--- a/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_ast_print.cpp
+++ b/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_ast_print.cpp
@@ -1,10 +1,16 @@
-// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
-// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
-// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
-// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -179,11 +185,16 @@
 // CHECK: #pragma omp target teams distribute parallel for simd
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
 // CHECK-NEXT: a = 2;
+#ifdef OMP51
+#pragma omp target teams distribute parallel for simd private(argc,b),firstprivate(argv, c), collapse(2) order(reproducible:concurrent)
+#else
 #pragma omp target teams distribute parallel for simd private(argc,b),firstprivate(argv, c), collapse(2) order(concurrent)
+#endif // OMP51
   for (int i = 0; i < 10; ++i)
     for (int j = 0; j < 10; ++j)
       foo();
-// CHECK: #pragma omp target teams distribute parallel for simd private(argc,b) firstprivate(argv,c) collapse(2) order(concurrent)
+// OMP50: #pragma omp target teams distribute parallel for simd private(argc,b) firstprivate(argv,c) collapse(2) order(concurrent)
+// OMP51: #pragma omp target teams distribute parallel for simd private(argc,b) firstprivate(argv,c) collapse(2) order(reproducible: concurrent)
 // CHECK-NEXT: for (int i = 0; i < 10; ++i)
 // CHECK-NEXT: for (int j = 0; j < 10; ++j)
 // CHECK-NEXT: foo();
diff --git a/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_loop_messages.cpp b/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_loop_messages.cpp
--- a/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_loop_messages.cpp
+++ b/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_loop_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp45 %s -Wno-openmp-mapping -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp50 %s -Wno-openmp-mapping -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp51 %s -Wno-openmp-mapping -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp45 %s -Wno-openmp-mapping -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp50 %s -Wno-openmp-mapping -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -fexceptions -fcxx-exceptions -verify=expected,omp51 %s -Wno-openmp-mapping -Wuninitialized
 
 class S {
   int a;
@@ -95,18 +97,18 @@
     c[ii] = a[ii];
 
 #pragma omp target teams distribute parallel for simd
-// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
   for (int i = 0; i; i++)
     c[i] = a[i];
 
 #pragma omp target teams distribute parallel for simd
-// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+2 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
 // expected-error@+1 {{increment clause of OpenMP for loop must perform simple addition or subtraction on loop variable 'i'}}
   for (int i = 0; jj < kk; ii++)
     c[i] = a[i];
 
 #pragma omp target teams distribute parallel for simd
-// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
   for (int i = 0; !!i; i++)
     c[i] = a[i];
 
@@ -116,7 +118,7 @@
     c[i] = a[i];
 
 #pragma omp target teams distribute parallel for simd
-// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
+// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'i'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}} omp51-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'i'}}
   for (int i = 0;; i++)
     c[i] = a[i];
 
@@ -406,15 +408,15 @@
   for (begin = end; begin < end; ++begin)
     ++begin;
 #pragma omp target teams distribute parallel for simd
-// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
+// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}} omp51-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
   for (GoodIter I = begin; I - I; ++I)
     ++I;
 #pragma omp target teams distribute parallel for simd
-// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
+// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}} omp51-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
   for (GoodIter I = begin; begin < end; ++I)
     ++I;
 #pragma omp target teams distribute parallel for simd
-// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
+// omp45-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', or '>=') of loop variable 'I'}} omp50-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}} omp51-error@+1 {{condition of OpenMP for loop must be a relational comparison ('<', '<=', '>', '>=', or '!=') of loop variable 'I'}}
   for (GoodIter I = begin; !I; ++I)
     ++I;
 #pragma omp target teams distribute parallel for simd
@@ -631,10 +633,10 @@
 #pragma omp target teams distribute parallel for simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target teams distribute parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target teams distribute parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target teams distribute parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target teams distribute parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target teams distribute parallel for simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -643,5 +645,20 @@
 #pragma omp target teams distribute parallel for simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp target teams distribute parallel for simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute parallel for simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute parallel for simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute parallel for simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute parallel for simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute parallel for simd'}} omp51-error {{directive '#pragma omp target teams distribute parallel for simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/target_teams_distribute_simd_ast_print.cpp b/clang/test/OpenMP/target_teams_distribute_simd_ast_print.cpp
--- a/clang/test/OpenMP/target_teams_distribute_simd_ast_print.cpp
+++ b/clang/test/OpenMP/target_teams_distribute_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -DOMP5 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -DOMP51 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=45 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP45
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -DOMP5 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -DOMP51 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s -Wno-openmp-mapping
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -208,15 +214,18 @@
 // CHECK: #pragma omp target teams distribute simd simdlen(clen - 1)
 // CHECK-NEXT: for (int k = 0; k < 10; ++k)
 // CHECK-NEXT: e += d + argc;
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp target teams distribute simd safelen(clen-1) aligned(arr:N+6) if(simd:argc) nontemporal(argc, c, d) order(unconstrained:concurrent) allocate(omp_low_lat_mem_alloc:e) firstprivate(e) uses_allocators(omp_low_lat_mem_alloc)
+#elif OMP5
 #pragma omp target teams distribute simd safelen(clen-1) aligned(arr:N+6) if(simd:argc) nontemporal(argc, c, d) order(concurrent) allocate(omp_low_lat_mem_alloc:e) firstprivate(e) uses_allocators(omp_low_lat_mem_alloc)
 #else
 #pragma omp target teams distribute simd safelen(clen-1) aligned(arr:N+6)
-#endif // OMP5
+#endif // OMP51
   for (int k = 0; k < 10; ++k)
     e += d + argc + arr[k];
 // OMP45: #pragma omp target teams distribute simd safelen(clen - 1) aligned(arr: N + 6)
 // OMP50: #pragma omp target teams distribute simd safelen(clen - 1) aligned(arr: N + 6) if(simd: argc) nontemporal(argc,c,d) order(concurrent) allocate(omp_low_lat_mem_alloc: e) firstprivate(e) uses_allocators(omp_low_lat_mem_alloc)
+// OMP51: #pragma omp target teams distribute simd safelen(clen - 1) aligned(arr: N + 6) if(simd: argc) nontemporal(argc,c,d) order(unconstrained: concurrent) allocate(omp_low_lat_mem_alloc: e) firstprivate(e) uses_allocators(omp_low_lat_mem_alloc)
 // CHECK-NEXT: for (int k = 0; k < 10; ++k)
 // CHECK-NEXT: e += d + argc + arr[k];
   return (0);
diff --git a/clang/test/OpenMP/target_teams_distribute_simd_misc_messages.c b/clang/test/OpenMP/target_teams_distribute_simd_misc_messages.c
--- a/clang/test/OpenMP/target_teams_distribute_simd_misc_messages.c
+++ b/clang/test/OpenMP/target_teams_distribute_simd_misc_messages.c
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=50 -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=50 -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 // expected-error@+1 {{unexpected OpenMP directive '#pragma omp target teams distribute simd'}}
 #pragma omp target teams distribute simd
@@ -343,7 +345,7 @@
 #pragma omp target teams distribute simd nontemporal(int)
   for (i = 0; i < 16; ++i)
     ;
-// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp target teams distribute simd'}} omp50-error@+1 {{expected variable name}}
+// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp target teams distribute simd'}} omp50-error@+1 {{expected variable name}} omp51-error@+1 {{expected variable name}}
 #pragma omp target teams distribute simd nontemporal(0)
   for (i = 0; i < 16; ++i)
     ;
@@ -373,8 +375,9 @@
   for (i = 0; i < 16; ++i)
     ;
 
+// omp51-note@+3 {{defined as nontemporal}}
 // omp50-note@+2 {{defined as nontemporal}}
-// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp target teams distribute simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
+// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp target teams distribute simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}} omp51-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
 #pragma omp target teams distribute simd nontemporal(x) nontemporal(x)
   for (i = 0; i < 16; ++i)
     ;
@@ -406,10 +409,10 @@
 #pragma omp target teams distribute simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target teams distribute simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target teams distribute simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp target teams distribute simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp target teams distribute simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target teams distribute simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -418,5 +421,20 @@
 #pragma omp target teams distribute simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp target teams distribute simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target teams distribute simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp target teams distribute simd'}} omp51-error {{directive '#pragma omp target teams distribute simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/taskloop_simd_ast_print.cpp b/clang/test/OpenMP/taskloop_simd_ast_print.cpp
--- a/clang/test/OpenMP/taskloop_simd_ast_print.cpp
+++ b/clang/test/OpenMP/taskloop_simd_ast_print.cpp
@@ -1,16 +1,16 @@
 // RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -DOMP5 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix CHECK --check-prefix OMP50
-// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
-// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
-// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -DOMP51 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -DOMP5 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix CHECK --check-prefix OMP50
-// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
-// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP5
-// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -DOMP5 | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -DOMP51 -ast-print %s | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -75,16 +75,19 @@
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
 // CHECK-NEXT: a = 2;
 #pragma omp parallel
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp taskloop simd private(argc, b), firstprivate(argv, c), lastprivate(d, f) collapse(2) shared(g) if(simd: argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a, e) nontemporal(argc, c, d) order(reproducible:concurrent)
+#elif OMP5
 #pragma omp taskloop simd private(argc, b), firstprivate(argv, c), lastprivate(d, f) collapse(2) shared(g) if(simd: argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a, e) nontemporal(argc, c, d) order(concurrent)
 #else
 #pragma omp taskloop simd private(argc, b), firstprivate(argv, c), lastprivate(d, f) collapse(2) shared(g) if(argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a, e)
-#endif // OMP5
+#endif // OMP51
   for (int i = 0; i < 10; ++i)
     for (int j = 0; j < 10; ++j)
       foo();
   // CHECK-NEXT: #pragma omp parallel
   // OMP50-NEXT: #pragma omp taskloop simd private(argc,b) firstprivate(argv,c) lastprivate(d,f) collapse(2) shared(g) if(simd: argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a,e) nontemporal(argc,c,d) order(concurrent)
+  // OMP51-NEXT: #pragma omp taskloop simd private(argc,b) firstprivate(argv,c) lastprivate(d,f) collapse(2) shared(g) if(simd: argc) mergeable priority(argc) simdlen(16) grainsize(argc) reduction(max: a,e) nontemporal(argc,c,d) order(reproducible: concurrent)
   // CHECK-NEXT: for (int i = 0; i < 10; ++i)
   // CHECK-NEXT: for (int j = 0; j < 10; ++j)
   // CHECK-NEXT: foo();
diff --git a/clang/test/OpenMP/taskloop_simd_misc_messages.c b/clang/test/OpenMP/taskloop_simd_misc_messages.c
--- a/clang/test/OpenMP/taskloop_simd_misc_messages.c
+++ b/clang/test/OpenMP/taskloop_simd_misc_messages.c
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -triple x86_64-unknown-unknown -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -triple x86_64-unknown-unknown -fopenmp-version=50 -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -triple x86_64-unknown-unknown -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -triple x86_64-unknown-unknown -fopenmp-version=45 -verify=expected,omp45 %s -Wuninitialized
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -triple x86_64-unknown-unknown -fopenmp-version=50 -verify=expected,omp50 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -triple x86_64-unknown-unknown -fopenmp-version=51 -verify=expected,omp51 %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -407,7 +409,7 @@
 #pragma omp taskloop simd nontemporal(int)
   for (i = 0; i < 16; ++i)
     ;
-// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp taskloop simd'}} omp50-error@+1 {{expected variable name}}
+// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp taskloop simd'}} omp50-error@+1 {{expected variable name}} omp51-error@+1 {{expected variable name}}
 #pragma omp taskloop simd nontemporal(0)
   for (i = 0; i < 16; ++i)
     ;
@@ -437,8 +439,9 @@
   for (i = 0; i < 16; ++i)
     ;
 
+// omp51-note@+3 {{defined as nontemporal}}
 // omp50-note@+2 {{defined as nontemporal}}
-// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp taskloop simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
+// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp taskloop simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}} omp51-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
 #pragma omp taskloop simd nontemporal(x) nontemporal(x)
   for (i = 0; i < 16; ++i)
     ;
@@ -470,10 +473,10 @@
 #pragma omp taskloop simd order // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} expected-error {{expected '(' after 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp taskloop simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp taskloop simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
-#pragma omp taskloop simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp taskloop simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp taskloop simd order(concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
@@ -482,5 +485,20 @@
 #pragma omp taskloop simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp taskloop simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp taskloop simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp taskloop simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp taskloop simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp taskloop simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp taskloop simd'}} omp51-error {{directive '#pragma omp taskloop simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/teams_distribute_parallel_for_ast_print.cpp b/clang/test/OpenMP/teams_distribute_parallel_for_ast_print.cpp
--- a/clang/test/OpenMP/teams_distribute_parallel_for_ast_print.cpp
+++ b/clang/test/OpenMP/teams_distribute_parallel_for_ast_print.cpp
@@ -1,10 +1,16 @@
-// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
-// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s -DOMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping -DOMP51 | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -112,12 +118,17 @@
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
 // CHECK-NEXT: a = 2;
 #pragma omp target
+#ifdef OMP51
+#pragma omp teams distribute parallel for private(argc, b), firstprivate(c, d), collapse(2) order(unconstrained:concurrent)
+#else
 #pragma omp teams distribute parallel for private(argc, b), firstprivate(c, d), collapse(2) order(concurrent)
+#endif // OMP51
   for (int i = 0; i < 10; ++i)
     for (int j = 0; j < 10; ++j)
       foo();
 // CHECK: #pragma omp target
-// CHECK-NEXT: #pragma omp teams distribute parallel for private(argc,b) firstprivate(c,d) collapse(2) order(concurrent)
+// OMP50: #pragma omp teams distribute parallel for private(argc,b) firstprivate(c,d) collapse(2) order(concurrent)
+// OMP51: #pragma omp teams distribute parallel for private(argc,b) firstprivate(c,d) collapse(2) order(unconstrained: concurrent)
 // CHECK-NEXT: for (int i = 0; i < 10; ++i)
 // CHECK-NEXT: for (int j = 0; j < 10; ++j)
 // CHECK-NEXT: foo();
diff --git a/clang/test/OpenMP/teams_distribute_parallel_for_messages.cpp b/clang/test/OpenMP/teams_distribute_parallel_for_messages.cpp
--- a/clang/test/OpenMP/teams_distribute_parallel_for_messages.cpp
+++ b/clang/test/OpenMP/teams_distribute_parallel_for_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp -fopenmp-version=45 -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp -fopenmp-version=50 -std=c++11 %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp -fopenmp-version=51 -std=c++11 %s -Wuninitialized
 
 // RUN: %clang_cc1 -verify=expected,omp45 -fopenmp-simd -fopenmp-version=45 -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,omp50 -fopenmp-simd -fopenmp-version=50 -std=c++11 %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp51 -fopenmp-simd -fopenmp-version=51 -std=c++11 %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -125,11 +127,11 @@
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target
-#pragma omp teams distribute parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp teams distribute parallel for order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target
-#pragma omp teams distribute parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp teams distribute parallel for order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target
@@ -140,6 +142,26 @@
 #pragma omp teams distribute parallel for order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp target
+#pragma omp teams distribute parallel for order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute parallel for order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute parallel for order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute parallel for order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute parallel for order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for'}} omp51-error {{directive '#pragma omp teams distribute parallel for' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
 void test_cancel() {
diff --git a/clang/test/OpenMP/teams_distribute_parallel_for_simd_ast_print.cpp b/clang/test/OpenMP/teams_distribute_parallel_for_simd_ast_print.cpp
--- a/clang/test/OpenMP/teams_distribute_parallel_for_simd_ast_print.cpp
+++ b/clang/test/OpenMP/teams_distribute_parallel_for_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -DOMP5 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -DOMP51 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP45
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -DOMP5 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -DOMP51 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix CHECK --check-prefix OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -156,16 +162,19 @@
 // CHECK: for (int i = 0; i < 10; ++i)
 // CHECK-NEXT: foo();
 #pragma omp target
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp teams distribute parallel for simd if(simd:argc) nontemporal(argc, c, d) order(reproducible:concurrent)
+#elif OMP5
 #pragma omp teams distribute parallel for simd if(simd:argc) nontemporal(argc, c, d) order(concurrent)
 #else
 #pragma omp teams distribute parallel for simd
-#endif // OMP5
+#endif // OMP51
   for (int i = 0; i < 10; ++i)
     foo();
 // CHECK: #pragma omp target
 // OMP45-NEXT: #pragma omp teams distribute parallel for simd
 // OMP50-NEXT: #pragma omp teams distribute parallel for simd if(simd: argc) nontemporal(argc,c,d) order(concurrent)
+// OMP51-NEXT: #pragma omp teams distribute parallel for simd if(simd: argc) nontemporal(argc,c,d) order(reproducible: concurrent)
 // CHECK-NEXT: for (int i = 0; i < 10; ++i)
 // CHECK-NEXT: foo();
 #pragma omp target
diff --git a/clang/test/OpenMP/teams_distribute_parallel_for_simd_messages.cpp b/clang/test/OpenMP/teams_distribute_parallel_for_simd_messages.cpp
--- a/clang/test/OpenMP/teams_distribute_parallel_for_simd_messages.cpp
+++ b/clang/test/OpenMP/teams_distribute_parallel_for_simd_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=45 -verify=expected,omp45 -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -verify=expected,omp50 -std=c++11 %s -Wuninitialized
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -verify=expected,omp51 -std=c++11 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -verify=expected,omp45 -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -verify=expected,omp50 -std=c++11 %s -Wuninitialized
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -verify=expected,omp51 -std=c++11 %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -150,7 +152,7 @@
   for (i = 0; i < 16; ++i)
     ;
 #pragma omp target
-// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp teams distribute parallel for simd'}} omp50-error@+1 {{expected variable name}}
+// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp teams distribute parallel for simd'}} omp50-error@+1 {{expected variable name}} omp51-error@+1 {{expected variable name}}
 #pragma omp teams distribute parallel for simd nontemporal(0)
   for (i = 0; i < 16; ++i)
     ;
@@ -186,8 +188,9 @@
     ;
 
 #pragma omp target
+// omp51-note@+3 {{defined as nontemporal}}
 // omp50-note@+2 {{defined as nontemporal}}
-// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp teams distribute parallel for simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
+// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp teams distribute parallel for simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}} omp51-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
 #pragma omp teams distribute parallel for simd nontemporal(x) nontemporal(x)
   for (i = 0; i < 16; ++i)
     ;
@@ -226,11 +229,11 @@
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target
-#pragma omp teams distribute parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp teams distribute parallel for simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target
-#pragma omp teams distribute parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp teams distribute parallel for simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target
@@ -241,5 +244,25 @@
 #pragma omp teams distribute parallel for simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp target
+#pragma omp teams distribute parallel for simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute parallel for simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute parallel for simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute parallel for simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute parallel for simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute parallel for simd'}} omp51-error {{directive '#pragma omp teams distribute parallel for simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }
 
diff --git a/clang/test/OpenMP/teams_distribute_simd_ast_print.cpp b/clang/test/OpenMP/teams_distribute_simd_ast_print.cpp
--- a/clang/test/OpenMP/teams_distribute_simd_ast_print.cpp
+++ b/clang/test/OpenMP/teams_distribute_simd_ast_print.cpp
@@ -4,6 +4,9 @@
 // RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -DOMP5 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -DOMP51 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 
 // RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP45
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s
@@ -11,6 +14,9 @@
 // RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -DOMP5 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -DOMP5 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP50
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -DOMP51 -ast-print %s -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -DOMP51 -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print -Wno-openmp-mapping | FileCheck %s --check-prefix=CHECK --check-prefix=OMP51
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -242,16 +248,19 @@
 // CHECK-NEXT: for (int k = 0; k < 10; ++k)
 // CHECK-NEXT: e += d + argc;
 #pragma omp target
-#ifdef OMP5
+#ifdef OMP51
+#pragma omp teams distribute simd safelen(clen-1) aligned(arr:N+6) if(simd:b) nontemporal(argc, c, d) order(unconstrained:concurrent)
+#elif OMP5
 #pragma omp teams distribute simd safelen(clen-1) aligned(arr:N+6) if(simd:b) nontemporal(argc, c, d) order(concurrent)
 #else
 #pragma omp teams distribute simd safelen(clen-1) aligned(arr:N+6)
-#endif
+#endif // OMP51
   for (int k = 0; k < 10; ++k)
     e += d + argc + arr[k];
 // CHECK: #pragma omp target
 // OMP45-NEXT: #pragma omp teams distribute simd safelen(clen - 1) aligned(arr: N + 6)
 // OMP50-NEXT: #pragma omp teams distribute simd safelen(clen - 1) aligned(arr: N + 6) if(simd: b) nontemporal(argc,c,d) order(concurrent)
+// OMP51-NEXT: #pragma omp teams distribute simd safelen(clen - 1) aligned(arr: N + 6) if(simd: b) nontemporal(argc,c,d) order(unconstrained: concurrent)
 // CHECK-NEXT: for (int k = 0; k < 10; ++k)
 // CHECK-NEXT: e += d + argc + arr[k];
   return (0);
diff --git a/clang/test/OpenMP/teams_distribute_simd_messages.cpp b/clang/test/OpenMP/teams_distribute_simd_messages.cpp
--- a/clang/test/OpenMP/teams_distribute_simd_messages.cpp
+++ b/clang/test/OpenMP/teams_distribute_simd_messages.cpp
@@ -1,8 +1,10 @@
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=45 -verify=expected,omp45 -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -verify=expected,omp50 -std=c++11 %s -Wuninitialized
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -verify=expected,omp51 -std=c++11 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=45 -verify=expected,omp45 -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -verify=expected,omp50 -std=c++11 %s -Wuninitialized
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -verify=expected,omp51 -std=c++11 %s -Wuninitialized
 
 void xxx(int argc) {
   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
@@ -150,7 +152,7 @@
   for (i = 0; i < 16; ++i)
     ;
 #pragma omp target
-// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp teams distribute simd'}} omp50-error@+1 {{expected variable name}}
+// omp45-error@+1 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp teams distribute simd'}} omp50-error@+1 {{expected variable name}} omp51-error@+1 {{expected variable name}}
 #pragma omp teams distribute simd nontemporal(0)
   for (i = 0; i < 16; ++i)
     ;
@@ -186,8 +188,9 @@
     ;
 
 #pragma omp target
+// omp51-note@+3 {{defined as nontemporal}}
 // omp50-note@+2 {{defined as nontemporal}}
-// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp teams distribute simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
+// omp45-error@+1 2 {{unexpected OpenMP clause 'nontemporal' in directive '#pragma omp teams distribute simd'}} omp50-error@+1 {{a variable cannot appear in more than one nontemporal clause}} omp51-error@+1 {{a variable cannot appear in more than one nontemporal clause}}
 #pragma omp teams distribute simd nontemporal(x) nontemporal(x)
   for (i = 0; i < 16; ++i)
     ;
@@ -226,11 +229,11 @@
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target
-#pragma omp teams distribute simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp teams distribute simd order( // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target
-#pragma omp teams distribute simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+#pragma omp teams distribute simd order(none // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i)
     ;
 #pragma omp target
@@ -241,5 +244,25 @@
 #pragma omp teams distribute simd order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}}
   for (int i = 0; i < 10; ++i)
     ;
+#pragma omp target
+#pragma omp teams distribute simd order(unconstrained:) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}} omp51-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute simd order(reproducible:concurrent // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} expected-error {{expected ')'}} expected-note {{to match this '('}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute simd order(reproducible:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute simd order(unconstrained:concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
+  for (int i = 0; i < 10; ++i)
+    ;
+#pragma omp target
+#pragma omp teams distribute simd order(concurrent) order(concurrent) // omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} omp45-error {{unexpected OpenMP clause 'order' in directive '#pragma omp teams distribute simd'}} omp51-error {{directive '#pragma omp teams distribute simd' cannot contain more than one 'order' clause}}
+  for (int i = 0; i < 10; ++i)
+    ;
 }