Index: flang/docs/Extensions.md
===================================================================
--- flang/docs/Extensions.md
+++ flang/docs/Extensions.md
@@ -350,6 +350,19 @@
   pointer-valued function reference.
   No other Fortran compiler seems to handle this correctly for
   `ASSOCIATE`, though NAG gets it right for `SELECT TYPE`.
+* The standard doesn't explicitly require that a named constant that
+  appears as part of a complex-literal-constant be a scalar, but
+  most compilers emit an error when an array appears.
+  f18 supports them with a portability warning.
+* f18 does not enforce a blanket prohibition against generic
+  interfaces containing a mixture of functions and subroutines.
+  Apart from some contexts in which the standard requires all of
+  a particular generic interface to have only all functions or
+  all subroutines as its specific procedures, we allow both to
+  appear, unlike several other Fortran compilers.
+  This is especially desirable when two generics of the same
+  name are combined due to USE association and the mixture may
+  be inadvertent.
 
 ## Behavior in cases where the standard is ambiguous or indefinite
 
Index: flang/include/flang/Semantics/expression.h
===================================================================
--- flang/include/flang/Semantics/expression.h
+++ flang/include/flang/Semantics/expression.h
@@ -349,7 +349,8 @@
   std::pair<const Symbol *, bool /* failure due to NULL() actuals */>
   ResolveGeneric(const Symbol &, const ActualArguments &, const AdjustActuals &,
       bool isSubroutine, bool mightBeStructureConstructor = false);
-  void EmitGenericResolutionError(const Symbol &, bool dueToNullActuals);
+  void EmitGenericResolutionError(
+      const Symbol &, bool dueToNullActuals, bool isSubroutine);
   const Symbol &AccessSpecific(
       const Symbol &originalGeneric, const Symbol &specific);
   std::optional<CalleeAndArguments> GetCalleeAndArguments(const parser::Name &,
Index: flang/lib/Semantics/expression.cpp
===================================================================
--- flang/lib/Semantics/expression.cpp
+++ flang/lib/Semantics/expression.cpp
@@ -174,8 +174,8 @@
   std::optional<ActualArgument> AnalyzeExpr(const parser::Expr &);
   MaybeExpr AnalyzeExprOrWholeAssumedSizeArray(const parser::Expr &);
   bool AreConformable() const;
-  const Symbol *FindBoundOp(
-      parser::CharBlock, int passIndex, const Symbol *&definedOp);
+  const Symbol *FindBoundOp(parser::CharBlock, int passIndex,
+      const Symbol *&definedOp, bool isSubroutine);
   void AddAssignmentConversion(
       const DynamicType &lhsType, const DynamicType &rhsType);
   bool OkLogicalIntegerAssignment(TypeCategory lhs, TypeCategory rhs);
@@ -2045,7 +2045,8 @@
             // re-resolve the name to the specific binding
             sc.component.symbol = const_cast<Symbol *>(sym);
           } else {
-            EmitGenericResolutionError(*sc.component.symbol, pair.second);
+            EmitGenericResolutionError(
+                *sc.component.symbol, pair.second, isSubroutine);
             return std::nullopt;
           }
         }
@@ -2190,6 +2191,9 @@
           return IsBareNullPointer(iter->UnwrapExpr());
         }) != actuals.end()};
     for (const Symbol &specific : details->specificProcs()) {
+      if (isSubroutine != !IsFunction(specific)) {
+        continue;
+      }
       if (!ResolveForward(specific)) {
         continue;
       }
@@ -2294,12 +2298,14 @@
 }
 
 void ExpressionAnalyzer::EmitGenericResolutionError(
-    const Symbol &symbol, bool dueToNullActuals) {
+    const Symbol &symbol, bool dueToNullActuals, bool isSubroutine) {
   Say(dueToNullActuals
           ? "One or more NULL() actual arguments to the generic procedure '%s' requires a MOLD= for disambiguation"_err_en_US
           : semantics::IsGenericDefinedOp(symbol)
           ? "No specific procedure of generic operator '%s' matches the actual arguments"_err_en_US
-          : "No specific procedure of generic '%s' matches the actual arguments"_err_en_US,
+          : isSubroutine
+          ? "No specific subroutine of generic '%s' matches the actual arguments"_err_en_US
+          : "No specific function of generic '%s' matches the actual arguments"_err_en_US,
       symbol.name());
 }
 
@@ -2362,7 +2368,7 @@
           std::move(specificCall->arguments)};
     } else {
       if (isGenericInterface) {
-        EmitGenericResolutionError(*symbol, dueToNullActual);
+        EmitGenericResolutionError(*symbol, dueToNullActual, isSubroutine);
       }
       return std::nullopt;
     }
@@ -3587,7 +3593,7 @@
     }
     for (std::size_t passIndex{0}; passIndex < actuals_.size(); ++passIndex) {
       if (const Symbol *
-          symbol{FindBoundOp(oprName, passIndex, *definedOpSymbolPtr)}) {
+          symbol{FindBoundOp(oprName, passIndex, *definedOpSymbolPtr, false)}) {
         if (MaybeExpr result{TryBoundOp(*symbol, passIndex)}) {
           return result;
         }
@@ -3705,13 +3711,14 @@
     if (pair.first) {
       proc = pair.first;
     } else {
-      context_.EmitGenericResolutionError(*symbol, pair.second);
+      context_.EmitGenericResolutionError(*symbol, pair.second, true);
     }
   }
   int passedObjectIndex{-1};
   const Symbol *definedOpSymbol{nullptr};
   for (std::size_t i{0}; i < actuals_.size(); ++i) {
-    if (const Symbol * specific{FindBoundOp(oprName, i, definedOpSymbol)}) {
+    if (const Symbol *
+        specific{FindBoundOp(oprName, i, definedOpSymbol, true)}) {
       if (const Symbol *
           resolution{GetBindingResolution(GetType(i), *specific)}) {
         proc = resolution;
@@ -3794,8 +3801,8 @@
 }
 
 // Look for a type-bound operator in the type of arg number passIndex.
-const Symbol *ArgumentAnalyzer::FindBoundOp(
-    parser::CharBlock oprName, int passIndex, const Symbol *&definedOp) {
+const Symbol *ArgumentAnalyzer::FindBoundOp(parser::CharBlock oprName,
+    int passIndex, const Symbol *&definedOp, bool isSubroutine) {
   const auto *type{GetDerivedTypeSpec(GetType(passIndex))};
   if (!type || !type->scope()) {
     return nullptr;
@@ -3809,9 +3816,10 @@
       [&](const Symbol &proc, ActualArguments &) {
         return passIndex == GetPassIndex(proc);
       }};
-  auto pair{context_.ResolveGeneric(*symbol, actuals_, adjustment, false)};
+  auto pair{
+      context_.ResolveGeneric(*symbol, actuals_, adjustment, isSubroutine)};
   if (!pair.first) {
-    context_.EmitGenericResolutionError(*symbol, pair.second);
+    context_.EmitGenericResolutionError(*symbol, pair.second, isSubroutine);
   }
   return pair.first;
 }
Index: flang/lib/Semantics/resolve-names.cpp
===================================================================
--- flang/lib/Semantics/resolve-names.cpp
+++ flang/lib/Semantics/resolve-names.cpp
@@ -3245,9 +3245,8 @@
   specificProcs_.erase(range.first, range.second);
 }
 
-// Check that the specific procedures are all functions or all subroutines.
-// If there is a derived type with the same name they must be functions.
-// Set the corresponding flag on generic.
+// Mixed interfaces are allowed by the standard.
+// If there is a derived type with the same name, they must all be functions.
 void InterfaceVisitor::CheckGenericProcedures(Symbol &generic) {
   ResolveSpecificsInGeneric(generic);
   auto &details{generic.get<GenericDetails>()};
@@ -3270,10 +3269,11 @@
   }
   const Symbol &firstSpecific{specifics.front()};
   bool isFunction{firstSpecific.test(Symbol::Flag::Function)};
+  bool isBoth{false};
   for (const Symbol &specific : specifics) {
     if (isFunction != specific.test(Symbol::Flag::Function)) { // C1514
       auto &msg{Say(generic.name(),
-          "Generic interface '%s' has both a function and a subroutine"_err_en_US)};
+          "Generic interface '%s' has both a function and a subroutine"_warn_en_US)};
       if (isFunction) {
         msg.Attach(firstSpecific.name(), "Function declaration"_en_US);
         msg.Attach(specific.name(), "Subroutine declaration"_en_US);
@@ -3281,6 +3281,9 @@
         msg.Attach(firstSpecific.name(), "Subroutine declaration"_en_US);
         msg.Attach(specific.name(), "Function declaration"_en_US);
       }
+      isFunction = false;
+      isBoth = true;
+      break;
     }
   }
   if (!isFunction && details.derivedType()) {
@@ -3289,7 +3292,9 @@
         " with same name"_err_en_US,
         *details.derivedType()->GetUltimate().scope());
   }
-  generic.set(isFunction ? Symbol::Flag::Function : Symbol::Flag::Subroutine);
+  if (!isBoth) {
+    generic.set(isFunction ? Symbol::Flag::Function : Symbol::Flag::Subroutine);
+  }
 }
 
 // SubprogramVisitor implementation
Index: flang/test/Semantics/generic03.f90
===================================================================
--- /dev/null
+++ flang/test/Semantics/generic03.f90
@@ -0,0 +1,34 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1
+! Exercise function vs subroutine distinction in generics
+module m1
+  type t1
+    integer n
+  end type
+  interface g1
+    integer function f1(x, j)
+      import t1
+      class(t1), intent(in out) :: x
+      integer, intent(in) :: j
+    end
+  end interface
+end module
+
+program test
+  use m1
+  !WARNING: Generic interface 'g1' has both a function and a subroutine
+  interface g1
+    subroutine s1(x, a)
+      import t1
+      class(t1), intent(in out) :: x
+      real, intent(in) :: a
+    end subroutine
+  end interface
+  type(t1) :: x
+  print *, g1(x,1) ! ok
+  !ERROR: No specific function of generic 'g1' matches the actual arguments
+  print *, g1(x,1.)
+  !ERROR: No specific subroutine of generic 'g1' matches the actual arguments
+  call g1(x,1)
+  call g1(x, 1.) ! ok
+ contains
+end
Index: flang/test/Semantics/resolve62.f90
===================================================================
--- flang/test/Semantics/resolve62.f90
+++ flang/test/Semantics/resolve62.f90
@@ -10,7 +10,7 @@
   end interface
   z = f(1.0)
   z = f(1.0, 2.0)
-  !ERROR: No specific procedure of generic 'f' matches the actual arguments
+  !ERROR: No specific function of generic 'f' matches the actual arguments
   z = f(1.0, 2.0, 3.0)
 end
 
Index: flang/test/Semantics/resolve68.f90
===================================================================
--- flang/test/Semantics/resolve68.f90
+++ flang/test/Semantics/resolve68.f90
@@ -21,14 +21,14 @@
     type(t) :: x
     integer :: y
     integer :: z
-    !ERROR: No specific procedure of generic 'g' matches the actual arguments
+    !ERROR: No specific function of generic 'g' matches the actual arguments
     z = x%g(y)
   end
   subroutine test2(x, y, z)
     type(t) :: x
     real :: y
     integer :: z
-    !ERROR: No specific procedure of generic 'g' matches the actual arguments
+    !ERROR: No specific function of generic 'g' matches the actual arguments
     z = x%g(x, y)
   end
 end
Index: flang/test/Semantics/resolve77.f90
===================================================================
--- flang/test/Semantics/resolve77.f90
+++ flang/test/Semantics/resolve77.f90
@@ -10,7 +10,7 @@
   end interface
   !ERROR: Automatic data object 'a' may not appear in the specification part of a module
   real :: a(if1(1))
-  !ERROR: No specific procedure of generic 'ifn2' matches the actual arguments
+  !ERROR: No specific function of generic 'ifn2' matches the actual arguments
   real :: b(ifn2(1))
  contains
   subroutine t1(n)