Index: gcc/fortran/invoke.texi
===================================================================
--- gcc/fortran/invoke.texi	(revision 252892)
+++ gcc/fortran/invoke.texi	(working copy)
@@ -120,7 +120,7 @@ by type.  Explanations are in the following sectio
 -fd-lines-as-comments @gol
 -fdec -fdec-structure -fdec-intrinsic-ints -fdec-static -fdec-math @gol
 -fdefault-double-8 -fdefault-integer-8 @gol
--fdefault-real-8 -fdollar-ok -ffixed-line-length-@var{n} @gol
+-fdefault-real-8 -fdefault-real-16 -fdollar-ok -ffixed-line-length-@var{n} @gol
 -ffixed-line-length-none -ffree-form -ffree-line-length-@var{n} @gol
 -ffree-line-length-none -fimplicit-none -finteger-4-integer-8 @gol
 -fmax-identifier-length -fmodule-private -ffixed-form -fno-range-check @gol
@@ -404,6 +404,14 @@ the default width of @code{DOUBLE PRECISION} to 16
 @code{-fdefault-double-8} is given, too. Unlike @option{-freal-4-real-8},
 it does not promote variables with explicit kind declaration.
 
+@item -fdefault-real-16
+@opindex @code{fdefault-real-16}
+Set the default real type to a 16 byte wide type. This option also affects
+the kind of non-double real constants like @code{1.0}, and does promote
+the default width of @code{DOUBLE PRECISION} to 16 bytes if possible, unless
+@code{-fdefault-double-8} is given. Unlike @option{-freal-4-real-16},
+it does not promote variables with explicit kind declaration.
+
 @item -fdefault-double-8
 @opindex @code{fdefault-double-8}
 Set the @code{DOUBLE PRECISION} type to an 8 byte wide type.  Do nothing if this
Index: gcc/fortran/lang.opt
===================================================================
--- gcc/fortran/lang.opt	(revision 252892)
+++ gcc/fortran/lang.opt	(working copy)
@@ -460,6 +460,10 @@ fdefault-real-8
 Fortran Var(flag_default_real)
 Set the default real kind to an 8 byte wide type.
 
+fdefault-real-16
+Fortran Var(flag_default_real_16)
+Set the default real kind to an 16 byte wide type.
+
 fdollar-ok
 Fortran Var(flag_dollar_ok)
 Allow dollar signs in entity names.
Index: gcc/fortran/trans-types.c
===================================================================
--- gcc/fortran/trans-types.c	(revision 252892)
+++ gcc/fortran/trans-types.c	(working copy)
@@ -538,6 +538,14 @@ gfc_init_kinds (void)
 
       gfc_default_real_kind = 8;
     }
+  else if (flag_default_real_16)
+  {
+    if (!saw_r16)
+      gfc_fatal_error ("REAL(KIND=16) is not available for "
+			"%<-fdefault-real-16%> option");
+
+    gfc_default_real_kind = 16;
+  }
   else if (flag_real4_kind == 8)
   {
     if (!saw_r8)
@@ -577,7 +585,7 @@ gfc_init_kinds (void)
 
   if (flag_default_real && flag_default_double && saw_r8)
     gfc_default_double_kind = 8;
-  else if (flag_default_real && saw_r16)
+  else if ((flag_default_real || flag_default_real_16) && saw_r16)
     gfc_default_double_kind = 16;
   else if (flag_real8_kind == 4)
     {