diff --git a/gcc/ada/gcc-interface/misc.c b/gcc/ada/gcc-interface/misc.c
index 4bb22ed..cef8d84 100644
--- a/gcc/ada/gcc-interface/misc.c
+++ b/gcc/ada/gcc-interface/misc.c
@@ -1278,11 +1278,11 @@ enumerate_modes (void (*f) (const char *, int, int, int, int, int, int, int))
 int
 fp_prec_to_size (int prec)
 {
-  machine_mode mode;
+  opt_scalar_float_mode mode;
 
   FOR_EACH_MODE_IN_CLASS (mode, MODE_FLOAT)
-    if (GET_MODE_PRECISION (mode) == prec)
-      return GET_MODE_BITSIZE (mode);
+    if (GET_MODE_PRECISION (*mode) == prec)
+      return GET_MODE_BITSIZE (*mode);
 
   gcc_unreachable ();
 }
@@ -1292,11 +1292,11 @@ fp_prec_to_size (int prec)
 int
 fp_size_to_prec (int size)
 {
-  machine_mode mode;
+  opt_scalar_float_mode mode;
 
   FOR_EACH_MODE_IN_CLASS (mode, MODE_FLOAT)
-    if (GET_MODE_BITSIZE (mode) == size)
-      return GET_MODE_PRECISION (mode);
+    if (GET_MODE_BITSIZE (*mode) == size)
+      return GET_MODE_PRECISION (*mode);
 
   gcc_unreachable ();
 }
diff --git a/gcc/c-family/c-cppbuiltin.c b/gcc/c-family/c-cppbuiltin.c
index 0d6f538..32a999a 100644
--- a/gcc/c-family/c-cppbuiltin.c
+++ b/gcc/c-family/c-cppbuiltin.c
@@ -1184,9 +1184,10 @@ c_cpp_builtins (cpp_reader *pfile)
   if (flag_building_libgcc)
     {
       /* Properties of floating-point modes for libgcc2.c.  */
-      machine_mode mode;
-      FOR_EACH_MODE_IN_CLASS (mode, MODE_FLOAT)
+      opt_scalar_float_mode mode_iter;
+      FOR_EACH_MODE_IN_CLASS (mode_iter, MODE_FLOAT)
 	{
+	  scalar_float_mode mode = *mode_iter;
 	  const char *name = GET_MODE_NAME (mode);
 	  char *macro_name
 	    = (char *) alloca (strlen (name)
diff --git a/gcc/expr.c b/gcc/expr.c
index a3a3e86..d277a88 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -110,7 +110,6 @@ void
 init_expr_target (void)
 {
   rtx pat;
-  machine_mode mode;
   int num_clobbers;
   rtx mem, mem1;
   rtx reg;
@@ -129,7 +128,7 @@ init_expr_target (void)
   pat = gen_rtx_SET (NULL_RTX, NULL_RTX);
   PATTERN (insn) = pat;
 
-  for (mode = VOIDmode; (int) mode < NUM_MACHINE_MODES;
+  for (machine_mode mode = VOIDmode; (int) mode < NUM_MACHINE_MODES;
        mode = (machine_mode_enum) ((int) mode + 1))
     {
       int regno;
@@ -175,9 +174,11 @@ init_expr_target (void)
 
   mem = gen_rtx_MEM (VOIDmode, gen_raw_REG (Pmode, LAST_VIRTUAL_REGISTER + 1));
 
-  FOR_EACH_MODE_IN_CLASS (mode, MODE_FLOAT)
+  opt_scalar_float_mode mode_iter;
+  FOR_EACH_MODE_IN_CLASS (mode_iter, MODE_FLOAT)
     {
-      machine_mode srcmode;
+      scalar_float_mode mode = *mode_iter;
+      scalar_float_mode srcmode;
       FOR_EACH_MODE_UNTIL (srcmode, mode)
 	{
 	  enum insn_code ic;
diff --git a/gcc/fortran/trans-types.c b/gcc/fortran/trans-types.c
index c0d1a17..4c69237 100644
--- a/gcc/fortran/trans-types.c
+++ b/gcc/fortran/trans-types.c
@@ -348,6 +348,7 @@ void
 gfc_init_kinds (void)
 {
   machine_mode_enum mode;
+  opt_scalar_float_mode float_mode_iter;
   int i_index, r_index, kind;
   bool saw_i4 = false, saw_i8 = false;
   bool saw_r4 = false, saw_r8 = false, saw_r10 = false, saw_r16 = false;
@@ -403,9 +404,10 @@ gfc_init_kinds (void)
   /* Set the maximum integer kind.  Used with at least BOZ constants.  */
   gfc_max_integer_kind = gfc_integer_kinds[i_index - 1].kind;
 
-  for (r_index = 0, mode = MIN_MODE_FLOAT; mode <= MAX_MODE_FLOAT;
-       mode = (machine_mode_enum) ((int) mode + 1))
+  r_index = 0;
+  FOR_EACH_MODE_IN_CLASS (float_mode_iter, MODE_FLOAT)
     {
+      scalar_float_mode mode = *float_mode_iter;
       const struct real_format *fmt = REAL_MODE_FORMAT (mode);
       int kind;
 
diff --git a/gcc/machmode.h b/gcc/machmode.h
index 41a3a00..2f4b076 100644
--- a/gcc/machmode.h
+++ b/gcc/machmode.h
@@ -628,6 +628,16 @@ namespace mode_iterator
 {
   /* Start mode iterator *ITER at the first mode in class MCLASS, if any.  */
 
+  template<typename T>
+  inline void
+  start (opt_mode<T> *iter, enum mode_class mclass)
+  {
+    if (GET_CLASS_NARROWEST_MODE (mclass) == E_VOIDmode)
+      *iter = opt_mode<T> ();
+    else
+      *iter = as_a<T> (GET_CLASS_NARROWEST_MODE (mclass));
+  }
+
   inline void
   start (machine_mode *iter, enum mode_class mclass)
   {
@@ -636,6 +646,13 @@ namespace mode_iterator
 
   /* Return true if mode iterator *ITER has not reached the end.  */
 
+  template<typename T>
+  inline bool
+  iterate_p (opt_mode<T> *iter)
+  {
+    return iter->exists ();
+  }
+
   inline bool
   iterate_p (machine_mode *iter)
   {
@@ -645,6 +662,13 @@ namespace mode_iterator
   /* Set mode iterator *ITER to the next widest mode in the same class,
      if any.  */
 
+  template<typename T>
+  inline void
+  get_wider (opt_mode<T> *iter)
+  {
+    *iter = GET_MODE_WIDER_MODE (**iter);
+  }
+
   inline void
   get_wider (machine_mode *iter)
   {
