[5/67] Small tweak to array_value_type

[Richard Sandiford]

Store the type mode in a variable so that a later,
more mechanical patch can change its type.

gcc/
2016-11-24  Richard Sandiford  <richard.sandif...@arm.com>
            Alan Hayward  <alan.hayw...@arm.com>
            David Sherwood  <david.sherw...@arm.com>

        * tree-switch-conversion.c (array_value_type): Only read TYPE_MODE
        once.  Use get_narrowest_mode instead of GET_CLASS_NARROWEST_MODE.

diff --git a/gcc/tree-switch-conversion.c b/gcc/tree-switch-conversion.c
index b063c46..8b64f4b 100644
--- a/gcc/tree-switch-conversion.c
+++ b/gcc/tree-switch-conversion.c
@@ -945,15 +945,15 @@ array_value_type (gswitch *swtch, tree type, int num,
 {
   unsigned int i, len = vec_safe_length (info->constructors[num]);
   constructor_elt *elt;
-  machine_mode mode;
   int sign = 0;
   tree smaller_type;
 
   if (!INTEGRAL_TYPE_P (type))
     return type;
 
-  mode = GET_CLASS_NARROWEST_MODE (GET_MODE_CLASS (TYPE_MODE (type)));
-  if (GET_MODE_SIZE (TYPE_MODE (type)) <= GET_MODE_SIZE (mode))
+  machine_mode type_mode = TYPE_MODE (type);
+  machine_mode mode = get_narrowest_mode (type_mode);
+  if (GET_MODE_SIZE (type_mode) <= GET_MODE_SIZE (mode))
     return type;
 
   if (len < (optimize_bb_for_size_p (gimple_bb (swtch)) ? 2 : 32))
@@ -991,7 +991,7 @@ array_value_type (gswitch *swtch, tree type, int num,
 
          mode = GET_MODE_WIDER_MODE (mode);
          if (mode == VOIDmode
-             || GET_MODE_SIZE (mode) >= GET_MODE_SIZE (TYPE_MODE (type)))
+             || GET_MODE_SIZE (mode) >= GET_MODE_SIZE (type_mode))
            return type;
        }
     }