[patch] c-common.c: Stop using TREE_LIST for registered_builtin_types.

[Kazu Hirata]

Hi,

Attached is a patch to stop using TREE_LIST for
registered_builtin_types and use the VEC API instead.

Note that this patch does not change the order of the traversal in
c_common_type_for_mode because I traverse registered_builtin_types
backward.  I am not sure if that's important here though.

Tested on x86_64-pc-linux-gnu.  OK to apply to the LTO branch (and 4.3
once in Stage 1)?

Kazu Hirata

2006-06-02  Kazu Hirata  <kazu@codesourcery.com>

	* c-common.c (registered_builtin_types): Change the type to
	VEC(tree,gc) *.
	(c_common_type_for_mode, c_register_builtin_type): Update the
	uses of registered_builtin_types.

Index: c-common.c
===================================================================
--- c-common.c	(revision 114291)
+++ c-common.c	(working copy)
@@ -1640,7 +1640,7 @@ c_common_type_for_size (unsigned int bit
 
 /* Used for communication between c_common_type_for_mode and
    c_register_builtin_type.  */
-static GTY(()) tree registered_builtin_types;
+static GTY(()) VEC(tree,gc) *registered_builtin_types;
 
 /* Return a data type that has machine mode MODE.
    If the mode is an integer,
@@ -1650,6 +1650,7 @@ tree
 c_common_type_for_mode (enum machine_mode mode, int unsignedp)
 {
   tree t;
+  int i;
 
   if (mode == TYPE_MODE (integer_type_node))
     return unsignedp ? unsigned_type_node : integer_type_node;
@@ -1744,9 +1745,11 @@ c_common_type_for_mode (enum machine_mod
   if (mode == TYPE_MODE (dfloat128_type_node))
     return dfloat128_type_node;
 
-  for (t = registered_builtin_types; t; t = TREE_CHAIN (t))
-    if (TYPE_MODE (TREE_VALUE (t)) == mode)
-      return TREE_VALUE (t);
+  for (i = VEC_length (tree, registered_builtin_types);
+       VEC_iterate (tree, registered_builtin_types, i, t);
+       i--)
+    if (TYPE_MODE (t) == mode)
+      return t;
 
   return 0;
 }
@@ -1913,7 +1916,7 @@ c_register_builtin_type (tree type, cons
     TYPE_NAME (type) = decl;
   pushdecl (decl);
 
-  registered_builtin_types = tree_cons (0, type, registered_builtin_types);
+  VEC_safe_push (tree, gc, registered_builtin_types, type);
 }