+void xbt_swag_insert_at_head(void *obj, xbt_swag_t swag)
+{
+
+ if (xbt_swag_belongs(obj, swag))
+ return;
+
+ (swag->count)++;
+ if (swag->head == NULL) {
+ swag->head = obj;
+ swag->tail = obj;
+ return;
+ }
+
+ NEXT(obj, swag->offset) = swag->head;
+ PREV(NEXT(obj, swag->offset), swag->offset) = obj;
+
+ swag->head = obj;
+}
+
+void xbt_swag_insert_at_tail(void *obj, xbt_swag_t swag)
+{
+
+ if (xbt_swag_belongs(obj, swag))
+ return;
+
+ (swag->count)++;
+ if (swag->head == NULL) {
+ swag->head = obj;
+ swag->tail = obj;
+ return;
+ }
+
+ PREV(obj, swag->offset) = swag->tail;
+ NEXT(PREV(obj, swag->offset), swag->offset) = obj;
+
+ swag->tail = obj;
+}
+