1 files changed, 50 insertions, 0 deletions
diff --git a/libiberty/insque.c b/libiberty/insque.c
new file mode 100644
index 00000000000..775019f8fff
--- /dev/null
+++ b/libiberty/insque.c
@@ -0,0 +1,50 @@
+/* insque(3C) routines
+   This file is in the public domain.  */
+
+/*
+NAME
+	insque, remque -- insert, remove an element from a queue
+
+SYNOPSIS
+	struct qelem {
+	  struct qelem *q_forw;
+	  struct qelem *q_back;
+	  char q_data[];
+	};
+
+	void insque (struct qelem *elem, struct qelem *pred)
+
+	void remque (struct qelem *elem)
+
+DESCRIPTION
+	Routines to manipulate queues built from doubly linked lists.
+	The insque routine inserts ELEM in the queue immediately after
+	PRED.  The remque routine removes ELEM from its containing queue.
+*/
+
+
+struct qelem {
+  struct qelem *q_forw;
+  struct qelem *q_back;
+};
+
+
+void
+insque (elem, pred)
+  struct qelem *elem;
+  struct qelem *pred;
+{
+  elem -> q_forw = pred -> q_forw;
+  pred -> q_forw -> q_back = elem;
+  elem -> q_back = pred;
+  pred -> q_forw = elem;
+}
+
+
+void
+remque (elem)
+  struct qelem *elem;
+{
+  elem -> q_forw -> q_back = elem -> q_back;
+  elem -> q_back -> q_forw = elem -> q_forw;
+}