initial import of NetBSD tree

1 files changed, 65 insertions, 0 deletions

diff --git a/sys/lib/libkern/subdi3.c b/sys/lib/libkern/subdi3.c
new file mode 100644
index 00000000000..80350f9b8be
--- /dev/null
+++ b/sys/lib/libkern/subdi3.c
@@ -0,0 +1,65 @@
+/*	$NetBSD: subdi3.c,v 1.5 1995/10/07 09:26:52 mycroft Exp $	*/
+
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This software was developed by the Computer Systems Engineering group
+ * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
+ * contributed to Berkeley.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static char sccsid[] = "@(#)subdi3.c	8.1 (Berkeley) 6/4/93";
+#else
+static char rcsid[] = "$NetBSD: subdi3.c,v 1.5 1995/10/07 09:26:52 mycroft Exp $";
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+#include "quad.h"
+
+/*
+ * Subtract two quad values.  This is trivial since a one-bit carry
+ * from a single u_long difference x-y occurs if and only if (x-y) > x.
+ */
+quad_t
+__subdi3(a, b)
+	quad_t a, b;
+{
+	union uu aa, bb, diff;
+
+	aa.q = a;
+	bb.q = b;
+	diff.ul[L] = aa.ul[L] - bb.ul[L];
+	diff.ul[H] = aa.ul[H] - bb.ul[H] - (diff.ul[L] > aa.ul[L]);
+	return (diff.q);
+}