sync with netbsd

1 files changed, 53 insertions, 0 deletions

diff --git a/lib/libc/arch/alpha/net/byte_swap_4.S b/lib/libc/arch/alpha/net/byte_swap_4.S
new file mode 100644
index 00000000000..37a53def822
--- /dev/null
+++ b/lib/libc/arch/alpha/net/byte_swap_4.S
@@ -0,0 +1,53 @@
+/*	$NetBSD: byte_swap_4.S,v 1.1 1996/04/17 22:36:49 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1996 Carnegie-Mellon University.
+ * All rights reserved.
+ *
+ * Author: Chris G. Demetriou
+ *
+ * Permission to use, copy, modify and distribute this software and
+ * its documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
+ * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie the
+ * rights to redistribute these changes.
+ */
+
+#include "DEFS.h"
+
+#ifndef NAME
+#define	NAME byte_swap_4
+#endif
+
+/*
+ * Byte-swap a 4-byte quantity.  (Convert 0x01234567 to 0x67452301.)
+ *
+ * Argument is an unsigned 4-byte integer (u_int32_t).
+ */
+LEAF(NAME, 1)			/* a0 contains 0x01234567 */
+	extbl	a0, 0, t0	/* t0 = 0x      67 */
+	extbl	a0, 1, t1	/* t1 = 0x      45 */
+	extbl	a0, 2, t2	/* t2 = 0x      23 */
+	extbl	a0, 3, t3	/* t3 = 0x      01 */
+	sll	t0, 24, t0	/* t0 = 0x67       */
+	sll	t1, 16, t1	/* t1 = 0x  45     */
+	sll	t2, 8, t2	/* t2 = 0x    23   */
+	or	t3, t0, v0	/* v0 = 0x67    01 */
+	or	t1, t2, t1	/* t1 = 0x  4523   */
+	or	t1, v0, v0	/* v0 = 0x67452301 */
+	RET
+END(NAME)