1/*	$NetBSD: fpsetround.c,v 1.1 2006/07/01 16:37:20 ross Exp $	*/
2
3/*
4 * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Dan Winship.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34__RCSID("$NetBSD: fpsetround.c,v 1.1 2006/07/01 16:37:20 ross Exp $");
35#endif /* LIBC_SCCS and not lint */
36
37#include "namespace.h"
38
39#include <sys/types.h>
40#include <ieeefp.h>
41#include <powerpc/fpu.h>
42
43#ifdef __weak_alias
44__weak_alias(fpsetround,_fpsetround)
45#endif
46
47#define	ROUNDBITS	FPSCR_RN
48
49fp_rnd
50fpsetround(fp_rnd rnd_dir)
51{
52	uint64_t fpscr;
53	fp_rnd old;
54
55	__asm volatile("mffs %0" : "=f"(fpscr));
56	old = (uint32_t)fpscr & ROUNDBITS;
57	fpscr &= ~ROUNDBITS;
58	fpscr |= rnd_dir & ROUNDBITS;
59	__asm volatile("mtfsf 0xff,%0" :: "f"(fpscr));
60	return (old);
61}
62