1 /*-
2 * Copyright (c) 2015 The NetBSD Foundation, Inc.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to The NetBSD Foundation
6 * by Matt Thomas of 3am Software Foundry.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31
32 __RCSID("$NetBSD: fpsetround.c,v 1.1 2015/07/07 21:40:19 matt Exp $");
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bitops.h>
37
38 #include "namespace.h"
39
40 #include <ieeefp.h>
41
42 #include <aarch64/armreg.h>
43
44 __weak_alias(fpsetround,_fpsetround);
45
46 fp_rnd_t
fpsetround(fp_rnd_t rnd)47 fpsetround(fp_rnd_t rnd)
48 {
49 const uint32_t old_fpcr = reg_fpcr_read();
50 const uint32_t new_fpcr = (~old_fpcr & ~FPCR_RMODE)
51 | __SHIFTIN(rnd, FPCR_RMODE);
52 reg_fpcr_write(new_fpcr);
53 return __SHIFTOUT(old_fpcr, FPCR_RMODE);
54 }
55