xref: /freebsd/lib/libc/aarch64/gen/fpsetmask.c (revision d37eb51047221dc3322b34db1038ff3aa533883f)
1 /*-
2  * Copyright (c) 2015 The FreeBSD Foundation
3  *
4  * This software was developed by Andrew Turner under
5  * sponsorship from the FreeBSD Foundation.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/types.h>
30 #include <ieeefp.h>
31 
32 #define FP_X_MASK	(FP_X_INV | FP_X_DZ | FP_X_OFL | FP_X_UFL | FP_X_IMP)
33 
34 fp_except_t
35 fpsetmask(fp_except_t mask)
36 {
37 	uint64_t old, new;
38 
39 	mask &= FP_X_MASK;
40 
41 	/* Read the current mask */
42 	__asm __volatile("mrs %0, fpcr" : "=&r"(old));
43 	new = old & ~FP_X_MASK;
44 	new |= mask;
45 	__asm __volatile("msr fpcr, %0" :: "r"(new));
46 
47 	return ((fp_except_t)old);
48 }
49