xref: /openbsd-src/lib/libc/arch/alpha/gen/fpgetround.c (revision 29cc2a2d1d99869c4cfa9c708e043103e2d7d805)
1*29cc2a2dSguenther /*	$OpenBSD: fpgetround.c,v 1.5 2016/07/26 19:07:09 guenther Exp $	*/
28d0618b8Sniklas /*	$NetBSD: fpgetround.c,v 1.1 1995/04/29 05:09:55 cgd Exp $	*/
38d0618b8Sniklas 
4df930be7Sderaadt /*
5df930be7Sderaadt  * Copyright (c) 1995 Christopher G. Demetriou
6df930be7Sderaadt  * All rights reserved.
7df930be7Sderaadt  *
8df930be7Sderaadt  * Redistribution and use in source and binary forms, with or without
9df930be7Sderaadt  * modification, are permitted provided that the following conditions
10df930be7Sderaadt  * are met:
11df930be7Sderaadt  * 1. Redistributions of source code must retain the above copyright
12df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer.
13df930be7Sderaadt  * 2. Redistributions in binary form must reproduce the above copyright
14df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer in the
15df930be7Sderaadt  *    documentation and/or other materials provided with the distribution.
16df930be7Sderaadt  * 3. All advertising materials mentioning features or use of this software
17df930be7Sderaadt  *    must display the following acknowledgement:
18df930be7Sderaadt  *      This product includes software developed by Christopher G. Demetriou
19df930be7Sderaadt  *	for the NetBSD Project.
20df930be7Sderaadt  * 4. The name of the author may not be used to endorse or promote products
21df930be7Sderaadt  *    derived from this software without specific prior written permission
22df930be7Sderaadt  *
23df930be7Sderaadt  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24df930be7Sderaadt  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25df930be7Sderaadt  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26df930be7Sderaadt  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27df930be7Sderaadt  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28df930be7Sderaadt  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29df930be7Sderaadt  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30df930be7Sderaadt  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31df930be7Sderaadt  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32df930be7Sderaadt  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33df930be7Sderaadt  */
34df930be7Sderaadt 
35df930be7Sderaadt #include <sys/types.h>
36df930be7Sderaadt #include <ieeefp.h>
37df930be7Sderaadt 
38df930be7Sderaadt fp_rnd
fpgetround(void)39*29cc2a2dSguenther fpgetround(void)
40df930be7Sderaadt {
41df930be7Sderaadt 	double fpcrval;
42df930be7Sderaadt 	u_int64_t old;
43df930be7Sderaadt 
44df930be7Sderaadt 	__asm__("trapb");
45df930be7Sderaadt 	__asm__("mf_fpcr %0" : "=f" (fpcrval));
46df930be7Sderaadt 	__asm__("trapb");
47df930be7Sderaadt 	old = *(u_int64_t *)&fpcrval;
48df930be7Sderaadt 
49df930be7Sderaadt 	return ((old >> 58) & 0x3);
50df930be7Sderaadt }
51*29cc2a2dSguenther DEF_WEAK(fpgetround);
52