xref: /minix/lib/libc/arch/powerpc/gen/fpgetround.c (revision e415d488)
1 /*	$NetBSD: fpgetround.c,v 1.10 2011/07/10 21:18:47 matt 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: fpgetround.c,v 1.10 2011/07/10 21:18:47 matt 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
__weak_alias(fpgetround,_fpgetround)44 __weak_alias(fpgetround,_fpgetround)
45 #endif
46 
47 #define	ROUNDBITS	FPSCR_RN
48 #define	ROUNDSHFT	0
49 
50 fp_rnd
51 fpgetround(void)
52 {
53 	union {
54 		double u_d;
55 		uint64_t u_fpscr;
56 	} ud;
57 
58 	__asm volatile("mffs %0" : "=f"(ud.u_d));
59 	return (((uint32_t)ud.u_fpscr & ROUNDBITS) >> ROUNDSHFT);
60 }
61