xref: /minix3/lib/libc/arch/arm/hardfloat/fpgetround.c (revision 2fe8fb192fe7e8720e3e7a77f928da545e872a6a)
1*2fe8fb19SBen Gras /*	$NetBSD: fpgetround.c,v 1.4 2006/02/25 02:28:55 wiz Exp $	*/
2*2fe8fb19SBen Gras 
3*2fe8fb19SBen Gras /*
4*2fe8fb19SBen Gras  * Copyright (c) 1996 Mark Brinicombe
5*2fe8fb19SBen Gras  * All rights reserved.
6*2fe8fb19SBen Gras  *
7*2fe8fb19SBen Gras  * Redistribution and use in source and binary forms, with or without
8*2fe8fb19SBen Gras  * modification, are permitted provided that the following conditions
9*2fe8fb19SBen Gras  * are met:
10*2fe8fb19SBen Gras  * 1. Redistributions of source code must retain the above copyright
11*2fe8fb19SBen Gras  *    notice, this list of conditions and the following disclaimer.
12*2fe8fb19SBen Gras  * 2. Redistributions in binary form must reproduce the above copyright
13*2fe8fb19SBen Gras  *    notice, this list of conditions and the following disclaimer in the
14*2fe8fb19SBen Gras  *    documentation and/or other materials provided with the distribution.
15*2fe8fb19SBen Gras  * 3. All advertising materials mentioning features or use of this software
16*2fe8fb19SBen Gras  *    must display the following acknowledgement:
17*2fe8fb19SBen Gras  *      This product includes software developed by Mark Brinicombe
18*2fe8fb19SBen Gras  *	for the NetBSD Project.
19*2fe8fb19SBen Gras  * 4. The name of the author may not be used to endorse or promote products
20*2fe8fb19SBen Gras  *    derived from this software without specific prior written permission
21*2fe8fb19SBen Gras  *
22*2fe8fb19SBen Gras  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23*2fe8fb19SBen Gras  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24*2fe8fb19SBen Gras  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25*2fe8fb19SBen Gras  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26*2fe8fb19SBen Gras  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27*2fe8fb19SBen Gras  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28*2fe8fb19SBen Gras  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29*2fe8fb19SBen Gras  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30*2fe8fb19SBen Gras  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31*2fe8fb19SBen Gras  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32*2fe8fb19SBen Gras  */
33*2fe8fb19SBen Gras 
34*2fe8fb19SBen Gras #include <sys/cdefs.h>
35*2fe8fb19SBen Gras #if defined(LIBC_SCCS) && !defined(lint)
36*2fe8fb19SBen Gras __RCSID("$NetBSD: fpgetround.c,v 1.4 2006/02/25 02:28:55 wiz Exp $");
37*2fe8fb19SBen Gras #endif /* LIBC_SCCS and not lint */
38*2fe8fb19SBen Gras 
39*2fe8fb19SBen Gras #include "namespace.h"
40*2fe8fb19SBen Gras 
41*2fe8fb19SBen Gras #include <sys/types.h>
42*2fe8fb19SBen Gras #include <ieeefp.h>
43*2fe8fb19SBen Gras 
44*2fe8fb19SBen Gras #ifdef __weak_alias
45*2fe8fb19SBen Gras __weak_alias(fpgetround,_fpgetround)
46*2fe8fb19SBen Gras #endif
47*2fe8fb19SBen Gras 
48*2fe8fb19SBen Gras /*
49*2fe8fb19SBen Gras  * Return the current FP rounding mode
50*2fe8fb19SBen Gras  *
51*2fe8fb19SBen Gras  * ok all we need to do is return the current FP rounding mode
52*2fe8fb19SBen Gras  *
53*2fe8fb19SBen Gras  * HOWEVER:
54*2fe8fb19SBen Gras  * The ARM FPA codes the rounding mode into the actual FP instructions
55*2fe8fb19SBen Gras  * so there is no such thing as a global rounding mode.
56*2fe8fb19SBen Gras  * The default is round to nearest if rounding is not explicitly specified.
57*2fe8fb19SBen Gras  * FP instructions generated by GCC will not explicitly specify a rounding
58*2fe8fb19SBen Gras  * mode.
59*2fe8fb19SBen Gras  *
60*2fe8fb19SBen Gras  * So the best we can do it to return the rounding mode FP instructions
61*2fe8fb19SBen Gras  * use if rounding is not specified which is round to nearest.
62*2fe8fb19SBen Gras  *
63*2fe8fb19SBen Gras  * This could change in the future with new floating point emulators or
64*2fe8fb19SBen Gras  * soft float FP libraries.
65*2fe8fb19SBen Gras  */
66*2fe8fb19SBen Gras 
67*2fe8fb19SBen Gras fp_rnd
68*2fe8fb19SBen Gras fpgetround()
69*2fe8fb19SBen Gras {
70*2fe8fb19SBen Gras 
71*2fe8fb19SBen Gras 	return(FP_RN);
72*2fe8fb19SBen Gras }
73