1 /* $OpenBSD: flt_rounds.c,v 1.1 2020/06/25 02:03:55 drahn Exp $ */
2 /* $NetBSD: flt_rounds.c,v 1.5 2001/05/25 12:14:05 simonb Exp $ */
3
4 /*
5 * Copyright (c) 1996 Mark Brinicombe
6 * All rights reserved.
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 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by Mark Brinicombe
19 * for the NetBSD Project.
20 * 4. The name of the author may not be used to endorse or promote products
21 * derived from this software without specific prior written permission
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 #include <sys/types.h>
36 #include <float.h>
37 #include <ieeefp.h>
38
39
40 static const int map[] = {
41 1, /* round to nearest */
42 0, /* round to zero */
43 2, /* round to positive infinity */
44 3 /* round to negative infinity */
45 };
46
47 int
__flt_rounds(void)48 __flt_rounds(void)
49 {
50 #ifdef _SOFT_FLOAT
51 return map[fpgetround()];
52 #else
53 double tmp;
54 int x;
55
56 __asm__ volatile("mffs %0; stfiwx %0,0,%1" : "=f"(tmp): "b"(&x));
57 return map[x & 0x03];
58 #endif
59 }
60 DEF_STRONG(__flt_rounds);
61