xref: /freebsd/lib/libc/arm/gen/flt_rounds.c (revision ddd5b8e9b4d8957fce018c520657cdfa4ecffad3)
1 /*-
2  * Copyright (c) 2012 Ian Lepore <freebsd@damnhippie.dyndns.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <fenv.h>
31 #include <float.h>
32 
33 #include "softfloat-for-gcc.h"
34 #include "milieu.h"
35 #include "softfloat.h"
36 
37 int
38 __flt_rounds(void)
39 {
40 
41 #ifndef ARM_HARD_FLOAT
42 	/*
43 	 * Translate our rounding modes to the unnamed
44 	 * manifest constants required by C99 et. al.
45 	 */
46 	switch (__softfloat_float_rounding_mode) {
47 	case FE_TOWARDZERO:
48 		return (0);
49 	case FE_TONEAREST:
50 		return (1);
51 	case FE_UPWARD:
52 		return (2);
53 	case FE_DOWNWARD:
54 		return (3);
55 	}
56 	return (-1);
57 #else /* ARM_HARD_FLOAT */
58 	/*
59 	 * Apparently, the rounding mode is specified as part of the
60 	 * instruction format on ARM, so the dynamic rounding mode is
61 	 * indeterminate.  Some FPUs may differ.
62 	 */
63 	return (-1);
64 #endif /* ARM_HARD_FLOAT */
65 }
66