1 /*
2   (c) Copyright 2017 Michael R. Neilly
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 
9   * Redistributions of source code must retain the above copyright
10   notice, this list of conditions and the following disclaimer.
11 
12   * Redistributions in binary form must reproduce the above copyright
13   notice, this list of conditions and the following disclaimer in the
14   documentation and/or other materials provided with the distribution.
15 
16   * Neither the names of the copyright holders nor the names of their
17   contributors may be used to endorse or promote products derived from
18   this software without specific prior written permission.
19 
20   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24   COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26   BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
28   CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
30   ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31   POSSIBILITY OF SUCH DAMAGE.
32 */
33 
34 #include <fenv.h>
35 
36 /* This implementation is intended to comply with the following
37  * specification:
38  *
39  * http://pubs.opengroup.org/onlinepubs/009695399/functions/fesetround.html
40  * Referred to as 'fegetenv.html below.
41  *
42  * "The fesetround() function shall establish the rounding direction
43  * represented by its argument round. If the argument is not equal to
44  * the value of a rounding direction macro, the rounding direction is
45  * not changed."
46  */
47 
48 #if __riscv_flen
49 
fesetround(int round)50 int fesetround(int round)
51 {
52 
53   /* Mask round to be sure only valid rounding bits are set */
54 
55   round &= FE_RMODE_MASK;
56 
57   /* Set the rounding mode */
58 
59   __asm__ volatile("fsrm %0" : : "r"(round));
60 
61   /* Per 'fesetround.html:
62    *
63    * "The fesetround() function shall return a zero value if and only
64    * if the requested rounding direction was established."
65    */
66 
67   return 0;
68 }
69 #else
70 #include ".././fenv/fesetround.c"
71 #endif
72