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/9699919799/functions/feupdateenv.html
40 *
41 * "The feupdateenv() function shall attempt to save the currently
42 * raised floating-point exceptions in its automatic storage, attempt
43 * to install the floating-point environment represented by the object
44 * pointed to by envp, and then attempt to raise the saved
45 * floating-point exceptions. The argument envp shall point to an
46 * object set by a call to feholdexcept() or fegetenv(), or equal a
47 * floating-point environment macro."
48 */
49
50 #if __riscv_flen
51
feupdateenv(const fenv_t * envp)52 int feupdateenv(const fenv_t *envp)
53 {
54
55 /* Get current exception flags */
56
57 fexcept_t flags;
58 __asm__ volatile("frflags %0" : "=r"(flags));
59
60 /* Set the environment as requested */
61
62 fenv_t fcsr = *envp; /* Environment to install */
63 __asm__ volatile("fscsr %0" : : "r"(fcsr)); /* Install environment */
64
65 /* OR in the saved exception flags */
66
67 __asm__ volatile("csrs fflags, %0" : : "r"(flags));
68
69 /* "The feupdateenv() function shall return a zero value if and only
70 * if all the required actions were successfully carried out."
71 */
72
73 return 0;
74
75 }
76 #else
77 #include "../../fenv/feupdateenv.c"
78 #endif
79
