1 /* Store current floating-point environment and clear exceptions.
2 Copyright (C) 2000-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library. If not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <fenv.h>
20 #include <string.h>
21
22 int
__feholdexcept(fenv_t * envp)23 __feholdexcept (fenv_t *envp)
24 {
25 union { unsigned long long buf[4]; fenv_t env; } clear;
26 unsigned long long *bufptr;
27
28 /* Store the environment. */
29 bufptr = clear.buf;
30 __asm__ (
31 "fstd %%fr0,0(%1)\n"
32 : "=m" (clear) : "r" (bufptr) : "%r0");
33 memcpy (envp, &clear.env, sizeof (fenv_t));
34
35 /* Clear exception queues */
36 memset (clear.env.__exception, 0, sizeof (clear.env.__exception));
37 /* And set all exceptions to non-stop. */
38 clear.env.__status_word &= ~FE_ALL_EXCEPT;
39 /* Now clear all flags */
40 clear.env.__status_word &= ~(FE_ALL_EXCEPT << 27);
41
42 /* Load the new environment. Note: fr0 must load last to enable T-bit. */
43 __asm__ (
44 "fldd 0(%0),%%fr0\n"
45 : : "r" (bufptr), "m" (clear) : "%r0");
46
47 return 0;
48 }
49
50 libm_hidden_def (__feholdexcept)
51 weak_alias (__feholdexcept, feholdexcept)
52 libm_hidden_weak (feholdexcept)
53