1 /* Store current floating-point environment and clear exceptions.
2 Copyright (C) 1997, 1999, 2003, 2004, 2005, 2007
3 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
11
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
16
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <http://www.gnu.org/licenses/>. */
20
21 #include <fenv.h>
22 #include <unistd.h>
23
24 int
feholdexcept(fenv_t * envp)25 feholdexcept (fenv_t *envp)
26 {
27 fenv_t temp;
28
29 /* Store the environment. */
30 __asm__ ("fnstenv %0" : "=m" (temp));
31 *envp = temp;
32
33 /* Now set all exceptions to non-stop. */
34 temp.__control_word |= 0x3f;
35
36 /* And clear all exceptions. */
37 temp.__status_word &= ~0x3f;
38
39 __asm__ ("fldenv %0" : : "m" (temp));
40
41 #if 0
42 /* If the CPU supports SSE we set the MXCSR as well. */
43 if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
44 {
45 unsigned int xwork;
46
47 /* Get the current control word. */
48 __asm__ ("stmxcsr %0" : "=m" (*&xwork));
49
50 /* Set all exceptions to non-stop and clear them. */
51 xwork = (xwork | 0x1f80) & ~0x3f;
52
53 __asm__ ("ldmxcsr %0" : : "m" (*&xwork));
54 }
55 #endif
56
57 return 0;
58 }
59