1 /*
2 * Copyright (C) 2001-2016 Free Software Foundation, Inc.
3 * Contributed by David S. Miller (davem@redhat.com)
4 *
5 * This file is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 3, or (at your option) any
8 * later version.
9 *
10 * This file is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * Under Section 7 of GPL version 3, you are granted additional
16 * permissions described in the GCC Runtime Library Exception, version
17 * 3.1, as published by the Free Software Foundation.
18 *
19 * You should have received a copy of the GNU General Public License and
20 * a copy of the GCC Runtime Library Exception along with this program;
21 * see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
22 * <http://www.gnu.org/licenses/>.
23 */
24
25 #define FPRS_NS (1 << 22) /* Non-Standard fpu results */
26
27 static void __attribute__((constructor))
set_fast_math(void)28 set_fast_math (void)
29 {
30 unsigned int fsr;
31
32 /* This works for the 64-bit case because, even if 32-bit ld/st of
33 the fsr register modified the upper 32-bit, the only thing up there
34 are the 3 other condition codes which are "do not care" at the time
35 that this runs. */
36
37 __asm__("st %%fsr, %0"
38 : "=m" (fsr));
39
40 fsr |= FPRS_NS;
41
42 __asm__("ld %0, %%fsr"
43 : : "m" (fsr));
44 }
45