blob: 966012d25c03c5aae0797d4f1f1cc2544810f00a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
/* Set the FPU control word for x86.
Copyright (C) 2003-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#include <fpu_control.h>
#include <fenv.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <dl-procinfo.h>
void
__setfpucw (fpu_control_t set)
{
fpu_control_t cw;
/* Fetch the current control word. */
__asm__ ("fnstcw %0" : "=m" (*&cw));
/* Preserve the reserved bits, and set the rest as the user
specified (or the default, if the user gave zero). */
cw &= _FPU_RESERVED;
cw |= set & ~_FPU_RESERVED;
__asm__ ("fldcw %0" : : "m" (*&cw));
/* If the CPU supports SSE, we set the MXCSR as well. */
if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
{
unsigned int xnew_exc;
/* Get the current MXCSR. */
__asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
xnew_exc &= ~((0xc00 << 3) | (FE_ALL_EXCEPT << 7));
xnew_exc |= ((set & 0xc00) << 3) | ((set & FE_ALL_EXCEPT) << 7);
__asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
}
}
|
