1/* Return current rounding direction.
2 Copyright (C) 1997-2022 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
21int
22__fegetround (void)
23{
24 int cw;
25 /* We only check the x87 FPU unit. The SSE unit should be the same
26 - and if it's not the same there's no way to signal it. */
27
28 __asm__ ("fnstcw %0" : "=m" (*&cw));
29
30 return cw & 0xc00;
31}
32libm_hidden_def (__fegetround)
33weak_alias (__fegetround, fegetround)
34libm_hidden_weak (fegetround)
35

source code of glibc/sysdeps/x86_64/fpu/fegetround.c