1 /* Set current rounding direction.
2 Copyright (C) 2001, 2005 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 fesetround (int round
)
25 unsigned short int cw
;
28 if ((round
& ~0xc00) != 0)
29 /* ROUND is no valid rounding mode. */
32 /* First set the x87 FPU. */
33 asm ("fnstcw %0" : "=m" (*&cw
));
36 asm ("fldcw %0" : : "m" (*&cw
));
38 /* And now the MSCSR register for SSE, the precision is at different bit
39 positions in the different units, we need to shift it 3 bits. */
40 asm ("stmxcsr %0" : "=m" (*&mxcsr
));
43 asm ("ldmxcsr %0" : : "m" (*&mxcsr
));
47 libm_hidden_def (fesetround
)