1 /* Set floating-point environment exception handling.
2    Copyright (C) 2000-2022 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_libc.h>
20 #include <math.h>
21 #include <fpu_control.h>
22 
23 int
fesetexceptflag(const fexcept_t * flagp,int excepts)24 fesetexceptflag (const fexcept_t *flagp, int excepts)
25 {
26   fexcept_t fpc, fpc_new;
27 
28   /* Get the current environment.  We have to do this since we cannot
29      separately set the status word.  */
30   _FPU_GETCW (fpc);
31 
32   /* Clear the current exception bits.  */
33   fpc_new = fpc & ~((excepts & FE_ALL_EXCEPT) << FPC_FLAGS_SHIFT);
34   if ((fpc & FPC_NOT_FPU_EXCEPTION) == 0)
35     /* Bits 6, 7 of dxc-byte are zero,
36        thus bits 0-5 of dxc-byte correspond to the flag-bits.
37        Clear given exceptions in dxc-field.  */
38     fpc_new &= ~((excepts & FE_ALL_EXCEPT) << FPC_DXC_SHIFT);
39 
40   /* Set exceptions from flagp in flags-field.  */
41   fpc_new |= (*flagp & excepts & FE_ALL_EXCEPT) << FPC_FLAGS_SHIFT;
42 
43   /* Store the new status word (along with the rest of the environment.
44      Possibly new exceptions are set but they won't get executed.  */
45   _FPU_SETCW (fpc_new);
46 
47   /* Success.  */
48   return 0;
49 }
50