sysdeps/alpha/fpu/fesetmode.c

   1 /* Install given floating-point control modes.  Alpha version.
   2    Copyright (C) 2016 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <fenv_libc.h>
  20
  21 int
  22 fesetmode (const femode_t *modep)
  23 {
  24   unsigned long int fpcr;
  25   unsigned long int swcr;
  26   femode_t mode;
  27
  28   /* As in fesetenv.  */
  29   if ((long int) modep >= 0)
  30     mode = *modep;
  31   else
  32     mode = (unsigned long int) modep;
  33
  34   __asm__ __volatile__ ("excb; mf_fpcr %0" : "=f" (fpcr));
  35   fpcr = (fpcr & ~FPCR_ROUND_MASK) | (mode & FPCR_ROUND_MASK);
  36   __asm__ __volatile__ ("mt_fpcr %0" : : "f" (fpcr));
  37
  38   swcr = __ieee_get_fp_control ();
  39   swcr = ((mode & SWCR_ALL_MASK & ~SWCR_STATUS_MASK)
  40           | (swcr & SWCR_STATUS_MASK));
  41   __ieee_set_fp_control (swcr);
  42
  43   return 0;
  44 }