sysdeps/hppa/fpu/feholdexcpt.c

   1 /* Store current floating-point environment and clear exceptions.
   2    Copyright (C) 2000 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by David Huggins-Daines <dhd@debian.org>, 2000
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <fenv.h>
  22 #include <string.h>
  23
  24 int
  25 feholdexcept (fenv_t *envp)
  26 {
  27   union { unsigned long long buf[4]; fenv_t env; } clear;
  28   unsigned long long *bufptr;
  29
  30   /* Store the environment.  */
  31   bufptr = clear.buf;
  32   __asm__ (
  33            "fstd,ma %%fr0,8(%1)\n"
  34            : "=m" (clear), "+r" (bufptr) : : "%r0");
  35   memcpy (envp, &clear.env, sizeof (fenv_t));
  36
  37   /* Clear exception queues */
  38   memset (clear.env.__exception, 0, sizeof (clear.env.__exception));
  39   /* And set all exceptions to non-stop.  */
  40   clear.env.__status_word &= ~FE_ALL_EXCEPT;
  41   /* Now clear all flags  */
  42   clear.env.__status_word &= ~(FE_ALL_EXCEPT << 27);
  43
  44   /* Load the new environment. Note: fr0 must load last to enable T-bit
  45      Thus we start bufptr at the end and work backwards */
  46   bufptr = (unsigned int)(clear.buf) + sizeof(unsigned int)*4;
  47   __asm__ (
  48            "fldd,mb -8(%0),%%fr0\n"
  49            : : "r" (bufptr), "m" (clear) : "%r0");
  50
  51   return 0;
  52 }
  53
  54 libm_hidden_def (feholdexcept)
  55