ports/sysdeps/hppa/fpu/feholdexcpt.c

   1 /* Store current floating-point environment and clear exceptions.
   2    Copyright (C) 2000-2014 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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <fenv.h>
  21 #include <string.h>
  22
  23 int
  24 feholdexcept (fenv_t *envp)
  25 {
  26   union { unsigned long long buf[4]; fenv_t env; } clear;
  27   unsigned long long *bufptr;
  28
  29   /* Store the environment.  */
  30   bufptr = clear.buf;
  31   __asm__ (
  32            "fstd,ma %%fr0,8(%1)\n"
  33            : "=m" (clear), "+r" (bufptr) : : "%r0");
  34   memcpy (envp, &clear.env, sizeof (fenv_t));
  35
  36   /* Clear exception queues */
  37   memset (clear.env.__exception, 0, sizeof (clear.env.__exception));
  38   /* And set all exceptions to non-stop.  */
  39   clear.env.__status_word &= ~FE_ALL_EXCEPT;
  40   /* Now clear all flags  */
  41   clear.env.__status_word &= ~(FE_ALL_EXCEPT << 27);
  42
  43   /* Load the new environment. Note: fr0 must load last to enable T-bit
  44      Thus we start bufptr at the end and work backwards */
  45   bufptr = (unsigned long long *)((unsigned int)(clear.buf) + sizeof(unsigned int)*4);
  46   __asm__ (
  47            "fldd,mb -8(%0),%%fr0\n"
  48            : : "r" (bufptr), "m" (clear) : "%r0");
  49
  50   return 0;
  51 }
  52
  53 libm_hidden_def (feholdexcept)
  54