sysdeps/am33/fpu/fesetenv.c

   1 /* Install given floating-point environment.
   2    Copyright (C) 1998, 1999, 2000, 2002, 2004 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Alexandre Oliva <aoliva@redhat.com>
   5    based on corresponding file in the MIPS port.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library.  If not, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #include <fenv.h>
  22 #include <fpu_control.h>
  23 #include <shlib-compat.h>
  24
  25 int
  26 __fesetenv (const fenv_t *envp)
  27 {
  28   fpu_control_t cw;
  29
  30   /* We want to clear all EF bits for the default end IEEE.  */
  31
  32   if (envp == FE_DFL_ENV)
  33     _FPU_SETFCW (_FPU_DEFAULT|FE_ALL_EXCEPT);
  34   else if (envp == FE_NOMASK_ENV)
  35     _FPU_SETFCW (_FPU_IEEE|FE_ALL_EXCEPT);
  36   else
  37     {
  38       fpu_control_t temp;
  39
  40       _FPU_GETCW (temp);
  41       cw = *envp;
  42
  43       /* If EF bits are cleared and the user requests them to be set,
  44          we have to fail, because there's no way to do it.  */
  45       if (~temp & cw & FE_ALL_EXCEPT)
  46         return -1;
  47
  48       /* We clear EF bits by storing a 1 in them, so flip the
  49          FE_ALL_EXCEPT bits.  */
  50       cw = (cw & ~FE_ALL_EXCEPT) | (~cw & FE_ALL_EXCEPT);
  51       _FPU_SETFCW (cw);
  52     }
  53
  54   /* Success.  */
  55   return 0;
  56 }
  57
  58 libm_hidden_ver (__fesetenv, fesetenv)
  59 versioned_symbol (libm, __fesetenv, fesetenv, GLIBC_2_2);