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, write to the Free
  19    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  20    02111-1307 USA.  */
  21
  22 #include <fenv.h>
  23 #include <fpu_control.h>
  24 #include <shlib-compat.h>
  25
  26 int
  27 __fesetenv (const fenv_t *envp)
  28 {
  29   fpu_control_t cw;
  30
  31   /* We want to clear all EF bits for the default end IEEE.  */
  32
  33   if (envp == FE_DFL_ENV)
  34     _FPU_SETFCW (_FPU_DEFAULT|FE_ALL_EXCEPT);
  35   else if (envp == FE_NOMASK_ENV)
  36     _FPU_SETFCW (_FPU_IEEE|FE_ALL_EXCEPT);
  37   else
  38     {
  39       fpu_control_t temp;
  40
  41       _FPU_GETCW (temp);
  42       cw = *envp;
  43
  44       /* If EF bits are cleared and the user requests them to be set,
  45          we have to fail, because there's no way to do it.  */
  46       if (~temp & cw & FE_ALL_EXCEPT)
  47         return -1;
  48
  49       /* We clear EF bits by storing a 1 in them, so flip the
  50          FE_ALL_EXCEPT bits.  */
  51       cw = (cw & ~FE_ALL_EXCEPT) | (~cw & FE_ALL_EXCEPT);
  52       _FPU_SETFCW (cw);
  53     }
  54
  55   /* Success.  */
  56   return 0;
  57 }
  58
  59 libm_hidden_ver (__fesetenv, fesetenv)
  60 versioned_symbol (libm, __fesetenv, fesetenv, GLIBC_2_2);