sysdeps/am33/fpu/fsetexcptflg.c

   1 /* Set floating-point environment exception handling.
   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 __fesetexceptflag (const fexcept_t *flagp, int excepts)
  28 {
  29   fpu_control_t cw, temp;
  30
  31   /* Get the current exceptions.  */
  32   _FPU_GETCW (cw);
  33
  34   /* Make sure the flags we want restored are legal.  */
  35   excepts &= FE_ALL_EXCEPT;
  36   temp = *flagp & excepts;
  37
  38   /* If EF bits are clear and the user requests them to be set,
  39      we have to fail, because there's no way to do it.  */
  40   if (~(cw & excepts) & temp)
  41     return -1;
  42
  43   /* We clear EF bits by storing a 1 in them, so flip the
  44      FE_ALL_EXCEPT bits.  */
  45   temp = (~temp & FE_ALL_EXCEPT);
  46
  47   /* Now clear the bits called for, and copy them in from flagp. Note that
  48      we ignore all non-flag bits from *flagp, so they don't matter.  */
  49   cw = (cw & ~FE_ALL_EXCEPT) | temp;
  50
  51   _FPU_SETFCW (cw);
  52
  53   /* Success.  */
  54   return 0;
  55 }
  56
  57 versioned_symbol (libm, __fesetexceptflag, fesetexceptflag, GLIBC_2_2);