sysdeps/s390/fpu/fraiseexcpt.c

   1 /* Raise given exceptions.
   2    Copyright (C) 2000, 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Denis Joseph Barrow (djbarrow@de.ibm.com) and
   5    Martin Schwidefsky (schwidefsky@de.ibm.com).
   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_libc.h>
  23 #include <float.h>
  24 #include <math.h>
  25
  26
  27 static __inline__ void
  28 fexceptdiv (float d, float e)
  29 {
  30   __asm__ __volatile__ ("debr %0,%1" : : "f" (d), "f" (e) );
  31 }
  32
  33 static __inline__ void
  34 fexceptadd (float d, float e)
  35 {
  36   __asm__ __volatile__ ("aebr %0,%1" : : "f" (d), "f" (e) );
  37 }
  38
  39
  40 int
  41 feraiseexcept (int excepts)
  42 {
  43   /* Raise exceptions represented by EXPECTS.  But we must raise only
  44      one signal at a time.  It is important that if the overflow/underflow
  45      exception and the inexact exception are given at the same time,
  46      the overflow/underflow exception follows the inexact exception.  */
  47
  48   /* First: invalid exception.  */
  49   if (FE_INVALID & excepts)
  50     fexceptdiv (0.0, 0.0);
  51
  52   /* Next: division by zero.  */
  53   if (FE_DIVBYZERO & excepts)
  54     fexceptdiv (1.0, 0.0);
  55
  56   /* Next: overflow.  */
  57   if (FE_OVERFLOW & excepts)
  58     /* I don't think we can do the same trick as intel so we will have
  59        to live with inexact coming also.  */
  60     fexceptadd (FLT_MAX, 1.0e32);
  61
  62   /* Next: underflow.  */
  63   if (FE_UNDERFLOW & excepts)
  64     fexceptdiv (FLT_MIN, 3.0);
  65
  66   /* Last: inexact.  */
  67   if (FE_INEXACT & excepts)
  68     fexceptdiv (2.0, 3.0);
  69
  70   /* Success.  */
  71   return 0;
  72 }
  73 libm_hidden_def (feraiseexcept)