sysdeps/s390/fpu/fraiseexcpt.c

   1 /* Raise given exceptions.
   2    Copyright (C) 2000-2014 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, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #include <fenv_libc.h>
  22 #include <float.h>
  23 #include <math.h>
  24
  25
  26 static __inline__ void
  27 fexceptdiv (float d, float e)
  28 {
  29   __asm__ __volatile__ ("debr %0,%1" : : "f" (d), "f" (e) );
  30 }
  31
  32 static __inline__ void
  33 fexceptadd (float d, float e)
  34 {
  35   __asm__ __volatile__ ("aebr %0,%1" : : "f" (d), "f" (e) );
  36 }
  37
  38
  39 int
  40 feraiseexcept (int excepts)
  41 {
  42   /* Raise exceptions represented by EXPECTS.  But we must raise only
  43      one signal at a time.  It is important that if the overflow/underflow
  44      exception and the inexact exception are given at the same time,
  45      the overflow/underflow exception follows the inexact exception.  */
  46
  47   /* First: invalid exception.  */
  48   if (FE_INVALID & excepts)
  49     fexceptdiv (0.0, 0.0);
  50
  51   /* Next: division by zero.  */
  52   if (FE_DIVBYZERO & excepts)
  53     fexceptdiv (1.0, 0.0);
  54
  55   /* Next: overflow.  */
  56   if (FE_OVERFLOW & excepts)
  57     /* I don't think we can do the same trick as intel so we will have
  58        to live with inexact coming also.  */
  59     fexceptadd (FLT_MAX, 1.0e32);
  60
  61   /* Next: underflow.  */
  62   if (FE_UNDERFLOW & excepts)
  63     fexceptdiv (FLT_MIN, 3.0);
  64
  65   /* Last: inexact.  */
  66   if (FE_INEXACT & excepts)
  67     fexceptdiv (2.0, 3.0);
  68
  69   /* Success.  */
  70   return 0;
  71 }
  72 libm_hidden_def (feraiseexcept)