sysdeps/ia64/fpu/fraiseexcpt.c

   1 /* Raise given exceptions.
   2    Copyright (C) 1997, 1998, 2000, 2001, 2002, 2007
   3    Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5    Contributed by Jes Sorensen <Jes.Sorensen@cern.ch>, 2000.
   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 <float.h>
  24 #include <math.h>
  25 #include <signal.h>
  26 #include <unistd.h>
  27
  28 int
  29 feraiseexcept (int excepts)
  30 {
  31   double tmp;
  32   double dummy;
  33
  34   /* Raise exceptions represented by EXPECTS.  But we must raise only
  35      one signal at a time.  It is important the if the overflow/underflow
  36      exception and the inexact exception are given at the same time,
  37      the overflow/underflow exception precedes the inexact exception.  */
  38
  39   /* We do these bits in assembly to be certain GCC doesn't optimize
  40      away something important.  */
  41
  42   /* First: invalid exception.  */
  43   if (FE_INVALID & excepts)
  44     {
  45       /* One example of a invalid operation is 0 * Infinity.  */
  46       tmp = 0;
  47       __asm__ __volatile__ ("frcpa.s0 %0,p1=f0,f0" : "=f" (tmp) : : "p1" );
  48     }
  49
  50   /* Next: division by zero.  */
  51   if (FE_DIVBYZERO & excepts)
  52     __asm__ __volatile__ ("frcpa.s0 %0,p1=f1,f0" : "=f" (tmp) : : "p1" );
  53
  54   /* Next: overflow.  */
  55   if (FE_OVERFLOW & excepts)
  56     {
  57       dummy = DBL_MAX;
  58
  59       __asm__ __volatile__ ("fadd.d.s0 %0=%1,%1" : "=f" (dummy) : "0" (dummy));
  60     }
  61
  62   /* Next: underflow.  */
  63   if (FE_UNDERFLOW & excepts)
  64     {
  65       dummy = DBL_MIN;
  66
  67       __asm__ __volatile__ ("fnma.d.s0 %0=%1,%1,f0" : "=f" (tmp) : "f" (dummy));
  68   }
  69
  70   /* Last: inexact.  */
  71   if (FE_INEXACT & excepts)
  72     {
  73       dummy = DBL_MAX;
  74       __asm__ __volatile__ ("fsub.d.s0 %0=%1,f1" : "=f" (dummy) : "0" (dummy));
  75     }
  76
  77   /* Success.  */
  78   return 0;
  79 }
  80 libm_hidden_def (feraiseexcept)