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, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #include <fenv.h>
  22 #include <float.h>
  23 #include <math.h>
  24 #include <signal.h>
  25 #include <unistd.h>
  26
  27 int
  28 feraiseexcept (int excepts)
  29 {
  30   double tmp;
  31   double dummy;
  32
  33   /* Raise exceptions represented by EXPECTS.  But we must raise only
  34      one signal at a time.  It is important the if the overflow/underflow
  35      exception and the inexact exception are given at the same time,
  36      the overflow/underflow exception precedes the inexact exception.  */
  37
  38   /* We do these bits in assembly to be certain GCC doesn't optimize
  39      away something important.  */
  40
  41   /* First: invalid exception.  */
  42   if (FE_INVALID & excepts)
  43     {
  44       /* One example of a invalid operation is 0 * Infinity.  */
  45       tmp = 0;
  46       __asm__ __volatile__ ("frcpa.s0 %0,p1=f0,f0" : "=f" (tmp) : : "p1" );
  47     }
  48
  49   /* Next: division by zero.  */
  50   if (FE_DIVBYZERO & excepts)
  51     __asm__ __volatile__ ("frcpa.s0 %0,p1=f1,f0" : "=f" (tmp) : : "p1" );
  52
  53   /* Next: overflow.  */
  54   if (FE_OVERFLOW & excepts)
  55     {
  56       dummy = DBL_MAX;
  57
  58       __asm__ __volatile__ ("fadd.d.s0 %0=%1,%1" : "=f" (dummy) : "0" (dummy));
  59     }
  60
  61   /* Next: underflow.  */
  62   if (FE_UNDERFLOW & excepts)
  63     {
  64       dummy = DBL_MIN;
  65
  66       __asm__ __volatile__ ("fnma.d.s0 %0=%1,%1,f0" : "=f" (tmp) : "f" (dummy));
  67   }
  68
  69   /* Last: inexact.  */
  70   if (FE_INEXACT & excepts)
  71     {
  72       dummy = DBL_MAX;
  73       __asm__ __volatile__ ("fsub.d.s0 %0=%1,f1" : "=f" (dummy) : "0" (dummy));
  74     }
  75
  76   /* Success.  */
  77   return 0;
  78 }
  79 libm_hidden_def (feraiseexcept)