/* Raise given exceptions.   Copyright (C) 2001, 2002 Free Software Foundation, Inc.   This file is part of the GNU C Library.   The GNU C Library is free software; you can redistribute it and/or   modify it under the terms of the GNU Lesser General Public   License as published by the Free Software Foundation; either   version 2.1 of the License, or (at your option) any later version.   The GNU C Library is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU   Lesser General Public License for more details.   You should have received a copy of the GNU Lesser General Public   License along with the GNU C Library; if not, write to the Free   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA   02111-1307 USA.  */#include <fenv.h>#include <math.h>intferaiseexcept (int excepts){  /* Raise exceptions represented by EXPECTS.  But we must raise only     one signal at a time.  It is important that if the overflow/underflow     exception and the inexact exception are given at the same time,     the overflow/underflow exception follows the inexact exception.  */  /* First: invalid exception.  */  if ((FE_INVALID & excepts) != 0)    {      /* One example of a invalid operation is 0.0 / 0.0.  */      float f = 0.0;      __asm__ __volatile__ ("divss %0, %0 " : : "x" (f));      (void) &f;    }  /* Next: division by zero.  */  if ((FE_DIVBYZERO & excepts) != 0)    {      float f = 1.0;      float g = 0.0;      __asm__ __volatile__ ("divss %1, %0" : : "x" (f), "x" (g));      (void) &f;    }  /* Next: overflow.  */  if ((FE_OVERFLOW & excepts) != 0)    {      /* XXX: Is it ok to only set the x87 FPU?  */      /* There is no way to raise only the overflow flag.  Do it the	 hard way.  */      fenv_t temp;      /* Bah, we have to clear selected exceptions.  Since there is no	 `fldsw' instruction we have to do it the hard way.  */      __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp));      /* Set the relevant bits.  */      temp.__status_word |= FE_OVERFLOW;      /* Put the new data in effect.  */      __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp));      /* And raise the exception.  */      __asm__ __volatile__ ("fwait");    }  /* Next: underflow.  */  if ((FE_UNDERFLOW & excepts) != 0)    {      /* XXX: Is it ok to only set the x87 FPU?  */      /* There is no way to raise only the underflow flag.  Do it the	 hard way.  */      fenv_t temp;      /* Bah, we have to clear selected exceptions.  Since there is no	 `fldsw' instruction we have to do it the hard way.  */      __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp));      /* Set the relevant bits.  */      temp.__status_word |= FE_UNDERFLOW;      /* Put the new data in effect.  */      __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp));      /* And raise the exception.  */      __asm__ __volatile__ ("fwait");    }  /* Last: inexact.  */  if ((FE_INEXACT & excepts) != 0)    {      /* XXX: Is it ok to only set the x87 FPU?  */      /* There is no way to raise only the inexact flag.  Do it the	 hard way.  */      fenv_t temp;      /* Bah, we have to clear selected exceptions.  Since there is no	 `fldsw' instruction we have to do it the hard way.  */      __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp));      /* Set the relevant bits.  */      temp.__status_word |= FE_INEXACT;      /* Put the new data in effect.  */      __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp));      /* And raise the exception.  */      __asm__ __volatile__ ("fwait");    }  /* Success.  */  return 0;}libm_hidden_def (feraiseexcept)