/* ieee-utils/env.c

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough

 * 

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or (at

 * your option) any later version.

 * 

 * This program 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

 * General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

#include <config.h>

#include <stdlib.h>

#include <gsl/gsl_ieee_utils.h>

#include <gsl/gsl_errno.h>

void

gsl_ieee_env_setup (void)

{

  const char * p = getenv("GSL_IEEE_MODE") ;

  int precision = 0, rounding = 0, exception_mask = 0 ;

  int comma = 0 ;

#if defined( _MSC_VER )

    extern const char *fp_env_string;

	if(p == 0 || *p == '\0')

        p = fp_env_string;

#else

  if (p == 0)  /* GSL_IEEE_MODE environment variable is not set */

    return ;

  if (*p == '\0') /* GSL_IEEE_MODE environment variable is empty */

    return ;

#endif

  gsl_ieee_read_mode_string (p, &precision, &rounding, &exception_mask) ;

  gsl_ieee_set_mode (precision, rounding, exception_mask) ;

  fprintf(stderr, "GSL_IEEE_MODE=\"") ;

  /* Print string with a preceeding comma if the list has already begun */

#define PRINTC(x) do {if(comma) fprintf(stderr,","); fprintf(stderr,x); comma++ ;} while(0)

  switch (precision) 

    {

    case GSL_IEEE_SINGLE_PRECISION:

      PRINTC("single-precision") ;

      break ;

    case GSL_IEEE_DOUBLE_PRECISION:

      PRINTC("double-precision") ;

      break ;

    case GSL_IEEE_EXTENDED_PRECISION:

      PRINTC("extended-precision") ;

      break ;

    }

  switch (rounding) 

    {

    case GSL_IEEE_ROUND_TO_NEAREST:

      PRINTC("round-to-nearest") ;

      break ;

    case GSL_IEEE_ROUND_DOWN:

      PRINTC("round-down") ;

      break ;

    case GSL_IEEE_ROUND_UP:

      PRINTC("round-up") ;

      break ;

    case GSL_IEEE_ROUND_TO_ZERO:

      PRINTC("round-to-zero") ;

      break ;

    }

  if ((exception_mask & GSL_IEEE_MASK_ALL) == GSL_IEEE_MASK_ALL)

    {

      PRINTC("mask-all") ;

    }

  else if ((exception_mask & GSL_IEEE_MASK_ALL) == 0)

    {

      PRINTC("trap-common") ;

    }

  else 

    {

      if (exception_mask & GSL_IEEE_MASK_INVALID)

        PRINTC("mask-invalid") ;

      if (exception_mask & GSL_IEEE_MASK_DENORMALIZED)

        PRINTC("mask-denormalized") ;

      if (exception_mask & GSL_IEEE_MASK_DIVISION_BY_ZERO)

        PRINTC("mask-division-by-zero") ;

      if (exception_mask & GSL_IEEE_MASK_OVERFLOW)

        PRINTC("mask-overflow") ;

      if (exception_mask & GSL_IEEE_MASK_UNDERFLOW)

        PRINTC("mask-underflow") ;

    }

  if (exception_mask & GSL_IEEE_TRAP_INEXACT)

    PRINTC("trap-inexact") ;

  fprintf(stderr,"\"\n") ;

}