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New ieee-utils/fp-netbsd.c file



Here is some FP exception support for NetBSD systems.

FP_X_DNML is only available on i386 and sh3 ports.  Of course, the VAX
doesn't support IEEE arithmetic at all -- I don't know what we can do
for it :-)

Note that the string MACHINE, ("luna68k", "alpha", ...), is defined in
<sys/param.h>.  You might like to change that part.

Feel free to include it in GSL.

Regards,

Jason Beegan.

aka jtb@netbsd.org


#include <ieeefp.h>
#include <sys/param.h>
#include <gsl/gsl_ieee_utils.h>
#include <gsl/gsl_errno.h>

int
gsl_ieee_set_mode (int precision, int rounding, int exception_mask)
{
  fp_except mode = 0;
  fp_rnd    rnd  = 0;

  switch (precision)
    {
    case GSL_IEEE_SINGLE_PRECISION:
      GSL_ERROR ("NetBSD only supports default precision rounding",
		 GSL_EUNSUP);
      break;
    case GSL_IEEE_DOUBLE_PRECISION:
      GSL_ERROR ("NetBSD only supports default precision rounding",
		 GSL_EUNSUP);
      break;
    case GSL_IEEE_EXTENDED_PRECISION:
      GSL_ERROR ("NetBSD only supports default precision rounding",
		 GSL_EUNSUP);
      break;
    }

  switch (rounding)
    {
    case GSL_IEEE_ROUND_TO_NEAREST:
      rnd = FP_RN;
      fpsetround (rnd);
      break;
    case GSL_IEEE_ROUND_DOWN:
      rnd = FP_RM;
      fpsetround (rnd);
      break;
    case GSL_IEEE_ROUND_UP:
      rnd = FP_RP;
      fpsetround (rnd);
      break;
    case GSL_IEEE_ROUND_TO_ZERO:
      rnd = FP_RZ;
      fpsetround (rnd);
      break;
    default:
      rnd = FP_RN;
      fpsetround (rnd);
    }

/* Turn on all available exceptions apart from 'inexact'.
   Denormalized operand exception not available on all ports. */

#ifdef FP_X_DNML
  mode = FP_X_INV | FP_X_DNML | FP_X_DZ | FP_X_OFL | FP_X_UFL;
#else
  mode = FP_X_INV | FP_X_DZ | FP_X_OFL | FP_X_UFL;
#endif

  if (exception_mask & GSL_IEEE_MASK_INVALID)
    mode &= ~ FP_X_INV;

  if (exception_mask & GSL_IEEE_MASK_DENORMALIZED)
#ifdef FP_X_DNML
    mode &= ~ FP_X_DNML;
#else
  GSL_ERROR ("netbsd-" MACHINE " does not support the denormalized operand exception. "
	     "Use 'mask-denormalized' to work around this.",
	     GSL_EUNSUP);
#endif

  if (exception_mask & GSL_IEEE_MASK_DIVISION_BY_ZERO)
    mode &= ~ FP_X_DZ;

  if (exception_mask & GSL_IEEE_MASK_OVERFLOW)
    mode &= ~ FP_X_OFL;

  if (exception_mask & GSL_IEEE_MASK_UNDERFLOW)
    mode &=  ~ FP_X_UFL;

  if (exception_mask & GSL_IEEE_TRAP_INEXACT)
    {
      mode |= FP_X_IMP;
    }
  else
    {
      mode &= ~ FP_X_IMP;
    }

  fpsetmask (mode);

  return GSL_SUCCESS;

}


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