gcc/config/dfp-bit.c

/* This is a software decimal floating point library.
   Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.

This file is part of GCC.

GCC 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 2, or (at your option) any later
version.

In addition to the permissions in the GNU General Public License, the
Free Software Foundation gives you unlimited permission to link the
compiled version of this file into combinations with other programs,
and to distribute those combinations without any restriction coming
from the use of this file.  (The General Public License restrictions
do apply in other respects; for example, they cover modification of
the file, and distribution when not linked into a combine
executable.)

GCC 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 GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA.  */

/* This implements IEEE 754R decimal floating point arithmetic, but
   does not provide a mechanism for setting the rounding mode, or for
   generating or handling exceptions.  Conversions between decimal
   floating point types and other types depend on C library functions.

   Contributed by Ben Elliston  <bje@au.ibm.com>.  */

#include <stdio.h>
#include <stdlib.h>
/* FIXME: compile with -std=gnu99 to get these from stdlib.h */
extern float strtof (const char *, char **);
extern long double strtold (const char *, char **);
#include <string.h>
#include <limits.h>

#include "config/dfp-bit.h"

/* Forward declarations.  */
#if WIDTH == 32 || WIDTH_TO == 32
void __host_to_ieee_32 (_Decimal32 in, decimal32 *out);
void __ieee_to_host_32 (decimal32 in, _Decimal32 *out);
#endif
#if WIDTH == 64 || WIDTH_TO == 64
void __host_to_ieee_64 (_Decimal64 in, decimal64 *out);
void __ieee_to_host_64 (decimal64 in, _Decimal64 *out);
#endif
#if WIDTH == 128 || WIDTH_TO == 128
void __host_to_ieee_128 (_Decimal128 in, decimal128 *out);
void __ieee_to_host_128 (decimal128 in, _Decimal128 *out);
#endif

/* A pointer to a binary decFloat operation.  */
typedef decFloat* (*dfp_binary_func)
     (decFloat *, const decFloat *, const decFloat *, decContext *);

/* Binary operations.  */

/* Use a decFloat (decDouble or decQuad) function to perform a DFP
   binary operation.  */
static inline decFloat
dfp_binary_op (dfp_binary_func op, decFloat arg_a, decFloat arg_b)
{
  decFloat result;
  decContext context;

  decContextDefault (&context, CONTEXT_INIT);
  DFP_INIT_ROUNDMODE (context.round);

  /* Perform the operation.  */
  op (&result, &arg_a, &arg_b, &context);

  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    {
      /* decNumber exception flags we care about here.  */
      int ieee_flags;
      int dec_flags = DEC_IEEE_854_Division_by_zero | DEC_IEEE_854_Inexact
		      | DEC_IEEE_854_Invalid_operation | DEC_IEEE_854_Overflow
		      | DEC_IEEE_854_Underflow;
      dec_flags &= context.status;
      ieee_flags = DFP_IEEE_FLAGS (dec_flags);
      if (ieee_flags != 0)
        DFP_HANDLE_EXCEPTIONS (ieee_flags);
    }

  return result;
}

#if WIDTH == 32
/* The decNumber package doesn't provide arithmetic for decSingle (32 bits);
   convert to decDouble, use the operation for that, and convert back.  */
static inline _Decimal32
d32_binary_op (dfp_binary_func op, _Decimal32 arg_a, _Decimal32 arg_b)
{
  union { _Decimal32 c; decSingle f; } a32, b32, res32;
  decDouble a, b, res;
  decContext context;

  /* Widen the operands and perform the operation.  */
  a32.c = arg_a;
  b32.c = arg_b;
  decSingleToWider (&a32.f, &a);
  decSingleToWider (&b32.f, &b);
  res = dfp_binary_op (op, a, b);

  /* Narrow the result, which might result in an underflow or overflow.  */
  decContextDefault (&context, CONTEXT_INIT);
  DFP_INIT_ROUNDMODE (context.round);
  decSingleFromWider (&res32.f, &res, &context);
  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    {
      /* decNumber exception flags we care about here.  */
      int ieee_flags;
      int dec_flags = DEC_IEEE_854_Inexact | DEC_IEEE_854_Overflow
		      | DEC_IEEE_854_Underflow;
      dec_flags &= context.status;
      ieee_flags = DFP_IEEE_FLAGS (dec_flags);
      if (ieee_flags != 0)
        DFP_HANDLE_EXCEPTIONS (ieee_flags);
    }

  return res32.c;
}
#else
/* decFloat operations are supported for decDouble (64 bits) and
   decQuad (128 bits).  The bit patterns for the types are the same.  */
static inline DFP_C_TYPE
dnn_binary_op (dfp_binary_func op, DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  union { DFP_C_TYPE c; decFloat f; } a, b, result;

  a.c = arg_a;
  b.c = arg_b;
  result.f = dfp_binary_op (op, a.f, b.f);
  return result.c;
}
#endif

/* Comparison operations.  */

/* Use a decFloat (decDouble or decQuad) function to perform a DFP
   comparison.  */
static inline CMPtype
dfp_compare_op (dfp_binary_func op, decFloat arg_a, decFloat arg_b)
{
  decContext context;
  decFloat res;
  int result;

  decContextDefault (&context, CONTEXT_INIT);
  DFP_INIT_ROUNDMODE (context.round);

  /* Perform the comparison.  */
  op (&res, &arg_a, &arg_b, &context);

  if (DEC_FLOAT_IS_SIGNED (&res))
    result = -1;
  else if (DEC_FLOAT_IS_ZERO (&res))
    result = 0;
  else if (DEC_FLOAT_IS_NAN (&res))
    result = -2;
  else
    result = 1;

  return (CMPtype) result;
}

#if WIDTH == 32
/* The decNumber package doesn't provide comparisons for decSingle (32 bits);
   convert to decDouble, use the operation for that, and convert back.  */
static inline CMPtype
d32_compare_op (dfp_binary_func op, _Decimal32 arg_a, _Decimal32 arg_b)
{
  union { _Decimal32 c; decSingle f; } a32, b32;
  decDouble a, b;

  a32.c = arg_a;
  b32.c = arg_b;
  decSingleToWider (&a32.f, &a);
  decSingleToWider (&b32.f, &b);
  return dfp_compare_op (op, a, b);  
}
#else
/* decFloat comparisons are supported for decDouble (64 bits) and
   decQuad (128 bits).  The bit patterns for the types are the same.  */
static inline CMPtype
dnn_compare_op (dfp_binary_func op, DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  union { DFP_C_TYPE c; decFloat f; } a, b;

  a.c = arg_a;
  b.c = arg_b;
  return dfp_compare_op (op, a.f, b.f);  
}
#endif

#if defined(L_conv_sd)
void
__host_to_ieee_32 (_Decimal32 in, decimal32 *out)
{
  memcpy (out, &in, 4);
}

void
__ieee_to_host_32 (decimal32 in, _Decimal32 *out)
{
  memcpy (out, &in, 4);
}
#endif /* L_conv_sd */

#if defined(L_conv_dd)
void
__host_to_ieee_64 (_Decimal64 in, decimal64 *out)
{
  memcpy (out, &in, 8);
}

void
__ieee_to_host_64 (decimal64 in, _Decimal64 *out)
{
  memcpy (out, &in, 8);
}
#endif /* L_conv_dd */

#if defined(L_conv_td)
void
__host_to_ieee_128 (_Decimal128 in, decimal128 *out)
{
  memcpy (out, &in, 16);
}

void
__ieee_to_host_128 (decimal128 in, _Decimal128 *out)
{
  memcpy (out, &in, 16);
}
#endif /* L_conv_td */

#if defined(L_addsub_sd) || defined(L_addsub_dd) || defined(L_addsub_td)
DFP_C_TYPE
DFP_ADD (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  return DFP_BINARY_OP (DEC_FLOAT_ADD, arg_a, arg_b);
}

DFP_C_TYPE
DFP_SUB (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  return DFP_BINARY_OP (DEC_FLOAT_SUBTRACT, arg_a, arg_b);
}
#endif /* L_addsub */

#if defined(L_mul_sd) || defined(L_mul_dd) || defined(L_mul_td)
DFP_C_TYPE
DFP_MULTIPLY (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  return DFP_BINARY_OP (DEC_FLOAT_MULTIPLY, arg_a, arg_b);
}
#endif /* L_mul */

#if defined(L_div_sd) || defined(L_div_dd) || defined(L_div_td)
DFP_C_TYPE
DFP_DIVIDE (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  return DFP_BINARY_OP (DEC_FLOAT_DIVIDE, arg_a, arg_b);
}
#endif /* L_div */

#if defined (L_eq_sd) || defined (L_eq_dd) || defined (L_eq_td)
CMPtype
DFP_EQ (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  CMPtype stat;
  stat = DFP_COMPARE_OP (DEC_FLOAT_COMPARE, arg_a, arg_b);
  /* For EQ return zero for true, nonzero for false.  */
  return stat != 0;
}
#endif /* L_eq */

#if defined (L_ne_sd) || defined (L_ne_dd) || defined (L_ne_td)
CMPtype
DFP_NE (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  int stat;
  stat = DFP_COMPARE_OP (DEC_FLOAT_COMPARE, arg_a, arg_b);
  /* For NE return zero for true, nonzero for false.  */
  if (__builtin_expect (stat == -2, 0))  /* An operand is NaN.  */
    return 1;
  return stat != 0;
}
#endif /* L_ne */

#if defined (L_lt_sd) || defined (L_lt_dd) || defined (L_lt_td)
CMPtype
DFP_LT (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  int stat;
  stat = DFP_COMPARE_OP (DEC_FLOAT_COMPARE, arg_a, arg_b);
  /* For LT return -1 (<0) for true, 1 for false.  */
  return (stat == -1) ? -1 : 1;
}
#endif /* L_lt */

#if defined (L_gt_sd) || defined (L_gt_dd) || defined (L_gt_td)
CMPtype
DFP_GT (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  int stat;
  stat = DFP_COMPARE_OP (DEC_FLOAT_COMPARE, arg_a, arg_b);
  /* For GT return 1 (>0) for true, -1 for false.  */
  return (stat == 1) ? 1 : -1;
}
#endif

#if defined (L_le_sd) || defined (L_le_dd) || defined (L_le_td)
CMPtype
DFP_LE (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  int stat;
  stat = DFP_COMPARE_OP (DEC_FLOAT_COMPARE, arg_a, arg_b);
  /* For LE return 0 (<= 0) for true, 1 for false.  */
  if (__builtin_expect (stat == -2, 0))  /* An operand is NaN.  */
    return 1;
  return stat == 1;
}
#endif /* L_le */

#if defined (L_ge_sd) || defined (L_ge_dd) || defined (L_ge_td)
CMPtype
DFP_GE (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  int stat;
  stat = DFP_COMPARE_OP (DEC_FLOAT_COMPARE, arg_a, arg_b);
  /* For GE return 1 (>=0) for true, -1 for false.  */
  if (__builtin_expect (stat == -2, 0))  /* An operand is NaN.  */
    return -1;
  return (stat != -1) ? 1 : -1;
}
#endif /* L_ge */

#define BUFMAX 128

/* Check for floating point exceptions that are relevant for conversions
   between decimal float values and handle them.  */
static inline void
dfp_conversion_exceptions (const int status)
{
  /* decNumber exception flags we care about here.  */
  int ieee_flags;
  int dec_flags = DEC_IEEE_854_Inexact | DEC_IEEE_854_Invalid_operation
		  | DEC_IEEE_854_Overflow;
  dec_flags &= status;
  ieee_flags = DFP_IEEE_FLAGS (dec_flags);
  if (ieee_flags != 0)
    DFP_HANDLE_EXCEPTIONS (ieee_flags);
}

#if defined (L_sd_to_dd)
/* Use decNumber to convert directly from _Decimal32 to _Decimal64.  */
_Decimal64
DFP_TO_DFP (_Decimal32 f_from)
{
  union { _Decimal32 c; decSingle f; } from;
  union { _Decimal64 c; decDouble f; } to;

  from.c = f_from;
  to.f = *decSingleToWider (&from.f, &to.f);
  return to.c;
}
#endif

#if defined (L_sd_to_td)
/* Use decNumber to convert directly from _Decimal32 to _Decimal128.  */
_Decimal128
DFP_TO_DFP (_Decimal32 f_from)
{
  union { _Decimal32 c; decSingle f; } from;
  union { _Decimal128 c; decQuad f; } to;
  decDouble temp;

  from.c = f_from;
  temp = *decSingleToWider (&from.f, &temp);
  to.f = *decDoubleToWider (&temp, &to.f);
  return to.c;
}
#endif

#if defined (L_dd_to_td)
/* Use decNumber to convert directly from _Decimal64 to _Decimal128.  */
_Decimal128
DFP_TO_DFP (_Decimal64 f_from)
{
  union { _Decimal64 c; decDouble f; } from;
  union { _Decimal128 c; decQuad f; } to;

  from.c = f_from;
  to.f = *decDoubleToWider (&from.f, &to.f);
  return to.c;
}
#endif

#if defined (L_dd_to_sd)
/* Use decNumber to convert directly from _Decimal64 to _Decimal32.  */
_Decimal32
DFP_TO_DFP (_Decimal64 f_from)
{
  union { _Decimal32 c; decSingle f; } to;
  union { _Decimal64 c; decDouble f; } from;
  decContext context;

  decContextDefault (&context, CONTEXT_INIT);
  DFP_INIT_ROUNDMODE (context.round);
  from.c = f_from;
  to.f = *decSingleFromWider (&to.f, &from.f, &context);
  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    dfp_conversion_exceptions (context.status);
  return to.c;
}
#endif

#if defined (L_td_to_sd)
/* Use decNumber to convert directly from _Decimal128 to _Decimal32.  */
_Decimal32
DFP_TO_DFP (_Decimal128 f_from)
{
  union { _Decimal32 c; decSingle f; } to;
  union { _Decimal128 c; decQuad f; } from;
  decDouble temp;
  decContext context;

  decContextDefault (&context, CONTEXT_INIT);
  DFP_INIT_ROUNDMODE (context.round);
  from.c = f_from;
  temp = *decDoubleFromWider (&temp, &from.f, &context);
  to.f = *decSingleFromWider (&to.f, &temp, &context);
  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    dfp_conversion_exceptions (context.status);
  return to.c;
}
#endif

#if defined (L_td_to_dd)
/* Use decNumber to convert directly from _Decimal128 to _Decimal64.  */
_Decimal64
DFP_TO_DFP (_Decimal128 f_from)
{
  union { _Decimal64 c; decDouble f; } to;
  union { _Decimal128 c; decQuad f; } from;
  decContext context;

  decContextDefault (&context, CONTEXT_INIT);
  DFP_INIT_ROUNDMODE (context.round);
  from.c = f_from;
  to.f = *decDoubleFromWider (&to.f, &from.f, &context);
  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    dfp_conversion_exceptions (context.status);
  return to.c;
}
#endif

#if defined (L_dd_to_si) || defined (L_td_to_si) \
  || defined (L_dd_to_usi) || defined (L_td_to_usi)
/* Use decNumber to convert directly from decimal float to integer types.  */
INT_TYPE
DFP_TO_INT (DFP_C_TYPE x)
{
  union { DFP_C_TYPE c; decFloat f; } u;
  decContext context;
  INT_TYPE i;

  decContextDefault (&context, DEC_INIT_DECIMAL128);
  context.round = DEC_ROUND_DOWN;
  u.c = x;
  i = DEC_FLOAT_TO_INT (&u.f, &context, context.round);
  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    dfp_conversion_exceptions (context.status);
  return i;
}
#endif

#if defined (L_sd_to_si) || (L_sd_to_usi)
/* Use decNumber to convert directly from decimal float to integer types.  */
INT_TYPE
DFP_TO_INT (_Decimal32 x)
{
  union { _Decimal32 c; decSingle f; } u32;
  decDouble f64;
  decContext context;
  INT_TYPE i;

  decContextDefault (&context, DEC_INIT_DECIMAL128);
  context.round = DEC_ROUND_DOWN;
  u32.c = x;
  f64 = *decSingleToWider (&u32.f, &f64);
  i = DEC_FLOAT_TO_INT (&f64, &context, context.round);
  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    dfp_conversion_exceptions (context.status);
  return i;
}
#endif

#if defined (L_sd_to_di) || defined (L_dd_to_di) || defined (L_td_to_di) \
  || defined (L_sd_to_udi) || defined (L_dd_to_udi) || defined (L_td_to_udi)
/* decNumber doesn't provide support for conversions to 64-bit integer
   types, so do it the hard way.  */
INT_TYPE
DFP_TO_INT (DFP_C_TYPE x)
{
  /* decNumber's decimal* types have the same format as C's _Decimal*
     types, but they have different calling conventions.  */

  /* TODO: Decimal float to integer conversions should raise FE_INVALID
     if the result value does not fit into the result type.  */

  IEEE_TYPE s;
  char buf[BUFMAX];
  char *pos;
  decNumber qval, n1, n2;
  decContext context;

  /* Use a large context to avoid losing precision.  */
  decContextDefault (&context, DEC_INIT_DECIMAL128);
  /* Need non-default rounding mode here.  */
  context.round = DEC_ROUND_DOWN;

  HOST_TO_IEEE (x, &s);
  TO_INTERNAL (&s, &n1);
  /* Rescale if the exponent is less than zero.  */
  decNumberToIntegralValue (&n2, &n1, &context);
  /* Get a value to use for the quantize call.  */
  decNumberFromString (&qval, (char *) "1.", &context);
  /* Force the exponent to zero.  */
  decNumberQuantize (&n1, &n2, &qval, &context);
  /* Get a string, which at this point will not include an exponent.  */
  decNumberToString (&n1, buf);
  /* Ignore the fractional part.  */
  pos = strchr (buf, '.');
  if (pos)
    *pos = 0;
  /* Use a C library function to convert to the integral type.  */
  return STR_TO_INT (buf, NULL, 10);
}
#endif

#if defined (L_si_to_dd) || defined (L_si_to_td) \
  || defined (L_usi_to_dd) || defined (L_usi_to_td)
/* Use decNumber to convert directly from integer to decimal float types.  */
DFP_C_TYPE
INT_TO_DFP (INT_TYPE i)
{
  union { DFP_C_TYPE c; decFloat f; } u;

  u.f = *DEC_FLOAT_FROM_INT (&u.f, i);
  return u.c;
}
#endif

#if defined (L_si_to_sd) || defined (L_usi_to_sd)
_Decimal32
/* Use decNumber to convert directly from integer to decimal float types.  */
INT_TO_DFP (INT_TYPE i)
{
  union { _Decimal32 c; decSingle f; } u32;
  decDouble f64;
  decContext context;

  decContextDefault (&context, DEC_INIT_DECIMAL128);
  context.round = DEC_ROUND_DOWN;
  f64 = *DEC_FLOAT_FROM_INT (&f64, i);
  u32.f = *decSingleFromWider (&u32.f, &f64, &context);
  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    dfp_conversion_exceptions (context.status);
  return u32.c;
}
#endif

#if defined (L_di_to_sd) || defined (L_di_to_dd) || defined (L_di_to_td) \
  || defined (L_udi_to_sd) || defined (L_udi_to_dd) || defined (L_udi_to_td)
/* decNumber doesn't provide support for conversions from 64-bit integer
   types, so do it the hard way.  */
DFP_C_TYPE
INT_TO_DFP (INT_TYPE i)
{
  DFP_C_TYPE f;
  IEEE_TYPE s;
  char buf[BUFMAX];
  decContext context;

  decContextDefault (&context, CONTEXT_INIT);
  DFP_INIT_ROUNDMODE (context.round);

  /* Use a C library function to get a floating point string.  */
  sprintf (buf, INT_FMT ".0", CAST_FOR_FMT(i));
  /* Convert from the floating point string to a decimal* type.  */
  FROM_STRING (&s, buf, &context);
  IEEE_TO_HOST (s, &f);

  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    dfp_conversion_exceptions (context.status);

  return f;
}
#endif

#if defined (L_sd_to_sf) || defined (L_dd_to_sf) || defined (L_td_to_sf) \
 || defined (L_sd_to_df) || defined (L_dd_to_df) || defined (L_td_to_df) \
 || ((defined (L_sd_to_xf) || defined (L_dd_to_xf) || defined (L_td_to_xf)) \
     && LONG_DOUBLE_HAS_XF_MODE) \
 || ((defined (L_sd_to_tf) || defined (L_dd_to_tf) || defined (L_td_to_tf)) \
     && LONG_DOUBLE_HAS_TF_MODE)
BFP_TYPE
DFP_TO_BFP (DFP_C_TYPE f)
{
  IEEE_TYPE s;
  char buf[BUFMAX];

  HOST_TO_IEEE (f, &s);
  /* Write the value to a string.  */
  TO_STRING (&s, buf);
  /* Read it as the binary floating point type and return that.  */
  return STR_TO_BFP (buf, NULL);
}
#endif
                                                                                
#if defined (L_sf_to_sd) || defined (L_sf_to_dd) || defined (L_sf_to_td) \
 || defined (L_df_to_sd) || defined (L_df_to_dd) || defined (L_df_to_td) \
 || ((defined (L_xf_to_sd) || defined (L_xf_to_dd) || defined (L_xf_to_td)) \
     && LONG_DOUBLE_HAS_XF_MODE) \
 || ((defined (L_tf_to_sd) || defined (L_tf_to_dd) || defined (L_tf_to_td)) \
     && LONG_DOUBLE_HAS_TF_MODE)
DFP_C_TYPE
BFP_TO_DFP (BFP_TYPE x)
{
  DFP_C_TYPE f;
  IEEE_TYPE s;
  char buf[BUFMAX];
  decContext context;

  decContextDefault (&context, CONTEXT_INIT);
  DFP_INIT_ROUNDMODE (context.round);

  /* Use a C library function to write the floating point value to a string.  */
  sprintf (buf, BFP_FMT, (BFP_VIA_TYPE) x);

  /* Convert from the floating point string to a decimal* type.  */
  FROM_STRING (&s, buf, &context);
  IEEE_TO_HOST (s, &f);

  if (DFP_EXCEPTIONS_ENABLED && context.status != 0)
    {
      /* decNumber exception flags we care about here.  */
      int ieee_flags;
      int dec_flags = DEC_IEEE_854_Inexact | DEC_IEEE_854_Invalid_operation
		      | DEC_IEEE_854_Overflow | DEC_IEEE_854_Underflow;
      dec_flags &= context.status;
      ieee_flags = DFP_IEEE_FLAGS (dec_flags);
      if (ieee_flags != 0)
        DFP_HANDLE_EXCEPTIONS (ieee_flags);
    }

  return f;
}
#endif

#if defined (L_unord_sd) || defined (L_unord_dd) || defined (L_unord_td)
CMPtype
DFP_UNORD (DFP_C_TYPE arg_a, DFP_C_TYPE arg_b)
{
  decNumber arg1, arg2;
  IEEE_TYPE a, b;

  HOST_TO_IEEE (arg_a, &a);
  HOST_TO_IEEE (arg_b, &b);
  TO_INTERNAL (&a, &arg1);
  TO_INTERNAL (&b, &arg2);
  return (decNumberIsNaN (&arg1) || decNumberIsNaN (&arg2));
}
#endif /* L_unord_sd || L_unord_dd || L_unord_td */