gcc/libdecnumber/decimal64.h

/* Decimal 64-bit format module header for the decNumber C Library
   Copyright (C) 2005 Free Software Foundation, Inc.
   Contributed by IBM Corporation.  Author Mike Cowlishaw.

   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.

   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.  */

#if !defined(DECIMAL64)
#define DECIMAL64
#define DEC64NAME     "decimal64"	/* Short name */
#define DEC64FULLNAME "Decimal 64-bit Number"	/* Verbose name */
#define DEC64AUTHOR   "Mike Cowlishaw"	/* Who to blame */

#if defined(DECIMAL32)
#error decimal64.h must precede decimal32.h for correct DECNUMDIGITS
#endif

  /* parameters for decimal64s */
#define DECIMAL64_Bytes  8	/* length */
#define DECIMAL64_Pmax   16	/* maximum precision (digits) */
#define DECIMAL64_Emax   384	/* maximum adjusted exponent */
#define DECIMAL64_Emin  -383	/* minimum adjusted exponent */
#define DECIMAL64_Bias   398	/* bias for the exponent */
#define DECIMAL64_String 24	/* maximum string length, +1 */
  /* highest biased exponent (Elimit-1) */
#define DECIMAL64_Ehigh  (DECIMAL64_Emax+DECIMAL64_Bias-DECIMAL64_Pmax+1)

#ifndef DECNUMDIGITS
#define DECNUMDIGITS DECIMAL64_Pmax	/* size if not already defined */
#endif
#ifndef DECNUMBER
#include "decNumber.h"		/* context and number library */
#endif

  /* Decimal 64-bit type, accessible by bytes */
typedef struct
{
  uint8_t bytes[DECIMAL64_Bytes];	/* decimal64: 1, 5, 8, 50 bits */
} decimal64;

  /* special values [top byte excluding sign bit; last two bits are
     don't-care for Infinity on input, last bit don't-care for NaN] */
#if !defined(DECIMAL_NaN)
#define DECIMAL_NaN     0x7c	/* 0 11111 00 NaN */
#define DECIMAL_sNaN    0x7e	/* 0 11111 10 sNaN */
#define DECIMAL_Inf     0x78	/* 0 11110 00 Infinity */
#endif

  /* Macros for accessing decimal64 fields.  These assume the argument
     is a reference (pointer) to the decimal64 structure */
  /* Get sign */
#define decimal64Sign(d)       ((unsigned)(d)->bytes[0]>>7)

  /* Get combination field */
#define decimal64Comb(d)       (((d)->bytes[0] & 0x7c)>>2)

  /* Get exponent continuation [does not remove bias] */
#define decimal64ExpCon(d)     ((((d)->bytes[0] & 0x03)<<6)         \
                               | ((unsigned)(d)->bytes[1]>>2))

  /* Set sign [this assumes sign previously 0] */
#define decimal64SetSign(d, b) {                                    \
    (d)->bytes[0]|=((unsigned)(b)<<7);}

  /* Set exponent continuation [does not apply bias] */
  /* This assumes range has been checked and exponent previously 0; type */
  /* of exponent must be unsigned */
#define decimal64SetExpCon(d, e) {                                  \
    (d)->bytes[0]|=(uint8_t)((e)>>6);                                 \
    (d)->bytes[1]|=(uint8_t)(((e)&0x3F)<<2);}

  /* ------------------------------------------------------------------ */
  /* Routines                                                           */
  /* ------------------------------------------------------------------ */

#ifdef IN_LIBGCC2
#define decimal64FromString __decimal64FromString
#define decimal64ToString __decimal64ToString
#define decimal64ToEngString __decimal64ToEngString
#define decimal64FromNumber __decimal64FromNumber
#define decimal64ToNumber __decimal64ToNumber
#endif

  /* String conversions */
decimal64 *decimal64FromString (decimal64 *, const char *, decContext *);
char *decimal64ToString (const decimal64 *, char *);
char *decimal64ToEngString (const decimal64 *, char *);

  /* decNumber conversions */
decimal64 *decimal64FromNumber (decimal64 *, const decNumber *, decContext *);
decNumber *decimal64ToNumber (const decimal64 *, decNumber *);

#endif