gcc/libdecnumber/decimal128.h

/* Decimal 128-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(DECIMAL128)
#define DECIMAL128
#define DEC128NAME     "decimal128"	/* Short name */
#define DEC128FULLNAME "Decimal 128-bit Number"	/* Verbose name */
#define DEC128AUTHOR   "Mike Cowlishaw"	/* Who to blame */

#if defined(DECIMAL32)
#error decimal128.h must precede decimal32.h for correct DECNUMDIGITS
#else
#if defined(DECIMAL64)
#error decimal128.h must precede decimal64.h for correct DECNUMDIGITS
#endif
#endif

  /* parameters for decimal128s */
#define DECIMAL128_Bytes  16	/* length */
#define DECIMAL128_Pmax   34	/* maximum precision (digits) */
#define DECIMAL128_Emax   6144	/* maximum adjusted exponent */
#define DECIMAL128_Emin  -6143	/* minimum adjusted exponent */
#define DECIMAL128_Bias   6176	/* bias for the exponent */
#define DECIMAL128_String 43	/* maximum string length, +1 */
  /* highest biased exponent (Elimit-1) */
#define DECIMAL128_Ehigh  (DECIMAL128_Emax+DECIMAL128_Bias-DECIMAL128_Pmax+1)

#ifndef DECNUMDIGITS
#define DECNUMDIGITS DECIMAL128_Pmax	/* size if not already defined */
#endif
#ifndef DECNUMBER
#include "decNumber.h"		/* context and number library */
#endif

  /* Decimal 128-bit type, accessible by bytes */
typedef struct
{
  uint8_t bytes[DECIMAL128_Bytes];	/* decimal128: 1, 5, 12, 110 bits */
} decimal128;

  /* 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 decimal128 fields.  These assume the argument
     is a reference (pointer) to the decimal128 structure */
  /* Get sign */
#define decimal128Sign(d)       ((unsigned)(d)->bytes[0]>>7)

  /* Get combination field */
#define decimal128Comb(d)       (((d)->bytes[0] & 0x7c)>>2)

  /* Get exponent continuation [does not remove bias] */
#define decimal128ExpCon(d)     ((((d)->bytes[0] & 0x03)<<10)       \
                                | ((unsigned)(d)->bytes[1]<<2)        \
                                | ((unsigned)(d)->bytes[2]>>6))

  /* Set sign [this assumes sign previously 0] */
#define decimal128SetSign(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 decimal128SetExpCon(d, e) {                                 \
    (d)->bytes[0]|=(uint8_t)((e)>>10);                                \
    (d)->bytes[1] =(uint8_t)(((e)&0x3fc)>>2);                         \
    (d)->bytes[2]|=(uint8_t)(((e)&0x03)<<6);}

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

#ifdef IN_LIBGCC2
#define decimal128FromString __decimal128FromString
#define decimal128ToString __decimal128ToString
#define decimal128ToEngString __decimal128ToEngString
#define decimal128FromNumber __decimal128FromNumber
#define decimal128ToNumber __decimal128ToNumber
#endif

  /* String conversions */
decimal128 *decimal128FromString (decimal128 *, char *, decContext *);
char *decimal128ToString (decimal128 *, char *);
char *decimal128ToEngString (decimal128 *, char *);

  /* decNumber conversions */
decimal128 *decimal128FromNumber (decimal128 *, decNumber *, decContext *);
decNumber *decimal128ToNumber (decimal128 *, decNumber *);

#endif