libdecnumber/decimal64.h

   1 /* Decimal 64-bit format module header for the decNumber C Library
   2    Copyright (C) 2005 Free Software Foundation, Inc.
   3    Contributed by IBM Corporation.  Author Mike Cowlishaw.
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify it under
   8    the terms of the GNU General Public License as published by the Free
   9    Software Foundation; either version 2, or (at your option) any later
  10    version.
  11
  12    GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15    for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GCC; see the file COPYING.  If not, write to the Free
  19    Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  20    02110-1301, USA.  */
  21
  22 #if !defined(DECIMAL64)
  23 #define DECIMAL64
  24 #define DEC64NAME     "decimal64"       /* Short name */
  25 #define DEC64FULLNAME "Decimal 64-bit Number"   /* Verbose name */
  26 #define DEC64AUTHOR   "Mike Cowlishaw"  /* Who to blame */
  27
  28 #if defined(DECIMAL32)
  29 #error decimal64.h must precede decimal32.h for correct DECNUMDIGITS
  30 #endif
  31
  32   /* parameters for decimal64s */
  33 #define DECIMAL64_Bytes  8      /* length */
  34 #define DECIMAL64_Pmax   16     /* maximum precision (digits) */
  35 #define DECIMAL64_Emax   384    /* maximum adjusted exponent */
  36 #define DECIMAL64_Emin  -383    /* minimum adjusted exponent */
  37 #define DECIMAL64_Bias   398    /* bias for the exponent */
  38 #define DECIMAL64_String 24     /* maximum string length, +1 */
  39   /* highest biased exponent (Elimit-1) */
  40 #define DECIMAL64_Ehigh  (DECIMAL64_Emax+DECIMAL64_Bias-DECIMAL64_Pmax+1)
  41
  42 #ifndef DECNUMDIGITS
  43 #define DECNUMDIGITS DECIMAL64_Pmax     /* size if not already defined */
  44 #endif
  45 #ifndef DECNUMBER
  46 #include "decNumber.h"          /* context and number library */
  47 #endif
  48
  49   /* Decimal 64-bit type, accessible by bytes */
  50 typedef struct
  51 {
  52   uint8_t bytes[DECIMAL64_Bytes];       /* decimal64: 1, 5, 8, 50 bits */
  53 } decimal64;
  54
  55   /* special values [top byte excluding sign bit; last two bits are
  56      don't-care for Infinity on input, last bit don't-care for NaN] */
  57 #if !defined(DECIMAL_NaN)
  58 #define DECIMAL_NaN     0x7c    /* 0 11111 00 NaN */
  59 #define DECIMAL_sNaN    0x7e    /* 0 11111 10 sNaN */
  60 #define DECIMAL_Inf     0x78    /* 0 11110 00 Infinity */
  61 #endif
  62
  63   /* Macros for accessing decimal64 fields.  These assume the argument
  64      is a reference (pointer) to the decimal64 structure */
  65   /* Get sign */
  66 #define decimal64Sign(d)       ((unsigned)(d)->bytes[0]>>7)
  67
  68   /* Get combination field */
  69 #define decimal64Comb(d)       (((d)->bytes[0] & 0x7c)>>2)
  70
  71   /* Get exponent continuation [does not remove bias] */
  72 #define decimal64ExpCon(d)     ((((d)->bytes[0] & 0x03)<<6)         \
  73                                | ((unsigned)(d)->bytes[1]>>2))
  74
  75   /* Set sign [this assumes sign previously 0] */
  76 #define decimal64SetSign(d, b) {                                    \
  77     (d)->bytes[0]|=((unsigned)(b)<<7);}
  78
  79   /* Set exponent continuation [does not apply bias] */
  80   /* This assumes range has been checked and exponent previously 0; type */
  81   /* of exponent must be unsigned */
  82 #define decimal64SetExpCon(d, e) {                                  \
  83     (d)->bytes[0]|=(uint8_t)((e)>>6);                                 \
  84     (d)->bytes[1]|=(uint8_t)(((e)&0x3F)<<2);}
  85
  86   /* ------------------------------------------------------------------ */
  87   /* Routines                                                           */
  88   /* ------------------------------------------------------------------ */
  89
  90 #ifdef IN_LIBGCC2
  91 #define decimal64FromString __decimal64FromString
  92 #define decimal64ToString __decimal64ToString
  93 #define decimal64ToEngString __decimal64ToEngString
  94 #define decimal64FromNumber __decimal64FromNumber
  95 #define decimal64ToNumber __decimal64ToNumber
  96 #endif
  97
  98   /* String conversions */
  99 decimal64 *decimal64FromString (decimal64 *, char *, decContext *);
 100 char *decimal64ToString (decimal64 *, char *);
 101 char *decimal64ToEngString (decimal64 *, char *);
 102
 103   /* decNumber conversions */
 104 decimal64 *decimal64FromNumber (decimal64 *, decNumber *, decContext *);
 105 decNumber *decimal64ToNumber (decimal64 *, decNumber *);
 106
 107 #endif