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    In addition to the permissions in the GNU General Public License,
  13    the Free Software Foundation gives you unlimited permission to link
  14    the compiled version of this file into combinations with other
  15    programs, and to distribute those combinations without any
  16    restriction coming from the use of this file.  (The General Public
  17    License restrictions do apply in other respects; for example, they
  18    cover modification of the file, and distribution when not linked
  19    into a combine executable.)
  20
  21    GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  22    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  23    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  24    for more details.
  25
  26    You should have received a copy of the GNU General Public License
  27    along with GCC; see the file COPYING.  If not, write to the Free
  28    Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  29    02110-1301, USA.  */
  30
  31 #if !defined(DECIMAL64)
  32 #define DECIMAL64
  33 #define DEC64NAME     "decimal64"       /* Short name */
  34 #define DEC64FULLNAME "Decimal 64-bit Number"   /* Verbose name */
  35 #define DEC64AUTHOR   "Mike Cowlishaw"  /* Who to blame */
  36
  37 #if defined(DECIMAL32)
  38 #error decimal64.h must precede decimal32.h for correct DECNUMDIGITS
  39 #endif
  40
  41   /* parameters for decimal64s */
  42 #define DECIMAL64_Bytes  8      /* length */
  43 #define DECIMAL64_Pmax   16     /* maximum precision (digits) */
  44 #define DECIMAL64_Emax   384    /* maximum adjusted exponent */
  45 #define DECIMAL64_Emin  -383    /* minimum adjusted exponent */
  46 #define DECIMAL64_Bias   398    /* bias for the exponent */
  47 #define DECIMAL64_String 24     /* maximum string length, +1 */
  48   /* highest biased exponent (Elimit-1) */
  49 #define DECIMAL64_Ehigh  (DECIMAL64_Emax+DECIMAL64_Bias-DECIMAL64_Pmax+1)
  50
  51 #ifndef DECNUMDIGITS
  52 #define DECNUMDIGITS DECIMAL64_Pmax     /* size if not already defined */
  53 #endif
  54 #ifndef DECNUMBER
  55 #include "decNumber.h"          /* context and number library */
  56 #endif
  57
  58   /* Decimal 64-bit type, accessible by bytes */
  59 typedef struct
  60 {
  61   uint8_t bytes[DECIMAL64_Bytes];       /* decimal64: 1, 5, 8, 50 bits */
  62 } decimal64;
  63
  64   /* special values [top byte excluding sign bit; last two bits are
  65      don't-care for Infinity on input, last bit don't-care for NaN] */
  66 #if !defined(DECIMAL_NaN)
  67 #define DECIMAL_NaN     0x7c    /* 0 11111 00 NaN */
  68 #define DECIMAL_sNaN    0x7e    /* 0 11111 10 sNaN */
  69 #define DECIMAL_Inf     0x78    /* 0 11110 00 Infinity */
  70 #endif
  71
  72   /* Macros for accessing decimal64 fields.  These assume the argument
  73      is a reference (pointer) to the decimal64 structure */
  74   /* Get sign */
  75 #define decimal64Sign(d)       ((unsigned)(d)->bytes[0]>>7)
  76
  77   /* Get combination field */
  78 #define decimal64Comb(d)       (((d)->bytes[0] & 0x7c)>>2)
  79
  80   /* Get exponent continuation [does not remove bias] */
  81 #define decimal64ExpCon(d)     ((((d)->bytes[0] & 0x03)<<6)         \
  82                                | ((unsigned)(d)->bytes[1]>>2))
  83
  84   /* Set sign [this assumes sign previously 0] */
  85 #define decimal64SetSign(d, b) {                                    \
  86     (d)->bytes[0]|=((unsigned)(b)<<7);}
  87
  88   /* Set exponent continuation [does not apply bias] */
  89   /* This assumes range has been checked and exponent previously 0; type */
  90   /* of exponent must be unsigned */
  91 #define decimal64SetExpCon(d, e) {                                  \
  92     (d)->bytes[0]|=(uint8_t)((e)>>6);                                 \
  93     (d)->bytes[1]|=(uint8_t)(((e)&0x3F)<<2);}
  94
  95   /* ------------------------------------------------------------------ */
  96   /* Routines                                                           */
  97   /* ------------------------------------------------------------------ */
  98
  99 #ifdef IN_LIBGCC2
 100 #define decimal64FromString __decimal64FromString
 101 #define decimal64ToString __decimal64ToString
 102 #define decimal64ToEngString __decimal64ToEngString
 103 #define decimal64FromNumber __decimal64FromNumber
 104 #define decimal64ToNumber __decimal64ToNumber
 105 #endif
 106
 107   /* String conversions */
 108 decimal64 *decimal64FromString (decimal64 *, const char *, decContext *);
 109 char *decimal64ToString (const decimal64 *, char *);
 110 char *decimal64ToEngString (const decimal64 *, char *);
 111
 112   /* decNumber conversions */
 113 decimal64 *decimal64FromNumber (decimal64 *, const decNumber *, decContext *);
 114 decNumber *decimal64ToNumber (const decimal64 *, decNumber *);
 115
 116 #endif