libdecnumber/decimal32.h

   1 /* Decimal 32-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(DECIMAL32)
  32 #define DECIMAL32
  33 #define DEC32NAME     "decimal32"       /* Short name */
  34 #define DEC32FULLNAME "Decimal 32-bit Number"   /* Verbose name */
  35 #define DEC32AUTHOR   "Mike Cowlishaw"  /* Who to blame */
  36
  37   /* parameters for decimal32s */
  38 #define DECIMAL32_Bytes  4      /* length */
  39 #define DECIMAL32_Pmax   7      /* maximum precision (digits) */
  40 #define DECIMAL32_Emax   96     /* maximum adjusted exponent */
  41 #define DECIMAL32_Emin  -95     /* minimum adjusted exponent */
  42 #define DECIMAL32_Bias   101    /* bias for the exponent */
  43 #define DECIMAL32_String 15     /* maximum string length, +1 */
  44   /* highest biased exponent (Elimit-1) */
  45 #define DECIMAL32_Ehigh  (DECIMAL32_Emax+DECIMAL32_Bias-DECIMAL32_Pmax+1)
  46
  47 #ifndef DECNUMDIGITS
  48 #define DECNUMDIGITS DECIMAL32_Pmax     /* size if not already defined */
  49 #endif
  50 #ifndef DECNUMBER
  51 #include "decNumber.h"          /* context and number library */
  52 #endif
  53
  54   /* Decimal 32-bit type, accessible by bytes */
  55 typedef struct
  56 {
  57   uint8_t bytes[DECIMAL32_Bytes];       /* decimal32: 1, 5, 6, 20 bits */
  58 } decimal32;
  59
  60   /* special values [top byte excluding sign bit; last two bits are
  61      don't-care for Infinity on input, last bit don't-care for NaN] */
  62 #if !defined(DECIMAL_NaN)
  63 #define DECIMAL_NaN     0x7c    /* 0 11111 00 NaN */
  64 #define DECIMAL_sNaN    0x7e    /* 0 11111 10 sNaN */
  65 #define DECIMAL_Inf     0x78    /* 0 11110 00 Infinity */
  66 #endif
  67
  68   /* Macros for accessing decimal32 fields.  These assume the argument
  69      is a reference (pointer) to the decimal32 structure */
  70   /* Get sign */
  71 #define decimal32Sign(d)       ((unsigned)(d)->bytes[0]>>7)
  72
  73   /* Get combination field */
  74 #define decimal32Comb(d)       (((d)->bytes[0] & 0x7c)>>2)
  75
  76   /* Get exponent continuation [does not remove bias] */
  77 #define decimal32ExpCon(d)     ((((d)->bytes[0] & 0x03)<<4)         \
  78                                | ((unsigned)(d)->bytes[1]>>4))
  79
  80   /* Set sign [this assumes sign previously 0] */
  81 #define decimal32SetSign(d, b) {                                    \
  82     (d)->bytes[0]|=((unsigned)(b)<<7);}
  83
  84   /* Set exponent continuation [does not apply bias] */
  85   /* This assumes range has been checked and exponent previously 0; */
  86   /* type of exponent must be unsigned */
  87 #define decimal32SetExpCon(d, e) {                                  \
  88     (d)->bytes[0]|=(uint8_t)((e)>>4);                                 \
  89     (d)->bytes[1]|=(uint8_t)(((e)&0x0F)<<4);}
  90
  91   /* ------------------------------------------------------------------ */
  92   /* Routines                                                           */
  93   /* ------------------------------------------------------------------ */
  94
  95 #ifdef IN_LIBGCC2
  96 #define decimal32FromString __decimal32FromString
  97 #define decimal32ToString __decimal32ToString
  98 #define decimal32ToEngString __decimal32ToEngString
  99 #define decimal32FromNumber __decimal32FromNumber
 100 #define decimal32ToNumber __decimal32ToNumber
 101 #endif
 102
 103 /* String conversions.  */
 104 decimal32 *decimal32FromString (decimal32 *, const char *, decContext *);
 105 char *decimal32ToString (const decimal32 *, char *);
 106 char *decimal32ToEngString (const decimal32 *, char *);
 107
 108 /* decNumber conversions.  */
 109 decimal32 *decimal32FromNumber (decimal32 *, const decNumber *, decContext *);
 110 decNumber *decimal32ToNumber (const decimal32 *, decNumber *);
 111
 112 #endif