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    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(DECIMAL32)
  23 #define DECIMAL32
  24 #define DEC32NAME     "decimal32"       /* Short name */
  25 #define DEC32FULLNAME "Decimal 32-bit Number"   /* Verbose name */
  26 #define DEC32AUTHOR   "Mike Cowlishaw"  /* Who to blame */
  27
  28   /* parameters for decimal32s */
  29 #define DECIMAL32_Bytes  4      /* length */
  30 #define DECIMAL32_Pmax   7      /* maximum precision (digits) */
  31 #define DECIMAL32_Emax   96     /* maximum adjusted exponent */
  32 #define DECIMAL32_Emin  -95     /* minimum adjusted exponent */
  33 #define DECIMAL32_Bias   101    /* bias for the exponent */
  34 #define DECIMAL32_String 15     /* maximum string length, +1 */
  35   /* highest biased exponent (Elimit-1) */
  36 #define DECIMAL32_Ehigh  (DECIMAL32_Emax+DECIMAL32_Bias-DECIMAL32_Pmax+1)
  37
  38 #ifndef DECNUMDIGITS
  39 #define DECNUMDIGITS DECIMAL32_Pmax     /* size if not already defined */
  40 #endif
  41 #ifndef DECNUMBER
  42 #include "decNumber.h"          /* context and number library */
  43 #endif
  44
  45   /* Decimal 32-bit type, accessible by bytes */
  46 typedef struct
  47 {
  48   uint8_t bytes[DECIMAL32_Bytes];       /* decimal32: 1, 5, 6, 20 bits */
  49 } decimal32;
  50
  51   /* special values [top byte excluding sign bit; last two bits are
  52      don't-care for Infinity on input, last bit don't-care for NaN] */
  53 #if !defined(DECIMAL_NaN)
  54 #define DECIMAL_NaN     0x7c    /* 0 11111 00 NaN */
  55 #define DECIMAL_sNaN    0x7e    /* 0 11111 10 sNaN */
  56 #define DECIMAL_Inf     0x78    /* 0 11110 00 Infinity */
  57 #endif
  58
  59   /* Macros for accessing decimal32 fields.  These assume the argument
  60      is a reference (pointer) to the decimal32 structure */
  61   /* Get sign */
  62 #define decimal32Sign(d)       ((unsigned)(d)->bytes[0]>>7)
  63
  64   /* Get combination field */
  65 #define decimal32Comb(d)       (((d)->bytes[0] & 0x7c)>>2)
  66
  67   /* Get exponent continuation [does not remove bias] */
  68 #define decimal32ExpCon(d)     ((((d)->bytes[0] & 0x03)<<4)         \
  69                                | ((unsigned)(d)->bytes[1]>>4))
  70
  71   /* Set sign [this assumes sign previously 0] */
  72 #define decimal32SetSign(d, b) {                                    \
  73     (d)->bytes[0]|=((unsigned)(b)<<7);}
  74
  75   /* Set exponent continuation [does not apply bias] */
  76   /* This assumes range has been checked and exponent previously 0; */
  77   /* type of exponent must be unsigned */
  78 #define decimal32SetExpCon(d, e) {                                  \
  79     (d)->bytes[0]|=(uint8_t)((e)>>4);                                 \
  80     (d)->bytes[1]|=(uint8_t)(((e)&0x0F)<<4);}
  81
  82   /* ------------------------------------------------------------------ */
  83   /* Routines                                                           */
  84   /* ------------------------------------------------------------------ */
  85
  86 #ifdef IN_LIBGCC2
  87 #define decimal32FromString __decimal32FromString
  88 #define decimal32ToString __decimal32ToString
  89 #define decimal32ToEngString __decimal32ToEngString
  90 #define decimal32FromNumber __decimal32FromNumber
  91 #define decimal32ToNumber __decimal32ToNumber
  92 #endif
  93
  94 /* String conversions.  */
  95 decimal32 *decimal32FromString (decimal32 *, const char *, decContext *);
  96 char *decimal32ToString (const decimal32 *, char *);
  97 char *decimal32ToEngString (const decimal32 *, char *);
  98
  99 /* decNumber conversions.  */
 100 decimal32 *decimal32FromNumber (decimal32 *, const decNumber *, decContext *);
 101 decNumber *decimal32ToNumber (const decimal32 *, decNumber *);
 102
 103 #endif