src/decNumber/decimal128.h

/* */
   1 // vim: filetype=c:tabstop=4:ai:expandtab
   2 // SPDX-License-Identifier: ICU
   3 // scspell-id: b69cc81e-f62c-11ec-a05b-80ee73e9b8e7
   4 /* ------------------------------------------------------------------- */
   5 /* Decimal 128-bit format module header                                */
   6 /* ------------------------------------------------------------------- */
   7 /*                                                                     */
   8 /* Copyright (c) IBM Corporation, 2000, 2005.  All rights reserved.    */
   9 /*                                                                     */
  10 /* This software is made available under the terms of the ICU License. */
  11 /*                                                                     */
  12 /* The description and User's Guide ("The decNumber C Library") for    */
  13 /* this software is called decNumber.pdf.  This document is available, */
  14 /* together with arithmetic and format specifications, testcases, and  */
  15 /* Web links, on the General Decimal Arithmetic page.                  */
  16 /*                                                                     */
  17 /* Please send comments, suggestions, and corrections to the author:   */
  18 /*   mfc@uk.ibm.com                                                    */
  19 /*   Mike Cowlishaw, IBM Fellow                                        */
  20 /*   IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK          */
  21 /*                                                                     */
  22 /* ------------------------------------------------------------------- */
  23 
  24 #if !defined(DECIMAL128)
  25 # define DECIMAL128
  26 # define DEC128NAME     "decimal128"                  /* Short name   */
  27 # define DEC128FULLNAME "Decimal 128-bit Number"      /* Verbose name */
  28 # define DEC128AUTHOR   "Mike Cowlishaw"              /* Who to blame */
  29 
  30   /* parameters for decimal128s */
  31 # define DECIMAL128_Bytes  16           /* length                     */
  32 # define DECIMAL128_Pmax   34           /* maximum precision (digits) */
  33 # define DECIMAL128_Emax   6144         /* maximum adjusted exponent  */
  34 # define DECIMAL128_Emin  -6143         /* minimum adjusted exponent  */
  35 # define DECIMAL128_Bias   6176         /* bias for the exponent      */
  36 # define DECIMAL128_String 43           /* maximum string length, +1  */
  37 # define DECIMAL128_EconL  12           /* exp. continuation length   */
  38   /* highest biased exponent (Elimit-1)                               */
  39 # define DECIMAL128_Ehigh                                              \
  40     (DECIMAL128_Emax+DECIMAL128_Bias-DECIMAL128_Pmax+1)
  41 
  42   /* check enough digits, if pre-defined                              */
  43 # if defined(DECNUMDIGITS)
  44 #  if (DECNUMDIGITS<DECIMAL128_Pmax)
  45 #   error decimal128.h needs pre-defined DECNUMDIGITS>=34 for safe use
  46 #  endif
  47 # endif
  48 
  49 # if !defined(DECNUMDIGITS)
  50 #  define DECNUMDIGITS DECIMAL128_Pmax /* size if not already defined */
  51 # endif /* if !defined(DECNUMDIGITS) */
  52 # if !defined(DECNUMBER)
  53 #  include "decNumber.h"                /* context and number library */
  54 # endif /* if !defined(DECNUMBER) */
  55 
  56   /* Decimal 128-bit type, accessible by bytes                        */
  57   typedef struct {
  58     uint8_t bytes[DECIMAL128_Bytes]; /* decimal128: 1, 5, 12, 110 bits*/
  59     } decimal128;
  60 
  61   /* special values [top byte excluding sign bit; last two bits are   */
  62   /* don't-care for Infinity on input, last bit don't-care for NaN]   */
  63 # if !defined(DECIMAL_NaN)
  64 #  define DECIMAL_NaN     0x7c          /* 0 11111 00 NaN             */
  65 #  define DECIMAL_sNaN    0x7e          /* 0 11111 10 sNaN            */
  66 #  define DECIMAL_Inf     0x78          /* 0 11110 00 Infinity        */
  67 # endif
  68 
  69   /* ---------------------------------------------------------------- */
  70   /* Routines                                                         */
  71   /* ---------------------------------------------------------------- */
  72   /* String conversions                                               */
  73   decimal128 * decimal128FromString(decimal128 *, const char *,
  74     decContext *);
  75   char * decimal128ToString(const decimal128 *, char *);
  76   char * decimal128ToEngString(const decimal128 *, char *);
  77 
  78   /* decNumber conversions                                            */
  79   decimal128 * decimal128FromNumber(decimal128 *, const decNumber *,
  80                                     decContext *);
  81   decNumber * decimal128ToNumber(const decimal128 *, decNumber *);
  82 
  83   /* Format-dependent utilities                                       */
  84   uint32_t    decimal128IsCanonical(const decimal128 *);
  85   decimal128 * decimal128Canonical(decimal128 *, const decimal128 *);
  86 
  87 #endif
/* */
root/src/decNumber/decimal128.h
