decnumber-sys 0.1.6

Low-level bindings for libdecnumber.
Documentation 
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/* ------------------------------------------------------------------ */
/* Decimal 64-bit format module header                                */
/* ------------------------------------------------------------------ */
/* Copyright (c) IBM Corporation, 2000, 2005.  All rights reserved.   */
/*                                                                    */
/* This software is made available under the terms of the             */
/* ICU License -- ICU 1.8.1 and later.                                */
/*                                                                    */
/* The description and User's Guide ("The decNumber C Library") for   */
/* this software is called decNumber.pdf.  This document is           */
/* available, together with arithmetic and format specifications,     */
/* testcases, and Web links, on the General Decimal Arithmetic page.  */
/*                                                                    */
/* Please send comments, suggestions, and corrections to the author:  */
/*   mfc@uk.ibm.com                                                   */
/*   Mike Cowlishaw, IBM Fellow                                       */
/*   IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK         */
/* ------------------------------------------------------------------ */

#if !defined(DECIMAL64)
  #define DECIMAL64
  #define DEC64NAME     "decimal64"                   /* Short name   */
  #define DEC64FULLNAME "Decimal 64-bit Number"       /* Verbose name */
  #define DEC64AUTHOR   "Mike Cowlishaw"              /* Who to blame */


  /* parameters for decimal64s                                        */
  #define DECIMAL64_Bytes  8            /* length                     */
  #define DECIMAL64_Pmax   16           /* maximum precision (digits) */
  #define DECIMAL64_Emax   384          /* maximum adjusted exponent  */
  #define DECIMAL64_Emin  -383          /* minimum adjusted exponent  */
  #define DECIMAL64_Bias   398          /* bias for the exponent      */
  #define DECIMAL64_String 24           /* maximum string length, +1  */
  #define DECIMAL64_EconL  8            /* exp. continuation length   */
  /* highest biased exponent (Elimit-1)                               */
  #define DECIMAL64_Ehigh  (DECIMAL64_Emax+DECIMAL64_Bias-DECIMAL64_Pmax+1)

  /* check enough digits, if pre-defined                              */
  #if defined(DECNUMDIGITS)
    #if (DECNUMDIGITS<DECIMAL64_Pmax)
      #error decimal64.h needs pre-defined DECNUMDIGITS>=16 for safe use
    #endif
  #endif


  #ifndef DECNUMDIGITS
    #define DECNUMDIGITS DECIMAL64_Pmax /* size if not already defined*/
  #endif
  #ifndef DECNUMBER
    #include "decNumber.h"              /* context and number library */
  #endif

  /* Decimal 64-bit type, accessible by bytes                         */
  typedef union {
    uint8_t bytes[DECIMAL64_Bytes];     /* decimal64: 1, 5, 8, 50 bits*/
    uint16_t shorts[DECIMAL64_Bytes/2];
    uint32_t  words[DECIMAL64_Bytes/4];
    #if DECUSE64
    uint64_t  longs[DECIMAL64_Bytes/8];
    #endif
    } decimal64;

  /* special values [top byte excluding sign bit; last two bits are   */
  /* don't-care for Infinity on input, last bit don't-care for NaN]   */
  #if !defined(DECIMAL_NaN)
    #define DECIMAL_NaN     0x7c        /* 0 11111 00 NaN             */
    #define DECIMAL_sNaN    0x7e        /* 0 11111 10 sNaN            */
    #define DECIMAL_Inf     0x78        /* 0 11110 00 Infinity        */
  #endif

  /* ---------------------------------------------------------------- */
  /* Routines                                                         */
  /* ---------------------------------------------------------------- */
  /* String conversions                                               */
  decimal64 * decimal64FromString(decimal64 *, const char *, decContext *);
  char * decimal64ToString(const decimal64 *, char *);
  char * decimal64ToEngString(const decimal64 *, char *);

  /* decNumber conversions                                            */
  decimal64 * decimal64FromNumber(decimal64 *, const decNumber *,
                                  decContext *);
  decNumber * decimal64ToNumber(const decimal64 *, decNumber *);

  /* Format-dependent utilities                                       */
  uint32_t    decimal64IsCanonical(const decimal64 *);
  decimal64 * decimal64Canonical(decimal64 *, const decimal64 *);

#endif