// vim: filetype=c:tabstop=4:ai:expandtab
// SPDX-License-Identifier: ICU
// scspell-id: ca5518dc-f62c-11ec-9785-80ee73e9b8e7
/* ------------------------------------------------------------------ */
/* Decimal Number arithmetic module header                            */
/* ------------------------------------------------------------------ */
/* Copyright (c) IBM Corporation, 2000, 2010.  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(DECNUMBER)
# define DECNUMBER
# define DECNAME     "decNumber"                        /* Short name */
# define DECFULLNAME "Decimal Number Module"          /* Verbose name */
# define DECAUTHOR   "Mike Cowlishaw"                 /* Who to blame */

# if !defined(DECCONTEXT)
#  include "decContext.h"
# endif

  /* Bit settings for decNumber.bits                                  */
# define DECNEG    0x80      /* Sign; 1=negative, 0=positive or zero  */
# define DECINF    0x40      /* 1=Infinity                            */
# define DECNAN    0x20      /* 1=NaN                                 */
# define DECSNAN   0x10      /* 1=sNaN                                */
  /* The remaining bits are reserved; they must be 0                  */
# define DECSPECIAL (DECINF|DECNAN|DECSNAN)  /* any special value     */

  /* Define the decNumber data structure.  The size and shape of the  */
  /* units array in the structure is determined by the following      */
  /* constant.  This must not be changed without recompiling the      */
  /* decNumber library modules. */

  //#define DECDPUN 3         /* DECimal Digits Per UNit [must be >0  */
# define DECDPUN 8            /* DECimal Digits Per UNit [must be >0  */
                              /* and <10; 3 or powers of 2 are best]. */

  /* DECNUMDIGITS is the default number of digits that can be held in */
  /* the structure.  If undefined, 1 is assumed and it is assumed     */
  /* that the structure will be immediately followed by extra space,  */
  /* as required.  DECNUMDIGITS is always >0.                         */
# if !defined(DECNUMDIGITS)
#  define DECNUMDIGITS 1
# endif

  /* The size (integer data type) of each unit is determined by the   */
  /* number of digits it will hold.                                   */
# if DECDPUN<=2
#  define decNumberUnit uint8_t
# elif DECDPUN<=4
#  define decNumberUnit uint16_t
# else
#  define decNumberUnit uint32_t
# endif
  /* The number of units needed is ceil(DECNUMDIGITS/DECDPUN)         */
# define DECNUMUNITS ((DECNUMDIGITS+DECDPUN-1)/DECDPUN)

  /* The data structure... */
  typedef struct {
    int32_t digits;      /* Count of digits in the coefficient; >0    */
    int32_t exponent;    /* Unadjusted exponent, unbiased, in         */
                         /* range: -1999999997 through 999999999      */
    uint8_t bits;        /* Indicator bits (see above)                */
                         /* Coefficient, from least significant unit  */
    decNumberUnit lsu[DECNUMUNITS];
    } decNumber;

  /* Notes:                                                           */
  /* 1. If digits is > DECDPUN then there will one or more            */
  /*    decNumberUnits immediately following the first element of lsu.*/
  /*    These contain the remaining (more significant) digits of the  */
  /*    number, and may be in the lsu array, or may be guaranteed by  */
  /*    some other mechanism (such as being contained in another      */
  /*    structure, or being overlaid on dynamically allocated         */
  /*    storage).                                                     */
  /*                                                                  */
  /*    Each integer of the coefficient (except potentially the last) */
  /*    contains DECDPUN digits (e.g., a value in the range 0 through */
  /*    99999999 if DECDPUN is 8, or 0 through 999 if DECDPUN is 3).  */
  /*                                                                  */
  /* 2. A decNumber converted to a string may need up to digits+14    */
  /*    characters.  The worst cases (non-exponential and exponential */
  /*    formats) are -0.00000{9...}# and -9.{9...}E+999999999#        */
  /*    (where # is '\0')                                             */

  /* ---------------------------------------------------------------- */
  /* decNumber public functions and macros                            */
  /* ---------------------------------------------------------------- */
  /* Conversions                                                      */
  decNumber * decNumberFromInt32(decNumber *, int32_t);
  decNumber * decNumberFromUInt32(decNumber *, uint32_t);
  decNumber * decNumberFromString(decNumber *, const char *, decContext *);
  char      * decNumberToString(const decNumber *, char *);
  char      * decNumberToEngString(const decNumber *, char *);
  uint32_t    decNumberToUInt32(const decNumber *, decContext *);
  int32_t     decNumberToInt32(const decNumber *, decContext *);
  uint8_t   * decNumberGetBCD(const decNumber *, uint8_t *);
  decNumber * decNumberSetBCD(decNumber *, const uint8_t *, uint32_t);

  /* Operators and elementary functions                               */
  decNumber * decNumberAbs(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberAdd(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberAnd(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberCompare(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberCompareSignal(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberCompareTotal(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberCompareTotalMag(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberDivide(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberDivideInteger(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberExp(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberFMA(decNumber *, const decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberInvert(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberLn(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberLogB(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberLog10(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberMax(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberMaxMag(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberMin(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberMinMag(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberMinus(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberMultiply(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberNormalize(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberOr(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberPlus(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberPower(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberQuantize(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberReduce(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberRemainder(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberRemainderNear(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberRescale(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberRotate(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberSameQuantum(decNumber *, const decNumber *, const decNumber *);
  decNumber * decNumberScaleB(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberShift(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberSquareRoot(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberSubtract(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber * decNumberToIntegralExact(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberToIntegralValue(decNumber *, const decNumber *, decContext *);
  decNumber * decNumberXor(decNumber *, const decNumber *, const decNumber *, decContext *);

  /* Utilities                                                        */
  enum decClass decNumberClass(const decNumber *, decContext *);
  const char * decNumberClassToString(enum decClass);
  decNumber  * decNumberCopy(decNumber *, const decNumber *);
  decNumber  * decNumberCopyAbs(decNumber *, const decNumber *);
  decNumber  * decNumberCopyNegate(decNumber *, const decNumber *);
  decNumber  * decNumberCopySign(decNumber *, const decNumber *, const decNumber *);
  decNumber  * decNumberNextMinus(decNumber *, const decNumber *, decContext *);
  decNumber  * decNumberNextPlus(decNumber *, const decNumber *, decContext *);
  decNumber  * decNumberNextToward(decNumber *, const decNumber *, const decNumber *, decContext *);
  decNumber  * decNumberTrim(decNumber *);
  const char * decNumberVersion(void);
  decNumber  * decNumberZero(decNumber *);

  /* Functions for testing decNumbers (normality depends on context)  */
  int32_t decNumberIsNormal(const decNumber *, decContext *);
  int32_t decNumberIsSubnormal(const decNumber *, decContext *);

  /* Macros for testing decNumber *dn                                 */
# define decNumberIsCanonical(dn) (1)   /* All decNumbers are saintly */
# define decNumberIsFinite(dn)    (((dn)->bits&DECSPECIAL)==0)
# define decNumberIsInfinite(dn)  (((dn)->bits&DECINF)!=0)
# define decNumberIsNaN(dn)       (((dn)->bits&(DECNAN|DECSNAN))!=0)
# define decNumberIsNegative(dn)  (((dn)->bits&DECNEG)!=0)
# define decNumberIsQNaN(dn)      (((dn)->bits&(DECNAN))!=0)
# define decNumberIsSNaN(dn)      (((dn)->bits&(DECSNAN))!=0)
# define decNumberIsSpecial(dn)   (((dn)->bits&DECSPECIAL)!=0)
# define decNumberIsZero(dn)      (*(dn)->lsu==0 \
                                    && (dn)->digits==1 \
                                    && (((dn)->bits&DECSPECIAL)==0))
# define decNumberRadix(dn)       (10)

#endif
