/*  sifisadd.cpp  by K.Tsuru  */
// function ID = 421   BRADIX
/*************************************************
SInteger class
SInteger + unsigned short
It is used in SInteger ConvToBin(const SLong& m);
operator++
result = m+s  ( s < BRADIX)
**************************************************/
#ifndef SN_H
#include "sn.h"
#endif
void IsAdd(const SInteger& m, fType s, SInteger& result){
    if(s >= BRADIX) m.SetError(m.OUT_OF_RANGE, "IsAdd", 421);
    result = m;     // copy
    if(!s) return;
// result == m
    if(m.Sign(421)<0){
    // m + s = -(|m|-s)
        result.SetSign(1);  IsSub(result, s, result);   result.SetSign(-1);
        return;
    }
    result.figure[0] += s;  // result.figure[0] > 0
    if(result.figure[0] < BRADIX){  result.aTail = 0;   return; }

// normalize
    fType* rv = result.figure.Elements();
    fType u = rv[0] >> BRADIX_BITS;     // u > 0
    rv[0] &= BRADIX1;

    register uint i = 0;
    while(u && i < m.aHead){
        i++;
        u += rv[i];
        rv[i] = u & BRADIX1;
        u >>= BRADIX_BITS;
    }
    if(u){  // for carray.   i == m.aHead
        result.aHead++;
        result.Reserve(result.aHead);
        rv = result.figure.Elements();
        result.figure[result.aHead] = u;
    } else result.aHead = m.aHead;
#ifndef NDEBUG
result.figure(result.aHead);
#endif
    i = 0;
    while(!rv[i]) i++;
    result.aTail = i;
    if( 2u*(result.aHead+1) <= result.figure.size() ) result.DoCutDown();
}