/*  sxmsetdb.cpp  by K.Tsuru  */
// function ID = 501    BRADIX
#ifndef SN_H
#include "sn.h"
#endif
/*************************************************************
SDecimal class
Provides a radix conversion
double ---> BRADIX
Used in the substitution of double type including long type.
*************************************************************/
void SDecimal::SetXDouble(double d){
    if(d == 0.0){
        SetZero();  return;
    }
/***************************************************************************
A finite binary decimal such as ldexp(1.5, -400) = 1.5*2^(-400) must be
converted exactly.If this is treated in the decimal radix(DRADIX) an
inacurate value is supplied because of taiking into account fifteen
effective figures only.On the other hand if an infinite binary decimal such
as 0.1 are converted to a binary decimal in 53 bits it may be contrary to
user's expectations.In this case it converts once the value into DRADIX,
next into BRADIX.
A decimal ldexp(f, -400) whose f has more than 30 bits cannot be converted
exactly? It is difficult to judge whether it must be converted into infinite
or finite decimal.
***************************************************************************/
    uint sz;
//Convert |d| into a value with binary radix(BRADIX). This can be performed
//exactly for any value.
    int bfig = DOUBLE_BITS/BRADIX_BITS; // = 53bits/15 = 3.5figures
    int f = doubleToBinDec(fabs(d), figure, &sz);

    if(f < 0) SetError(OVERFLOW_ERR, "SetXDouble",501);
    if(f < bfig){//within two figures in BRADIX(30bits) for safety.
    // |d| = I.abcd efgh 0000 abcd efgh .... can be existent.
        aTail = 0;
        sz = min(sz, MaxSize());
        while( (figure(aTail)== 0) && (aTail < sz) ) aTail++;
    // d is very small and can be regarded as zero within present accuracy.
        if(aTail == sz){
            SetZero();  return;
        }
        aHead = sz-1u;  while(figure(aHead)== 0) aHead--;
        SetSign(d);
        return;
    }
//Here it may be an infinite decimal in BRADIX.
    SDouble a(d);           //convert into DRADIX
    SDecimal tmp;   // Changes called by object since version 2.20
    *this = tmp.ConvToBin(a);   //convert into BRADIX
}