/*  sfmredc.cpp  by K.Tsuru  */
// function ID = 701  DRADIX
/*************************************
SFraction class
It provides the reduction of fraction.
**************************************/
#ifndef SN_H
#include "sn.h"
#endif

#if REDUCE_SIZE
static const uint initReduceSize = 512; //initial value of "reduceSize"
uint SFraction::reduceSize = initReduceSize;
bool SFraction::reduceStepByStep = true;

void SFraction::reduce(bool must){
#else
void SFraction::reduce(){
#endif

    if( !num.Sign(701) ){  SetZero();  return; }        //denominator=0
    if( num.IsOne() || den.IsOne() ) reduceDone = true; //denominator or numerator=1
    if( reduceDone == true ) return;

// reduceDone = FALSE
//To reduce as late as possible It divides by 2^b*R^r.
    if( !(num[0] % 2u) && !(den[0] % 2u) )  ReduceByPow2Rdx(num, den);
#if REDUCE_SIZE
    if( !must && ( max( num.Head(), den.Head() ) < ReduceSize() )) return;
#endif
//reduction
    SLong d = gcdL(num, den);   // d > 0
    num /= d;    den /= d;
    reduceDone = true;

#if REDUCE_SIZE
/*
When the calculation of large figures continues inspite of reduction,
it enlarges the value of "reduceSize".
*/
    uint rds = min(num.Head(), den.Head()) +1u;
    if(rds > ReduceSize()) SetReduceSize( min(4u*rds, num.MaxSize()) );
    else SetReduceSize(initReduceSize);
#endif
}