/*  smmsize.cpp  by K.Tsuru  */
/***************
SNManager class
****************/
#ifndef SN_H
#include "sn.h"
#endif

uint SNManager::effFigures = defaultEffFig; //number of effective figures specified by user
uint SNManager::hidden = defaultHidden;     //number of hidden figures
uint SNManager::maxArraySize = defaultMaxArraySize;
uint SNManager::maxSize[SNManager::NUMBER_TYPE];
bool SNManager::reduceMaxSize = ENABLE;
void SNManager::SetMaxArraySize(uint s){
    if(s <= defaultMaxArraySize) return;    // do nothing
    maxArraySize = ceilpow2(s);
    SetMaxSize();
}
// function ID = 002
/**************************************************************************
enum declared in "snum.h"
number type SNumber::type;
lower 1st bit:integer, 2nd bit:decimal, 3rd bit:BRADIX(binary radix)
UNKNOWN is used in StringToNumber class.
enum NumberType { MIN_SIZE = 0, INTEGER = 1, REAL = 2, DEC_RDX = 3,
    BIN_RDX = 4, BIN_INT = 5, BIN_DEC = 6, NUMBER_TYPE = 7, UNKNOWN = 8};
**************************************************************************/
void SNManager::SetMaxSize(){
    maxSize[MIN_SIZE]= minArraySize;
    maxSize[DEC_INT] = maxArraySize;
    maxSize[ REAL  ] = SNEffFig(REAL) +Hidden()+ 1u;
    maxSize[DEC_RDX] = (uint)DRADIX;
    maxSize[BIN_RDX] = (uint)BRADIX;
#ifndef NDEBUG
assert(maxSize[REAL] > minArraySize);
#endif
    double s = (double)DFIGURES*(double)maxArraySize/log10((double)BRADIX)+1.0; // ver.2.17
    maxSize[BIN_INT] = (uint)s;
    maxSize[BIN_DEC] = SNEffFig(BIN_DEC) +Hidden()+ 1u;
}

//function ID = 003
//number of effective figures excluding figure[0]
uint SNManager::SNEffFig(NumberType tp){
#ifndef NDEBUG
assert(tp & REAL);
#endif
    static uint fig[2] = {0 , 0};
    uint f = effFigures;//number of effective figures specified by user

    if(fig[0] != f){    //evaluate again
        fig[0] = f;
//Testing in 1/3.0 = 0.33333... the justice has been confirmed.
        f = uint( (double)f*(double)DFIGURES/log10((double)BRADIX) )+1u; // ver.2.17
        if( (f+Hidden()+1) & 1 ) f++;   // f+hidden+1 = even
        fig[1] = f;
    }
    return (tp == REAL) ? fig[0] : fig[1];
}
// function ID = 007
/*******************************************************************************
Provides the number of hidden figures when the number of effective figures
"eff_fig" is given.
b = 9, m = 512, 1/512 = 0.2% or 8
At least two figures are necessary in the judgement of convergence in Newton's
method.
*********************************************************************************/
uint SNManager::HiddenSize(uint eff_fig){
    uint b = 9, m = 1 << (b+1), h;
    if(eff_fig < m) h = 2u;
    else h = eff_fig >> b;
    return min(h, 8u);
}