/*  sdcm2pi.cpp  by K.Tsuru  */
// function ID 3506  DRADIX, constant
/********************************
SDouble class
2/pi
Used in the reduction of an argument
of trigonometric functions.
*********************************/
#ifndef SN_H
#include "sn.h"
#endif

static SDouble* m2pi = NULL;    //keep in the static memory
static uint m2pi_size = 0;

void M2PiFree(){        //free memory of m2pi
    if(m2pi_size == 0) return;
    delete m2pi;        m2pi = NULL;        m2pi_size = 0;
}

/* 2/pi */
SDouble M2Pi(){
    uint ms = SNManager::SNMaxSize(SNManager::REAL);
    if(m2pi_size <  ms){
        if(m2pi == NULL) m2pi = new SDouble;

        SDouble pi2 = MPi2();       // pi/2
        *m2pi = DReciprocal(pi2);   // 2/pi
        m2pi_size = ms;
    }
    return *m2pi;
}