big-rat/lib/num-to-bn.js

A big integer rational number

'use strict'

var BN = require('bn.js')
var db = require('double-bits')

module.exports = num2bn

function num2bn(x) {
  var e = db.exponent(x)
  if(e < 52) {
    return new BN(x)
  } else {
    return (new BN(x * Math.pow(2, 52-e))).ushln(e-52)
  }
}