Words

Split a double-precision floating-point number into a higher order word and a lower order word.

Usage

var toWords = require( '@stdlib/number/float64/base/to-words' );

toWords( [out,] x )

Splits a double-precision floating-point number into a higher order word (unsigned 32-bit integer) and a lower order word (unsigned 32-bit integer).

var w = toWords( 3.14e201 );
// returns [ 1774486211, 2479577218 ]

By default, the function returns an array containing two elements: a higher order word and a lower order word. The lower order word contains the less significant bits, while the higher order word contains the more significant bits and includes the exponent and sign.

var w = toWords( 3.14e201 );
// returns [ 1774486211, 2479577218 ]

var high = w[ 0 ];
// returns 1774486211

var low = w[ 1 ];
// returns 2479577218

To avoid unnecessary memory allocation, the function supports providing an output (destination) object.

var Uint32Array = require( '@stdlib/array/uint32' );

var out = new Uint32Array( 2 );

var w = toWords( out, 3.14e201 );
// returns <Uint32Array>[ 1774486211, 2479577218 ]

var bool = ( w === out );
// returns true

Examples

var floor = require( '@stdlib/math/base/special/floor' );
var randu = require( '@stdlib/random/base/randu' );
var pow = require( '@stdlib/math/base/special/pow' );
var toWords = require( '@stdlib/number/float64/base/to-words' );

var frac;
var exp;
var w;
var x;
var i;

// Generate random numbers and split into words...
for ( i = 0; i < 100; i++ ) {
    frac = randu() * 10.0;
    exp = -floor( randu()*324.0 );
    x = frac * pow( 10.0, exp );
    w = toWords( x );
    console.log( 'x: %d. higher: %d. lower: %d.', x, w[ 0 ], w[ 1 ] );
}