function float64ToInt64Bytes( x ) {
	var bytes;
	var view;
	var hi;
	var lo;

	bytes = new Uint8Array( 8 );
	if ( x === 0 ) {
		return bytes;
	}
	// Get the low 32-bit word:
	lo = (x&LOW_MASK)>>>0;

	// Get the high 32-bit word:
	hi = floor( x/TWO_32 );

	// Insert the high and low words according to host byte order (endianness):
	view = new DataView( bytes.buffer );
	if ( IS_LITTLE_ENDIAN ) {
		view.setUint32( 0, lo, IS_LITTLE_ENDIAN );
		view.setUint32( 4, hi, IS_LITTLE_ENDIAN );
	} else {
		view.setUint32( 0, hi, IS_LITTLE_ENDIAN );
		view.setUint32( 4, lo, IS_LITTLE_ENDIAN );
	}
	return bytes;
}
Converts an integer-valued double-precision floating-point number to a signed 64-bit integer byte array according to host byte order (endianness).

## Notes

-   This function assumes that the input value is less than the maximum safe double-precision floating-point integer plus one (i.e., `2**53`).

@param {number} x - input value
@returns {Uint8Array} byte array

@example
var bytes = float64ToInt64Bytes( 1.0 );
// returns <Uint8Array>