function gswap( N, x, strideX, offsetX, y, strideY, offsetY ) {
	var tmp;
	var ix;
	var iy;
	var ox;
	var oy;
	var m;
	var i;

	if ( N <= 0 ) {
		return y;
	}
	ox = arraylike2object( x );
	oy = arraylike2object( y );
	if ( ox.accessorProtocol || oy.accessorProtocol ) {
		accessors( N, ox, strideX, offsetX, oy, strideY, offsetY );
		return oy.data;
	}
	ix = offsetX;
	iy = offsetY;

	// Use unrolled loops if both strides are equal to `1`...
	if ( strideX === 1 && strideY === 1 ) {
		m = N % M;

		// If we have a remainder, run a clean-up loop...
		if ( m > 0 ) {
			for ( i = 0; i < m; i++ ) {
				tmp = x[ ix ];
				x[ ix ] = y[ iy ];
				y[ iy ] = tmp;
				ix += strideX;
				iy += strideY;
			}
		}
		if ( N < M ) {
			return y;
		}
		for ( i = m; i < N; i += M ) {
			tmp = x[ ix ];
			x[ ix ] = y[ iy ];
			y[ iy ] = tmp;

			tmp = x[ ix+1 ];
			x[ ix+1 ] = y[ iy+1 ];
			y[ iy+1 ] = tmp;

			tmp = x[ ix+2 ];
			x[ ix+2 ] = y[ iy+2 ];
			y[ iy+2 ] = tmp;

			ix += M;
			iy += M;
		}
		return y;
	}
	for ( i = 0; i < N; i++ ) {
		tmp = x[ ix ];
		x[ ix ] = y[ iy ];
		y[ iy ] = tmp;
		ix += strideX;
		iy += strideY;
	}
	return y;
}
Interchanges vectors `x` and `y`.

@param {PositiveInteger} N - number of indexed elements
@param {Collection} x - first input array
@param {integer} strideX - `x` stride length
@param {NonNegativeInteger} offsetX - starting `x` index
@param {Collection} y - second input array
@param {integer} strideY - `y` stride length
@param {NonNegativeInteger} offsetY - starting `y` index
@returns {Collection} `y`

@example
var x = [ 1.0, 2.0, 3.0, 4.0, 5.0 ];
var y = [ 6.0, 7.0, 8.0, 9.0, 10.0 ];

gswap( x.length, x, 1, 0, y, 1, 0 );
// x => [ 6.0, 7.0, 8.0, 9.0, 10.0 ]
// y => [ 1.0, 2.0, 3.0, 4.0, 5.0 ]