/**
 * Returns 0 if a === b, a +tive value if a > b or a negative value if a < b.
 * 
 * @param x a double-double precision floating point number
 * @param y another double-double precision floating point number
 */
function ddCompare(x: number[], y: number[]) {
    //return ddDiffDd(x,y)[1];
    
    const xl = x[0];
    const xh = x[1];
    const yl = y[0];
    const yh = y[1];

    //const [sl,sh] = twoSum(xh,yh);
    const sh = xh - yh; const _1 = sh - xh; const sl = (xh - (sh - _1)) + (-yh - _1);
    //const [tl,th] = twoSum(xl,yl);
    const th = xl - yl; const _2 = th - xl; const tl = (xl - (th - _2)) + (-yl - _2);
    const c = sl + th;
    //const [vl,vh] = fastTwoSum(sh,c)
    const vh = sh + c; const vl = c - (vh - sh);
    const w = tl + vl
    //const [zl,zh] = fastTwoSum(vh,w)
    const zh = vh + w; 

    return zh;
}


export { ddCompare }