Function cswap

vmm/src/x25519.js:1224–1229

(p, q, b)

        M(p[3], e, h);
    }
    function cswap(p, q, b) {
        var i;
        for (i = 0; i < 4; i++) {
            sel25519(p[i], q[i], b);
        }
    }
    function pack(r, p) {
        var tx = gf(), ty = gf(), zi = gf();
        inv25519(zi, p[2]);