^

/*
 * call-seq:
 *     big ^ numeric   =>  integer
 *
 * Performs bitwise +exclusive or+ between _big_ and _numeric_.
 */

VALUE
rb_big_xor(xx, yy)
    VALUE xx, yy;
{
    volatile VALUE x, y;
    VALUE z;
    BDIGIT *ds1, *ds2, *zds;
    long i, l1, l2;
    char sign;

    x = xx;
    y = rb_to_int(yy);
    if (FIXNUM_P(y)) {
        y = rb_int2big(FIX2LONG(y));
    }
    if (!RBIGNUM(y)->sign) {
        y = rb_big_clone(y);
        get2comp(y);
    }
    if (!RBIGNUM(x)->sign) {
        x = rb_big_clone(x);
        get2comp(x);
    }
    if (RBIGNUM(x)->len > RBIGNUM(y)->len) {
        l1 = RBIGNUM(y)->len;
        l2 = RBIGNUM(x)->len;
        ds1 = BDIGITS(y);
        ds2 = BDIGITS(x);
        sign = RBIGNUM(y)->sign;
    }
    else {
        l1 = RBIGNUM(x)->len;
        l2 = RBIGNUM(y)->len;
        ds1 = BDIGITS(x);
        ds2 = BDIGITS(y);
        sign = RBIGNUM(x)->sign;
    }
    RBIGNUM(x)->sign = RBIGNUM(x)->sign?1:0;
    RBIGNUM(y)->sign = RBIGNUM(y)->sign?1:0;
    z = bignew(l2, !(RBIGNUM(x)->sign ^ RBIGNUM(y)->sign));
    zds = BDIGITS(z);

    for (i=0; i<l1; i++) {
        zds[i] = ds1[i] ^ ds2[i];
    }
    for (; i<l2; i++) {
        zds[i] = sign?ds2[i]:~ds2[i];
    }
    if (!RBIGNUM(z)->sign) get2comp(z);

    return bignorm(z);
}