Fix big_int_or and big_int_xor

This commit is contained in:
gingerBill
2019-11-10 20:06:04 +00:00
parent 8da8301b09
commit 33d05a07de

View File

@@ -1248,15 +1248,15 @@ void big_int_xor(BigInt *dst, BigInt const *x, BigInt const *y) {
x = y;
y = tmp;
}
// x ^ (-y) == x ^ ~(y-1) == ~(x ^ (y-1)) == -((x ^ (y-1)) + 1)
dst->neg = false;
BigInt y1 = big_int_make_abs(y);
big_int_sub_eq(&y1, &BIG_INT_ONE);
big_int__xor_abs(dst, x, &y1);
big_int_add_eq(dst, &BIG_INT_ONE);
dst->neg = true;
if (y->neg) {
// x ^ (-y) == x ^ ~(y-1) == ~(x ^ (y-1)) == -((x ^ (y-1)) + 1)
BigInt y1 = big_int_make_abs(y);
big_int_sub_eq(&y1, &BIG_INT_ONE);
big_int__xor_abs(dst, x, &y1);
big_int_add_eq(dst, &BIG_INT_ONE);
dst->neg = true;
}
return;
}
@@ -1316,13 +1316,15 @@ void big_int_or(BigInt *dst, BigInt const *x, BigInt const *y) {
x = y;
y = tmp;
}
// x | (-y) == x | ~(y-1) == ~((y-1) &~ x) == -(~((y-1) &~ x) + 1)
BigInt y1 = big_int_make_abs(y);
big_int_sub_eq(&y1, &BIG_INT_ONE);
big_int__and_not_abs(dst, &y1, x);
big_int_add_eq(dst, &BIG_INT_ONE);
dst->neg = true;
dst->neg = false;
if (y->neg) {
// x | (-y) == x | ~(y-1) == ~((y-1) &~ x) == -(~((y-1) &~ x) + 1)
BigInt y1 = big_int_make_abs(y);
big_int_sub_eq(&y1, &BIG_INT_ONE);
big_int__and_not_abs(dst, &y1, x);
big_int_add_eq(dst, &BIG_INT_ONE);
dst->neg = true;
}
return;
}