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Fix big_int_or and big_int_xor

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gingerBill
2019-11-10 20:06:04 +00:00
parent 8da8301b09
commit 33d05a07de
1 changed files with 17 additions and 15 deletions
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src/big_int.cpp
+17 -15
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@@ -1248,15 +1248,15 @@ void big_int_xor(BigInt *dst, BigInt const *x, BigInt const *y) {
x = y; x = y;
y = tmp; y = tmp;
} }
// x ^ (-y) == x ^ ~(y-1) == ~(x ^ (y-1)) == -((x ^ (y-1)) + 1)
dst->neg = false; dst->neg = false;
BigInt y1 = big_int_make_abs(y); if (y->neg) {
big_int_sub_eq(&y1, &BIG_INT_ONE); // x ^ (-y) == x ^ ~(y-1) == ~(x ^ (y-1)) == -((x ^ (y-1)) + 1)
big_int__xor_abs(dst, x, &y1); BigInt y1 = big_int_make_abs(y);
big_int_add_eq(dst, &BIG_INT_ONE); big_int_sub_eq(&y1, &BIG_INT_ONE);
dst->neg = true; big_int__xor_abs(dst, x, &y1);
big_int_add_eq(dst, &BIG_INT_ONE);
dst->neg = true;
}
return; return;
} }
@@ -1316,13 +1316,15 @@ void big_int_or(BigInt *dst, BigInt const *x, BigInt const *y) {
x = y; x = y;
y = tmp; y = tmp;
} }
dst->neg = false;
// x | (-y) == x | ~(y-1) == ~((y-1) &~ x) == -(~((y-1) &~ x) + 1) if (y->neg) {
BigInt y1 = big_int_make_abs(y); // x | (-y) == x | ~(y-1) == ~((y-1) &~ x) == -(~((y-1) &~ x) + 1)
big_int_sub_eq(&y1, &BIG_INT_ONE); BigInt y1 = big_int_make_abs(y);
big_int__and_not_abs(dst, &y1, x); big_int_sub_eq(&y1, &BIG_INT_ONE);
big_int_add_eq(dst, &BIG_INT_ONE); big_int__and_not_abs(dst, &y1, x);
dst->neg = true; big_int_add_eq(dst, &BIG_INT_ONE);
dst->neg = true;
}
return; return;
} }