Files
cryptonum/src/unsigned/mul.rs

97 lines
2.7 KiB
Rust

pub fn multiply(dest: &mut [u64], left: &[u64], right: &[u64])
{
let len = right.len();
assert_eq!(left.len(), len, "Uneven argument lengths in multiply");
assert_eq!(dest.len(), len*2, "Bad destination size in multiply");
for i in 0..len {
let mut carry = 0;
for j in 0..len {
let old = dest[i+j] as u128;
let l128 = left[j] as u128;
let r128 = right[i] as u128;
let uv = old + (l128 * r128) + carry;
dest[i+j] = uv as u64;
carry = uv >> 64;
}
dest[i+len] = carry as u64;
}
}
macro_rules! multiply_impls {
($name: ident, $dbl: ident) => {
impl Mul<$name> for $name {
type Output = $dbl;
fn mul(self, rhs: $name) -> $dbl {
let mut res = $dbl::zero();
multiply(&mut res.value, &self.value, &rhs.value);
res
}
}
impl<'a> Mul<$name> for &'a $name {
type Output = $dbl;
fn mul(self, rhs: $name) -> $dbl {
let mut res = $dbl::zero();
multiply(&mut res.value, &self.value, &rhs.value);
res
}
}
impl<'a> Mul<&'a $name> for $name {
type Output = $dbl;
fn mul(self, rhs: &$name) -> $dbl {
let mut res = $dbl::zero();
multiply(&mut res.value, &self.value, &rhs.value);
res
}
}
impl<'a,'b> Mul<&'a $name> for &'b $name {
type Output = $dbl;
fn mul(self, rhs: &$name) -> $dbl {
let mut res = $dbl::zero();
multiply(&mut res.value, &self.value, &rhs.value);
res
}
}
};
}
#[cfg(test)]
macro_rules! generate_mul_tests
{
($name: ident, $lname: ident, $dbl: ident) => {
#[test]
fn $lname() {
generate_mul_tests!(body $name, $lname, $dbl);
}
};
(ignore $name: ident, $lname: ident, $dbl: ident) => {
#[test]
#[ignore]
fn $lname() {
generate_mul_tests!(body $name, $lname, $dbl);
}
};
(body $name: ident, $lname: ident, $dbl: ident) => {
let fname = format!("testdata/mul/{}.tests", stringify!($name));
run_test(fname.to_string(), 3, |case| {
let (neg0, abytes) = case.get("a").unwrap();
let (neg1, bbytes) = case.get("b").unwrap();
let (neg2, cbytes) = case.get("c").unwrap();
assert!(!neg0 && !neg1 && !neg2);
let a = $name::from_bytes(abytes);
let b = $name::from_bytes(bbytes);
let c = $dbl::from_bytes(cbytes);
assert_eq!(c, &a * &b);
});
};
}