Files
cryptonum/src/unsigned/add.rs

136 lines
3.8 KiB
Rust

pub fn addition(dest: &mut [u64], src: &[u64])
{
assert_eq!(dest.len(), src.len() + 1);
let mut carry: u128 = 0;
for i in 0..src.len() {
let x128 = dest[i] as u128;
let y128 = src[i] as u128;
let z128 = x128 + y128 + carry;
dest[i] = z128 as u64;
carry = z128 >> 64;
}
dest[src.len()] = carry as u64;
}
pub fn unsafe_addition(dest: &mut [u64], src: &[u64], really_unsafe: bool)
{
assert_eq!(dest.len(), src.len());
let mut carry: u128 = 0;
for i in 0..src.len() {
let x128 = dest[i] as u128;
let y128 = src[i] as u128;
let z128 = x128 + y128 + carry;
dest[i] = z128 as u64;
carry = z128 >> 64;
}
if !really_unsafe {
assert_eq!(carry, 0, "Unsafe overflow in AddAssign");
}
}
macro_rules! addition_impls
{
($base: ident, $bigger: ident) => {
impl AddAssign<$base> for $base {
fn add_assign(&mut self, rhs: $base) {
unsafe_addition(&mut self.value, &rhs.value, false);
}
}
impl<'a> AddAssign<&'a $base> for $base {
fn add_assign(&mut self, rhs: &$base) {
unsafe_addition(&mut self.value, &rhs.value, false);
}
}
impl Add<$base> for $base {
type Output = $bigger;
fn add(self, rhs: $base) -> $bigger
{
let mut dest = $bigger::zero();
&dest.value[0..rhs.value.len()].copy_from_slice(&self.value);
addition(&mut dest.value, &rhs.value);
dest
}
}
impl<'a> Add<&'a $base> for $base {
type Output = $bigger;
fn add(self, rhs: &$base) -> $bigger
{
let mut dest = $bigger::zero();
&dest.value[0..rhs.value.len()].copy_from_slice(&self.value);
addition(&mut dest.value, &rhs.value);
dest
}
}
impl<'a> Add<$base> for &'a $base {
type Output = $bigger;
fn add(self, rhs: $base) -> $bigger
{
let mut dest = $bigger::zero();
&dest.value[0..rhs.value.len()].copy_from_slice(&self.value);
addition(&mut dest.value, &rhs.value);
dest
}
}
impl<'a,'b> Add<&'a $base> for &'b $base {
type Output = $bigger;
fn add(self, rhs: &$base) -> $bigger
{
let mut dest = $bigger::zero();
&dest.value[0..rhs.value.len()].copy_from_slice(&self.value);
addition(&mut dest.value, &rhs.value);
dest
}
}
}
}
#[cfg(test)]
macro_rules! generate_add_tests {
($name: ident, $lname: ident, $plus1: ident) => {
#[test]
fn $lname() {
generate_add_tests!(body $name, $lname, $plus1);
}
};
(ignore $name: ident, $lname: ident, $plus1: ident) => {
#[test]
#[ignore]
fn $lname() {
generate_add_tests!(body $name, $lname, $plus1);
}
};
(body $name: ident, $lname: ident, $plus1: ident) => {
let fname = build_test_path("add", stringify!($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 = $plus1::from_bytes(cbytes);
assert_eq!(c, &a + &b);
if c.value[c.value.len()-1] == 0 {
let mut aprime = a.clone();
aprime += b;
assert_eq!($name::from(c), aprime);
}
});
};
}