pub fn rotate_left(x: u64, shift: u32) -> u64 {
let shift = shift & 0x3F;
if shift == 0 {
return x;
}
(x << shift) | (x >> (64 - shift))
}
pub fn rotate_right(x: u64, shift: u32) -> u64 {
let shift = shift & 0x3F;
if shift == 0 {
return x;
}
(x << (64 - shift)) | (x >> shift)
}
#[cfg(test)]
pub mod tests {
use super::*;
#[test]
fn rotate() {
let x = 0x0123456789ABCDEF;
assert_eq!(rotate_left(x, 0), x);
assert_eq!(rotate_right(x, 0), x);
assert_eq!(rotate_left(x, 16), 0x456789ABCDEF0123);
assert_eq!(rotate_right(x, 16), 0xCDEF0123456789AB);
assert_eq!(rotate_left(x, 64), x);
assert_eq!(rotate_right(x, 64), x);
assert_eq!(rotate_left(x, 80), 0x456789ABCDEF0123);
assert_eq!(rotate_right(x, 80), 0xCDEF0123456789AB);
}
}