rotl.rs
| #![feature(asm, macro_rules)] | |
| use std::mem; | |
| fn rotl(val: u64, shift: u8) -> u64 { | |
| let sz = mem::size_of_val(&val); | |
| (val << shift) | (val >> (sz * 8 - shift as uint)) | |
| } | |
| macro_rules! rotl( | |
| ($val: expr, $shift: expr) => ( | |
| { | |
| let val = $val; | |
| let shift = $shift; | |
| let sz = mem::size_of_val(&val); | |
| (val << shift) | (val >> (sz * 8 - shift as uint)) | |
| } | |
| ); | |
| ) | |
| fn asm_rotl(mut x: u64, a: u8) -> u64 { | |
| unsafe { | |
| asm!("rolq $2, $0" | |
| : "=r"(x) | |
| : "0"(x), "{cl}"(a)); | |
| } | |
| x | |
| } | |
| fn main() { | |
| println!("rotl(32, 2) - {}", rotl(32, 2)); | |
| println!("rotl!(32, 2) - {}", rotl!(32, 2)); | |
| println!("asm_rotl(32, 2) - {}", asm_rotl(32, 2)); | |
| } |