tests/run-make-fulldeps/pgo-use/main.rs

   1 #[no_mangle]
   2 pub fn cold_function(c: u8) {
   3     println!("cold {}", c);
   4 }
   5
   6 #[no_mangle]
   7 pub fn hot_function(c: u8) {
   8     std::env::set_var(format!("var{}", c), format!("hot {}", c));
   9 }
  10
  11 fn main() {
  12     let arg = std::env::args().skip(1).next().unwrap();
  13
  14     for i in 0 .. 1000_000 {
  15         let some_value = arg.as_bytes()[i % arg.len()];
  16         if some_value == b'!' {
  17             // This branch is never taken at runtime
  18             cold_function(some_value);
  19         } else {
  20             hot_function(some_value);
  21         }
  22     }
  23 }