src/test/codegen/likely.rs

   1 // compile-flags: -C no-prepopulate-passes
   2
   3 #![crate_type = "lib"]
   4 #![feature(core_intrinsics)]
   5
   6 use std::intrinsics::{likely,unlikely};
   7
   8 #[no_mangle]
   9 pub fn check_likely(x: i32, y: i32) -> Option<i32> {
  10     unsafe {
  11         // CHECK: call i1 @llvm.expect.i1(i1 %{{.*}}, i1 true)
  12         if likely(x == y) {
  13             None
  14         } else {
  15             Some(x + y)
  16         }
  17     }
  18 }
  19
  20 #[no_mangle]
  21 pub fn check_unlikely(x: i32, y: i32) -> Option<i32> {
  22     unsafe {
  23         // CHECK: call i1 @llvm.expect.i1(i1 %{{.*}}, i1 false)
  24         if unlikely(x == y) {
  25             None
  26         } else {
  27             Some(x + y)
  28         }
  29     }
  30 }