rust/tests/codegen/intrinsics/likely.rs

31 lines
637 B
Rust

//@ compile-flags: -C no-prepopulate-passes
#![crate_type = "lib"]
#![feature(core_intrinsics)]
use std::intrinsics::{likely,unlikely};
#[no_mangle]
pub fn check_likely(x: i32, y: i32) -> Option<i32> {
unsafe {
// CHECK: call i1 @llvm.expect.i1(i1 %{{.*}}, i1 true)
if likely(x == y) {
None
} else {
Some(x + y)
}
}
}
#[no_mangle]
pub fn check_unlikely(x: i32, y: i32) -> Option<i32> {
unsafe {
// CHECK: call i1 @llvm.expect.i1(i1 %{{.*}}, i1 false)
if unlikely(x == y) {
None
} else {
Some(x + y)
}
}
}