rust/tests/ui/intrinsics/intrinsic-assume.rs

// run-pass
#![feature(core_intrinsics)]

use std::intrinsics::assume;

unsafe fn f(x: i32) -> i32 {
    assume(x == 34);
    match x {
        34 => 42,
        _  => 30
    }
}

fn main() {
    let x = unsafe { f(34) };
    assert_eq!(x, 42);
}
Add `// run-pass` annotations to all the tests under `ui/run-pass/`. (I may have accidentally added it to some auxilliary crates as well; my emacs-macro-based methodology was pretty crude.) 2018-08-30 07:18:55 -05:00			`// run-pass`
Fallout in tests and docs from feature renamings 2015-06-10 15:33:52 -05:00			`#![feature(core_intrinsics)]`
Require feature attributes, and add them where necessary 2015-03-05 20:33:58 -06:00
Add assume intrinsic Adds an `assume` intrinsic that gets translated to llvm.assume. It is used on a boolean expression and allows the optimizer to assume that the expression is true. This implements #18051. 2014-10-15 18:44:44 -05:00			`use std::intrinsics::assume;`

			`unsafe fn f(x: i32) -> i32 {`
			`assume(x == 34);`
			`match x {`
			`34 => 42,`
			`_ => 30`
			`}`
			`}`

			`fn main() {`
			`let x = unsafe { f(34) };`
			`assert_eq!(x, 42);`
			`}`