mirror of
https://github.com/rust-lang/rust.git
synced 2024-10-30 14:01:51 +00:00
55 lines
1.0 KiB
Rust
55 lines
1.0 KiB
Rust
//@ compile-flags: -O
|
|
//@ only-x86_64
|
|
|
|
#![crate_type = "rlib"]
|
|
|
|
use std::arch::asm;
|
|
|
|
// CHECK-LABEL: @pure
|
|
// CHECK-NOT: asm
|
|
// CHECK: ret void
|
|
#[no_mangle]
|
|
pub unsafe fn pure(x: i32) {
|
|
let y: i32;
|
|
asm!("", out("ax") y, in("cx") x, options(pure), options(nomem));
|
|
}
|
|
|
|
pub static mut VAR: i32 = 0;
|
|
pub static mut DUMMY_OUTPUT: i32 = 0;
|
|
|
|
// CHECK-LABEL: @readonly
|
|
// CHECK: call i32 asm
|
|
// CHECK: ret i32 1
|
|
#[no_mangle]
|
|
pub unsafe fn readonly() -> i32 {
|
|
VAR = 1;
|
|
asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(readonly));
|
|
VAR
|
|
}
|
|
|
|
// CHECK-LABEL: @nomem
|
|
// CHECK-NOT: store
|
|
// CHECK: call i32 asm
|
|
// CHECK: store
|
|
// CHECK: ret i32 2
|
|
#[no_mangle]
|
|
pub unsafe fn nomem() -> i32 {
|
|
VAR = 1;
|
|
asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(nomem));
|
|
VAR = 2;
|
|
VAR
|
|
}
|
|
|
|
// CHECK-LABEL: @not_nomem
|
|
// CHECK: store
|
|
// CHECK: call i32 asm
|
|
// CHECK: store
|
|
// CHECK: ret i32 2
|
|
#[no_mangle]
|
|
pub unsafe fn not_nomem() -> i32 {
|
|
VAR = 1;
|
|
asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(readonly));
|
|
VAR = 2;
|
|
VAR
|
|
}
|