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// run-pass
#![feature(llvm_asm)]
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
fn read(ptr: &u32) -> u32 {
let out: u32;
unsafe {
llvm_asm!("mov $1, $0" : "=r" (out) : "*m" (ptr));
}
out
}
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
fn write(ptr: &mut u32, val: u32) {
unsafe {
llvm_asm!("mov $1, $0" : "=*m" (ptr) : "r" (val));
}
}
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
fn replace(ptr: &mut u32, val: u32) -> u32 {
let out: u32;
unsafe {
llvm_asm!("mov $0, $1; mov $2, $0" : "+*m" (ptr), "=&r" (out) : "r" (val));
}
out
}
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
pub fn main() {
let a = 1;
assert_eq!(read(&a), 1);
let mut b = 2;
write(&mut b, 3);
assert_eq!(b, 3);
let mut c = 4;
assert_eq!(replace(&mut c, 5), 4);
assert_eq!(c, 5);
}
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
pub fn main() {}
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