error[E0381]: use of possibly uninitialized variable: `x`
  --> $DIR/asm-out-read-uninit.rs:25:43
   |
LL |         asm!("mov $1, $0" : "=r"(x) : "r"(x));
   |                                           ^ use of possibly uninitialized `x`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0381`.