error[E0381]: use of possibly-uninitialized variable: `x`
  --> $DIR/llvm-asm-out-read-uninit.rs:23:48
   |
LL |         llvm_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`.