src/test/codegen/asm-multiple-options.rs

   1 // compile-flags: -O
   2 // only-x86_64
   3
   4 #![crate_type = "rlib"]
   5 #![feature(asm)]
   6
   7 // CHECK-LABEL: @pure
   8 // CHECK-NOT: asm
   9 // CHECK: ret void
  10 #[no_mangle]
  11 pub unsafe fn pure(x: i32) {
  12     let y: i32;
  13     asm!("", out("ax") y, in("bx") x, options(pure), options(nomem));
  14 }
  15
  16 pub static mut VAR: i32 = 0;
  17 pub static mut DUMMY_OUTPUT: i32 = 0;
  18
  19 // CHECK-LABEL: @readonly
  20 // CHECK: call i32 asm
  21 // CHECK: ret i32 1
  22 #[no_mangle]
  23 pub unsafe fn readonly() -> i32 {
  24     VAR = 1;
  25     asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(readonly));
  26     VAR
  27 }
  28
  29 // CHECK-LABEL: @nomem
  30 // CHECK-NOT: store
  31 // CHECK: call i32 asm
  32 // CHECK: store
  33 // CHECK: ret i32 2
  34 #[no_mangle]
  35 pub unsafe fn nomem() -> i32 {
  36     VAR = 1;
  37     asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(nomem));
  38     VAR = 2;
  39     VAR
  40 }
  41
  42 // CHECK-LABEL: @not_nomem
  43 // CHECK: store
  44 // CHECK: call i32 asm
  45 // CHECK: store
  46 // CHECK: ret i32 2
  47 #[no_mangle]
  48 pub unsafe fn not_nomem() -> i32 {
  49     VAR = 1;
  50     asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(readonly));
  51     VAR = 2;
  52     VAR
  53 }