// 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 }