src/test/codegen/try_identity.rs

   1 // compile-flags: -C no-prepopulate-passes -Z mir-opt-level=2
   2
   3 // Ensure that `x?` has no overhead on `Result<T, E>` due to identity `match`es in lowering.
   4 // This requires inlining to trigger the MIR optimizations in `SimplifyArmIdentity`.
   5
   6 #![crate_type = "lib"]
   7
   8 type R = Result<u64, i32>;
   9
  10 #[no_mangle]
  11 fn try_identity(x: R) -> R {
  12 // CHECK: start:
  13 // CHECK-NOT: br {{.*}}
  14 // CHECK ret void
  15     let y = x?;
  16     Ok(y)
  17 }