AssemblyScript switch-case

main.ts

export function test(c: u8): i32 {
  switch(c) {
    case 0:
      return 0
    case 1:
      return 1
    case 2:
      return 2
    case 3:
      return 3
    case 4:
      return 4
    default:
      return -1
  }
}

main.wat

(module
  (type $t0 (func (param i32) (result i32)))
  (type $t1 (func))
  (func $test (export "test") (type $t0) (param $p0 i32) (result i32)
    block $B0
      block $B1
        block $B2
          block $B3
            block $B4
              get_local $p0
              i32.const 255
              i32.and
              tee_local $p0
              if $I5
                get_local $p0
                i32.const 1
                i32.sub
                br_table $B4 $B3 $B2 $B1 $B0
              end
              i32.const 0
              return
            end
            i32.const 1
            return
          end
          i32.const 2
          return
        end
        i32.const 3
        return
      end
      i32.const 4
      return
    end
    i32.const -1)
  (func $f1 (type $t1)
    nop)
  (memory $memory (export "memory") 0))