(module
  ;; recursive, more compact version
  (func $fac_f64 (export "fac_f64") (param f64) (result f64)
    get_local 0 f64.const 1 f64.lt
    if (result f64)
      f64.const 1
    else
      get_local 0
        get_local 0  f64.const 1  f64.sub
        call $fac_f64
      f64.mul
    end
  )
)