Field_ops_lib.Modulo_triple_pipeComputes (3 * x) mod p using an a modulo adder and a modulo double.
val hierarchical : 
  stages:int ->
  p:Z.t ->
  scope:Hardcaml.Scope.t ->
  clock:Hardcaml.Signal.t ->
  enable:Hardcaml.Signal.t ->
  Hardcaml.Signal.t ->
  Hardcaml.Signal.t