(* ssa.sml
 *
 * COPYRIGHT (c) 2010 The Diderot Project (http://diderot.cs.uchicago.edu)
 * All rights reserved.
 *)

structure SSA =
  struct

    datatype var = V of {
	name : string
      }

    datatype block = BLK of {
	id : label,
	preds : block list ref,
	phi : (var * var list) list ref,
	stms : stm list ref,
	xfer : transfer ref
      }

    and stm
      = ASSIGN of var * exp

    and xfer
      = GOTO of label			(* unconditional transfer *)
      | COND of var * label * label	(* conditional transfer *)
      | DIE				(* actor termination *)
      | STABILIZE			(* actor stabilization node *)
      | EXIT				(* exit node *)

    and exp
      = VAR of exp

  end