(**************************************************************************)
(*     Sail                                                               *)
(*                                                                        *)
(*  Copyright (c) 2013-2017                                               *)
(*    Kathyrn Gray                                                        *)
(*    Shaked Flur                                                         *)
(*    Stephen Kell                                                        *)
(*    Gabriel Kerneis                                                     *)
(*    Robert Norton-Wright                                                *)
(*    Christopher Pulte                                                   *)
(*    Peter Sewell                                                        *)
(*    Alasdair Armstrong                                                  *)
(*    Brian Campbell                                                      *)
(*    Thomas Bauereiss                                                    *)
(*    Anthony Fox                                                         *)
(*    Jon French                                                          *)
(*    Dominic Mulligan                                                    *)
(*    Stephen Kell                                                        *)
(*    Mark Wassell                                                        *)
(*                                                                        *)
(*  All rights reserved.                                                  *)
(*                                                                        *)
(*  This software was developed by the University of Cambridge Computer   *)
(*  Laboratory as part of the Rigorous Engineering of Mainstream Systems  *)
(*  (REMS) project, funded by EPSRC grant EP/K008528/1.                   *)
(*                                                                        *)
(*  Redistribution and use in source and binary forms, with or without    *)
(*  modification, are permitted provided that the following conditions    *)
(*  are met:                                                              *)
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(*     notice, this list of conditions and the following disclaimer.      *)
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(*     notice, this list of conditions and the following disclaimer in    *)
(*     the documentation and/or other materials provided with the         *)
(*     distribution.                                                      *)
(*                                                                        *)
(*  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''    *)
(*  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED     *)
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(*  PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR   *)
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(*  SUCH DAMAGE.                                                          *)
(**************************************************************************)

open Array
open Jib_util

(** A mutable array based graph type, with nodes indexed by integers. *)
type 'a array_graph

(** Create an empty array_graph, specifying the initial size of the
   underlying array. *)
val make : initial_size:int -> unit -> 'a array_graph

module IntSet : Set.S with type elt = int

val get_cond : 'a array_graph -> int -> Jib.cval

val get_vertex : 'a array_graph -> int -> ('a * IntSet.t * IntSet.t) option

val iter_graph : ('a -> IntSet.t -> IntSet.t -> unit) -> 'a array_graph -> unit

(** Add a vertex to a graph, returning the index of the inserted
   vertex. If the number of vertices exceeds the size of the
   underlying array, then it is dynamically resized. *)
val add_vertex : 'a -> 'a array_graph -> int

(** Add an edge between two existing vertices. Raises Invalid_argument
   if either of the vertices do not exist. *)
val add_edge : int -> int -> 'a array_graph -> unit

exception Not_a_DAG of int

val topsort : 'a array_graph -> int list

type terminator =
  | T_undefined of Jib.ctyp
  | T_match_failure
  | T_end of Jib.name
  | T_goto of string
  | T_jump of int * string
  | T_label of string
  | T_none

type cf_node =
  | CF_label of string
  | CF_block of Jib.instr list * terminator
  | CF_guard of int
  | CF_start of Jib.ctyp NameMap.t

val control_flow_graph : Jib.instr list -> int * int list * ('a list * cf_node) array_graph

(** [immediate_dominators graph root] will calculate the immediate
   dominators for a control flow graph with a specified root node. *)
val immediate_dominators : 'a array_graph -> int -> int array

type ssa_elem =
  | Phi of Jib.name * Jib.ctyp * Jib.name list
  | Pi of Jib.cval list

(** Convert a list of instructions into SSA form *)
val ssa : Jib.instr list -> int * (ssa_elem list * cf_node) array_graph

(** Output the control-flow graph in graphviz format for
   debugging. Can use 'dot -Tpng X.gv -o X.png' to generate a png
   image of the graph. *)
val make_dot : out_channel -> (ssa_elem list * cf_node) array_graph -> unit

val make_dominators_dot : out_channel -> int array -> (ssa_elem list * cf_node) array_graph -> unit