(************************************************************************)
(*         *   The Coq Proof Assistant / The Coq Development Team       *)
(*  v      *   INRIA, CNRS and contributors - Copyright 1999-2018       *)
(* <O___,, *       (see CREDITS file for the list of authors)           *)
(*   \VV/  **************************************************************)
(*    //   *    This file is distributed under the terms of the         *)
(*         *     GNU Lesser General Public License Version 2.1          *)
(*         *     (see LICENSE file for the text of the license)         *)
(************************************************************************)

open CErrors
open Names
open Constr
open Declarations
open Util
open Nativevalues
open Nativeinstr
open Nativelambda
open Environ

[@@@ocaml.warning "-32-37"]

(** This file defines the mllambda code generation phase of the native
compiler. mllambda represents a fragment of ML, and can easily be printed
to OCaml code. *)

(** Local names **)

(* The first component is there for debugging purposes only *)
type lname = { lname : Name.t; luid : int }

let eq_lname ln1 ln2 =
  Int.equal ln1.luid ln2.luid

let dummy_lname = { lname = Anonymous; luid = -1 }

module LNord = 
  struct 
    type t = lname 
    let compare l1 l2 = l1.luid - l2.luid
  end
module LNmap = Map.Make(LNord)
module LNset = Set.Make(LNord)

let lname_ctr = ref (-1)

let fresh_lname n = 
  incr lname_ctr;
  { lname = n; luid = !lname_ctr }

(** Global names **)
type gname = 
  | Gind of string * inductive (* prefix, inductive name *)
  | Gconstruct of string * constructor (* prefix, constructor name *)
  | Gconstant of string * Constant.t (* prefix, constant name *)
  | Gproj of string * inductive * int (* prefix, inductive, index (start from 0) *)
  | Gcase of Label.t option * int
  | Gpred of Label.t option * int
  | Gfixtype of Label.t option * int
  | Gnorm of Label.t option * int
  | Gnormtbl of Label.t option * int
  | Ginternal of string
  | Grel of int
  | Gnamed of Id.t

let eq_gname gn1 gn2 =
  match gn1, gn2 with
  | Gind (s1, ind1), Gind (s2, ind2) ->
     String.equal s1 s2 && eq_ind ind1 ind2
  | Gconstruct (s1, c1), Gconstruct (s2, c2) ->
      String.equal s1 s2 && eq_constructor c1 c2
  | Gconstant (s1, c1), Gconstant (s2, c2) ->
      String.equal s1 s2 && Constant.equal c1 c2
  | Gproj (s1, ind1, i1), Gproj (s2, ind2, i2) ->
    String.equal s1 s2 && eq_ind ind1 ind2 && Int.equal i1 i2
  | Gcase (None, i1), Gcase (None, i2) -> Int.equal i1 i2
  | Gcase (Some l1, i1), Gcase (Some l2, i2) -> Int.equal i1 i2 && Label.equal l1 l2
  | Gpred (None, i1), Gpred (None, i2) -> Int.equal i1 i2
  | Gpred (Some l1, i1), Gpred (Some l2, i2) -> Int.equal i1 i2 && Label.equal l1 l2
  | Gfixtype (None, i1), Gfixtype (None, i2) -> Int.equal i1 i2
  | Gfixtype (Some l1, i1), Gfixtype (Some l2, i2) ->
      Int.equal i1 i2 && Label.equal l1 l2
  | Gnorm (None, i1), Gnorm (None, i2) -> Int.equal i1 i2
  | Gnorm (Some l1, i1), Gnorm (Some l2, i2) -> Int.equal i1 i2 && Label.equal l1 l2
  | Gnormtbl (None, i1), Gnormtbl (None, i2) -> Int.equal i1 i2
  | Gnormtbl (Some l1, i1), Gnormtbl (Some l2, i2) ->
      Int.equal i1 i2 && Label.equal l1 l2
  | Ginternal s1, Ginternal s2 -> String.equal s1 s2
  | Grel i1, Grel i2 -> Int.equal i1 i2
  | Gnamed id1, Gnamed id2 -> Id.equal id1 id2
  | (Gind _| Gconstruct _ | Gconstant _ | Gproj _ | Gcase _ | Gpred _
    | Gfixtype _ | Gnorm _ | Gnormtbl _ | Ginternal _ | Grel _ | Gnamed _), _ ->
      false

let dummy_gname =
  Grel 0

open Hashset.Combine

let gname_hash gn = match gn with
| Gind (s, ind) ->
   combinesmall 1 (combine (String.hash s) (ind_hash ind))
| Gconstruct (s, c) ->
   combinesmall 2 (combine (String.hash s) (constructor_hash c))
| Gconstant (s, c) ->
   combinesmall 3 (combine (String.hash s) (Constant.hash c))
| Gcase (l, i) -> combinesmall 4 (combine (Option.hash Label.hash l) (Int.hash i))
| Gpred (l, i) -> combinesmall 5 (combine (Option.hash Label.hash l) (Int.hash i))
| Gfixtype (l, i) -> combinesmall 6 (combine (Option.hash Label.hash l) (Int.hash i))
| Gnorm (l, i) -> combinesmall 7 (combine (Option.hash Label.hash l) (Int.hash i))
| Gnormtbl (l, i) -> combinesmall 8 (combine (Option.hash Label.hash l) (Int.hash i))
| Ginternal s -> combinesmall 9 (String.hash s)
| Grel i -> combinesmall 10 (Int.hash i)
| Gnamed id -> combinesmall 11 (Id.hash id)
| Gproj (s, p, i) -> combinesmall 12 (combine (String.hash s) (combine (ind_hash p) i))

let case_ctr = ref (-1)

let fresh_gcase l =
  incr case_ctr;
  Gcase (l,!case_ctr)

let pred_ctr = ref (-1)

let fresh_gpred l = 
  incr pred_ctr;
  Gpred (l,!pred_ctr)

let fixtype_ctr = ref (-1)

let fresh_gfixtype l =
  incr fixtype_ctr;
  Gfixtype (l,!fixtype_ctr)

let norm_ctr = ref (-1)

let fresh_gnorm l =
  incr norm_ctr;
  Gnorm (l,!norm_ctr)

let normtbl_ctr = ref (-1)

let fresh_gnormtbl l =
  incr normtbl_ctr;
  Gnormtbl (l,!normtbl_ctr)

(** Symbols (pre-computed values) **)

type symbol =
  | SymbValue of Nativevalues.t
  | SymbSort of Sorts.t
  | SymbName of Name.t
  | SymbConst of Constant.t
  | SymbMatch of annot_sw
  | SymbInd of inductive
  | SymbMeta of metavariable
  | SymbEvar of Evar.t
  | SymbLevel of Univ.Level.t
  | SymbProj of (inductive * int)

let dummy_symb = SymbValue (dummy_value ())

let eq_symbol sy1 sy2 =
  match sy1, sy2 with
  | SymbValue v1, SymbValue v2 -> Pervasives.(=) v1 v2 (** FIXME: how is this even valid? *)
  | SymbSort s1, SymbSort s2 -> Sorts.equal s1 s2
  | SymbName n1, SymbName n2 -> Name.equal n1 n2
  | SymbConst kn1, SymbConst kn2 -> Constant.equal kn1 kn2
  | SymbMatch sw1, SymbMatch sw2 -> eq_annot_sw sw1 sw2
  | SymbInd ind1, SymbInd ind2 -> eq_ind ind1 ind2
  | SymbMeta m1, SymbMeta m2 -> Int.equal m1 m2
  | SymbEvar evk1, SymbEvar evk2 -> Evar.equal evk1 evk2
  | SymbLevel l1, SymbLevel l2 -> Univ.Level.equal l1 l2
  | SymbProj (i1, k1), SymbProj (i2, k2) -> eq_ind i1 i2 && Int.equal k1 k2
  | _, _ -> false

let hash_symbol symb =
  match symb with
  | SymbValue v -> combinesmall 1 (Hashtbl.hash v) (** FIXME *)
  | SymbSort s -> combinesmall 2 (Sorts.hash s)
  | SymbName name -> combinesmall 3 (Name.hash name)
  | SymbConst c -> combinesmall 4 (Constant.hash c)
  | SymbMatch sw -> combinesmall 5 (hash_annot_sw sw)
  | SymbInd ind -> combinesmall 6 (ind_hash ind)
  | SymbMeta m -> combinesmall 7 m
  | SymbEvar evk -> combinesmall 8 (Evar.hash evk)
  | SymbLevel l -> combinesmall 9 (Univ.Level.hash l)
  | SymbProj (i, k) -> combinesmall 10 (combine (ind_hash i) k)

module HashedTypeSymbol = struct
  type t = symbol
  let equal = eq_symbol
  let hash = hash_symbol
end

module HashtblSymbol = Hashtbl.Make(HashedTypeSymbol)

let symb_tbl = HashtblSymbol.create 211

let clear_symbols () = HashtblSymbol.clear symb_tbl

type symbols = symbol array

let empty_symbols = [||]

let get_value tbl i =
  match tbl.(i) with
    | SymbValue v -> v
    | _ -> anomaly (Pp.str "get_value failed.")

let get_sort tbl i =
  match tbl.(i) with
    | SymbSort s -> s
    | _ -> anomaly (Pp.str "get_sort failed.")

let get_name tbl i =
  match tbl.(i) with
    | SymbName id -> id
    | _ -> anomaly (Pp.str "get_name failed.")

let get_const tbl i =
  match tbl.(i) with
    | SymbConst kn -> kn
    | _ -> anomaly (Pp.str "get_const failed.")

let get_match tbl i =
  match tbl.(i) with
    | SymbMatch case_info -> case_info
    | _ -> anomaly (Pp.str "get_match failed.")

let get_ind tbl i =
  match tbl.(i) with
    | SymbInd ind -> ind
    | _ -> anomaly (Pp.str "get_ind failed.")

let get_meta tbl i =
  match tbl.(i) with
    | SymbMeta m -> m
    | _ -> anomaly (Pp.str "get_meta failed.")

let get_evar tbl i =
  match tbl.(i) with
    | SymbEvar ev -> ev
    | _ -> anomaly (Pp.str "get_evar failed.")

let get_level tbl i =
  match tbl.(i) with
    | SymbLevel u -> u
    | _ -> anomaly (Pp.str "get_level failed.")

let get_proj tbl i =
  match tbl.(i) with
    | SymbProj p -> p
    | _ -> anomaly (Pp.str "get_proj failed.")

let push_symbol x =
  try HashtblSymbol.find symb_tbl x
  with Not_found ->
    let i = HashtblSymbol.length symb_tbl in
    HashtblSymbol.add symb_tbl x i; i

let symbols_tbl_name = Ginternal "symbols_tbl"

let get_symbols () =
  let tbl = Array.make (HashtblSymbol.length symb_tbl) dummy_symb in
  HashtblSymbol.iter (fun x i -> tbl.(i) <- x) symb_tbl; tbl

(** Lambda to Mllambda **)

type primitive =
  | Mk_prod
  | Mk_sort
  | Mk_ind
  | Mk_const
  | Mk_sw
  | Mk_fix of rec_pos * int 
  | Mk_cofix of int
  | Mk_rel of int
  | Mk_var of Id.t
  | Mk_proj
  | Is_int
  | Cast_accu
  | Upd_cofix
  | Force_cofix
  | Mk_uint
  | Mk_int
  | Mk_bool
  | Val_to_int
  | Mk_I31_accu
  | Decomp_uint
  | Mk_meta
  | Mk_evar
  | MLand
  | MLle
  | MLlt
  | MLinteq
  | MLlsl
  | MLlsr
  | MLland
  | MLlor
  | MLlxor
  | MLadd
  | MLsub
  | MLmul
  | MLmagic
  | MLarrayget
  | Mk_empty_instance
  | Coq_primitive of CPrimitives.t * (prefix * Constant.t) option

let eq_primitive p1 p2 =
  match p1, p2 with
  | Mk_prod, Mk_prod -> true
  | Mk_sort, Mk_sort -> true
  | Mk_ind, Mk_ind -> true
  | Mk_const, Mk_const -> true
  | Mk_sw, Mk_sw -> true
  | Mk_fix (rp1, i1), Mk_fix (rp2, i2) -> Int.equal i1 i2 && eq_rec_pos rp1 rp2
  | Mk_cofix i1, Mk_cofix i2 -> Int.equal i1 i2
  | Mk_rel i1, Mk_rel i2 -> Int.equal i1 i2
  | Mk_var id1, Mk_var id2 -> Id.equal id1 id2
  | Cast_accu, Cast_accu -> true
  | Upd_cofix, Upd_cofix -> true
  | Force_cofix, Force_cofix -> true
  | Mk_meta, Mk_meta -> true
  | Mk_evar, Mk_evar -> true
  | Mk_proj, Mk_proj -> true
  | MLarrayget, MLarrayget -> true

  | _ -> false

let primitive_hash = function
  | Mk_prod -> 1
  | Mk_sort -> 2
  | Mk_ind -> 3
  | Mk_const -> 4
  | Mk_sw -> 5
  | Mk_fix (r, i) ->
     let h = Array.fold_left (fun h i -> combine h (Int.hash i)) 0 r in
     combinesmall 6 (combine h (Int.hash i))
  | Mk_cofix i ->
     combinesmall 7 (Int.hash i)
  | Mk_rel i ->
     combinesmall 8 (Int.hash i)
  | Mk_var id ->
     combinesmall 9 (Id.hash id)
  | Is_int -> 11
  | Cast_accu -> 12
  | Upd_cofix -> 13
  | Force_cofix -> 14
  | Mk_uint -> 15
  | Mk_int -> 16
  | Mk_bool -> 17
  | Val_to_int -> 18
  | Mk_I31_accu -> 19
  | Decomp_uint -> 20
  | Mk_meta -> 21
  | Mk_evar -> 22
  | MLand -> 23
  | MLle -> 24
  | MLlt -> 25
  | MLinteq -> 26
  | MLlsl -> 27
  | MLlsr -> 28
  | MLland -> 29
  | MLlor -> 30
  | MLlxor -> 31
  | MLadd -> 32
  | MLsub -> 33
  | MLmul -> 34
  | MLmagic -> 35
  | Coq_primitive (prim, None) -> combinesmall 36 (CPrimitives.hash prim)
  | Coq_primitive (prim, Some (prefix,kn)) ->
     combinesmall 37 (combine3 (String.hash prefix) (Constant.hash kn) (CPrimitives.hash prim))
  | Mk_proj -> 38
  | MLarrayget -> 39
  | Mk_empty_instance -> 40

type mllambda =
  | MLlocal        of lname 
  | MLglobal       of gname 
  | MLprimitive    of primitive
  | MLlam          of lname array * mllambda 
  | MLletrec       of (lname * lname array * mllambda) array * mllambda
  | MLlet          of lname * mllambda * mllambda
  | MLapp          of mllambda * mllambda array
  | MLif           of mllambda * mllambda * mllambda
  | MLmatch        of annot_sw * mllambda * mllambda * mllam_branches
                              (* argument, prefix, accu branch, branches *)
  | MLconstruct    of string * constructor * mllambda array
                   (* prefix, constructor name, arguments *)
  | MLint          of int
  | MLuint         of Uint31.t
  | MLsetref       of string * mllambda
  | MLsequence     of mllambda * mllambda
  | MLarray        of mllambda array
  | MLisaccu       of string * inductive * mllambda

and mllam_branches = ((constructor * lname option array) list * mllambda) array

let push_lnames n env lns =
  snd (Array.fold_left (fun (i,r) x -> (i+1, LNmap.add x i r)) (n,env) lns)

let opush_lnames n env lns =
  let oadd x i r = match x with Some ln -> LNmap.add ln i r | None -> r in
  snd (Array.fold_left (fun (i,r) x -> (i+1, oadd x i r)) (n,env) lns)

(* Alpha-equivalence on mllambda *)
(* eq_mllambda gn1 gn2 n env1 env2 t1 t2 tests if t1 = t2 modulo gn1 = gn2 *)
let rec eq_mllambda gn1 gn2 n env1 env2 t1 t2 =
  match t1, t2 with
  | MLlocal ln1, MLlocal ln2 ->
     (try
      Int.equal (LNmap.find ln1 env1) (LNmap.find ln2 env2)
     with Not_found ->
      eq_lname ln1 ln2)
  | MLglobal gn1', MLglobal gn2' ->
      eq_gname gn1' gn2' || (eq_gname gn1 gn1' && eq_gname gn2 gn2')
      || (eq_gname gn1 gn2' && eq_gname gn2 gn1')
  | MLprimitive prim1, MLprimitive prim2 -> eq_primitive prim1 prim2
  | MLlam (lns1, ml1), MLlam (lns2, ml2) ->
      Int.equal (Array.length lns1) (Array.length lns2) &&
      let env1 = push_lnames n env1 lns1 in
      let env2 = push_lnames n env2 lns2 in
      eq_mllambda gn1 gn2 (n+Array.length lns1) env1 env2 ml1 ml2
  | MLletrec (defs1, body1), MLletrec (defs2, body2) ->
      Int.equal (Array.length defs1) (Array.length defs2) &&
      let lns1 = Array.map (fun (x,_,_) -> x) defs1 in
      let lns2 = Array.map (fun (x,_,_) -> x) defs2 in
      let env1 = push_lnames n env1 lns1 in
      let env2 = push_lnames n env2 lns2 in
      let n = n + Array.length defs1 in
      eq_letrec gn1 gn2 n env1 env2 defs1 defs2 &&
      eq_mllambda gn1 gn2 n env1 env2 body1 body2
  | MLlet (ln1, def1, body1), MLlet (ln2, def2, body2) ->
      eq_mllambda gn1 gn2 n env1 env2 def1 def2 &&
      let env1 = LNmap.add ln1 n env1 in
      let env2 = LNmap.add ln2 n env2 in
      eq_mllambda gn1 gn2 (n+1) env1 env2 body1 body2
  | MLapp (ml1, args1), MLapp (ml2, args2) ->
      eq_mllambda gn1 gn2 n env1 env2 ml1 ml2 &&
      Array.equal (eq_mllambda gn1 gn2 n env1 env2) args1 args2
  | MLif (cond1,br1,br'1), MLif (cond2,br2,br'2) ->
      eq_mllambda gn1 gn2 n env1 env2 cond1 cond2 &&
      eq_mllambda gn1 gn2 n env1 env2 br1 br2 &&
      eq_mllambda gn1 gn2 n env1 env2 br'1 br'2
  | MLmatch (annot1, c1, accu1, br1), MLmatch (annot2, c2, accu2, br2) ->
      eq_annot_sw annot1 annot2 &&
      eq_mllambda gn1 gn2 n env1 env2 c1 c2 &&
      eq_mllambda gn1 gn2 n env1 env2 accu1 accu2 &&
      eq_mllam_branches gn1 gn2 n env1 env2 br1 br2
  | MLconstruct (pf1, cs1, args1), MLconstruct (pf2, cs2, args2) ->
      String.equal pf1 pf2 &&
      eq_constructor cs1 cs2 &&
      Array.equal (eq_mllambda gn1 gn2 n env1 env2) args1 args2
  | MLint i1, MLint i2 ->
      Int.equal i1 i2
  | MLuint i1, MLuint i2 ->
      Uint31.equal i1 i2
  | MLsetref (id1, ml1), MLsetref (id2, ml2) ->
      String.equal id1 id2 &&
      eq_mllambda gn1 gn2 n env1 env2 ml1 ml2
  | MLsequence (ml1, ml'1), MLsequence (ml2, ml'2) ->
      eq_mllambda gn1 gn2 n env1 env2 ml1 ml2 &&
      eq_mllambda gn1 gn2 n env1 env2 ml'1 ml'2
  | MLarray arr1, MLarray arr2 ->
      Array.equal (eq_mllambda gn1 gn2 n env1 env2) arr1 arr2

  | MLisaccu (s1, ind1, ml1), MLisaccu (s2, ind2, ml2) ->
    String.equal s1 s2 && eq_ind ind1 ind2 &&
    eq_mllambda gn1 gn2 n env1 env2 ml1 ml2
  | (MLlocal _ | MLglobal _ | MLprimitive _ | MLlam _ | MLletrec _ | MLlet _ |
    MLapp _ | MLif _ | MLmatch _ | MLconstruct _ | MLint _ | MLuint _ |
    MLsetref _ | MLsequence _ | MLarray _ | MLisaccu _), _ -> false

and eq_letrec gn1 gn2 n env1 env2 defs1 defs2 =
  let eq_def (_,args1,ml1) (_,args2,ml2) =
    Int.equal (Array.length args1) (Array.length args2) &&
    let env1 = push_lnames n env1 args1 in
    let env2 = push_lnames n env2 args2 in
    eq_mllambda gn1 gn2 (n + Array.length args1) env1 env2 ml1 ml2
  in
  Array.equal eq_def defs1 defs2

(* we require here that patterns have the same order, which may be too strong *)
and eq_mllam_branches gn1 gn2 n env1 env2 br1 br2 =
  let eq_cargs (cs1, args1) (cs2, args2) body1 body2 =
    Int.equal (Array.length args1) (Array.length args2) &&
    eq_constructor cs1 cs2 &&
    let env1 = opush_lnames n env1 args1 in
    let env2 = opush_lnames n env2 args2 in
    eq_mllambda gn1 gn2 (n + Array.length args1) env1 env2 body1 body2
  in
  let eq_branch (ptl1,body1) (ptl2,body2) =
   List.equal (fun pt1 pt2 -> eq_cargs pt1 pt2 body1 body2) ptl1 ptl2
  in
  Array.equal eq_branch br1 br2

(* hash_mllambda gn n env t computes the hash for t ignoring occurrences of gn *)
let rec hash_mllambda gn n env t =
  match t with
  | MLlocal ln -> combinesmall 1 (LNmap.find ln env)
  | MLglobal gn' -> combinesmall 2 (if eq_gname gn gn' then 0 else gname_hash gn')
  | MLprimitive prim -> combinesmall 3 (primitive_hash prim)
  | MLlam (lns, ml) ->
      let env = push_lnames n env lns in
      combinesmall 4 (combine (Array.length lns) (hash_mllambda gn (n+1) env ml))
  | MLletrec (defs, body) ->
      let lns = Array.map (fun (x,_,_) -> x) defs in
      let env = push_lnames n env lns in
      let n = n + Array.length defs in
      let h = combine (hash_mllambda gn n env body) (Array.length defs) in
      combinesmall 5 (hash_mllambda_letrec gn n env h defs)
  | MLlet (ln, def, body) ->
      let hdef = hash_mllambda gn n env def in
      let env = LNmap.add ln n env in
      combinesmall 6 (combine hdef (hash_mllambda gn (n+1) env body))
  | MLapp (ml, args) ->
      let h = hash_mllambda gn n env ml in
      combinesmall 7 (hash_mllambda_array gn n env h args)
  | MLif (cond,br,br') ->
      let hcond = hash_mllambda gn n env cond in
      let hbr = hash_mllambda gn n env br in
      let hbr' = hash_mllambda gn n env br' in
      combinesmall 8 (combine3 hcond hbr hbr')
  | MLmatch (annot, c, accu, br) ->
      let hannot = hash_annot_sw annot in
      let hc = hash_mllambda gn n env c in
      let haccu = hash_mllambda gn n env accu in
      combinesmall 9 (hash_mllam_branches gn n env (combine3 hannot hc haccu) br)
  | MLconstruct (pf, cs, args) ->
      let hpf = String.hash pf in
      let hcs = constructor_hash cs in
      combinesmall 10 (hash_mllambda_array gn n env (combine hpf hcs) args)
  | MLint i ->
      combinesmall 11 i
  | MLuint i ->
      combinesmall 12 (Uint31.to_int i)
  | MLsetref (id, ml) ->
      let hid = String.hash id in
      let hml = hash_mllambda gn n env ml in
      combinesmall 13 (combine hid hml)
  | MLsequence (ml, ml') ->
      let hml = hash_mllambda gn n env ml in
      let hml' = hash_mllambda gn n env ml' in
      combinesmall 14 (combine hml hml')
  | MLarray arr ->
      combinesmall 15 (hash_mllambda_array gn n env 1 arr)
  | MLisaccu (s, ind, c) ->
      combinesmall 16 (combine (String.hash s) (combine (ind_hash ind) (hash_mllambda gn n env c)))

and hash_mllambda_letrec gn n env init defs =
  let hash_def (_,args,ml) =
    let env = push_lnames n env args in
    let nargs = Array.length args in
    combine nargs (hash_mllambda gn (n + nargs) env ml)
  in
  Array.fold_left (fun acc t -> combine (hash_def t) acc) init defs

and hash_mllambda_array gn n env init arr =
  Array.fold_left (fun acc t -> combine (hash_mllambda gn n env t) acc) init arr

and hash_mllam_branches gn n env init br =
  let hash_cargs (cs, args) body =
    let nargs = Array.length args in
    let hcs = constructor_hash cs in
    let env = opush_lnames n env args in
    let hbody = hash_mllambda gn (n + nargs) env body in
    combine3 nargs hcs hbody
  in
  let hash_branch acc (ptl,body) =
    List.fold_left (fun acc t -> combine (hash_cargs t body) acc) acc ptl
  in
  Array.fold_left hash_branch init br

let fv_lam l =
  let rec aux l bind fv =
    match l with
    | MLlocal l ->
	if LNset.mem l bind then fv else LNset.add l fv
    | MLglobal _ | MLprimitive _  | MLint _ | MLuint _ -> fv
    | MLlam (ln,body) ->
	let bind = Array.fold_right LNset.add ln bind in
	aux body bind fv
    | MLletrec(bodies,def) ->
	let bind = 
	  Array.fold_right (fun (id,_,_) b -> LNset.add id b) bodies bind in
	let fv_body (_,ln,body) fv =
	  let bind = Array.fold_right LNset.add ln bind in
	  aux body bind fv in
	Array.fold_right fv_body bodies (aux def bind fv)
    | MLlet(l,def,body) ->
	aux body (LNset.add l bind) (aux def bind fv)
    | MLapp(f,args) ->
	let fv_arg arg fv = aux arg bind fv in
	Array.fold_right fv_arg args (aux f bind fv)
    | MLif(t,b1,b2) ->
	aux t bind (aux b1 bind (aux b2 bind fv))
    | MLmatch(_,a,p,bs) ->
      let fv = aux a bind (aux p bind fv) in
      let fv_bs (cargs, body) fv =
	let bind = 
	  List.fold_right (fun (_,args) bind ->
	    Array.fold_right 
	      (fun o bind -> match o with 
	      | Some l -> LNset.add l bind 
	      | _ -> bind) args bind) 
	    cargs bind in
	aux body bind fv in
      Array.fold_right fv_bs bs fv
          (* argument, accu branch, branches *)
    | MLconstruct (_,_,p) ->
	Array.fold_right (fun a fv -> aux a bind fv) p fv
    | MLsetref(_,l) -> aux l bind fv
    | MLsequence(l1,l2) -> aux l1 bind (aux l2 bind fv)
    | MLarray arr -> Array.fold_right (fun a fv -> aux a bind fv) arr fv
    | MLisaccu (_, _, body) -> aux body bind fv
  in
  aux l LNset.empty LNset.empty


let mkMLlam params body =
  if Array.is_empty params then body 
  else
    match body with
    | MLlam (params', body) -> MLlam(Array.append params params', body)
    | _ -> MLlam(params,body)

let mkMLapp f args =
  if Array.is_empty args then f
  else
    match f with
    | MLapp(f,args') -> MLapp(f,Array.append args' args)
    | _ -> MLapp(f,args)

let mkForceCofix prefix ind arg =
  let name = fresh_lname Anonymous in
  MLlet (name, arg,
    MLif (
      MLisaccu (prefix, ind, MLlocal name),
      MLapp (MLprimitive Force_cofix, [|MLlocal name|]),
      MLlocal name))

let empty_params = [||]

let decompose_MLlam c =
  match c with
  | MLlam(ids,c) -> ids,c
  | _ -> empty_params,c

(*s Global declaration *)
type global =
(*  | Gtblname of gname * Id.t array *)
  | Gtblnorm of gname * lname array * mllambda array 
  | Gtblfixtype of gname * lname array * mllambda array
  | Glet of gname * mllambda
  | Gletcase of 
      gname * lname array * annot_sw * mllambda * mllambda * mllam_branches
  | Gopen of string
  | Gtype of inductive * int array
    (* ind name, arities of constructors *)
  | Gcomment of string

(* Alpha-equivalence on globals *)
let eq_global g1 g2 =
  match g1, g2 with
  | Gtblnorm (gn1,lns1,mls1), Gtblnorm (gn2,lns2,mls2)
  | Gtblfixtype (gn1,lns1,mls1), Gtblfixtype (gn2,lns2,mls2) ->
      Int.equal (Array.length lns1) (Array.length lns2) &&
      Int.equal (Array.length mls1) (Array.length mls2) &&
      let env1 = push_lnames 0 LNmap.empty lns1 in
      let env2 = push_lnames 0 LNmap.empty lns2 in
      Array.for_all2 (eq_mllambda gn1 gn2 (Array.length lns1) env1 env2) mls1 mls2
  | Glet (gn1, def1), Glet (gn2, def2) ->
      eq_mllambda gn1 gn2 0 LNmap.empty LNmap.empty def1 def2
  | Gletcase (gn1,lns1,annot1,c1,accu1,br1),
      Gletcase (gn2,lns2,annot2,c2,accu2,br2) ->
      Int.equal (Array.length lns1) (Array.length lns2) &&
      let env1 = push_lnames 0 LNmap.empty lns1 in
      let env2 = push_lnames 0 LNmap.empty lns2 in
      let t1 = MLmatch (annot1,c1,accu1,br1) in
      let t2 = MLmatch (annot2,c2,accu2,br2) in
      eq_mllambda gn1 gn2 (Array.length lns1) env1 env2 t1 t2
  | Gopen s1, Gopen s2 -> String.equal s1 s2
  | Gtype (ind1, arr1), Gtype (ind2, arr2) ->
      eq_ind ind1 ind2 && Array.equal Int.equal arr1 arr2
  | Gcomment s1, Gcomment s2 -> String.equal s1 s2
  | _, _ -> false

let hash_global g =
  match g with
  | Gtblnorm (gn,lns,mls) ->
      let nlns = Array.length lns in
      let nmls = Array.length mls in
      let env = push_lnames 0 LNmap.empty lns in
      let hmls = hash_mllambda_array gn nlns env (combine nlns nmls) mls in
      combinesmall 1 hmls
  | Gtblfixtype (gn,lns,mls) ->
      let nlns = Array.length lns in
      let nmls = Array.length mls in
      let env = push_lnames 0 LNmap.empty lns in
      let hmls = hash_mllambda_array gn nlns env (combine nlns nmls) mls in
      combinesmall 2 hmls
  | Glet (gn, def) ->
      combinesmall 3 (hash_mllambda gn 0 LNmap.empty def)
  | Gletcase (gn,lns,annot,c,accu,br) ->
      let nlns = Array.length lns in
      let env = push_lnames 0 LNmap.empty lns in
      let t = MLmatch (annot,c,accu,br) in
      combinesmall 4 (combine nlns (hash_mllambda gn nlns env t))
  | Gopen s -> combinesmall 5 (String.hash s)
  | Gtype (ind, arr) ->
      combinesmall 6 (combine (ind_hash ind) (Array.fold_left combine 0 arr))
  | Gcomment s -> combinesmall 7 (String.hash s)
  
let global_stack = ref ([] : global list)

module HashedTypeGlobal = struct
  type t = global
  let equal = eq_global
  let hash = hash_global
end

module HashtblGlobal = Hashtbl.Make(HashedTypeGlobal)

let global_tbl = HashtblGlobal.create 19991

let clear_global_tbl () = HashtblGlobal.clear global_tbl

let push_global gn t =
  try HashtblGlobal.find global_tbl t
  with Not_found ->
    (global_stack := t :: !global_stack;
    HashtblGlobal.add global_tbl t gn; gn)

let push_global_let gn body =
  push_global gn (Glet (gn,body))

let push_global_fixtype gn params body =
  push_global gn (Gtblfixtype (gn,params,body))

let push_global_norm gn params body =
  push_global gn (Gtblnorm (gn, params, body))

let push_global_case gn params annot a accu bs =
  push_global gn (Gletcase (gn, params, annot, a, accu, bs))

(* Compares [t1] and [t2] up to alpha-equivalence. [t1] and [t2] may contain
   free variables. *)
let eq_mllambda t1 t2 =
  eq_mllambda dummy_gname dummy_gname 0 LNmap.empty LNmap.empty t1 t2

(*s Compilation environment *)

type env =
    { env_rel : mllambda list; (* (MLlocal lname) list *)
      env_bound : int; (* length of env_rel *)
      (* free variables *)
      env_urel : (int * mllambda) list ref; (* list of unbound rel *)
      env_named : (Id.t * mllambda) list ref;
      env_univ : lname option}

let empty_env univ () =
  { env_rel = [];
    env_bound = 0;
    env_urel = ref [];
    env_named = ref [];
    env_univ = univ
  }

let push_rel env id = 
  let local = fresh_lname id in
  local, { env with 
	   env_rel = MLlocal local :: env.env_rel;
	   env_bound = env.env_bound + 1
	 }

let push_rels env ids =
  let lnames, env_rel = 
    Array.fold_left (fun (names,env_rel) id ->
      let local = fresh_lname id in
      (local::names, MLlocal local::env_rel)) ([],env.env_rel) ids in
  Array.of_list (List.rev lnames), { env with 
			  env_rel = env_rel;
			  env_bound = env.env_bound + Array.length ids
			}

let get_rel env id i =
  if i <= env.env_bound then
    List.nth env.env_rel (i-1)
  else 
    let i = i - env.env_bound in
    try Int.List.assoc i !(env.env_urel)
    with Not_found ->
      let local = MLlocal (fresh_lname id) in
      env.env_urel := (i,local) :: !(env.env_urel);
      local

let get_var env id =
  try Id.List.assoc id !(env.env_named)
  with Not_found ->
    let local = MLlocal (fresh_lname (Name id)) in
    env.env_named := (id, local)::!(env.env_named);
    local

let fresh_univ () =
  fresh_lname (Name (Id.of_string "univ"))

(*s Traduction of lambda to mllambda *)

let get_prod_name codom = 
  match codom with
  | MLlam(ids,_) -> ids.(0).lname
  | _ -> assert false

let get_lname (_,l) = 
  match l with
  | MLlocal id -> id
  | _ -> invalid_arg "Nativecode.get_lname"

(* Collects free variables from env in an array of local names *)
let fv_params env = 
  let fvn, fvr = !(env.env_named), !(env.env_urel) in 
  let size = List.length fvn + List.length fvr in
  let start,params = match env.env_univ with
    | None -> 0, Array.make size dummy_lname
    | Some u -> 1, let t = Array.make (size + 1) dummy_lname in t.(0) <- u; t
  in
  if Array.is_empty params then empty_params
  else begin
    let fvn = ref fvn in
    let i = ref start in
    while not (List.is_empty !fvn) do
      params.(!i) <- get_lname (List.hd !fvn);
      fvn := List.tl !fvn;
      incr i
    done;
    let fvr = ref fvr in
    while not (List.is_empty !fvr) do
      params.(!i) <- get_lname (List.hd !fvr);
      fvr := List.tl !fvr;
      incr i
    done;
    params
  end

let generalize_fv env body = 
  mkMLlam (fv_params env) body

let empty_args = [||]

let fv_args env fvn fvr =
  let size = List.length fvn + List.length fvr in
  let start,args = match env.env_univ with
    | None -> 0, Array.make size (MLint 0)
    | Some u -> 1, let t = Array.make (size + 1) (MLint 0) in t.(0) <- MLlocal u; t
  in
  if Array.is_empty args then empty_args
  else 
    begin
      let fvn = ref fvn in
      let i = ref start in
      while not (List.is_empty !fvn) do
	args.(!i) <- get_var env (fst (List.hd !fvn));
	fvn := List.tl !fvn;
	incr i
      done;
      let fvr = ref fvr in
      while not (List.is_empty !fvr) do
	let (k,_ as kml) = List.hd !fvr in
	let n = get_lname kml in 
	args.(!i) <- get_rel env n.lname k;
	fvr := List.tl !fvr;
	incr i
      done;
      args
    end

let get_value_code i =
  MLapp (MLglobal (Ginternal "get_value"),
    [|MLglobal symbols_tbl_name; MLint i|])

let get_sort_code i =
  MLapp (MLglobal (Ginternal "get_sort"),
    [|MLglobal symbols_tbl_name; MLint i|])

let get_name_code i =
  MLapp (MLglobal (Ginternal "get_name"),
    [|MLglobal symbols_tbl_name; MLint i|])

let get_const_code i =
  MLapp (MLglobal (Ginternal "get_const"),
    [|MLglobal symbols_tbl_name; MLint i|])

let get_match_code i =
  MLapp (MLglobal (Ginternal "get_match"),
    [|MLglobal symbols_tbl_name; MLint i|])

let get_ind_code i =
  MLapp (MLglobal (Ginternal "get_ind"),
    [|MLglobal symbols_tbl_name; MLint i|])

let get_meta_code i =
  MLapp (MLglobal (Ginternal "get_meta"),
    [|MLglobal symbols_tbl_name; MLint i|])

let get_evar_code i =
  MLapp (MLglobal (Ginternal "get_evar"),
    [|MLglobal symbols_tbl_name; MLint i|])

let get_level_code i =
  MLapp (MLglobal (Ginternal "get_level"),
    [|MLglobal symbols_tbl_name; MLint i|])

let get_proj_code i =
  MLapp (MLglobal (Ginternal "get_proj"),
    [|MLglobal symbols_tbl_name; MLint i|])

type rlist =
  | Rnil 
  | Rcons of (constructor * lname option array) list ref * LNset.t * mllambda * rlist' 
and rlist' = rlist ref

let rm_params fv params = 
  Array.map (fun l -> if LNset.mem l fv then Some l else None) params 

let rec insert cargs body rl =
 match !rl with
 | Rnil ->
     let fv = fv_lam body in
     let (c,params) = cargs in
     let params = rm_params fv params in
     rl:= Rcons(ref [(c,params)], fv, body, ref Rnil)
 | Rcons(l,fv,body',rl) ->
     if eq_mllambda body body' then
       let (c,params) = cargs in
       let params = rm_params fv params in
       l := (c,params)::!l
     else insert cargs body rl

let rec to_list rl =
  match !rl with
  | Rnil -> []
  | Rcons(l,_,body,tl) -> (!l,body)::to_list tl

let merge_branches t =
  let newt = ref Rnil in
  Array.iter (fun (c,args,body) -> insert (c,args) body newt) t;
  Array.of_list (to_list newt)


type prim_aux = 
  | PAprim of string * Constant.t * CPrimitives.t * prim_aux array
  | PAml of mllambda

let add_check cond args =
  let aux cond a = 
    match a with
    | PAml(MLint _) -> cond
    | PAml ml ->
       (* FIXME: use explicit equality function *)
       if List.mem ml cond then cond else ml::cond 
    | _ -> cond
  in
  Array.fold_left aux cond args
  
let extract_prim ml_of l =
  let decl = ref [] in
  let cond = ref [] in
  let rec aux l = 
    match l with
    | Lprim(prefix,kn,p,args) ->
	let args = Array.map aux args in
	cond := add_check !cond args;
	PAprim(prefix,kn,p,args)
    | Lrel _ | Lvar _ | Luint _ | Lval _ | Lconst _ -> PAml (ml_of l)
    | _ -> 
	let x = fresh_lname Anonymous in
	decl := (x,ml_of l)::!decl;
	PAml (MLlocal x) in
  let res = aux l in
  (!decl, !cond, res)

let app_prim p args = MLapp(MLprimitive p, args)

let to_int v =
  match v with
  | MLapp(MLprimitive Mk_uint, t) ->
     begin match t.(0) with
     | MLuint i -> MLint (Uint31.to_int i)
     | _ -> MLapp(MLprimitive Val_to_int, [|v|])
     end
  | MLapp(MLprimitive Mk_int, t) -> t.(0)
  | _ -> MLapp(MLprimitive Val_to_int, [|v|]) 

let of_int v = 
  match v with
  | MLapp(MLprimitive Val_to_int, t) -> t.(0)
  | _ -> MLapp(MLprimitive Mk_int,[|v|]) 

let compile_prim decl cond paux =
(*
  let args_to_int args = 
    for i = 0 to Array.length args - 1 do
      args.(i) <- to_int args.(i)
    done;
    args in
 *)
  let rec opt_prim_aux paux =
    match paux with
    | PAprim(prefix, kn, op, args) ->
	let args = Array.map opt_prim_aux args in
	app_prim (Coq_primitive(op,None)) args
(*
    TODO: check if this inlining was useful
	begin match op with
        | Int31lt -> 
           if Sys.word_size = 64 then
             app_prim Mk_bool [|(app_prim MLlt (args_to_int args))|]
           else app_prim (Coq_primitive (CPrimitives.Int31lt,None)) args
        | Int31le ->
           if Sys.word_size = 64 then
             app_prim Mk_bool [|(app_prim MLle (args_to_int args))|]
           else app_prim (Coq_primitive (CPrimitives.Int31le, None)) args
	| Int31lsl  -> of_int (mk_lsl (args_to_int args))
	| Int31lsr  -> of_int (mk_lsr (args_to_int args))
	| Int31land -> of_int (mk_land (args_to_int args))
	| Int31lor  -> of_int (mk_lor (args_to_int args))
	| Int31lxor -> of_int (mk_lxor (args_to_int args))
	| Int31add  -> of_int (mk_add (args_to_int args))
	| Int31sub  -> of_int (mk_sub (args_to_int args))
	| Int31mul  -> of_int (mk_mul (args_to_int args))
	| _ -> app_prim (Coq_primitive(op,None)) args
	end *)
    | PAml ml -> ml 
  and naive_prim_aux paux = 
    match paux with
    | PAprim(prefix, kn, op, args) ->
        app_prim (Coq_primitive(op, Some (prefix, kn))) (Array.map naive_prim_aux args)
    | PAml ml -> ml in

  let compile_cond cond paux = 
    match cond with
    | [] -> opt_prim_aux paux 
    | [c1] ->
        MLif(app_prim Is_int [|c1|], opt_prim_aux paux, naive_prim_aux paux) 
    | c1::cond ->
	let cond = 
	  List.fold_left 
	    (fun ml c -> app_prim MLland [| ml; to_int c|])
            (app_prim MLland [|to_int c1; MLint 0 |]) cond in
        let cond = app_prim MLmagic [|cond|] in
	MLif(cond, naive_prim_aux paux, opt_prim_aux paux) in
  let add_decl decl body =
    List.fold_left (fun body (x,d) -> MLlet(x,d,body)) body decl in
  add_decl decl (compile_cond cond paux)

let ml_of_instance instance u =
  let ml_of_level l =
    match Univ.Level.var_index l with
    | Some i ->
       let univ = MLapp(MLprimitive MLmagic, [|MLlocal (Option.get instance)|]) in
       mkMLapp (MLprimitive MLarrayget) [|univ; MLint i|]
    | None -> let i = push_symbol (SymbLevel l) in get_level_code i
  in
  let u = Univ.Instance.to_array u in
  if Array.is_empty u then [||]
  else let u = Array.map ml_of_level u in
       [|MLapp (MLprimitive MLmagic, [|MLarray u|])|]

 let rec ml_of_lam env l t =
  match t with
  | Lrel(id ,i) -> get_rel env id i
  | Lvar id -> get_var env id
  | Lmeta(mv,ty) ->
     let tyn = fresh_lname Anonymous in
     let i = push_symbol (SymbMeta mv) in
     MLapp(MLprimitive Mk_meta, [|get_meta_code i; MLlocal tyn|])
  | Levar(evk, args) ->
     let i = push_symbol (SymbEvar evk) in
     (** Arguments are *not* reversed in evar instances in native compilation *)
     let args = MLarray(Array.map (ml_of_lam env l) args) in
     MLapp(MLprimitive Mk_evar, [|get_evar_code i; args|])
  | Lprod(dom,codom) ->
      let dom = ml_of_lam env l dom in
      let codom = ml_of_lam env l codom in
      let n = get_prod_name codom in
      let i = push_symbol (SymbName n) in
      MLapp(MLprimitive Mk_prod, [|get_name_code i;dom;codom|])
  | Llam(ids,body) ->
    let lnames,env = push_rels env ids in
    MLlam(lnames, ml_of_lam env l body)
  | Llet(id,def,body) ->
      let def = ml_of_lam env l def in
      let lname, env = push_rel env id in
      let body = ml_of_lam env l body in
      MLlet(lname,def,body)
  | Lapp(f,args) ->
      MLapp(ml_of_lam env l f, Array.map (ml_of_lam env l) args)
  | Lconst (prefix, (c, u)) ->
     let args = ml_of_instance env.env_univ u in
     mkMLapp (MLglobal(Gconstant (prefix, c))) args
  | Lproj (prefix, ind, i) -> MLglobal(Gproj (prefix, ind, i))
  | Lprim _ ->
      let decl,cond,paux = extract_prim (ml_of_lam env l) t in
      compile_prim decl cond paux
  | Lcase (annot,p,a,bs) ->
      (* let predicate_uid fv_pred = compilation of p 
         let rec case_uid fv a_uid = 
           match a_uid with
           | Accu _ => mk_sw (predicate_uid fv_pred) (case_uid fv) a_uid
           | Ci argsi => compilation of branches 
         compile case = case_uid fv (compilation of a) *)
      (* Compilation of the predicate *)
         (* Remark: if we do not want to compile the predicate we 
            should a least compute the fv, then store the lambda representation
            of the predicate (not the mllambda) *)
      let env_p = empty_env env.env_univ () in
      let pn = fresh_gpred l in
      let mlp = ml_of_lam env_p l p in
      let mlp = generalize_fv env_p mlp in
      let (pfvn,pfvr) = !(env_p.env_named), !(env_p.env_urel) in
      let pn = push_global_let pn mlp in
      (* Compilation of the case *)
      let env_c = empty_env env.env_univ () in
      let a_uid = fresh_lname Anonymous in
      let la_uid = MLlocal a_uid in
      (* compilation of branches *)
      let ml_br (c,params, body) = 
	let lnames, env_c = push_rels env_c params in
	(c, lnames, ml_of_lam env_c l body)
      in
      let bs = Array.map ml_br bs in
      let cn = fresh_gcase l in
      (* Compilation of accu branch *)
      let pred = MLapp(MLglobal pn, fv_args env_c pfvn pfvr) in  
      let (fvn, fvr) = !(env_c.env_named), !(env_c.env_urel) in
      let cn_fv = mkMLapp (MLglobal cn) (fv_args env_c fvn fvr) in
         (* remark : the call to fv_args does not add free variables in env_c *)
      let i = push_symbol (SymbMatch annot) in
      let accu =
	MLapp(MLprimitive Mk_sw,
	      [| get_match_code i; MLapp (MLprimitive Cast_accu, [|la_uid|]);
		 pred;
		 cn_fv |]) in
(*      let body = MLlam([|a_uid|], MLmatch(annot, la_uid, accu, bs)) in
      let case = generalize_fv env_c body in *)
      let cn = push_global_case cn (Array.append (fv_params env_c) [|a_uid|])
        annot la_uid accu (merge_branches bs)
      in
      (* Final result *)
      let arg = ml_of_lam env l a in
      let force =
	if annot.asw_finite then arg
        else mkForceCofix annot.asw_prefix annot.asw_ind arg in
      mkMLapp (MLapp (MLglobal cn, fv_args env fvn fvr)) [|force|]
  | Lif(t,bt,bf) -> 
      MLif(ml_of_lam env l t, ml_of_lam env l bt, ml_of_lam env l bf)
  | Lfix ((rec_pos, inds, start), (ids, tt, tb)) ->
      (* let type_f fvt = [| type fix |] 
         let norm_f1 fv f1 .. fn params1 = body1
	 ..
         let norm_fn fv f1 .. fn paramsn = bodyn
         let norm fv f1 .. fn = 
	    [|norm_f1 fv f1 .. fn; ..; norm_fn fv f1 .. fn|]
         compile fix = 
	   let rec f1 params1 = 
             if is_accu rec_pos.(1) then mk_fix (type_f fvt) (norm fv) params1
	     else norm_f1 fv f1 .. fn params1
           and .. and fn paramsn = 
	     if is_accu rec_pos.(n) then mk_fix (type_f fvt) (norm fv) paramsn
             else norm_fn fv f1 .. fv paramsn in
	   start
      *)
      (* Compilation of type *)
      let env_t = empty_env env.env_univ () in
      let ml_t = Array.map (ml_of_lam env_t l) tt in
      let params_t = fv_params env_t in
      let args_t = fv_args env !(env_t.env_named) !(env_t.env_urel) in
      let gft = fresh_gfixtype l in
      let gft = push_global_fixtype gft params_t ml_t in
      let mk_type = MLapp(MLglobal gft, args_t) in
      (* Compilation of norm_i *)
      let ndef = Array.length ids in
      let lf,env_n = push_rels (empty_env env.env_univ ()) ids in
      let t_params = Array.make ndef [||] in
      let t_norm_f = Array.make ndef (Gnorm (l,-1)) in
      let mk_let envi (id,def) t = MLlet (id,def,t) in
      let mk_lam_or_let (params,lets,env) (id,def) =
        let ln,env' = push_rel env id in
        match def with
        | None -> (ln::params,lets,env')
        | Some lam -> (params, (ln,ml_of_lam env l lam)::lets,env')
      in
      let ml_of_fix i body =
        let varsi, bodyi = decompose_Llam_Llet body in
        let paramsi,letsi,envi = 
          Array.fold_left mk_lam_or_let ([],[],env_n) varsi
        in
        let paramsi,letsi =
          Array.of_list (List.rev paramsi), Array.of_list (List.rev letsi)
        in
        t_norm_f.(i) <- fresh_gnorm l;
        let bodyi = ml_of_lam envi l bodyi in
        t_params.(i) <- paramsi;
        let bodyi = Array.fold_right (mk_let envi) letsi bodyi in
        mkMLlam paramsi bodyi
      in
      let tnorm = Array.mapi ml_of_fix tb in
      let fvn,fvr = !(env_n.env_named), !(env_n.env_urel) in
      let fv_params = fv_params env_n in
      let fv_args' = Array.map (fun id -> MLlocal id) fv_params in
      let norm_params = Array.append fv_params lf in
      let t_norm_f = Array.mapi (fun i body ->
	push_global_let (t_norm_f.(i)) (mkMLlam norm_params body)) tnorm in
      let norm = fresh_gnormtbl l in
      let norm = push_global_norm norm fv_params 
         (Array.map (fun g -> mkMLapp (MLglobal g) fv_args') t_norm_f) in
      (* Compilation of fix *)
      let fv_args = fv_args env fvn fvr in      
      let lf, env = push_rels env ids in
      let lf_args = Array.map (fun id -> MLlocal id) lf in
      let mk_norm = MLapp(MLglobal norm, fv_args) in
      let mkrec i lname = 
	let paramsi = t_params.(i) in
	let reci = MLlocal (paramsi.(rec_pos.(i))) in
	let pargsi = Array.map (fun id -> MLlocal id) paramsi in
        let (prefix, ind) = inds.(i) in
	let body = 
          MLif(MLisaccu (prefix, ind, reci),
	       mkMLapp 
		 (MLapp(MLprimitive (Mk_fix(rec_pos,i)), 
			[|mk_type; mk_norm|]))
		 pargsi,
	       MLapp(MLglobal t_norm_f.(i), 
		     Array.concat [fv_args;lf_args;pargsi])) 
	in
	(lname, paramsi, body) in
      MLletrec(Array.mapi mkrec lf, lf_args.(start))
  | Lcofix (start, (ids, tt, tb)) -> 
      (* Compilation of type *)
      let env_t = empty_env env.env_univ () in
      let ml_t = Array.map (ml_of_lam env_t l) tt in
      let params_t = fv_params env_t in
      let args_t = fv_args env !(env_t.env_named) !(env_t.env_urel) in
      let gft = fresh_gfixtype l in
      let gft = push_global_fixtype gft params_t ml_t in
      let mk_type = MLapp(MLglobal gft, args_t) in
      (* Compilation of norm_i *) 
      let ndef = Array.length ids in
      let lf,env_n = push_rels (empty_env env.env_univ ()) ids in
      let t_params = Array.make ndef [||] in
      let t_norm_f = Array.make ndef (Gnorm (l,-1)) in
      let ml_of_fix i body =
        let idsi,bodyi = decompose_Llam body in
        let paramsi, envi = push_rels env_n idsi in
        t_norm_f.(i) <- fresh_gnorm l;
        let bodyi = ml_of_lam envi l bodyi in
        t_params.(i) <- paramsi;
        mkMLlam paramsi bodyi in
      let tnorm = Array.mapi ml_of_fix tb in
      let fvn,fvr = !(env_n.env_named), !(env_n.env_urel) in
      let fv_params = fv_params env_n in
      let fv_args' = Array.map (fun id -> MLlocal id) fv_params in
      let norm_params = Array.append fv_params lf in
      let t_norm_f = Array.mapi (fun i body ->
	push_global_let (t_norm_f.(i)) (mkMLlam norm_params body)) tnorm in
      let norm = fresh_gnormtbl l in
      let norm = push_global_norm norm fv_params
        (Array.map (fun g -> mkMLapp (MLglobal g) fv_args') t_norm_f) in
      (* Compilation of fix *)
      let fv_args = fv_args env fvn fvr in      
      let mk_norm = MLapp(MLglobal norm, fv_args) in
      let lnorm = fresh_lname Anonymous in
      let ltype = fresh_lname Anonymous in
      let lf, env = push_rels env ids in
      let lf_args = Array.map (fun id -> MLlocal id) lf in
      let upd i lname cont =
	let paramsi = t_params.(i) in
	let pargsi = Array.map (fun id -> MLlocal id) paramsi in
	let uniti = fresh_lname Anonymous in
	let body =
	  MLlam(Array.append paramsi [|uniti|],
		MLapp(MLglobal t_norm_f.(i),
		      Array.concat [fv_args;lf_args;pargsi])) in
	MLsequence(MLapp(MLprimitive Upd_cofix, [|lf_args.(i);body|]),
		   cont) in
      let upd = Array.fold_right_i upd lf lf_args.(start) in
      let mk_let i lname cont =
	MLlet(lname,
	      MLapp(MLprimitive(Mk_cofix i),[| MLlocal ltype; MLlocal lnorm|]),
	      cont) in
      let init = Array.fold_right_i mk_let lf upd in 
      MLlet(lnorm, mk_norm, MLlet(ltype, mk_type, init))
  (*    	    
      let mkrec i lname = 
	let paramsi = t_params.(i) in
	let pargsi = Array.map (fun id -> MLlocal id) paramsi in
	let uniti = fresh_lname Anonymous in
	let body = 
	  MLapp( MLprimitive(Mk_cofix i),
		 [|mk_type;mk_norm; 
		   MLlam([|uniti|],
			 MLapp(MLglobal t_norm_f.(i),
			       Array.concat [fv_args;lf_args;pargsi]))|]) in
	(lname, paramsi, body) in
      MLletrec(Array.mapi mkrec lf, lf_args.(start)) *)

  | Lmakeblock (prefix,(cn,u),_,args) ->
     let args = Array.map (ml_of_lam env l) args in
     MLconstruct(prefix,cn,args)
  | Lconstruct (prefix, (cn,u)) ->
     let uargs = ml_of_instance env.env_univ u in
      mkMLapp (MLglobal (Gconstruct (prefix, cn))) uargs
  | Luint v ->
     (match v with
     | UintVal i -> MLapp(MLprimitive Mk_uint, [|MLuint i|])
     | UintDigits (prefix,cn,ds) ->
	let c = MLglobal (Gconstruct (prefix, cn)) in
	let ds = Array.map (ml_of_lam env l) ds in
	let i31 = MLapp (MLprimitive Mk_I31_accu, [|c|]) in
	MLapp(i31, ds)
     | UintDecomp (prefix,cn,t) ->
	let c = MLglobal (Gconstruct (prefix, cn)) in
	let t = ml_of_lam env l t in
	MLapp (MLprimitive Decomp_uint, [|c;t|]))
  | Lval v ->
      let i = push_symbol (SymbValue v) in get_value_code i
  | Lsort s ->
    let i = push_symbol (SymbSort s) in
    let uarg = match env.env_univ with
      | None -> MLarray [||]
      | Some u -> MLlocal u
    in
    let uarg = MLapp(MLprimitive MLmagic, [|uarg|]) in
    MLapp(MLprimitive Mk_sort, [|get_sort_code i; uarg|])
  | Lind (prefix, (ind, u)) ->
     let uargs = ml_of_instance env.env_univ u in
     mkMLapp (MLglobal (Gind (prefix, ind))) uargs
  | Llazy -> MLglobal (Ginternal "lazy")
  | Lforce -> MLglobal (Ginternal "Lazy.force")

let mllambda_of_lambda univ auxdefs l t =
  let env = empty_env univ () in
  global_stack := auxdefs;
  let ml = ml_of_lam env l t in
  let fv_rel = !(env.env_urel) in
  let fv_named = !(env.env_named) in
  (* build the free variables *)
  let get_lname (_,t) = 
   match t with
   | MLlocal x -> x
   | _ -> assert false in
  let params = 
    List.append (List.map get_lname fv_rel) (List.map get_lname fv_named) in
  if List.is_empty params then
    (!global_stack, ([],[]), ml)
  (* final result : global list, fv, ml *)
  else
    (!global_stack, (fv_named, fv_rel), mkMLlam (Array.of_list params) ml)

(** Code optimization **)

(** Optimization of match and fix *)

let can_subst l = 
  match l with
  | MLlocal _ | MLint _ | MLuint _ | MLglobal _ -> true
  | _ -> false

let subst s l =
  if LNmap.is_empty s then l 
  else
    let rec aux l =
      match l with
      | MLlocal id -> (try LNmap.find id s with Not_found -> l)
      | MLglobal _ | MLprimitive _ | MLint _ | MLuint _ -> l
      | MLlam(params,body) -> MLlam(params, aux body)
      | MLletrec(defs,body) ->
	let arec (f,params,body) = (f,params,aux body) in
	MLletrec(Array.map arec defs, aux body)
      | MLlet(id,def,body) -> MLlet(id,aux def, aux body)
      | MLapp(f,args) -> MLapp(aux f, Array.map aux args)
      | MLif(t,b1,b2) -> MLif(aux t, aux b1, aux b2)
      | MLmatch(annot,a,accu,bs) ->
	  let auxb (cargs,body) = (cargs,aux body) in
	  MLmatch(annot,a,aux accu, Array.map auxb bs)
      | MLconstruct(prefix,c,args) -> MLconstruct(prefix,c,Array.map aux args)
      | MLsetref(s,l1) -> MLsetref(s,aux l1) 
      | MLsequence(l1,l2) -> MLsequence(aux l1, aux l2)
      | MLarray arr -> MLarray (Array.map aux arr)
      | MLisaccu (s, ind, l) -> MLisaccu (s, ind, aux l)
    in
    aux l

let add_subst id v s =
  match v with
  | MLlocal id' when Int.equal id.luid id'.luid -> s
  | _ -> LNmap.add id v s

let subst_norm params args s =
  let len = Array.length params in
  assert (Int.equal (Array.length args) len && Array.for_all can_subst args);
  let s = ref s in
  for i = 0 to len - 1 do
    s := add_subst params.(i) args.(i) !s
  done;
  !s

let subst_case params args s =
  let len = Array.length params in
  assert (len > 0 && 
	  Int.equal (Array.length args) len && 
	  let r = ref true and i = ref 0 in
	  (* we test all arguments excepted the last *)
	  while !i < len - 1  && !r do r := can_subst args.(!i); incr i done;
	  !r);
  let s = ref s in
  for i = 0 to len - 2 do
    s := add_subst params.(i) args.(i) !s
  done;
  !s, params.(len-1), args.(len-1)
    
let empty_gdef = Int.Map.empty, Int.Map.empty
let get_norm (gnorm, _) i = Int.Map.find i gnorm
let get_case (_, gcase) i = Int.Map.find i gcase

let all_lam n bs = 
  let f (_, l) = 
    match l with
    | MLlam(params, _) -> Int.equal (Array.length params) n
    | _ -> false in
  Array.for_all f bs

let commutative_cut annot a accu bs args =
  let mkb (c,b) =
     match b with
     | MLlam(params, body) -> 
         (c, Array.fold_left2 (fun body x v -> MLlet(x,v,body)) body params args)
     | _ -> assert false in
  MLmatch(annot, a, mkMLapp accu args, Array.map mkb bs)

let optimize gdef l =   
  let rec optimize s l =
    match l with
    | MLlocal id -> (try LNmap.find id s with Not_found -> l)
    | MLglobal _ | MLprimitive _ | MLint _ | MLuint _ -> l
    | MLlam(params,body) -> 
	MLlam(params, optimize s body)
    | MLletrec(decls,body) ->
	let opt_rec (f,params,body) = (f,params,optimize s body ) in 
	MLletrec(Array.map opt_rec decls, optimize s body)
    | MLlet(id,def,body) ->
	let def = optimize s def in
	if can_subst def then optimize (add_subst id def s) body 
	else MLlet(id,def,optimize s body)
    | MLapp(f, args) ->
	let args = Array.map (optimize s) args in
	begin match f with
	| MLglobal (Gnorm (_,i)) ->
	    (try
	      let params,body = get_norm gdef i in
	      let s = subst_norm params args s in
	      optimize s body	    
	    with Not_found -> MLapp(optimize s f, args))
	| MLglobal (Gcase (_,i)) ->
	    (try 
	      let params,body = get_case gdef i in
	      let s, id, arg = subst_case params args s in
	      if can_subst arg then optimize (add_subst id arg s) body
	      else MLlet(id, arg, optimize s body)
	    with Not_found ->  MLapp(optimize s f, args))
	| _ -> 
            let f = optimize s f in
            match f with
            | MLmatch (annot,a,accu,bs) ->
              if all_lam (Array.length args) bs then  
                commutative_cut annot a accu bs args 
              else MLapp(f, args)
            | _ -> MLapp(f, args)

	end
    | MLif(t,b1,b2) ->
       (* This optimization is critical: it applies to all fixpoints that start
       by matching on their recursive argument *)
	let t = optimize s t in
	let b1 = optimize s b1 in
	let b2 = optimize s b2 in
	begin match t, b2 with
        | MLisaccu (_, _, l1), MLmatch(annot, l2, _, bs)
	    when eq_mllambda l1 l2 -> MLmatch(annot, l1, b1, bs)
        | _, _ -> MLif(t, b1, b2)
	end
    | MLmatch(annot,a,accu,bs) ->
	let opt_b (cargs,body) = (cargs,optimize s body) in
	MLmatch(annot, optimize s a, subst s accu, Array.map opt_b bs)
    | MLconstruct(prefix,c,args) ->
        MLconstruct(prefix,c,Array.map (optimize s) args)
    | MLsetref(r,l) -> MLsetref(r, optimize s l) 
    | MLsequence(l1,l2) -> MLsequence(optimize s l1, optimize s l2)
    | MLarray arr -> MLarray (Array.map (optimize s) arr)
    | MLisaccu (pf, ind, l) -> MLisaccu (pf, ind, optimize s l)
  in
  optimize LNmap.empty l

let optimize_stk stk =
  let add_global gdef g =
    match g with
    | Glet (Gnorm (_,i), body) ->
	let (gnorm, gcase) = gdef in
	(Int.Map.add i (decompose_MLlam body) gnorm, gcase)
    | Gletcase(Gcase (_,i), params, annot,a,accu,bs) ->
	let (gnorm,gcase) = gdef in
	(gnorm, Int.Map.add i (params,MLmatch(annot,a,accu,bs)) gcase)
    | Gletcase _ -> assert false
    | _ -> gdef in
  let gdef = List.fold_left add_global empty_gdef stk in
  let optimize_global g = 
    match g with
    | Glet(Gconstant (prefix, c), body) ->
        Glet(Gconstant (prefix, c), optimize gdef body)
    | _ -> g in
  List.map optimize_global stk

(** Printing to ocaml **)
(* Redefine a bunch of functions in module Names to generate names
   acceptable to OCaml. *)
let string_of_id s = Unicode.ascii_of_ident (Id.to_string s)
let string_of_label l = string_of_id (Label.to_id l)

let string_of_dirpath = function
  | [] -> "_"
  | sl -> String.concat "_" (List.rev_map string_of_id sl)

(* The first letter of the file name has to be a capital to be accepted by *)
(* OCaml as a module identifier.                                           *)
let string_of_dirpath s = "N"^string_of_dirpath s

let mod_uid_of_dirpath dir = string_of_dirpath (DirPath.repr dir)

let link_info_of_dirpath dir =
  Linked (mod_uid_of_dirpath dir ^ ".")

let string_of_name x =
  match x with
    | Anonymous -> "anonymous" (* assert false *)
    | Name id -> string_of_id id

let string_of_label_def l =
  match l with
    | None -> ""
    | Some l -> string_of_label l

(* Relativization of module paths *)
let rec list_of_mp acc = function
  | MPdot (mp,l) -> list_of_mp (string_of_label l::acc) mp
  | MPfile dp ->
      let dp = DirPath.repr dp in
      string_of_dirpath dp :: acc
  | MPbound mbid -> ("X"^string_of_id (MBId.to_id mbid))::acc

let list_of_mp mp = list_of_mp [] mp

let string_of_kn kn =
  let (mp,dp,l) = KerName.repr kn in
  let mp = list_of_mp mp in
  String.concat "_" mp ^ "_" ^ string_of_label l

let string_of_con c = string_of_kn (Constant.user c)
let string_of_mind mind = string_of_kn (MutInd.user mind)

let string_of_gname g =
  match g with
  | Gind (prefix, (mind, i)) ->
      Format.sprintf "%sindaccu_%s_%i" prefix (string_of_mind mind) i
  | Gconstruct (prefix, ((mind, i), j)) ->
      Format.sprintf "%sconstruct_%s_%i_%i" prefix (string_of_mind mind) i (j-1)
  | Gconstant (prefix, c) ->
      Format.sprintf "%sconst_%s" prefix (string_of_con c)
  | Gproj (prefix, (mind, n), i) ->
      Format.sprintf "%sproj_%s_%i_%i" prefix (string_of_mind mind) n i
  | Gcase (l,i) ->
      Format.sprintf "case_%s_%i" (string_of_label_def l) i
  | Gpred (l,i) ->
      Format.sprintf "pred_%s_%i" (string_of_label_def l) i
  | Gfixtype (l,i) ->
      Format.sprintf "fixtype_%s_%i" (string_of_label_def l) i
  | Gnorm (l,i) ->
      Format.sprintf "norm_%s_%i" (string_of_label_def l) i
  | Ginternal s -> Format.sprintf "%s" s
  | Gnormtbl (l,i) -> 
      Format.sprintf "normtbl_%s_%i" (string_of_label_def l) i
  | Grel i ->
      Format.sprintf "rel_%i" i
  | Gnamed id ->
      Format.sprintf "named_%s" (string_of_id id)

let pp_gname fmt g =
  Format.fprintf fmt "%s" (string_of_gname g)

let pp_lname fmt ln =
  Format.fprintf fmt "x_%s_%i" (string_of_name ln.lname) ln.luid

let pp_ldecls fmt ids =
  let len = Array.length ids in
  for i = 0 to len - 1 do
    Format.fprintf fmt " (%a : Nativevalues.t)" pp_lname ids.(i)
  done

let string_of_construct prefix ((mind,i),j) =
  let id = Format.sprintf "Construct_%s_%i_%i" (string_of_mind mind) i (j-1) in
  prefix ^ id
   
let pp_int fmt i =
  if i < 0 then Format.fprintf fmt "(%i)" i else Format.fprintf fmt "%i" i

let pp_mllam fmt l =

  let rec pp_mllam fmt l =
    match l with
    | MLlocal ln -> Format.fprintf fmt "@[%a@]" pp_lname ln
    | MLglobal g -> Format.fprintf fmt "@[%a@]" pp_gname g
    | MLprimitive p -> Format.fprintf fmt "@[%a@]" pp_primitive p
    | MLlam(ids,body) ->
	Format.fprintf fmt "@[(fun%a@ ->@\n %a)@]"
	  pp_ldecls ids pp_mllam body
    | MLletrec(defs, body) ->
	Format.fprintf fmt "@[%a@ in@\n%a@]" pp_letrec defs 
	  pp_mllam body
    | MLlet(id,def,body) ->
	Format.fprintf fmt "@[(let@ %a@ =@\n %a@ in@\n%a)@]"
          pp_lname id pp_mllam def pp_mllam body
    | MLapp(f, args) ->
	Format.fprintf fmt "@[%a@ %a@]" pp_mllam f (pp_args true) args
    | MLif(t,l1,l2) ->
	Format.fprintf fmt "@[(if %a then@\n  %a@\nelse@\n  %a)@]"
	  pp_mllam t pp_mllam l1 pp_mllam l2 
    | MLmatch (annot, c, accu_br, br) ->
	  let mind,i = annot.asw_ind in
      let prefix = annot.asw_prefix in
	  let accu = Format.sprintf "%sAccu_%s_%i" prefix (string_of_mind mind) i in
	  Format.fprintf fmt 
	    "@[begin match Obj.magic (%a) with@\n| %s _ ->@\n  %a@\n%aend@]"
	  pp_mllam c accu pp_mllam accu_br (pp_branches prefix) br
	  
    | MLconstruct(prefix,c,args) ->
        Format.fprintf fmt "@[(Obj.magic (%s%a) : Nativevalues.t)@]" 
          (string_of_construct prefix c) pp_cargs args
    | MLint i -> pp_int fmt i
    | MLuint i -> Format.fprintf fmt "(Uint31.of_int %a)" pp_int (Uint31.to_int i)
    | MLsetref (s, body) ->
	Format.fprintf fmt "@[%s@ :=@\n %a@]" s pp_mllam body
    | MLsequence(l1,l2) ->
	Format.fprintf fmt "@[%a;@\n%a@]" pp_mllam l1 pp_mllam l2
    | MLarray arr ->
       let len = Array.length arr in
       Format.fprintf fmt "@[[|";
       if 0 < len then begin
	 for i = 0 to len - 2 do
           Format.fprintf fmt "%a;" pp_mllam arr.(i)
	 done;
         pp_mllam fmt arr.(len-1)
       end;
       Format.fprintf fmt "|]@]"
    | MLisaccu (prefix, (mind, i), c) ->
        let accu = Format.sprintf "%sAccu_%s_%i" prefix (string_of_mind mind) i in
        Format.fprintf fmt
          "@[begin match Obj.magic (%a) with@\n| %s _ ->@\n  true@\n| _ ->@\n  false@\nend@]"
        pp_mllam c accu

  and pp_letrec fmt defs =
    let len = Array.length defs in
    let pp_one_rec (fn, argsn, body) =
      Format.fprintf fmt "%a%a =@\n  %a"
	pp_lname fn 
	pp_ldecls argsn pp_mllam body in
    Format.fprintf fmt "@[let rec ";
    pp_one_rec defs.(0);
    for i = 1 to len - 1 do
      Format.fprintf fmt "@\nand ";
      pp_one_rec defs.(i)
    done;

  and pp_blam fmt l =
    match l with
    | MLprimitive (Mk_prod | Mk_sort) (* FIXME: why this special case? *)
    | MLlam _ | MLletrec _ | MLlet _ | MLapp _ | MLif _ ->
	Format.fprintf fmt "(%a)" pp_mllam l
    | MLconstruct(_,_,args) when Array.length args > 0 ->
	Format.fprintf fmt "(%a)" pp_mllam l
    | _ -> pp_mllam fmt l

  and pp_args sep fmt args =
    let sep = if sep then " " else "," in
    let len = Array.length args in
    if len > 0 then begin
      Format.fprintf fmt "%a" pp_blam args.(0);
      for i = 1 to len - 1 do
	Format.fprintf fmt "%s%a" sep pp_blam args.(i)
      done
    end

  and pp_cargs fmt args =
    let len = Array.length args in
    match len with
    | 0 -> ()
    | 1 -> Format.fprintf fmt " %a" pp_blam args.(0)
    | _ -> Format.fprintf fmt "(%a)" (pp_args false) args

  and pp_cparam fmt param = 
    match param with
    | Some l -> pp_mllam fmt (MLlocal l)
    | None -> Format.fprintf fmt "_"

  and pp_cparams fmt params =
    let len = Array.length params in
    match len with
    | 0 -> ()
    | 1 -> Format.fprintf fmt " %a" pp_cparam params.(0)
    | _ -> 
	let aux fmt params =
	  Format.fprintf fmt "%a" pp_cparam params.(0);
	  for i = 1 to len - 1 do
	    Format.fprintf fmt ",%a" pp_cparam params.(i)
	  done in 
	Format.fprintf fmt "(%a)" aux params

  and pp_branches prefix fmt bs =
    let pp_branch (cargs,body) =
      let pp_c fmt (cn,args) = 
        Format.fprintf fmt "| %s%a " 
      (string_of_construct prefix cn) pp_cparams args in
      let rec pp_cargs fmt cargs =
        match cargs with
    | [] -> ()
    | cargs::cargs' -> 
        Format.fprintf fmt "%a%a" pp_c cargs pp_cargs cargs' in
      Format.fprintf fmt "%a ->@\n  %a@\n" 
    pp_cargs cargs pp_mllam body
      in
    Array.iter pp_branch bs

  and pp_primitive fmt = function
    | Mk_prod -> Format.fprintf fmt "mk_prod_accu" 
    | Mk_sort -> Format.fprintf fmt "mk_sort_accu"
    | Mk_ind -> Format.fprintf fmt "mk_ind_accu"
    | Mk_const -> Format.fprintf fmt "mk_constant_accu"
    | Mk_sw -> Format.fprintf fmt "mk_sw_accu"
    | Mk_fix(rec_pos,start) -> 
	let pp_rec_pos fmt rec_pos = 
	  Format.fprintf fmt "@[[| %i" rec_pos.(0);
	  for i = 1 to Array.length rec_pos - 1 do
	    Format.fprintf fmt "; %i" rec_pos.(i) 
	  done;
	  Format.fprintf fmt " |]@]" in
	Format.fprintf fmt "mk_fix_accu %a %i" pp_rec_pos rec_pos start
    | Mk_cofix(start) -> Format.fprintf fmt "mk_cofix_accu %i" start
    | Mk_rel i -> Format.fprintf fmt "mk_rel_accu %i" i
    | Mk_var id ->
        Format.fprintf fmt "mk_var_accu (Names.Id.of_string \"%s\")" (string_of_id id)
    | Mk_proj -> Format.fprintf fmt "mk_proj_accu"
    | Is_int -> Format.fprintf fmt "is_int"
    | Cast_accu -> Format.fprintf fmt "cast_accu"
    | Upd_cofix -> Format.fprintf fmt "upd_cofix"
    | Force_cofix -> Format.fprintf fmt "force_cofix"
    | Mk_uint -> Format.fprintf fmt "mk_uint"
    | Mk_int -> Format.fprintf fmt "mk_int"
    | Mk_bool -> Format.fprintf fmt "mk_bool"
    | Val_to_int -> Format.fprintf fmt "val_to_int"
    | Mk_I31_accu -> Format.fprintf fmt "mk_I31_accu"
    | Decomp_uint -> Format.fprintf fmt "decomp_uint"
    | Mk_meta -> Format.fprintf fmt "mk_meta_accu"
    | Mk_evar -> Format.fprintf fmt "mk_evar_accu"
    | MLand -> Format.fprintf fmt "(&&)"
    | MLle -> Format.fprintf fmt "(<=)"
    | MLlt -> Format.fprintf fmt "(<)"
    | MLinteq -> Format.fprintf fmt "(==)"
    | MLlsl -> Format.fprintf fmt "(lsl)"
    | MLlsr -> Format.fprintf fmt "(lsr)"
    | MLland -> Format.fprintf fmt "(land)"
    | MLlor -> Format.fprintf fmt "(lor)"
    | MLlxor -> Format.fprintf fmt "(lxor)"
    | MLadd -> Format.fprintf fmt "(+)"
    | MLsub -> Format.fprintf fmt "(-)"
    | MLmul -> Format.fprintf fmt "( * )"
    | MLmagic -> Format.fprintf fmt "Obj.magic"
    | MLarrayget -> Format.fprintf fmt "Array.get"
    | Mk_empty_instance -> Format.fprintf fmt "Univ.Instance.empty"
    | Coq_primitive (op,None) ->
       Format.fprintf fmt "no_check_%s" (CPrimitives.to_string op)
    | Coq_primitive (op, Some (prefix,kn)) ->
        Format.fprintf fmt "%s %a" (CPrimitives.to_string op)
		       pp_mllam (MLglobal (Gconstant (prefix, kn)))
  in
  Format.fprintf fmt "@[%a@]" pp_mllam l
  
let pp_array fmt t =
  let len = Array.length t in
  Format.fprintf fmt "@[[|";
  for i = 0 to len - 2 do
    Format.fprintf fmt "%a; " pp_mllam t.(i)
  done;
  if len > 0 then
    Format.fprintf fmt "%a" pp_mllam t.(len - 1);
  Format.fprintf fmt "|]@]"
  
let pp_global fmt g =
  match g with
  | Glet (gn, c) ->
      let ids, c = decompose_MLlam c in
      Format.fprintf fmt "@[let %a%a =@\n  %a@]@\n@." pp_gname gn 
	pp_ldecls ids
	pp_mllam c
  | Gopen s ->
      Format.fprintf fmt "@[open %s@]@." s
  | Gtype ((mind, i), lar) ->
      let l = string_of_mind mind in
      let rec aux s ar = 
	if Int.equal ar 0 then s else aux (s^" * Nativevalues.t") (ar-1) in
      let pp_const_sig i fmt j ar =
        let sig_str = if ar > 0 then aux "of Nativevalues.t" (ar-1) else "" in
        Format.fprintf fmt "  | Construct_%s_%i_%i %s@\n" l i j sig_str
      in
      let pp_const_sigs i fmt lar =
        Format.fprintf fmt "  | Accu_%s_%i of Nativevalues.t@\n" l i;
        Array.iteri (pp_const_sig i fmt) lar
      in
      Format.fprintf fmt "@[type ind_%s_%i =@\n%a@]@\n@." l i (pp_const_sigs i) lar
  | Gtblfixtype (g, params, t) ->
      Format.fprintf fmt "@[let %a %a =@\n  %a@]@\n@." pp_gname g
	pp_ldecls params pp_array t
  | Gtblnorm (g, params, t) ->
      Format.fprintf fmt "@[let %a %a =@\n  %a@]@\n@." pp_gname g
	pp_ldecls params pp_array t 
  | Gletcase(gn,params,annot,a,accu,bs) ->
      Format.fprintf fmt "@[(* Hash = %i *)@\nlet rec %a %a =@\n  %a@]@\n@."
      (hash_global g)
	pp_gname gn pp_ldecls params 
	pp_mllam (MLmatch(annot,a,accu,bs))
  | Gcomment s ->
      Format.fprintf fmt "@[(* %s *)@]@." s

(** Compilation of elements in environment **)
let rec compile_with_fv env sigma univ auxdefs l t =
  let (auxdefs,(fv_named,fv_rel),ml) = mllambda_of_lambda univ auxdefs l t in
  if List.is_empty fv_named && List.is_empty fv_rel then (auxdefs,ml)
  else apply_fv env sigma univ (fv_named,fv_rel) auxdefs ml

and apply_fv env sigma univ (fv_named,fv_rel) auxdefs ml =
  let get_rel_val (n,_) auxdefs =
    (*
    match !(lookup_rel_native_val n env) with
    | NVKnone ->
    *)
        compile_rel env sigma univ auxdefs n
(*    | NVKvalue (v,d) -> assert false *)
  in
  let get_named_val (id,_) auxdefs =
    (*
    match !(lookup_named_native_val id env) with
    | NVKnone ->
        *)
        compile_named env sigma univ auxdefs id
(*    | NVKvalue (v,d) -> assert false *)
  in
  let auxdefs = List.fold_right get_rel_val fv_rel auxdefs in
  let auxdefs = List.fold_right get_named_val fv_named auxdefs in
  let lvl = Context.Rel.length (rel_context env) in
  let fv_rel = List.map (fun (n,_) -> MLglobal (Grel (lvl-n))) fv_rel in
  let fv_named = List.map (fun (id,_) -> MLglobal (Gnamed id)) fv_named in
  let aux_name = fresh_lname Anonymous in
  auxdefs, MLlet(aux_name, ml, mkMLapp (MLlocal aux_name) (Array.of_list (fv_rel@fv_named)))

and compile_rel env sigma univ auxdefs n =
  let open Context.Rel.Declaration in
  let decl = lookup_rel n env in
  let n = List.length (rel_context env) - n in
  match decl with
  | LocalDef (_,t,_) ->
      let code = lambda_of_constr env sigma t in
      let auxdefs,code = compile_with_fv env sigma univ auxdefs None code in
      Glet(Grel n, code)::auxdefs
  | LocalAssum _ ->
      Glet(Grel n, MLprimitive (Mk_rel n))::auxdefs

and compile_named env sigma univ auxdefs id =
  let open Context.Named.Declaration in
  match lookup_named id env with
  | LocalDef (_,t,_) ->
      let code = lambda_of_constr env sigma t in
      let auxdefs,code = compile_with_fv env sigma univ auxdefs None code in
      Glet(Gnamed id, code)::auxdefs
  | LocalAssum _ ->
      Glet(Gnamed id, MLprimitive (Mk_var id))::auxdefs

let compile_constant env sigma prefix ~interactive con cb =
     let no_univs =
       match cb.const_universes with
       | Monomorphic_const _ -> true
       | Polymorphic_const ctx -> Int.equal (Univ.AUContext.size ctx) 0
     in
    begin match cb.const_body with
    | Def t ->
      let t = Mod_subst.force_constr t in
      let code = lambda_of_constr env sigma t in
      if !Flags.debug then Feedback.msg_debug (Pp.str "Generated lambda code");
      let is_lazy = is_lazy env prefix t in
      let code = if is_lazy then mk_lazy code else code in
      let name =
        if interactive then LinkedInteractive prefix
        else Linked prefix
      in
      let l = Constant.label con in
      let auxdefs,code =
	if no_univs then compile_with_fv env sigma None [] (Some l) code
	else
	  let univ = fresh_univ () in
	  let (auxdefs,code) = compile_with_fv env sigma (Some univ) [] (Some l) code in
          (auxdefs,mkMLlam [|univ|] code)
      in
      if !Flags.debug then Feedback.msg_debug (Pp.str "Generated mllambda code");
      let code =
        optimize_stk (Glet(Gconstant ("", con),code)::auxdefs)
      in
      if !Flags.debug then Feedback.msg_debug (Pp.str "Optimized mllambda code");
      code, name
    | _ -> 
        let i = push_symbol (SymbConst con) in
	let args =
	  if no_univs then [|get_const_code i; MLarray [||]|]
	  else [|get_const_code i|]
	in
	(*
	let t = mkMLlam [|univ|] (mkMLapp (MLprimitive Mk_const)
	 *)
        [Glet(Gconstant ("", con), mkMLapp (MLprimitive Mk_const) args)],
	  if interactive then LinkedInteractive prefix
	  else Linked prefix
    end

module StringOrd = struct type t = string let compare = String.compare end
module StringSet = Set.Make(StringOrd)

let loaded_native_files = ref StringSet.empty

let is_loaded_native_file s = StringSet.mem s !loaded_native_files

let register_native_file s =
  loaded_native_files := StringSet.add s !loaded_native_files

let is_code_loaded ~interactive name =
  match !name with
  | NotLinked -> false
  | LinkedInteractive s ->
      if (interactive && is_loaded_native_file s) then true
      else (name := NotLinked; false)
  | Linked s ->
      if is_loaded_native_file s then true
      else (name := NotLinked; false)

let param_name = Name (Id.of_string "params")
let arg_name = Name (Id.of_string "arg")

let compile_mind mb mind stack =
  let u = Declareops.inductive_polymorphic_context mb in
  (** Generate data for every block *)
  let f i stack ob =
    let ind = (mind, i) in
    let gtype = Gtype(ind, Array.map snd ob.mind_reloc_tbl) in
    let j = push_symbol (SymbInd ind) in
    let name = Gind ("", ind) in
    let accu =
      let args =
	if Int.equal (Univ.AUContext.size u) 0 then
	  [|get_ind_code j; MLarray [||]|]
	else [|get_ind_code j|]
      in
      Glet(name, MLapp (MLprimitive Mk_ind, args))
    in
    let nparams = mb.mind_nparams in
    let params = 
      Array.init nparams (fun i -> {lname = param_name; luid = i}) in
    let add_construct j acc (_,arity) = 
      let args = Array.init arity (fun k -> {lname = arg_name; luid = k}) in 
      let c = ind, (j+1) in
	  Glet(Gconstruct ("", c),
	     mkMLlam (Array.append params args)
	       (MLconstruct("", c, Array.map (fun id -> MLlocal id) args)))::acc
    in
    let constructors = Array.fold_left_i add_construct [] ob.mind_reloc_tbl in
    let add_proj proj_arg acc pb =
      let tbl = ob.mind_reloc_tbl in
      (* Building info *)
      let ci = { ci_ind = ind; ci_npar = nparams;
                 ci_cstr_nargs = [|0|];
                 ci_cstr_ndecls = [||] (*FIXME*);
                 ci_pp_info = { ind_tags = []; cstr_tags = [||] (*FIXME*); style = RegularStyle } } in
      let asw = { asw_ind = ind; asw_prefix = ""; asw_ci = ci;
                  asw_reloc = tbl; asw_finite = true } in
      let c_uid = fresh_lname Anonymous in
      let cf_uid = fresh_lname Anonymous in
      let _, arity = tbl.(0) in
      let ci_uid = fresh_lname Anonymous in
      let cargs = Array.init arity
        (fun i -> if Int.equal i proj_arg then Some ci_uid else None)
      in
      let i = push_symbol (SymbProj (ind, j)) in
      let accu = MLapp (MLprimitive Cast_accu, [|MLlocal cf_uid|]) in
      let accu_br = MLapp (MLprimitive Mk_proj, [|get_proj_code i;accu|]) in
      let code = MLmatch(asw,MLlocal cf_uid,accu_br,[|[((ind,1),cargs)],MLlocal ci_uid|]) in
      let code = MLlet(cf_uid, mkForceCofix "" ind (MLlocal c_uid), code) in
      let gn = Gproj ("", ind, proj_arg) in
      Glet (gn, mkMLlam [|c_uid|] code) :: acc
    in
    let projs = match mb.mind_record with
    | NotRecord | FakeRecord -> []
    | PrimRecord info ->
      let _, _, pbs = info.(i) in
      Array.fold_left_i add_proj [] pbs
    in
    projs @ constructors @ gtype :: accu :: stack
  in
  Array.fold_left_i f stack mb.mind_packets

type code_location_update =
    link_info ref * link_info
type code_location_updates =
  code_location_update Mindmap_env.t * code_location_update Cmap_env.t

type linkable_code = global list * code_location_updates

let empty_updates = Mindmap_env.empty, Cmap_env.empty

let compile_mind_deps env prefix ~interactive
    (comp_stack, (mind_updates, const_updates) as init) mind =
  let mib,nameref = lookup_mind_key mind env in
  if is_code_loaded ~interactive nameref
    || Mindmap_env.mem mind mind_updates
  then init
  else
    let comp_stack =
      compile_mind mib mind comp_stack
    in
    let name =
      if interactive then LinkedInteractive prefix
      else Linked prefix
    in
    let upd = (nameref, name) in
    let mind_updates = Mindmap_env.add mind upd mind_updates in
    (comp_stack, (mind_updates, const_updates))

(* This function compiles all necessary dependencies of t, and generates code in
   reverse order, as well as linking information updates *)
let compile_deps env sigma prefix ~interactive init t =
  let rec aux env lvl init t =
  match kind t with
  | Ind ((mind,_),u) -> compile_mind_deps env prefix ~interactive init mind
  | Const c ->
    let c,u = get_alias env c in
    let cb,(nameref,_) = lookup_constant_key c env in
    let (_, (_, const_updates)) = init in
    if is_code_loaded ~interactive nameref
    || (Cmap_env.mem c const_updates)
    then init
    else
      let comp_stack, (mind_updates, const_updates) =
        match cb.const_body with
        | Def t ->
           aux env lvl init (Mod_subst.force_constr t)
        | _ -> init
      in
      let code, name =
	compile_constant env sigma prefix ~interactive c cb
      in
      let comp_stack = code@comp_stack in
      let const_updates = Cmap_env.add c (nameref, name) const_updates in
      comp_stack, (mind_updates, const_updates)
  | Construct (((mind,_),_),u) -> compile_mind_deps env prefix ~interactive init mind
  | Proj (p,c) ->
    let init = compile_mind_deps env prefix ~interactive init (Projection.mind p) in
    aux env lvl init c
  | Case (ci, p, c, ac) ->
      let mind = fst ci.ci_ind in
      let init = compile_mind_deps env prefix ~interactive init mind in
      fold_constr_with_binders succ (aux env) lvl init t
  | Var id ->
    let open Context.Named.Declaration in
    begin match lookup_named id env with
      | LocalDef (_,t,_) ->
        aux env lvl init t
      | _ -> init
    end
  | Rel n when n > lvl ->
    let open Context.Rel.Declaration in
    let decl = lookup_rel n env in
    let env = env_of_rel n env in
    begin match decl with
    | LocalDef (_,t,_) ->
      aux env lvl init t
    | LocalAssum _ -> init
    end
  | _ -> fold_constr_with_binders succ (aux env) lvl init t
  in
  aux env 0 init t

let compile_constant_field env prefix con acc cb =
    let (gl, _) =
      compile_constant ~interactive:false env empty_evars prefix
        con cb
    in
    gl@acc

let compile_mind_field mp l acc mb =
  let mind = MutInd.make2 mp l in
  compile_mind mb mind acc

let mk_open s = Gopen s

let mk_internal_let s code =
  Glet(Ginternal s, code)

(* ML Code for conversion function *)
let mk_conv_code env sigma prefix t1 t2 =
  clear_symbols ();
  clear_global_tbl ();
  let gl, (mind_updates, const_updates) =
    let init = ([], empty_updates) in
    compile_deps env sigma prefix ~interactive:true init t1
  in
  let gl, (mind_updates, const_updates) =
    let init = (gl, (mind_updates, const_updates)) in
    compile_deps env sigma prefix ~interactive:true init t2
  in
  let code1 = lambda_of_constr env sigma t1 in
  let code2 = lambda_of_constr env sigma t2 in
  let (gl,code1) = compile_with_fv env sigma None gl None code1 in
  let (gl,code2) = compile_with_fv env sigma None gl None code2 in
  let t1 = mk_internal_let "t1" code1 in
  let t2 = mk_internal_let "t2" code2 in
  let g1 = MLglobal (Ginternal "t1") in
  let g2 = MLglobal (Ginternal "t2") in
  let setref1 = Glet(Ginternal "_", MLsetref("rt1",g1)) in
  let setref2 = Glet(Ginternal "_", MLsetref("rt2",g2)) in
  let gl = List.rev (setref2 :: setref1 :: t2 :: t1 :: gl) in
  let header = Glet(Ginternal "symbols_tbl",
    MLapp (MLglobal (Ginternal "get_symbols"),
      [|MLglobal (Ginternal "()")|])) in
  header::gl, (mind_updates, const_updates)

let mk_norm_code env sigma prefix t =
  clear_symbols ();
  clear_global_tbl ();
  let gl, (mind_updates, const_updates) =
    let init = ([], empty_updates) in
    compile_deps env sigma prefix ~interactive:true init t
  in
  let code = lambda_of_constr env sigma t in
  let (gl,code) = compile_with_fv env sigma None gl None code in
  let t1 = mk_internal_let "t1" code in
  let g1 = MLglobal (Ginternal "t1") in
  let setref = Glet(Ginternal "_", MLsetref("rt1",g1)) in
  let gl = List.rev (setref :: t1 :: gl) in
  let header = Glet(Ginternal "symbols_tbl",
    MLapp (MLglobal (Ginternal "get_symbols"),
      [|MLglobal (Ginternal "()")|])) in
  header::gl, (mind_updates, const_updates)

let mk_library_header dir =
  let libname = Format.sprintf "(str_decode \"%s\")" (str_encode dir) in
  [Glet(Ginternal "symbols_tbl",
    MLapp (MLglobal (Ginternal "get_library_native_symbols"),
    [|MLglobal (Ginternal libname)|]))]

let update_location (r,v) = r := v

let update_locations (ind_updates,const_updates) =
  Mindmap_env.iter (fun _ -> update_location) ind_updates;
  Cmap_env.iter (fun _ -> update_location) const_updates

let add_header_comment mlcode s =
  Gcomment s :: mlcode

(* vim: set filetype=ocaml foldmethod=marker: *)