ocaml/asmcomp/cmmgen.ml

(***********************************************************************)
(*                                                                     *)
(*                           Objective Caml                            *)
(*                                                                     *)
(*            Xavier Leroy, projet Cristal, INRIA Rocquencourt         *)
(*                                                                     *)
(*  Copyright 1996 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the Q Public License version 1.0.               *)
(*                                                                     *)
(***********************************************************************)

(* $Id$ *)

(* Translation from closed lambda to C-- *)

open Misc
open Arch
open Asttypes
open Primitive
open Types
open Lambda
open Clambda
open Cmm

(* Local binding of complex expressions *)

let bind name arg fn =
  match arg with
    Cvar _ | Cconst_int _ | Cconst_natint _ | Cconst_symbol _ 
  | Cconst_pointer _ | Cconst_natpointer _ -> fn arg
  | _ -> let id = Ident.create name in Clet(id, arg, fn (Cvar id))

let bind_nonvar name arg fn =
  match arg with
    Cconst_int _ | Cconst_natint _ | Cconst_symbol _
  | Cconst_pointer _ | Cconst_natpointer _ -> fn arg
  | _ -> let id = Ident.create name in Clet(id, arg, fn (Cvar id))

(* Block headers. Meaning of the tag field:
       0 - 248: regular blocks
       249: infix closure
       250: closures
       251: abstract
       252: string
       253: float
       254: float array
       255: finalized *)

let float_tag = Cconst_int 253
let floatarray_tag = Cconst_int 254

let block_header tag sz =
  Nativeint.add (Nativeint.shift_left (Nativeint.of_int sz) 10)
                (Nativeint.of_int tag)
let closure_header sz = block_header 250 sz
let infix_header ofs = block_header 249 ofs
let float_header = block_header 253 (size_float / size_addr)
let floatarray_header len = block_header 254 (len * size_float / size_addr)
let string_header len = block_header 252 ((len + size_addr) / size_addr)
let boxedint_header = block_header 255 2

let alloc_block_header tag sz = Cconst_natint(block_header tag sz)
let alloc_float_header = Cconst_natint(float_header)
let alloc_floatarray_header len = Cconst_natint(floatarray_header len)
let alloc_closure_header sz = Cconst_natint(closure_header sz)
let alloc_infix_header ofs = Cconst_natint(infix_header ofs)
let alloc_boxedint_header = Cconst_natint(boxedint_header)

(* Integers *)

let max_repr_int = max_int asr 1
let min_repr_int = min_int asr 1

let int_const n =
  if n <= max_repr_int && n >= min_repr_int
  then Cconst_int((n lsl 1) + 1)
  else Cconst_natint(Nativeint.add
                       (Nativeint.shift_left (Nativeint.of_int n) 1)
                       Nativeint.one)

let add_const c n =
  if n = 0 then c else Cop(Caddi, [c; Cconst_int n])

let incr_int = function
    Cconst_int n when n < max_int -> Cconst_int(n+1)
  | Cop(Caddi, [c; Cconst_int n]) when n < max_int -> add_const c (n + 1)
  | c -> add_const c 1

let decr_int = function
    Cconst_int n when n > min_int -> Cconst_int(n-1)
  | Cop(Caddi, [c; Cconst_int n]) when n > min_int -> add_const c (n - 1)
  | c -> add_const c (-1)

let add_int c1 c2 =
  match (c1, c2) with
    (Cop(Caddi, [c1; Cconst_int n1]),
     Cop(Caddi, [c2; Cconst_int n2])) when no_overflow_add n1 n2 ->
      add_const (Cop(Caddi, [c1; c2])) (n1 + n2)
  | (Cop(Caddi, [c1; Cconst_int n1]), c2) ->
      add_const (Cop(Caddi, [c1; c2])) n1
  | (c1, Cop(Caddi, [c2; Cconst_int n2])) ->
      add_const (Cop(Caddi, [c1; c2])) n2
  | (Cconst_int _, _) ->
      Cop(Caddi, [c2; c1])
  | (_, _) ->
      Cop(Caddi, [c1; c2])

let sub_int c1 c2 =
  match (c1, c2) with
    (Cop(Caddi, [c1; Cconst_int n1]),
     Cop(Caddi, [c2; Cconst_int n2])) when no_overflow_sub n1 n2 ->
      add_const (Cop(Csubi, [c1; c2])) (n1 - n2)
  | (Cop(Caddi, [c1; Cconst_int n1]), c2) ->
      add_const (Cop(Csubi, [c1; c2])) n1
  | (c1, Cop(Caddi, [c2; Cconst_int n2])) when n2 <> min_int ->
      add_const (Cop(Csubi, [c1; c2])) (-n2)
  | (c1, Cconst_int n) when n <> min_int ->
      add_const c1 (-n)
  | (c1, c2) ->
      Cop(Csubi, [c1; c2])

let mul_int c1 c2 =
  match (c1, c2) with
    (Cconst_int 0, _) -> c1
  | (Cconst_int 1, _) -> c2
  | (_, Cconst_int 0) -> c2
  | (_, Cconst_int 1) -> c1
  | (_, _) -> Cop(Cmuli, [c1; c2])

let tag_int = function
    Cconst_int n -> int_const n
  | c -> Cop(Caddi, [Cop(Clsl, [c; Cconst_int 1]); Cconst_int 1])

let force_tag_int = function
    Cconst_int n -> int_const n
  | c -> Cop(Cor, [Cop(Clsl, [c; Cconst_int 1]); Cconst_int 1])

let untag_int = function
    Cconst_int n -> Cconst_int(n asr 1)
  | Cop(Caddi, [Cop(Clsl, [c; Cconst_int 1]); Cconst_int 1]) -> c
  | Cop(Cor, [Cop(Casr, [c; Cconst_int n]); Cconst_int 1])
    when n > 0 && n < size_int * 8 ->
      Cop(Casr, [c; Cconst_int (n+1)])
  | Cop(Cor, [Cop(Clsr, [c; Cconst_int n]); Cconst_int 1])
    when n > 0 && n < size_int * 8 ->
      Cop(Clsr, [c; Cconst_int (n+1)])
  | Cop(Cor, [c; Cconst_int 1]) -> Cop(Casr, [c; Cconst_int 1])
  | c -> Cop(Casr, [c; Cconst_int 1])

let lsl_int c1 c2 =
  match (c1, c2) with
    (Cop(Clsl, [c; Cconst_int n1]), Cconst_int n2)
    when n1 > 0 && n2 > 0 && n1 + n2 < size_int * 8 ->
      Cop(Clsl, [c; Cconst_int (n1 + n2)])
  | (_, _) ->
      Cop(Clsl, [c1; c2])

let ignore_low_bit_int = function
    Cop(Caddi, [(Cop(Clsl, [_; Cconst_int 1]) as c); Cconst_int 1]) -> c
  | Cop(Cor, [c; Cconst_int 1]) -> c
  | c -> c

(* Bool *)

let test_bool = function
    Cop(Caddi, [Cop(Clsl, [c; Cconst_int 1]); Cconst_int 1]) -> c
  | Cop(Clsl, [c; Cconst_int 1]) -> c
  | c -> Cop(Ccmpi Cne, [c; Cconst_int 1])

(* Float *)

let box_float c = Cop(Calloc, [alloc_float_header; c])

let unbox_float = function
    Cop(Calloc, [header; c]) -> c
  | c -> Cop(Cload Double_u, [c])

(* Unit *)

let return_unit c = Csequence(c, Cconst_pointer 1)

let rec remove_unit = function
    Cconst_pointer 1 -> Ctuple []
  | Csequence(c, Cconst_pointer 1) -> c
  | Csequence(c1, c2) ->
      Csequence(c1, remove_unit c2)
  | Cifthenelse(cond, ifso, ifnot) ->
      Cifthenelse(cond, remove_unit ifso, remove_unit ifnot)
  | Cswitch(sel, index, cases) ->
      Cswitch(sel, index, Array.map remove_unit cases)
  | Ccatch(io, ids, body, handler) ->
      Ccatch(io, ids, remove_unit body, remove_unit handler)
  | Ctrywith(body, exn, handler) ->
      Ctrywith(remove_unit body, exn, remove_unit handler)
  | Clet(id, c1, c2) ->
      Clet(id, c1, remove_unit c2)
  | Cop(Capply mty, args) ->
      Cop(Capply typ_void, args)
  | Cop(Cextcall(proc, mty, alloc), args) ->
      Cop(Cextcall(proc, typ_void, alloc), args)
  | Cexit (_,_) as c -> c
  | Ctuple [] as c -> c
  | c -> Csequence(c, Ctuple [])

(* Access to block fields *)

let field_address ptr n =
  if n = 0
  then ptr
  else Cop(Cadda, [ptr; Cconst_int(n * size_addr)])

let get_field ptr n =
  Cop(Cload Word, [field_address ptr n])

let set_field ptr n newval =
  Cop(Cstore Word, [field_address ptr n; newval])

let header ptr =
  Cop(Cload Word, [Cop(Cadda, [ptr; Cconst_int(-size_int)])])

let tag_offset =
  if big_endian then -1 else -size_int

let get_tag ptr =
  if Proc.word_addressed then           (* If byte loads are slow *)
    Cop(Cand, [header ptr; Cconst_int 255])
  else                                  (* If byte loads are efficient *)
    Cop(Cload Byte_unsigned,
        [Cop(Cadda, [ptr; Cconst_int(tag_offset)])])

(* Array indexing *)

let log2_size_addr = Misc.log2 size_addr
let log2_size_float = Misc.log2 size_float

let wordsize_shift = 9
let numfloat_shift = 9 + log2_size_float - log2_size_addr

let is_addr_array_hdr hdr =
  Cop(Ccmpi Cne, [Cop(Cand, [hdr; Cconst_int 255]); floatarray_tag])

let is_addr_array_ptr ptr =
  Cop(Ccmpi Cne, [get_tag ptr; floatarray_tag])

let addr_array_length hdr = Cop(Clsr, [hdr; Cconst_int wordsize_shift])
let float_array_length hdr = Cop(Clsr, [hdr; Cconst_int numfloat_shift])

let lsl_const c n =
  Cop(Clsl, [c; Cconst_int n])

let array_indexing log2size ptr ofs =
  match ofs with
    Cconst_int n ->
      let i = n asr 1 in
      if i = 0 then ptr else Cop(Cadda, [ptr; Cconst_int(i lsl log2size)])
  | Cop(Caddi, [Cop(Clsl, [c; Cconst_int 1]); Cconst_int 1]) ->
      Cop(Cadda, [ptr; lsl_const c log2size])
  | Cop(Caddi, [c; Cconst_int n]) ->
      Cop(Cadda, [Cop(Cadda, [ptr; lsl_const c (log2size - 1)]);
                   Cconst_int((n-1) lsl (log2size - 1))])
  | _ ->
      Cop(Cadda, [Cop(Cadda, [ptr; lsl_const ofs (log2size - 1)]);
                   Cconst_int((-1) lsl (log2size - 1))])

let addr_array_ref arr ofs =
  Cop(Cload Word, [array_indexing log2_size_addr arr ofs])
let unboxed_float_array_ref arr ofs =
  Cop(Cload Double_u, [array_indexing log2_size_float arr ofs])
let float_array_ref arr ofs =
  box_float(unboxed_float_array_ref arr ofs)

let addr_array_set arr ofs newval =
  Cop(Cextcall("modify", typ_void, false),
      [array_indexing log2_size_addr arr ofs; newval])
let int_array_set arr ofs newval =
  Cop(Cstore Word, [array_indexing log2_size_addr arr ofs; newval])
let float_array_set arr ofs newval =
  Cop(Cstore Double_u, [array_indexing log2_size_float arr ofs; newval])

(* String length *)

let string_length exp =
  bind "str" exp (fun str ->
    let tmp_var = Ident.create "tmp" in
    Clet(tmp_var,
         Cop(Csubi,
             [Cop(Clsl,
                   [Cop(Clsr, [header str; Cconst_int 10]);
                     Cconst_int log2_size_addr]);
              Cconst_int 1]),
         Cop(Csubi,
             [Cvar tmp_var;
               Cop(Cload Byte_unsigned,
                     [Cop(Cadda, [str; Cvar tmp_var])])])))

(* Message sending *)

let lookup_label obj lab =
  bind "lab" lab (fun lab ->
    let table = Cop (Cload Word, [obj]) in
    let buck_index = Cop(Clsr, [lab; Cconst_int 16]) in
    let bucket = Cop(Cload Word, [Cop (Cadda, [table; buck_index])]) in
    let item_index = Cop(Cand, [lab; Cconst_int (255 * size_addr)]) in
    Cop (Cload Word, [Cop (Cadda, [bucket; item_index])]))

(* To compile "let rec" over values *)

let fundecls_size fundecls =
  let sz = ref (-1) in
  List.iter
    (fun (label, arity, params, body) ->
      sz := !sz + 1 + (if arity = 1 then 2 else 3))
    fundecls;
  !sz

let rec expr_size = function
    Uclosure(fundecls, clos_vars) ->
      fundecls_size fundecls + List.length clos_vars
  | Uprim(Pmakeblock(tag, mut), args) ->
      List.length args
  | Uprim(Pmakearray(Paddrarray | Pintarray), args) ->
      List.length args
  | Ulet(id, exp, body) ->
      expr_size body
  | Uletrec(bindings, body) ->
      expr_size body
  | Usequence(exp, exp') ->
      expr_size exp'
  | _ ->
      fatal_error "Cmmgen.expr_size"

(* Record application and currying functions *)

let apply_function n =
  Compilenv.need_apply_fun n; "caml_apply" ^ string_of_int n
let curry_function n =
  Compilenv.need_curry_fun n;
  if n >= 0
  then "caml_curry" ^ string_of_int n
  else "caml_tuplify" ^ string_of_int (-n)

(* Comparisons *)

let transl_comparison = function
    Lambda.Ceq -> Ceq
  | Lambda.Cneq -> Cne
  | Lambda.Cge -> Cge
  | Lambda.Cgt -> Cgt
  | Lambda.Cle -> Cle
  | Lambda.Clt -> Clt

(* Translate structured constants *)

let const_label = ref 0

let new_const_label () =
  incr const_label;
  !const_label

let new_const_symbol () =
  incr const_label;
  Compilenv.current_unit_name () ^ "_" ^ string_of_int !const_label

let structured_constants = ref ([] : (string * structured_constant) list)

let transl_constant = function
    Const_base(Const_int n) ->
      int_const n
  | Const_base(Const_char c) ->
      Cconst_int(((Char.code c) lsl 1) + 1)
  | Const_pointer n ->      
      if n <= max_repr_int && n >= min_repr_int
      then Cconst_pointer((n lsl 1) + 1)
      else Cconst_natpointer(Nativeint.add
                                (Nativeint.shift_left (Nativeint.of_int n) 1)
                                Nativeint.one)
  | cst ->
      let lbl = new_const_symbol() in
      structured_constants := (lbl, cst) :: !structured_constants;
      Cconst_symbol lbl

(* Translate constant closures *)

let constant_closures =
  ref ([] : (string * (string * int * Ident.t list * ulambda) list) list)

(* Boxed integers *)

let operations_boxed_int bi =
  match bi with Pnativeint -> "nativeint_ops"
              | Pint32 -> "int32_ops"
              | Pint64 -> "int64_ops"

let constant_boxed_ints =
  ref ([] : (string * boxed_integer * nativeint) list)

let label_constant_boxed_int bi n =
  let s = new_const_symbol() in
  constant_boxed_ints := (s, bi, n) :: !constant_boxed_ints;
  s

let box_int bi arg =
  match arg with
    Cconst_int n ->
      Cconst_symbol(label_constant_boxed_int bi (Nativeint.of_int n))
  | Cconst_natint n ->
      Cconst_symbol(label_constant_boxed_int bi n)
  | _ ->
      if bi = Pint32 && size_int = 8 && big_endian then
        let id = Ident.create "bint" in
        Clet(id, Cop(Calloc, [alloc_boxedint_header;
                              Cconst_symbol(operations_boxed_int bi);
                              Cconst_int 0]),
             Csequence(Cop(Cstore Thirtytwo_signed,
                           [Cop(Cadda, [Cvar id; Cconst_int size_addr]);
                                        arg]),
                       Cvar id))
      else
        Cop(Calloc, [alloc_boxedint_header;
                     Cconst_symbol(operations_boxed_int bi);
                     arg])

let unbox_int bi arg =
  match arg with
    Cop(Calloc, [hdr; ops; contents]) -> 
      if bi = Pint32 && size_int = 8 then
        (* Force sign-extension of low-order 32 bits *)
        Cop(Casr, [Cop(Clsl, [contents; Cconst_int 32]); Cconst_int 32])
      else
        contents
  | _ ->
      Cop(Cload(if bi = Pint32 then Thirtytwo_signed else Word),
          [Cop(Cadda, [arg; Cconst_int size_addr])])

let unbox_unsigned_int bi arg =
  match arg with
    Cop(Calloc, [hdr; ops; contents]) -> 
      if bi = Pint32 && size_int = 8 then
        (* Force zero-extension of low-order 32 bits *)
        Cop(Clsr, [Cop(Clsl, [contents; Cconst_int 32]); Cconst_int 32])
      else
        contents
  | _ ->
      Cop(Cload(if bi = Pint32 then Thirtytwo_unsigned else Word),
          [Cop(Cadda, [arg; Cconst_int size_addr])])

(* Big arrays *)

let bigarray_indexing elt_kind layout b args =
  let rec ba_indexing dim_ofs delta_ofs = function
    [] -> assert false
  | [arg] ->
      bind "idx" (untag_int arg)
        (fun idx ->
          Csequence(
            Cop(Ccheckbound, [Cop(Cload Word,[field_address b dim_ofs]); idx]),
            idx))
  | arg1 :: argl ->
      let rem = ba_indexing (dim_ofs + delta_ofs) delta_ofs argl in
      bind "idx" (untag_int arg1)
        (fun idx ->
          bind "bound" (Cop(Cload Word, [field_address b dim_ofs]))
          (fun bound ->
            Csequence(Cop(Ccheckbound, [bound; idx]),
                      add_int (mul_int rem bound) idx))) in
  let offset =
    match layout with
      Pbigarray_unknown_layout ->
        assert false
    | Pbigarray_c_layout ->
        ba_indexing (4 + List.length args) (-1) (List.rev args)
    | Pbigarray_fortran_layout ->
        ba_indexing 5 1 (List.map (fun idx -> sub_int idx (Cconst_int 2)) args)
  and elt_size =
    match elt_kind with
      Pbigarray_unknown -> assert false
    | Pbigarray_float32 -> 4
    | Pbigarray_float64 -> 8
    | Pbigarray_sint8 -> 1
    | Pbigarray_uint8 -> 1
    | Pbigarray_sint16 -> 2
    | Pbigarray_uint16 -> 2
    | Pbigarray_int32 -> 4
    | Pbigarray_int64 -> 8
    | Pbigarray_caml_int -> size_int
    | Pbigarray_native_int -> size_int in
  let byte_offset =
    if elt_size = 1
    then offset
    else Cop(Clsl, [offset; Cconst_int(log2 elt_size)]) in
  Cop(Cadda, [Cop(Cload Word, [field_address b 1]); byte_offset])

let bigarray_word_kind = function
    Pbigarray_unknown -> assert false
  | Pbigarray_float32 -> Single
  | Pbigarray_float64 -> Double
  | Pbigarray_sint8 -> Byte_signed
  | Pbigarray_uint8 -> Byte_unsigned
  | Pbigarray_sint16 -> Sixteen_signed
  | Pbigarray_uint16 -> Sixteen_unsigned
  | Pbigarray_int32 -> Thirtytwo_signed
  | Pbigarray_int64 -> Word
  | Pbigarray_caml_int -> Word
  | Pbigarray_native_int -> Word

let bigarray_get elt_kind layout b args =
  Cop(Cload (bigarray_word_kind elt_kind),
      [bigarray_indexing elt_kind layout b args])

let bigarray_set elt_kind layout b args newval =
  Cop(Cstore (bigarray_word_kind elt_kind),
      [bigarray_indexing elt_kind layout b args; newval])

(* Simplification of some primitives into C calls *)

let default_prim name =
  { prim_name = name; prim_arity = 0 (*ignored*);
    prim_alloc = true; prim_native_name = ""; prim_native_float = false }

let simplif_primitive_32bits = function
    Pbintofint Pint64 -> Pccall (default_prim "int64_of_int")
  | Pintofbint Pint64 -> Pccall (default_prim "int64_to_int")
  | Pcvtbint(Pint32, Pint64) -> Pccall (default_prim "int64_of_int32")
  | Pcvtbint(Pint64, Pint32) -> Pccall (default_prim "int64_to_int32")
  | Pcvtbint(Pnativeint, Pint64) -> Pccall (default_prim "int64_of_nativeint")
  | Pcvtbint(Pint64, Pnativeint) -> Pccall (default_prim "int64_to_nativeint")
  | Pnegbint Pint64 -> Pccall (default_prim "int64_neg")
  | Paddbint Pint64 -> Pccall (default_prim "int64_add")
  | Psubbint Pint64 -> Pccall (default_prim "int64_sub")
  | Pmulbint Pint64 -> Pccall (default_prim "int64_mul")
  | Pdivbint Pint64 -> Pccall (default_prim "int64_div")
  | Pmodbint Pint64 -> Pccall (default_prim "int64_mod")
  | Pandbint Pint64 -> Pccall (default_prim "int64_and")
  | Porbint Pint64 ->  Pccall (default_prim "int64_or")
  | Pxorbint Pint64 -> Pccall (default_prim "int64_xor")
  | Plslbint Pint64 -> Pccall (default_prim "int64_shift_left")
  | Plsrbint Pint64 -> Pccall (default_prim "int64_shift_right_unsigned")
  | Pasrbint Pint64 -> Pccall (default_prim "int64_shift_right")
  | Pbintcomp(Pint64, Lambda.Ceq) -> Pccall (default_prim "equal")
  | Pbintcomp(Pint64, Lambda.Cneq) -> Pccall (default_prim "notequal")
  | Pbintcomp(Pint64, Lambda.Clt) -> Pccall (default_prim "lessthan")
  | Pbintcomp(Pint64, Lambda.Cgt) -> Pccall (default_prim "greaterthan")
  | Pbintcomp(Pint64, Lambda.Cle) -> Pccall (default_prim "lessequal")
  | Pbintcomp(Pint64, Lambda.Cge) -> Pccall (default_prim "greaterequal")
  | Pbigarrayref(n, Pbigarray_int64, layout) ->
      Pccall (default_prim ("bigarray_get_" ^ string_of_int n))
  | Pbigarrayset(n, Pbigarray_int64, layout) ->
      Pccall (default_prim ("bigarray_set_" ^ string_of_int n))
  | p -> p

let simplif_primitive p =
  match p with
    Pbigarrayref(n, Pbigarray_unknown, layout) ->
      Pccall (default_prim ("bigarray_get_" ^ string_of_int n))
  | Pbigarrayset(n, Pbigarray_unknown, layout) ->
      Pccall (default_prim ("bigarray_set_" ^ string_of_int n))
  | Pbigarrayref(n, kind, Pbigarray_unknown_layout) ->
      Pccall (default_prim ("bigarray_get_" ^ string_of_int n))
  | Pbigarrayset(n, kind, Pbigarray_unknown_layout) ->
      Pccall (default_prim ("bigarray_set_" ^ string_of_int n))
  | p ->
      if size_int = 8 then p else simplif_primitive_32bits p

(* Build switchers both for constants and blocks *)

(* constants first *)

let transl_isout h arg = tag_int (Cop(Ccmpa Clt, [h ; arg]))

exception Found of int

let make_switch_gen arg cases acts =
  let lcases = Array.length cases in
  let new_cases = Array.create lcases 0 in
  let store = Switch.mk_store (=) in
            
  for i = 0 to Array.length cases-1 do
    let act = cases.(i) in
    let new_act = store.Switch.act_store act in
    new_cases.(i) <- new_act
  done ;
  Cswitch
    (arg, new_cases,
     Array.map
       (fun n -> acts.(n))
       (store.Switch.act_get ()))


(* Then for blocks *)

module SArgBlocks =
struct
  type primitive = operation

  let eqint = Ccmpi Ceq
  let neint = Ccmpi Cne
  let leint = Ccmpi Cle
  let ltint = Ccmpi Clt
  let geint = Ccmpi Cge
  let gtint = Ccmpi Cgt

  type act = expression

  let default = Cexit (0,[])
  let make_prim p args = Cop (p,args)
  let make_offset arg n = add_const arg n
  let make_isout h arg =  Cop (Ccmpa Clt, [h ; arg])
  let make_isin h arg =  Cop (Ccmpa Cge, [h ; arg])
  let make_if cond ifso ifnot = Cifthenelse (cond, ifso, ifnot)
  let make_switch arg cases actions =
    make_switch_gen arg cases actions
  let bind arg body = bind "switcher" arg body

end

module SwitcherBlocks = Switch.Make(SArgBlocks)

(* Auxiliary functions for optimizing "let" of boxed numbers (floats and
   boxed integers *)

type unboxed_number_kind =
    No_unboxing
  | Boxed_float
  | Boxed_integer of boxed_integer

let is_unboxed_number = function
    Uconst(Const_base(Const_float f)) ->
      Boxed_float
  | Uprim(p, _) ->
      begin match simplif_primitive p with
          Pccall p -> if p.prim_native_float then Boxed_float else No_unboxing
        | Pfloatfield _ -> Boxed_float
        | Pfloatofint -> Boxed_float
        | Pnegfloat -> Boxed_float
        | Pabsfloat -> Boxed_float
        | Paddfloat -> Boxed_float
        | Psubfloat -> Boxed_float
        | Pmulfloat -> Boxed_float
        | Pdivfloat -> Boxed_float
        | Parrayrefu Pfloatarray -> Boxed_float
        | Parrayrefs Pfloatarray -> Boxed_float
        | Pbintofint bi -> Boxed_integer bi
        | Pcvtbint(src, dst) -> Boxed_integer dst
        | Pnegbint bi -> Boxed_integer bi
        | Paddbint bi -> Boxed_integer bi
        | Psubbint bi -> Boxed_integer bi
        | Pmulbint bi -> Boxed_integer bi
        | Pdivbint bi -> Boxed_integer bi
        | Pmodbint bi -> Boxed_integer bi
        | Pandbint bi -> Boxed_integer bi
        | Porbint bi -> Boxed_integer bi
        | Pxorbint bi -> Boxed_integer bi
        | Plslbint bi -> Boxed_integer bi
        | Plsrbint bi -> Boxed_integer bi
        | Pasrbint bi -> Boxed_integer bi
        | Pbigarrayref(_, (Pbigarray_float32 | Pbigarray_float64), _) ->
            Boxed_float
        | Pbigarrayref(_, Pbigarray_int32, _) -> Boxed_integer Pint32
        | Pbigarrayref(_, Pbigarray_int64, _) -> Boxed_integer Pint64
        | Pbigarrayref(_, Pbigarray_native_int, _) -> Boxed_integer Pnativeint
        | _ -> No_unboxing
      end
  | _ -> No_unboxing

let subst_boxed_number unbox_fn boxed_id unboxed_id exp =
  let need_boxed = ref false in
  let assigned = ref false in
  let rec subst = function
      Cvar id as e ->
        if Ident.same id boxed_id then need_boxed := true; e
    | Clet(id, arg, body) -> Clet(id, subst arg, subst body)
    | Cassign(id, arg) -> 
        if Ident.same id boxed_id then begin
          assigned := true;
          Cassign(unboxed_id, subst(unbox_fn arg))
        end else
          Cassign(id, subst arg)
    | Ctuple argv -> Ctuple(List.map subst argv)
    | Cop(Cload _, [Cvar id]) as e ->
        if Ident.same id boxed_id then Cvar unboxed_id else e
    | Cop(Cload _, [Cop(Cadda, [Cvar id; _])]) as e ->
        if Ident.same id boxed_id then Cvar unboxed_id else e
    | Cop(op, argv) -> Cop(op, List.map subst argv)
    | Csequence(e1, e2) -> Csequence(subst e1, subst e2)
    | Cifthenelse(e1, e2, e3) -> Cifthenelse(subst e1, subst e2, subst e3)
    | Cswitch(arg, index, cases) ->
        Cswitch(subst arg, index, Array.map subst cases)
    | Cloop e -> Cloop(subst e)
    | Ccatch(nfail, ids, e1, e2) -> Ccatch(nfail, ids, subst e1, subst e2)
    | Cexit (nfail, el) -> Cexit (nfail, List.map subst el)        
    | Ctrywith(e1, id, e2) -> Ctrywith(subst e1, id, subst e2)
    | e -> e in
  let res = subst exp in
  (res, !need_boxed, !assigned)  

(* Translate an expression *)

let functions = (Queue.create() : (string * Ident.t list * ulambda) Queue.t)

let rec transl = function
    Uvar id ->
      Cvar id
  | Uconst sc ->
      transl_constant sc
  | Uclosure(fundecls, []) ->
      let lbl = new_const_symbol() in
      constant_closures := (lbl, fundecls) :: !constant_closures;
      List.iter
        (fun (label, arity, params, body) ->
          Queue.add (label, params, body) functions)
        fundecls;
      Cconst_symbol lbl
  | Uclosure(fundecls, clos_vars) ->
      let block_size =
        fundecls_size fundecls + List.length clos_vars in
      let rec transl_fundecls pos = function
          [] ->
            List.map transl clos_vars
        | (label, arity, params, body) :: rem ->
            Queue.add (label, params, body) functions;
            let header =
              if pos = 0
              then alloc_closure_header block_size
              else alloc_infix_header pos in
            if arity = 1 then
              header ::
              Cconst_symbol label ::
              int_const 1 ::
              transl_fundecls (pos + 3) rem
            else
              header ::
              Cconst_symbol(curry_function arity) ::
              int_const arity ::
              Cconst_symbol label ::
              transl_fundecls (pos + 4) rem in
      Cop(Calloc, transl_fundecls 0 fundecls)
  | Uoffset(arg, offset) ->
      field_address (transl arg) offset
  | Udirect_apply(lbl, args) ->
      Cop(Capply typ_addr, Cconst_symbol lbl :: List.map transl args)
  | Ugeneric_apply(clos, [arg]) ->
      bind "fun" (transl clos) (fun clos ->
        Cop(Capply typ_addr, [get_field clos 0; transl arg; clos]))
  | Ugeneric_apply(clos, args) ->
      let arity = List.length args in
      let cargs = Cconst_symbol(apply_function arity) ::
        List.map transl (args @ [clos]) in
      Cop(Capply typ_addr, cargs)
  | Usend(met, obj, []) ->
      bind "obj" (transl obj) (fun obj ->
        bind "met" (lookup_label obj (transl met)) (fun clos ->
          Cop(Capply typ_addr, [get_field clos 0; obj; clos])))
  | Usend(met, obj, args) ->
      let arity = List.length args + 1 in
      bind "obj" (transl obj) (fun obj ->
        bind "met" (lookup_label obj (transl met)) (fun clos ->
          let cargs = Cconst_symbol(apply_function arity) ::
            obj :: (List.map transl args) @ [clos] in
          Cop(Capply typ_addr, cargs)))
  | Ulet(id, exp, body) ->
      begin match is_unboxed_number exp with
        No_unboxing ->
          Clet(id, transl exp, transl body)
      | Boxed_float ->
          transl_unbox_let box_float unbox_float transl_unbox_float
                           id exp body
      | Boxed_integer bi ->
          transl_unbox_let (box_int bi) (unbox_int bi) (transl_unbox_int bi)
                           id exp body
      end
  | Uletrec(bindings, body) ->
      transl_letrec bindings (transl body)

  (* Primitives *)
  | Uprim(prim, args) ->
      begin match (simplif_primitive prim, args) with
        (Pgetglobal id, []) ->
          Cconst_symbol(Ident.name id)
      | (Pmakeblock(tag, mut), []) ->
          transl_constant(Const_block(tag, []))
      | (Pmakeblock(tag, mut), args) ->
          Cop(Calloc, alloc_block_header tag (List.length args) ::
              List.map transl args)
      | (Pccall prim, args) ->
          if prim.prim_native_float then
            box_float
              (Cop(Cextcall(prim.prim_native_name, typ_float, false),
                   List.map transl_unbox_float args))
          else begin
            let name =
              if prim.prim_native_name <> ""
              then prim.prim_native_name
              else prim.prim_name in
            Cop(Cextcall(name, typ_addr, prim.prim_alloc),
                List.map transl args)
          end
      | (Pmakearray kind, []) ->
          transl_constant(Const_block(0, []))
      | (Pmakearray kind, args) ->
          begin match kind with
            Pgenarray ->
              Cop(Cextcall("make_array", typ_addr, true),
                  [Cop(Calloc, alloc_block_header 0 (List.length args) ::
                       List.map transl args)])
          | Paddrarray | Pintarray ->
              Cop(Calloc, alloc_block_header 0 (List.length args) ::
                  List.map transl args)
          | Pfloatarray ->
              Cop(Calloc, alloc_floatarray_header (List.length args) ::
                  List.map transl_unbox_float args)
          end
      | (Pbigarrayref(num_dims, elt_kind, layout), arg1 :: argl) ->
          let elt =
            bigarray_get elt_kind layout
              (transl arg1) (List.map transl argl) in
          begin match elt_kind with
            Pbigarray_float32 | Pbigarray_float64 -> box_float elt
          | Pbigarray_int32 -> box_int Pint32 elt
          | Pbigarray_int64 -> box_int Pint64 elt
          | Pbigarray_native_int -> box_int Pnativeint elt
          | Pbigarray_caml_int -> force_tag_int elt
          | _ -> tag_int elt
          end
      | (Pbigarrayset(num_dims, elt_kind, layout), arg1 :: argl) ->
          let (argidx, argnewval) = split_last argl in
          bigarray_set elt_kind layout
            (transl arg1)
            (List.map transl argidx)
            (match elt_kind with
              Pbigarray_float32 | Pbigarray_float64 ->
                transl_unbox_float argnewval
            | Pbigarray_int32 -> transl_unbox_int Pint32 argnewval
            | Pbigarray_int64 -> transl_unbox_int Pint64 argnewval
            | Pbigarray_native_int -> transl_unbox_int Pnativeint argnewval
            | _ -> untag_int (transl argnewval))
      | (p, [arg]) ->
          transl_prim_1 p arg
      | (p, [arg1; arg2]) ->
          transl_prim_2 p arg1 arg2
      | (p, [arg1; arg2; arg3]) ->
          transl_prim_3 p arg1 arg2 arg3
      | (_, _) ->
          fatal_error "Cmmgen.transl:prim"
      end

  (* Control structures *)
  | Uswitch(arg, s) ->
      (* As in the bytecode interpreter, only matching against constants
         can be checked *)
      if Array.length s.us_index_blocks = 0 then
        Cswitch
          (untag_int (transl arg),
           s.us_index_consts,
           Array.map transl s.us_actions_consts)
      else if Array.length s.us_index_consts = 0 then
        transl_switch (get_tag (transl arg))
          s.us_index_blocks s.us_actions_blocks
      else
        bind "switch" (transl arg) (fun arg ->
          Cifthenelse(
          Cop(Cand, [arg; Cconst_int 1]),
          transl_switch
            (untag_int arg) s.us_index_consts s.us_actions_consts,
          transl_switch
            (get_tag arg) s.us_index_blocks s.us_actions_blocks))
  | Ustaticfail (nfail, args) ->
      Cexit (nfail, List.map transl args)
  | Ucatch(nfail, [], body, handler) ->
      make_catch nfail (transl body) (transl handler)
  | Ucatch(nfail, ids, body, handler) ->
      Ccatch(nfail, ids, transl body, transl handler)
  | Utrywith(body, exn, handler) ->
      Ctrywith(transl body, exn, transl handler)
  | Uifthenelse(Uprim(Pnot, [arg]), ifso, ifnot) ->
      transl (Uifthenelse(arg, ifnot, ifso))
  | Uifthenelse(cond, ifso, Ustaticfail (nfail, [])) ->
      exit_if_false cond (transl ifso) nfail
  | Uifthenelse(cond, Ustaticfail (nfail, []), ifnot) ->
      exit_if_true cond nfail (transl ifnot)
  | Uifthenelse(Uprim(Psequand, _) as cond, ifso, ifnot) ->
      let raise_num = next_raise_count () in
      make_catch
        raise_num
        (exit_if_false cond (transl ifso) raise_num)
        (transl ifnot)
  | Uifthenelse(Uprim(Psequor, _) as cond, ifso, ifnot) ->
      let raise_num = next_raise_count () in      
      make_catch
        raise_num
        (exit_if_true cond raise_num (transl ifnot))
        (transl ifso)
  | Uifthenelse (Uifthenelse (cond, condso, condnot), ifso, ifnot) ->
      let num_true = next_raise_count () in
      make_catch
        num_true
        (make_catch2
           (fun shared_false ->
             Cifthenelse
               (test_bool (transl cond),
                exit_if_true condso num_true shared_false,
                exit_if_true condnot num_true shared_false))
           (transl ifnot))
        (transl ifso)
  | Uifthenelse(cond, ifso, ifnot) ->
      Cifthenelse(test_bool(transl cond), transl ifso, transl ifnot)
  | Usequence(exp1, exp2) ->
      Csequence(remove_unit(transl exp1), transl exp2)
  | Uwhile(cond, body) ->
      let raise_num = next_raise_count () in
      return_unit
        (Ccatch
           (raise_num, [],
            Cloop(exit_if_false cond (remove_unit(transl body)) raise_num),
            Ctuple []))
  | Ufor(id, low, high, dir, body) ->
      let tst = match dir with Upto -> Cgt   | Downto -> Clt in
      let inc = match dir with Upto -> Caddi | Downto -> Csubi in
      let raise_num = next_raise_count () in
      return_unit
        (Clet
           (id, transl low,
            bind_nonvar "bound" (transl high) (fun high ->
              Ccatch
                (raise_num, [],
                 Cifthenelse
                   (Cop(Ccmpi tst, [Cvar id; high]), Cexit (raise_num, []),
                    Cloop
                      (Csequence
                         (remove_unit(transl body),
                          Csequence
                            (Cassign(id, Cop(inc, [Cvar id; Cconst_int 2])),
                             Cifthenelse
                               (Cop(Ccmpi tst, [Cvar id; high]),
                                Cexit (raise_num,[]), Ctuple []))))),
                 Ctuple []))))
  | Uassign(id, exp) ->
      return_unit(Cassign(id, transl exp))

and transl_prim_1 p arg =
  match p with
  (* Generic operations *)
    Pidentity ->
      transl arg
  | Pignore ->
      return_unit(remove_unit (transl arg))
  (* Heap operations *)
  | Pfield n ->
      get_field (transl arg) n
  | Pfloatfield n ->
      let ptr = transl arg in
      box_float(
        Cop(Cload Double_u,
            [if n = 0 then ptr
                       else Cop(Cadda, [ptr; Cconst_int(n * size_float)])]))
  (* Exceptions *)
  | Praise ->
      Cop(Craise, [transl arg])
  (* Integer operations *)
  | Pnegint ->
      Cop(Csubi, [Cconst_int 2; transl arg])
  | Poffsetint n ->
      if no_overflow_lsl n then
        add_const (transl arg) (n lsl 1)
      else
        transl_prim_2 Paddint arg (Uconst (Const_base(Const_int n)))
  | Poffsetref n ->
      return_unit
        (bind "ref" (transl arg) (fun arg ->
          Cop(Cstore Word,
              [arg; add_const (Cop(Cload Word, [arg])) (n lsl 1)])))
  (* Floating-point operations *)
  | Pfloatofint ->
      box_float(Cop(Cfloatofint, [untag_int(transl arg)]))
  | Pintoffloat ->
     tag_int(Cop(Cintoffloat, [transl_unbox_float arg]))
  | Pnegfloat ->
      box_float(Cop(Cnegf, [transl_unbox_float arg]))
  | Pabsfloat ->
      box_float(Cop(Cabsf, [transl_unbox_float arg]))
  (* String operations *)
  | Pstringlength ->
      tag_int(string_length (transl arg))
  (* Array operations *)
  | Parraylength kind ->
      begin match kind with
        Pgenarray ->
          let len =
            if wordsize_shift = numfloat_shift then
              Cop(Clsr, [header(transl arg); Cconst_int wordsize_shift])
            else
              bind "header" (header(transl arg)) (fun hdr ->
                Cifthenelse(is_addr_array_hdr hdr,
                            Cop(Clsr, [hdr; Cconst_int wordsize_shift]),
                            Cop(Clsr, [hdr; Cconst_int numfloat_shift]))) in
          Cop(Cor, [len; Cconst_int 1])
      | Paddrarray | Pintarray ->
          Cop(Cor, [addr_array_length(header(transl arg)); Cconst_int 1])
      | Pfloatarray ->
          Cop(Cor, [float_array_length(header(transl arg)); Cconst_int 1])
      end
  (* Boolean operations *)
  | Pnot ->
      Cop(Csubi, [Cconst_int 4; transl arg]) (* 1 -> 3, 3 -> 1 *)
  (* Test integer/block *)
  | Pisint ->
      tag_int(Cop(Cand, [transl arg; Cconst_int 1]))
  (* Boxed integers *)
  | Pbintofint bi ->
      box_int bi (untag_int (transl arg))
  | Pintofbint bi ->
      force_tag_int (transl_unbox_int bi arg)
  | Pcvtbint(bi1, bi2) ->
      box_int bi2 (transl_unbox_int bi1 arg)
  | Pnegbint bi ->
      box_int bi (Cop(Csubi, [Cconst_int 0; transl_unbox_int bi arg]))
  | _ ->
      fatal_error "Cmmgen.transl_prim_1"

and transl_prim_2 p arg1 arg2 =
  match p with
  (* Heap operations *)
    Psetfield(n, ptr) ->
      if ptr then
        return_unit(Cop(Cextcall("modify", typ_void, false),
                        [field_address (transl arg1) n; transl arg2]))
      else
        return_unit(set_field (transl arg1) n (transl arg2))
  | Psetfloatfield n ->
      let ptr = transl arg1 in
      return_unit(
        Cop(Cstore Double_u,
            [if n = 0 then ptr
                       else Cop(Cadda, [ptr; Cconst_int(n * size_float)]);
                   transl_unbox_float arg2]))

  (* Boolean operations *)
  | Psequand ->
      Cifthenelse(test_bool(transl arg1), transl arg2, Cconst_int 1)
  | Psequor ->
      Cifthenelse(test_bool(transl arg1), Cconst_int 3, transl arg2)

  (* Integer operations *)
  | Paddint ->
      decr_int(add_int (transl arg1) (transl arg2))
  | Psubint ->
      incr_int(sub_int (transl arg1) (transl arg2))
  | Pmulint ->
      incr_int(Cop(Cmuli, [decr_int(transl arg1); untag_int(transl arg2)]))
  | Pdivint ->
      tag_int(Cop(Cdivi, [untag_int(transl arg1); untag_int(transl arg2)]))
  | Pmodint ->
      tag_int(Cop(Cmodi, [untag_int(transl arg1); untag_int(transl arg2)]))
  | Pandint ->
      Cop(Cand, [transl arg1; transl arg2])
  | Porint ->
      Cop(Cor, [transl arg1; transl arg2])
  | Pxorint ->
      Cop(Cor, [Cop(Cxor, [ignore_low_bit_int(transl arg1);
                           ignore_low_bit_int(transl arg2)]);
                Cconst_int 1])
  | Plslint ->
      incr_int(lsl_int (decr_int(transl arg1)) (untag_int(transl arg2)))
  | Plsrint ->
      Cop(Cor, [Cop(Clsr, [transl arg1; untag_int(transl arg2)]);
                Cconst_int 1])
  | Pasrint ->
      Cop(Cor, [Cop(Casr, [transl arg1; untag_int(transl arg2)]);
                Cconst_int 1])
  | Pintcomp cmp ->
      tag_int(Cop(Ccmpi(transl_comparison cmp), [transl arg1; transl arg2]))
  | Pisout ->
      transl_isout (transl arg1) (transl arg2)        
  (* Float operations *)
  | Paddfloat ->
      box_float(Cop(Caddf,
                    [transl_unbox_float arg1; transl_unbox_float arg2]))
  | Psubfloat ->
      box_float(Cop(Csubf,
                    [transl_unbox_float arg1; transl_unbox_float arg2]))
  | Pmulfloat ->
      box_float(Cop(Cmulf,
                    [transl_unbox_float arg1; transl_unbox_float arg2]))
  | Pdivfloat ->
      box_float(Cop(Cdivf,
                    [transl_unbox_float arg1; transl_unbox_float arg2]))
  | Pfloatcomp cmp ->
      tag_int(Cop(Ccmpf(transl_comparison cmp),
                  [transl_unbox_float arg1; transl_unbox_float arg2]))

  (* String operations *)
  | Pstringrefu ->
      tag_int(Cop(Cload Byte_unsigned,
                  [add_int (transl arg1) (untag_int(transl arg2))]))
  | Pstringrefs ->
      tag_int
        (bind "str" (transl arg1) (fun str ->
          bind "index" (untag_int (transl arg2)) (fun idx ->
            Csequence(
              Cop(Ccheckbound, [string_length str; idx]),
              Cop(Cload Byte_unsigned, [add_int str idx])))))

  (* Array operations *)
  | Parrayrefu kind ->
      begin match kind with
        Pgenarray ->
          bind "arr" (transl arg1) (fun arr ->
            bind "index" (transl arg2) (fun idx ->
              Cifthenelse(is_addr_array_ptr arr,
                          addr_array_ref arr idx,
                          float_array_ref arr idx)))
      | Paddrarray | Pintarray ->
          addr_array_ref (transl arg1) (transl arg2)
      | Pfloatarray ->
          float_array_ref (transl arg1) (transl arg2)
      end
  | Parrayrefs kind ->
      begin match kind with
        Pgenarray ->
          bind "index" (transl arg2) (fun idx ->
            bind "arr" (transl arg1) (fun arr ->
              bind "header" (header arr) (fun hdr ->
                Cifthenelse(is_addr_array_hdr hdr,
                  Csequence(Cop(Ccheckbound, [addr_array_length hdr; idx]),
                            addr_array_ref arr idx),
                  Csequence(Cop(Ccheckbound, [float_array_length hdr; idx]),
                            float_array_ref arr idx)))))
      | Paddrarray | Pintarray ->
          bind "index" (transl arg2) (fun idx ->
            bind "arr" (transl arg1) (fun arr ->
              Csequence(Cop(Ccheckbound, [addr_array_length(header arr); idx]),
                        addr_array_ref arr idx)))
      | Pfloatarray ->
          box_float(
            bind "index" (transl arg2) (fun idx ->
              bind "arr" (transl arg1) (fun arr ->
                Csequence(Cop(Ccheckbound, 
                              [float_array_length(header arr); idx]),
                          unboxed_float_array_ref arr idx))))
      end

  (* Operations on bitvects *)
  | Pbittest ->
      bind "index" (untag_int(transl arg2)) (fun idx ->
        tag_int(
          Cop(Cand, [Cop(Clsr, [Cop(Cload Byte_unsigned,
                                    [add_int (transl arg1)
                                      (Cop(Clsr, [idx; Cconst_int 3]))]);
                                Cop(Cand, [idx; Cconst_int 7])]);
                     Cconst_int 1])))

  (* Boxed integers *)
  | Paddbint bi ->
      box_int bi (Cop(Caddi,
                      [transl_unbox_int bi arg1; transl_unbox_int bi arg2]))
  | Psubbint bi ->
      box_int bi (Cop(Csubi,
                      [transl_unbox_int bi arg1; transl_unbox_int bi arg2]))
  | Pmulbint bi ->
      box_int bi (Cop(Cmuli, 
                      [transl_unbox_int bi arg1; transl_unbox_int bi arg2]))
  | Pdivbint bi ->
      box_int bi (Cop(Cdivi,
                      [transl_unbox_int bi arg1; transl_unbox_int bi arg2]))
  | Pmodbint bi ->
      box_int bi (Cop(Cmodi,
                     [transl_unbox_int bi arg1; transl_unbox_int bi arg2]))
  | Pandbint bi ->
      box_int bi (Cop(Cand,
                     [transl_unbox_int bi arg1; transl_unbox_int bi arg2]))
  | Porbint bi ->
      box_int bi (Cop(Cor,
                     [transl_unbox_int bi arg1; transl_unbox_int bi arg2]))
  | Pxorbint bi ->
      box_int bi (Cop(Cxor,
                     [transl_unbox_int bi arg1; transl_unbox_int bi arg2]))
  | Plslbint bi ->
      box_int bi (Cop(Clsl,
                     [transl_unbox_int bi arg1; untag_int(transl arg2)]))
  | Plsrbint bi ->
      box_int bi (Cop(Clsr,
                     [unbox_unsigned_int bi (transl arg1);
                      untag_int(transl arg2)]))
  | Pasrbint bi ->
      box_int bi (Cop(Casr,
                     [transl_unbox_int bi arg1; untag_int(transl arg2)]))
  | Pbintcomp(bi, cmp) ->
      tag_int (Cop(Ccmpi(transl_comparison cmp),
                     [transl_unbox_int bi arg1; transl_unbox_int bi arg2]))
  | _ ->
      fatal_error "Cmmgen.transl_prim_2"

and transl_prim_3 p arg1 arg2 arg3 =
  match p with
  (* String operations *)
    Pstringsetu ->
      return_unit(Cop(Cstore Byte_unsigned,
                      [add_int (transl arg1) (untag_int(transl arg2));
                        untag_int(transl arg3)]))
  | Pstringsets ->
      return_unit
        (bind "str" (transl arg1) (fun str ->
          bind "index" (untag_int (transl arg2)) (fun idx ->
            Csequence(
              Cop(Ccheckbound, [string_length str; idx]),
              Cop(Cstore Byte_unsigned,
                  [add_int str idx; untag_int(transl arg3)])))))

  (* Array operations *)
  | Parraysetu kind ->
      return_unit(begin match kind with
        Pgenarray ->
          bind "newval" (transl arg3) (fun newval ->
            bind "index" (transl arg2) (fun index ->
              bind "arr" (transl arg1) (fun arr ->
                Cifthenelse(is_addr_array_ptr arr,
                            addr_array_set arr index newval,
                            float_array_set arr index (unbox_float newval)))))
      | Paddrarray ->
          addr_array_set (transl arg1) (transl arg2) (transl arg3)
      | Pintarray ->
          int_array_set (transl arg1) (transl arg2) (transl arg3)
      | Pfloatarray ->
          float_array_set (transl arg1) (transl arg2) (transl_unbox_float arg3)
      end)
  | Parraysets kind ->
      return_unit(begin match kind with
        Pgenarray ->
          bind "newval" (transl arg3) (fun newval ->
            bind "index" (transl arg2) (fun idx ->
              bind "arr" (transl arg1) (fun arr ->
                bind "header" (header arr) (fun hdr ->
                  Cifthenelse(is_addr_array_hdr hdr,
                    Csequence(Cop(Ccheckbound, [addr_array_length hdr; idx]),
                              addr_array_set arr idx newval),
                    Csequence(Cop(Ccheckbound, [float_array_length hdr; idx]),
                              float_array_set arr idx
                                              (unbox_float newval)))))))
      | Paddrarray ->
          bind "index" (transl arg2) (fun idx ->
            bind "arr" (transl arg1) (fun arr ->
              Csequence(Cop(Ccheckbound, [addr_array_length(header arr); idx]),
                        addr_array_set arr idx (transl arg3))))
      | Pintarray ->
          bind "index" (transl arg2) (fun idx ->
            bind "arr" (transl arg1) (fun arr ->
              Csequence(Cop(Ccheckbound, [addr_array_length(header arr); idx]),
                        int_array_set arr idx (transl arg3))))
      | Pfloatarray ->
          bind "index" (transl arg2) (fun idx ->
            bind "arr" (transl arg1) (fun arr ->
              Csequence(Cop(Ccheckbound, [float_array_length(header arr);idx]),
                        float_array_set arr idx (transl_unbox_float arg3))))
      end)
  | _ ->
    fatal_error "Cmmgen.transl_prim_3"

and transl_unbox_float = function
    Uconst(Const_base(Const_float f)) -> Cconst_float f
  | exp -> unbox_float(transl exp)

and transl_unbox_int bi = function
    Uprim(Pbintofint bi', [Uconst(Const_base(Const_int i))]) when bi = bi' ->
      Cconst_int i
  | exp -> unbox_int bi (transl exp)

and transl_unbox_let box_fn unbox_fn transl_unbox_fn id exp body =
  let unboxed_id = Ident.create (Ident.name id) in
  let (tr_body, need_boxed, is_assigned) =
    subst_boxed_number unbox_fn id unboxed_id (transl body) in
  if need_boxed && is_assigned then
    Clet(id, transl exp, transl body)
  else
    Clet(unboxed_id, transl_unbox_fn exp,
         if need_boxed
         then Clet(id, box_fn(Cvar unboxed_id), tr_body)
         else tr_body)

and make_catch ncatch body handler = match body with
| Cexit (nexit,[]) when nexit=ncatch -> handler
| _ ->  Ccatch (ncatch, [], body, handler) 

and make_catch2 mk_body handler = match handler with
| Cexit (_,[])|Ctuple []|Cconst_int _|Cconst_pointer _ ->
    mk_body handler
| _ ->
    let nfail = next_raise_count () in
    make_catch
      nfail
      (mk_body (Cexit (nfail,[])))
      handler
  
and exit_if_true cond nfail otherwise =
  match cond with
  | Uconst (Const_pointer 0) -> otherwise
  | Uconst (Const_pointer 1) -> Cexit (nfail,[])
  | Uprim(Psequor, [arg1; arg2]) ->
      exit_if_true arg1 nfail (exit_if_true arg2 nfail otherwise)
  | Uprim(Psequand, _) ->
      begin match otherwise with
      | Cexit (raise_num,[]) ->
          exit_if_false cond (Cexit (nfail,[])) raise_num 
      | _ ->
          let raise_num = next_raise_count () in
          make_catch
            raise_num
            (exit_if_false cond (Cexit (nfail,[])) raise_num)
            otherwise
      end   
  | Uprim(Pnot, [arg]) ->
      exit_if_false arg otherwise nfail
  | Uifthenelse (cond, ifso, ifnot) ->
      make_catch2
        (fun shared ->
          Cifthenelse
            (test_bool (transl cond),
             exit_if_true ifso nfail shared,
             exit_if_true ifnot nfail shared))
        otherwise
  | _ ->
      Cifthenelse(test_bool(transl cond), Cexit (nfail, []), otherwise)

and exit_if_false cond otherwise nfail =
  match cond with
  | Uconst (Const_pointer 0) -> Cexit (nfail,[])
  | Uconst (Const_pointer 1) -> otherwise
  | Uprim(Psequand, [arg1; arg2]) ->
      exit_if_false arg1 (exit_if_false arg2 otherwise nfail) nfail
  | Uprim(Psequor, _ ) ->
      begin match otherwise with
      | Cexit (raise_num,[]) ->
          exit_if_true cond raise_num (Cexit (nfail,[]))
      | _ ->
          let raise_num = next_raise_count () in
          make_catch
            raise_num
            (exit_if_true cond raise_num (Cexit (nfail,[])))
            otherwise
      end
  | Uprim(Pnot, [arg]) ->
      exit_if_true arg nfail otherwise
  | Uifthenelse (cond, ifso, ifnot) ->
      make_catch2
        (fun shared ->
          Cifthenelse
            (test_bool (transl cond),
             exit_if_false ifso shared nfail,
             exit_if_false ifnot shared nfail))
        otherwise
  | _ ->
      Cifthenelse(test_bool(transl cond), otherwise, Cexit (nfail, []))

and transl_switch arg index cases = match Array.length cases with
| 0 -> fatal_error "Cmmgen.transl_switch"
| 1 -> transl cases.(0)
| _ ->
    let n_index = Array.length index in
    let actions = Array.map transl cases in
      
    let inters = ref []
    and this_high = ref (n_index-1)
    and this_low = ref (n_index-1)
    and this_act = ref index.(n_index-1) in
    for i = n_index-2 downto 0 do
      let act = index.(i) in
      if act = !this_act then
        decr this_low
      else begin
        inters := (!this_low, !this_high, !this_act) :: !inters ;
        this_high := i ;
        this_low := i ;
        this_act := act
      end
    done ;
    inters := (0, !this_high, !this_act) :: !inters ;
    bind "switcher" arg
      (fun a ->
        SwitcherBlocks.zyva
          (0,n_index-1)
          (fun i -> Cconst_int i)
          a
          (Array.of_list !inters) actions)
        
and transl_letrec bindings cont =
  let rec init_blocks = function
      [] -> fill_blocks bindings
    | (id, exp) :: rem ->
        Clet(id, Cop(Cextcall("alloc_dummy", typ_addr, true),
                     [int_const(expr_size exp)]),
             init_blocks rem)
  and fill_blocks = function
      [] -> cont
    | (id, exp) :: rem ->
        Csequence(Cop(Cextcall("update_dummy", typ_void, false),
                      [Cvar id; transl exp]),
                  fill_blocks rem)
  in init_blocks bindings

(* Translate a function definition *)

let transl_function lbl params body =
  Cfunction {fun_name = lbl;
             fun_args = List.map (fun id -> (id, typ_addr)) params;
             fun_body = transl body;
             fun_fast = !Clflags.optimize_for_speed}

(* Translate all function definitions *)

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

let rec transl_all_functions already_translated cont =
  try
    let (lbl, params, body) = Queue.take functions in
    if StringSet.mem lbl already_translated then
      transl_all_functions already_translated cont
    else begin
      transl_all_functions (StringSet.add lbl already_translated)
                           (transl_function lbl params body :: cont)
    end
  with Queue.Empty ->
    cont

(* Emit structured constants *)

let rec emit_constant symb cst cont =
  match cst with
    Const_base(Const_float s) ->
      Cint(float_header) :: Cdefine_symbol symb :: Cdouble s :: cont
  | Const_base(Const_string s) ->
      Cint(string_header (String.length s)) ::
      Cdefine_symbol symb ::
      emit_string_constant s cont
  | Const_block(tag, fields) ->
      let (emit_fields, cont1) = emit_constant_fields fields cont in
      Cint(block_header tag (List.length fields)) ::
      Cdefine_symbol symb ::
      emit_fields @ cont1
  | Const_float_array(fields) ->
      Cint(floatarray_header (List.length fields)) ::
      Cdefine_symbol symb ::
      Misc.map_end (fun f -> Cdouble f) fields cont
  | _ -> fatal_error "gencmm.emit_constant"

and emit_constant_fields fields cont =
  match fields with
    [] -> ([], cont)
  | f1 :: fl ->
      let (data1, cont1) = emit_constant_field f1 cont in
      let (datal, contl) = emit_constant_fields fl cont1 in
      (data1 :: datal, contl)

and emit_constant_field field cont =
  match field with
    Const_base(Const_int n) ->
      (Cint(Nativeint.add (Nativeint.shift_left (Nativeint.of_int n) 1) 
                          Nativeint.one),
       cont)
  | Const_base(Const_char c) ->
      (Cint(Nativeint.of_int(((Char.code c) lsl 1) + 1)), cont)
  | Const_base(Const_float s) ->
      let lbl = new_const_label() in
      (Clabel_address lbl,
       Cint(float_header) :: Cdefine_label lbl :: Cdouble s :: cont)
  | Const_base(Const_string s) ->
      let lbl = new_const_label() in
      (Clabel_address lbl,
       Cint(string_header (String.length s)) :: Cdefine_label lbl :: 
       emit_string_constant s cont)
  | Const_pointer n ->
      (Cint(Nativeint.of_int((n lsl 1) + 1)), cont)
  | Const_block(tag, fields) ->
      let lbl = new_const_label() in
      let (emit_fields, cont1) = emit_constant_fields fields cont in
      (Clabel_address lbl,
       Cint(block_header tag (List.length fields)) :: Cdefine_label lbl ::
       emit_fields @ cont1)
  | Const_float_array(fields) ->
      let lbl = new_const_label() in
      (Clabel_address lbl,
       Cint(floatarray_header (List.length fields)) :: Cdefine_label lbl ::
       Misc.map_end (fun f -> Cdouble f) fields cont)

and emit_string_constant s cont =
  let n = size_int - 1 - (String.length s) mod size_int in
  Cstring s :: Cskip n :: Cint8 n :: cont

(* Emit boxed integer constants *)

let emit_boxedint_constant lbl bi n =
  Cint boxedint_header ::
  Cdefine_symbol lbl ::
  Csymbol_address(operations_boxed_int bi) ::
  (if bi = Pint32 && size_int = 8
   then [Cint32 n; Cint32 Nativeint.zero]
   else [Cint n])

(* Emit constant closures *)

let emit_constant_closure symb fundecls cont =
  match fundecls with
    [] -> assert false
  | (label, arity, params, body) :: remainder ->
      let rec emit_others pos = function
        [] -> cont
      | (label, arity, params, body) :: rem ->
          if arity = 1 then
            Cint(infix_header pos) ::
            Csymbol_address label ::
            Cint(Nativeint.of_int 3) ::
            emit_others (pos + 3) rem
          else
            Cint(infix_header pos) ::
            Csymbol_address(curry_function arity) ::
            Cint(Nativeint.of_int (arity lsl 1 + 1)) ::
            Csymbol_address label ::
            emit_others (pos + 4) rem in
      Cint(closure_header (fundecls_size fundecls)) ::
      Cdefine_symbol symb ::
      if arity = 1 then
        Csymbol_address label ::
        Cint(Nativeint.of_int 3) ::
        emit_others 3 remainder
      else
        Csymbol_address(curry_function arity) ::
        Cint(Nativeint.of_int (arity lsl 1 + 1)) ::
        Csymbol_address label ::
        emit_others 4 remainder

(* Emit all structured constants *)

let emit_all_constants cont =
  let c = ref cont in
  List.iter
    (fun (lbl, cst) -> c := Cdata(emit_constant lbl cst []) :: !c)
    !structured_constants;
  structured_constants := [];
  List.iter
    (fun (symb, bi, n) ->
        c := Cdata(emit_boxedint_constant symb bi n) :: !c)
    !constant_boxed_ints;
  constant_boxed_ints := [];
  List.iter
    (fun (symb, fundecls) ->
        c := Cdata(emit_constant_closure symb fundecls []) :: !c)
    !constant_closures;
  constant_closures := [];
  !c

(* Translate a compilation unit *)

let compunit size ulam =
  let glob = Compilenv.current_unit_name () in
  let init_code = transl ulam in
  let c1 = [Cfunction {fun_name = glob ^ "_entry"; fun_args = [];
                       fun_body = init_code; fun_fast = false}] in
  let c2 = transl_all_functions StringSet.empty c1 in
  let c3 = emit_all_constants c2 in
  Cdata [Cint(block_header 0 size);
         Cdefine_symbol glob;
         Cskip(size * size_addr)] :: c3

(* Generate an application function:
     (defun caml_applyN (a1 ... aN clos)
       (if (= clos.arity N)
         (app clos.direct a1 ... aN clos)
         (let (clos1 (app clos.code a1 clos)
               clos2 (app clos1.code a2 clos)
               ...
               closN-1 (app closN-2.code aN-1 closN-2))
           (app closN-1.code aN closN-1))))
*)

let apply_function arity =
  let arg = Array.create arity (Ident.create "arg") in
  for i = 1 to arity - 1 do arg.(i) <- Ident.create "arg" done;
  let clos = Ident.create "clos" in
  let rec app_fun clos n =
    if n = arity-1 then
      Cop(Capply typ_addr,
          [get_field (Cvar clos) 0; Cvar arg.(n); Cvar clos])
    else begin
      let newclos = Ident.create "clos" in
      Clet(newclos,
           Cop(Capply typ_addr,
               [get_field (Cvar clos) 0; Cvar arg.(n); Cvar clos]),
           app_fun newclos (n+1))
    end in
  let all_args = Array.to_list arg @ [clos] in
  let body =
    Cifthenelse(
      Cop(Ccmpi Ceq, [get_field (Cvar clos) 1; int_const arity]),
      Cop(Capply typ_addr,
          get_field (Cvar clos) 2 :: List.map (fun s -> Cvar s) all_args),
      app_fun clos 0) in
  Cfunction
   {fun_name = "caml_apply" ^ string_of_int arity;
    fun_args = List.map (fun id -> (id, typ_addr)) all_args;
    fun_body = body;
    fun_fast = true}

(* Generate tuplifying functions:
      (defun caml_tuplifyN (arg clos)
        (app clos.direct #0(arg) ... #N-1(arg) clos)) *)

let tuplify_function arity =
  let arg = Ident.create "arg" in
  let clos = Ident.create "clos" in
  let rec access_components i =
    if i >= arity
    then []
    else get_field (Cvar arg) i :: access_components(i+1) in
  Cfunction
   {fun_name = "caml_tuplify" ^ string_of_int arity;
    fun_args = [arg, typ_addr; clos, typ_addr];
    fun_body =
      Cop(Capply typ_addr,
          get_field (Cvar clos) 2 :: access_components 0 @ [Cvar clos]);
    fun_fast = true}

(* Generate currying functions:
      (defun caml_curryN (arg clos)
         (alloc HDR caml_curryN_1 arg clos))
      (defun caml_curryN_1 (arg clos)
         (alloc HDR caml_curryN_2 arg clos))
      ...
      (defun caml_curryN_N-1 (arg clos)
         (let (closN-2 clos.cdr
               closN-3 closN-2.cdr
               ...
               clos1 clos2.cdr
               clos clos1.cdr)
           (app clos.direct
                clos1.car clos2.car ... closN-2.car clos.car arg clos))) *)

let final_curry_function arity =
  let last_arg = Ident.create "arg" in
  let last_clos = Ident.create "clos" in
  let rec curry_fun args clos n =
    if n = 0 then
      Cop(Capply typ_addr,
          get_field (Cvar clos) 2 ::
          args @ [Cvar last_arg; Cvar clos])
    else begin
      let newclos = Ident.create "clos" in
      Clet(newclos,
           get_field (Cvar clos) 3,
           curry_fun (get_field (Cvar clos) 2 :: args) newclos (n-1))
    end in
  Cfunction
   {fun_name = "caml_curry" ^ string_of_int arity ^
               "_" ^ string_of_int (arity-1);
    fun_args = [last_arg, typ_addr; last_clos, typ_addr];
    fun_body = curry_fun [] last_clos (arity-1);
    fun_fast = true}

let rec intermediate_curry_functions arity num =
  if num = arity - 1 then
    [final_curry_function arity]
  else begin
    let name1 = "caml_curry" ^ string_of_int arity in
    let name2 = if num = 0 then name1 else name1 ^ "_" ^ string_of_int num in
    let arg = Ident.create "arg" and clos = Ident.create "clos" in
    Cfunction
     {fun_name = name2;
      fun_args = [arg, typ_addr; clos, typ_addr];
      fun_body = Cop(Calloc,
                     [alloc_closure_header 4; 
                      Cconst_symbol(name1 ^ "_" ^ string_of_int (num+1));
                      int_const 1; Cvar arg; Cvar clos]);
      fun_fast = true}
    :: intermediate_curry_functions arity (num+1)
  end
    
let curry_function arity =
  if arity >= 0
  then intermediate_curry_functions arity 0
  else [tuplify_function (-arity)]

(* Generate the entry point *)

let entry_point namelist =
  let incr_global_inited =
    Cop(Cstore Word,
        [Cconst_symbol "caml_globals_inited";
         Cop(Caddi, [Cop(Cload Word, [Cconst_symbol "caml_globals_inited"]);
                     Cconst_int 1])]) in
  let body =
    List.fold_right
      (fun name next ->
        Csequence(Cop(Capply typ_void, [Cconst_symbol(name ^ "_entry")]),
                  Csequence(incr_global_inited, next)))
      namelist (Cconst_int 1) in
  Cfunction {fun_name = "caml_program";
             fun_args = [];
             fun_body = body;
             fun_fast = false}

(* Generate the table of globals *)

let cint_zero = Cint(Nativeint.zero)

let global_table namelist =
  Cdata(Cdefine_symbol "caml_globals" ::
        List.map (fun name -> Csymbol_address name) namelist @
        [cint_zero])

let globals_map namelist =
  Cdata(emit_constant "globals_map"
          (Const_base (Const_string (Marshal.to_string namelist []))) [])

(* Generate the master table of frame descriptors *)

let frame_table namelist =
  Cdata(Cdefine_symbol "caml_frametable" ::
        List.map (fun name -> Csymbol_address(name ^ "_frametable")) namelist @
        [cint_zero])

(* Generate the table of module data and code segments *)

let segment_table namelist symbol begname endname =
  Cdata(Cdefine_symbol symbol ::
        List.fold_right
          (fun name lst ->
            Csymbol_address(name ^ begname) ::
            Csymbol_address(name ^ endname) :: lst)
          namelist
          [cint_zero])

let data_segment_table namelist =
  segment_table namelist "caml_data_segments" "_data_begin" "_data_end"

let code_segment_table namelist =
  segment_table namelist "caml_code_segments" "_code_begin" "_code_end"

(* Initialize a predefined exception *)

let predef_exception name =
  Cdata(emit_constant name (Const_block(0,[Const_base(Const_string name)])) [])