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(* *********************************************************************)
(* *)
(* The Compcert verified compiler *)
(* *)
(* Xavier Leroy, INRIA Paris-Rocquencourt *)
(* *)
(* Copyright Institut National de Recherche en Informatique et en *)
(* Automatique. All rights reserved. This file is distributed *)
(* under the terms of the INRIA Non-Commercial License Agreement. *)
(* *)
(* *********************************************************************)
open Switch
open CminorSel
let more_likely (c: condexpr) (ifso: stmt) (ifnot: stmt) = false
module IntOrd =
struct
type t = Integers.int
let compare x y =
if Integers.Int.eq x y then 0 else
if Integers.Int.ltu x y then -1 else 1
end
module IntSet = Set.Make(IntOrd)
let normalize_table tbl =
let rec norm seen = function
| CList.Coq_nil -> []
| CList.Coq_cons(Datatypes.Coq_pair(key, act), rem) ->
if IntSet.mem key seen
then norm seen rem
else (key, act) :: norm (IntSet.add key seen) rem
in norm IntSet.empty tbl
let compile_switch default table =
let sw = Array.of_list (normalize_table table) in
Array.stable_sort (fun (n1, _) (n2, _) -> IntOrd.compare n1 n2) sw;
let rec build lo hi =
match hi - lo with
| 0 ->
CTaction default
| 1 ->
CTifeq(fst sw.(lo), snd sw.(lo), CTaction default)
| 2 ->
CTifeq(fst sw.(lo), snd sw.(lo),
CTifeq(fst sw.(lo+1), snd sw.(lo+1),
CTaction default))
| 3 ->
CTifeq(fst sw.(lo), snd sw.(lo),
CTifeq(fst sw.(lo+1), snd sw.(lo+1),
CTifeq(fst sw.(lo+2), snd sw.(lo+2),
CTaction default)))
| _ ->
let mid = (lo + hi) / 2 in
CTiflt(fst sw.(mid), build lo mid, build mid hi)
in build 0 (Array.length sw)
|
