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|
(**************************************************************************)
(* Sail *)
(* *)
(* Copyright (c) 2013-2017 *)
(* Kathyrn Gray *)
(* Shaked Flur *)
(* Stephen Kell *)
(* Gabriel Kerneis *)
(* Robert Norton-Wright *)
(* Christopher Pulte *)
(* Peter Sewell *)
(* Alasdair Armstrong *)
(* Brian Campbell *)
(* Thomas Bauereiss *)
(* Anthony Fox *)
(* Jon French *)
(* Dominic Mulligan *)
(* Stephen Kell *)
(* Mark Wassell *)
(* *)
(* All rights reserved. *)
(* *)
(* This software was developed by the University of Cambridge Computer *)
(* Laboratory as part of the Rigorous Engineering of Mainstream Systems *)
(* (REMS) project, funded by EPSRC grant EP/K008528/1. *)
(* *)
(* Redistribution and use in source and binary forms, with or without *)
(* modification, are permitted provided that the following conditions *)
(* are met: *)
(* 1. Redistributions of source code must retain the above copyright *)
(* notice, this list of conditions and the following disclaimer. *)
(* 2. Redistributions in binary form must reproduce the above copyright *)
(* notice, this list of conditions and the following disclaimer in *)
(* the documentation and/or other materials provided with the *)
(* distribution. *)
(* *)
(* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' *)
(* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED *)
(* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A *)
(* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR *)
(* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, *)
(* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT *)
(* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF *)
(* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND *)
(* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, *)
(* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT *)
(* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF *)
(* SUCH DAMAGE. *)
(**************************************************************************)
open Ast_util
open Jib
open Jib_util
let optimize_unit instrs =
let unit_cval cval =
match cval_ctyp cval with
| CT_unit -> (F_lit V_unit, CT_unit)
| _ -> cval
in
let unit_instr = function
| I_aux (I_funcall (clexp, extern, id, args), annot) as instr ->
begin match clexp_ctyp clexp with
| CT_unit ->
I_aux (I_funcall (CL_void, extern, id, List.map unit_cval args), annot)
| _ -> instr
end
| I_aux (I_copy (clexp, cval), annot) as instr ->
begin match clexp_ctyp clexp with
| CT_unit ->
I_aux (I_copy (CL_void, unit_cval cval), annot)
| _ -> instr
end
| I_aux (I_alias (clexp, cval), annot) as instr ->
begin match clexp_ctyp clexp with
| CT_unit ->
I_aux (I_alias (CL_void, unit_cval cval), annot)
| _ -> instr
end
| instr -> instr
in
let non_pointless_copy (I_aux (aux, annot)) =
match aux with
| I_copy (CL_void, _) -> false
| _ -> true
in
filter_instrs non_pointless_copy (map_instr_list unit_instr instrs)
let flat_counter = ref 0
let flat_id () =
let id = mk_id ("local#" ^ string_of_int !flat_counter) in
incr flat_counter;
id
let rec flatten_instrs = function
| I_aux (I_decl (ctyp, decl_id), aux) :: instrs ->
let fid = flat_id () in
I_aux (I_decl (ctyp, fid), aux) :: flatten_instrs (instrs_rename decl_id fid instrs)
| I_aux ((I_block block | I_try_block block), _) :: instrs ->
flatten_instrs block @ flatten_instrs instrs
| I_aux (I_if (cval, then_instrs, else_instrs, _), _) :: instrs ->
let then_label = label "then_" in
let endif_label = label "endif_" in
[ijump cval then_label]
@ flatten_instrs else_instrs
@ [igoto endif_label]
@ [ilabel then_label]
@ flatten_instrs then_instrs
@ [ilabel endif_label]
@ flatten_instrs instrs
| I_aux (I_comment _, _) :: instrs -> flatten_instrs instrs
| instr :: instrs -> instr :: flatten_instrs instrs
| [] -> []
let flatten_cdef =
function
| CDEF_fundef (function_id, heap_return, args, body) ->
flat_counter := 0;
CDEF_fundef (function_id, heap_return, args, flatten_instrs body)
| CDEF_let (n, bindings, instrs) ->
flat_counter := 0;
CDEF_let (n, bindings, flatten_instrs instrs)
| cdef -> cdef
|
