fpc/compiler/optdfa.pas

{
    DFA

    Copyright (c) 2007 by Florian Klaempfl

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 ****************************************************************************
}
unit optdfa;

{$i fpcdefs.inc}

  interface

    uses
      node;

    procedure createoptinfo(node : tnode);

  implementation

    uses
      globtype,globals,
      cpuinfo,
      nutils,
      nbas,nflw,ncon,ninl,ncal,
      optutils;


    function initnodes(var n:tnode; arg: pointer) : foreachnoderesult;
      begin
        { node worth to add? }
        if (node_complexity(n)>1) and (tstoreddef(n.resultdef).is_intregable or tstoreddef(n.resultdef).is_fpuregable) then
          begin
            plists(arg)^.nodelist.Add(n);
            plists(arg)^.locationlist.Add(@n);
            result:=fen_false;
          end
        else
          result:=fen_norecurse_false;
      end;




    {
      x:=f;         read: [f]

      while x do    read: []

        a:=b;       read: [a,b,d]  def: [a]       life:  read*def=[a]
          c:=d;     read: [a,d]    def: [a,c]     life:  read*def=[a]
            e:=a;   read: [a]      def: [a,c,e]   life:  read*def=[a]


      function f(b,d,x : type) : type;

        begin
          while x do        alive: b,d,x
            begin
              a:=b;         alive: b,d,x
              c:=d;         alive: a,d,x
              e:=a+c;       alive: a,c,x
              dec(x);       alive: c,e,x
            end;
          result:=c+e;      alive: c,e
        end;                alive: result

    }

    type
      tdfainfo = record
        definitionlist : tfplist;
        lifelist : tfplist;
      end;

    procedure createdfainfo(node : tnode);
      begin
        { first, add controll flow information }
        SetNodeSucessors(node);
        { now, collect life information }

      end;


end.