{
    $Id$
    Copyright (c) 2003 by Florian Klaempfl

    ARM specific calling conventions

    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.
 ****************************************************************************
}
{ ARM specific calling conventions are handled by this unit
}
unit cpupara;

{$i fpcdefs.inc}

  interface

    uses
       globtype,
       aasmtai,
       cpubase,
       symconst,symbase,symtype,symdef,paramgr;

    type
       tarmparamanager = class(tparamanager)
          function push_addr_param(def : tdef;calloption : tproccalloption) : boolean;override;
          function getintparaloc(calloption : tproccalloption; nr : longint) : tparalocation;override;
          // procedure freeintparaloc(list: taasmoutput; nr : longint); override;
          procedure create_paraloc_info(p : tabstractprocdef; side: tcallercallee);override;
       end;

  implementation

    uses
       verbose,systems,
       cpuinfo,cginfo,cgbase,
       rgobj,
       defutil,symsym;

    function tarmparamanager.getintparaloc(calloption : tproccalloption; nr : longint) : tparalocation;
      begin
         fillchar(result,sizeof(tparalocation),0);
         if nr<1 then
           internalerror(2002070801)
         else if nr<=4 then
           begin
              result.loc:=LOC_REGISTER;
              result.register:=newreg(R_INTREGISTER,RS_R0+nr,R_SUBWHOLE);
           end
         else
           begin
              result.loc:=LOC_REFERENCE;
              result.reference.index:=NR_STACK_POINTER_REG;
              result.reference.offset:=(nr-4)*4;
           end;
         result.size := OS_INT;
      end;

{
    procedure tarmparamanager.freeintparaloc(list: taasmoutput; nr : longint);

      var
        r: tregister;

      begin
         if nr<1 then
           internalerror(2003060401)
         else if nr<=4 then
           begin
             r:=newreg(R_INTREGISTER,RS_R0+nr,R_SUBWHOLE);
             rg.ungetregisterint(list,r);
           end;
      end;
}

    function getparaloc(p : tdef) : tcgloc;
      begin
         { Later, the LOC_REFERENCE is in most cases changed into LOC_REGISTER
           if push_addr_param for the def is true
         }
         case p.deftype of
            orddef:
              getparaloc:=LOC_REGISTER;
            floatdef:
              getparaloc:=LOC_FPUREGISTER;
            enumdef:
              getparaloc:=LOC_REGISTER;
            pointerdef:
              getparaloc:=LOC_REGISTER;
            formaldef:
              getparaloc:=LOC_REGISTER;
            classrefdef:
              getparaloc:=LOC_REGISTER;
            recorddef:
              getparaloc:=LOC_REFERENCE;
            objectdef:
              if is_object(p) then
                getparaloc:=LOC_REFERENCE
              else
                getparaloc:=LOC_REGISTER;
            stringdef:
              if is_shortstring(p) or is_longstring(p) then
                getparaloc:=LOC_REFERENCE
              else
                getparaloc:=LOC_REGISTER;
            procvardef:
              if (po_methodpointer in tprocvardef(p).procoptions) then
                getparaloc:=LOC_REFERENCE
              else
                getparaloc:=LOC_REGISTER;
            filedef:
              getparaloc:=LOC_REGISTER;
            arraydef:
              getparaloc:=LOC_REFERENCE;
            setdef:
              if is_smallset(p) then
                getparaloc:=LOC_REGISTER
              else
                getparaloc:=LOC_REFERENCE;
            variantdef:
              getparaloc:=LOC_REFERENCE;
            { avoid problems with errornous definitions }
            errordef:
              getparaloc:=LOC_REGISTER;
            else
              internalerror(2002071001);
         end;
      end;

    function tarmparamanager.push_addr_param(def : tdef;calloption : tproccalloption) : boolean;
      begin
        case def.deftype of
          recorddef:
            push_addr_param:=true;
          arraydef:
            push_addr_param:=(tarraydef(def).highrange>=tarraydef(def).lowrange) or
                             is_open_array(def) or
                             is_array_of_const(def) or
                             is_array_constructor(def);
          setdef :
            push_addr_param:=(tsetdef(def).settype<>smallset);
          stringdef :
            push_addr_param:=tstringdef(def).string_typ in [st_shortstring,st_longstring];
          procvardef :
            push_addr_param:=po_methodpointer in tprocvardef(def).procoptions;
          else
            push_addr_param:=inherited push_addr_param(def,calloption);
        end;
      end;

    procedure tarmparamanager.create_paraloc_info(p : tabstractprocdef; side: tcallercallee);

      var
         nextintreg,nextfloatreg,nextmmreg : tregister;
         paradef : tdef;
         paraloc : tparalocation;
         stack_offset : aword;
         hp : tparaitem;
         loc : tcgloc;
         is_64bit: boolean;

      procedure assignintreg;

        begin
           if nextintreg<=NR_R3 then
             begin
                paraloc.loc:=LOC_REGISTER;
                paraloc.register:=newreg(R_INTREGISTER,nextintreg,R_SUBWHOLE);;
                inc(nextintreg);
             end
           else
              begin
                 paraloc.loc:=LOC_REFERENCE;
                 paraloc.reference.index:=NR_STACK_POINTER_REG;
                 paraloc.reference.offset:=stack_offset;
                 inc(stack_offset,4);
             end;
        end;

      begin
         { zero alignment bytes }
         fillchar(nextintreg,sizeof(nextintreg),0);
         fillchar(nextfloatreg,sizeof(nextfloatreg),0);
         fillchar(nextmmreg,sizeof(nextmmreg),0);
         nextintreg:=RS_R0;
         nextfloatreg:=RS_F0;
         nextmmreg:=RS_D0;
         stack_offset:=0;

         { frame pointer for nested procedures? }
         { inc(nextintreg);                     }
         { constructor? }
         { destructor? }
         hp:=tparaitem(p.para.first);
         while assigned(hp) do
           begin
              if (hp.paratyp in [vs_var,vs_out]) then
                begin
                  paradef := voidpointertype.def;
                  loc := LOC_REGISTER;
                end
              else
                begin
                  paradef := hp.paratype.def;
                  loc:=getparaloc(paradef);
                end;
              { make sure all alignment bytes are 0 as well }
              fillchar(paraloc,sizeof(paraloc),0);
              case loc of
                 LOC_REGISTER:
                   begin
                      paraloc.size := def_cgsize(paradef);
                      { for things like formaldef }
                      if paraloc.size = OS_NO then
                        paraloc.size := OS_ADDR;
                      is_64bit := paraloc.size in [OS_64,OS_S64];
                      if nextintreg<=(RS_R3-ord(is_64bit)) then
                        begin
                           paraloc.loc:=LOC_REGISTER;
		           if is_64bit then
                             begin
                               paraloc.registerhigh:=newreg(R_INTREGISTER,nextintreg,R_SUBWHOLE);;
                               inc(nextintreg);
                             end;
                           paraloc.registerlow:=newreg(R_INTREGISTER,nextintreg,R_SUBWHOLE);;
                           inc(nextintreg);
                        end
                      else
                         begin
                            nextintreg:=RS_R4;
                            paraloc.loc:=LOC_REFERENCE;
                            paraloc.reference.index:=NR_STACK_POINTER_REG;
                            paraloc.reference.offset:=stack_offset;
                            if not is_64bit then
                              inc(stack_offset,4)
                            else
                              inc(stack_offset,8);
                        end;
                   end;
                 LOC_FPUREGISTER:
                   begin
                      paraloc.size:=def_cgsize(paradef);
                      if nextfloatreg<=RS_F3 then
                        begin
                           paraloc.loc:=LOC_FPUREGISTER;
                           paraloc.register:=newreg(R_FPUREGISTER,nextfloatreg,R_SUBWHOLE);
                           inc(nextfloatreg);
                        end
                      else
                         begin
                            {!!!!!!!}
                            paraloc.size:=def_cgsize(paradef);
                            internalerror(2002071004);
                        end;
                   end;
                 LOC_REFERENCE:
                   begin
                      paraloc.size:=OS_ADDR;
                      if push_addr_param(paradef,p.proccalloption) or
                        is_open_array(paradef) or
                        is_array_of_const(paradef) then
                        assignintreg
                      else
                        begin
                           paraloc.loc:=LOC_REFERENCE;
                           paraloc.reference.index:=NR_STACK_POINTER_REG;
                           paraloc.reference.offset:=stack_offset;
                           inc(stack_offset,hp.paratype.def.size);
                        end;
                   end;
                 else
                   internalerror(2002071002);
              end;
              if side=calleeside then
                begin
                  if (paraloc.loc = LOC_REFERENCE) then
                    paraloc.reference.offset := tvarsym(hp.parasym).adjusted_address;
                end;
              hp.paraloc[side]:=paraloc;
              hp:=tparaitem(hp.next);
           end;
        { Function return }
        fillchar(paraloc,sizeof(tparalocation),0);
        paraloc.size:=def_cgsize(p.rettype.def);
        { Return in FPU register? }
        if p.rettype.def.deftype=floatdef then
          begin
            paraloc.loc:=LOC_FPUREGISTER;
            paraloc.register:=NR_FPU_RESULT_REG;
          end
        else
         { Return in register? }
         if not ret_in_param(p.rettype.def,p.proccalloption) then
          begin
            paraloc.loc:=LOC_REGISTER;
            if paraloc.size in [OS_64,OS_S64] then
              begin
                paraloc.register64.reglo:=NR_FUNCTION_RETURN64_LOW_REG;
                paraloc.register64.reghi:=NR_FUNCTION_RETURN64_HIGH_REG;
              end
            else
              paraloc.register:=NR_FUNCTION_RETURN_REG;
          end
        else
          begin
            paraloc.loc:=LOC_REFERENCE;
          end;
        p.funcret_paraloc[side]:=paraloc;
      end;

begin
   paramanager:=tarmparamanager.create;
end.
{
  $Log$
  Revision 1.7  2003-09-11 11:55:00  florian
    * improved arm code generation
    * move some protected and private field around
    * the temp. register for register parameters/arguments are now released
      before the move to the parameter register is done. This improves
      the code in a lot of cases.

  Revision 1.6  2003/09/09 12:53:40  florian
    * some assembling problems fixed
    * improved loadaddr_ref_reg

  Revision 1.5  2003/09/05 23:57:01  florian
    * arm is working again as before the new register naming scheme was implemented

  Revision 1.4  2003/09/04 00:15:29  florian
    * first bunch of adaptions of arm compiler for new register type

  Revision 1.3  2003/08/27 00:27:56  florian
    + same procedure as very day: today's work on arm

  Revision 1.2  2003/08/16 13:23:01  florian
    * several arm related stuff fixed

  Revision 1.1  2003/07/21 16:35:30  florian
    * very basic stuff for the arm
}