freepascal.compiler/compiler/m68k/cgcpu.pas

{
    Copyright (c) 1998-2002 by the FPC team

    This unit implements the code generator for the 680x0

    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.

 ****************************************************************************
}
{$WARNINGS OFF}
unit cgcpu;

{$i fpcdefs.inc}

  interface

    uses
       cgbase,cgobj,globtype,
       aasmbase,aasmtai,aasmdata,aasmcpu,
       cpubase,cpuinfo,
       parabase,cpupara,
       node,symconst,symtype,symdef,
       cgutils,cg64f32;

    type
      tcg68k = class(tcg)
        procedure init_register_allocators;override;
        procedure done_register_allocators;override;

        procedure a_param_reg(list : TAsmList;size : tcgsize;r : tregister;const cgpara : tcgpara);override;
        procedure a_param_const(list : TAsmList;size : tcgsize;a : aint;const cgpara : tcgpara);override;
        procedure a_param_ref(list : TAsmList;size : tcgsize;const r : treference;const cgpara : tcgpara);override;
        procedure a_paramaddr_ref(list : TAsmList;const r : treference;const cgpara : tcgpara);override;

        procedure a_call_name(list : TAsmList;const s : string);override;
        procedure a_call_reg(list : TAsmList;reg : tregister);override;

        procedure a_load_const_reg(list : TAsmList;size : tcgsize;a : aint;register : tregister);override;
        procedure a_load_const_ref(list : TAsmList; tosize: tcgsize; a : aint;const ref : treference);override;

        procedure a_load_reg_ref(list : TAsmList;fromsize,tosize : tcgsize;register : tregister;const ref : treference);override;
        procedure a_load_reg_reg(list : TAsmList;fromsize,tosize : tcgsize;reg1,reg2 : tregister);override;
        procedure a_load_ref_reg(list : TAsmList;fromsize,tosize : tcgsize;const ref : treference;register : tregister);override;
        procedure a_load_ref_ref(list : TAsmList;fromsize,tosize : tcgsize;const sref : treference;const dref : treference);override;

        procedure a_loadaddr_ref_reg(list : TAsmList;const ref : treference;r : tregister);override;
        procedure a_loadfpu_reg_reg(list: TAsmList; fromsize, tosize: tcgsize; reg1, reg2: tregister); override;
        procedure a_loadfpu_ref_reg(list: TAsmList; fromsize, tosize: tcgsize; const ref: treference; reg: tregister); override;
        procedure a_loadfpu_reg_ref(list: TAsmList; fromsize, tosize: tcgsize; reg: tregister; const ref: treference); override;

        procedure a_loadmm_reg_reg(list: TAsmList;fromsize,tosize : tcgsize; reg1, reg2: tregister;shuffle : pmmshuffle); override;
        procedure a_loadmm_ref_reg(list: TAsmList;fromsize,tosize : tcgsize; const ref: treference; reg: tregister;shuffle : pmmshuffle); override;
        procedure a_loadmm_reg_ref(list: TAsmList;fromsize,tosize : tcgsize; reg: tregister; const ref: treference;shuffle : pmmshuffle); override;
        procedure a_parammm_reg(list: TAsmList; size: tcgsize; reg: tregister;const locpara : TCGPara;shuffle : pmmshuffle); override;

        procedure a_op_const_reg(list : TAsmList; Op: TOpCG; size: tcgsize; a: aint; reg: TRegister); override;
//        procedure a_op_const_ref(list : TAsmList; Op: TOpCG; size: TCGSize; a: aint; const ref: TReference); override;
        procedure a_op_reg_reg(list : TAsmList; Op: TOpCG; size: TCGSize; reg1, reg2: TRegister); override;

        procedure a_cmp_const_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;a : aint;reg : tregister;
          l : tasmlabel);override;
        procedure a_cmp_reg_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;reg1,reg2 : tregister;l : tasmlabel); override;
        procedure a_jmp_always(list : TAsmList;l: tasmlabel); override;
        procedure a_jmp_flags(list : TAsmList;const f : TResFlags;l: tasmlabel); override;
        procedure g_flags2reg(list: TAsmList; size: TCgSize; const f: tresflags; reg: TRegister); override;

        procedure g_concatcopy(list : TAsmList;const source,dest : treference;len : aint);override;
        { generates overflow checking code for a node }
        procedure g_overflowcheck(list: TAsmList; const l:tlocation; def:tdef); override;
        procedure g_copyvaluepara_openarray(list : TAsmList;const ref:treference;const lenloc:tlocation;elesize:aint;destreg:tregister);override;

        procedure g_proc_entry(list : TAsmList;localsize : longint;nostackframe:boolean);override;
        procedure g_proc_exit(list : TAsmList;parasize:longint;nostackframe:boolean);override;

//        procedure g_restore_frame_pointer(list : TAsmList);override;
//        procedure g_return_from_proc(list : TAsmList;parasize : aint);override;
        procedure g_restore_standard_registers(list:TAsmList);override;
        procedure g_save_standard_registers(list:TAsmList);override;

//        procedure g_save_all_registers(list : TAsmList);override;
//        procedure g_restore_all_registers(list : TAsmList;const funcretparaloc:TCGPara);override;

        procedure g_intf_wrapper(list: TAsmList; procdef: tprocdef; const labelname: string; ioffset: longint);override;

     protected
        function fixref(list: TAsmList; var ref: treference): boolean;
     private
        { # Sign or zero extend the register to a full 32-bit value.
            The new value is left in the same register.
        }
        procedure sign_extend(list: TAsmList;_oldsize : tcgsize; reg: tregister);
        procedure a_jmp_cond(list : TAsmList;cond : TOpCmp;l: tasmlabel);

     end;

     tcg64f68k = class(tcg64f32)
       procedure a_op64_reg_reg(list : TAsmList;op:TOpCG; size: tcgsize; regsrc,regdst : tregister64);override;
       procedure a_op64_const_reg(list : TAsmList;op:TOpCG; size: tcgsize; value : int64;regdst : tregister64);override;
     end;

     { This function returns true if the reference+offset is valid.
       Otherwise extra code must be generated to solve the reference.

       On the m68k, this verifies that the reference is valid
       (e.g : if index register is used, then the max displacement
        is 256 bytes, if only base is used, then max displacement
        is 32K
     }
     function isvalidrefoffset(const ref: treference): boolean;

    const
      TCGSize2OpSize: Array[tcgsize] of topsize =
        (S_NO,S_B,S_W,S_L,S_L,S_NO,S_B,S_W,S_L,S_L,S_NO,
         S_FS,S_FD,S_FX,S_NO,S_NO,
         S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO);


  implementation

    uses
       globals,verbose,systems,cutils,
       symsym,defutil,paramgr,procinfo,
       rgobj,tgobj,rgcpu,fmodule;


    const
      { opcode table lookup }
      topcg2tasmop: Array[topcg] of tasmop =
      (
       A_NONE,
       A_MOVE,
       A_ADD,
       A_AND,
       A_DIVU,
       A_DIVS,
       A_MULS,
       A_MULU,
       A_NEG,
       A_NOT,
       A_OR,
       A_ASR,
       A_LSL,
       A_LSR,
       A_SUB,
       A_EOR
      );


      TOpCmp2AsmCond: Array[topcmp] of TAsmCond =
      (
       C_NONE,
       C_EQ,
       C_GT,
       C_LT,
       C_GE,
       C_LE,
       C_NE,
       C_LS,
       C_CS,
       C_CC,
       C_HI
      );


     function isvalidrefoffset(const ref: treference): boolean;
      begin
         isvalidrefoffset := true;
         if ref.index <> NR_NO then
           begin
             if ref.base <> NR_NO then
                internalerror(20020814);
             if (ref.offset < low(shortint)) or (ref.offset > high(shortint)) then
                isvalidrefoffset := false
           end
         else
           begin
             if (ref.offset < low(smallint)) or (ref.offset > high(smallint)) then
                isvalidrefoffset := false;
           end;
      end;


{****************************************************************************}
{                               TCG68K                                       }
{****************************************************************************}


    function use_push(const cgpara:tcgpara):boolean;
      begin
        result:=(not use_fixed_stack) and
                assigned(cgpara.location) and
                (cgpara.location^.loc=LOC_REFERENCE) and
                (cgpara.location^.reference.index=NR_STACK_POINTER_REG);
      end;


    procedure tcg68k.init_register_allocators;
      begin
        inherited init_register_allocators;
        rg[R_INTREGISTER]:=trgcpu.create(R_INTREGISTER,R_SUBWHOLE,
          [RS_D0,RS_D1,RS_D2,RS_D3,RS_D4,RS_D5,RS_D6,RS_D7],
          first_int_imreg,[]);
        rg[R_ADDRESSREGISTER]:=trgcpu.create(R_ADDRESSREGISTER,R_SUBWHOLE,
          [RS_A0,RS_A1,RS_A2,RS_A3,RS_A4,RS_A5,RS_A6],
          first_addr_imreg,[]);
        rg[R_FPUREGISTER]:=trgcpu.create(R_FPUREGISTER,R_SUBNONE,
          [RS_FP0,RS_FP1,RS_FP2,RS_FP3,RS_FP4,RS_FP5,RS_FP6,RS_FP7],
          first_fpu_imreg,[]);
      end;


    procedure tcg68k.done_register_allocators;
      begin
        rg[R_INTREGISTER].free;
        rg[R_FPUREGISTER].free;
        rg[R_ADDRESSREGISTER].free;
        inherited done_register_allocators;
      end;


    procedure tcg68k.a_param_reg(list : TAsmList;size : tcgsize;r : tregister;const cgpara : tcgpara);
      var
        pushsize : tcgsize;
        ref : treference;
      begin
{$ifdef DEBUG_CHARLIE}
        writeln('a_param_reg');
{$endif DEBUG_CHARLIE}
        { it's probably necessary to port this from x86 later, or provide an m68k solution (KB) }
{$WARNING FIX ME! check_register_size()}
        // check_register_size(size,r);
        if use_push(cgpara) then
          begin
            cgpara.check_simple_location;
            if tcgsize2size[cgpara.location^.size]>cgpara.alignment then
              pushsize:=cgpara.location^.size
            else
              pushsize:=int_cgsize(cgpara.alignment);

            reference_reset_base(ref, NR_STACK_POINTER_REG, 0);
            ref.direction := dir_dec;
            list.concat(taicpu.op_reg_ref(A_MOVE,tcgsize2opsize[pushsize],makeregsize(list,r,pushsize),ref));
          end
        else
          inherited a_param_reg(list,size,r,cgpara);
      end;


    procedure tcg68k.a_param_const(list : TAsmList;size : tcgsize;a : aint;const cgpara : tcgpara);
      var
        pushsize : tcgsize;
        ref : treference;
      begin
{$ifdef DEBUG_CHARLIE}
        writeln('a_param_const');
{$endif DEBUG_CHARLIE}
        { remove "not" to trigger the location bug (KB) }
        if use_push(cgpara) then
          begin
            cgpara.check_simple_location;
            if tcgsize2size[cgpara.location^.size]>cgpara.alignment then
              pushsize:=cgpara.location^.size
            else
              pushsize:=int_cgsize(cgpara.alignment);

            reference_reset_base(ref, NR_STACK_POINTER_REG, 0);
            ref.direction := dir_dec;
            list.concat(taicpu.op_const_ref(A_MOVE,tcgsize2opsize[pushsize],a,ref));
          end
        else
          inherited a_param_const(list,size,a,cgpara);
      end;


    procedure tcg68k.a_param_ref(list : TAsmList;size : tcgsize;const r : treference;const cgpara : tcgpara);

        procedure pushdata(paraloc:pcgparalocation;ofs:aint);
        var
          pushsize : tcgsize;
          tmpreg   : tregister;
          href     : treference;
          ref      : treference;
        begin
          if not assigned(paraloc) then
            exit;
{$WARNING FIX ME!!! this also triggers location bug }
          {if (paraloc^.loc<>LOC_REFERENCE) or
             (paraloc^.reference.index<>NR_STACK_POINTER_REG) or
             (tcgsize2size[paraloc^.size]>sizeof(aint)) then
            internalerror(200501162);}

          { Pushes are needed in reverse order, add the size of the
            current location to the offset where to load from. This
            prevents wrong calculations for the last location when
            the size is not a power of 2 }
          if assigned(paraloc^.next) then
            pushdata(paraloc^.next,ofs+tcgsize2size[paraloc^.size]);
          { Push the data starting at ofs }
          href:=r;
          inc(href.offset,ofs);
          if tcgsize2size[paraloc^.size]>cgpara.alignment then
            pushsize:=paraloc^.size
          else
            pushsize:=int_cgsize(cgpara.alignment);

          reference_reset_base(ref, NR_STACK_POINTER_REG, 0);
          ref.direction := dir_dec;

          if tcgsize2size[paraloc^.size]<cgpara.alignment then
            begin
              tmpreg:=getintregister(list,pushsize);
              a_load_ref_reg(list,paraloc^.size,pushsize,href,tmpreg);
              list.concat(taicpu.op_reg_ref(A_MOVE,tcgsize2opsize[pushsize],tmpreg,ref));
            end
          else
              list.concat(taicpu.op_ref_ref(A_MOVE,tcgsize2opsize[pushsize],href,ref));
        end;

      var
        len : aint;
        href : treference;
      begin
{$ifdef DEBUG_CHARLIE}
        writeln('a_param_ref');
{$endif DEBUG_CHARLIE}

        { cgpara.size=OS_NO requires a copy on the stack }
        if use_push(cgpara) then
          begin
            { Record copy? }
            if (cgpara.size in [OS_NO,OS_F64]) or (size=OS_NO) then
              begin
                cgpara.check_simple_location;
                len:=align(cgpara.intsize,cgpara.alignment);
                g_stackpointer_alloc(list,len);
                reference_reset_base(href,NR_STACK_POINTER_REG,0);
                g_concatcopy(list,r,href,len);
              end
            else
              begin
                if tcgsize2size[cgpara.size]<>tcgsize2size[size] then
                  internalerror(200501161);
                { We need to push the data in reverse order,
                  therefor we use a recursive algorithm }
                pushdata(cgpara.location,0);
              end
          end
        else
          inherited a_param_ref(list,size,r,cgpara);
      end;


    procedure tcg68k.a_paramaddr_ref(list : TAsmList;const r : treference;const cgpara : tcgpara);
      var
        tmpreg : tregister;
        opsize : topsize;
      begin
{$ifdef DEBUG_CHARLIE}
        writeln('a_paramaddr_ref');
{$endif DEBUG_CHARLIE}
        with r do
          begin
            { i suppose this is not required for m68k (KB) }
//            if (segment<>NR_NO) then
//              cgmessage(cg_e_cant_use_far_pointer_there);
            if not use_push(cgpara) then
              begin
                cgpara.check_simple_location;
                opsize:=tcgsize2opsize[OS_ADDR];
                if (segment=NR_NO) and (base=NR_NO) and (index=NR_NO) then
                  begin
                    if assigned(symbol) then
//                      list.concat(Taicpu.Op_sym_ofs(A_PUSH,opsize,symbol,offset))
                    else;
//                      list.concat(Taicpu.Op_const(A_PUSH,opsize,offset));
                  end
                else if (segment=NR_NO) and (base=NR_NO) and (index<>NR_NO) and
                        (offset=0) and (scalefactor=0) and (symbol=nil) then
//                  list.concat(Taicpu.Op_reg(A_PUSH,opsize,index))
                else if (segment=NR_NO) and (base<>NR_NO) and (index=NR_NO) and
                        (offset=0) and (symbol=nil) then
//                  list.concat(Taicpu.Op_reg(A_PUSH,opsize,base))
                else
                  begin
                    tmpreg:=getaddressregister(list);
                    a_loadaddr_ref_reg(list,r,tmpreg);
//                    list.concat(taicpu.op_reg(A_PUSH,opsize,tmpreg));
                  end;
              end
            else
              inherited a_paramaddr_ref(list,r,cgpara);
          end;
      end;



    function tcg68k.fixref(list: TAsmList; var ref: treference): boolean;

       begin
         result:=false;
         { The Coldfire and MC68020+ have extended
           addressing capabilities with a 32-bit
           displacement.
         }
         if (current_settings.cputype<>cpu_MC68000) then
           exit;
         if (ref.base<>NR_NO) then
           begin
             if (ref.index <> NR_NO) and assigned(ref.symbol) then
                internalerror(20020814);
             { base + reg }
             if ref.index <> NR_NO then
                begin
                   { base + reg + offset }
                   if (ref.offset < low(shortint)) or (ref.offset > high(shortint)) then
                     begin
                        list.concat(taicpu.op_const_reg(A_ADD,S_L,ref.offset,ref.base));
                        fixref := true;
                        ref.offset := 0;
                        exit;
                     end;
                end
             else
             { base + offset }
             if (ref.offset < low(smallint)) or (ref.offset > high(smallint)) then
               begin
                 list.concat(taicpu.op_const_reg(A_ADD,S_L,ref.offset,ref.base));
                 fixref := true;
                 ref.offset := 0;
                 exit;
               end;
           end;
       end;



    procedure tcg68k.a_call_name(list : TAsmList;const s : string);

      begin
        list.concat(taicpu.op_sym(A_JSR,S_NO,current_asmdata.RefAsmSymbol(s)));
      end;


    procedure tcg68k.a_call_reg(list : TAsmList;reg : tregister);
     var
       href : treference;
     begin
       reference_reset_base(href, reg, 0);
       //!!! a_call_ref(list,href);
     end;



    procedure tcg68k.a_load_const_reg(list : TAsmList;size : tcgsize;a : aint;register : tregister);
      begin
{$ifdef DEBUG_CHARLIE}
        writeln('a_load_const_reg');
{$endif DEBUG_CHARLIE}

        if getregtype(register)=R_ADDRESSREGISTER then
         begin
           list.concat(taicpu.op_const_reg(A_MOVE,S_L,longint(a),register))
         end
        else
        if a = 0 then
           list.concat(taicpu.op_reg(A_CLR,S_L,register))
        else
         begin
           if (longint(a) >= low(shortint)) and (longint(a) <= high(shortint)) then
              list.concat(taicpu.op_const_reg(A_MOVEQ,S_L,longint(a),register))
           else
              list.concat(taicpu.op_const_reg(A_MOVE,S_L,longint(a),register))
         end;
      end;

    procedure tcg68k.a_load_const_ref(list : TAsmList; tosize: tcgsize; a : aint;const ref : treference);
      begin
{$ifdef DEBUG_CHARLIE}
        writeln('a_load_const_ref');
{$endif DEBUG_CHARLIE}

        list.concat(taicpu.op_const_ref(A_MOVE,S_L,longint(a),ref));
      end;


    procedure tcg68k.a_load_reg_ref(list : TAsmList;fromsize,tosize : tcgsize;register : tregister;const ref : treference);
      var
       href : treference;
      begin
         href := ref;
         fixref(list,href);
{$ifdef DEBUG_CHARLIE}
         writeln('a_load_reg_ref');
{$endif DEBUG_CHARLIE}
         { move to destination reference }
         list.concat(taicpu.op_reg_ref(A_MOVE,TCGSize2OpSize[fromsize],register,href));
      end;


    procedure tcg68k.a_load_ref_ref(list : TAsmList;fromsize,tosize : tcgsize;const sref : treference;const dref : treference);
      var
        aref: treference;
        bref: treference;
      begin
        aref := sref;
        bref := dref;
        fixref(list,aref);
        fixref(list,bref);
{$ifdef DEBUG_CHARLIE}
        writeln('a_load_ref_ref');
{$endif DEBUG_CHARLIE}
        list.concat(taicpu.op_ref_ref(A_MOVE,TCGSize2OpSize[fromsize],aref,bref));
      end;


    procedure tcg68k.a_load_reg_reg(list : TAsmList;fromsize,tosize : tcgsize;reg1,reg2 : tregister);
      begin
         { move to destination register }
         list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg1,reg2));
         { zero/sign extend register to 32-bit }
         sign_extend(list, fromsize, reg2);
      end;


    procedure tcg68k.a_load_ref_reg(list : TAsmList;fromsize,tosize : tcgsize;const ref : treference;register : tregister);
      var
       href : treference;
      begin
         href := ref;
         fixref(list,href);
         list.concat(taicpu.op_ref_reg(A_MOVE,TCGSize2OpSize[fromsize],href,register));
         { extend the value in the register }
         sign_extend(list, tosize, register);
      end;


    procedure tcg68k.a_loadaddr_ref_reg(list : TAsmList;const ref : treference;r : tregister);
     var
       href : treference;
//       p: pointer;
      begin
         {$WARNING FIX ME!!! take a look on this mess again...}
//        if getregtype(r)=R_ADDRESSREGISTER then
//          begin
//            writeln('address reg?!?');
//            p:=nil; dword(p^):=0; {DEBUG CODE... :D )
//            internalerror(2002072901);
//          end;
        href:=ref;
        fixref(list, href);
        list.concat(taicpu.op_ref_reg(A_LEA,S_L,href,r));
      end;


    procedure tcg68k.a_loadfpu_reg_reg(list: TAsmList; fromsize, tosize: tcgsize; reg1, reg2: tregister);
      begin
        { in emulation mode, only 32-bit single is supported }
        if cs_fp_emulation in current_settings.moduleswitches then
          list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg1,reg2))
        else
          list.concat(taicpu.op_reg_reg(A_FMOVE,tcgsize2opsize[tosize],reg1,reg2));
      end;


    procedure tcg68k.a_loadfpu_ref_reg(list: TAsmList; fromsize, tosize: tcgsize; const ref: treference; reg: tregister);
     var
      opsize : topsize;
      href : treference;
      tmpreg : tregister;
      begin
        opsize := tcgsize2opsize[fromsize];
        { extended is not supported, since it is not available on Coldfire }
        if opsize = S_FX then
          internalerror(20020729);
        href := ref;
        fixref(list,href);
        { in emulation mode, only 32-bit single is supported }
        if cs_fp_emulation in current_settings.moduleswitches then
           list.concat(taicpu.op_ref_reg(A_MOVE,S_L,href,reg))
        else
           begin
             list.concat(taicpu.op_ref_reg(A_FMOVE,opsize,href,reg));
             if (tosize < fromsize) then
               a_loadfpu_reg_reg(list,fromsize,tosize,reg,reg);
           end;
      end;

    procedure tcg68k.a_loadfpu_reg_ref(list: TAsmList; fromsize,tosize: tcgsize; reg: tregister; const ref: treference);
      var
       opsize : topsize;
      begin
        opsize := tcgsize2opsize[tosize];
        { extended is not supported, since it is not available on Coldfire }
        if opsize = S_FX then
          internalerror(20020729);
        { in emulation mode, only 32-bit single is supported }
        if cs_fp_emulation in current_settings.moduleswitches then
          list.concat(taicpu.op_reg_ref(A_MOVE,S_L,reg, ref))
        else
          list.concat(taicpu.op_reg_ref(A_FMOVE,opsize,reg, ref));
      end;


    procedure tcg68k.a_loadmm_reg_reg(list: TAsmList;fromsize,tosize : tcgsize; reg1, reg2: tregister;shuffle : pmmshuffle);
      begin
        internalerror(20020729);
      end;


    procedure tcg68k.a_loadmm_ref_reg(list: TAsmList;fromsize,tosize : tcgsize; const ref: treference; reg: tregister;shuffle : pmmshuffle);
      begin
        internalerror(20020729);
      end;


    procedure tcg68k.a_loadmm_reg_ref(list: TAsmList;fromsize,tosize : tcgsize; reg: tregister; const ref: treference;shuffle : pmmshuffle);
      begin
        internalerror(20020729);
      end;


    procedure tcg68k.a_parammm_reg(list: TAsmList; size: tcgsize; reg: tregister;const locpara : TCGPara;shuffle : pmmshuffle);
      begin
        internalerror(20020729);
      end;


    procedure tcg68k.a_op_const_reg(list : TAsmList; Op: TOpCG; size: tcgsize; a: aint; reg: TRegister);
      var
       scratch_reg : tregister;
       scratch_reg2: tregister;
       opcode : tasmop;
       r,r2 : Tregister;
      begin
        optimize_op_const(op, a);
        opcode := topcg2tasmop[op];
        case op of
          OP_NONE :
            begin
              { Opcode is optimized away }
            end;
          OP_MOVE :
            begin
              { Optimized, replaced with a simple load }
              a_load_const_reg(list,size,a,reg);
            end;
          OP_ADD :
              begin
                if (a >= 1) and (a <= 8) then
                    list.concat(taicpu.op_const_reg(A_ADDQ,S_L,a, reg))
                else
                  begin
                    { all others, including coldfire }
                    list.concat(taicpu.op_const_reg(A_ADD,S_L,a, reg));
                  end;
              end;
          OP_AND,
          OP_OR:
              begin
                 list.concat(taicpu.op_const_reg(topcg2tasmop[op],S_L,longint(a), reg));
              end;
          OP_DIV :
              begin
                 internalerror(20020816);
              end;
          OP_IDIV :
              begin
                 internalerror(20020816);
              end;
          OP_IMUL :
              begin
                if current_settings.cputype = cpu_MC68000 then
                   begin
                     r:=NR_D0;
                     r2:=NR_D1;
                     cg.getcpuregister(list,NR_D0);
                     cg.getcpuregister(list,NR_D1);
                     list.concat(taicpu.op_const_reg(A_MOVE,S_L,a, r));
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg, r2));
                     cg.a_call_name(list,'FPC_MUL_LONGINT');
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,r, reg));
                     cg.ungetcpuregister(list,r);
                     cg.ungetcpuregister(list,r2);

                   end
                  else
                    begin
                      if (isaddressregister(reg)) then
                       begin
                         scratch_reg := getintregister(list,OS_INT);
                         list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg, scratch_reg));
                         list.concat(taicpu.op_const_reg(A_MULS,S_L,a,scratch_reg));
                         list.concat(taicpu.op_reg_reg(A_MOVE,S_L,scratch_reg,reg));
                       end
                      else
                         list.concat(taicpu.op_const_reg(A_MULS,S_L,a,reg));
                    end;
              end;
          OP_MUL :
              begin
                 if current_settings.cputype = cpu_MC68000 then
                   begin
                     r:=NR_D0;
                     r2:=NR_D1;
                     cg.getcpuregister(list,NR_D0);
                     cg.getcpuregister(list,NR_D1);
                     list.concat(taicpu.op_const_reg(A_MOVE,S_L,a, r));
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg, r2));
                     cg.a_call_name(list,'FPC_MUL_LONGWORD');
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,r, reg));
                     cg.ungetcpuregister(list,r);
                     cg.ungetcpuregister(list,r2);
                   end
                  else
                    begin
                      if (isaddressregister(reg)) then
                       begin
                         scratch_reg := getintregister(list,OS_INT);
                         list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg, scratch_reg));
                         list.concat(taicpu.op_const_reg(A_MULU,S_L,a,scratch_reg));
                         list.concat(taicpu.op_reg_reg(A_MOVE,S_L,scratch_reg,reg));
                       end
                      else
                         list.concat(taicpu.op_const_reg(A_MULU,S_L,a,reg));
                    end;
              end;
          OP_SAR,
          OP_SHL,
          OP_SHR :
              begin
                if (a >= 1) and (a <= 8) then
                 begin
                   { now allowed to shift an address register }
                   if (isaddressregister(reg)) then
                     begin
                       scratch_reg := getintregister(list,OS_INT);
                       list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg, scratch_reg));
                       list.concat(taicpu.op_const_reg(opcode,S_L,a, scratch_reg));
                       list.concat(taicpu.op_reg_reg(A_MOVE,S_L,scratch_reg,reg));
                     end
                   else
                     list.concat(taicpu.op_const_reg(opcode,S_L,a, reg));
                 end
                else
                 begin
                   { we must load the data into a register ... :() }
                   scratch_reg := cg.getintregister(list,OS_INT);
                   list.concat(taicpu.op_const_reg(A_MOVE,S_L,a, scratch_reg));
                   { again... since shifting with address register is not allowed }
                   if (isaddressregister(reg)) then
                     begin
                       scratch_reg2 := cg.getintregister(list,OS_INT);
                       list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg, scratch_reg2));
                       list.concat(taicpu.op_reg_reg(opcode,S_L,scratch_reg, scratch_reg2));
                       list.concat(taicpu.op_reg_reg(A_MOVE,S_L,scratch_reg2,reg));
                     end
                   else
                     list.concat(taicpu.op_reg_reg(opcode,S_L,scratch_reg, reg));
                 end;
              end;
          OP_SUB :
              begin
                if (a >= 1) and (a <= 8) then
                    list.concat(taicpu.op_const_reg(A_SUBQ,S_L,a,reg))
                else
                  begin
                    { all others, including coldfire }
                    list.concat(taicpu.op_const_reg(A_SUB,S_L,a, reg));
                  end;
              end;
          OP_XOR :
              begin
                list.concat(taicpu.op_const_reg(A_EORI,S_L,a, reg));
              end;
        else
            internalerror(20020729);
         end;
      end;

{
    procedure tcg68k.a_op_const_ref(list : TAsmList; Op: TOpCG; size: TCGSize; a: aint; const ref: TReference);
      var
        opcode: tasmop;
      begin
        writeln('a_op_const_ref');

        optimize_op_const(op, a);
        opcode := topcg2tasmop[op];
        case op of
          OP_NONE :
            begin
              { opcode was optimized away }
            end;
          OP_MOVE :
            begin
              { Optimized, replaced with a simple load }
              a_load_const_ref(list,size,a,ref);
            end;
          else
            begin
              internalerror(2007010101);
            end;
        end;
      end;
}

    procedure tcg68k.a_op_reg_reg(list : TAsmList; Op: TOpCG; size: TCGSize; reg1, reg2: TRegister);
      var
       hreg1,hreg2,r,r2: tregister;
      begin
        case op of
          OP_ADD :
              begin
                 if current_settings.cputype = cpu_ColdFire then
                  begin
                    { operation only allowed only a longword }
                    sign_extend(list, size, reg1);
                    sign_extend(list, size, reg2);
                    list.concat(taicpu.op_reg_reg(A_ADD,S_L,reg1, reg2));
                  end
                 else
                  begin
                    list.concat(taicpu.op_reg_reg(A_ADD,TCGSize2OpSize[size],reg1, reg2));
                  end;
              end;
          OP_AND,OP_OR,
          OP_SAR,OP_SHL,
          OP_SHR,OP_SUB,OP_XOR :
              begin
                 { load to data registers }
                 if (isaddressregister(reg1)) then
                   begin
                     hreg1 := getintregister(list,OS_INT);
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg1,hreg1));
                   end
                 else
                   hreg1 := reg1;

                 if (isaddressregister(reg2))  then
                   begin
                      hreg2:= getintregister(list,OS_INT);
                      list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg2,hreg2));
                   end
                 else
                   hreg2 := reg2;

                 if current_settings.cputype = cpu_ColdFire then
                  begin
                    { operation only allowed only a longword }
                    {!***************************************
                      in the case of shifts, the value to
                      shift by, should already be valid, so
                      no need to sign extend the value
                     !
                    }
                    if op in [OP_AND,OP_OR,OP_SUB,OP_XOR] then
                       sign_extend(list, size, hreg1);
                    sign_extend(list, size, hreg2);
                    list.concat(taicpu.op_reg_reg(topcg2tasmop[op],S_L,hreg1, hreg2));
                  end
                 else
                  begin
                    list.concat(taicpu.op_reg_reg(topcg2tasmop[op],TCGSize2OpSize[size],hreg1, hreg2));
                  end;

                 { move back result into destination register }
                 if reg2 <> hreg2 then
                   begin
                      list.concat(taicpu.op_reg_reg(A_MOVE,S_L,hreg2,reg2));
                   end;
              end;
          OP_DIV :
              begin
                 internalerror(20020816);
              end;
          OP_IDIV :
              begin
                 internalerror(20020816);
              end;
          OP_IMUL :
              begin
                 sign_extend(list, size,reg1);
                 sign_extend(list, size,reg2);
                 if current_settings.cputype = cpu_MC68000 then
                   begin
                     r:=NR_D0;
                     r2:=NR_D1;
                     cg.getcpuregister(list,NR_D0);
                     cg.getcpuregister(list,NR_D1);
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg1, r));
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg2, r2));
                     cg.a_call_name(list,'FPC_MUL_LONGINT');
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,r, reg2));
                     cg.ungetcpuregister(list,r);
                     cg.ungetcpuregister(list,r2);
                   end
                  else
                    begin
//                     writeln('doing 68020');

                     if (isaddressregister(reg1)) then
                       hreg1 := getintregister(list,OS_INT)
                     else
                       hreg1 := reg1;
                     if (isaddressregister(reg2))  then
                       hreg2:= getintregister(list,OS_INT)
                     else
                       hreg2 := reg2;

                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg1,hreg1));
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg2,hreg2));

                     list.concat(taicpu.op_reg_reg(A_MULS,S_L,reg1,reg2));

                     { move back result into destination register }

                     if reg2 <> hreg2 then
                       begin
                          list.concat(taicpu.op_reg_reg(A_MOVE,S_L,hreg2,reg2));
                       end;
                    end;
              end;
          OP_MUL :
              begin
                 sign_extend(list, size,reg1);
                 sign_extend(list, size,reg2);
                 if current_settings.cputype = cpu_MC68000 then
                   begin
                     r:=NR_D0;
                     r2:=NR_D1;
                     cg.getcpuregister(list,NR_D0);
                     cg.getcpuregister(list,NR_D1);
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg1, r));
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg2, r2));
                     cg.a_call_name(list,'FPC_MUL_LONGWORD');
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,r, reg2));
                     cg.ungetcpuregister(list,r);
                     cg.ungetcpuregister(list,r2);
                   end
                  else
                    begin
                     if (isaddressregister(reg1)) then
                      begin
                       hreg1 := cg.getintregister(list,OS_INT);
                       list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg1,hreg1));
                      end
                     else
                       hreg1 := reg1;

                     if (isaddressregister(reg2))  then
                      begin
                       hreg2:= cg.getintregister(list,OS_INT);
                       list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg2,hreg2));
                      end
                     else
                       hreg2 := reg2;

                     list.concat(taicpu.op_reg_reg(A_MULU,S_L,reg1,reg2));

                     { move back result into destination register }
                     if reg2<>hreg2 then
                       begin
                          list.concat(taicpu.op_reg_reg(A_MOVE,S_L,hreg2,reg2));
                       end;
                    end;
              end;
          OP_NEG,
          OP_NOT :
              Begin
                { if there are two operands, move the register,
                  since the operation will only be done on the result
                  register.
                }
                if reg1 <> NR_NO then
                  cg.a_load_reg_reg(current_asmdata.CurrAsmList,OS_INT,OS_INT,reg1,reg2);

                if (isaddressregister(reg2)) then
                  begin
                     hreg2 := getintregister(list,OS_INT);
                     list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg2,hreg2));
                   end
                  else
                    hreg2 := reg2;

                { coldfire only supports long version }
                if current_settings.cputype = cpu_ColdFire then
                  begin
                    sign_extend(list, size,hreg2);
                    list.concat(taicpu.op_reg(topcg2tasmop[op],S_L,hreg2));
                  end
                else
                  begin
                    list.concat(taicpu.op_reg(topcg2tasmop[op],TCGSize2OpSize[size],hreg2));
                  end;

                if reg2 <> hreg2 then
                  begin
                    list.concat(taicpu.op_reg_reg(A_MOVE,S_L,hreg2,reg2));
                  end;

              end;
        else
            internalerror(20020729);
         end;
      end;



    procedure tcg68k.a_cmp_const_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;a : aint;reg : tregister;
            l : tasmlabel);
      var
       hregister : tregister;
      begin
       if a = 0 then
         begin
           list.concat(taicpu.op_reg(A_TST,TCGSize2OpSize[size],reg));
         end
       else
         begin
           if (current_settings.cputype = cpu_ColdFire) then
             begin
               {
                 only longword comparison is supported,
                 and only on data registers.
               }
               hregister := getintregister(list,OS_INT);
               { always move to a data register }
               list.concat(taicpu.op_reg_reg(A_MOVE,S_L,reg,hregister));
               { sign/zero extend the register }
               sign_extend(list, size,hregister);
               list.concat(taicpu.op_const_reg(A_CMPI,S_L,a,hregister));
             end
           else
             begin
               list.concat(taicpu.op_const_reg(A_CMPI,TCGSize2OpSize[size],a,reg));
             end;
         end;
         { emit the actual jump to the label }
         a_jmp_cond(list,cmp_op,l);
      end;

    procedure tcg68k.a_cmp_reg_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;reg1,reg2 : tregister;l : tasmlabel);
      begin
         list.concat(taicpu.op_reg_reg(A_CMP,tcgsize2opsize[size],reg1,reg2));
         { emit the actual jump to the label }
         a_jmp_cond(list,cmp_op,l);
      end;

    procedure tcg68k.a_jmp_always(list : TAsmList;l: tasmlabel);
      var
       ai: taicpu;
      begin
         ai := Taicpu.op_sym(A_JMP,S_NO,l);
         ai.is_jmp := true;
         list.concat(ai);
      end;

    procedure tcg68k.a_jmp_flags(list : TAsmList;const f : TResFlags;l: tasmlabel);
       var
         ai : taicpu;
       begin
         ai := Taicpu.op_sym(A_BXX,S_NO,l);
         ai.SetCondition(flags_to_cond(f));
         ai.is_jmp := true;
         list.concat(ai);
       end;

    procedure tcg68k.g_flags2reg(list: TAsmList; size: TCgSize; const f: tresflags; reg: TRegister);
       var
         ai : taicpu;
         hreg : tregister;
       begin
          { move to a Dx register? }
          if (isaddressregister(reg)) then
            begin
              hreg := getintregister(list,OS_INT);
              a_load_const_reg(list,size,0,hreg);
              ai:=Taicpu.Op_reg(A_Sxx,S_B,hreg);
              ai.SetCondition(flags_to_cond(f));
              list.concat(ai);

              if (current_settings.cputype = cpu_ColdFire) then
                begin
                 { neg.b does not exist on the Coldfire
                   so we need to sign extend the value
                   before doing a neg.l
                 }
                 list.concat(taicpu.op_reg(A_EXTB,S_L,hreg));
                 list.concat(taicpu.op_reg(A_NEG,S_L,hreg));
                end
              else
                begin
                  list.concat(taicpu.op_reg(A_NEG,S_B,hreg));
                end;
             list.concat(taicpu.op_reg_reg(A_MOVE,S_L,hreg,reg));
            end
          else
          begin
            a_load_const_reg(list,size,0,reg);
            ai:=Taicpu.Op_reg(A_Sxx,S_B,reg);
            ai.SetCondition(flags_to_cond(f));
            list.concat(ai);

            if (current_settings.cputype = cpu_ColdFire) then
              begin
                 { neg.b does not exist on the Coldfire
                   so we need to sign extend the value
                   before doing a neg.l
                 }
                 list.concat(taicpu.op_reg(A_EXTB,S_L,reg));
                 list.concat(taicpu.op_reg(A_NEG,S_L,reg));
              end
            else
              begin
               list.concat(taicpu.op_reg(A_NEG,S_B,reg));
              end;
          end;
       end;



    procedure tcg68k.g_concatcopy(list : TAsmList;const source,dest : treference;len : aint);

     var
         helpsize : longint;
         i : byte;
         reg8,reg32 : tregister;
         swap : boolean;
         hregister : tregister;
         iregister : tregister;
         jregister : tregister;
         hp1 : treference;
         hp2 : treference;
         hl : tasmlabel;
         hl2: tasmlabel;
         popaddress : boolean;
         srcref,dstref : treference;

      begin
         popaddress := false;

//	 writeln('concatcopy:',len);

         { this should never occur }
         if len > 65535 then
           internalerror(0);

         hregister := getintregister(list,OS_INT);
//         if delsource then
//            reference_release(list,source);

         { from 12 bytes movs is being used }
         if {(not loadref) and} ((len<=8) or (not(cs_opt_size in current_settings.optimizerswitches) and (len<=12))) then
           begin
              srcref := source;
              dstref := dest;
              helpsize:=len div 4;
              { move a dword x times }
              for i:=1 to helpsize do
                begin
                   a_load_ref_reg(list,OS_INT,OS_INT,srcref,hregister);
                   a_load_reg_ref(list,OS_INT,OS_INT,hregister,dstref);
                   inc(srcref.offset,4);
                   inc(dstref.offset,4);
                   dec(len,4);
                end;
              { move a word }
              if len>1 then
                begin
                   a_load_ref_reg(list,OS_16,OS_16,srcref,hregister);
                   a_load_reg_ref(list,OS_16,OS_16,hregister,dstref);
                   inc(srcref.offset,2);
                   inc(dstref.offset,2);
                   dec(len,2);
                end;
              { move a single byte }
              if len>0 then
                begin
                   a_load_ref_reg(list,OS_8,OS_8,srcref,hregister);
                   a_load_reg_ref(list,OS_8,OS_8,hregister,dstref);
                end
           end
         else
           begin
              iregister:=getaddressregister(list);
              jregister:=getaddressregister(list);
              { reference for move (An)+,(An)+ }
              reference_reset(hp1);
              hp1.base := iregister;   { source register }
              hp1.direction := dir_inc;
              reference_reset(hp2);
              hp2.base := jregister;
              hp2.direction := dir_inc;
              { iregister = source }
              { jregister = destination }

{              if loadref then
                 cg.a_load_ref_reg(list,OS_INT,OS_INT,source,iregister)
              else}
                 a_loadaddr_ref_reg(list,source,iregister);

              a_loadaddr_ref_reg(list,dest,jregister);

              { double word move only on 68020+ machines }
              { because of possible alignment problems   }
              { use fast loop mode }
              if (current_settings.cputype=cpu_MC68020) then
                begin
                   helpsize := len - len mod 4;
                   len := len mod 4;
                   list.concat(taicpu.op_const_reg(A_MOVE,S_L,helpsize div 4,hregister));
                   current_asmdata.getjumplabel(hl2);
                   a_jmp_always(list,hl2);
                   current_asmdata.getjumplabel(hl);
                   a_label(list,hl);
                   list.concat(taicpu.op_ref_ref(A_MOVE,S_L,hp1,hp2));
                   a_label(list,hl2);
                   list.concat(taicpu.op_reg_sym(A_DBRA,S_L,hregister,hl));
                   if len > 1 then
                     begin
                        dec(len,2);
                        list.concat(taicpu.op_ref_ref(A_MOVE,S_W,hp1,hp2));
                     end;
                   if len = 1 then
                     list.concat(taicpu.op_ref_ref(A_MOVE,S_B,hp1,hp2));
                end
              else
                begin
                   { Fast 68010 loop mode with no possible alignment problems }
                   helpsize := len;
                   list.concat(taicpu.op_const_reg(A_MOVE,S_L,helpsize,hregister));
                   current_asmdata.getjumplabel(hl2);
                   a_jmp_always(list,hl2);
                   current_asmdata.getjumplabel(hl);
                   a_label(list,hl);
                   list.concat(taicpu.op_ref_ref(A_MOVE,S_B,hp1,hp2));
                   a_label(list,hl2);
                   list.concat(taicpu.op_reg_sym(A_DBRA,S_L,hregister,hl));
                end;

              { restore the registers that we have just used olny if they are used! }
              if jregister = NR_A1 then
                hp2.base := NR_NO;
              if iregister = NR_A0 then
                hp1.base := NR_NO;
//              reference_release(list,hp1);
//              reference_release(list,hp2);
           end;

//           if delsource then
//               tg.ungetiftemp(list,source);
    end;

    procedure tcg68k.g_overflowcheck(list: TAsmList; const l:tlocation; def:tdef);
      begin
      end;

    procedure tcg68k.g_copyvaluepara_openarray(list : TAsmList;const ref:treference;const lenloc:tlocation;elesize:aint;destreg:tregister);
      begin
      end;


    procedure tcg68k.g_proc_entry(list: TAsmList; localsize: longint; nostackframe:boolean);
      var
        r,rsp: TRegister;
        ref  : TReference;
      begin
{$ifdef DEBUG_CHARLIE}
        writeln('proc entry, localsize:',localsize);
{$endif DEBUG_CHARLIE}

        if not nostackframe then
          begin
            if (localsize<>0) then localsize:=-localsize;
            // size can't be negative
            if (localsize>0) then internalerror(2006122601);
            list.concat(taicpu.op_reg_const(A_LINK,S_W,NR_FRAME_POINTER_REG,localsize));
          end;
      end;
(*
        r:=NR_FRAME_POINTER_REG;
        rsp:=NR_STACK_POINTER_REG;
        if localsize<>0 then
           begin
             { Not to complicate the code generator too much, and since some  }
             { of the systems only support this format, the localsize cannot }
             { exceed 32K in size.                                            }
             if (localsize < low(smallint)) or (localsize > high(smallint)) then
                CGMessage(cg_e_localsize_too_big);
             list.concat(taicpu.op_reg_const(A_LINK,S_W,r,-localsize));
           end { endif localsize <> 0 }
          else
           begin
             reference_reset_base(ref,NR_STACK_POINTER_REG,0);
             ref.direction:=dir_dec;
             list.concat(taicpu.op_reg_ref(A_MOVE,S_L,r,ref));
             list.concat(taicpu.op_reg_reg(A_MOVE,S_L,rsp,r));
           end;
           *)
    //  end;


{    procedure tcg68k.g_restore_frame_pointer(list : TAsmList);
      var
        r:Tregister;
      begin
        r:=NR_FRAME_POINTER_REG;
        list.concat(taicpu.op_reg(A_UNLK,S_NO,r));
      end;
}

    procedure tcg68k.g_proc_exit(list : TAsmList; parasize: longint; nostackframe: boolean);
      var
//        r,hregister : TRegister;
        localsize: aint;
        spr : TRegister;
        fpr : TRegister;
        ref : TReference;
      begin
        if not nostackframe then
          begin
            localsize := current_procinfo.calc_stackframe_size;
{$ifdef DEBUG_CHARLIE}
            writeln('proc exit with stackframe, size:',localsize);
{$endif DEBUG_CHARLIE}
            list.concat(taicpu.op_reg(A_UNLK,S_NO,NR_FRAME_POINTER_REG));
            if (localsize<>0) then
              begin
                { only 68020+ supports RTD, so this needs another code path
                  for 68000 and Coldfire (KB) }
{$WARNING 68020+ only code generation, without fallback}
                inc(localsize,4);
                list.concat(taicpu.op_const(A_RTD,S_NO,localsize));
              end
            else
              list.concat(taicpu.op_none(A_RTS,S_NO));
          end
        else
          begin
{$ifdef DEBUG_CHARLIE}
            writeln('proc exit, no stackframe');
{$endif DEBUG_CHARLIE}
            list.concat(taicpu.op_none(A_RTS,S_NO));
          end;

//         writeln('g_proc_exit');
         { Routines with the poclearstack flag set use only a ret.
           also  routines with parasize=0     }
           (*
         if current_procinfo.procdef.proccalloption in clearstack_pocalls then
           begin
             { complex return values are removed from stack in C code PM }
             if paramanager.ret_in_param(current_procinfo.procdef.returndef,current_procinfo.procdef.proccalloption) then
               list.concat(taicpu.op_const(A_RTD,S_NO,4))
             else
               list.concat(taicpu.op_none(A_RTS,S_NO));
           end
         else if (parasize=0) then
           begin
             list.concat(taicpu.op_none(A_RTS,S_NO));
           end
         else
           begin
            { return with immediate size possible here
              signed!
              RTD is not supported on the coldfire     }
            if (current_settings.cputype=cpu_MC68020) and (parasize<$7FFF) then
                list.concat(taicpu.op_const(A_RTD,S_NO,parasize))
            { manually restore the stack }
            else
              begin
                { We must pull the PC Counter from the stack, before  }
                { restoring the stack pointer, otherwise the PC would }
                { point to nowhere!                                   }

                { save the PC counter (pop it from the stack)         }
                hregister:=NR_A3;
                cg.a_reg_alloc(list,hregister);
                reference_reset_base(ref,NR_STACK_POINTER_REG,0);
                ref.direction:=dir_inc;
                list.concat(taicpu.op_ref_reg(A_MOVE,S_L,ref,hregister));
                { can we do a quick addition ... }
                r:=NR_SP;
                if (parasize > 0) and (parasize < 9) then
                   list.concat(taicpu.op_const_reg(A_ADDQ,S_L,parasize,r))
                else { nope ... }
                   list.concat(taicpu.op_const_reg(A_ADD,S_L,parasize,r));

                { restore the PC counter (push it on the stack)       }
                reference_reset_base(ref,NR_STACK_POINTER_REG,0);
                ref.direction:=dir_dec;
                cg.a_reg_alloc(list,hregister);
                list.concat(taicpu.op_reg_ref(A_MOVE,S_L,hregister,ref));
                list.concat(taicpu.op_none(A_RTS,S_NO));
               end;
           end;
           *)
      end;


    procedure Tcg68k.g_save_standard_registers(list:TAsmList);
      var
        tosave : tcpuregisterset;
        ref : treference;
      begin
      {!!!!!
        tosave:=std_saved_registers;
        { only save the registers which are not used and must be saved }
        tosave:=tosave*(rg[R_INTREGISTER].used_in_proc+rg[R_ADDRESSREGISTER].used_in_proc);
        reference_reset_base(ref,NR_STACK_POINTER_REG,0);
        ref.direction:=dir_dec;
        if tosave<>[] then
          list.concat(taicpu.op_regset_ref(A_MOVEM,S_L,tosave,ref));
      }
      end;


    procedure Tcg68k.g_restore_standard_registers(list:TAsmList);
      var
        torestore : tcpuregisterset;
        r:Tregister;
        ref : treference;
      begin
      {!!!!!!!!
        torestore:=std_saved_registers;
        { should be intersected with used regs, no ? }
        torestore:=torestore*(rg[R_INTREGISTER].used_in_proc+rg[R_ADDRESSREGISTER].used_in_proc);
        reference_reset_base(ref,NR_STACK_POINTER_REG,0);
        ref.direction:=dir_inc;
        if torestore<>[] then
          list.concat(taicpu.op_ref_regset(A_MOVEM,S_L,ref,torestore));
      }
      end;

{
    procedure tcg68k.g_save_all_registers(list : TAsmList);
      begin
      end;

    procedure tcg68k.g_restore_all_registers(list : TAsmList;const funcretparaloc:TCGPara);
      begin
      end;
}
    procedure tcg68k.sign_extend(list: TAsmList;_oldsize : tcgsize; reg: tregister);
      begin
        case _oldsize of
         { sign extend }
         OS_S8:
              begin
                if (isaddressregister(reg)) then
                   internalerror(20020729);
                if (current_settings.cputype = cpu_MC68000) then
                  begin
                    list.concat(taicpu.op_reg(A_EXT,S_W,reg));
                    list.concat(taicpu.op_reg(A_EXT,S_L,reg));
                  end
                else
                  begin
                    list.concat(taicpu.op_reg(A_EXTB,S_L,reg));
                  end;
              end;
         OS_S16:
              begin
                if (isaddressregister(reg)) then
                   internalerror(20020729);
                list.concat(taicpu.op_reg(A_EXT,S_L,reg));
              end;
         { zero extend }
         OS_8:
              begin
                list.concat(taicpu.op_const_reg(A_AND,S_L,$FF,reg));
              end;
         OS_16:
              begin
                list.concat(taicpu.op_const_reg(A_AND,S_L,$FFFF,reg));
              end;
        end; { otherwise the size is already correct }
      end;

     procedure tcg68k.a_jmp_cond(list : TAsmList;cond : TOpCmp;l: tasmlabel);

       var
         ai : taicpu;

       begin
         if cond=OC_None then
           ai := Taicpu.Op_sym(A_JMP,S_NO,l)
         else
           begin
             ai:=Taicpu.Op_sym(A_Bxx,S_NO,l);
             ai.SetCondition(TOpCmp2AsmCond[cond]);
           end;
         ai.is_jmp:=true;
         list.concat(ai);
       end;


    procedure tcg68k.g_intf_wrapper(list: TAsmList; procdef: tprocdef; const labelname: string; ioffset: longint);
{
        procedure loadvmttor11;
        var
          href : treference;
        begin
          reference_reset_base(href,NR_R3,0);
          cg.a_load_ref_reg(list,OS_ADDR,OS_ADDR,href,NR_R11);
        end;

        procedure op_onr11methodaddr;
        var
          href : treference;
        begin
          if (procdef.extnumber=$ffff) then
            Internalerror(200006139);
          { call/jmp  vmtoffs(%eax) ; method offs }
          reference_reset_base(href,NR_R11,procdef._class.vmtmethodoffset(procdef.extnumber));
          if not((longint(href.offset) >= low(smallint)) and
                 (longint(href.offset) <= high(smallint))) then
            begin
              list.concat(taicpu.op_reg_reg_const(A_ADDIS,NR_R11,NR_R11,
                smallint((href.offset shr 16)+ord(smallint(href.offset and $ffff) < 0))));
              href.offset := smallint(href.offset and $ffff);
            end;
          list.concat(taicpu.op_reg_ref(A_LWZ,NR_R11,href));
          list.concat(taicpu.op_reg(A_MTCTR,NR_R11));
          list.concat(taicpu.op_none(A_BCTR));
        end;
}
      var
        make_global : boolean;
      begin
        if not(procdef.proctypeoption in [potype_function,potype_procedure]) then
          Internalerror(200006137);
        if not assigned(procdef._class) or
           (procdef.procoptions*[po_classmethod, po_staticmethod,
             po_methodpointer, po_interrupt, po_iocheck]<>[]) then
          Internalerror(200006138);
        if procdef.owner.symtabletype<>ObjectSymtable then
          Internalerror(200109191);

        make_global:=false;
        if (not current_module.is_unit) or
           create_smartlink or
           (procdef.owner.defowner.owner.symtabletype=globalsymtable) then
          make_global:=true;

        if make_global then
          List.concat(Tai_symbol.Createname_global(labelname,AT_FUNCTION,0))
        else
          List.concat(Tai_symbol.Createname(labelname,AT_FUNCTION,0));

        { set param1 interface to self  }
//        g_adjust_self_value(list,procdef,ioffset);

        { case 4 }
        if po_virtualmethod in procdef.procoptions then
          begin
//            loadvmttor11;
//            op_onr11methodaddr;
          end
        { case 0 }
        else
//          list.concat(taicpu.op_sym(A_B,current_asmdata.RefAsmSymbol(procdef.mangledname)));

        List.concat(Tai_symbol_end.Createname(labelname));
      end;


{****************************************************************************}
{                               TCG64F68K                                    }
{****************************************************************************}
 procedure tcg64f68k.a_op64_reg_reg(list : TAsmList;op:TOpCG;size: tcgsize; regsrc,regdst : tregister64);
  var
   hreg1, hreg2 : tregister;
   opcode : tasmop;
  begin
//    writeln('a_op64_reg_reg');
    opcode := topcg2tasmop[op];
    case op of
      OP_ADD :
         begin
            { if one of these three registers is an address
              register, we'll really get into problems!
            }
            if isaddressregister(regdst.reglo) or
               isaddressregister(regdst.reghi) or
               isaddressregister(regsrc.reghi) then
                 internalerror(20020817);
            list.concat(taicpu.op_reg_reg(A_ADD,S_L,regsrc.reglo,regdst.reglo));
            list.concat(taicpu.op_reg_reg(A_ADDX,S_L,regsrc.reghi,regdst.reghi));
         end;
      OP_AND,OP_OR :
          begin
            { at least one of the registers must be a data register }
            if (isaddressregister(regdst.reglo) and
                isaddressregister(regsrc.reglo)) or
               (isaddressregister(regsrc.reghi) and
                isaddressregister(regdst.reghi))
               then
                 internalerror(20020817);
            cg.a_op_reg_reg(list,op,OS_32,regsrc.reglo,regdst.reglo);
            cg.a_op_reg_reg(list,op,OS_32,regsrc.reghi,regdst.reghi);
          end;
      { this is handled in 1st pass for 32-bit cpu's (helper call) }
      OP_IDIV,OP_DIV,
      OP_IMUL,OP_MUL: internalerror(2002081701);
      { this is also handled in 1st pass for 32-bit cpu's (helper call) }
      OP_SAR,OP_SHL,OP_SHR: internalerror(2002081702);
      OP_SUB:
         begin
            { if one of these three registers is an address
              register, we'll really get into problems!
            }
            if isaddressregister(regdst.reglo) or
               isaddressregister(regdst.reghi) or
               isaddressregister(regsrc.reghi) then
                 internalerror(20020817);
            list.concat(taicpu.op_reg_reg(A_SUB,S_L,regsrc.reglo,regdst.reglo));
            list.concat(taicpu.op_reg_reg(A_SUBX,S_L,regsrc.reghi,regdst.reghi));
         end;
      OP_XOR:
        begin
            if isaddressregister(regdst.reglo) or
               isaddressregister(regsrc.reglo) or
               isaddressregister(regsrc.reghi) or
               isaddressregister(regdst.reghi) then
                 internalerror(20020817);
            list.concat(taicpu.op_reg_reg(A_EOR,S_L,regsrc.reglo,regdst.reglo));
            list.concat(taicpu.op_reg_reg(A_EOR,S_L,regsrc.reghi,regdst.reghi));
        end;
    end; { end case }
  end;


 procedure tcg64f68k.a_op64_const_reg(list : TAsmList;op:TOpCG;size: tcgsize; value : int64;regdst : tregister64);
  var
   lowvalue : cardinal;
   highvalue : cardinal;
   hreg : tregister;
  begin
//    writeln('a_op64_const_reg');
    { is it optimized out ? }
//    if cg.optimize64_op_const_reg(list,op,value,reg) then
//       exit;

    lowvalue := cardinal(value);
    highvalue:= value shr 32;

   { the destination registers must be data registers }
   if  isaddressregister(regdst.reglo) or
       isaddressregister(regdst.reghi) then
         internalerror(20020817);
   case op of
      OP_ADD :
         begin
           hreg:=cg.getintregister(list,OS_INT);
           list.concat(taicpu.op_const_reg(A_MOVE,S_L,highvalue,hreg));
           list.concat(taicpu.op_const_reg(A_ADD,S_L,lowvalue,regdst.reglo));
           list.concat(taicpu.op_reg_reg(A_ADDX,S_L,hreg,regdst.reglo));
         end;
      OP_AND :
          begin
            list.concat(taicpu.op_const_reg(A_AND,S_L,lowvalue,regdst.reglo));
            list.concat(taicpu.op_const_reg(A_AND,S_L,highvalue,regdst.reglo));
          end;
      OP_OR :
          begin
            list.concat(taicpu.op_const_reg(A_OR,S_L,lowvalue,regdst.reglo));
            list.concat(taicpu.op_const_reg(A_OR,S_L,highvalue,regdst.reglo));
          end;
      { this is handled in 1st pass for 32-bit cpus (helper call) }
      OP_IDIV,OP_DIV,
      OP_IMUL,OP_MUL: internalerror(2002081701);
      { this is also handled in 1st pass for 32-bit cpus (helper call) }
      OP_SAR,OP_SHL,OP_SHR: internalerror(2002081702);
      OP_SUB:
         begin
           hreg:=cg.getintregister(list,OS_INT);
           list.concat(taicpu.op_const_reg(A_MOVE,S_L,highvalue,hreg));
           list.concat(taicpu.op_const_reg(A_SUB,S_L,lowvalue,regdst.reglo));
           list.concat(taicpu.op_reg_reg(A_SUBX,S_L,hreg,regdst.reglo));
         end;
      OP_XOR:
        begin
            list.concat(taicpu.op_const_reg(A_EOR,S_L,lowvalue,regdst.reglo));
            list.concat(taicpu.op_const_reg(A_EOR,S_L,highvalue,regdst.reglo));
        end;
    end; { end case }
  end;

begin
  cg := tcg68k.create;
  cg64 :=tcg64f68k.create;
end.