{

    Copyright (c) 2008 by Florian Klaempfl
    Member of the Free Pascal development team

    This unit implements the code generator for the AVR

    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 cgcpu;

{$i fpcdefs.inc}

  interface

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


    type

      { tcgavr }

      tcgavr = class(tcg)
        { true, if the next arithmetic operation should modify the flags }
        cgsetflags : boolean;
        procedure init_register_allocators;override;
        procedure done_register_allocators;override;

        function getintregister(list:TAsmList;size:Tcgsize):Tregister;override;
        function getaddressregister(list:TAsmList):Tregister;override;

        procedure prepareref(list: TAsmList; var r: treference);
        procedure incabsref(list: TAsmList;var r: treference);

        procedure a_load_const_cgpara(list : TAsmList;size : tcgsize;a : aint;const paraloc : TCGPara);override;
        procedure a_load_ref_cgpara(list : TAsmList;size : tcgsize;const r : treference;const paraloc : TCGPara);override;
        procedure a_loadaddr_ref_cgpara(list : TAsmList;const r : treference;const paraloc : TCGPara);override;

        procedure a_call_name(list : TAsmList;const s : string; weak: boolean);override;
        procedure a_call_reg(list : TAsmList;reg: tregister);override;
        procedure a_call_ref(list : TAsmList;ref: treference);override;

        procedure a_op_const_reg(list : TAsmList; Op: TOpCG; size: TCGSize; a: aint; reg: TRegister); override;
        procedure a_op_reg_reg(list : TAsmList; Op: TOpCG; size: TCGSize; src, dst: TRegister); override;

        procedure a_op_const_reg_reg(list: TAsmList; op: TOpCg;
          size: tcgsize; a: aint; src, dst: tregister); override;
        procedure a_op_reg_reg_reg(list: TAsmList; op: TOpCg;
          size: tcgsize; src1, src2, dst: tregister); override;
        procedure a_op_const_reg_reg_checkoverflow(list: TAsmList; op: TOpCg; size: tcgsize; a: aint; src, dst: tregister;setflags : boolean;var ovloc : tlocation);override;
        procedure a_op_reg_reg_reg_checkoverflow(list: TAsmList; op: TOpCg; size: tcgsize; src1, src2, dst: tregister;setflags : boolean;var ovloc : tlocation);override;

        { move instructions }
        procedure a_load_const_reg(list : TAsmList; size: tcgsize; a : aint;reg : tregister);override;
        procedure a_load_reg_ref(list : TAsmList; fromsize, tosize: tcgsize; reg : tregister;const ref : treference);override;
        procedure a_load_ref_reg(list : TAsmList; fromsize, tosize : tcgsize;const Ref : treference;reg : tregister);override;
        procedure a_load_reg_reg(list : TAsmList; fromsize, tosize : tcgsize;reg1,reg2 : tregister);override;

        {  comparison operations }
        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_name(list : TAsmList;const s : string); 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_proc_entry(list : TAsmList;localsize : longint;nostackframe:boolean);override;
        procedure g_proc_exit(list : TAsmList;parasize : longint;nostackframe:boolean); override;

        procedure a_loadaddr_ref_reg(list : TAsmList;const ref : treference;r : tregister);override;

        procedure g_concatcopy(list : TAsmList;const source,dest : treference;len : aint);override;
        procedure g_concatcopy_unaligned(list : TAsmList;const source,dest : treference;len : aint);override;
        procedure g_concatcopy_move(list : TAsmList;const source,dest : treference;len : aint);
        procedure g_concatcopy_internal(list : TAsmList;const source,dest : treference;len : aint;aligned : boolean);

        procedure g_overflowcheck(list: TAsmList; const l: tlocation; def: tdef); override;
        procedure g_overflowCheck_loc(List:TAsmList;const Loc:TLocation;def:TDef;ovloc : tlocation);override;

//        procedure g_save_registers(list : TAsmList);override;
//        procedure g_restore_registers(list : TAsmList);override;

        procedure a_jmp_cond(list : TAsmList;cond : TOpCmp;l: tasmlabel);
        procedure fixref(list : TAsmList;var ref : treference);
        function normalize_ref(list:TAsmList;op: tasmop;reg:tregister;ref: treference):treference;

        procedure g_intf_wrapper(list: TAsmList; procdef: tprocdef; const labelname: string; ioffset: longint);override;
        procedure emit_mov(list: TAsmList;reg2: tregister; reg1: tregister);

      end;

      tcg64favr = 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;reg : tregister64);override;
        procedure a_op64_const_reg_reg(list: TAsmList;op:TOpCG;size : tcgsize;value : int64;regsrc,regdst : tregister64);override;
        procedure a_op64_reg_reg_reg(list: TAsmList;op:TOpCG;size : tcgsize;regsrc1,regsrc2,regdst : tregister64);override;
        procedure a_op64_const_reg_reg_checkoverflow(list: TAsmList;op:TOpCG;size : tcgsize;value : int64;regsrc,regdst : tregister64;setflags : boolean;var ovloc : tlocation);override;
        procedure a_op64_reg_reg_reg_checkoverflow(list: TAsmList;op:TOpCG;size : tcgsize;regsrc1,regsrc2,regdst : tregister64;setflags : boolean;var ovloc : tlocation);override;
      end;
      
    procedure create_codegen;

    const
      OpCmp2AsmCond : Array[topcmp] of TAsmCond = (C_NONE,C_EQ,C_GT,
                           C_LT,C_GE,C_LE,C_NE,C_LS,C_CC,C_CS,C_HI);

  implementation


    uses
       globals,verbose,systems,cutils,
       fmodule,
       symconst,symsym,
       tgobj,
       procinfo,cpupi,
       paramgr;


    procedure tcgavr.init_register_allocators;
      begin
        inherited init_register_allocators;
        { currently, we save R14 always, so we can use it }
        rg[R_INTREGISTER]:=trgintcpu.create(R_INTREGISTER,R_SUBWHOLE,
            [RS_R0,RS_R1,RS_R2,RS_R3,RS_R4,RS_R5,RS_R6,RS_R7,RS_R8,
             RS_R9,RS_R10,RS_R12,RS_R14],first_int_imreg,[]);
      end;


    procedure tcgavr.done_register_allocators;
      begin
        rg[R_INTREGISTER].free;
        inherited done_register_allocators;
      end;


    function tcgavr.getintregister(list: TAsmList; size: Tcgsize): Tregister;
      var
        tmp1,tmp2,tmp3 : TRegister;
      begin
        case size of
          OS_8,OS_S8:
            Result:=inherited getintregister(list, size);
          OS_16,OS_S16:
            begin
              Result:=inherited getintregister(list, OS_8);
              { ensure that the high register can be retrieved by
                GetNextReg
              }
              if inherited getintregister(list, OS_8)<>GetNextReg(Result) then
                internalerror(2011021331);
            end;
          OS_32,OS_S32:
            begin
              Result:=inherited getintregister(list, OS_8);
              tmp1:=inherited getintregister(list, OS_8);
              { ensure that the high register can be retrieved by
                GetNextReg
              }
              if tmp1<>GetNextReg(Result) then
                internalerror(2011021332);
              tmp2:=inherited getintregister(list, OS_8);
              { ensure that the upper register can be retrieved by
                GetNextReg
              }
              if tmp2<>GetNextReg(tmp1) then
                internalerror(2011021333);
              tmp3:=inherited getintregister(list, OS_8);
              { ensure that the upper register can be retrieved by
                GetNextReg
              }
              if tmp3<>GetNextReg(tmp2) then
                internalerror(2011021334);
            end;
          else
            internalerror(2011021330);
        end;
      end;


    function tcgavr.getaddressregister(list: TAsmList): Tregister;
      var
        supreg,i : tsuperregister;
      begin
        Result:=getintregister(list,OS_16);
        supreg:=getsupreg(Result);
        for i:=RS_R0 to RS_R25 do
          rg[R_INTREGISTER].add_edge(supreg,i);
        rg[R_INTREGISTER].add_edge(supreg,RS_R27);
        rg[R_INTREGISTER].add_edge(supreg,RS_R29);
        rg[R_INTREGISTER].add_edge(supreg,RS_R31);
      end;


    procedure tcgavr.a_load_const_cgpara(list : TAsmList;size : tcgsize;a : aint;const paraloc : TCGPara);
      var
        ref: treference;
      begin
        paraloc.check_simple_location;
        paramanager.allocparaloc(list,paraloc.location);
        case paraloc.location^.loc of
          LOC_REGISTER,LOC_CREGISTER:
            a_load_const_reg(list,size,a,paraloc.location^.register);
          LOC_REFERENCE:
            begin
               reference_reset(ref,paraloc.alignment);
               ref.base:=paraloc.location^.reference.index;
               ref.offset:=paraloc.location^.reference.offset;
               a_load_const_ref(list,size,a,ref);
            end;
          else
            internalerror(2002081101);
        end;
      end;


    procedure tcgavr.a_load_ref_cgpara(list : TAsmList;size : tcgsize;const r : treference;const paraloc : TCGPara);
      var
        tmpref, ref: treference;
        location: pcgparalocation;
        sizeleft: aint;
      begin
        location := paraloc.location;
        tmpref := r;
        sizeleft := paraloc.intsize;
        while assigned(location) do
          begin
            paramanager.allocparaloc(list,location);
            case location^.loc of
              LOC_REGISTER,LOC_CREGISTER:
                a_load_ref_reg(list,location^.size,location^.size,tmpref,location^.register);
              LOC_REFERENCE:
                begin
                  reference_reset_base(ref,location^.reference.index,location^.reference.offset,paraloc.alignment);
                  { doubles in softemu mode have a strange order of registers and references }
                  if location^.size=OS_32 then
                    g_concatcopy(list,tmpref,ref,4)
                  else
                    begin
                      g_concatcopy(list,tmpref,ref,sizeleft);
                      if assigned(location^.next) then
                        internalerror(2005010710);
                    end;
                end;
              LOC_VOID:
                begin
                  // nothing to do
                end;
              else
                internalerror(2002081103);
            end;
            inc(tmpref.offset,tcgsize2size[location^.size]);
            dec(sizeleft,tcgsize2size[location^.size]);
            location := location^.next;
          end;
      end;


    procedure tcgavr.a_loadaddr_ref_cgpara(list : TAsmList;const r : treference;const paraloc : TCGPara);
      var
        ref: treference;
        tmpreg: tregister;
      begin
        paraloc.check_simple_location;
        paramanager.allocparaloc(list,paraloc.location);
        case paraloc.location^.loc of
          LOC_REGISTER,LOC_CREGISTER:
            a_loadaddr_ref_reg(list,r,paraloc.location^.register);
          LOC_REFERENCE:
            begin
              reference_reset(ref,paraloc.alignment);
              ref.base := paraloc.location^.reference.index;
              ref.offset := paraloc.location^.reference.offset;
              tmpreg := getintregister(list,OS_ADDR);
              a_loadaddr_ref_reg(list,r,tmpreg);
              a_load_reg_ref(list,OS_ADDR,OS_ADDR,tmpreg,ref);
            end;
          else
            internalerror(2002080701);
        end;
      end;


    procedure tcgavr.a_call_name(list : TAsmList;const s : string; weak: boolean);
      begin
        list.concat(taicpu.op_sym(A_RCALL,current_asmdata.RefAsmSymbol(s)));
{
        the compiler does not properly set this flag anymore in pass 1, and
        for now we only need it after pass 2 (I hope) (JM)
          if not(pi_do_call in current_procinfo.flags) then
            internalerror(2003060703);
}
        include(current_procinfo.flags,pi_do_call);
      end;


    procedure tcgavr.a_call_reg(list : TAsmList;reg: tregister);
      begin
        a_reg_alloc(list,NR_ZLO);
        a_reg_alloc(list,NR_ZHI);
        list.concat(taicpu.op_reg_reg(A_MOV,NR_ZLO,reg));
        list.concat(taicpu.op_reg_reg(A_MOV,NR_ZHI,GetHigh(reg)));
        list.concat(taicpu.op_none(A_ICALL));
        a_reg_dealloc(list,NR_ZLO);
        a_reg_dealloc(list,NR_ZHI);

        include(current_procinfo.flags,pi_do_call);
      end;


    procedure tcgavr.a_call_ref(list : TAsmList;ref: treference);
      begin
        a_reg_alloc(list,NR_ZLO);
        a_reg_alloc(list,NR_ZHI);
        a_load_ref_reg(list,OS_ADDR,OS_ADDR,ref,NR_ZLO);
        list.concat(taicpu.op_none(A_ICALL));
        a_reg_dealloc(list,NR_ZLO);
        a_reg_dealloc(list,NR_ZHI);

        include(current_procinfo.flags,pi_do_call);
      end;


     procedure tcgavr.a_op_const_reg(list : TAsmList; Op: TOpCG; size: TCGSize; a: aint; reg: TRegister);
       begin
          a_op_const_reg_reg(list,op,size,a,reg,reg);
       end;


     procedure tcgavr.a_op_reg_reg(list : TAsmList; Op: TOpCG; size: TCGSize; src, dst: TRegister);
       var
         tmpreg: tregister;
      begin
         internalerror(2011021301);
         case op of
           OP_NEG:
             if src<>dst then
               a_load_reg_reg(list,size,size,src,dst);
             list.concat(taicpu.op_reg(A_NEG,dst));
             if size in [OS_S16,OS_16,OS_S32,OS_32] then
               begin
                 tmpreg:=GetNextReg(dst);
                 list.concat(taicpu.op_reg(A_NOT,S_L,));
                 list.concat(taicpu.op_reg(A_NEG,S_L,regdst.reglo));
                 list.concat(taicpu.op_const_reg(A_SBB,S_L,-1,regdst.reghi));
               end;
           OP_NOT:
             begin
               for i:=1 to cgsize2size[size] do
                 begin
                   if src<>dst then
                     a_load_reg_reg(list,OS_8,OS_8,src,dst);
                   list.concat(taicpu.op_reg(A_NOT,S_L,dst));
                   src:=GetNextReg(src);
                   dst:=GetNextReg(dst);
                 end;
             end
           else
             a_op_reg_reg_reg(list,op,size,src,dst,dst);
         end;
       end;


    procedure tcgavr.a_op_const_reg_reg(list: TAsmList; op: TOpCg;
      size: tcgsize; a: aint; src, dst: tregister);
      var
        ovloc : tlocation;
      begin
        a_op_const_reg_reg_checkoverflow(list,op,size,a,src,dst,false,ovloc);
      end;


    procedure tcgavr.a_op_reg_reg_reg(list: TAsmList; op: TOpCg;
      size: tcgsize; src1, src2, dst: tregister);
      var
        ovloc : tlocation;
      begin
        a_op_reg_reg_reg_checkoverflow(list,op,size,src1,src2,dst,false,ovloc);
      end;


    procedure tcgavr.a_op_const_reg_reg_checkoverflow(list: TAsmList; op: TOpCg; size: tcgsize; a: aint; src, dst: tregister;setflags : boolean;var ovloc : tlocation);
      begin
        internalerror(2011021302);
      end;


    procedure tcgavr.a_op_reg_reg_reg_checkoverflow(list: TAsmList; op: TOpCg; size: tcgsize; src1, src2, dst: tregister;setflags : boolean;var ovloc : tlocation);
      var
        so : tshifterop;
        tmpreg,overflowreg : tregister;
        asmop : tasmop;
      begin
        internalerror(2011021303);
        ovloc.loc:=LOC_VOID;
        case op of
          OP_NEG,OP_NOT,
          OP_DIV,OP_IDIV:
            internalerror(200308281);
          OP_SHL:
            begin
            end;
          OP_SHR:
            begin
            end;
          OP_SAR:
            begin
            end;
          OP_IMUL,
          OP_MUL:
            begin
            end;
        end;
      end;


     procedure tcgavr.a_load_const_reg(list : TAsmList; size: tcgsize; a : aint;reg : tregister);
       begin
          if not(size in [OS_8,OS_S8,OS_16,OS_S16,OS_32,OS_S32]) then
            internalerror(2002090902);
       end;


    function tcgavr.normalize_ref(list:TAsmList;op: tasmop;reg:tregister;ref: treference):treference;
      var
        tmpreg : tregister;
        tmpref : treference;
        l : tasmlabel;
      begin
        tmpreg:=NR_NO;

        Result:=ref;

         if ref.addressmode<>AM_UNCHANGED then
           internalerror(2011021701);

        { Be sure to have a base register }
        if (ref.base=NR_NO) then
          begin
            { only symbol+offset? }
            if ref.index=NR_NO then
              exit;
            ref.base:=ref.index;
            ref.index:=NR_NO;
          end;
        if assigned(ref.symbol) or (ref.offset<>0) then
          begin
            tmpreg:=getaddressregister(list);
            reference_reset(tmpref,0);
            tmpref.symbol:=ref.symbol;
            tmpref.offset:=lo(word(ref.offset));
            tmpref.refaddr:=addr_lo8;
            list.concat(taicpu.op_reg_reg(A_LDI,tmpreg,tmpref);
            tmpref.offset:=hi(word(ref.offset));
            tmpref.refaddr:=addr_hi8;
            list.concat(taicpu.op_reg_reg(A_LDI,GetNextReg(tmpreg),tmpref);
            if (ref.base<>NR_NO) then
              begin
                list.concat(taicpu.op_reg_reg(A_ADD,tmpreg,ref.base);
                list.concat(taicpu.op_reg_reg(A_ADC,GetNextReg(tmpreg),GetNextReg(ref.base));
              end;
            if (ref.index<>NR_NO) then
              begin
                list.concat(taicpu.op_reg_reg(A_ADD,tmpreg,ref.base);
                list.concat(taicpu.op_reg_reg(A_ADC,GetNextReg(tmpreg),GetNextReg(ref.base));
              end;
            ref.base:=tmpreg;
            ref.index:=NR_NO;
          end
        else if (ref.base<>NR_NO) and (ref.index<>NR_NO) then
          begin
            tmpreg:=getaddressregister(list);
            list.concat(taicpu.op_reg_reg(A_MOVW,tmpreg,ref.index);
            list.concat(taicpu.op_reg_reg(A_ADD,tmpreg,ref.base);
            list.concat(taicpu.op_reg_reg(A_ADC,GetNextReg(tmpreg),GetNextReg(ref.base));
            ref.base:=tmpreg;
            ref.index:=NR_NO;
          end;
        Result:=ref;
      end;


     procedure tcgavr.a_load_reg_ref(list : TAsmList; fromsize, tosize: tcgsize; reg : tregister;const ref : treference);
       begin
         internalerror(2011021305);
       end;


     procedure tcgavr.prepareref(list : TAsmList; var r : treference);
       begin

       end;

     procedure tcgavr.incref(list: TAsmList; var r: treference);
       begin

       end;

     procedure tcgavr.a_load_ref_reg(list : TAsmList; fromsize, tosize : tcgsize;const Ref : treference;reg : tregister);
       var
         href : treference;
         conv_done: boolean;
         tmpreg : tregister;
       begin
         href:=Ref;
         prepareref(list,href);
         if (tcgsize2size[fromsize]>32) or (tcgsize2size[tosize]>32) or (fromsize=OS_NO) or (tosize=OS_NO) then
           internalerror(2011021307);

         conv_done:=false;
         if tosize<>fromsize then
           begin
             conv_done:=true;
             if tcgsize2size[tosize]<=tcgsize2size[fromsize] then
               fromsize:=tosize;
             case fromsize of
               OS_8:
                 begin
                   list.concat(taicpu.op_reg_ref(A_LD,reg,href));
                   for i:=2 to tcgsize2size[tosize] do
                     begin
                       reg:=GetNextReg(reg);
                       list.concat(taicpu.op_reg(A_CLR,reg));
                     end;
                 end;
               OS_S8:
                 begin
                   { dest is always at least 16 bit at this point }
                   list.concat(taicpu.op_reg_ref(A_LD,reg,href));
                   tmpreg:=reg;

                   reg2:=GetNextReg(reg);
                   list.concat(taicpu.op_reg(A_CLR,reg));
                   list.concat(taicpu.op_reg_const(A_SBIC,tmpreg,7));
                   list.concat(taicpu.op_reg(A_COM,reg));
                   tmpreg:=register;
                   for i:=3 to tcgsize2size[tosize] do
                     begin
                       reg:=GetNextReg(reg);
                       emit_mov(list,reg2,tmpreg);
                     end;
                 end;
               OS_16:
                 begin
                   incref(href);
                   list.concat(taicpu.op_reg_ref(A_LD,reg,href));

                   reg:=GetNextReg(reg);
                   list.concat(taicpu.op_reg_ref(A_LD,reg,href));

                   for i:=3 to tcgsize2size[tosize] do
                     begin
                       reg:=GetNextReg(reg);
                       list.concat(taicpu.op_reg(A_CLR,reg));
                     end;
                 end;
               OS_S16:
                 begin
                   { dest is always at least 32 bit at this point }
                   emit_mov(list,reg2,reg1);

                   reg1:=GetNextReg(reg1);
                   reg2:=GetNextReg(reg2);
                   emit_mov(list,reg2,reg1);

                   reg2:=GetNextReg(reg2);
                   list.concat(taicpu.op_reg(A_CLR,reg2));
                   list.concat(taicpu.op_reg_const(A_SBIC,reg1,7));
                   list.concat(taicpu.op_reg(A_COM,reg2));
                   tmpreg:=register;
                   for i:=4 to tcgsize2size[tosize] do
                     begin
                       reg2:=GetNextReg(reg2);
                       emit_mov(list,reg2,tmpreg);
                     end;
                 end;
               else
                 conv_done:=false;
             end;
           end;
         if not conv_done and (reg1<>reg2) then
           begin
             for i:=1 to tcgsize2size[fromsize] do
               begin
                 emit_mov(list,reg2,reg1);
                 reg1:=GetNextReg(reg1);
                 reg2:=GetNextReg(reg2);
               end;
           end;
       end;


     procedure tcgavr.a_load_reg_reg(list : TAsmList; fromsize, tosize : tcgsize;reg1,reg2 : tregister);
       var
         conv_done: boolean;
         tmpreg : tregister;
       begin
         if (tcgsize2size[fromsize]>32) or (tcgsize2size[tosize]>32) or (fromsize=OS_NO) or (tosize=OS_NO) then
           internalerror(2011021310);

         conv_done:=false;
         if tosize<>fromsize then
           begin
             conv_done:=true;
             if tcgsize2size[tosize]<=tcgsize2size[fromsize] then
               fromsize:=tosize;
             case fromsize of
               OS_8:
                 begin
                   emit_mov(list,reg2,reg1);
                   for i:=2 to tcgsize2size[tosize] do
                     begin
                       reg2:=GetNextReg(reg2);
                       list.concat(taicpu.op_reg(A_CLR,reg2));
                     end;
                 end;
               OS_S8:
                 begin
                   { dest is always at least 16 bit at this point }
                   emit_mov(list,reg2,reg1);

                   reg2:=GetNextReg(reg2);
                   list.concat(taicpu.op_reg(A_CLR,reg2));
                   list.concat(taicpu.op_reg_const(A_SBIC,reg1,7));
                   list.concat(taicpu.op_reg(A_COM,reg2));
                   tmpreg:=register;
                   for i:=3 to tcgsize2size[tosize] do
                     begin
                       reg2:=GetNextReg(reg2);
                       emit_mov(list,reg2,tmpreg);
                     end;
                 end;
               OS_16:
                 begin
                   emit_mov(list,reg2,reg1);

                   reg1:=GetNextReg(reg1);
                   reg2:=GetNextReg(reg2);
                   emit_mov(list,reg2,reg1);

                   for i:=3 to tcgsize2size[tosize] do
                     begin
                       reg2:=GetNextReg(reg2);
                       list.concat(taicpu.op_reg(A_CLR,reg2));
                     end;
                 end;
               OS_S16:
                 begin
                   { dest is always at least 32 bit at this point }
                   emit_mov(list,reg2,reg1);

                   reg1:=GetNextReg(reg1);
                   reg2:=GetNextReg(reg2);
                   emit_mov(list,reg2,reg1);

                   reg2:=GetNextReg(reg2);
                   list.concat(taicpu.op_reg(A_CLR,reg2));
                   list.concat(taicpu.op_reg_const(A_SBIC,reg1,7));
                   list.concat(taicpu.op_reg(A_COM,reg2));
                   tmpreg:=register;
                   for i:=4 to tcgsize2size[tosize] do
                     begin
                       reg2:=GetNextReg(reg2);
                       emit_mov(list,reg2,tmpreg);
                     end;
                 end;
               else
                 conv_done:=false;
             end;
           end;
         if not conv_done and (reg1<>reg2) then
           begin
             for i:=1 to tcgsize2size[fromsize] do
               begin
                 emit_mov(list,reg2,reg1);
                 reg1:=GetNextReg(reg1);
                 reg2:=GetNextReg(reg2);
               end;
           end;
       end;


    {  comparison operations }
    procedure tcgavr.a_cmp_const_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;a : aint;reg : tregister;
      l : tasmlabel);
      begin
        internalerror(2011021311);
      end;


    procedure tcgavr.a_cmp_reg_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;reg1,reg2 : tregister;l : tasmlabel);
      begin
        internalerror(2011021312);
      end;


    procedure tcgavr.a_jmp_name(list : TAsmList;const s : string);
      begin
        internalerror(2011021313);
      end;


    procedure tcgavr.a_jmp_always(list : TAsmList;l: tasmlabel);
      begin
        internalerror(2011021314);
      end;


    procedure tcgavr.a_jmp_flags(list : TAsmList;const f : TResFlags;l: tasmlabel);
      begin
        internalerror(2011021315);
      end;


    procedure tcgavr.g_flags2reg(list: TAsmList; size: TCgSize; const f: TResFlags; reg: TRegister);
      begin
        internalerror(2011021316);
      end;


    procedure tcgavr.g_proc_entry(list : TAsmList;localsize : longint;nostackframe:boolean);
{
      var
         ref : treference;
         shift : byte;
         firstfloatreg,lastfloatreg,
         r : byte;
         regs : tcpuregisterset;
}
      begin
        internalerror(2011021317);
{
        LocalSize:=align(LocalSize,4);
        if not(nostackframe) then
          begin
            firstfloatreg:=RS_NO;
            { save floating point registers? }
            for r:=RS_F0 to RS_F7 do
              if r in rg[R_FPUREGISTER].used_in_proc-paramanager.get_volatile_registers_fpu(pocall_stdcall) then
                begin
                  if firstfloatreg=RS_NO then
                    firstfloatreg:=r;
                  lastfloatreg:=r;
                end;
            a_reg_alloc(list,NR_STACK_POINTER_REG);
            if current_procinfo.framepointer<>NR_STACK_POINTER_REG then
              begin
                a_reg_alloc(list,NR_FRAME_POINTER_REG);
                a_reg_alloc(list,NR_R12);

                list.concat(taicpu.op_reg_reg(A_MOV,NR_R12,NR_STACK_POINTER_REG));
              end;
            { save int registers }
            reference_reset(ref);
            ref.index:=NR_STACK_POINTER_REG;
            ref.addressmode:=AM_PREINDEXED;
            regs:=rg[R_INTREGISTER].used_in_proc-paramanager.get_volatile_registers_int(pocall_stdcall);
            if current_procinfo.framepointer<>NR_STACK_POINTER_REG then
              regs:=regs+[RS_R11,RS_R12,RS_R14,RS_R15]
            else
              if (regs<>[]) or (pi_do_call in current_procinfo.flags) then
                include(regs,RS_R14);
            if regs<>[] then
              list.concat(setoppostfix(taicpu.op_ref_regset(A_STM,ref,regs),PF_FD));

            if current_procinfo.framepointer<>NR_STACK_POINTER_REG then
              list.concat(taicpu.op_reg_reg_const(A_SUB,NR_FRAME_POINTER_REG,NR_R12,4));

            { allocate necessary stack size
              not necessary according to Yury Sidorov

            { don't use a_op_const_reg_reg here because we don't allow register allocations
              in the entry/exit code }
           if (target_info.system in [system_arm_wince]) and
              (localsize>=winstackpagesize) then
             begin
               if localsize div winstackpagesize<=5 then
                 begin
                    if is_shifter_const(localsize,shift) then
                      list.concat(Taicpu.op_reg_reg_const(A_SUB,NR_STACK_POINTER_REG,NR_STACK_POINTER_REG,localsize))
                    else
                      begin
                        a_load_const_reg(list,OS_ADDR,localsize,NR_R12);
                        list.concat(taicpu.op_reg_reg_reg(A_SUB,NR_STACK_POINTER_REG,NR_STACK_POINTER_REG,NR_R12));
                      end;

                    for i:=1 to localsize div winstackpagesize do
                      begin
                        if localsize-i*winstackpagesize<4096 then
                          reference_reset_base(href,NR_STACK_POINTER_REG,-(localsize-i*winstackpagesize))
                        else
                          begin
                            a_load_const_reg(list,OS_ADDR,-(localsize-i*winstackpagesize),NR_R12);
                            reference_reset_base(href,NR_STACK_POINTER_REG,0);
                            href.index:=NR_R12;
                          end;
                        { the data stored doesn't matter }
                        list.concat(Taicpu.op_reg_ref(A_STR,NR_R0,href));
                      end;
                    a_reg_dealloc(list,NR_R12);
                    reference_reset_base(href,NR_STACK_POINTER_REG,0);
                    { the data stored doesn't matter }
                    list.concat(Taicpu.op_reg_ref(A_STR,NR_R0,href));
                 end
               else
                 begin
                    current_asmdata.getjumplabel(again);
                    list.concat(Taicpu.op_reg_const(A_MOV,NR_R12,localsize div winstackpagesize));
                    a_label(list,again);
                    { always shifterop }
                    list.concat(Taicpu.op_reg_reg_const(A_SUB,NR_STACK_POINTER_REG,NR_STACK_POINTER_REG,winstackpagesize));
                    reference_reset_base(href,NR_STACK_POINTER_REG,0);
                    { the data stored doesn't matter }
                    list.concat(Taicpu.op_reg_ref(A_STR,NR_R0,href));
                    list.concat(Taicpu.op_reg_reg_const(A_SUB,NR_R12,NR_R12,1));
                    a_jmp_cond(list,OC_NE,again);
                    if is_shifter_const(localsize mod winstackpagesize,shift) then
                      list.concat(Taicpu.op_reg_reg_const(A_SUB,NR_STACK_POINTER_REG,NR_STACK_POINTER_REG,localsize mod winstackpagesize))
                    else
                      begin
                        a_load_const_reg(list,OS_ADDR,localsize mod winstackpagesize,NR_R12);
                        list.concat(taicpu.op_reg_reg_reg(A_SUB,NR_STACK_POINTER_REG,NR_STACK_POINTER_REG,NR_R12));
                      end;
                    a_reg_dealloc(list,NR_R12);
                    reference_reset_base(href,NR_STACK_POINTER_REG,0);
                    { the data stored doesn't matter }
                    list.concat(Taicpu.op_reg_ref(A_STR,NR_R0,href));
                 end
             end
            else
            }
            if LocalSize<>0 then
              if not(is_shifter_const(localsize,shift)) then
                begin
                  if current_procinfo.framepointer=NR_STACK_POINTER_REG then
                    a_reg_alloc(list,NR_R12);
                  a_load_const_reg(list,OS_ADDR,LocalSize,NR_R12);
                  list.concat(taicpu.op_reg_reg_reg(A_SUB,NR_STACK_POINTER_REG,NR_STACK_POINTER_REG,NR_R12));
                  a_reg_dealloc(list,NR_R12);
                end
              else
                begin
                  a_reg_dealloc(list,NR_R12);
                  list.concat(taicpu.op_reg_reg_const(A_SUB,NR_STACK_POINTER_REG,NR_STACK_POINTER_REG,LocalSize));
                end;

            if firstfloatreg<>RS_NO then
              begin
                reference_reset(ref);
                if tg.direction*tarmprocinfo(current_procinfo).floatregstart>=1023 then
                  begin
                    a_load_const_reg(list,OS_ADDR,-tarmprocinfo(current_procinfo).floatregstart,NR_R12);
                    list.concat(taicpu.op_reg_reg_reg(A_SUB,NR_R12,current_procinfo.framepointer,NR_R12));
                    ref.base:=NR_R12;
                  end
                else
                  begin
                    ref.base:=current_procinfo.framepointer;
                    ref.offset:=tarmprocinfo(current_procinfo).floatregstart;
                  end;
                list.concat(taicpu.op_reg_const_ref(A_SFM,newreg(R_FPUREGISTER,firstfloatreg,R_SUBWHOLE),
                  lastfloatreg-firstfloatreg+1,ref));
              end;
          end;
}
      end;


    procedure tcgavr.g_proc_exit(list : TAsmList;parasize : longint;nostackframe:boolean);
{
      var
         ref : treference;
         firstfloatreg,lastfloatreg,
         r : byte;
         shift : byte;
         regs : tcpuregisterset;
         LocalSize : longint;
}
      begin
        internalerror(2011021318);
{
        if not(nostackframe) then
          begin
            { restore floating point register }
            firstfloatreg:=RS_NO;
            { save floating point registers? }
            for r:=RS_F0 to RS_F7 do
              if r in rg[R_FPUREGISTER].used_in_proc-paramanager.get_volatile_registers_fpu(pocall_stdcall) then
                begin
                  if firstfloatreg=RS_NO then
                    firstfloatreg:=r;
                  lastfloatreg:=r;
                end;

            if firstfloatreg<>RS_NO then
              begin
                reference_reset(ref);
                if tg.direction*tarmprocinfo(current_procinfo).floatregstart>=1023 then
                  begin
                    a_load_const_reg(list,OS_ADDR,-tarmprocinfo(current_procinfo).floatregstart,NR_R12);
                    list.concat(taicpu.op_reg_reg_reg(A_SUB,NR_R12,current_procinfo.framepointer,NR_R12));
                    ref.base:=NR_R12;
                  end
                else
                  begin
                    ref.base:=current_procinfo.framepointer;
                    ref.offset:=tarmprocinfo(current_procinfo).floatregstart;
                  end;
                list.concat(taicpu.op_reg_const_ref(A_LFM,newreg(R_FPUREGISTER,firstfloatreg,R_SUBWHOLE),
                  lastfloatreg-firstfloatreg+1,ref));
              end;

            if (current_procinfo.framepointer=NR_STACK_POINTER_REG) then
              begin
                LocalSize:=current_procinfo.calc_stackframe_size;
                if LocalSize<>0 then
                  if not(is_shifter_const(LocalSize,shift)) then
                    begin
                      a_reg_alloc(list,NR_R12);
                      a_load_const_reg(list,OS_ADDR,LocalSize,NR_R12);
                      list.concat(taicpu.op_reg_reg_reg(A_ADD,NR_STACK_POINTER_REG,NR_STACK_POINTER_REG,NR_R12));
                      a_reg_dealloc(list,NR_R12);
                    end
                  else
                    begin
                      list.concat(taicpu.op_reg_reg_const(A_ADD,NR_STACK_POINTER_REG,NR_STACK_POINTER_REG,LocalSize));
                    end;

                regs:=rg[R_INTREGISTER].used_in_proc-paramanager.get_volatile_registers_int(pocall_stdcall);
                if (pi_do_call in current_procinfo.flags) or (regs<>[]) then
                  begin
                    exclude(regs,RS_R14);
                    include(regs,RS_R15);
                  end;
                if regs=[] then
                  list.concat(taicpu.op_reg_reg(A_MOV,NR_R15,NR_R14))
                else
                  begin
                    reference_reset(ref);
                    ref.index:=NR_STACK_POINTER_REG;
                    ref.addressmode:=AM_PREINDEXED;
                    list.concat(setoppostfix(taicpu.op_ref_regset(A_LDM,ref,regs),PF_FD));
                  end;
              end
            else
              begin
                { restore int registers and return }
                reference_reset(ref);
                ref.index:=NR_FRAME_POINTER_REG;
                list.concat(setoppostfix(taicpu.op_ref_regset(A_LDM,ref,rg[R_INTREGISTER].used_in_proc-paramanager.get_volatile_registers_int(pocall_stdcall)+[RS_R11,RS_R13,RS_R15]),PF_EA));
              end;
          end
        else
          list.concat(taicpu.op_reg_reg(A_MOV,NR_PC,NR_R14));
}
      end;


    procedure tcgavr.a_loadaddr_ref_reg(list : TAsmList;const ref : treference;r : tregister);
      begin
        internalerror(2011021319);
      end;


    procedure tcgavr.fixref(list : TAsmList;var ref : treference);
      begin
        internalerror(2011021320);
      end;


    procedure tcgavr.g_concatcopy_move(list : TAsmList;const source,dest : treference;len : aint);
      var
        paraloc1,paraloc2,paraloc3 : TCGPara;
      begin
        paraloc1.init;
        paraloc2.init;
        paraloc3.init;
        paramanager.getintparaloc(pocall_default,1,paraloc1);
        paramanager.getintparaloc(pocall_default,2,paraloc2);
        paramanager.getintparaloc(pocall_default,3,paraloc3);
        a_load_const_cgpara(list,OS_INT,len,paraloc3);
        a_loadaddr_ref_cgpara(list,dest,paraloc2);
        a_loadaddr_ref_cgpara(list,source,paraloc1);
        paramanager.freecgpara(list,paraloc3);
        paramanager.freecgpara(list,paraloc2);
        paramanager.freecgpara(list,paraloc1);
        alloccpuregisters(list,R_INTREGISTER,paramanager.get_volatile_registers_int(pocall_default));
        a_call_name_static(list,'FPC_MOVE');
        dealloccpuregisters(list,R_INTREGISTER,paramanager.get_volatile_registers_int(pocall_default));
        paraloc3.done;
        paraloc2.done;
        paraloc1.done;
      end;


    procedure tcgavr.g_concatcopy_internal(list : TAsmList;const source,dest : treference;len : aint;aligned : boolean);
      begin
        internalerror(2011021321);
      end;

    procedure tcgavr.g_concatcopy_unaligned(list : TAsmList;const source,dest : treference;len : aint);
      begin
        g_concatcopy_internal(list,source,dest,len,false);
      end;


    procedure tcgavr.g_concatcopy(list : TAsmList;const source,dest : treference;len : aint);
      begin
        if (source.alignment in [1..3]) or
          (dest.alignment in [1..3]) then
          g_concatcopy_internal(list,source,dest,len,false)
        else
          g_concatcopy_internal(list,source,dest,len,true);
      end;


    procedure tcgavr.g_overflowCheck(list : TAsmList;const l : tlocation;def : tdef);
      var
        ovloc : tlocation;
      begin
        ovloc.loc:=LOC_VOID;
        g_overflowCheck_loc(list,l,def,ovloc);
      end;


    procedure tcgavr.g_overflowCheck_loc(List:TAsmList;const Loc:TLocation;def:TDef;ovloc : tlocation);
      begin
        internalerror(2011021322);
      end;

{
    procedure tcgavr.g_save_registers(list : TAsmList);
      begin
        { this work is done in g_proc_entry }
      end;


    procedure tcgavr.g_restore_registers(list : TAsmList);
      begin
        { this work is done in g_proc_exit }
      end;
}

    procedure tcgavr.a_jmp_cond(list : TAsmList;cond : TOpCmp;l: tasmlabel);
      var
        ai : taicpu;
      begin
        ai:=Taicpu.Op_sym(A_BRxx,l);
        ai.SetCondition(OpCmp2AsmCond[cond]);
        ai.is_jmp:=true;
        list.concat(ai);
      end;


    procedure tcgavr.g_intf_wrapper(list: TAsmList; procdef: tprocdef; const labelname: string; ioffset: longint);
      begin
        internalerror(2011021324);
      end;


    procedure tcgavr.emit_mov(list: TAsmList;reg2: tregister; reg1: tregister);
      var
         instr: taicpu;
      begin
       list.concat(taicpu.op_reg_reg(A_MOV, reg2, reg1));
       list.Concat(instr);
       { Notify the register allocator that we have written a move instruction so
         it can try to eliminate it. }
       add_move_instruction(instr);
      end;


    procedure tcg64favr.a_op64_reg_reg(list : TAsmList;op:TOpCG;size : tcgsize;regsrc,regdst : tregister64);
      begin
        internalerror(2011021325);
      end;


    procedure tcg64favr.a_op64_const_reg(list : TAsmList;op:TOpCG;size : tcgsize;value : int64;reg : tregister64);
      begin
        a_op64_const_reg_reg(list,op,size,value,reg,reg);
      end;


    procedure tcg64favr.a_op64_const_reg_reg(list: TAsmList;op:TOpCG;size : tcgsize;value : int64;regsrc,regdst : tregister64);
      var
        ovloc : tlocation;
      begin
        a_op64_const_reg_reg_checkoverflow(list,op,size,value,regsrc,regdst,false,ovloc);
      end;


    procedure tcg64favr.a_op64_reg_reg_reg(list: TAsmList;op:TOpCG;size : tcgsize;regsrc1,regsrc2,regdst : tregister64);
      var
        ovloc : tlocation;
      begin
        a_op64_reg_reg_reg_checkoverflow(list,op,size,regsrc1,regsrc2,regdst,false,ovloc);
      end;


    procedure tcg64favr.a_op64_const_reg_reg_checkoverflow(list: TAsmList;op:TOpCG;size : tcgsize;value : int64;regsrc,regdst : tregister64;setflags : boolean;var ovloc : tlocation);
      begin
        internalerror(2011021326);
      end;


    procedure tcg64favr.a_op64_reg_reg_reg_checkoverflow(list: TAsmList;op:TOpCG;size : tcgsize;regsrc1,regsrc2,regdst : tregister64;setflags : boolean;var ovloc : tlocation);
      begin
        internalerror(2011021327);
      end;


    procedure create_codegen;
      begin
        cg:=tcgavr.create;
        cg64:=tcg64favr.create;
      end;
      
end.