freepascal.compiler/compiler/ag68kgas.pas

{
    $Id$
    Copyright (c) 1998 by the FPC development team

    This unit implements an asmoutput class for MOTOROLA syntax with
    Motorola 68000 (for GAS v2.52 AND HIGER)

    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.

 ****************************************************************************

  What's to do:
    o Verify if this actually work as indirect mode with name of variables
    o write lines numbers and file names to output file
    o generate debugging informations
}
unit ag68kgas;

    interface

    uses aasm,assemble;

    type
      pm68kgasasmlist=^tm68kgasasmlist;
      tm68kgasasmlist = object(tasmlist)
        procedure WriteTree(p:paasmoutput);virtual;
        procedure WriteAsmList;virtual;
      end;

   implementation

    uses
      dos,globals,systems,cobjects,m68k,
      strings,files,verbose
{$ifdef GDB}
      ,gdb
{$endif GDB}
      ;

    const
      line_length = 70;

    var
      infile : pextfile;
      includecount,lastline : longint;

    function getreferencestring(const ref : treference) : string;
      var
         s : string;
      begin
         s:='';
         if ref.isintvalue then
             s:='#'+tostr(ref.offset)
         else
           with ref do
             begin
                if assigned(symbol) then
                  s:=s+symbol^;

                if offset<0 then s:=s+tostr(offset)
                  else if (offset>0) then
                    begin
                       if (symbol=nil) then s:=tostr(offset)
                       else s:=s+'+'+tostr(offset);
                    end;
               if (index<>R_NO) and (base=R_NO) and (direction=dir_none) then
                begin
                  if (scalefactor = 1) or (scalefactor = 0) then
                    s:=s+'(,'+gas_reg2str[index]+'.l)'
                  else
                    s:=s+'(,'+gas_reg2str[index]+'.l*'+tostr(scalefactor)+')'
                end
                else if (index=R_NO) and (base<>R_NO) and (direction=dir_inc) then
                begin
                  if (scalefactor = 1) or (scalefactor = 0) then
                      s:=s+'('+gas_reg2str[base]+')+'
                  else
                   InternalError(10002);
                end
                else if (index=R_NO) and (base<>R_NO) and (direction=dir_dec) then
                begin
                  if (scalefactor = 1) or (scalefactor = 0) then
                      s:=s+'-('+gas_reg2str[base]+')'
                  else
                   InternalError(10003);
                end
                  else if (index=R_NO) and (base<>R_NO) and (direction=dir_none) then
                begin
                  s:=s+'('+gas_reg2str[base]+')'
                end
                  else if (index<>R_NO) and (base<>R_NO) and (direction=dir_none) then
                begin
                  if (scalefactor = 1) or (scalefactor = 0) then
                    s:=s+'('+gas_reg2str[base]+','+gas_reg2str[index]+'.l)'
                  else
                    s:=s+'('+gas_reg2str[base]+','+gas_reg2str[index]+'.l*'+tostr(scalefactor)+')';
                end;
            end; { end with }
         getreferencestring:=s;
      end;

    function getopstr(t : byte;o : pointer) : string;

      var
         hs : string;
         i: tregister;

      begin
         case t of
            top_reg : getopstr:=gas_reg2str[tregister(o)];
               top_ref : getopstr:=getreferencestring(preference(o)^);
         top_reglist: begin
                      hs:='';
                      for i:=R_NO to R_FPSR do
                      begin
                        if i in tregisterlist(o^) then
                         hs:=hs+gas_reg2str[i]+'/';
                      end;
                      delete(hs,length(hs),1);
                      getopstr := hs;
                    end;
             top_const : getopstr:='#'+tostr(longint(o));
            top_symbol :
                    { compare with i386, where a symbol is considered }
                    { a constant.                                     }
                    begin
                     hs[0]:=chr(strlen(pchar(pcsymbol(o)^.symbol)));
                            move(pchar(pcsymbol(o)^.symbol)^,hs[1],byte(hs[0]));
{                           inc(byte(hs[0]));}
                            if pcsymbol(o)^.offset>0 then
                              hs:=hs+'+'+tostr(pcsymbol(o)^.offset)
                            else if pcsymbol(o)^.offset<0 then
                              hs:=hs+tostr(pcsymbol(o)^.offset);
                            getopstr:=hs;
                         end;
            else internalerror(10001);
         end;
      end;

    function getopstr_jmp(t : byte;o : pointer) : string;

      var
         hs : string;

      begin
         case t of
            top_reg : getopstr_jmp:=gas_reg2str[tregister(o)];
            top_ref : getopstr_jmp:=getreferencestring(preference(o)^);
            top_const : getopstr_jmp:=tostr(longint(o));
            top_symbol : begin
                            hs[0]:=chr(strlen(pchar(pcsymbol(o)^.symbol)));
                            move(pchar(pcsymbol(o)^.symbol)^,hs[1],byte(hs[0]));
                            if pcsymbol(o)^.offset>0 then
                              hs:=hs+'+'+tostr(pcsymbol(o)^.offset)
                            else if pcsymbol(o)^.offset<0 then
                              hs:=hs+tostr(pcsymbol(o)^.offset);
                            getopstr_jmp:=hs;
                         end;
            else internalerror(10001);
         end;
      end;

{****************************************************************************
                             T68kGASASMOUTPUT
 ****************************************************************************}

    var
       { different types of source lines }
       n_line : byte;

    const
      ait_const2str:array[ait_const_32bit..ait_const_8bit] of string[8]=
        (#9'.long'#9,'',#9'.short'#9,#9'.byte'#9);

    procedure tm68kgasasmlist.WriteTree(p:paasmoutput);
    var
      hp        : pai;
      ch        : char;
      consttyp  : tait;
      s         : string;
      pos,l,i   : longint;
      found     : boolean;
{$ifdef GDB}
      funcname  : pchar;
      linecount : longint;
{$endif GDB}
    begin
{$ifdef GDB}
      funcname:=nil;
      linecount:=1;
{$endif GDB}
      hp:=pai(p^.first);
      while assigned(hp) do
       begin
       { write debugger informations }
{$ifdef GDB}
         if cs_debuginfo in aktswitches then
          begin
            if not (hp^.typ in  [ait_external,ait_stabn,ait_stabs,ait_stab_function_name]) then
             begin
               if assigned(hp^.infile) and (pextfile(hp^.infile)<>infile)  then
                begin
                  infile:=hp^.infile;
                  inc(includecount);
                  if (hp^.infile^.path^<>'') then
                   begin
                     AsmWriteLn(#9'.stabs "'+FixPath(hp^.infile^.path^)+'",'+tostr(n_includefile)+
                                ',0,0,Ltext'+ToStr(IncludeCount));
                   end;
                  AsmWriteLn(#9'.stabs "'+FixFileName(hp^.infile^.name^+hp^.infile^.ext^)+'",'+tostr(n_includefile)+
                             ',0,0,Ltext'+ToStr(IncludeCount));
                  AsmWriteLn('Ltext'+ToStr(IncludeCount)+':');
                end;
              { file name must be there before line number ! }
               if (hp^.line<>lastline) and (hp^.line<>0) then
                begin
                  if (n_line = n_textline) and assigned(funcname) and
                     (target_info.use_function_relative_addresses) then
                   begin
                     AsmWriteLn(target_info.labelprefix+'l'+tostr(linecount)+':');
                     AsmWriteLn(#9'.stabn '+tostr(n_line)+',0,'+tostr(hp^.line)+','+
                                target_info.labelprefix+'l'+tostr(linecount)+' - '+StrPas(FuncName));
                     inc(linecount);
                   end
                  else
                   AsmWriteLn(#9'.stabd'#9+tostr(n_line)+',0,'+tostr(hp^.line));
                  lastline:=hp^.line;
                end;
             end;
          end;
{$endif GDB}

         case hp^.typ of
       ait_comment,
      ait_external : ; { external is ignored }
         ait_align : AsmWriteLn(#9'.align '+tostr(pai_align(hp)^.aligntype));
     ait_datablock : begin
                       { ------------------------------------------------------- }
                       { ----------- ALIGNMENT FOR ANY NON-BYTE VALUE ---------- }
                       { ------------- REQUIREMENT FOR 680x0 ------------------- }
                       { ------------------------------------------------------- }
                       if pai_datablock(hp)^.size <> 1 then
                        begin
                          if not(cs_littlesize in aktswitches) then
                           AsmWriteLn(#9#9'.align 4')
                          else
                           AsmWriteLn(#9#9'.align 2');
                        end;
                       if pai_datablock(hp)^.is_global then
                        AsmWrite(#9'.comm'#9)
                       else
                        AsmWrite(#9'.lcomm'#9);
                       AsmWriteLn(StrPas(pai_datablock(hp)^.name)+','+tostr(pai_datablock(hp)^.size));
                     end;
   ait_const_32bit, { alignment is required for 16/32 bit data! }
   ait_const_16bit:  begin
                      if not(cs_littlesize in aktswitches) then
                           AsmWriteLn(#9#9'.align 4')
                      else
                          AsmWriteLn(#9#9'.align 2');
                       AsmWrite(ait_const2str[hp^.typ]+tostr(pai_const(hp)^.value));
                       consttyp:=hp^.typ;
                       l:=0;
                       repeat
                         found:=(not (Pai(hp^.next)=nil)) and (Pai(hp^.next)^.typ=consttyp);
                         if found then
                          begin
                            hp:=Pai(hp^.next);
                            s:=','+tostr(pai_const(hp)^.value);
                            AsmWrite(s);
                            inc(l,length(s));
                          end;
                       until (not found) or (l>line_length);
                       AsmLn;
                     end;
    ait_const_8bit : begin
                       AsmWrite(ait_const2str[hp^.typ]+tostr(pai_const(hp)^.value));
                       consttyp:=hp^.typ;
                       l:=0;
                       repeat
                         found:=(not (Pai(hp^.next)=nil)) and (Pai(hp^.next)^.typ=consttyp);
                         if found then
                          begin
                            hp:=Pai(hp^.next);
                            s:=','+tostr(pai_const(hp)^.value);
                            AsmWrite(s);
                            inc(l,length(s));
                          end;
                       until (not found) or (l>line_length);
                       AsmLn;
                     end;
  ait_const_symbol : Begin
                      if not(cs_littlesize in aktswitches) then
                           AsmWriteLn(#9#9'.align 4')
                      else
                          AsmWriteLn(#9#9'.align 2');
                       AsmWriteLn(#9'.long'#9+StrPas(pchar(pai_const(hp)^.value)));
                     end;
    ait_real_64bit : Begin
                      if not(cs_littlesize in aktswitches) then
                           AsmWriteLn(#9#9'.align 4')
                      else
                          AsmWriteLn(#9#9'.align 2');
                      AsmWriteLn(#9'.double'#9+double2str(pai_double(hp)^.value));
                     end;
    ait_real_32bit : Begin
                      if not(cs_littlesize in aktswitches) then
                           AsmWriteLn(#9#9'.align 4')
                      else
                          AsmWriteLn(#9#9'.align 2');
                      AsmWriteLn(#9'.single'#9+double2str(pai_single(hp)^.value));
                     end;
 ait_real_extended : Begin
                      if not(cs_littlesize in aktswitches) then
                           AsmWriteLn(#9#9'.align 4')
                      else
                          AsmWriteLn(#9#9'.align 2');
                      AsmWriteLn(#9'.extend'#9+double2str(pai_extended(hp)^.value));
                     { comp type is difficult to write so use double }
                     end;
          ait_comp : Begin
                      if not(cs_littlesize in aktswitches) then
                           AsmWriteLn(#9#9'.align 4')
                      else
                          AsmWriteLn(#9#9'.align 2');
                       AsmWriteLn(#9'.double'#9+comp2str(pai_extended(hp)^.value));
                     end;
        ait_direct : begin
                       AsmWritePChar(pai_direct(hp)^.str);
                       AsmLn;
{$IfDef GDB}
                       if strpos(pai_direct(hp)^.str,'.data')<>nil then
                         n_line:=n_dataline
                       else if strpos(pai_direct(hp)^.str,'.text')<>nil then
                         n_line:=n_textline
                       else if strpos(pai_direct(hp)^.str,'.bss')<>nil then
                         n_line:=n_bssline;
{$endif GDB}
                     end;
        ait_string : begin
                       pos:=0;
                       for i:=1 to pai_string(hp)^.len do
                        begin
                          if pos=0 then
                           begin
                             AsmWrite(#9'.ascii'#9'"');
                             pos:=20;
                           end;
                          ch:=pai_string(hp)^.str[i-1];
                          case ch of
                             #0, {This can't be done by range, because a bug in FPC}
                        #1..#31,
                     #128..#255 : s:='\'+tostr(ord(ch) shr 6)+tostr((ord(ch) and 63) shr 3)+tostr(ord(ch) and 7);
                            '"' : s:='\"';
                            '\' : s:='\\';
                          else
                           s:=ch;
                          end;
                          AsmWrite(s);
                          inc(pos,length(s));
                          if (pos>line_length) or (i=pai_string(hp)^.len) then
                           begin
                             AsmWriteLn('"');
                             pos:=0;
                           end;
                        end;
                     end;
         ait_label : begin
                       if (pai_label(hp)^.l^.is_used) then
                        AsmWriteLn(lab2str(pai_label(hp)^.l)+':');
                     end;
ait_labeled_instruction : begin
                     { labeled operand }
                       if pai_labeled(hp)^._op1 = R_NO then
                        AsmWriteLn(#9+mot_op2str[pai_labeled(hp)^._operator]+#9+lab2str(pai_labeled(hp)^.lab))
                       else
                     { labeled operand with register }
                        AsmWriteLn(#9+mot_op2str[pai_labeled(hp)^._operator]+#9+
                                 reg2str(pai_labeled(hp)^._op1)+','+lab2str(pai_labeled(hp)^.lab))
                     end;
        ait_symbol : begin
                       { ------------------------------------------------------- }
                       { ----------- ALIGNMENT FOR ANY NON-BYTE VALUE ---------- }
                       { ------------- REQUIREMENT FOR 680x0 ------------------- }
                       { ------------------------------------------------------- }
                       if assigned(hp^.next) and (pai(hp^.next)^.typ in
                          [ait_const_32bit,ait_const_16bit,ait_const_symbol,
                           ait_real_64bit,ait_real_32bit,ait_string]) then
                        begin
                          if not(cs_littlesize in aktswitches) then
                           AsmWriteLn(#9#9'.align 4')
                          else
                           AsmWriteLn(#9#9'.align 2');
                        end;
                       if pai_symbol(hp)^.is_global then
                        AsmWriteLn('.globl '+StrPas(pai_symbol(hp)^.name));
                       AsmWriteLn(StrPas(pai_symbol(hp)^.name)+':');
                     end;
   ait_instruction : begin
                       { old versions of GAS don't like PEA.L and LEA.L }
                       if (pai68k(hp)^._operator <> A_LEA) and (pai68k(hp)^._operator<> A_PEA) then
                           s:=#9+mot_op2str[pai68k(hp)^._operator]+gas_opsize2str[pai68k(hp)^.size]
                       else
                           s:=#9+mot_op2str[pai68k(hp)^._operator];
                       if pai68k(hp)^.op1t<>top_none then
                        begin
                        { call and jmp need an extra handling                          }
                        { this code is only callded if jmp isn't a labeled instruction }
                          if pai68k(hp)^._operator in [A_JSR,A_JMP] then
                           s:=s+#9+getopstr_jmp(pai68k(hp)^.op1t,pai68k(hp)^.op1)
                          else
                           if pai68k(hp)^.op1t = top_reglist then
                            s:=s+#9+getopstr(pai68k(hp)^.op1t,@(pai68k(hp)^.reglist))
                           else
                            s:=s+#9+getopstr(pai68k(hp)^.op1t,pai68k(hp)^.op1);
                           if pai68k(hp)^.op2t<>top_none then
                            begin
                              if pai68k(hp)^.op2t = top_reglist then
                               s:=s+','+getopstr(pai68k(hp)^.op2t,@pai68k(hp)^.reglist)
                              else
                               s:=s+','+getopstr(pai68k(hp)^.op2t,pai68k(hp)^.op2);
                            { three operands }
                              if pai68k(hp)^.op3t<>top_none then
                               begin
                                   if (pai68k(hp)^._operator = A_DIVSL) or
                                      (pai68k(hp)^._operator = A_DIVUL) or
                                      (pai68k(hp)^._operator = A_MULU) or
                                      (pai68k(hp)^._operator = A_MULS) or
                                      (pai68k(hp)^._operator = A_DIVS) or
                                      (pai68k(hp)^._operator = A_DIVU) then
                                    s:=s+':'+getopstr(pai68k(hp)^.op3t,pai68k(hp)^.op3)
                                   else
                                    s:=s+','+getopstr(pai68k(hp)^.op3t,pai68k(hp)^.op3);
                               end;
                            end;
                        end;
                       AsmWriteLn(s);
                     end;
{$ifdef GDB}
         ait_stabs : begin
                       AsmWrite(#9'.stabs ');
                       AsmWritePChar(pai_stabs(hp)^.str);
                       AsmLn;
                     end;
         ait_stabn : begin
                       AsmWrite(#9'.stabn ');
                       AsmWritePChar(pai_stabn(hp)^.str);
                       AsmLn;
                     end;
ait_stab_function_name : funcname:=pai_stab_function_name(hp)^.str;
{$endif GDB}
         else
          internalerror(10000);
         end;
         hp:=pai(hp^.next);
       end;
    end;

    procedure tm68kgasasmlist.WriteAsmList;
{$ifdef GDB}
    var
      p,n,e : string;
{$endif}
    begin
{$ifdef EXTDEBUG}
      if assigned(current_module^.mainsource) then
       comment(v_info,'Start writing gas-styled assembler output for '+current_module^.mainsource^);
{$endif}
      infile:=nil;
      includecount:=0;
{$ifdef GDB}
      if assigned(current_module^.mainsource) then
       fsplit(current_module^.mainsource^,p,n,e)
      else
       begin
         p:=inputdir;
         n:=inputfile;
         e:=inputextension;
       end;
    { to get symify to work }
      AsmWriteLn(#9'.file "'+FixFileName(n+e)+'"');
    { stabs }
      n_line:=n_bssline;
      if (cs_debuginfo in aktswitches) then
       begin
         if (p<>'') then
          AsmWriteLn(#9'.stabs "'+FixPath(p)+'",'+tostr(n_sourcefile)+',0,0,Ltext0');
         AsmWriteLn(#9'.stabs "'+FixFileName(n+e)+'",'+tostr(n_sourcefile)+',0,0,Ltext0');
         AsmWriteLn('Ltext0:');
       end;
      infile:=current_module^.sourcefiles.files;
{$endif GDB}

    { main source file is last in list }
      while assigned(infile^._next) do
       infile:=infile^._next;
      lastline:=0;
      { there should be nothing but externals so we don't need to process
      WriteTree(externals); }
      WriteTree(debuglist);

    { code segment }
      AsmWriteln('.text');
{$ifdef GDB}
      n_line:=n_textline;
{$endif GDB}
      WriteTree(codesegment);

      AsmWriteLn('.data');
{$ifdef EXTDEBUG}
      AsmWriteLn(#9'.ascii'#9'"compiled by FPC '+version_string+'\0"');
      AsmWriteLn(#9'.ascii'#9'"target: '+target_info.target_name+'\0"');
{$endif EXTDEBUG}
{$ifdef GDB}
      n_line:=n_dataline;
{$endif GDB}
      DataSegment^.insert(new(pai_align,init(4)));
      WriteTree(datasegment);
      WriteTree(consts);

    { makes problems with old GNU ASes
      AsmWriteLn('.bss');
      bssSegment^.insert(new(pai_align,init(4))); }
{$ifdef GDB}
      n_line:=n_bssline;
{$endif GDB}
      WriteTree(bsssegment);

      AsmLn;
{$ifdef EXTDEBUG}
      if assigned(current_module^.mainsource) then
       comment(v_info,'Done writing gas-styled assembler output for '+current_module^.mainsource^);
{$endif EXTDEBUG}
    end;

end.
{
  $Log$
  Revision 1.1  1998-03-25 11:18:16  root
  Initial revision

  Revision 1.3  1998/03/22 12:45:37  florian
    * changes of Carl-Eric to m68k target commit:
      - wrong nodes because of the new string cg in intel, I had to create
        this under m68k also ... had to work it out to fix potential alignment
        problems --> this removes the crash of the m68k compiler.
      - added absolute addressing in m68k assembler (required for Amiga startup)
      - fixed alignment problems (because of byte return values, alignment
        would not be always valid) -- is this ok if i change the offset if odd in
        setfirsttemp ?? -- it seems ok...

  Revision 1.2  1998/03/10 04:22:08  carl
    - removed in as it can cause range check errors under BP

  Revision 1.1  1998/03/10 01:26:10  peter
    + new uniform names

  Revision 1.18  1998/03/09 12:58:10  peter
    * FWait warning is only showed for Go32V2 and $E+
    * opcode tables moved to i386.pas/m68k.pas to reduce circular uses (and
      for m68k the same tables are removed)
    + $E for i386

  Revision 1.17  1998/03/06 00:52:18  peter
    * replaced all old messages from errore.msg, only ExtDebug and some
      Comment() calls are left
    * fixed options.pas

  Revision 1.16  1998/03/02 01:48:33  peter
    * renamed target_DOS to target_GO32V1
    + new verbose system, merged old errors and verbose units into one new
      verbose.pas, so errors.pas is obsolete

  Revision 1.15  1998/02/23 03:00:00  carl
    * bugfix when compiling with extdebug defined

  Revision 1.14  1998/02/22 23:03:18  peter
    * renamed msource->mainsource and name->unitname
    * optimized filename handling, filename is not seperate anymore with
      path+name+ext, this saves stackspace and a lot of fsplit()'s
    * recompiling of some units in libraries fixed
    * shared libraries are working again
    + $LINKLIB <lib> to support automatic linking to libraries
    + libraries are saved/read from the ppufile, also allows more libraries
      per ppufile

  Revision 1.13  1998/02/21 20:20:52  carl
     * make it work under older versions of GAS

  Revision 1.10  1998/02/15 21:16:19  peter
    * all assembler outputs supported by assemblerobject
    * cleanup with assembleroutputs, better .ascii generation
    * help_constructor/destructor are now added to the externals
    - generation of asmresponse is not outputformat depended

  Revision 1.9  1998/02/13 10:34:59  daniel
  * Made Motorola version compilable.
  * Fixed optimizer

  Revision 1.8  1998/02/12 11:50:04  daniel
  Yes! Finally! After three retries, my patch!

  Changes:

  Complete rewrite of psub.pas.
  Added support for DLL's.
  Compiler requires less memory.
  Platform units for each platform.

  Revision 1.7  1998/01/09 19:20:49  carl
  + added support for mul/div 68020 syntax
  * bugfix of getreferencestring

  Revision 1.4  1997/12/09 13:37:50  carl
  + ait_align added
  * now all non byte values are aligned correctly

  Revision 1.3  1997/12/05 14:40:49  carl
  * bugfix of scaling, was incorrect under gas.

  Revision 1.2  1997/12/04 15:30:14  carl
  * forgot to change name of unit! ugh...

  Revision 1.1  1997/12/03 14:04:19  carl
  + renamed from gasasm6.pas to ag68kgas.pas

  Revision 1.3  1997/12/01 17:42:51  pierre
     + added some more functionnality to the assembler parser

  Revision 1.2  1997/11/28 18:14:32  pierre
   working version with several bug fixes

  Revision 1.1.1.1  1997/11/27 08:32:56  michael
  FPC Compiler CVS start


  Pre-CVS log:

  CEC   Carl-Eric Codere
  FK    Florian Klaempfl
  PM    Pierre Muller
  +     feature added
  -     removed
  *     bug fixed or changed

  History:
      30th september 1996:
         + unit started (FK)
      15th october 1996:
         + ti386attasmoutput class started (FK)
      28th november 1996:
         ! debugging for simple programs (FK)
      26th february 1997:
         + op2str array completed with work of Daniel Manitone (FK)
      25th september 1997:
         * compiled by comment ifdef'ed (FK)
      4th october 1997:
         + converted to motorola 68000 (same sytnax as gas) (CEC)
     9th october 1997:
       * fixed constant bug. (CEC)
       + converted from %reg to reg (untested) (CEC)
     (according to gas docs, they are accepted).
    28th october 1997:
       * bugfix on increment/decrement mode (was never checked). (CEC)
    2nd november 1997:
       + added all opcodes , and they are now in correct order of
         processor types. (CEC).
}