{
    Copyright (c) 1998-2002 by Florian Klaempfl

    This unit implements an asmoutput class for Intel syntax with Intel i386+

    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.

 ****************************************************************************
}
{
  This unit implements an asmoutput class for Intel syntax with Intel i386+
}
unit agx86int;

{$i fpcdefs.inc}

interface

    uses
      cpubase,constexp,
      aasmbase,aasmtai,aasmdata,aasmcpu,assemble,cgutils;

    type
      Tx86IntelAssembler = class(TExternalAssembler)
      private
        procedure WriteReference(var ref : treference);
        procedure WriteOper(const o:toper;s : topsize; opcode: tasmop;dest : boolean);
        procedure WriteOper_jmp(const o:toper;s : topsize);
      public
        function single2str(d : single) : string; override;
        function double2str(d : double) : string; override;
        function extended2str(e : extended) : string; override;
        function comp2str(d : bestreal) : string;
        procedure WriteTree(p:TAsmList);override;
        procedure WriteAsmList;override;
        Function  DoAssemble:boolean;override;
        procedure WriteExternals;
      end;


implementation

    uses
      SysUtils,math,
      cutils,globtype,globals,systems,cclasses,
      verbose,cscript,cpuinfo,
      itx86int,
      cgbase
{$ifdef EXTDEBUG}
      ,fmodule
{$endif EXTDEBUG}
      ;

    const
      line_length = 70;
      max_tokens : longint = 25;

      wasm_cpu_name : array[tcputype] of string = (
{$if defined(x86_64)}
        'IA64',        // cpu_none,
        '686',         // cpu_athlon64,
        '686',        // cpu_core_i,
        '686',        // cpu_core_avx,
        '686'         // cpu_core_avx2
{$elseif defined(i386)}
        'IA64',     // cpu_none,
        '386',      // cpu_386,
        '486',      // cpu_486,
        '586',  // cpu_Pentium,
        '686',       // cpu_Pentium2,
        '686',       // cpu_Pentium3,
        '686',       // cpu_Pentium4,
        '686',       // cpu_PentiumM,
        '686',     // cpu_core_i,
        '686',     // cpu_core_avx,
        '686'      // cpu_core_avx2
{$elseif defined(i8086)}
        'IA64',    // cpu_none
        '8086',    // cpu_8086
        '186',     // cpu_186
        '286',     // cpu_286
        '386',     // cpu_386
        '486',     // cpu_486
        '586', // cpu_Pentium
        '686',      // cpu_Pentium2
        '686',      // cpu_Pentium3
        '686',      // cpu_Pentium4
        '686'       // cpu_PentiumM
{$endif}
      );
      secnames : array[TAsmSectiontype] of string[4] = ('','',
        'CODE','DATA','DATA','DATA','BSS','TLS',
        '','','','','','',
        '','','','',
        '',
        '',
        '',
        '',
        '',
        '','','','','','',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        ''
      );

      secnamesml64 : array[TAsmSectiontype] of string[7] = ('','',
        '_TEXT','_DATA','_DATA','_DATA','_BSS','_TLS',
        '','','','',
        'idata$2','idata$4','idata$5','idata$6','idata$7','edata',
        '',
        '',
        '',
        '',
        '',
        '','','','','','',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        '',
        ''
      );

    function TX86IntelAssembler.single2str(d : single) : string;
      var
         hs : string;
         p : byte;
      begin
         str(d,hs);
      { nasm expects a lowercase e }
         p:=pos('E',hs);
         if p>0 then
          hs[p]:='e';
         p:=pos('+',hs);
         if p>0 then
          delete(hs,p,1);
         single2str:=lower(hs);
      end;

    function TX86IntelAssembler.double2str(d : double) : string;
      var
         hs : string;
         p : byte;
      begin
         str(d,hs);
      { nasm expects a lowercase e }
         p:=pos('E',hs);
         if p>0 then
          hs[p]:='e';
         p:=pos('+',hs);
         if p>0 then
          delete(hs,p,1);
         double2str:=lower(hs);
      end;

    function TX86IntelAssembler.extended2str(e : extended) : string;
      var
         hs : string;
         p : byte;
      begin
         str(e,hs);
      { nasm expects a lowercase e }
         p:=pos('E',hs);
         if p>0 then
          hs[p]:='e';
         p:=pos('+',hs);
         if p>0 then
          delete(hs,p,1);
         extended2str:=lower(hs);
      end;


    function TX86IntelAssembler.comp2str(d : bestreal) : string;
      type
        pdouble = ^double;
      var
        c  : comp;
        dd : pdouble;
      begin
         c:=comp(d);
         dd:=pdouble(@c); { this makes a bitwise copy of c into a double }
         comp2str:=double2str(dd^);
      end;

    { MASM supports aligns up to 8192 }
    function alignstr(b : longint) : string;
      begin
        case b of
          1: result:='BYTE';
          2: result:='WORD';
          4: result:='DWORD';
          0,
          16: result:='PARA';
          256: result:='PAGE';
        else
          result:='ALIGN('+tostr(b)+')';
        end;
      end;

{****************************************************************************
                               tx86IntelAssembler
 ****************************************************************************}

    procedure tx86IntelAssembler.WriteReference(var ref : treference);
      var
        first : boolean;
      begin
        with ref do
         begin
           first:=true;
           if segment<>NR_NO then
            writer.AsmWrite(masm_regname(segment)+':[')
           else
            writer.AsmWrite('[');
           if assigned(symbol) then
            begin
              if (asminfo^.id = as_i386_tasm) then
                writer.AsmWrite('dword ptr ');
              writer.AsmWrite(symbol.name);
              first:=false;
            end;
           if (base<>NR_NO) then
            begin
              if not(first) then
               writer.AsmWrite('+')
              else
               first:=false;
{$ifdef x86_64}
              { ml64 needs [$+foo] instead of [rip+foo] }
              if (base=NR_RIP) and (asminfo^.id=as_x86_64_masm) then
               writer.AsmWrite('$')
              else
{$endif x86_64}
               writer.AsmWrite(masm_regname(base));
            end;
           if (index<>NR_NO) then
            begin
              if not(first) then
               writer.AsmWrite('+')
              else
               first:=false;
              writer.AsmWrite(masm_regname(index));
              if scalefactor<>0 then
               writer.AsmWrite('*'+tostr(scalefactor));
            end;
               if offset<0 then
                begin
                  writer.AsmWrite(tostr(offset));
                  first:=false;
                end
               else if (offset>0) then
                begin
                  writer.AsmWrite('+'+tostr(offset));
                  first:=false;
                end;
           if first then
             writer.AsmWrite('0');
           writer.AsmWrite(']');
         end;
      end;


    procedure tx86IntelAssembler.WriteOper(const o:toper;s : topsize; opcode: tasmop;dest : boolean);
      begin
        case o.typ of
          top_reg :
            writer.AsmWrite(masm_regname(o.reg));
          top_const :
            writer.AsmWrite(tostr(o.val));
          top_ref :
            begin
              if o.ref^.refaddr in [addr_no,addr_pic,addr_pic_no_got] then
                begin
                  if ((opcode <> A_LGS) and (opcode <> A_LSS) and
                      (opcode <> A_LFS)
{$ifndef x86_64}
                      and (opcode <> A_LDS) and (opcode <> A_LES)
{$endif x86_64}
                      ) then
                   Begin
                     case s of
                      S_B : writer.AsmWrite('byte ptr ');
                      S_W : writer.AsmWrite('word ptr ');
                      S_L : writer.AsmWrite('dword ptr ');
                      S_Q : writer.AsmWrite('qword ptr ');
                     S_IS : writer.AsmWrite('word ptr ');
                     S_IL : writer.AsmWrite('dword ptr ');
                     S_IQ : writer.AsmWrite('qword ptr ');
                     S_FS : writer.AsmWrite('dword ptr ');
                     S_FL : writer.AsmWrite('qword ptr ');
                     S_T,
                     S_FX : writer.AsmWrite('tbyte ptr ');
                     S_BW : if dest then
                             writer.AsmWrite('word ptr ')
                            else
                             writer.AsmWrite('byte ptr ');
                     S_BL : if dest then
                             writer.AsmWrite('dword ptr ')
                            else
                             writer.AsmWrite('byte ptr ');
                     S_WL : if dest then
                             writer.AsmWrite('dword ptr ')
                            else
                             writer.AsmWrite('word ptr ');
                     S_XMM: writer.AsmWrite('xmmword ptr ');
                     S_YMM: writer.AsmWrite('ymmword ptr ');
{$ifdef x86_64}
                     S_BQ : if dest then
                             writer.AsmWrite('qword ptr ')
                            else
                             writer.AsmWrite('byte ptr ');
                     S_WQ : if dest then
                             writer.AsmWrite('qword ptr ')
                            else
                             writer.AsmWrite('word ptr ');
                     S_LQ : if dest then
                             writer.AsmWrite('qword ptr ')
                            else
                             writer.AsmWrite('dword ptr ');

{$endif x86_64}
                     end;
                   end;
                  WriteReference(o.ref^);
                end
              else
                begin
                  writer.AsmWrite('offset ');
                  if assigned(o.ref^.symbol) then
                    writer.AsmWrite(o.ref^.symbol.name);
                  if o.ref^.offset>0 then
                   writer.AsmWrite('+'+tostr(o.ref^.offset))
                  else
                   if o.ref^.offset<0 then
                    writer.AsmWrite(tostr(o.ref^.offset))
                  else
                   if not(assigned(o.ref^.symbol)) then
                     writer.AsmWrite('0');
                end;
            end;
          else
            internalerror(2005060510);
        end;
      end;


    procedure tx86IntelAssembler.WriteOper_jmp(const o:toper;s : topsize);
    begin
      case o.typ of
        top_reg :
          writer.AsmWrite(masm_regname(o.reg));
        top_const :
          writer.AsmWrite(tostr(o.val));
        top_ref :
          { what about lcall or ljmp ??? }
          begin
            if o.ref^.refaddr=addr_no then
              begin
                if (asminfo^.id <> as_i386_tasm) then
                  begin
                    if s=S_FAR then
                      writer.AsmWrite('far ptr ')
                    else
{$ifdef x86_64}
                      writer.AsmWrite('qword ptr ');
{$else x86_64}
                      writer.AsmWrite('dword ptr ');
{$endif x86_64}
                  end;
                WriteReference(o.ref^);
              end
            else
              begin
                writer.AsmWrite(o.ref^.symbol.name);
                if o.ref^.offset>0 then
                 writer.AsmWrite('+'+tostr(o.ref^.offset))
                else
                 if o.ref^.offset<0 then
                  writer.AsmWrite(tostr(o.ref^.offset));
              end;
          end;
        else
          internalerror(2005060511);
      end;
    end;

    const
      ait_const2str : array[aitconst_128bit..aitconst_secrel32_symbol] of string[20]=(
        #9''#9,#9'DQ'#9,#9'DD'#9,#9'DW'#9,#9'DB'#9,
        #9'FIXMESLEB',#9'FIXEMEULEB',
        #9'DD RVA'#9,#9'DD SECREL32'#9
      );

    Function PadTabs(const p:string;addch:char):string;
    var
      s : string;
      i : longint;
    begin
      i:=length(p);
      if addch<>#0 then
       begin
         inc(i);
         s:=p+addch;
       end
      else
       s:=p;
      if i<8 then
       PadTabs:=s+#9#9
      else
       PadTabs:=s+#9;
    end;

    procedure tx86IntelAssembler.WriteTree(p:TAsmList);
    var
      s,
      prefix,
      suffix   : string;
      hp,nhp   : tai;
      cpu: tcputype;
      counter,
      lines, tokens,
      InlineLevel : longint;
      i,j,l    : longint;
      consttype : taiconst_type;
      do_line,DoNotSplitLine,
      quoted   : boolean;
      fixed_opcode: TAsmOp;
    begin
      if not assigned(p) then
       exit;
      { lineinfo is only needed for al_procedures (PFV) }
      do_line:=((cs_asm_source in current_settings.globalswitches) or
                (cs_lineinfo in current_settings.moduleswitches))
                 and (p=current_asmdata.asmlists[al_procedures]);
      InlineLevel:=0;
      DoNotSplitLine:=false;
      hp:=tai(p.first);
      while assigned(hp) do
       begin
         prefetch(pointer(hp.next)^);
         if not(hp.typ in SkipLineInfo) then
          begin
            current_filepos:=tailineinfo(hp).fileinfo;
            { no line info for inlined code }
            if do_line and (inlinelevel=0) and not DoNotSplitLine then
              WriteSourceLine(hp as tailineinfo);
          end;
         DoNotSplitLine:=false;

         case hp.typ of
           ait_comment :
             Begin
               writer.AsmWrite(asminfo^.comment);
               writer.AsmWritePChar(tai_comment(hp).str);
               writer.AsmLn;
             End;

           ait_regalloc :
             begin
               if (cs_asm_regalloc in current_settings.globalswitches) then
                 writer.AsmWriteLn(asminfo^.comment+'Register '+masm_regname(tai_regalloc(hp).reg)+
                   regallocstr[tai_regalloc(hp).ratype]);
             end;

           ait_tempalloc :
             begin
               if (cs_asm_tempalloc in current_settings.globalswitches) then
                 WriteTempalloc(tai_tempalloc(hp));
             end;

           ait_section :
             begin
               if tai_section(hp).sectype<>sec_none then
                begin
                  if asminfo^.id=as_x86_64_masm then
                    begin
                      if LasTSecType<>sec_none then
                        writer.AsmWriteLn(secnamesml64[LasTSecType]+#9#9'ENDS');
                      writer.AsmLn;
                      writer.AsmWriteLn(secnamesml64[tai_section(hp).sectype]+#9+'SEGMENT')
                    end
                  else
                    begin
                      if LasTSecType<>sec_none then
                        writer.AsmWriteLn('_'+secnames[LasTSecType]+#9#9'ENDS');
                      writer.AsmLn;
                      if (asminfo^.id=as_i386_wasm) then
                        s:='DWORD'
                      else
                        s:=alignstr(tai_section(hp).secalign);
                      writer.AsmWriteLn('_'+secnames[tai_section(hp).sectype]+#9#9+
                                 'SEGMENT'#9+s+' PUBLIC USE32 '''+
                                 secnames[tai_section(hp).sectype]+'''');
                    end;
                end;
               LasTSecType:=tai_section(hp).sectype;
             end;
           ait_align :
             begin
               { CAUSES PROBLEMS WITH THE SEGMENT DEFINITION   }
               { SEGMENT DEFINITION SHOULD MATCH TYPE OF ALIGN }
               { HERE UNDER TASM!                              }
                 if tai_align_abstract(hp).aligntype>1 then
                   writer.AsmWriteLn(#9'ALIGN '+tostr(tai_align_abstract(hp).aligntype));
               end;
           ait_datablock :
             begin
               if tai_datablock(hp).is_global then
                 writer.AsmWriteLn(#9'PUBLIC'#9+tai_datablock(hp).sym.name);
               writer.AsmWriteLn(PadTabs(tai_datablock(hp).sym.name,#0)+'DB'#9+tostr(tai_datablock(hp).size)+' DUP(?)');
             end;
           ait_const:
             begin
               consttype:=tai_const(hp).consttype;
               case consttype of
                 aitconst_uleb128bit,
                 aitconst_sleb128bit,
                 aitconst_128bit,
                 aitconst_64bit,
                 aitconst_32bit,
                 aitconst_16bit,
                 aitconst_8bit,
                 aitconst_rva_symbol,
                 aitconst_secrel32_symbol :
                   begin
                     writer.AsmWrite(ait_const2str[consttype]);
                     l:=0;
		     tokens:=1;
                     repeat
                       if assigned(tai_const(hp).sym) then
                         begin
                           if assigned(tai_const(hp).endsym) then
                             s:=tai_const(hp).endsym.name+'-'+tai_const(hp).sym.name
                           else
                             s:=tai_const(hp).sym.name;
                           if tai_const(hp).value<>0 then
                             s:=s+tostr_with_plus(tai_const(hp).value);
                         end
                       else
                         s:=tostr(tai_const(hp).value);
                       writer.AsmWrite(s);
                       inc(l,length(s));
		       inc(tokens);
                       if (l>line_length) or
                          (tokens>max_tokens) or
                          (hp.next=nil) or
                          (tai(hp.next).typ<>ait_const) or
                          (tai_const(hp.next).consttype<>consttype) then
                         break;
                       hp:=tai(hp.next);
                       writer.AsmWrite(',');
                     until false;
                     { Substract section start for secrel32 type }
                     if consttype=aitconst_secrel32_symbol then
                       writer.AsmWrite(' - $$');
                     writer.AsmLn;
                   end;
                 else
                   internalerror(200704253);
               end;
             end;

           ait_realconst:
             begin
               case tai_realconst(hp).realtyp of
                 aitrealconst_s32bit:
                   begin
                     if (asminfo^.id = as_i386_wasm) and (IsInfinite(tai_realconst(hp).value.s32val)) then
                       begin
                         { Watcom Wasm does not handle Infinity }
                         if Sign(tai_realconst(hp).value.s32val)=PositiveValue then
                           writer.AsmWriteln(#9#9'DB'#9'0,0,80h,7Fh')
                         else
                           writer.AsmWriteln(#9#9'DW'#9'0,0,80h,FFh');
                       end
                     else if (asminfo^.id = as_i386_wasm) and (IsNan(tai_realconst(hp).value.s32val)) then
                       writer.AsmWriteln(#9#9'DB'#9'1,0,80h,7Fh')
                     else
                       writer.AsmWriteLn(#9#9'DD'#9+single2str(tai_realconst(hp).value.s32val));
                   end;
                 aitrealconst_s64bit:
                   begin
                     if (asminfo^.id = as_i386_wasm) and (IsInfinite(tai_realconst(hp).value.s64val)) then
                       begin
                         { Watcom Wasm does not handle Infinity }
                         if Sign(tai_realconst(hp).value.s64val)=PositiveValue then
                           writer.AsmWriteln(#9#9'DW'#9'0,0,0,7FF0h')
                         else
                           writer.AsmWriteln(#9#9'DW'#9'0,0,0,FFF0h');
                       end
                     else if (asminfo^.id = as_i386_wasm) and (IsNan(tai_realconst(hp).value.s64val)) then
                       writer.AsmWriteln(#9#9'DW'#9'0,0,0,0,7FF8h')
                     else
                       writer.AsmWriteLn(#9#9'DQ'#9+double2str(tai_realconst(hp).value.s64val));
                   end;
                 aitrealconst_s80bit:
                   if (asminfo^.id = as_i386_wasm) and (IsInfinite(tai_realconst(hp).value.s80val)) then
                     begin
                       { Watcom Wasm does not handle Infinity }
                       if Sign(tai_realconst(hp).value.s80val)=PositiveValue then
                         writer.AsmWriteln(#9#9'DW'#9'0,0,0,8000h,7FFFh')
                       else
                         writer.AsmWriteln(#9#9'DW'#9'0,0,0,8000h,FFFFh');
                     end
                   else if (asminfo^.id = as_i386_wasm) and (IsNan(tai_realconst(hp).value.s80val)) then
                     writer.AsmWriteln(#9#9'DW'#9'0,0,0,C000h,7FFFh')
                   else
                     writer.AsmWriteLn(#9#9'DT'#9+extended2str(tai_realconst(hp).value.s80val));
                 aitrealconst_s64comp:
                   writer.AsmWriteLn(#9#9'DQ'#9+extended2str(tai_realconst(hp).value.s64compval));
                 else
                   internalerror(2014050604);
               end;
             end;
           ait_string :
             begin
               counter := 0;
               lines := tai_string(hp).len div line_length;
             { separate lines in different parts }
               if tai_string(hp).len > 0 then
                Begin
                  for j := 0 to lines-1 do
                   begin
                     writer.AsmWrite(#9#9'DB'#9);
                     quoted:=false;
                     for i:=counter to counter+line_length-1 do
                        begin
                          { it is an ascii character. }
                          if (ord(tai_string(hp).str[i])>31) and
                             (ord(tai_string(hp).str[i])<128) and
                             (tai_string(hp).str[i]<>'"') then
                              begin
                                if not(quoted) then
                                    begin
                                      if i>counter then
                                        writer.AsmWrite(',');
                                      writer.AsmWrite('"');
                                    end;
                                writer.AsmWrite(tai_string(hp).str[i]);
                                quoted:=true;
                              end { if > 31 and < 128 and ord('"') }
                          else
                              begin
                                  if quoted then
                                      writer.AsmWrite('"');
                                  if i>counter then
                                      writer.AsmWrite(',');
                                  quoted:=false;
                                  writer.AsmWrite(tostr(ord(tai_string(hp).str[i])));
                              end;
                       end; { end for i:=0 to... }
                     if quoted then writer.AsmWrite('"');
                       writer.AsmWrite(target_info.newline);
                     counter := counter+line_length;
                  end; { end for j:=0 ... }
                { do last line of lines }
                if counter<tai_string(hp).len then
                  writer.AsmWrite(#9#9'DB'#9);
                quoted:=false;
                for i:=counter to tai_string(hp).len-1 do
                  begin
                    { it is an ascii character. }
                    if (ord(tai_string(hp).str[i])>31) and
                       (ord(tai_string(hp).str[i])<128) and
                       (tai_string(hp).str[i]<>'"') then
                        begin
                          if not(quoted) then
                              begin
                                if i>counter then
                                  writer.AsmWrite(',');
                                writer.AsmWrite('"');
                              end;
                          writer.AsmWrite(tai_string(hp).str[i]);
                          quoted:=true;
                        end { if > 31 and < 128 and " }
                    else
                        begin
                          if quoted then
                            writer.AsmWrite('"');
                          if i>counter then
                              writer.AsmWrite(',');
                          quoted:=false;
                          writer.AsmWrite(tostr(ord(tai_string(hp).str[i])));
                        end;
                  end; { end for i:=0 to... }
                if quoted then
                  writer.AsmWrite('"');
                end;
               writer.AsmLn;
             end;
           ait_label :
             begin
               if tai_label(hp).labsym.is_used then
                begin
                  writer.AsmWrite(tai_label(hp).labsym.name);
                  if assigned(hp.next) and not(tai(hp.next).typ in
                     [ait_const,ait_realconst,ait_string]) then
                   writer.AsmWriteLn(':')
                  else
                   DoNotSplitLine:=true;
                end;
             end;
           ait_symbol :
             begin
               if tai_symbol(hp).has_value then
                 internalerror(2009090802);
               { wasm is case insensitive, we nned to use only uppercase version 
                 if both a lowercase and an uppercase version are provided }
               if (asminfo^.id = as_i386_wasm) then
                 begin
                   nhp:=tai(hp.next);
                   while assigned(nhp) and (nhp.typ in [ait_function_name,ait_force_line]) do
                     nhp:=tai(nhp.next);
                   if assigned(nhp) and (tai(nhp).typ=ait_symbol) and
                      (lower(tai_symbol(nhp).sym.name)=tai_symbol(hp).sym.name) then
                     begin
                       writer.AsmWriteln(asminfo^.comment+' '+tai_symbol(hp).sym.name+' removed');
                       hp:=tai(nhp);
                     end;
                 end;
               if tai_symbol(hp).is_global then
                 writer.AsmWriteLn(#9'PUBLIC'#9+tai_symbol(hp).sym.name);
               writer.AsmWrite(tai_symbol(hp).sym.name);
               if assigned(hp.next) and not(tai(hp.next).typ in
                  [ait_const,ait_realconst,ait_string]) then
                 writer.AsmWriteLn(':');
             end;
           ait_symbol_end :
             begin
             end;
           ait_instruction :
             begin
               fixed_opcode:=taicpu(hp).FixNonCommutativeOpcodes;
               taicpu(hp).SetOperandOrder(op_intel);
               { Reset }
               suffix:='';
               prefix:= '';
               { We need to explicitely set
                 word prefix to get selectors
                 to be pushed in 2 bytes  PM }
               if (taicpu(hp).opsize=S_W) and
                   (
                    (
                     (fixed_opcode=A_PUSH) or
                     (fixed_opcode=A_POP)
                    ) and
                    (taicpu(hp).oper[0]^.typ=top_reg) and
                    is_segment_reg(taicpu(hp).oper[0]^.reg)
                   ) then
                 writer.AsmWriteln(#9#9'DB'#9'066h');

               { added prefix instructions, must be on same line as opcode }
               if (taicpu(hp).ops = 0) and
                  ((fixed_opcode = A_REP) or
                   (fixed_opcode = A_LOCK) or
                   (fixed_opcode =  A_REPE) or
                   (fixed_opcode =  A_REPNZ) or
                   (fixed_opcode =  A_REPZ) or
                   (fixed_opcode = A_REPNE)) then
                Begin
                  prefix:=std_op2str[fixed_opcode]+#9;
                  { there can be a stab inbetween when the opcode was on
                    a different line in the source code }
                  repeat
                    hp:=tai(hp.next);
                  until (hp=nil) or (hp.typ=ait_instruction);

                  { next instruction ... }
                  fixed_opcode:=taicpu(hp).FixNonCommutativeOpcodes;
                  taicpu(hp).SetOperandOrder(op_intel);

                  { this is theorically impossible... }
                  if hp=nil then
                   begin
                     writer.AsmWriteLn(#9#9+prefix);
                     break;
                   end;
                  { nasm prefers prefix on a line alone
                  writer.AsmWriteln(#9#9+prefix); but not masm PM
                  prefix:=''; }
                  if asminfo^.id in [as_i386_nasmcoff,as_i386_nasmwin32,as_i386_nasmwdosx,
                    as_i386_nasmelf,as_i386_nasmobj,as_i386_nasmbeos,as_i386_nasmhaiku] then
                     begin
                       writer.AsmWriteln(prefix);
                       prefix:='';
                     end;
                end
               else
                prefix:= '';
               if (asminfo^.id = as_i386_wasm) and
                 (taicpu(hp).opsize=S_W) and
                 (fixed_opcode=A_PUSH) and
                 (taicpu(hp).oper[0]^.typ=top_const) then
                 begin
                   writer.AsmWriteln(#9#9'DB 66h,68h ; pushw imm16');
                   writer.AsmWrite(#9#9'DW');
                 end
               else if (asminfo^.id=as_x86_64_masm) and
                 (fixed_opcode=A_MOVQ) then
                 writer.AsmWrite(#9#9'mov')
{$ifdef I386}
               else if (asminfo^.id = as_i386_wasm) and ((fixed_opcode=A_RETD)
                       or (fixed_opcode=A_RETND) or (fixed_opcode=A_RETFD)) then
                 begin
                   { no 'd' suffix for Watcom assembler }
                   case fixed_opcode of
                       A_RETD:
                         writer.AsmWrite(#9#9'ret');
                       A_RETND:
                         writer.AsmWrite(#9#9'retn');
                       A_RETFD:
                         writer.AsmWrite(#9#9'retf');
                   end
                 end
{$endif I386}
               else
                 writer.AsmWrite(#9#9+prefix+std_op2str[fixed_opcode]+cond2str[taicpu(hp).condition]+suffix);
               if taicpu(hp).ops<>0 then
                begin
                  if is_calljmp(fixed_opcode) then
                   begin
                     writer.AsmWrite(#9);
                     WriteOper_jmp(taicpu(hp).oper[0]^,taicpu(hp).opsize);
                   end
                  else
                   begin
                     for i:=0to taicpu(hp).ops-1 do
                      begin
                        if i=0 then
                         writer.AsmWrite(#9)
                        else
                         writer.AsmWrite(',');
                        WriteOper(taicpu(hp).oper[i]^,taicpu(hp).opsize,fixed_opcode,(i=2));
                      end;
                   end;
                end;
               writer.AsmLn;
             end;

           ait_stab,
           ait_force_line,
           ait_function_name : ;

           ait_cutobject :
             begin
               { only reset buffer if nothing has changed }
                 if not writer.ClearIfEmpty then
                  begin
                    if LasTSecType<>sec_none then
                     writer.AsmWriteLn('_'+secnames[LasTSecType]+#9#9'ENDS');
                    writer.AsmLn;
                    writer.AsmWriteLn(#9'END');
                    writer.AsmClose;
                    DoAssemble;
                    writer.AsmCreate(tai_cutobject(hp).place);
                  end;
               { avoid empty files }
                 while assigned(hp.next) and (tai(hp.next).typ in [ait_cutobject,ait_section,ait_comment]) do
                  begin
                    if tai(hp.next).typ=ait_section then
                      lasTSecType:=tai_section(hp.next).sectype;
                    hp:=tai(hp.next);
                  end;
                 if (asminfo^.id = as_i386_wasm) then
                   begin
                     writer.AsmWriteLn(#9'.686p');
                     writer.AsmWriteLn(#9'.xmm');
                   end
                 else
                   writer.AsmWriteLn(#9'.386p');
{$ifdef i8086}
                 writer.AsmWriteLn('DGROUP'#9'GROUP'#9'_BSS,_DATA');
                 writer.AsmWriteLn(#9'ASSUME'#9'CS:_CODE,ES:DGROUP,DS:DGROUP,SS:DGROUP');
{$endif i8086}
                 { I was told that this isn't necesarry because }
                 { the labels generated by FPC are unique (FK)  }
                 { writer.AsmWriteLn(#9'LOCALS '+asminfo^.labelprefix); }
                 { TODO: PARA is incorrect, must use actual section align }
                 if lasTSectype<>sec_none then
                    writer.AsmWriteLn('_'+secnames[lasTSectype]+#9#9+
                               'SEGMENT'#9'PARA PUBLIC USE32 '''+
                               secnames[lasTSectype]+'''');
                 writer.MarkEmpty;
               end;
           ait_marker :
             begin
               if tai_marker(hp).kind=mark_NoLineInfoStart then
                 inc(InlineLevel)
               else if tai_marker(hp).kind=mark_NoLineInfoEnd then
                 dec(InlineLevel);
             end;

           ait_directive :
             begin
               case tai_directive(hp).directive of
                 asd_nasm_import :
                   begin
                     writer.AsmWrite('import ');
                     writer.AsmWrite(tai_directive(hp).name);
                     writer.AsmLn;
                   end;
                 asd_extern :
                   begin
                     writer.AsmWrite('EXTRN ');
                     writer.AsmWrite(tai_directive(hp).name);
                     writer.AsmLn;
                   end;
                 asd_cpu :
                   begin
                     if (asminfo^.id = as_i386_wasm) then
                       begin
                         {writer.AsmWrite('.');}
                         for cpu:=low(tcputype) to high(tcputype) do
                           begin
                             if tai_directive(hp).name=CPUTypeStr[CPU] then
                               begin
                                 { writer.AsmWriteLn(wasm_cpu_name[cpu]); }
                                 break;
                               end;
                           end;
                       end
                     else
                       begin
                         { TODO: implement this properly for TASM/MASM/WASM (.686p, etc.) }
                         writer.AsmWrite(asminfo^.comment+' CPU ');
                         writer.AsmWrite(tai_directive(hp).name);
                         writer.AsmLn;
                       end;
                   end
                 else
                   internalerror(200509192);
               end;
             end;
           ait_seh_directive :
             { Ignore for now };
           else
            internalerror(10000);
         end;
         hp:=tai(hp.next);
       end;
    end;


    procedure tx86intelassembler.WriteExternals;
      var
        sym : TAsmSymbol;
        i   : longint;
      begin
        for i:=0 to current_asmdata.AsmSymbolDict.Count-1 do
          begin
            sym:=TAsmSymbol(current_asmdata.AsmSymbolDict[i]);
            if sym.bind in [AB_EXTERNAL,AB_EXTERNAL_INDIRECT] then
              begin
                case asminfo^.id of
                  as_i386_masm,
                  as_i386_wasm :
                    writer.AsmWriteln(#9'EXTRN'#9+sym.name+': NEAR');
                  as_x86_64_masm :
                    writer.AsmWriteln(#9'EXTRN'#9+sym.name+': PROC');
                  else
                    writer.AsmWriteln(#9'EXTRN'#9+sym.name);
                end;
              end;
          end;
      end;


    function tx86intelassembler.DoAssemble : boolean;
    var
      masmobjfn : string;
    begin
      DoAssemble:=Inherited DoAssemble;
      { masm does not seem to recognize specific extensions and uses .obj allways PM }
      if (asminfo^.id in [as_i386_masm,as_i386_wasm]) then
        begin
          masmobjfn:=ChangeFileExt(objfilename,'.obj');
          if not(cs_asm_extern in current_settings.globalswitches) then
            begin
              if Not FileExists(objfilename) and
                 FileExists(masmobjfn) then
                RenameFile(masmobjfn,objfilename);
            end
          else
            AsmRes.AddAsmCommand('mv',masmobjfn+' '+objfilename,objfilename);
        end;
    end;


    procedure tx86IntelAssembler.WriteAsmList;
    var
      hal : tasmlisttype;
    begin
{$ifdef EXTDEBUG}
      if current_module.mainsource<>'' then
       comment(v_info,'Start writing intel-styled assembler output for '+current_module.mainsource);
{$endif}
      if asminfo^.id<>as_x86_64_masm then
        begin
          if (asminfo^.id = as_i386_wasm) then
            begin
              writer.AsmWriteLn(#9'.686p');
              writer.AsmWriteLn(#9'.xmm');
            end
          else
            writer.AsmWriteLn(#9'.386p');
          { masm 6.11 does not seem to like LOCALS PM }
          if (asminfo^.id = as_i386_tasm) then
            begin
              writer.AsmWriteLn(#9'LOCALS '+asminfo^.labelprefix);
            end;
{$ifdef i8086}
          writer.AsmWriteLn('DGROUP'#9'GROUP'#9'_BSS,_DATA');
          writer.AsmWriteLn(#9'ASSUME'#9'CS:_CODE,ES:DGROUP,DS:DGROUP,SS:DGROUP');
{$endif i8086}
          writer.AsmLn;
        end;

      WriteExternals;

      for hal:=low(TasmlistType) to high(TasmlistType) do
        begin
          writer.AsmWriteLn(asminfo^.comment+'Begin asmlist '+AsmListTypeStr[hal]);
          writetree(current_asmdata.asmlists[hal]);
          writer.AsmWriteLn(asminfo^.comment+'End asmlist '+AsmListTypeStr[hal]);
        end;

      { better do this at end of WriteTree, but then there comes a trouble with
        al_const which does not have leading ait_section and thus goes out of segment }

      if LastSecType <> sec_none then
        begin
          if asminfo^.id=as_x86_64_masm then
            writer.AsmWriteLn(secnamesml64[LasTSecType]+#9#9'ENDS')
          else
            writer.AsmWriteLn('_'+secnames[LasTSecType]+#9#9'ENDS');
        end;
      LastSecType := sec_none;

      writer.AsmWriteLn(#9'END');
      writer.AsmLn;

{$ifdef EXTDEBUG}
      if current_module.mainsource<>'' then
       comment(v_info,'Done writing intel-styled assembler output for '+current_module.mainsource);
{$endif EXTDEBUG}
   end;


{*****************************************************************************
                                  Initialize
*****************************************************************************}

    const
{$ifdef i386}
       as_i386_tasm_info : tasminfo =
          (
            id           : as_i386_tasm;
            idtxt  : 'TASM';
            asmbin : 'tasm';
            asmcmd : '/m2 /ml $EXTRAOPT $ASM $OBJ';
            supported_targets : [system_i386_GO32V2,system_i386_Win32,system_i386_wdosx,system_i386_watcom,system_i386_wince];
            flags : [af_needar,af_labelprefix_only_inside_procedure];
            labelprefix : '@@';
            comment : '; ';
            dollarsign: '$';
          );

       as_i386_masm_info : tasminfo =
          (
            id           : as_i386_masm;
            idtxt  : 'MASM';
            asmbin : 'masm';
            asmcmd : '/c /Cp $EXTRAOPT $ASM /Fo$OBJ';
            supported_targets : [system_i386_GO32V2,system_i386_Win32,system_i386_wdosx,system_i386_watcom,system_i386_wince];
            flags : [af_needar];
            labelprefix : '@@';
            comment : '; ';
            dollarsign: '$';
          );

       as_i386_wasm_info : tasminfo =
          (
            id     : as_i386_wasm;
            idtxt  : 'WASM';
            asmbin : 'wasm';
            asmcmd : '$ASM $EXTRAOPT -6s -fp6 -ms -zq -Fo=$OBJ';
            supported_targets : [system_i386_watcom];
            flags : [af_needar];
            labelprefix : '@@';
            comment : '; ';
            dollarsign: '$';
          );
{$endif i386}
{$ifdef x86_64}
       as_x86_64_masm_info : tasminfo =
          (
            id     : as_x86_64_masm;
            idtxt  : 'MASM';
            asmbin : 'ml64';
            asmcmd : '/c /Cp $EXTRAOPT $ASM /Fo$OBJ';
            supported_targets : [system_x86_64_win64];
            flags : [af_needar];
            labelprefix : '@@';
            comment : '; ';
            dollarsign: '$';
          );
{$endif x86_64}

initialization
{$ifdef x86_64}
  RegisterAssembler(as_x86_64_masm_info,tx86IntelAssembler);
{$endif x86_64}
{$ifdef i386}
  RegisterAssembler(as_i386_tasm_info,tx86IntelAssembler);
  RegisterAssembler(as_i386_masm_info,tx86IntelAssembler);
  RegisterAssembler(as_i386_wasm_info,tx86IntelAssembler);
{$endif i386}
end.
