fpc/compiler/x86/cgx86.pas

{
    Copyright (c) 1998-2005 by Florian Klaempfl

    This unit implements the common parts of the code generator for the i386 and the x86-64.

    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 the common parts of the code generator for the i386 and the x86-64.
}
unit cgx86;

{$i fpcdefs.inc}

  interface

    uses
       globtype,
       cgbase,cgutils,cgobj,
       aasmbase,aasmtai,aasmdata,aasmcpu,
       cpubase,cpuinfo,rgobj,rgx86,rgcpu,
       symconst,symtype,symdef;

    type
      tcgx86 = class(tcg)
        rgfpu   : Trgx86fpu;
        procedure done_register_allocators;override;

        function getfpuregister(list:TAsmList;size:Tcgsize):Tregister;override;
        function getmmxregister(list:TAsmList):Tregister;
        function getmmregister(list:TAsmList;size:Tcgsize):Tregister;override;

        procedure getcpuregister(list:TAsmList;r:Tregister);override;
        procedure ungetcpuregister(list:TAsmList;r:Tregister);override;
        procedure alloccpuregisters(list:TAsmList;rt:Tregistertype;const r:Tcpuregisterset);override;
        procedure dealloccpuregisters(list:TAsmList;rt:Tregistertype;const r:Tcpuregisterset);override;
        function  uses_registers(rt:Tregistertype):boolean;override;
        procedure add_reg_instruction(instr:Tai;r:tregister);override;
        procedure dec_fpu_stack;
        procedure inc_fpu_stack;

        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_call_name_static(list : TAsmList;const s : string);override;

        procedure a_op_const_reg(list : TAsmList; Op: TOpCG; size: TCGSize; a: tcgint; reg: TRegister); override;
        procedure a_op_const_ref(list : TAsmList; Op: TOpCG; size: TCGSize; a: tcgint; const ref: TReference); override;
        procedure a_op_reg_reg(list : TAsmList; Op: TOpCG; size: TCGSize; src, dst: TRegister); override;
        procedure a_op_ref_reg(list : TAsmList; Op: TOpCG; size: TCGSize; const ref: TReference; reg: TRegister); override;
        procedure a_op_reg_ref(list : TAsmList; Op: TOpCG; size: TCGSize;reg: TRegister; const ref: TReference); override;

        { move instructions }
        procedure a_load_const_reg(list : TAsmList; tosize: tcgsize; a : tcgint;reg : tregister);override;
        procedure a_load_const_ref(list : TAsmList; tosize: tcgsize; a : tcgint;const ref : treference);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;
        procedure a_loadaddr_ref_reg(list : TAsmList;const ref : treference;r : tregister);override;

        { bit scan instructions }
        procedure a_bit_scan_reg_reg(list: TAsmList; reverse: boolean; size: TCGSize; src, dst: TRegister); override;

        { fpu move instructions }
        procedure a_loadfpu_reg_reg(list: TAsmList; fromsize, tosize: tcgsize; reg1, reg2: tregister); override;
        procedure a_loadfpu_ref_reg(list: TAsmList; fromsize, tosize: tcgsize; const ref: treference; reg: tregister); override;
        procedure a_loadfpu_reg_ref(list: TAsmList; fromsize, tosize: tcgsize; reg: tregister; const ref: treference); override;

        { vector register move instructions }
        procedure a_loadmm_reg_reg(list: TAsmList; fromsize, tosize : tcgsize;reg1, reg2: tregister;shuffle : pmmshuffle); override;
        procedure a_loadmm_ref_reg(list: TAsmList; fromsize, tosize : tcgsize;const ref: treference; reg: tregister;shuffle : pmmshuffle); override;
        procedure a_loadmm_reg_ref(list: TAsmList; fromsize, tosize : tcgsize;reg: tregister; const ref: treference;shuffle : pmmshuffle); override;
        procedure a_opmm_ref_reg(list: TAsmList; Op: TOpCG; size : tcgsize;const ref: treference; reg: tregister;shuffle : pmmshuffle); override;
        procedure a_opmm_reg_reg(list: TAsmList; Op: TOpCG; size : tcgsize;src,dst: tregister;shuffle : pmmshuffle);override;

        {  comparison operations }
        procedure a_cmp_const_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;a : tcgint;reg : tregister;
          l : tasmlabel);override;
        procedure a_cmp_const_ref_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;a : tcgint;const ref : treference;
          l : tasmlabel);override;
        procedure a_cmp_reg_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;reg1,reg2 : tregister;l : tasmlabel); override;
        procedure a_cmp_ref_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;const ref: treference; reg : tregister; l : tasmlabel); override;
        procedure a_cmp_reg_ref_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;reg : tregister; const ref: treference; 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_flags2ref(list: TAsmList; size: TCgSize; const f: tresflags; const ref: TReference); override;

        procedure g_concatcopy(list : TAsmList;const source,dest : treference;len : tcgint);override;

        { entry/exit code helpers }
        procedure g_profilecode(list : TAsmList);override;
        procedure g_stackpointer_alloc(list : TAsmList;localsize : longint);override;
        procedure g_proc_entry(list : TAsmList;localsize : longint;nostackframe:boolean);override;

        procedure g_overflowcheck(list: TAsmList; const l:tlocation;def:tdef);override;

        procedure g_external_wrapper(list: TAsmList; procdef: tprocdef; const externalname: string); override;

        procedure make_simple_ref(list:TAsmList;var ref: treference);
      protected
        procedure a_jmp_cond(list : TAsmList;cond : TOpCmp;l: tasmlabel);
        procedure check_register_size(size:tcgsize;reg:tregister);

        procedure opmm_loc_reg(list: TAsmList; Op: TOpCG; size : tcgsize;loc : tlocation;dst: tregister; shuffle : pmmshuffle);

        function get_darwin_call_stub(const s: string; weak: boolean): tasmsymbol;
      private
        procedure sizes2load(s1,s2 : tcgsize;var op: tasmop; var s3: topsize);

        procedure floatload(list: TAsmList; t : tcgsize;const ref : treference);
        procedure floatstore(list: TAsmList; t : tcgsize;const ref : treference);
        procedure floatloadops(t : tcgsize;var op : tasmop;var s : topsize);
        procedure floatstoreops(t : tcgsize;var op : tasmop;var s : topsize);

      end;

   const
{$ifdef x86_64}
      TCGSize2OpSize: Array[tcgsize] of topsize =
        (S_NO,S_B,S_W,S_L,S_Q,S_T,S_B,S_W,S_L,S_Q,S_Q,
         S_FS,S_FL,S_FX,S_IQ,S_FXX,
         S_NO,S_NO,S_NO,S_MD,S_T,
         S_NO,S_NO,S_NO,S_NO,S_T);
{$else x86_64}
      TCGSize2OpSize: Array[tcgsize] of topsize =
        (S_NO,S_B,S_W,S_L,S_L,S_T,S_B,S_W,S_L,S_L,S_L,
         S_FS,S_FL,S_FX,S_IQ,S_FXX,
         S_NO,S_NO,S_NO,S_MD,S_T,
         S_NO,S_NO,S_NO,S_NO,S_T);
{$endif x86_64}

{$ifndef NOTARGETWIN}
      winstackpagesize = 4096;
{$endif NOTARGETWIN}

  implementation

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

    const
      TOpCG2AsmOp: Array[topcg] of TAsmOp = (A_NONE,A_MOV,A_ADD,A_AND,A_DIV,
                            A_IDIV,A_IMUL,A_MUL,A_NEG,A_NOT,A_OR,
                            A_SAR,A_SHL,A_SHR,A_SUB,A_XOR,A_ROL,A_ROR);

      TOpCmp2AsmCond: Array[topcmp] of TAsmCond = (C_NONE,
          C_E,C_G,C_L,C_GE,C_LE,C_NE,C_BE,C_B,C_AE,C_A);

    procedure Tcgx86.done_register_allocators;
      begin
        rg[R_INTREGISTER].free;
        rg[R_MMREGISTER].free;
        rg[R_MMXREGISTER].free;
        rgfpu.free;
        inherited done_register_allocators;
      end;


    function Tcgx86.getfpuregister(list:TAsmList;size:Tcgsize):Tregister;
      begin
        result:=rgfpu.getregisterfpu(list);
      end;


    function Tcgx86.getmmxregister(list:TAsmList):Tregister;
      begin
        if not assigned(rg[R_MMXREGISTER]) then
          internalerror(2003121214);
        result:=rg[R_MMXREGISTER].getregister(list,R_SUBNONE);
      end;


    function Tcgx86.getmmregister(list:TAsmList;size:Tcgsize):Tregister;
      begin
        if not assigned(rg[R_MMREGISTER]) then
          internalerror(2003121234);
        case size of
          OS_F64:
            result:=rg[R_MMREGISTER].getregister(list,R_SUBMMD);
          OS_F32:
            result:=rg[R_MMREGISTER].getregister(list,R_SUBMMS);
          OS_M64,
          OS_M128:
            result:=rg[R_MMREGISTER].getregister(list,R_SUBMMWHOLE);
          else
            internalerror(200506041);
        end;
      end;


    procedure Tcgx86.getcpuregister(list:TAsmList;r:Tregister);
      begin
        if getregtype(r)=R_FPUREGISTER then
          internalerror(2003121210)
        else
          inherited getcpuregister(list,r);
      end;


    procedure tcgx86.ungetcpuregister(list:TAsmList;r:Tregister);
      begin
        if getregtype(r)=R_FPUREGISTER then
          rgfpu.ungetregisterfpu(list,r)
        else
          inherited ungetcpuregister(list,r);
      end;


    procedure Tcgx86.alloccpuregisters(list:TAsmList;rt:Tregistertype;const r:Tcpuregisterset);
      begin
        if rt<>R_FPUREGISTER then
          inherited alloccpuregisters(list,rt,r);
      end;


    procedure Tcgx86.dealloccpuregisters(list:TAsmList;rt:Tregistertype;const r:Tcpuregisterset);
      begin
        if rt<>R_FPUREGISTER then
          inherited dealloccpuregisters(list,rt,r);
      end;


    function  Tcgx86.uses_registers(rt:Tregistertype):boolean;
      begin
        if rt=R_FPUREGISTER then
          result:=false
        else
          result:=inherited uses_registers(rt);
      end;


    procedure tcgx86.add_reg_instruction(instr:Tai;r:tregister);
      begin
        if getregtype(r)<>R_FPUREGISTER then
          inherited add_reg_instruction(instr,r);
      end;


    procedure tcgx86.dec_fpu_stack;
      begin
        if rgfpu.fpuvaroffset<=0 then
          internalerror(200604201);
        dec(rgfpu.fpuvaroffset);
      end;


    procedure tcgx86.inc_fpu_stack;
      begin
        if rgfpu.fpuvaroffset>=7 then
          internalerror(2012062901);
        inc(rgfpu.fpuvaroffset);
      end;


{****************************************************************************
                       This is private property, keep out! :)
****************************************************************************}

    procedure tcgx86.sizes2load(s1,s2 : tcgsize; var op: tasmop; var s3: topsize);

       begin
         { ensure to have always valid sizes }
         if s1=OS_NO then
           s1:=s2;
         if s2=OS_NO then
           s2:=s1;
         case s2 of
           OS_8,OS_S8 :
             if S1 in [OS_8,OS_S8] then
               s3 := S_B
             else
               internalerror(200109221);
           OS_16,OS_S16:
             case s1 of
               OS_8,OS_S8:
                 s3 := S_BW;
               OS_16,OS_S16:
                 s3 := S_W;
               else
                 internalerror(200109222);
             end;
           OS_32,OS_S32:
             case s1 of
               OS_8,OS_S8:
                 s3 := S_BL;
               OS_16,OS_S16:
                 s3 := S_WL;
               OS_32,OS_S32:
                 s3 := S_L;
               else
                 internalerror(200109223);
             end;
{$ifdef x86_64}
           OS_64,OS_S64:
             case s1 of
               OS_8:
                 s3 := S_BL;
               OS_S8:
                 s3 := S_BQ;
               OS_16:
                 s3 := S_WL;
               OS_S16:
                 s3 := S_WQ;
               OS_32:
                 s3 := S_L;
               OS_S32:
                 s3 := S_LQ;
               OS_64,OS_S64:
                 s3 := S_Q;
               else
                 internalerror(200304302);
             end;
{$endif x86_64}
           else
             internalerror(200109227);
         end;
         if s3 in [S_B,S_W,S_L,S_Q] then
           op := A_MOV
         else if s1 in [OS_8,OS_16,OS_32,OS_64] then
           op := A_MOVZX
         else
{$ifdef x86_64}
           if s3 in [S_LQ] then
             op := A_MOVSXD
         else
{$endif x86_64}
           op := A_MOVSX;
       end;


    procedure tcgx86.make_simple_ref(list:TAsmList;var ref: treference);
      var
        hreg : tregister;
        href : treference;
{$ifndef x86_64}
        add_hreg: boolean;
{$endif not  x86_64}
      begin
        { make_simple_ref() may have already been called earlier, and in that
          case make sure we don't perform the PIC-simplifications twice }
        if (ref.refaddr in [addr_pic,addr_pic_no_got]) then
          exit;

{$ifdef x86_64}
        { Only 32bit is allowed }
        if ((ref.offset<low(longint)) or (ref.offset>high(longint))) then
          begin
            { Load constant value to register }
            hreg:=GetAddressRegister(list);
            list.concat(taicpu.op_const_reg(A_MOV,S_Q,ref.offset,hreg));
            ref.offset:=0;
            {if assigned(ref.symbol) then
              begin
                list.concat(taicpu.op_sym_ofs_reg(A_ADD,S_Q,ref.symbol,0,hreg));
                ref.symbol:=nil;
              end;}
            { Add register to reference }
            if ref.index=NR_NO then
              ref.index:=hreg
            else
              begin
                { don't use add, as the flags may contain a value }
                reference_reset_base(href,ref.base,0,8);
                href.index:=hreg;
                if ref.scalefactor<>0 then
                  begin
                    reference_reset_base(href,ref.base,0,8);
                    href.index:=hreg;
                    list.concat(taicpu.op_ref_reg(A_LEA,S_Q,href,hreg));
                    ref.base:=hreg;
                  end
                else
                  begin
                    reference_reset_base(href,ref.index,0,8);
                    href.index:=hreg;
                    list.concat(taicpu.op_reg_reg(A_ADD,S_Q,ref.index,hreg));
                    ref.index:=hreg;
                  end;
               end;
          end;

        if assigned(ref.symbol) then
          begin
            if cs_create_pic in current_settings.moduleswitches then
              begin
                { Local symbols must not be accessed via the GOT }
                if (ref.symbol.bind=AB_LOCAL) then
                  begin
                    { unfortunately, RIP-based addresses don't support an index }
                    if (ref.base<>NR_NO) or
                       (ref.index<>NR_NO) then
                      begin
                        reference_reset_symbol(href,ref.symbol,0,ref.alignment);
                        hreg:=getaddressregister(list);
                        href.refaddr:=addr_pic_no_got;
                        href.base:=NR_RIP;
                        list.concat(taicpu.op_ref_reg(A_LEA,S_Q,href,hreg));
                        ref.symbol:=nil;
                      end
                    else
                      begin
                        ref.refaddr:=addr_pic_no_got;
                        hreg:=NR_NO;
                        ref.base:=NR_RIP;
                      end;
                  end
                else
                  begin
                    reference_reset_symbol(href,ref.symbol,0,ref.alignment);
                    hreg:=getaddressregister(list);
                    href.refaddr:=addr_pic;
                    href.base:=NR_RIP;
                    list.concat(taicpu.op_ref_reg(A_MOV,S_Q,href,hreg));

                    ref.symbol:=nil;
                  end;

                if ref.base=NR_NO then
                  ref.base:=hreg
                else if ref.index=NR_NO then
                  begin
                    ref.index:=hreg;
                    ref.scalefactor:=1;
                  end
                else
                  begin
                    { don't use add, as the flags may contain a value }
                    reference_reset_base(href,ref.base,0,8);
                    href.index:=hreg;
                    list.concat(taicpu.op_ref_reg(A_LEA,S_Q,href,hreg));
                    ref.base:=hreg;
                  end;
              end
            else
              { Always use RIP relative symbol addressing for Windows and Darwin targets. }
              if (target_info.system in (systems_all_windows+[system_x86_64_darwin])) and (ref.base<>NR_RIP) then
                begin
                  if (ref.refaddr=addr_no) and (ref.base=NR_NO) and (ref.index=NR_NO) then
                    begin
                      { Set RIP relative addressing for simple symbol references }
                      ref.base:=NR_RIP;
                      ref.refaddr:=addr_pic_no_got
                    end
                  else
                    begin
                      { Use temp register to load calculated 64-bit symbol address for complex references }
                      reference_reset_symbol(href,ref.symbol,0,sizeof(pint));
                      href.base:=NR_RIP;
                      href.refaddr:=addr_pic_no_got;
                      hreg:=GetAddressRegister(list);
                      list.concat(taicpu.op_ref_reg(A_LEA,S_Q,href,hreg));
                      ref.symbol:=nil;
                      if ref.base=NR_NO then
                        ref.base:=hreg
                      else if ref.index=NR_NO then
                        begin
                          ref.index:=hreg;
                          ref.scalefactor:=0;
                        end
                      else
                        begin
                          { don't use add, as the flags may contain a value }
                          reference_reset_base(href,ref.base,0,8);
                          href.index:=hreg;
                          list.concat(taicpu.op_ref_reg(A_LEA,S_Q,href,hreg));
                          ref.base:=hreg;
                        end;
                    end;

                end;
          end;
{$else x86_64}
        add_hreg:=false;
        if (target_info.system in [system_i386_darwin,system_i386_iphonesim]) then
          begin
            if assigned(ref.symbol) and
               not(assigned(ref.relsymbol)) and
               ((ref.symbol.bind in [AB_EXTERNAL,AB_WEAK_EXTERNAL]) or
                (cs_create_pic in current_settings.moduleswitches)) then
             begin
               if (ref.symbol.bind in [AB_EXTERNAL,AB_WEAK_EXTERNAL]) or
                  ((cs_create_pic in current_settings.moduleswitches) and
                   (ref.symbol.bind in [AB_COMMON,AB_GLOBAL,AB_PRIVATE_EXTERN])) then
                 begin
                   hreg:=g_indirect_sym_load(list,ref.symbol.name,asmsym2indsymflags(ref.symbol));
                   ref.symbol:=nil;
                 end
               else
                 begin
                   include(current_procinfo.flags,pi_needs_got);
                   hreg:=current_procinfo.got;
                   ref.relsymbol:=current_procinfo.CurrGOTLabel;
                 end;
               add_hreg:=true
             end
          end
        else if (cs_create_pic in current_settings.moduleswitches) and
           assigned(ref.symbol) then
          begin
            reference_reset_symbol(href,ref.symbol,0,sizeof(pint));
            href.base:=current_procinfo.got;
            href.refaddr:=addr_pic;
            include(current_procinfo.flags,pi_needs_got);
            hreg:=cg.getaddressregister(list);
            list.concat(taicpu.op_ref_reg(A_MOV,S_L,href,hreg));
            ref.symbol:=nil;
            add_hreg:=true;
          end;

        if add_hreg then
          begin
            if ref.base=NR_NO then
              ref.base:=hreg
            else if ref.index=NR_NO then
              begin
                ref.index:=hreg;
                ref.scalefactor:=1;
              end
            else
              begin
                { don't use add, as the flags may contain a value }
                reference_reset_base(href,ref.base,0,8);
                href.index:=hreg;
                list.concat(taicpu.op_ref_reg(A_LEA,S_L,href,hreg));
                ref.base:=hreg;
              end;
          end;
{$endif x86_64}
      end;


    procedure tcgx86.floatloadops(t : tcgsize;var op : tasmop;var s : topsize);
      begin
         case t of
            OS_F32 :
              begin
                 op:=A_FLD;
                 s:=S_FS;
              end;
            OS_F64 :
              begin
                 op:=A_FLD;
                 s:=S_FL;
              end;
            OS_F80 :
              begin
                 op:=A_FLD;
                 s:=S_FX;
              end;
            OS_C64 :
              begin
                 op:=A_FILD;
                 s:=S_IQ;
              end;
            else
              internalerror(200204043);
         end;
      end;


    procedure tcgx86.floatload(list: TAsmList; t : tcgsize;const ref : treference);

      var
         op : tasmop;
         s : topsize;
         tmpref : treference;
      begin
         tmpref:=ref;
         make_simple_ref(list,tmpref);
         floatloadops(t,op,s);
         list.concat(Taicpu.Op_ref(op,s,tmpref));
         inc_fpu_stack;
      end;


    procedure tcgx86.floatstoreops(t : tcgsize;var op : tasmop;var s : topsize);

      begin
         case t of
            OS_F32 :
              begin
                 op:=A_FSTP;
                 s:=S_FS;
              end;
            OS_F64 :
              begin
                 op:=A_FSTP;
                 s:=S_FL;
              end;
            OS_F80 :
              begin
                  op:=A_FSTP;
                  s:=S_FX;
               end;
            OS_C64 :
               begin
                  op:=A_FISTP;
                  s:=S_IQ;
               end;
            else
               internalerror(200204042);
         end;
      end;


    procedure tcgx86.floatstore(list: TAsmList; t : tcgsize;const ref : treference);

      var
         op : tasmop;
         s : topsize;
         tmpref : treference;
      begin
         tmpref:=ref;
         make_simple_ref(list,tmpref);
         floatstoreops(t,op,s);
         list.concat(Taicpu.Op_ref(op,s,tmpref));
         { storing non extended floats can cause a floating point overflow }
         if (t<>OS_F80) and
            (cs_fpu_fwait in current_settings.localswitches) then
           list.concat(Taicpu.Op_none(A_FWAIT,S_NO));
         dec_fpu_stack;
      end;


    procedure tcgx86.check_register_size(size:tcgsize;reg:tregister);
      begin
        if TCGSize2OpSize[size]<>TCGSize2OpSize[reg_cgsize(reg)] then
          internalerror(200306031);
      end;


{****************************************************************************
                              Assembler code
****************************************************************************}

    procedure tcgx86.a_jmp_name(list : TAsmList;const s : string);
      var
        r: treference;
      begin
        if (target_info.system <> system_i386_darwin) then
          list.concat(taicpu.op_sym(A_JMP,S_NO,current_asmdata.RefAsmSymbol(s)))
        else
          begin
            reference_reset_symbol(r,get_darwin_call_stub(s,false),0,sizeof(pint));
            r.refaddr:=addr_full;
            list.concat(taicpu.op_ref(A_JMP,S_NO,r));
          end;
      end;


    procedure tcgx86.a_jmp_always(list : TAsmList;l: tasmlabel);
      begin
        a_jmp_cond(list, OC_NONE, l);
      end;


    function tcgx86.get_darwin_call_stub(const s: string; weak: boolean): tasmsymbol;
      var
        stubname: string;
      begin
        stubname := 'L'+s+'$stub';
        result := current_asmdata.getasmsymbol(stubname);
        if assigned(result) then
          exit;

        if current_asmdata.asmlists[al_imports]=nil then
          current_asmdata.asmlists[al_imports]:=TAsmList.create;

        new_section(current_asmdata.asmlists[al_imports],sec_stub,'',0);
        result := current_asmdata.RefAsmSymbol(stubname);
        current_asmdata.asmlists[al_imports].concat(Tai_symbol.Create(result,0));
        { register as a weak symbol if necessary }
        if weak then
          current_asmdata.weakrefasmsymbol(s);
        current_asmdata.asmlists[al_imports].concat(tai_directive.create(asd_indirect_symbol,s));
        current_asmdata.asmlists[al_imports].concat(taicpu.op_none(A_HLT));
        current_asmdata.asmlists[al_imports].concat(taicpu.op_none(A_HLT));
        current_asmdata.asmlists[al_imports].concat(taicpu.op_none(A_HLT));
        current_asmdata.asmlists[al_imports].concat(taicpu.op_none(A_HLT));
        current_asmdata.asmlists[al_imports].concat(taicpu.op_none(A_HLT));
      end;


    procedure tcgx86.a_call_name(list : TAsmList;const s : string; weak: boolean);
      var
        sym : tasmsymbol;
        r : treference;
      begin

        if (target_info.system <> system_i386_darwin) then
          begin
            if not(weak) then
              sym:=current_asmdata.RefAsmSymbol(s)
            else
              sym:=current_asmdata.WeakRefAsmSymbol(s);
            reference_reset_symbol(r,sym,0,sizeof(pint));
            if (cs_create_pic in current_settings.moduleswitches) and
               { darwin's assembler doesn't want @PLT after call symbols }
               not(target_info.system in [system_x86_64_darwin,system_i386_iphonesim]) then
              begin
{$ifdef i386}
                include(current_procinfo.flags,pi_needs_got);
{$endif i386}
                r.refaddr:=addr_pic
              end
            else
              r.refaddr:=addr_full;
          end
        else
          begin
            reference_reset_symbol(r,get_darwin_call_stub(s,weak),0,sizeof(pint));
            r.refaddr:=addr_full;
          end;
        list.concat(taicpu.op_ref(A_CALL,S_NO,r));
      end;


    procedure tcgx86.a_call_name_static(list : TAsmList;const s : string);
      var
        sym : tasmsymbol;
        r : treference;
      begin
        sym:=current_asmdata.RefAsmSymbol(s);
        reference_reset_symbol(r,sym,0,sizeof(pint));
        r.refaddr:=addr_full;
        list.concat(taicpu.op_ref(A_CALL,S_NO,r));
      end;


    procedure tcgx86.a_call_reg(list : TAsmList;reg : tregister);
      begin
        list.concat(taicpu.op_reg(A_CALL,S_NO,reg));
      end;


    procedure tcgx86.a_call_ref(list : TAsmList;ref : treference);
      begin
        list.concat(taicpu.op_ref(A_CALL,S_NO,ref));
      end;


{********************** load instructions ********************}

    procedure tcgx86.a_load_const_reg(list : TAsmList; tosize: TCGSize; a : tcgint; reg : TRegister);

      begin
        check_register_size(tosize,reg);
        { the optimizer will change it to "xor reg,reg" when loading zero, }
        { no need to do it here too (JM)                                   }
        list.concat(taicpu.op_const_reg(A_MOV,TCGSize2OpSize[tosize],a,reg))
      end;


    procedure tcgx86.a_load_const_ref(list : TAsmList; tosize: tcgsize; a : tcgint;const ref : treference);
      var
        tmpref : treference;
      begin
        tmpref:=ref;
        make_simple_ref(list,tmpref);
{$ifdef x86_64}
        { x86_64 only supports signed 32 bits constants directly }
        if (tosize in [OS_S64,OS_64]) and
           ((a<low(longint)) or (a>high(longint))) then
          begin
            a_load_const_ref(list,OS_32,longint(a and $ffffffff),tmpref);
            inc(tmpref.offset,4);
            a_load_const_ref(list,OS_32,longint(a shr 32),tmpref);
          end
        else
{$endif x86_64}
          list.concat(taicpu.op_const_ref(A_MOV,TCGSize2OpSize[tosize],a,tmpref));
      end;


    procedure tcgx86.a_load_reg_ref(list : TAsmList; fromsize,tosize: TCGSize; reg : tregister;const ref : treference);
      var
        op: tasmop;
        s: topsize;
        tmpsize : tcgsize;
        tmpreg  : tregister;
        tmpref  : treference;
      begin
        tmpref:=ref;
        make_simple_ref(list,tmpref);
        check_register_size(fromsize,reg);
        sizes2load(fromsize,tosize,op,s);
        case s of
{$ifdef x86_64}
          S_BQ,S_WQ,S_LQ,
{$endif x86_64}
          S_BW,S_BL,S_WL :
            begin
              tmpreg:=getintregister(list,tosize);
{$ifdef x86_64}
              { zero extensions to 64 bit on the x86_64 are simply done by writting to the lower 32 bit
                which clears the upper 64 bit too, so it could be that s is S_L while the reg is
                64 bit (FK) }
              if s in [S_BL,S_WL,S_L] then
                begin
                  tmpreg:=makeregsize(list,tmpreg,OS_32);
                  tmpsize:=OS_32;
                end
              else
{$endif x86_64}
                tmpsize:=tosize;
              list.concat(taicpu.op_reg_reg(op,s,reg,tmpreg));
              a_load_reg_ref(list,tmpsize,tosize,tmpreg,tmpref);
            end;
        else
          list.concat(taicpu.op_reg_ref(op,s,reg,tmpref));
        end;
      end;


    procedure tcgx86.a_load_ref_reg(list : TAsmList;fromsize,tosize : tcgsize;const ref: treference;reg : tregister);
      var
        op: tasmop;
        s: topsize;
        tmpref  : treference;
      begin
        tmpref:=ref;
        make_simple_ref(list,tmpref);
        check_register_size(tosize,reg);
        sizes2load(fromsize,tosize,op,s);
 {$ifdef x86_64}
        { zero extensions to 64 bit on the x86_64 are simply done by writting to the lower 32 bit
          which clears the upper 64 bit too, so it could be that s is S_L while the reg is
          64 bit (FK) }
        if s in [S_BL,S_WL,S_L] then
          reg:=makeregsize(list,reg,OS_32);
{$endif x86_64}
        list.concat(taicpu.op_ref_reg(op,s,tmpref,reg));
      end;


    procedure tcgx86.a_load_reg_reg(list : TAsmList;fromsize,tosize : tcgsize;reg1,reg2 : tregister);
      var
        op: tasmop;
        s: topsize;
        instr:Taicpu;
      begin
        check_register_size(fromsize,reg1);
        check_register_size(tosize,reg2);
        if tcgsize2size[fromsize]>tcgsize2size[tosize] then
          begin
            reg1:=makeregsize(list,reg1,tosize);
            s:=tcgsize2opsize[tosize];
            op:=A_MOV;
          end
        else
          sizes2load(fromsize,tosize,op,s);
{$ifdef x86_64}
        { zero extensions to 64 bit on the x86_64 are simply done by writting to the lower 32 bit
          which clears the upper 64 bit too, so it could be that s is S_L while the reg is
          64 bit (FK)
        }
        if s in [S_BL,S_WL,S_L] then
          reg2:=makeregsize(list,reg2,OS_32);
{$endif x86_64}
        if (reg1<>reg2) then
          begin
            instr:=taicpu.op_reg_reg(op,s,reg1,reg2);
            { Notify the register allocator that we have written a move instruction so
              it can try to eliminate it. }
            if (reg1<>current_procinfo.framepointer) and (reg1<>NR_STACK_POINTER_REG) then
              add_move_instruction(instr);
            list.concat(instr);
          end;
{$ifdef x86_64}
        { avoid merging of registers and killing the zero extensions (FK) }
        if (tosize in [OS_64,OS_S64]) and (s=S_L) then
          list.concat(taicpu.op_const_reg(A_AND,S_L,$ffffffff,reg2));
{$endif x86_64}
      end;


    procedure tcgx86.a_loadaddr_ref_reg(list : TAsmList;const ref : treference;r : tregister);
      var
        tmpref  : treference;
      begin
        with ref do
          begin
            if (base=NR_NO) and (index=NR_NO) then
              begin
                if assigned(ref.symbol) then
                  begin
                    if (target_info.system in [system_i386_darwin,system_i386_iphonesim]) and
                       ((ref.symbol.bind in [AB_EXTERNAL,AB_WEAK_EXTERNAL]) or
                        (cs_create_pic in current_settings.moduleswitches)) then
                      begin
                        if (ref.symbol.bind in [AB_EXTERNAL,AB_WEAK_EXTERNAL]) or
                           ((cs_create_pic in current_settings.moduleswitches) and
                            (ref.symbol.bind in [AB_COMMON,AB_GLOBAL,AB_PRIVATE_EXTERN])) then
                          begin
                             reference_reset_base(tmpref,
                               g_indirect_sym_load(list,ref.symbol.name,asmsym2indsymflags(ref.symbol)),
                               offset,sizeof(pint));
                             a_loadaddr_ref_reg(list,tmpref,r);
                          end
                       else
                         begin
                           include(current_procinfo.flags,pi_needs_got);
                           reference_reset_base(tmpref,current_procinfo.got,offset,ref.alignment);
                           tmpref.symbol:=symbol;
                           tmpref.relsymbol:=current_procinfo.CurrGOTLabel;
                           list.concat(Taicpu.op_ref_reg(A_LEA,tcgsize2opsize[OS_ADDR],tmpref,r));
                         end;
                      end
                    else if (cs_create_pic in current_settings.moduleswitches)
{$ifdef x86_64}
                             and not(ref.symbol.bind=AB_LOCAL)
{$endif x86_64}
                            then
                      begin
{$ifdef x86_64}
                        reference_reset_symbol(tmpref,ref.symbol,0,ref.alignment);
                        tmpref.refaddr:=addr_pic;
                        tmpref.base:=NR_RIP;
                        list.concat(taicpu.op_ref_reg(A_MOV,S_Q,tmpref,r));
{$else x86_64}
                        reference_reset_symbol(tmpref,ref.symbol,0,ref.alignment);
                        tmpref.refaddr:=addr_pic;
                        tmpref.base:=current_procinfo.got;
                        include(current_procinfo.flags,pi_needs_got);
                        list.concat(taicpu.op_ref_reg(A_MOV,S_L,tmpref,r));
{$endif x86_64}
                        if offset<>0 then
                          a_op_const_reg(list,OP_ADD,OS_ADDR,offset,r);
                      end
{$ifdef x86_64}
                    else if (target_info.system in (systems_all_windows+[system_x86_64_darwin]))
			 or (cs_create_pic in current_settings.moduleswitches)
			 then
                      begin
                        { Win64 and Darwin/x86_64 always require RIP-relative addressing }
                        tmpref:=ref;
                        tmpref.base:=NR_RIP;
                        tmpref.refaddr:=addr_pic_no_got;
                        list.concat(Taicpu.op_ref_reg(A_LEA,S_Q,tmpref,r));
                      end
{$endif x86_64}
                    else
                      begin
                        tmpref:=ref;
                        tmpref.refaddr:=ADDR_FULL;
                        list.concat(Taicpu.op_ref_reg(A_MOV,tcgsize2opsize[OS_ADDR],tmpref,r));
                      end
                  end
                else
                  a_load_const_reg(list,OS_ADDR,offset,r)
              end
            else if (base=NR_NO) and (index<>NR_NO) and
                    (offset=0) and (scalefactor=0) and (symbol=nil) then
              a_load_reg_reg(list,OS_ADDR,OS_ADDR,index,r)
            else if (base<>NR_NO) and (index=NR_NO) and
                    (offset=0) and (symbol=nil) then
                a_load_reg_reg(list,OS_ADDR,OS_ADDR,base,r)
            else
              begin
                tmpref:=ref;
                make_simple_ref(list,tmpref);
                list.concat(Taicpu.op_ref_reg(A_LEA,tcgsize2opsize[OS_ADDR],tmpref,r));
              end;
            if segment<>NR_NO then
              begin
                if (tf_section_threadvars in target_info.flags) then
                  begin
                    { Convert thread local address to a process global addres
                      as we cannot handle far pointers.}
                    case target_info.system of
                      system_i386_linux:
                        if segment=NR_GS then
                          begin
                            reference_reset_symbol(tmpref,current_asmdata.RefAsmSymbol('___fpc_threadvar_offset'),0,ref.alignment);
                            tmpref.segment:=NR_GS;
                            list.concat(Taicpu.op_ref_reg(A_ADD,tcgsize2opsize[OS_ADDR],tmpref,r));
                          end
                        else
                          cgmessage(cg_e_cant_use_far_pointer_there);
                      system_i386_win32:
                        if segment=NR_FS then
                          begin
                            allocallcpuregisters(list);
                            a_call_name(list,'GetTls',false);
                            deallocallcpuregisters(list);
                            list.concat(Taicpu.op_reg_reg(A_ADD,tcgsize2opsize[OS_ADDR],NR_EAX,r));
                          end
                        else
                          cgmessage(cg_e_cant_use_far_pointer_there);

                      else
                        cgmessage(cg_e_cant_use_far_pointer_there);
                    end;
                  end
                else
                  cgmessage(cg_e_cant_use_far_pointer_there);
              end;
          end;
      end;


    { all fpu load routines expect that R_ST[0-7] means an fpu regvar and }
    { R_ST means "the current value at the top of the fpu stack" (JM)     }
    procedure tcgx86.a_loadfpu_reg_reg(list: TAsmList; fromsize, tosize: tcgsize; reg1, reg2: tregister);

       var
         href: treference;
         op: tasmop;
         s: topsize;
       begin
         if (reg1<>NR_ST) then
           begin
             floatloadops(tosize,op,s);
             list.concat(taicpu.op_reg(op,s,rgfpu.correct_fpuregister(reg1,rgfpu.fpuvaroffset)));
             inc_fpu_stack;
           end;
         if (reg2<>NR_ST) then
           begin
             floatstoreops(tosize,op,s);
             list.concat(taicpu.op_reg(op,s,rgfpu.correct_fpuregister(reg2,rgfpu.fpuvaroffset)));
             dec_fpu_stack;
           end;
         { OS_F80 < OS_C64, but OS_C64 fits perfectly in OS_F80 }
         if (reg1=NR_ST) and
            (reg2=NR_ST) and
            (tosize<>OS_F80) and
            (tosize<fromsize) then
           begin
             { can't round down to lower precision in x87 :/ }
             tg.gettemp(list,tcgsize2size[tosize],tcgsize2size[tosize],tt_normal,href);
             a_loadfpu_reg_ref(list,fromsize,tosize,NR_ST,href);
             a_loadfpu_ref_reg(list,tosize,tosize,href,NR_ST);
             tg.ungettemp(list,href);
           end;
       end;


    procedure tcgx86.a_loadfpu_ref_reg(list: TAsmList; fromsize, tosize: tcgsize; const ref: treference; reg: tregister);
       begin
         floatload(list,fromsize,ref);
         a_loadfpu_reg_reg(list,fromsize,tosize,NR_ST,reg);
       end;


    procedure tcgx86.a_loadfpu_reg_ref(list: TAsmList; fromsize,tosize: tcgsize; reg: tregister; const ref: treference);
       begin
         { in case a record returned in a floating point register
           (LOC_FPUREGISTER with OS_F32/OS_F64) is stored in memory
           (LOC_REFERENCE with OS_32/OS_64), we have to adjust the
           tosize }
        if (fromsize in [OS_F32,OS_F64]) and
           (tcgsize2size[fromsize]=tcgsize2size[tosize]) then
          case tosize of
            OS_32:
              tosize:=OS_F32;
            OS_64:
              tosize:=OS_F64;
          end;
         if reg<>NR_ST then
           a_loadfpu_reg_reg(list,fromsize,tosize,reg,NR_ST);
         floatstore(list,tosize,ref);
       end;


    function get_scalar_mm_op(fromsize,tosize : tcgsize) : tasmop;
      const
        convertop : array[OS_F32..OS_F128,OS_F32..OS_F128] of tasmop = (
          (A_MOVSS,A_CVTSS2SD,A_NONE,A_NONE,A_NONE),
          (A_CVTSD2SS,A_MOVSD,A_NONE,A_NONE,A_NONE),
          (A_NONE,A_NONE,A_NONE,A_NONE,A_NONE),
          (A_NONE,A_NONE,A_NONE,A_MOVQ,A_NONE),
          (A_NONE,A_NONE,A_NONE,A_NONE,A_NONE));
      begin
        { we can have OS_F32/OS_F64 (record in function result/LOC_MMREGISTER) to
          OS_32/OS_64 (record in memory/LOC_REFERENCE) }
        if (fromsize in [OS_F32,OS_F64]) and
           (tcgsize2size[fromsize]=tcgsize2size[tosize]) then
          case tosize of
            OS_32:
              tosize:=OS_F32;
            OS_64:
              tosize:=OS_F64;
          end;
        if (fromsize in [low(convertop)..high(convertop)]) and
           (tosize in [low(convertop)..high(convertop)]) then
          result:=convertop[fromsize,tosize]
        { we can have OS_M64 (record in function result/LOC_MMREGISTER) to
          OS_64 (record in memory/LOC_REFERENCE) }
        else if (tcgsize2size[fromsize]=tcgsize2size[tosize]) and
                (fromsize=OS_M64) then
          result:=A_MOVQ
        else
          internalerror(2010060104);
        if result=A_NONE then
          internalerror(200312205);
      end;


    procedure tcgx86.a_loadmm_reg_reg(list: TAsmList; fromsize, tosize : tcgsize;reg1, reg2: tregister;shuffle : pmmshuffle);
      var
        instr : taicpu;
      begin
        if shuffle=nil then
          begin
            if fromsize=tosize then
              { needs correct size in case of spilling }
              case fromsize of
                OS_F32:
                  instr:=taicpu.op_reg_reg(A_MOVAPS,S_NO,reg1,reg2);
                OS_F64:
                  instr:=taicpu.op_reg_reg(A_MOVAPD,S_NO,reg1,reg2);
                OS_M64:
                  instr:=taicpu.op_reg_reg(A_MOVQ,S_NO,reg1,reg2);
                else
                  internalerror(2006091201);
              end
            else
              internalerror(200312202);
            add_move_instruction(instr);
          end
        else if shufflescalar(shuffle) then
          begin
            instr:=taicpu.op_reg_reg(get_scalar_mm_op(fromsize,tosize),S_NO,reg1,reg2);
            case get_scalar_mm_op(fromsize,tosize) of
              A_MOVSS,
              A_MOVSD,
              A_MOVQ:
                add_move_instruction(instr);
            end;
          end
        else
          internalerror(200312201);
        list.concat(instr);
      end;


    procedure tcgx86.a_loadmm_ref_reg(list: TAsmList; fromsize, tosize : tcgsize;const ref: treference; reg: tregister;shuffle : pmmshuffle);
       var
         tmpref  : treference;
       begin
         tmpref:=ref;
         make_simple_ref(list,tmpref);
         if shuffle=nil then
           begin
             if fromsize=OS_M64 then
               list.concat(taicpu.op_ref_reg(A_MOVQ,S_NO,tmpref,reg))
             else
{$ifdef x86_64}
               { x86-64 has always properly aligned data }
               list.concat(taicpu.op_ref_reg(A_MOVDQA,S_NO,tmpref,reg));
{$else x86_64}
               list.concat(taicpu.op_ref_reg(A_MOVDQU,S_NO,tmpref,reg));
{$endif x86_64}
           end
         else if shufflescalar(shuffle) then
           list.concat(taicpu.op_ref_reg(get_scalar_mm_op(fromsize,tosize),S_NO,tmpref,reg))
         else
           internalerror(200312252);
       end;


    procedure tcgx86.a_loadmm_reg_ref(list: TAsmList; fromsize, tosize : tcgsize;reg: tregister; const ref: treference;shuffle : pmmshuffle);
       var
         hreg : tregister;
         tmpref  : treference;
       begin
         tmpref:=ref;
         make_simple_ref(list,tmpref);
         if shuffle=nil then
           begin
             if fromsize=OS_M64 then
               list.concat(taicpu.op_reg_ref(A_MOVQ,S_NO,reg,tmpref))
             else
{$ifdef x86_64}
               { x86-64 has always properly aligned data }
               list.concat(taicpu.op_reg_ref(A_MOVDQA,S_NO,reg,tmpref))
{$else x86_64}
               list.concat(taicpu.op_reg_ref(A_MOVDQU,S_NO,reg,tmpref))
{$endif x86_64}
           end
         else if shufflescalar(shuffle) then
           begin
             if tcgsize2size[tosize]<>tcgsize2size[fromsize] then
               begin
                 hreg:=getmmregister(list,tosize);
                 list.concat(taicpu.op_reg_reg(get_scalar_mm_op(fromsize,tosize),S_NO,reg,hreg));
                 list.concat(taicpu.op_reg_ref(get_scalar_mm_op(tosize,tosize),S_NO,hreg,tmpref));
               end
             else
               list.concat(taicpu.op_reg_ref(get_scalar_mm_op(fromsize,tosize),S_NO,reg,tmpref));
           end
         else
           internalerror(200312252);
       end;


    procedure tcgx86.a_opmm_ref_reg(list: TAsmList; Op: TOpCG; size : tcgsize;const ref: treference; reg: tregister;shuffle : pmmshuffle);
      var
        l : tlocation;
      begin
        l.loc:=LOC_REFERENCE;
        l.reference:=ref;
        l.size:=size;
        opmm_loc_reg(list,op,size,l,reg,shuffle);
      end;


    procedure tcgx86.a_opmm_reg_reg(list: TAsmList; Op: TOpCG; size : tcgsize;src,dst: tregister;shuffle : pmmshuffle);
     var
       l : tlocation;
     begin
       l.loc:=LOC_MMREGISTER;
       l.register:=src;
       l.size:=size;
       opmm_loc_reg(list,op,size,l,dst,shuffle);
     end;


    procedure tcgx86.opmm_loc_reg(list: TAsmList; Op: TOpCG; size : tcgsize;loc : tlocation;dst: tregister; shuffle : pmmshuffle);
      const
        opmm2asmop : array[0..1,OS_F32..OS_F64,topcg] of tasmop = (
          ( { scalar }
            ( { OS_F32 }
              A_NOP,A_NOP,A_ADDSS,A_NOP,A_DIVSS,A_NOP,A_NOP,A_MULSS,A_NOP,A_NOP,A_NOP,A_NOP,A_NOP,A_NOP,A_SUBSS,A_NOP,A_NOP,A_NOP
            ),
            ( { OS_F64 }
              A_NOP,A_NOP,A_ADDSD,A_NOP,A_DIVSD,A_NOP,A_NOP,A_MULSD,A_NOP,A_NOP,A_NOP,A_NOP,A_NOP,A_NOP,A_SUBSD,A_NOP,A_NOP,A_NOP
            )
          ),
          ( { vectorized/packed }
            { because the logical packed single instructions have shorter op codes, we use always
              these
            }
            ( { OS_F32 }
              A_NOP,A_NOP,A_ADDPS,A_NOP,A_DIVPS,A_NOP,A_NOP,A_MULPS,A_NOP,A_NOP,A_NOP,A_NOP,A_NOP,A_NOP,A_SUBPS,A_XORPS,A_NOP,A_NOP
            ),
            ( { OS_F64 }
              A_NOP,A_NOP,A_ADDPD,A_NOP,A_DIVPD,A_NOP,A_NOP,A_MULPD,A_NOP,A_NOP,A_NOP,A_NOP,A_NOP,A_NOP,A_SUBPD,A_XORPD,A_NOP,A_NOP
            )
          )
        );

      var
        resultreg : tregister;
        asmop : tasmop;
      begin
        { this is an internally used procedure so the parameters have
          some constrains
        }
        if loc.size<>size then
          internalerror(200312213);
        resultreg:=dst;
        { deshuffle }
        //!!!
        if (shuffle<>nil) and not(shufflescalar(shuffle)) then
          begin
            internalerror(2010060101);
          end
        else if (shuffle=nil) then
          asmop:=opmm2asmop[1,size,op]
        else if shufflescalar(shuffle) then
          begin
            asmop:=opmm2asmop[0,size,op];
            { no scalar operation available? }
            if asmop=A_NOP then
              begin
                { do vectorized and shuffle finally }
                internalerror(2010060102);
              end;
          end
        else
          internalerror(200312211);
        if asmop=A_NOP then
          internalerror(200312216);
        case loc.loc of
          LOC_CREFERENCE,LOC_REFERENCE:
            begin
              make_simple_ref(current_asmdata.CurrAsmList,loc.reference);
              list.concat(taicpu.op_ref_reg(asmop,S_NO,loc.reference,resultreg));
            end;
          LOC_CMMREGISTER,LOC_MMREGISTER:
            list.concat(taicpu.op_reg_reg(asmop,S_NO,loc.register,resultreg));
          else
            internalerror(200312214);
        end;
        { shuffle }
        if resultreg<>dst then
          begin
            internalerror(200312212);
          end;
      end;


    procedure tcgx86.a_op_const_reg(list : TAsmList; Op: TOpCG; size: TCGSize; a: tcgint; reg: TRegister);

      var
        opcode : tasmop;
        power  : longint;
{$ifdef x86_64}
        tmpreg : tregister;
{$endif x86_64}
      begin
        optimize_op_const(op, a);
{$ifdef x86_64}
        { x86_64 only supports signed 32 bits constants directly }
        if not(op in [OP_NONE,OP_MOVE]) and
           (size in [OS_S64,OS_64]) and
            ((a<low(longint)) or (a>high(longint))) then
          begin
            tmpreg:=getintregister(list,size);
            a_load_const_reg(list,size,a,tmpreg);
            a_op_reg_reg(list,op,size,tmpreg,reg);
            exit;
          end;
{$endif x86_64}
        check_register_size(size,reg);
        case op of
          OP_NONE :
            begin
              { Opcode is optimized away }
            end;
          OP_MOVE :
            begin
              { Optimized, replaced with a simple load }
              a_load_const_reg(list,size,a,reg);
            end;
          OP_DIV, OP_IDIV:
            begin
              if ispowerof2(int64(a),power) then
                begin
                  case op of
                    OP_DIV:
                      opcode := A_SHR;
                    OP_IDIV:
                      opcode := A_SAR;
                  end;
                  list.concat(taicpu.op_const_reg(opcode,TCgSize2OpSize[size],power,reg));
                  exit;
                end;
              { the rest should be handled specifically in the code      }
              { generator because of the silly register usage restraints }
              internalerror(200109224);
            end;
          OP_MUL,OP_IMUL:
            begin
              if not(cs_check_overflow in current_settings.localswitches) and
                 ispowerof2(int64(a),power) then
                begin
                  list.concat(taicpu.op_const_reg(A_SHL,TCgSize2OpSize[size],power,reg));
                  exit;
                end;
              if op = OP_IMUL then
                list.concat(taicpu.op_const_reg(A_IMUL,TCgSize2OpSize[size],a,reg))
              else
                { OP_MUL should be handled specifically in the code        }
                { generator because of the silly register usage restraints }
                internalerror(200109225);
            end;
          OP_ADD, OP_AND, OP_OR, OP_SUB, OP_XOR:
            if not(cs_check_overflow in current_settings.localswitches) and
               (a = 1) and
               (op in [OP_ADD,OP_SUB]) then
              if op = OP_ADD then
                list.concat(taicpu.op_reg(A_INC,TCgSize2OpSize[size],reg))
              else
                list.concat(taicpu.op_reg(A_DEC,TCgSize2OpSize[size],reg))
            else if (a = 0) then
              if (op <> OP_AND) then
                exit
              else
                list.concat(taicpu.op_const_reg(A_MOV,TCgSize2OpSize[size],0,reg))
            else if (aword(a) = high(aword)) and
                    (op in [OP_AND,OP_OR,OP_XOR]) then
                   begin
                     case op of
                       OP_AND:
                         exit;
                       OP_OR:
                         list.concat(taicpu.op_const_reg(A_MOV,TCgSize2OpSize[size],aint(high(aword)),reg));
                       OP_XOR:
                         list.concat(taicpu.op_reg(A_NOT,TCgSize2OpSize[size],reg));
                     end
                   end
            else
              list.concat(taicpu.op_const_reg(TOpCG2AsmOp[op],TCgSize2OpSize[size],aint(a),reg));
          OP_SHL,OP_SHR,OP_SAR,OP_ROL,OP_ROR:
            begin
{$ifdef x86_64}
              if (a and 63) <> 0 Then
                list.concat(taicpu.op_const_reg(TOpCG2AsmOp[op],TCgSize2OpSize[size],a and 63,reg));
              if (a shr 6) <> 0 Then
                internalerror(200609073);
{$else x86_64}
              if (a and 31) <> 0 Then
                list.concat(taicpu.op_const_reg(TOpCG2AsmOp[op],TCgSize2OpSize[size],a and 31,reg));
              if (a shr 5) <> 0 Then
                internalerror(200609071);
{$endif x86_64}
            end
          else internalerror(200609072);
        end;
      end;


    procedure tcgx86.a_op_const_ref(list : TAsmList; Op: TOpCG; size: TCGSize; a: tcgint; const ref: TReference);
      var
        opcode: tasmop;
        power: longint;
{$ifdef x86_64}
        tmpreg : tregister;
{$endif x86_64}
        tmpref  : treference;
      begin
        optimize_op_const(op, a);
        tmpref:=ref;
        make_simple_ref(list,tmpref);
{$ifdef x86_64}
        { x86_64 only supports signed 32 bits constants directly }
        if not(op in [OP_NONE,OP_MOVE]) and
           (size in [OS_S64,OS_64]) and
            ((a<low(longint)) or (a>high(longint))) then
          begin
            tmpreg:=getintregister(list,size);
            a_load_const_reg(list,size,a,tmpreg);
            a_op_reg_ref(list,op,size,tmpreg,tmpref);
            exit;
          end;
{$endif x86_64}
        Case Op of
          OP_NONE :
            begin
              { Opcode is optimized away }
            end;
          OP_MOVE :
            begin
              { Optimized, replaced with a simple load }
              a_load_const_ref(list,size,a,ref);
            end;
          OP_DIV, OP_IDIV:
            Begin
              if ispowerof2(int64(a),power) then
                begin
                  case op of
                    OP_DIV:
                      opcode := A_SHR;
                    OP_IDIV:
                      opcode := A_SAR;
                  end;
                  list.concat(taicpu.op_const_ref(opcode,
                    TCgSize2OpSize[size],power,tmpref));
                  exit;
                end;
              { the rest should be handled specifically in the code      }
              { generator because of the silly register usage restraints }
              internalerror(200109231);
            End;
          OP_MUL,OP_IMUL:
            begin
              if not(cs_check_overflow in current_settings.localswitches) and
                 ispowerof2(int64(a),power) then
                begin
                  list.concat(taicpu.op_const_ref(A_SHL,TCgSize2OpSize[size],
                    power,tmpref));
                  exit;
                end;
              { can't multiply a memory location directly with a constant }
              if op = OP_IMUL then
                inherited a_op_const_ref(list,op,size,a,tmpref)
              else
                { OP_MUL should be handled specifically in the code        }
                { generator because of the silly register usage restraints }
                internalerror(200109232);
            end;
          OP_ADD, OP_AND, OP_OR, OP_SUB, OP_XOR:
            if not(cs_check_overflow in current_settings.localswitches) and
               (a = 1) and
               (op in [OP_ADD,OP_SUB]) then
              if op = OP_ADD then
                list.concat(taicpu.op_ref(A_INC,TCgSize2OpSize[size],tmpref))
              else
                list.concat(taicpu.op_ref(A_DEC,TCgSize2OpSize[size],tmpref))
            else if (a = 0) then
              if (op <> OP_AND) then
                exit
              else
                a_load_const_ref(list,size,0,tmpref)
            else if (aword(a) = high(aword)) and
                    (op in [OP_AND,OP_OR,OP_XOR]) then
                   begin
                     case op of
                       OP_AND:
                         exit;
                       OP_OR:
                         list.concat(taicpu.op_const_ref(A_MOV,TCgSize2OpSize[size],aint(high(aword)),tmpref));
                       OP_XOR:
                         list.concat(taicpu.op_ref(A_NOT,TCgSize2OpSize[size],tmpref));
                     end
                   end
            else
              list.concat(taicpu.op_const_ref(TOpCG2AsmOp[op],
                TCgSize2OpSize[size],a,tmpref));
          OP_SHL,OP_SHR,OP_SAR,OP_ROL,OP_ROR:
            begin
              if (a and 31) <> 0 then
                list.concat(taicpu.op_const_ref(
                  TOpCG2AsmOp[op],TCgSize2OpSize[size],a and 31,tmpref));
              if (a shr 5) <> 0 Then
                internalerror(68991);
            end
          else internalerror(68992);
        end;
      end;


    procedure tcgx86.a_op_reg_reg(list : TAsmList; Op: TOpCG; size: TCGSize; src, dst: TRegister);
      var
        dstsize: topsize;
        instr:Taicpu;
      begin
        check_register_size(size,src);
        check_register_size(size,dst);
        dstsize := tcgsize2opsize[size];
        case op of
          OP_NEG,OP_NOT:
            begin
              if src<>dst then
                a_load_reg_reg(list,size,size,src,dst);
              list.concat(taicpu.op_reg(TOpCG2AsmOp[op],dstsize,dst));
            end;
          OP_MUL,OP_DIV,OP_IDIV:
            { special stuff, needs separate handling inside code }
            { generator                                          }
            internalerror(200109233);
          OP_SHR,OP_SHL,OP_SAR,OP_ROL,OP_ROR:
            begin
              { Use ecx to load the value, that allows better coalescing }
              getcpuregister(list,NR_ECX);
              a_load_reg_reg(list,size,OS_32,src,NR_ECX);
              list.concat(taicpu.op_reg_reg(Topcg2asmop[op],tcgsize2opsize[size],NR_CL,dst));
              ungetcpuregister(list,NR_ECX);
            end;
          else
            begin
              if reg2opsize(src) <> dstsize then
                internalerror(200109226);
              instr:=taicpu.op_reg_reg(TOpCG2AsmOp[op],dstsize,src,dst);
              list.concat(instr);
            end;
        end;
      end;


    procedure tcgx86.a_op_ref_reg(list : TAsmList; Op: TOpCG; size: TCGSize; const ref: TReference; reg: TRegister);
      var
        tmpref  : treference;
      begin
        tmpref:=ref;
        make_simple_ref(list,tmpref);
        check_register_size(size,reg);
        case op of
          OP_NEG,OP_NOT,OP_IMUL:
            begin
              inherited a_op_ref_reg(list,op,size,tmpref,reg);
            end;
          OP_MUL,OP_DIV,OP_IDIV:
            { special stuff, needs separate handling inside code }
            { generator                                          }
            internalerror(200109239);
          else
            begin
              reg := makeregsize(list,reg,size);
              list.concat(taicpu.op_ref_reg(TOpCG2AsmOp[op],tcgsize2opsize[size],tmpref,reg));
            end;
        end;
      end;


    procedure tcgx86.a_op_reg_ref(list : TAsmList; Op: TOpCG; size: TCGSize;reg: TRegister; const ref: TReference);
      var
        tmpref  : treference;
      begin
        tmpref:=ref;
        make_simple_ref(list,tmpref);
        check_register_size(size,reg);
        case op of
          OP_NEG,OP_NOT:
            begin
              if reg<>NR_NO then
                internalerror(200109237);
              list.concat(taicpu.op_ref(TOpCG2AsmOp[op],tcgsize2opsize[size],tmpref));
            end;
          OP_IMUL:
            begin
              { this one needs a load/imul/store, which is the default }
              inherited a_op_ref_reg(list,op,size,tmpref,reg);
            end;
          OP_MUL,OP_DIV,OP_IDIV:
            { special stuff, needs separate handling inside code }
            { generator                                          }
            internalerror(200109238);
          else
            begin
              list.concat(taicpu.op_reg_ref(TOpCG2AsmOp[op],tcgsize2opsize[size],reg,tmpref));
            end;
        end;
      end;

     procedure tcgx86.a_bit_scan_reg_reg(list: TAsmList; reverse: boolean; size: TCGSize; src, dst: TRegister);
     var
       opsize: topsize;
     begin
       opsize:=tcgsize2opsize[size];
       if not reverse then
         list.concat(taicpu.op_reg_reg(A_BSF,opsize,src,dst))
       else
         list.concat(taicpu.op_reg_reg(A_BSR,opsize,src,dst));
     end;

{*************** compare instructructions ****************}

    procedure tcgx86.a_cmp_const_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;a : tcgint;reg : tregister;
      l : tasmlabel);

{$ifdef x86_64}
      var
        tmpreg : tregister;
{$endif x86_64}
      begin
{$ifdef x86_64}
        { x86_64 only supports signed 32 bits constants directly }
        if (size in [OS_S64,OS_64]) and
            ((a<low(longint)) or (a>high(longint))) then
          begin
            tmpreg:=getintregister(list,size);
            a_load_const_reg(list,size,a,tmpreg);
            a_cmp_reg_reg_label(list,size,cmp_op,tmpreg,reg,l);
            exit;
          end;
{$endif x86_64}
        if (a = 0) then
          list.concat(taicpu.op_reg_reg(A_TEST,tcgsize2opsize[size],reg,reg))
        else
          list.concat(taicpu.op_const_reg(A_CMP,tcgsize2opsize[size],a,reg));
        a_jmp_cond(list,cmp_op,l);
      end;


    procedure tcgx86.a_cmp_const_ref_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;a : tcgint;const ref : treference;
      l : tasmlabel);

      var
{$ifdef x86_64}
        tmpreg : tregister;
{$endif x86_64}
        tmpref  : treference;
      begin
        tmpref:=ref;
        make_simple_ref(list,tmpref);
{$ifdef x86_64}
        { x86_64 only supports signed 32 bits constants directly }
        if (size in [OS_S64,OS_64]) and
           ((a<low(longint)) or (a>high(longint))) then
          begin
            tmpreg:=getintregister(list,size);
            a_load_const_reg(list,size,a,tmpreg);
            a_cmp_reg_ref_label(list,size,cmp_op,tmpreg,tmpref,l);
            exit;
          end;
{$endif x86_64}
        list.concat(taicpu.op_const_ref(A_CMP,TCgSize2OpSize[size],a,tmpref));
        a_jmp_cond(list,cmp_op,l);
      end;


    procedure tcgx86.a_cmp_reg_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;
      reg1,reg2 : tregister;l : tasmlabel);

      begin
        check_register_size(size,reg1);
        check_register_size(size,reg2);
        list.concat(taicpu.op_reg_reg(A_CMP,TCgSize2OpSize[size],reg1,reg2));
        a_jmp_cond(list,cmp_op,l);
      end;


    procedure tcgx86.a_cmp_ref_reg_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;const ref: treference; reg : tregister;l : tasmlabel);
      var
        tmpref  : treference;
      begin
        tmpref:=ref;
        make_simple_ref(list,tmpref);
        check_register_size(size,reg);
        list.concat(taicpu.op_ref_reg(A_CMP,TCgSize2OpSize[size],tmpref,reg));
        a_jmp_cond(list,cmp_op,l);
      end;


    procedure tcgx86.a_cmp_reg_ref_label(list : TAsmList;size : tcgsize;cmp_op : topcmp;reg : tregister;const ref: treference; l : tasmlabel);
      var
        tmpref  : treference;
      begin
        tmpref:=ref;
        make_simple_ref(list,tmpref);
        check_register_size(size,reg);
        list.concat(taicpu.op_reg_ref(A_CMP,TCgSize2OpSize[size],reg,tmpref));
        a_jmp_cond(list,cmp_op,l);
      end;


    procedure tcgx86.a_jmp_cond(list : TAsmList;cond : TOpCmp;l: tasmlabel);
      var
        ai : taicpu;
      begin
        if cond=OC_None then
          ai := Taicpu.Op_sym(A_JMP,S_NO,l)
        else
          begin
            ai:=Taicpu.Op_sym(A_Jcc,S_NO,l);
            ai.SetCondition(TOpCmp2AsmCond[cond]);
          end;
        ai.is_jmp:=true;
        list.concat(ai);
      end;


     procedure tcgx86.a_jmp_flags(list : TAsmList;const f : TResFlags;l: tasmlabel);
       var
         ai : taicpu;
       begin
         ai := Taicpu.op_sym(A_Jcc,S_NO,l);
         ai.SetCondition(flags_to_cond(f));
         ai.is_jmp := true;
         list.concat(ai);
       end;


    procedure tcgx86.g_flags2reg(list: TAsmList; size: TCgSize; const f: tresflags; reg: TRegister);
      var
        ai : taicpu;
        hreg : tregister;
      begin
        hreg:=makeregsize(list,reg,OS_8);
        ai:=Taicpu.op_reg(A_SETcc,S_B,hreg);
        ai.setcondition(flags_to_cond(f));
        list.concat(ai);
        if reg<>hreg then
          a_load_reg_reg(list,OS_8,size,hreg,reg);
      end;


    procedure tcgx86.g_flags2ref(list: TAsmList; size: TCgSize; const f: tresflags; const ref: TReference);
      var
        ai : taicpu;
        tmpref  : treference;
      begin
         tmpref:=ref;
         make_simple_ref(list,tmpref);
         if not(size in [OS_8,OS_S8]) then
           a_load_const_ref(list,size,0,tmpref);
         ai:=Taicpu.op_ref(A_SETcc,S_B,tmpref);
         ai.setcondition(flags_to_cond(f));
         list.concat(ai);
{$ifndef cpu64bitalu}
         if size in [OS_S64,OS_64] then
           begin
             inc(tmpref.offset,4);
             a_load_const_ref(list,OS_32,0,tmpref);
           end;
{$endif cpu64bitalu}
      end;


{ ************* concatcopy ************ }

    procedure Tcgx86.g_concatcopy(list:TAsmList;const source,dest:Treference;len:tcgint);

    const
{$ifdef cpu64bitalu}
        REGCX=NR_RCX;
        REGSI=NR_RSI;
        REGDI=NR_RDI;
{$else cpu64bitalu}
        REGCX=NR_ECX;
        REGSI=NR_ESI;
        REGDI=NR_EDI;
{$endif cpu64bitalu}

    type  copymode=(copy_move,copy_mmx,copy_string);

    var srcref,dstref:Treference;
        r,r0,r1,r2,r3:Tregister;
        helpsize:tcgint;
        copysize:byte;
        cgsize:Tcgsize;
        cm:copymode;

    begin
      cm:=copy_move;
      helpsize:=3*sizeof(aword);
      if cs_opt_size in current_settings.optimizerswitches then
        helpsize:=2*sizeof(aword);
      if (cs_mmx in current_settings.localswitches) and
         not(pi_uses_fpu in current_procinfo.flags) and
         ((len=8) or (len=16) or (len=24) or (len=32)) then
        cm:=copy_mmx;
      if (len>helpsize) then
        cm:=copy_string;
      if (cs_opt_size in current_settings.optimizerswitches) and
         not((len<=16) and (cm=copy_mmx)) and
         not(len in [1,2,4{$ifdef x86_64},8{$endif x86_64}]) then
        cm:=copy_string;
      if (source.segment<>NR_NO) or
         (dest.segment<>NR_NO) then
        cm:=copy_string;
      case cm of
        copy_move:
          begin
            dstref:=dest;
            srcref:=source;
            copysize:=sizeof(aint);
            cgsize:=int_cgsize(copysize);
            while len<>0 do
              begin
                if len<2 then
                  begin
                    copysize:=1;
                    cgsize:=OS_8;
                  end
                else if len<4 then
                  begin
                    copysize:=2;
                    cgsize:=OS_16;
                  end
                else if len<8 then
                  begin
                    copysize:=4;
                    cgsize:=OS_32;
                  end
{$ifdef cpu64bitalu}
                else if len<16 then
                  begin
                    copysize:=8;
                    cgsize:=OS_64;
                  end
{$endif}
                ;
                dec(len,copysize);
                r:=getintregister(list,cgsize);
                a_load_ref_reg(list,cgsize,cgsize,srcref,r);
                a_load_reg_ref(list,cgsize,cgsize,r,dstref);
                inc(srcref.offset,copysize);
                inc(dstref.offset,copysize);
              end;
          end;
        copy_mmx:
          begin
            dstref:=dest;
            srcref:=source;
            r0:=getmmxregister(list);
            a_loadmm_ref_reg(list,OS_M64,OS_M64,srcref,r0,nil);
            if len>=16 then
              begin
                inc(srcref.offset,8);
                r1:=getmmxregister(list);
                a_loadmm_ref_reg(list,OS_M64,OS_M64,srcref,r1,nil);
              end;
            if len>=24 then
              begin
                inc(srcref.offset,8);
                r2:=getmmxregister(list);
                a_loadmm_ref_reg(list,OS_M64,OS_M64,srcref,r2,nil);
              end;
            if len>=32 then
              begin
                inc(srcref.offset,8);
                r3:=getmmxregister(list);
                a_loadmm_ref_reg(list,OS_M64,OS_M64,srcref,r3,nil);
              end;
            a_loadmm_reg_ref(list,OS_M64,OS_M64,r0,dstref,nil);
            if len>=16 then
              begin
                inc(dstref.offset,8);
                a_loadmm_reg_ref(list,OS_M64,OS_M64,r1,dstref,nil);
              end;
            if len>=24 then
              begin
                inc(dstref.offset,8);
                a_loadmm_reg_ref(list,OS_M64,OS_M64,r2,dstref,nil);
              end;
            if len>=32 then
              begin
                inc(dstref.offset,8);
                a_loadmm_reg_ref(list,OS_M64,OS_M64,r3,dstref,nil);
              end;
          end
        else {copy_string, should be a good fallback in case of unhandled}
          begin
            getcpuregister(list,REGDI);
            if (dest.segment=NR_NO) then
              a_loadaddr_ref_reg(list,dest,REGDI)
            else
              begin
                dstref:=dest;
                dstref.segment:=NR_NO;
                a_loadaddr_ref_reg(list,dstref,REGDI);
                list.concat(taicpu.op_reg(A_PUSH,S_L,NR_ES));
                list.concat(taicpu.op_reg(A_PUSH,S_L,dest.segment));
                list.concat(taicpu.op_reg(A_POP,S_L,NR_ES));
              end;
            getcpuregister(list,REGSI);
            if (source.segment=NR_NO) then
              a_loadaddr_ref_reg(list,source,REGSI)
            else
              begin
                srcref:=source;
                srcref.segment:=NR_NO;
                a_loadaddr_ref_reg(list,srcref,REGSI);
                list.concat(taicpu.op_reg(A_PUSH,S_L,NR_DS));
                list.concat(taicpu.op_reg(A_PUSH,S_L,source.segment));
                list.concat(taicpu.op_reg(A_POP,S_L,NR_DS));
              end;

            getcpuregister(list,REGCX);
{$ifdef i386}
           list.concat(Taicpu.op_none(A_CLD,S_NO));
{$endif i386}
            if (cs_opt_size in current_settings.optimizerswitches) and
               (len>sizeof(aint)+(sizeof(aint) div 2)) then
              begin
                a_load_const_reg(list,OS_INT,len,REGCX);
                list.concat(Taicpu.op_none(A_REP,S_NO));
                list.concat(Taicpu.op_none(A_MOVSB,S_NO));
              end
            else
              begin
                helpsize:=len div sizeof(aint);
                len:=len mod sizeof(aint);
                if helpsize>1 then
                  begin
                    a_load_const_reg(list,OS_INT,helpsize,REGCX);
                    list.concat(Taicpu.op_none(A_REP,S_NO));
                  end;
                if helpsize>0 then
                  begin
{$ifdef cpu64bitalu}
                    list.concat(Taicpu.op_none(A_MOVSQ,S_NO))
{$else}
                    list.concat(Taicpu.op_none(A_MOVSD,S_NO));
{$endif cpu64bitalu}
                  end;
                if len>=4 then
                  begin
                    dec(len,4);
                    list.concat(Taicpu.op_none(A_MOVSD,S_NO));
                  end;
                if len>=2 then
                  begin
                    dec(len,2);
                    list.concat(Taicpu.op_none(A_MOVSW,S_NO));
                  end;
                if len=1 then
                  list.concat(Taicpu.op_none(A_MOVSB,S_NO));
              end;
            ungetcpuregister(list,REGCX);
            ungetcpuregister(list,REGSI);
            ungetcpuregister(list,REGDI);
            if (source.segment<>NR_NO) then
              list.concat(taicpu.op_reg(A_POP,S_L,NR_DS));
            if (dest.segment<>NR_NO) then
              list.concat(taicpu.op_reg(A_POP,S_L,NR_ES));
          end;
        end;
    end;


{****************************************************************************
                              Entry/Exit Code Helpers
****************************************************************************}

    procedure tcgx86.g_profilecode(list : TAsmList);

      var
        pl           : tasmlabel;
        mcountprefix : String[4];

      begin
        case target_info.system of
        {$ifndef NOTARGETWIN}
           system_i386_win32,
        {$endif}
           system_i386_freebsd,
           system_i386_netbsd,
//         system_i386_openbsd,
           system_i386_wdosx :
             begin
                Case target_info.system Of
                 system_i386_freebsd : mcountprefix:='.';
                 system_i386_netbsd : mcountprefix:='__';
//               system_i386_openbsd : mcountprefix:='.';
                else
                 mcountPrefix:='';
                end;
                current_asmdata.getaddrlabel(pl);
                new_section(list,sec_data,lower(current_procinfo.procdef.mangledname),sizeof(pint));
                list.concat(Tai_label.Create(pl));
                list.concat(Tai_const.Create_32bit(0));
                new_section(list,sec_code,lower(current_procinfo.procdef.mangledname),0);
                list.concat(Taicpu.Op_reg(A_PUSH,S_L,NR_EDX));
                list.concat(Taicpu.Op_sym_ofs_reg(A_MOV,S_L,pl,0,NR_EDX));
                a_call_name(list,target_info.Cprefix+mcountprefix+'mcount',false);
                list.concat(Taicpu.Op_reg(A_POP,S_L,NR_EDX));
             end;

           system_i386_linux:
             a_call_name(list,target_info.Cprefix+'mcount',false);

           system_i386_go32v2,system_i386_watcom:
             begin
               a_call_name(list,'MCOUNT',false);
             end;
           system_x86_64_linux,
           system_x86_64_darwin:
             begin
               a_call_name(list,'mcount',false);
             end;
        end;
      end;


    procedure tcgx86.g_stackpointer_alloc(list : TAsmList;localsize : longint);
{$ifdef x86}
{$ifndef NOTARGETWIN}
      var
        href : treference;
        i : integer;
        again : tasmlabel;
{$endif NOTARGETWIN}
{$endif x86}
      begin
        if localsize>0 then
         begin
{$ifdef i386}
{$ifndef NOTARGETWIN}
           { windows guards only a few pages for stack growing,
             so we have to access every page first              }
           if (target_info.system in [system_i386_win32,system_i386_wince]) and
              (localsize>=winstackpagesize) then
             begin
               if localsize div winstackpagesize<=5 then
                 begin
                    list.concat(Taicpu.Op_const_reg(A_SUB,S_L,localsize-4,NR_ESP));
                    for i:=1 to localsize div winstackpagesize do
                      begin
                         reference_reset_base(href,NR_ESP,localsize-i*winstackpagesize,4);
                         list.concat(Taicpu.op_reg_ref(A_MOV,S_L,NR_EAX,href));
                      end;
                    list.concat(Taicpu.op_reg(A_PUSH,S_L,NR_EAX));
                 end
               else
                 begin
                    current_asmdata.getjumplabel(again);
                    getcpuregister(list,NR_EDI);
                    list.concat(Taicpu.op_reg(A_PUSH,S_L,NR_EDI));
                    list.concat(Taicpu.op_const_reg(A_MOV,S_L,localsize div winstackpagesize,NR_EDI));
                    a_label(list,again);
                    list.concat(Taicpu.op_const_reg(A_SUB,S_L,winstackpagesize-4,NR_ESP));
                    list.concat(Taicpu.op_reg(A_PUSH,S_L,NR_EAX));
                    list.concat(Taicpu.op_reg(A_DEC,S_L,NR_EDI));
                    a_jmp_cond(list,OC_NE,again);
                    list.concat(Taicpu.op_const_reg(A_SUB,S_L,localsize mod winstackpagesize - 4,NR_ESP));
                    reference_reset_base(href,NR_ESP,localsize-4,4);
                    list.concat(Taicpu.op_ref_reg(A_MOV,S_L,href,NR_EDI));
                    ungetcpuregister(list,NR_EDI);
                 end
             end
           else
{$endif NOTARGETWIN}
{$endif i386}
{$ifdef x86_64}
{$ifndef NOTARGETWIN}
           { windows guards only a few pages for stack growing,
             so we have to access every page first              }
           if (target_info.system=system_x86_64_win64) and
              (localsize>=winstackpagesize) then
             begin
               if localsize div winstackpagesize<=5 then
                 begin
                    list.concat(Taicpu.Op_const_reg(A_SUB,S_Q,localsize,NR_RSP));
                    for i:=1 to localsize div winstackpagesize do
                      begin
                         reference_reset_base(href,NR_RSP,localsize-i*winstackpagesize+4,4);
                         list.concat(Taicpu.op_reg_ref(A_MOV,S_L,NR_EAX,href));
                      end;
                    reference_reset_base(href,NR_RSP,0,4);
                    list.concat(Taicpu.op_reg_ref(A_MOV,S_L,NR_EAX,href));
                 end
               else
                 begin
                    current_asmdata.getjumplabel(again);
                    getcpuregister(list,NR_R10);
                    list.concat(Taicpu.op_const_reg(A_MOV,S_Q,localsize div winstackpagesize,NR_R10));
                    a_label(list,again);
                    list.concat(Taicpu.op_const_reg(A_SUB,S_Q,winstackpagesize,NR_RSP));
                    reference_reset_base(href,NR_RSP,0,4);
                    list.concat(Taicpu.op_reg_ref(A_MOV,S_L,NR_EAX,href));
                    list.concat(Taicpu.op_reg(A_DEC,S_Q,NR_R10));
                    a_jmp_cond(list,OC_NE,again);
                    list.concat(Taicpu.op_const_reg(A_SUB,S_Q,localsize mod winstackpagesize,NR_RSP));
                    ungetcpuregister(list,NR_R10);
                 end
             end
           else
{$endif NOTARGETWIN}
{$endif x86_64}
            list.concat(Taicpu.Op_const_reg(A_SUB,tcgsize2opsize[OS_ADDR],localsize,NR_STACK_POINTER_REG));
         end;
      end;


    procedure tcgx86.g_proc_entry(list : TAsmList;localsize : longint;nostackframe:boolean);
      var
        stackmisalignment: longint;
        para: tparavarsym;
      begin
{$ifdef i386}
        { interrupt support for i386 }
        if (po_interrupt in current_procinfo.procdef.procoptions) and
           { this messes up stack alignment }
           not(target_info.system in [system_i386_darwin,system_i386_iphonesim]) then
          begin
            { .... also the segment registers }
            list.concat(Taicpu.Op_reg(A_PUSH,S_W,NR_GS));
            list.concat(Taicpu.Op_reg(A_PUSH,S_W,NR_FS));
            list.concat(Taicpu.Op_reg(A_PUSH,S_W,NR_ES));
            list.concat(Taicpu.Op_reg(A_PUSH,S_W,NR_DS));
            { save the registers of an interrupt procedure }
            list.concat(Taicpu.Op_reg(A_PUSH,S_L,NR_EDI));
            list.concat(Taicpu.Op_reg(A_PUSH,S_L,NR_ESI));
            list.concat(Taicpu.Op_reg(A_PUSH,S_L,NR_EDX));
            list.concat(Taicpu.Op_reg(A_PUSH,S_L,NR_ECX));
            list.concat(Taicpu.Op_reg(A_PUSH,S_L,NR_EBX));
            list.concat(Taicpu.Op_reg(A_PUSH,S_L,NR_EAX));
          end;
{$endif i386}

        { save old framepointer }
        if not nostackframe then
          begin
            { return address }
            stackmisalignment := sizeof(pint);
            list.concat(tai_regalloc.alloc(current_procinfo.framepointer,nil));
            if current_procinfo.framepointer=NR_STACK_POINTER_REG then
              CGmessage(cg_d_stackframe_omited)
            else
              begin
                { push <frame_pointer> }
                inc(stackmisalignment,sizeof(pint));
                include(rg[R_INTREGISTER].preserved_by_proc,RS_FRAME_POINTER_REG);
                list.concat(Taicpu.op_reg(A_PUSH,tcgsize2opsize[OS_ADDR],NR_FRAME_POINTER_REG));
                if (target_info.system=system_x86_64_win64) then
                  begin
                    list.concat(cai_seh_directive.create_reg(ash_pushreg,NR_FRAME_POINTER_REG));
                    include(current_procinfo.flags,pi_has_unwind_info);
                  end;
                { Return address and FP are both on stack }
                current_asmdata.asmcfi.cfa_def_cfa_offset(list,2*sizeof(pint));
                current_asmdata.asmcfi.cfa_offset(list,NR_FRAME_POINTER_REG,-(2*sizeof(pint)));
                if current_procinfo.procdef.proctypeoption<>potype_exceptfilter then
                  list.concat(Taicpu.op_reg_reg(A_MOV,tcgsize2opsize[OS_ADDR],NR_STACK_POINTER_REG,NR_FRAME_POINTER_REG))
                else
                  begin
                    { load framepointer from hidden $parentfp parameter }
                    para:=tparavarsym(current_procinfo.procdef.paras[0]);
                    if not (vo_is_parentfp in para.varoptions) then
                      InternalError(201201142);
                    if (para.paraloc[calleeside].location^.loc<>LOC_REGISTER) or
                       (para.paraloc[calleeside].location^.next<>nil) then
                      InternalError(201201143);
                    list.concat(Taicpu.op_reg_reg(A_MOV,tcgsize2opsize[OS_ADDR],
                      para.paraloc[calleeside].location^.register,NR_FRAME_POINTER_REG));
                    { Need only as much stack space as necessary to do the calls.
                      Exception filters don't have own local vars, and temps are 'mapped'
                      to the parent procedure.
                      maxpushedparasize is already aligned at least on x86_64. }
                    localsize:=current_procinfo.maxpushedparasize;
                  end;
                current_asmdata.asmcfi.cfa_def_cfa_register(list,NR_FRAME_POINTER_REG);
                {
                  TODO: current framepointer handling is not compatible with Win64 at all:
                  Win64 expects FP to point to the top or into the middle of local area.
                  In FPC it points to the bottom, making it impossible to generate
                  UWOP_SET_FPREG unwind code if local area is > 240 bytes.
                  So for now pretend we never have a framepointer.
                }
              end;

            { allocate stackframe space }
            if (localsize<>0) or
               ((target_info.system in systems_need_16_byte_stack_alignment) and
                (stackmisalignment <> 0) and
                ((pi_do_call in current_procinfo.flags) or
                 (po_assembler in current_procinfo.procdef.procoptions))) then
              begin
                if (target_info.system in systems_need_16_byte_stack_alignment) then
                  localsize := align(localsize+stackmisalignment,16)-stackmisalignment;
                cg.g_stackpointer_alloc(list,localsize);
                if current_procinfo.framepointer=NR_STACK_POINTER_REG then
                  current_asmdata.asmcfi.cfa_def_cfa_offset(list,localsize+sizeof(pint));
                current_procinfo.final_localsize:=localsize;
                if (target_info.system=system_x86_64_win64) then
                  begin
                    if localsize<>0 then
                      list.concat(cai_seh_directive.create_offset(ash_stackalloc,localsize));
                    include(current_procinfo.flags,pi_has_unwind_info);
                  end;
              end;
          end;
      end;


    { produces if necessary overflowcode }
    procedure tcgx86.g_overflowcheck(list: TAsmList; const l:tlocation;def:tdef);
      var
         hl : tasmlabel;
         ai : taicpu;
         cond : TAsmCond;
      begin
         if not(cs_check_overflow in current_settings.localswitches) then
          exit;
         current_asmdata.getjumplabel(hl);
         if not ((def.typ=pointerdef) or
                ((def.typ=orddef) and
                 (torddef(def).ordtype in [u64bit,u16bit,u32bit,u8bit,uchar,
                                           pasbool8,pasbool16,pasbool32,pasbool64]))) then
           cond:=C_NO
         else
           cond:=C_NB;
         ai:=Taicpu.Op_Sym(A_Jcc,S_NO,hl);
         ai.SetCondition(cond);
         ai.is_jmp:=true;
         list.concat(ai);

         a_call_name(list,'FPC_OVERFLOW',false);
         a_label(list,hl);
      end;

    procedure tcgx86.g_external_wrapper(list: TAsmList; procdef: tprocdef; const externalname: string);
      var
        ref : treference;
        sym : tasmsymbol;
      begin
       if (target_info.system = system_i386_darwin) then
         begin
           { a_jmp_name jumps to a stub which is always pic-safe on darwin }
           inherited g_external_wrapper(list,procdef,externalname);
           exit;
         end;

        sym:=current_asmdata.RefAsmSymbol(externalname);
        reference_reset_symbol(ref,sym,0,sizeof(pint));

        { create pic'ed? }
        if (cs_create_pic in current_settings.moduleswitches) and
           { darwin/x86_64's assembler doesn't want @PLT after call symbols }
           not(target_info.system in [system_x86_64_darwin,system_i386_iphonesim]) then
          ref.refaddr:=addr_pic
        else
          ref.refaddr:=addr_full;
        list.concat(taicpu.op_ref(A_JMP,S_NO,ref));
      end;

end.