fpc/compiler/aarch64/aasmcpu.pas

{
    Copyright (c) 2003-2012 by Florian Klaempfl and others

    Contains the assembler object for ARM64

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 ****************************************************************************
}
unit aasmcpu;

{$i fpcdefs.inc}

interface

uses
  cclasses,globtype,globals,verbose,
  aasmbase,aasmtai,aasmdata,aasmsym,
  ogbase,
  symtype,
  cpubase,cpuinfo,cgbase,cgutils;

    const
      { "mov reg,reg" source operand number }
      O_MOV_SOURCE = 1;
      { "mov reg,reg" source operand number }
      O_MOV_DEST = 0;

      { Operand types }
      OT_NONE      = $00000000;

      OT_BITS8     = $00000001;  { size, and other attributes, of the operand  }
      OT_BITS16    = $00000002;
      OT_BITS32    = $00000004;
      OT_BITS64    = $00000008;  { FPU only  }
      OT_BITS80    = $00000010;
      OT_FAR       = $00000020;  { this means 16:16 or 16:32, like in CALL/JMP }
      OT_NEAR      = $00000040;
      OT_SHORT     = $00000080;
      OT_BITSTINY  = $00000100;  { fpu constant }
      OT_BITSSHIFTER =
                     $00000200;

      OT_SIZE_MASK = $000003FF;  { all the size attributes  }
      OT_NON_SIZE  = longint(not OT_SIZE_MASK);

      OT_SIGNED    = $00000100;  { the operand need to be signed -128-127 }

      OT_TO        = $00000200;  { operand is followed by a colon  }
                                 { reverse effect in FADD, FSUB &c  }
      OT_COLON     = $00000400;

      OT_SHIFTEROP = $00000800;
      OT_REGISTER  = $00001000;
      OT_IMMEDIATE = $00002000;
      OT_REGLIST   = $00008000;
      OT_IMM8      = $00002001;
      OT_IMM24     = $00002002;
      OT_IMM32     = $00002004;
      OT_IMM64     = $00002008;
      OT_IMM80     = $00002010;
      OT_IMMTINY   = $00002100;
      OT_IMMSHIFTER= $00002200;
      OT_IMMEDIATE24 = OT_IMM24;
      OT_SHIFTIMM  = OT_SHIFTEROP or OT_IMMSHIFTER;
      OT_SHIFTIMMEDIATE = OT_SHIFTIMM;
      OT_IMMEDIATESHIFTER = OT_IMMSHIFTER;

      OT_IMMEDIATEFPU = OT_IMMTINY;

      OT_REGMEM    = $00200000;  { for r/m, ie EA, operands  }
      OT_REGNORM   = $00201000;  { 'normal' reg, qualifies as EA  }
      OT_REG8      = $00201001;
      OT_REG16     = $00201002;
      OT_REG32     = $00201004;
      OT_REG64     = $00201008;
      OT_VREG      = $00201010;  { vector register }
      OT_REGF      = $00201020;  { coproc register }
      OT_MEMORY    = $00204000;  { register number in 'basereg'  }
      OT_MEM8      = $00204001;
      OT_MEM16     = $00204002;
      OT_MEM32     = $00204004;
      OT_MEM64     = $00204008;
      OT_MEM80     = $00204010;
      { word/byte load/store }
      OT_AM2       = $00010000;
      { misc ld/st operations }
      OT_AM3       = $00020000;
      { multiple ld/st operations }
      OT_AM4       = $00040000;
      { co proc. ld/st operations }
      OT_AM5       = $00080000;
      OT_AMMASK    = $000f0000;
      { IT instruction }
      OT_CONDITION = $00100000;

      OT_MEMORYAM2 = OT_MEMORY or OT_AM2;
      OT_MEMORYAM3 = OT_MEMORY or OT_AM3;
      OT_MEMORYAM4 = OT_MEMORY or OT_AM4;
      OT_MEMORYAM5 = OT_MEMORY or OT_AM5;

      OT_FPUREG    = $01000000;  { floating point stack registers  }
      OT_REG_SMASK = $00070000;  { special register operands: these may be treated differently  }
                                 { a mask for the following  }

      OT_MEM_OFFS  = $00604000;  { special type of EA  }
                                 { simple [address] offset  }
      OT_ONENESS   = $00800000;  { special type of immediate operand  }
                                 { so UNITY == IMMEDIATE | ONENESS  }
      OT_UNITY     = $00802000;  { for shift/rotate instructions  }

      instabentries = {$i a64nop.inc}

      maxinfolen = 5;

      IF_NONE   = $00000000;

      IF_ARMMASK    = $000F0000;
      IF_ARM7       = $00070000;
      IF_FPMASK     = $00F00000;
      IF_FPA        = $00100000;

      { if the instruction can change in a second pass }
      IF_PASS2  = longint($80000000);

    type
      TInsTabCache=array[TasmOp] of longint;
      PInsTabCache=^TInsTabCache;

      tinsentry = record
        opcode  : tasmop;
        ops     : byte;
        optypes : array[0..3] of longint;
        code    : array[0..maxinfolen] of char;
        flags   : longint;
      end;

      pinsentry=^tinsentry;

    var
      InsTabCache : PInsTabCache;

    type
      taicpu = class(tai_cpu_abstract_sym)
         oppostfix : TOpPostfix;
         procedure loadshifterop(opidx:longint;const so:tshifterop);
         constructor op_none(op : tasmop);

         constructor op_reg(op : tasmop;_op1 : tregister);
         constructor op_ref(op : tasmop;const _op1 : treference);
         constructor op_const(op : tasmop;_op1 : longint);

         constructor op_reg_reg(op : tasmop;_op1,_op2 : tregister);
         constructor op_reg_ref(op : tasmop;_op1 : tregister;const _op2 : treference);
         constructor op_reg_const(op:tasmop; _op1: tregister; _op2: aint);
         constructor op_reg_const_shifterop(op : tasmop;_op1: tregister; _op2: aint;_op3 : tshifterop);

         constructor op_reg_reg_reg(op : tasmop;_op1,_op2,_op3 : tregister);
         constructor op_reg_reg_reg_reg(op : tasmop;_op1,_op2,_op3,_op4 : tregister);
         constructor op_reg_reg_const(op : tasmop;_op1,_op2 : tregister; _op3: aint);
         constructor op_reg_reg_const_shifterop(op : tasmop;_op1,_op2 : tregister; _op3: aint; const _op4 : tshifterop);
         constructor op_reg_reg_sym_ofs(op : tasmop;_op1,_op2 : tregister; _op3: tasmsymbol;_op3ofs: longint);
         constructor op_reg_reg_ref(op : tasmop;_op1,_op2 : tregister; const _op3: treference);
         constructor op_reg_reg_shifterop(op : tasmop;_op1,_op2 : tregister;_op3 : tshifterop);
         constructor op_reg_reg_reg_shifterop(op : tasmop;_op1,_op2,_op3 : tregister; const _op4 : tshifterop);

         { this is for Jmp instructions }
         constructor op_cond_sym(op : tasmop;cond:TAsmCond;_op1 : tasmsymbol);

         constructor op_sym(op : tasmop;_op1 : tasmsymbol);
         constructor op_sym_ofs(op : tasmop;_op1 : tasmsymbol;_op1ofs:longint);
         constructor op_reg_sym_ofs(op : tasmop;_op1 : tregister;_op2:tasmsymbol;_op2ofs : longint);
         constructor op_sym_ofs_ref(op : tasmop;_op1 : tasmsymbol;_op1ofs:longint;const _op2 : treference);

         function is_same_reg_move(regtype: Tregistertype):boolean; override;

         function spilling_get_operation_type(opnr: longint): topertype;override;

         { assembler }
      public
         { the next will reset all instructions that can change in pass 2 }
         procedure ResetPass1;override;
         procedure ResetPass2;override;
         function  CheckIfValid:boolean;
         function GetString:string;
         function  Pass1(objdata:TObjData):longint;override;
         procedure Pass2(objdata:TObjData);override;
      protected
         procedure ppuloadoper(ppufile:tcompilerppufile;var o:toper);override;
         procedure ppuwriteoper(ppufile:tcompilerppufile;const o:toper);override;
         procedure ppubuildderefimploper(var o:toper);override;
         procedure ppuderefoper(var o:toper);override;
      private
         { next fields are filled in pass1, so pass2 is faster }
         inssize   : shortint;
         insoffset : longint;
         LastInsOffset : longint; { need to be public to be reset }
         insentry  : PInsEntry;
         function  InsEnd:longint;
         procedure create_ot(objdata:TObjData);
         function  Matches(p:PInsEntry):longint;
         function  calcsize(p:PInsEntry):shortint;
         procedure gencode(objdata:TObjData);
         function  NeedAddrPrefix(opidx:byte):boolean;
         procedure Swapoperands;
         function  FindInsentry(objdata:TObjData):boolean;
      end;

      tai_align = class(tai_align_abstract)
        { nothing to add }
      end;

    function spilling_create_load(const ref: treference; r: tregister): taicpu;
    function spilling_create_store(r: tregister; const ref: treference): taicpu;

    function setoppostfix(i : taicpu;pf : toppostfix) : taicpu;
    function setcondition(i : taicpu;c : tasmcond) : taicpu;

    { inserts pc relative symbols at places where they are reachable
      and transforms special instructions to valid instruction encodings }
    procedure finalizearmcode(list,listtoinsert : TAsmList);
    { inserts .pdata section and dummy function prolog needed for arm-wince exception handling }
    procedure InsertPData;

    procedure InitAsm;
    procedure DoneAsm;


implementation

  uses
    cutils,rgobj,itcpugas,aoptcpu;


    procedure taicpu.loadshifterop(opidx:longint;const so:tshifterop);
      begin
        allocate_oper(opidx+1);
        with oper[opidx]^ do
          begin
            if typ<>top_shifterop then
              begin
                clearop(opidx);
                new(shifterop);
              end;
            shifterop^:=so;
            typ:=top_shifterop;
          end;
      end;


{*****************************************************************************
                                 taicpu Constructors
*****************************************************************************}

    constructor taicpu.op_none(op : tasmop);
      begin
         inherited create(op);
      end;


    { for pld }
    constructor taicpu.op_ref(op : tasmop;const _op1 : treference);
      begin
         inherited create(op);
         ops:=1;
         loadref(0,_op1);
      end;


    constructor taicpu.op_reg(op : tasmop;_op1 : tregister);
      begin
         inherited create(op);
         ops:=1;
         loadreg(0,_op1);
      end;


    constructor taicpu.op_const(op : tasmop;_op1 : longint);
      begin
         inherited create(op);
         ops:=1;
         loadconst(0,aint(_op1));
      end;


    constructor taicpu.op_reg_reg(op : tasmop;_op1,_op2 : tregister);
      begin
         inherited create(op);
         ops:=2;
         loadreg(0,_op1);
         loadreg(1,_op2);
      end;


    constructor taicpu.op_reg_const(op:tasmop; _op1: tregister; _op2: aint);
      begin
         inherited create(op);
         ops:=2;
         loadreg(0,_op1);
         loadconst(1,aint(_op2));
      end;


    constructor taicpu.op_reg_const_shifterop(op: tasmop; _op1: tregister; _op2: aint; _op3: tshifterop);
      begin
        inherited create(op);
        ops:=3;
        loadreg(0,_op1);
        loadconst(1,_op2);
        loadshifterop(2,_op3);
      end;


    constructor taicpu.op_reg_ref(op : tasmop;_op1 : tregister;const _op2 : treference);
      begin
         inherited create(op);
         ops:=2;
         loadreg(0,_op1);
         loadref(1,_op2);
      end;


    constructor taicpu.op_reg_reg_reg(op : tasmop;_op1,_op2,_op3 : tregister);
      begin
         inherited create(op);
         ops:=3;
         loadreg(0,_op1);
         loadreg(1,_op2);
         loadreg(2,_op3);
      end;


    constructor taicpu.op_reg_reg_reg_reg(op : tasmop;_op1,_op2,_op3,_op4 : tregister);
      begin
         inherited create(op);
         ops:=4;
         loadreg(0,_op1);
         loadreg(1,_op2);
         loadreg(2,_op3);
         loadreg(3,_op4);
      end;


     constructor taicpu.op_reg_reg_const(op : tasmop;_op1,_op2 : tregister; _op3: aint);
       begin
         inherited create(op);
         ops:=3;
         loadreg(0,_op1);
         loadreg(1,_op2);
         loadconst(2,aint(_op3));
      end;


     constructor taicpu.op_reg_reg_const_shifterop(op: tasmop; _op1, _op2: tregister; _op3: aint; const _op4: tshifterop);
       begin
         inherited create(op);
         ops:=4;
         loadreg(0,_op1);
         loadreg(1,_op2);
         loadconst(2,aint(_op3));
         loadshifterop(3,_op4);
       end;


     constructor taicpu.op_reg_reg_sym_ofs(op : tasmop;_op1,_op2 : tregister; _op3: tasmsymbol;_op3ofs: longint);
       begin
         inherited create(op);
         ops:=3;
         loadreg(0,_op1);
         loadreg(1,_op2);
         loadsymbol(0,_op3,_op3ofs);
      end;


     constructor taicpu.op_reg_reg_ref(op : tasmop;_op1,_op2 : tregister; const _op3: treference);
       begin
         inherited create(op);
         ops:=3;
         loadreg(0,_op1);
         loadreg(1,_op2);
         loadref(2,_op3);
      end;


     constructor taicpu.op_reg_reg_shifterop(op : tasmop;_op1,_op2 : tregister;_op3 : tshifterop);
      begin
         inherited create(op);
         ops:=3;
         loadreg(0,_op1);
         loadreg(1,_op2);
         loadshifterop(2,_op3);
      end;


     constructor taicpu.op_reg_reg_reg_shifterop(op : tasmop;_op1,_op2,_op3 : tregister; const _op4 : tshifterop);
      begin
         inherited create(op);
         ops:=4;
         loadreg(0,_op1);
         loadreg(1,_op2);
         loadreg(2,_op3);
         loadshifterop(3,_op4);
      end;


    constructor taicpu.op_cond_sym(op : tasmop;cond:TAsmCond;_op1 : tasmsymbol);
      begin
         inherited create(op);
         condition:=cond;
         ops:=1;
         loadsymbol(0,_op1,0);
      end;


    constructor taicpu.op_sym(op : tasmop;_op1 : tasmsymbol);
      begin
         inherited create(op);
         ops:=1;
         loadsymbol(0,_op1,0);
      end;


    constructor taicpu.op_sym_ofs(op : tasmop;_op1 : tasmsymbol;_op1ofs:longint);
      begin
         inherited create(op);
         ops:=1;
         loadsymbol(0,_op1,_op1ofs);
      end;


     constructor taicpu.op_reg_sym_ofs(op : tasmop;_op1 : tregister;_op2:tasmsymbol;_op2ofs : longint);
      begin
         inherited create(op);
         ops:=2;
         loadreg(0,_op1);
         loadsymbol(1,_op2,_op2ofs);
      end;


    constructor taicpu.op_sym_ofs_ref(op : tasmop;_op1 : tasmsymbol;_op1ofs:longint;const _op2 : treference);
      begin
         inherited create(op);
         ops:=2;
         loadsymbol(0,_op1,_op1ofs);
         loadref(1,_op2);
      end;


    function taicpu.is_same_reg_move(regtype: Tregistertype):boolean;
      begin
        { allow the register allocator to remove unnecessary moves }
        result:=(
                  ((opcode=A_MOV) and (regtype = R_INTREGISTER)) or
                  ((opcode=A_FMOV) and (regtype = R_MMREGISTER))
                ) and
                (oppostfix in [PF_None]) and
                (condition=C_None) and
                (ops=2) and
                (oper[0]^.typ=top_reg) and
                (oper[1]^.typ=top_reg) and
                (oper[0]^.reg=oper[1]^.reg);
      end;


    function spilling_create_op(op: tasmop; const ref: treference; r: tregister): taicpu;
      const
        { invalid sizes for aarch64 are 0 }
        subreg2bytesize: array[TSubRegister] of byte =
          (0,0,0,0,4,8,0,0,0,4,8,0,0,0);
      var
        scalefactor: byte;
      begin
        scalefactor:=subreg2bytesize[getsubreg(r)];
        if scalefactor=0 then
          internalerror(2014120301);
        if (ref.offset>4095*scalefactor) or
           ((ref.offset>255) and
            ((ref.offset mod scalefactor)<>0)) or
           (ref.offset<-256) then
          internalerror(2014120302);
        case getregtype(r) of
          R_INTREGISTER,
          R_MMREGISTER:
            result:=taicpu.op_reg_ref(op,r,ref);
          else
            internalerror(200401041);
        end;
      end;


    function spilling_create_load(const ref: treference; r: tregister): taicpu;
      var
        op: tasmop;
      begin
        if (ref.index<>NR_NO) or
           (ref.offset<-256) or
           (ref.offset>255) then
          op:=A_LDR
        else
          op:=A_LDUR;
        result:=spilling_create_op(op,ref,r);
      end;


    function spilling_create_store(r: tregister; const ref: treference): taicpu;
      var
        op: tasmop;
      begin
        if (ref.index<>NR_NO) or
           (ref.offset<-256) or
           (ref.offset>255) then
          op:=A_STR
        else
          op:=A_STUR;
        result:=spilling_create_op(op,ref,r);
      end;


    function taicpu.spilling_get_operation_type(opnr: longint): topertype;
      begin
        case opcode of
          A_ADC,A_ADD,A_AND,A_BIC,
          A_EOR,A_CLZ,A_RBIT,
          A_LDR,
          A_MOV,A_MVN,A_MUL,
          A_ORR,A_SBC,A_SUB,
          A_UXT,A_SXT:
            if opnr=0 then
              result:=operand_write
            else
              result:=operand_read;
          A_B,A_BL,
          A_CMN,A_CMP,A_TST:
            result:=operand_read;
          A_STR:
            { important is what happens with the involved registers }
            if opnr=0 then
              result := operand_read
            else
              { check for pre/post indexed }
              result := operand_read;
          else
            internalerror(200403151);
        end;
      end;


    procedure BuildInsTabCache;
      var
        i : longint;
      begin
(*        new(instabcache);
        FillChar(instabcache^,sizeof(tinstabcache),$ff);
        i:=0;
        while (i<InsTabEntries) do
          begin
            if InsTabCache^[InsTab[i].Opcode]=-1 then
              InsTabCache^[InsTab[i].Opcode]:=i;
            inc(i);
          end; *)
      end;


    procedure InitAsm;
      begin
        if not assigned(instabcache) then
          BuildInsTabCache;
      end;


    procedure DoneAsm;
      begin
        if assigned(instabcache) then
          begin
            dispose(instabcache);
            instabcache:=nil;
          end;
      end;


    function setoppostfix(i : taicpu;pf : toppostfix) : taicpu;
      begin
        i.oppostfix:=pf;
        result:=i;
      end;


    function setcondition(i : taicpu;c : tasmcond) : taicpu;
      begin
        i.condition:=c;
        result:=i;
      end;


    Function SimpleGetNextInstruction(Current: tai; Var Next: tai): Boolean;
      Begin
        Current:=tai(Current.Next);
        While Assigned(Current) And (Current.typ In SkipInstr) Do
          Current:=tai(Current.Next);
        Next:=Current;
        If Assigned(Next) And Not(Next.typ In SkipInstr) Then
           Result:=True
          Else
            Begin
              Next:=Nil;
              Result:=False;
            End;
      End;


(*
    function armconstequal(hp1,hp2: tai): boolean;
      begin
        result:=false;
        if hp1.typ<>hp2.typ then
          exit;
        case hp1.typ of
          tai_const:
            result:=
              (tai_const(hp2).sym=tai_const(hp).sym) and
              (tai_const(hp2).value=tai_const(hp).value) and
              (tai(hp2.previous).typ=ait_label);
            tai_const:
              result:=
                (tai_const(hp2).sym=tai_const(hp).sym) and
                (tai_const(hp2).value=tai_const(hp).value) and
                (tai(hp2.previous).typ=ait_label);
        end;
      end;
*)

    procedure insertpcrelativedata(list,listtoinsert : TAsmList);
      var
        curinspos,
        penalty,
        lastinspos,
        { increased for every data element > 4 bytes inserted }
        currentsize,
        extradataoffset,
        limit: longint;
        curop : longint;
        curtai : tai;
        curdatatai,hp,hp2 : tai;
        curdata : TAsmList;
        l : tasmlabel;
        doinsert,
        removeref : boolean;
      begin
(*
        curdata:=TAsmList.create;
        lastinspos:=-1;
        curinspos:=0;
        extradataoffset:=0;
        limit:=1016;
        curtai:=tai(list.first);
        doinsert:=false;
        while assigned(curtai) do
          begin
            { instruction? }
            case curtai.typ of
              ait_instruction:
                begin
                  { walk through all operand of the instruction }
                  for curop:=0 to taicpu(curtai).ops-1 do
                    begin
                      { reference? }
                      if (taicpu(curtai).oper[curop]^.typ=top_ref) then
                        begin
                          { pc relative symbol? }
                          curdatatai:=tai(taicpu(curtai).oper[curop]^.ref^.symboldata);
                          if assigned(curdatatai) and
                            { move only if we're at the first reference of a label }
                            not(tai_label(curdatatai).moved) then
                            begin
                              tai_label(curdatatai).moved:=true;
                              { check if symbol already used. }
                              { if yes, reuse the symbol }
                              hp:=tai(curdatatai.next);
                              removeref:=false;
                              if assigned(hp) then
                                begin
                                  case hp.typ of
                                    ait_const:
                                      begin
                                        if (tai_const(hp).consttype=aitconst_64bit) then
                                          inc(extradataoffset);
                                      end;
                                    ait_comp_64bit,
                                    ait_real_64bit:
                                      begin
                                        inc(extradataoffset);
                                      end;
                                    ait_real_80bit:
                                      begin
                                        inc(extradataoffset,2);
                                      end;
                                  end;
                                  if (hp.typ=ait_const) then
                                    begin
                                      hp2:=tai(curdata.first);
                                      while assigned(hp2) do
                                        begin
    {                                      if armconstequal(hp2,hp) then }
                                          if (hp2.typ=ait_const) and (tai_const(hp2).sym=tai_const(hp).sym)
                                            and (tai_const(hp2).value=tai_const(hp).value) and (tai(hp2.previous).typ=ait_label)
                                          then
                                            begin
                                              with taicpu(curtai).oper[curop]^.ref^ do
                                                begin
                                                  symboldata:=hp2.previous;
                                                  symbol:=tai_label(hp2.previous).labsym;
                                                end;
                                              removeref:=true;
                                              break;
                                            end;
                                          hp2:=tai(hp2.next);
                                        end;
                                    end;
                                end;
                              { move or remove symbol reference }
                              repeat
                                hp:=tai(curdatatai.next);
                                listtoinsert.remove(curdatatai);
                                if removeref then
                                  curdatatai.free
                                else
                                  curdata.concat(curdatatai);
                                curdatatai:=hp;
                              until (curdatatai=nil) or (curdatatai.typ=ait_label);
                              if lastinspos=-1 then
                                lastinspos:=curinspos;
                            end;
                        end;
                    end;
                  inc(curinspos);
                end;
              ait_align:
                begin
                  { code is always 4 byte aligned, so we don't have to take care of .align 2 which would
                    requires also incrementing curinspos by 1 }
                  inc(curinspos,(tai_align(curtai).aligntype div 4));
                end;
              ait_const:
                begin
                  inc(curinspos);
                  if (tai_const(curtai).consttype=aitconst_64bit) then
                    inc(curinspos);
                end;
              ait_real_32bit:
                begin
                  inc(curinspos);
                end;
              ait_comp_64bit,
              ait_real_64bit:
                begin
                  inc(curinspos,2);
                end;
              ait_real_80bit:
                begin
                  inc(curinspos,3);
                end;
            end;
            { special case for case jump tables }
            if SimpleGetNextInstruction(curtai,hp) and
              (tai(hp).typ=ait_instruction) and
              (taicpu(hp).opcode=A_LDR) and
              (taicpu(hp).oper[0]^.typ=top_reg) and
              (taicpu(hp).oper[0]^.reg=NR_PC) then
              begin
                penalty:=1;
                hp:=tai(hp.next);
                { skip register allocations and comments inserted by the optimizer }
                while assigned(hp) and (hp.typ in [ait_comment,ait_regalloc]) do
                  hp:=tai(hp.next);
                while assigned(hp) and (hp.typ=ait_const) do
                  begin
                    inc(penalty);
                    hp:=tai(hp.next);
                  end;
              end
            else
              penalty:=0;

            { FLD/FST VFP instructions have a limit of +/- 1024, not 4096 }
            if SimpleGetNextInstruction(curtai,hp) and
               (tai(hp).typ=ait_instruction) and
               ((taicpu(hp).opcode=A_FLDS) or
                (taicpu(hp).opcode=A_FLDD)) then
              limit:=254;

            { don't miss an insert }
            doinsert:=doinsert or
              (not(curdata.empty) and
               (curinspos-lastinspos+penalty+extradataoffset>limit));

            { split only at real instructions else the test below fails }
            if doinsert and (curtai.typ=ait_instruction) and
              (
                { don't split loads of pc to lr and the following move }
                not(
                    (taicpu(curtai).opcode=A_MOV) and
                    (taicpu(curtai).oper[0]^.typ=top_reg) and
                    (taicpu(curtai).oper[0]^.reg=NR_R14) and
                    (taicpu(curtai).oper[1]^.typ=top_reg) and
                    (taicpu(curtai).oper[1]^.reg=NR_PC)
                   )
              ) then
              begin
                lastinspos:=-1;
                extradataoffset:=0;
                limit:=1016;
                doinsert:=false;
                hp:=tai(curtai.next);
                current_asmdata.getjumplabel(l);
                curdata.insert(taicpu.op_sym(A_B,l));
                curdata.concat(tai_label.create(l));
                list.insertlistafter(curtai,curdata);
                curtai:=hp;
              end
            else
              curtai:=tai(curtai.next);
          end;
        list.concatlist(curdata);
        curdata.free;
*)
      end;


    procedure finalizearmcode(list, listtoinsert: TAsmList);
      begin
        insertpcrelativedata(list, listtoinsert);
      end;

    procedure InsertPData;
      var
        prolog: TAsmList;
      begin
        prolog:=TAsmList.create;
        new_section(prolog,sec_code,'FPC_EH_PROLOG',sizeof(pint),secorder_begin);
        prolog.concat(Tai_const.Createname('_ARM_ExceptionHandler', 0));
        prolog.concat(Tai_const.Create_32bit(0));
        prolog.concat(Tai_symbol.Createname_global('FPC_EH_CODE_START',AT_DATA,0));
        { dummy function }
        prolog.concat(taicpu.op_reg(A_BR,NR_X29));
        current_asmdata.asmlists[al_start].insertList(prolog);
        prolog.Free;
        new_section(current_asmdata.asmlists[al_end],sec_pdata,'',sizeof(pint));
        current_asmdata.asmlists[al_end].concat(Tai_const.Createname('FPC_EH_CODE_START', 0));
        current_asmdata.asmlists[al_end].concat(Tai_const.Create_32bit(longint($ffffff01)));
      end;

(*
      Floating point instruction format information, taken from the linux kernel
      ARM Floating Point Instruction Classes
      | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
      |c o n d|1 1 0 P|U|u|W|L|   Rn  |v|  Fd |0|0|0|1|  o f f s e t  | CPDT
      |c o n d|1 1 0 P|U|w|W|L|   Rn  |x|  Fd |0|0|1|0|  o f f s e t  | CPDT (copro 2)
      | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
      |c o n d|1 1 1 0|a|b|c|d|e|  Fn |j|  Fd |0|0|0|1|f|g|h|0|i|  Fm | CPDO
      |c o n d|1 1 1 0|a|b|c|L|e|  Fn |   Rd  |0|0|0|1|f|g|h|1|i|  Fm | CPRT
      |c o n d|1 1 1 0|a|b|c|1|e|  Fn |1|1|1|1|0|0|0|1|f|g|h|1|i|  Fm | comparisons
      | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

      CPDT            data transfer instructions
                      LDF, STF, LFM (copro 2), SFM (copro 2)

      CPDO            dyadic arithmetic instructions
                      ADF, MUF, SUF, RSF, DVF, RDF,
                      POW, RPW, RMF, FML, FDV, FRD, POL

      CPDO            monadic arithmetic instructions
                      MVF, MNF, ABS, RND, SQT, LOG, LGN, EXP,
                      SIN, COS, TAN, ASN, ACS, ATN, URD, NRM

      CPRT            joint arithmetic/data transfer instructions
                      FIX (arithmetic followed by load/store)
                      FLT (load/store followed by arithmetic)
                      CMF, CNF CMFE, CNFE (comparisons)
                      WFS, RFS (write/read floating point status register)
                      WFC, RFC (write/read floating point control register)

      cond            condition codes
      P               pre/post index bit: 0 = postindex, 1 = preindex
      U               up/down bit: 0 = stack grows down, 1 = stack grows up
      W               write back bit: 1 = update base register (Rn)
      L               load/store bit: 0 = store, 1 = load
      Rn              base register
      Rd              destination/source register
      Fd              floating point destination register
      Fn              floating point source register
      Fm              floating point source register or floating point constant

      uv              transfer length (TABLE 1)
      wx              register count (TABLE 2)
      abcd            arithmetic opcode (TABLES 3 & 4)
      ef              destination size (rounding precision) (TABLE 5)
      gh              rounding mode (TABLE 6)
      j               dyadic/monadic bit: 0 = dyadic, 1 = monadic
      i               constant bit: 1 = constant (TABLE 6)
      */

      /*
      TABLE 1
      +-------------------------+---+---+---------+---------+
      |  Precision              | u | v | FPSR.EP | length  |
      +-------------------------+---+---+---------+---------+
      | Single                  | 0 | 0 |    x    | 1 words |
      | Double                  | 1 | 1 |    x    | 2 words |
      | Extended                | 1 | 1 |    x    | 3 words |
      | Packed decimal          | 1 | 1 |    0    | 3 words |
      | Expanded packed decimal | 1 | 1 |    1    | 4 words |
      +-------------------------+---+---+---------+---------+
      Note: x = don't care
      */

      /*
      TABLE 2
      +---+---+---------------------------------+
      | w | x | Number of registers to transfer |
      +---+---+---------------------------------+
      | 0 | 1 |  1                              |
      | 1 | 0 |  2                              |
      | 1 | 1 |  3                              |
      | 0 | 0 |  4                              |
      +---+---+---------------------------------+
      */

      /*
      TABLE 3: Dyadic Floating Point Opcodes
      +---+---+---+---+----------+-----------------------+-----------------------+
      | a | b | c | d | Mnemonic | Description           | Operation             |
      +---+---+---+---+----------+-----------------------+-----------------------+
      | 0 | 0 | 0 | 0 | ADF      | Add                   | Fd := Fn + Fm         |
      | 0 | 0 | 0 | 1 | MUF      | Multiply              | Fd := Fn * Fm         |
      | 0 | 0 | 1 | 0 | SUF      | Subtract              | Fd := Fn - Fm         |
      | 0 | 0 | 1 | 1 | RSF      | Reverse subtract      | Fd := Fm - Fn         |
      | 0 | 1 | 0 | 0 | DVF      | Divide                | Fd := Fn / Fm         |
      | 0 | 1 | 0 | 1 | RDF      | Reverse divide        | Fd := Fm / Fn         |
      | 0 | 1 | 1 | 0 | POW      | Power                 | Fd := Fn ^ Fm         |
      | 0 | 1 | 1 | 1 | RPW      | Reverse power         | Fd := Fm ^ Fn         |
      | 1 | 0 | 0 | 0 | RMF      | Remainder             | Fd := IEEE rem(Fn/Fm) |
      | 1 | 0 | 0 | 1 | FML      | Fast Multiply         | Fd := Fn * Fm         |
      | 1 | 0 | 1 | 0 | FDV      | Fast Divide           | Fd := Fn / Fm         |
      | 1 | 0 | 1 | 1 | FRD      | Fast reverse divide   | Fd := Fm / Fn         |
      | 1 | 1 | 0 | 0 | POL      | Polar angle (ArcTan2) | Fd := arctan2(Fn,Fm)  |
      | 1 | 1 | 0 | 1 |          | undefined instruction | trap                  |
      | 1 | 1 | 1 | 0 |          | undefined instruction | trap                  |
      | 1 | 1 | 1 | 1 |          | undefined instruction | trap                  |
      +---+---+---+---+----------+-----------------------+-----------------------+
      Note: POW, RPW, POL are deprecated, and are available for backwards
            compatibility only.
      */

      /*
      TABLE 4: Monadic Floating Point Opcodes
      +---+---+---+---+----------+-----------------------+-----------------------+
      | a | b | c | d | Mnemonic | Description           | Operation             |
      +---+---+---+---+----------+-----------------------+-----------------------+
      | 0 | 0 | 0 | 0 | MVF      | Move                  | Fd := Fm              |
      | 0 | 0 | 0 | 1 | MNF      | Move negated          | Fd := - Fm            |
      | 0 | 0 | 1 | 0 | ABS      | Absolute value        | Fd := abs(Fm)         |
      | 0 | 0 | 1 | 1 | RND      | Round to integer      | Fd := int(Fm)         |
      | 0 | 1 | 0 | 0 | SQT      | Square root           | Fd := sqrt(Fm)        |
      | 0 | 1 | 0 | 1 | LOG      | Log base 10           | Fd := log10(Fm)       |
      | 0 | 1 | 1 | 0 | LGN      | Log base e            | Fd := ln(Fm)          |
      | 0 | 1 | 1 | 1 | EXP      | Exponent              | Fd := e ^ Fm          |
      | 1 | 0 | 0 | 0 | SIN      | Sine                  | Fd := sin(Fm)         |
      | 1 | 0 | 0 | 1 | COS      | Cosine                | Fd := cos(Fm)         |
      | 1 | 0 | 1 | 0 | TAN      | Tangent               | Fd := tan(Fm)         |
      | 1 | 0 | 1 | 1 | ASN      | Arc Sine              | Fd := arcsin(Fm)      |
      | 1 | 1 | 0 | 0 | ACS      | Arc Cosine            | Fd := arccos(Fm)      |
      | 1 | 1 | 0 | 1 | ATN      | Arc Tangent           | Fd := arctan(Fm)      |
      | 1 | 1 | 1 | 0 | URD      | Unnormalized round    | Fd := int(Fm)         |
      | 1 | 1 | 1 | 1 | NRM      | Normalize             | Fd := norm(Fm)        |
      +---+---+---+---+----------+-----------------------+-----------------------+
      Note: LOG, LGN, EXP, SIN, COS, TAN, ASN, ACS, ATN are deprecated, and are
            available for backwards compatibility only.
      */

      /*
      TABLE 5
      +-------------------------+---+---+
      |  Rounding Precision     | e | f |
      +-------------------------+---+---+
      | IEEE Single precision   | 0 | 0 |
      | IEEE Double precision   | 0 | 1 |
      | IEEE Extended precision | 1 | 0 |
      | undefined (trap)        | 1 | 1 |
      +-------------------------+---+---+
      */

      /*
      TABLE 5
      +---------------------------------+---+---+
      |  Rounding Mode                  | g | h |
      +---------------------------------+---+---+
      | Round to nearest (default)      | 0 | 0 |
      | Round toward plus infinity      | 0 | 1 |
      | Round toward negative infinity  | 1 | 0 |
      | Round toward zero               | 1 | 1 |
      +---------------------------------+---+---+
*)
    function taicpu.GetString:string;
      var
        i : longint;
        s : string;
        addsize : boolean;
      begin
        s:='['+gas_op2str[opcode];
        for i:=0 to ops-1 do
         begin
           with oper[i]^ do
             begin
               if i=0 then
                s:=s+' '
               else
                s:=s+',';
               { type }
               addsize:=false;
               if (ot and OT_VREG)=OT_VREG then
                s:=s+'vreg'
               else
                 if (ot and OT_FPUREG)=OT_FPUREG then
                  s:=s+'fpureg'
               else
                if (ot and OT_REGISTER)=OT_REGISTER then
                 begin
                   s:=s+'reg';
                   addsize:=true;
                 end
               else
                if (ot and OT_REGLIST)=OT_REGLIST then
                 begin
                   s:=s+'reglist';
                   addsize:=false;
                 end
               else
                if (ot and OT_IMMEDIATE)=OT_IMMEDIATE then
                 begin
                   s:=s+'imm';
                   addsize:=true;
                 end
               else
                if (ot and OT_MEMORY)=OT_MEMORY then
                 begin
                   s:=s+'mem';
                   addsize:=true;
                   if (ot and OT_AM2)<>0 then
                     s:=s+' am2 ';
                 end
               else
                 s:=s+'???';
               { size }
               if addsize then
                begin
                  if (ot and OT_BITS8)<>0 then
                    s:=s+'8'
                  else
                   if (ot and OT_BITS16)<>0 then
                    s:=s+'24'
                  else
                   if (ot and OT_BITS32)<>0 then
                    s:=s+'32'
                  else
                   if (ot and OT_BITSSHIFTER)<>0 then
                    s:=s+'shifter'
                  else
                    s:=s+'??';
                  { signed }
                  if (ot and OT_SIGNED)<>0 then
                   s:=s+'s';
                end;
             end;
         end;
        GetString:=s+']';
      end;


    procedure taicpu.ResetPass1;
      begin
        { we need to reset everything here, because the choosen insentry
          can be invalid for a new situation where the previously optimized
          insentry is not correct }
        InsEntry:=nil;
        InsSize:=0;
        LastInsOffset:=-1;
      end;


    procedure taicpu.ResetPass2;
      begin
        { we are here in a second pass, check if the instruction can be optimized }
        if assigned(InsEntry) and
           ((InsEntry^.flags and IF_PASS2)<>0) then
         begin
           InsEntry:=nil;
           InsSize:=0;
         end;
        LastInsOffset:=-1;
      end;


    function taicpu.CheckIfValid:boolean;
      begin
        Result:=False; { unimplemented }
      end;


    function taicpu.Pass1(objdata:TObjData):longint;
      begin
        Pass1:=0;
        LastInsOffset:=-1;
      end;


    procedure taicpu.Pass2(objdata:TObjData);
      begin
        { error in pass1 ? }
        if insentry=nil then
         exit;
        current_filepos:=fileinfo;
        { Generate the instruction }
        GenCode(objdata);
      end;


    procedure taicpu.ppuloadoper(ppufile:tcompilerppufile;var o:toper);
      begin
      end;


    procedure taicpu.ppuwriteoper(ppufile:tcompilerppufile;const o:toper);
      begin
      end;


    procedure taicpu.ppubuildderefimploper(var o:toper);
      begin
      end;


    procedure taicpu.ppuderefoper(var o:toper);
      begin
      end;


    function  taicpu.InsEnd:longint;
      begin
        Result:=0; { unimplemented }
      end;


    procedure taicpu.create_ot(objdata:TObjData);
      begin
      end;


    function taicpu.Matches(p:PInsEntry):longint;
      begin
        result:=0; { unimplemented }
      end;


    function  taicpu.calcsize(p:PInsEntry):shortint;
      begin
        result:=4;
      end;


    function  taicpu.NeedAddrPrefix(opidx:byte):boolean;
      begin
        Result:=False; { unimplemented }
      end;


    procedure taicpu.Swapoperands;
      begin
      end;


    function taicpu.FindInsentry(objdata:TObjData):boolean;
      begin
        result:=false;
      end;


    procedure taicpu.gencode(objdata:TObjData);
      var
        bytes : dword;
        i_field : byte;

      procedure setshifterop(op : byte);
        begin
          case oper[op]^.typ of
            top_const:
              begin
                i_field:=1;
                bytes:=bytes or dword(oper[op]^.val and $fff);
              end;
            top_reg:
              begin
                i_field:=0;
                bytes:=bytes or (getsupreg(oper[op]^.reg) shl 16);

                { does a real shifter op follow? }
                if (op+1<=op) and (oper[op+1]^.typ=top_shifterop) then
                  begin
                  end;
              end;
          else
            internalerror(2005091103);
          end;
        end;

      begin
        bytes:=$0;
        { evaluate and set condition code }

        { condition code allowed? }

        { setup rest of the instruction }
        case insentry^.code[0] of
          #$08:
            begin
              { set instruction code }
              bytes:=bytes or (ord(insentry^.code[1]) shl 26);
              bytes:=bytes or (ord(insentry^.code[2]) shl 21);

              { set destination }
              bytes:=bytes or (getsupreg(oper[0]^.reg) shl 12);

              { create shifter op }
              setshifterop(1);

              { set i field }
              bytes:=bytes or (i_field shl 25);

              { set s if necessary }
              if oppostfix=PF_S then
                bytes:=bytes or (1 shl 20);
            end;
          #$ff:
            internalerror(2005091101);
          else
            internalerror(2005091102);
        end;
        { we're finished, write code }
        objdata.writebytes(bytes,sizeof(bytes));
      end;


{$ifdef dummy}
(*
static void gencode (long segment, long offset, int bits,
                     insn *ins, char *codes, long insn_end)
{
    int has_S_code;             /* S - setflag */
    int has_B_code;             /* B - setflag */
    int has_T_code;             /* T - setflag */
    int has_W_code;             /* ! => W flag */
    int has_F_code;             /* ^ => S flag */
    int keep;
    unsigned char c;
    unsigned char bytes[4];
    long          data, size;
    static int cc_code[] =      /* bit pattern of cc */
  {                             /* order as enum in  */
    0x0E, 0x03, 0x02, 0x00,     /* nasm.h            */
    0x0A, 0x0C, 0x08, 0x0D,
    0x09, 0x0B, 0x04, 0x01,
    0x05, 0x07, 0x06,
  };


#ifdef DEBUG
static char *CC[] =
  {                                    /* condition code names */
    "AL", "CC", "CS", "EQ",
    "GE", "GT", "HI", "LE",
    "LS", "LT", "MI", "NE",
    "PL", "VC", "VS", "",
    "S"
};


    has_S_code = (ins->condition & C_SSETFLAG);
    has_B_code = (ins->condition & C_BSETFLAG);
    has_T_code = (ins->condition & C_TSETFLAG);
    has_W_code = (ins->condition & C_EXSETFLAG);
    has_F_code = (ins->condition & C_FSETFLAG);
    ins->condition = (ins->condition & 0x0F);


    if (rt_debug)
      {
    printf ("gencode: instruction: %s%s", insn_names[ins->opcode],
            CC[ins->condition & 0x0F]);
    if (has_S_code)
      printf ("S");
    if (has_B_code)
      printf ("B");
    if (has_T_code)
      printf ("T");
    if (has_W_code)
      printf ("!");
    if (has_F_code)
      printf ("^");

    printf ("\n");

    c = *codes;

    printf ("   (%d)  decode - '0x%02X'\n", ins->operands, c);


    bytes[0] = 0xB;
    bytes[1] = 0xE;
    bytes[2] = 0xE;
    bytes[3] = 0xF;
      }

    // First condition code in upper nibble
    if (ins->condition < C_NONE)
      {
        c = cc_code[ins->condition] << 4;
      }
    else
      {
        c = cc_code[C_AL] << 4; // is often ALWAYS but not always
      }


    switch (keep = *codes)
      {
        case 1:
          // B, BL
          ++codes;
          c |= *codes++;
          bytes[0] = c;

          if (ins->oprs[0].segment != segment)
            {
              // fais une relocation
              c = 1;
              data = 0; // Let the linker locate ??
            }
          else
            {
              c = 0;
              data = ins->oprs[0].offset - (offset + 8);

              if (data % 4)
                {
                  errfunc (ERR_NONFATAL, "offset not aligned on 4 bytes");
                }
            }

          if (data >= 0x1000)
            {
              errfunc (ERR_NONFATAL, "too long offset");
            }

          data = data >> 2;
          bytes[1] = (data >> 16) & 0xFF;
          bytes[2] = (data >> 8)  & 0xFF;
          bytes[3] = (data )      & 0xFF;

          if (c == 1)
            {
//            out (offset, segment, &bytes[0], OUT_RAWDATA+1, NO_SEG, NO_SEG);
              out (offset, segment, &bytes[0], OUT_REL3ADR+4, ins->oprs[0].segment, NO_SEG);
            }
          else
            {
              out (offset, segment, &bytes[0], OUT_RAWDATA+4, NO_SEG, NO_SEG);
            }
          return;

        case 2:
          // SWI
          ++codes;
          c |= *codes++;
          bytes[0] = c;
          data = ins->oprs[0].offset;
          bytes[1] = (data >> 16) & 0xFF;
          bytes[2] = (data >> 8) & 0xFF;
          bytes[3] = (data) & 0xFF;
          out (offset, segment, &bytes, OUT_RAWDATA+4, NO_SEG, NO_SEG);
          return;
        case 3:
          // BX
          ++codes;
          c |= *codes++;
          bytes[0] = c;
          bytes[1] = *codes++;
          bytes[2] = *codes++;
          bytes[3] = *codes++;
          c = regval (&ins->oprs[0],1);
          if (c == 15)  // PC
            {
              errfunc (ERR_WARNING, "'BX' with R15 has undefined behaviour");
            }
          else if (c > 15)
            {
              errfunc (ERR_NONFATAL, "Illegal register specified for 'BX'");
            }

          bytes[3] |= (c & 0x0F);
          out (offset, segment, bytes, OUT_RAWDATA+4, NO_SEG, NO_SEG);
          return;

        case 4:         // AND Rd,Rn,Rm
        case 5:         // AND Rd,Rn,Rm,<shift>Rs
        case 6:         // AND Rd,Rn,Rm,<shift>imm
        case 7:         // AND Rd,Rn,<shift>imm
          ++codes;
#ifdef DEBUG
          if (rt_debug)
            {
              printf ("         decode - '0x%02X'\n", keep);
              printf ("           code - '0x%02X'\n", (unsigned char) ( *codes));
            }
#endif
          bytes[0] = c | *codes;
          ++codes;

          bytes[1] = *codes;
          if (has_S_code)
            bytes[1] |= 0x10;
          c = regval (&ins->oprs[1],1);
          // Rn in low nibble
          bytes[1] |= c;

          // Rd in high nibble
          bytes[2] = regval (&ins->oprs[0],1) << 4;

          if (keep != 7)
            {
              // Rm in low nibble
              bytes[3] = regval (&ins->oprs[2],1);
            }

          // Shifts if any
          if (keep == 5 || keep == 6)
            {
              // Shift in bytes 2 and 3
              if (keep == 5)
                {
                  // Rs
                  c = regval (&ins->oprs[3],1);
                  bytes[2] |= c;

                  c = 0x10;             // Set bit 4 in byte[3]
                }
              if (keep == 6)
                {
                  c = (ins->oprs[3].offset) & 0x1F;

                  // #imm
                  bytes[2] |= c >> 1;
                  if (c & 0x01)
                    {
                      bytes[3] |= 0x80;
                    }
                  c = 0;                // Clr bit 4 in byte[3]
                }
              // <shift>
              c |= shiftval (&ins->oprs[3]) << 5;

              bytes[3] |= c;
            }

          // reg,reg,imm
          if (keep == 7)
            {
              int shimm;

              shimm = imm_shift (ins->oprs[2].offset);

              if (shimm == -1)
                {
                  errfunc (ERR_NONFATAL, "cannot create that constant");
                }
              bytes[3] = shimm & 0xFF;
              bytes[2] |= (shimm & 0xF00) >> 8;
            }

          out (offset, segment, bytes, OUT_RAWDATA+4, NO_SEG, NO_SEG);
          return;

        case 8:         // MOV Rd,Rm
        case 9:         // MOV Rd,Rm,<shift>Rs
        case 0xA:       // MOV Rd,Rm,<shift>imm
        case 0xB:       // MOV Rd,<shift>imm
          ++codes;
#ifdef DEBUG
          if (rt_debug)
            {
              printf ("         decode - '0x%02X'\n", keep);
              printf ("           code - '0x%02X'\n", (unsigned char) ( *codes));
            }
#endif
          bytes[0] = c | *codes;
          ++codes;

          bytes[1] = *codes;
          if (has_S_code)
            bytes[1] |= 0x10;

          // Rd in high nibble
          bytes[2] = regval (&ins->oprs[0],1) << 4;

          if (keep != 0x0B)
            {
              // Rm in low nibble
              bytes[3] = regval (&ins->oprs[1],1);
            }

          // Shifts if any
          if (keep == 0x09 || keep == 0x0A)
            {
              // Shift in bytes 2 and 3
              if (keep == 0x09)
                {
                  // Rs
                  c = regval (&ins->oprs[2],1);
                  bytes[2] |= c;

                  c = 0x10;             // Set bit 4 in byte[3]
                }
              if (keep == 0x0A)
                {
                  c = (ins->oprs[2].offset) & 0x1F;

                  // #imm
                  bytes[2] |= c >> 1;
                  if (c & 0x01)
                    {
                      bytes[3] |= 0x80;
                    }
                  c = 0;                // Clr bit 4 in byte[3]
                }
              // <shift>
              c |= shiftval (&ins->oprs[2]) << 5;

              bytes[3] |= c;
            }

          // reg,imm
          if (keep == 0x0B)
            {
              int shimm;

              shimm = imm_shift (ins->oprs[1].offset);

              if (shimm == -1)
                {
                  errfunc (ERR_NONFATAL, "cannot create that constant");
                }
              bytes[3] = shimm & 0xFF;
              bytes[2] |= (shimm & 0xF00) >> 8;
            }

          out (offset, segment, bytes, OUT_RAWDATA+4, NO_SEG, NO_SEG);
          return;


        case 0xC:       // CMP Rn,Rm
        case 0xD:       // CMP Rn,Rm,<shift>Rs
        case 0xE:       // CMP Rn,Rm,<shift>imm
        case 0xF:       // CMP Rn,<shift>imm
          ++codes;

          bytes[0] = c | *codes++;

          bytes[1] = *codes;

          // Implicit S code
          bytes[1] |= 0x10;

          c = regval (&ins->oprs[0],1);
          // Rn in low nibble
          bytes[1] |= c;

          // No destination
          bytes[2] = 0;

          if (keep != 0x0B)
            {
              // Rm in low nibble
              bytes[3] = regval (&ins->oprs[1],1);
            }

          // Shifts if any
          if (keep == 0x0D || keep == 0x0E)
            {
              // Shift in bytes 2 and 3
              if (keep == 0x0D)
                {
                  // Rs
                  c = regval (&ins->oprs[2],1);
                  bytes[2] |= c;

                  c = 0x10;             // Set bit 4 in byte[3]
                }
              if (keep == 0x0E)
                {
                  c = (ins->oprs[2].offset) & 0x1F;

                  // #imm
                  bytes[2] |= c >> 1;
                  if (c & 0x01)
                    {
                      bytes[3] |= 0x80;
                    }
                  c = 0;                // Clr bit 4 in byte[3]
                }
              // <shift>
              c |= shiftval (&ins->oprs[2]) << 5;

              bytes[3] |= c;
            }

          // reg,imm
          if (keep == 0x0F)
            {
              int shimm;

              shimm = imm_shift (ins->oprs[1].offset);

              if (shimm == -1)
                {
                  errfunc (ERR_NONFATAL, "cannot create that constant");
                }
              bytes[3] = shimm & 0xFF;
              bytes[2] |= (shimm & 0xF00) >> 8;
            }

          out (offset, segment, bytes, OUT_RAWDATA+4, NO_SEG, NO_SEG);
          return;

        case 0x10:      // MRS Rd,<psr>
          ++codes;

          bytes[0] = c | *codes++;

          bytes[1] = *codes++;

          // Rd
          c = regval (&ins->oprs[0],1);

          bytes[2] = c << 4;

          bytes[3] = 0;

          c = ins->oprs[1].basereg;

          if (c == R_CPSR || c == R_SPSR)
            {
              if (c == R_SPSR)
                {
                  bytes[1] |= 0x40;
                }
            }
          else
            {
              errfunc (ERR_NONFATAL, "CPSR or SPSR expected");
            }

          out (offset, segment, bytes, OUT_RAWDATA+4, NO_SEG, NO_SEG);

          return;

        case 0x11:      // MSR <psr>,Rm
        case 0x12:      // MSR <psrf>,Rm
        case 0x13:      // MSR <psrf>,#expression
          ++codes;

          bytes[0] = c | *codes++;

          bytes[1] = *codes++;

          bytes[2] = *codes;


          if (keep == 0x11 || keep == 0x12)
            {
              // Rm
              c = regval (&ins->oprs[1],1);

              bytes[3] = c;
            }
          else
            {
              int shimm;

              shimm = imm_shift (ins->oprs[1].offset);

              if (shimm == -1)
                {
                  errfunc (ERR_NONFATAL, "cannot create that constant");
                }
              bytes[3] = shimm & 0xFF;
              bytes[2] |= (shimm & 0xF00) >> 8;
            }

          c = ins->oprs[0].basereg;

          if ( keep == 0x11)
            {
              if ( c == R_CPSR || c == R_SPSR)
                {
                if ( c== R_SPSR)
                  {
                    bytes[1] |= 0x40;
                  }
                }
            else
              {
                errfunc (ERR_NONFATAL, "CPSR or SPSR expected");
              }
            }
          else
            {
              if ( c == R_CPSR_FLG || c == R_SPSR_FLG)
                {
                  if ( c== R_SPSR_FLG)
                    {
                      bytes[1] |= 0x40;
                    }
                }
              else
                {
                  errfunc (ERR_NONFATAL, "CPSR_flg or SPSR_flg expected");
                }
            }
          break;

        case 0x14:      // MUL  Rd,Rm,Rs
        case 0x15:      // MULA Rd,Rm,Rs,Rn
          ++codes;

          bytes[0] = c | *codes++;

          bytes[1] = *codes++;

          bytes[3] = *codes;

          // Rd
          bytes[1] |= regval (&ins->oprs[0],1);
          if (has_S_code)
            bytes[1] |= 0x10;

          // Rm
          bytes[3] |= regval (&ins->oprs[1],1);

          // Rs
          bytes[2] = regval (&ins->oprs[2],1);

          if (keep == 0x15)
            {
              bytes[2] |= regval (&ins->oprs[3],1) << 4;
            }
          break;

        case 0x16:      // SMLAL RdHi,RdLo,Rm,Rs
          ++codes;

          bytes[0] = c | *codes++;

          bytes[1] = *codes++;

          bytes[3] = *codes;

          // RdHi
          bytes[1] |= regval (&ins->oprs[1],1);
          if (has_S_code)
            bytes[1] |= 0x10;

          // RdLo
          bytes[2] = regval (&ins->oprs[0],1) << 4;
          // Rm
          bytes[3] |= regval (&ins->oprs[2],1);

          // Rs
          bytes[2] |= regval (&ins->oprs[3],1);

          break;

        case 0x17:      // LDR Rd, expression
          ++codes;

          bytes[0] = c | *codes++;

          bytes[1] = *codes++;

          // Rd
          bytes[2] = regval (&ins->oprs[0],1) << 4;
          if (has_B_code)
            bytes[1] |= 0x40;
          if (has_T_code)
            {
              errfunc (ERR_NONFATAL, "'T' not allowed in pre-index mode");
            }
          if (has_W_code)
            {
              errfunc (ERR_NONFATAL, "'!' not allowed");
            }

          // Rn - implicit R15
          bytes[1] |= 0xF;

          if (ins->oprs[1].segment != segment)
            {
              errfunc (ERR_NONFATAL, "label not in same segment");
            }

          data = ins->oprs[1].offset - (offset + 8);

          if (data < 0)
            {
              data = -data;
            }
          else
            {
              bytes[1] |= 0x80;
            }

          if (data >= 0x1000)
            {
              errfunc (ERR_NONFATAL, "too long offset");
            }

          bytes[2] |= ((data & 0xF00) >> 8);
          bytes[3] = data & 0xFF;
          break;

        case 0x18:      // LDR Rd, [Rn]
          ++codes;

          bytes[0] = c | *codes++;

          bytes[1] = *codes++;

          // Rd
          bytes[2] = regval (&ins->oprs[0],1) << 4;
          if (has_B_code)
            bytes[1] |= 0x40;
          if (has_T_code)
            {
              bytes[1] |= 0x20;         // write-back
            }
          else
            {
              bytes[0] |= 0x01;         // implicit pre-index mode
            }

          if (has_W_code)
            {
              bytes[1] |= 0x20;         // write-back
            }

          // Rn
          c = regval (&ins->oprs[1],1);
          bytes[1] |= c;

          if (c == 0x15)                // R15
            data = -8;
          else
            data = 0;

          if (data < 0)
            {
              data = -data;
            }
          else
            {
              bytes[1] |= 0x80;
            }

          bytes[2] |= ((data & 0xF00) >> 8);
          bytes[3] = data & 0xFF;
          break;

        case 0x19:      // LDR Rd, [Rn,#expression]
        case 0x20:      // LDR Rd, [Rn,Rm]
        case 0x21:      // LDR Rd, [Rn,Rm,shift]
          ++codes;

          bytes[0] = c | *codes++;

          bytes[1] = *codes++;

          // Rd
          bytes[2] = regval (&ins->oprs[0],1) << 4;
          if (has_B_code)
            bytes[1] |= 0x40;

          // Rn
          c = regval (&ins->oprs[1],1);
          bytes[1] |= c;

          if (ins->oprs[ins->operands-1].bracket)       // FIXME: Bracket on last operand -> pre-index  <--
            {
              bytes[0] |= 0x01;         // pre-index mode
              if (has_W_code)
                {
                  bytes[1] |= 0x20;
                }
              if (has_T_code)
                {
                  errfunc (ERR_NONFATAL, "'T' not allowed in pre-index mode");
                }
            }
          else
            {
              if (has_T_code)           // Forced write-back in post-index mode
                {
                  bytes[1] |= 0x20;
                }
              if (has_W_code)
                {
                  errfunc (ERR_NONFATAL, "'!' not allowed in post-index mode");
                }
            }

          if (keep == 0x19)
            {
              data = ins->oprs[2].offset;

              if (data < 0)
                {
                  data = -data;
                }
              else
                {
                  bytes[1] |= 0x80;
                }

              if (data >= 0x1000)
                {
                  errfunc (ERR_NONFATAL, "too long offset");
                }

              bytes[2] |= ((data & 0xF00) >> 8);
              bytes[3] = data & 0xFF;
            }
          else
            {
              if (ins->oprs[2].minus == 0)
                {
                  bytes[1] |= 0x80;
                }
              c = regval (&ins->oprs[2],1);
              bytes[3] = c;

              if (keep == 0x21)
                {
                  c = ins->oprs[3].offset;
                  if (c > 0x1F)
                    {
                      errfunc (ERR_NONFATAL, "too large shiftvalue");
                      c = c & 0x1F;
                    }

                  bytes[2] |= c >> 1;
                  if (c & 0x01)
                    {
                      bytes[3] |= 0x80;
                    }
                  bytes[3] |= shiftval (&ins->oprs[3]) << 5;
                }
            }

          break;

        case 0x22:      // LDRH Rd, expression
          ++codes;

          bytes[0] = c | 0x01;          // Implicit pre-index

          bytes[1] = *codes++;

          // Rd
          bytes[2] = regval (&ins->oprs[0],1) << 4;

          // Rn - implicit R15
          bytes[1] |= 0xF;

          if (ins->oprs[1].segment != segment)
            {
              errfunc (ERR_NONFATAL, "label not in same segment");
            }

          data = ins->oprs[1].offset - (offset + 8);

          if (data < 0)
            {
              data = -data;
            }
          else
            {
              bytes[1] |= 0x80;
            }

          if (data >= 0x100)
            {
              errfunc (ERR_NONFATAL, "too long offset");
            }
          bytes[3] = *codes++;

          bytes[2] |= ((data & 0xF0) >> 4);
          bytes[3] |= data & 0xF;
          break;

        case 0x23:      // LDRH Rd, Rn
          ++codes;

          bytes[0] = c | 0x01;          // Implicit pre-index

          bytes[1] = *codes++;

          // Rd
          bytes[2] = regval (&ins->oprs[0],1) << 4;

          // Rn
          c = regval (&ins->oprs[1],1);
          bytes[1] |= c;

          if (c == 0x15)                // R15
            data = -8;
          else
            data = 0;

          if (data < 0)
            {
              data = -data;
            }
          else
            {
              bytes[1] |= 0x80;
            }

          if (data >= 0x100)
            {
              errfunc (ERR_NONFATAL, "too long offset");
            }
          bytes[3] = *codes++;

          bytes[2] |= ((data & 0xF0) >> 4);
          bytes[3] |= data & 0xF;
          break;

        case 0x24:      // LDRH Rd, Rn, expression
        case 0x25:      // LDRH Rd, Rn, Rm
          ++codes;

          bytes[0] = c;

          bytes[1] = *codes++;

          // Rd
          bytes[2] = regval (&ins->oprs[0],1) << 4;

          // Rn
          c = regval (&ins->oprs[1],1);
          bytes[1] |= c;

          if (ins->oprs[ins->operands-1].bracket)       // FIXME: Bracket on last operand -> pre-index  <--
            {
              bytes[0] |= 0x01;         // pre-index mode
              if (has_W_code)
                {
                  bytes[1] |= 0x20;
                }
            }
          else
            {
              if (has_W_code)
                {
                  errfunc (ERR_NONFATAL, "'!' not allowed in post-index mode");
                }
            }

          bytes[3] = *codes++;

          if (keep == 0x24)
            {
              data = ins->oprs[2].offset;

              if (data < 0)
                {
                  data = -data;
                }
              else
                {
                  bytes[1] |= 0x80;
                }

              if (data >= 0x100)
                {
                  errfunc (ERR_NONFATAL, "too long offset");
                }

              bytes[2] |= ((data & 0xF0) >> 4);
              bytes[3] |= data & 0xF;
            }
          else
            {
              if (ins->oprs[2].minus == 0)
                {
                  bytes[1] |= 0x80;
                }
              c = regval (&ins->oprs[2],1);
              bytes[3] |= c;

            }
          break;

        case 0x26:      // LDM/STM Rn, {reg-list}
          ++codes;

          bytes[0] = c;

          bytes[0] |= ( *codes >> 4) & 0xF;
          bytes[1] = ( *codes << 4) & 0xF0;
          ++codes;

          if (has_W_code)
            {
              bytes[1] |= 0x20;
            }
          if (has_F_code)
            {
              bytes[1] |= 0x40;
            }

          // Rn
          bytes[1] |= regval (&ins->oprs[0],1);

          data = ins->oprs[1].basereg;

          bytes[2] = ((data >> 8) & 0xFF);
          bytes[3] = (data & 0xFF);

          break;

        case 0x27:      // SWP Rd, Rm, [Rn]
          ++codes;

          bytes[0] = c;

          bytes[0] |= *codes++;

          bytes[1] = regval (&ins->oprs[2],1);
          if (has_B_code)
            {
              bytes[1] |= 0x40;
            }
          bytes[2] = regval (&ins->oprs[0],1) << 4;
          bytes[3] = *codes++;
          bytes[3] |= regval (&ins->oprs[1],1);
          break;

        default:
          errfunc (ERR_FATAL, "unknown decoding of instruction");

          bytes[0] = c;
          // And a fix nibble
          ++codes;
          bytes[0] |= *codes++;

         if ( *codes == 0x01)           // An I bit
           {

           }
         if ( *codes == 0x02)           // An I bit
           {

           }
         ++codes;
      }
    out (offset, segment, bytes, OUT_RAWDATA+4, NO_SEG, NO_SEG);
}

*)
{$endif dummy}

begin
  cai_align:=tai_align;
end.