fpc/compiler/powerpc/cgcpu.pas

{
    $Id$
    Copyright (c) 1998-2002 by Florian Klaempfl

    This unit implements the code generator for the PowerPC

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

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

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

 ****************************************************************************
}
unit cgcpu;

{$i fpcdefs.inc}

  interface

    uses
       cgbase,cgobj,
       aasmbase,aasmcpu,aasmtai,
       cpubase,cpuinfo,node,cg64f32,cginfo;

    type
      tcgppc = class(tcg)
        { passing parameters, per default the parameter is pushed }
        { nr gives the number of the parameter (enumerated from   }
        { left to right), this allows to move the parameter to    }
        { register, if the cpu supports register calling          }
        { conventions                                             }
        procedure a_param_const(list : taasmoutput;size : tcgsize;a : aword;const locpara : tparalocation);override;
        procedure a_param_ref(list : taasmoutput;size : tcgsize;const r : treference;const locpara : tparalocation);override;
        procedure a_paramaddr_ref(list : taasmoutput;const r : treference;const locpara : tparalocation);override;


        procedure a_call_name(list : taasmoutput;const s : string);override;
        procedure a_call_ref(list : taasmoutput;const ref : treference);override;

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

        procedure a_op_const_reg_reg(list: taasmoutput; op: TOpCg;
          size: tcgsize; a: aword; src, dst: tregister); override;
        procedure a_op_reg_reg_reg(list: taasmoutput; op: TOpCg;
          size: tcgsize; src1, src2, dst: tregister); override;

        { move instructions }
        procedure a_load_const_reg(list : taasmoutput; size: tcgsize; a : aword;reg : tregister);override;
        procedure a_load_reg_ref(list : taasmoutput; size: tcgsize; reg : tregister;const ref : treference);override;
        procedure a_load_ref_reg(list : taasmoutput;size : tcgsize;const Ref : treference;reg : tregister);override;
        procedure a_load_reg_reg(list : taasmoutput;size : tcgsize;reg1,reg2 : tregister);override;
        procedure a_load_sym_ofs_reg(list: taasmoutput; const sym: tasmsymbol; ofs: longint; reg: tregister); override;

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

        {  comparison operations }
        procedure a_cmp_const_reg_label(list : taasmoutput;size : tcgsize;cmp_op : topcmp;a : aword;reg : tregister;
          l : tasmlabel);override;
        procedure a_cmp_reg_reg_label(list : taasmoutput;size : tcgsize;cmp_op : topcmp;reg1,reg2 : tregister;l : tasmlabel); override;

        procedure a_jmp_always(list : taasmoutput;l: tasmlabel); override;
        procedure a_jmp_flags(list : taasmoutput;const f : TResFlags;l: tasmlabel); override;

        procedure g_flags2reg(list: taasmoutput; size: TCgSize; const f: TResFlags; reg: TRegister); override;


        procedure g_stackframe_entry_sysv(list : taasmoutput;localsize : longint);
        procedure g_stackframe_entry_mac(list : taasmoutput;localsize : longint);
        procedure g_stackframe_entry(list : taasmoutput;localsize : longint);override;
        procedure g_restore_frame_pointer(list : taasmoutput);override;
        procedure g_return_from_proc(list : taasmoutput;parasize : aword); override;

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

        procedure g_concatcopy(list : taasmoutput;const source,dest : treference;len : aword; delsource,loadref : boolean);override;

        procedure g_overflowcheck(list: taasmoutput; const p: tnode); override;
        { find out whether a is of the form 11..00..11b or 00..11...00. If }
        { that's the case, we can use rlwinm to do an AND operation        }
        function get_rlwi_const(a: longint; var l1, l2: longint): boolean;

        procedure g_push_exception(list : taasmoutput;const exceptbuf:treference;l:AWord; exceptlabel:TAsmLabel);override;
        procedure g_pop_exception(list : taasmoutput;endexceptlabel:tasmlabel);override;

        procedure g_save_standard_registers(list : taasmoutput);override;
        procedure g_restore_standard_registers(list : taasmoutput);override;
        procedure g_save_all_registers(list : taasmoutput);override;
        procedure g_restore_all_registers(list : taasmoutput;selfused,accused,acchiused:boolean);override;
        private

        procedure a_jmp_cond(list : taasmoutput;cond : TOpCmp;l: tasmlabel);

        procedure g_return_from_proc_sysv(list : taasmoutput;parasize : aword);
        procedure g_return_from_proc_mac(list : taasmoutput;parasize : aword);


        { Make sure ref is a valid reference for the PowerPC and sets the }
        { base to the value of the index if (base = R_NO).                }
        procedure fixref(list: taasmoutput; var ref: treference);

        { contains the common code of a_load_reg_ref and a_load_ref_reg }
        procedure a_load_store(list:taasmoutput;op: tasmop;reg:tregister;
                    ref: treference);

        { creates the correct branch instruction for a given combination }
        { of asmcondflags and destination addressing mode                }
        procedure a_jmp(list: taasmoutput; op: tasmop;
                        c: tasmcondflag; crval: longint; l: tasmlabel);

     end;

     tcg64fppc = class(tcg64f32)
       procedure a_op64_reg_reg(list : taasmoutput;op:TOpCG;regsrc,regdst : tregister64);override;
       procedure a_op64_const_reg(list : taasmoutput;op:TOpCG;value : qword;reg : tregister64);override;
       procedure a_op64_const_reg_reg(list: taasmoutput;op:TOpCG;value : qword;regsrc,regdst : tregister64);override;
       procedure a_op64_reg_reg_reg(list: taasmoutput;op:TOpCG;regsrc1,regsrc2,regdst : tregister64);override;
     end;


const
  TOpCG2AsmOpConstLo: Array[topcg] of TAsmOp = (A_NONE,A_ADDI,A_ANDI_,A_DIVWU,
                        A_DIVW,A_MULLW, A_MULLW, A_NONE,A_NONE,A_ORI,
                        A_SRAWI,A_SLWI,A_SRWI,A_SUBI,A_XORI);
  TOpCG2AsmOpConstHi: Array[topcg] of TAsmOp = (A_NONE,A_ADDIS,A_ANDIS_,
                        A_DIVWU,A_DIVW, A_MULLW,A_MULLW,A_NONE,A_NONE,
                        A_ORIS,A_NONE, A_NONE,A_NONE,A_SUBIS,A_XORIS);

  TOpCmp2AsmCond: Array[topcmp] of TAsmCondFlag = (C_NONE,C_EQ,C_GT,
                       C_LT,C_GE,C_LE,C_NE,C_LE,C_NG,C_GE,C_NL);

  implementation

    uses
       globtype,globals,verbose,systems,cutils,symconst,symdef,rgobj;

{ parameter passing... Still needs extra support from the processor }
{ independent code generator                                        }

    procedure tcgppc.a_param_const(list : taasmoutput;size : tcgsize;a : aword;const locpara : tparalocation);

      var
        ref: treference;

      begin
        case locpara.loc of
          LOC_REGISTER:
            a_load_const_reg(list,size,a,locpara.register);
          LOC_REFERENCE:
            begin
               reference_reset(ref);
               ref.base:=locpara.reference.index;
               ref.offset:=locpara.reference.offset;
               a_load_const_ref(list,size,a,ref);
            end;
          else
            internalerror(2002081101);
        end;
        if locpara.sp_fixup<>0 then
          internalerror(2002081102);
      end;


    procedure tcgppc.a_param_ref(list : taasmoutput;size : tcgsize;const r : treference;const locpara : tparalocation);

      var
        ref: treference;
        tmpreg: tregister;

      begin
        case locpara.loc of
          LOC_REGISTER:
            a_load_ref_reg(list,size,r,locpara.register);
          LOC_REFERENCE:
            begin
               reference_reset(ref);
               ref.base:=locpara.reference.index;
               ref.offset:=locpara.reference.offset;
               tmpreg := get_scratch_reg_int(list);
               a_load_ref_reg(list,size,r,tmpreg);
               a_load_reg_ref(list,size,tmpreg,ref);
               free_scratch_reg(list,tmpreg);
            end;
          LOC_FPUREGISTER:
            case size of
               OS_32:
                 a_loadfpu_ref_reg(list,OS_F32,r,locpara.register);
               OS_64:
                 a_loadfpu_ref_reg(list,OS_F64,r,locpara.register);
               else
                 internalerror(2002072801);
            end;
          else
            internalerror(2002081103);
        end;
        if locpara.sp_fixup<>0 then
          internalerror(2002081104);
      end;


    procedure tcgppc.a_paramaddr_ref(list : taasmoutput;const r : treference;const locpara : tparalocation);

      var
        ref: treference;
        tmpreg: tregister;

      begin
  {$ifdef para_sizes_known}
        if (nr <= max_param_regs_int) then
          a_loadaddr_ref_reg(list,size,r,param_regs_int[nr])
        else
          begin
            reset_reference(ref);
            ref.base := STACK_POINTER_REG;
            ref.offset := LinkageAreaSize+para_size_till_now;
            tmpreg := get_scratch_reg_address(list);
            a_loadaddr_ref_reg(list,size,r,tmpreg);
            a_load_reg_ref(list,size,tmpreg,ref);
            free_scratch_reg(list,tmpreg);
          end;
  {$endif para_sizes_known}
      end;

    { calling a code fragment by name }
    procedure tcgppc.a_call_name(list : taasmoutput;const s : string);

      var
        href : treference;
      begin
         { save our RTOC register value. Only necessary when doing pointer based    }
         { calls or cross TOC calls, but currently done always                      }
         reference_reset_base(href,STACK_POINTER_REG,LA_RTOC);
         list.concat(taicpu.op_reg_ref(A_STW,R_TOC,href));
         list.concat(taicpu.op_sym(A_BL,newasmsymbol(s)));
         reference_reset_base(href,STACK_POINTER_REG,LA_RTOC);
         list.concat(taicpu.op_reg_ref(A_LWZ,R_TOC,href));
      end;

    { calling a code fragment through a reference }
    procedure tcgppc.a_call_ref(list : taasmoutput;const ref : treference);
      begin
         {$warning FIX ME}
      end;

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

     procedure tcgppc.a_load_const_reg(list : taasmoutput; size: TCGSize; a : aword; reg : TRegister);

       begin
          if (longint(a) >= low(smallint)) and
             (longint(a) <= high(smallint)) then
            list.concat(taicpu.op_reg_const(A_LI,reg,smallint(a)))
          else if ((a and $ffff) <> 0) then
            begin
              list.concat(taicpu.op_reg_const(A_LI,reg,smallint(a and $ffff)));
              if ((a shr 16) <> 0) then
                list.concat(taicpu.op_reg_const(A_ADDIS,reg,
                  smallint((a shr 16)+ord(smallint(a and $ffff) < 0))))
            end
          else
            list.concat(taicpu.op_reg_const(A_LIS,reg,smallint(a shr 16)));
       end;


     procedure tcgppc.a_load_reg_ref(list : taasmoutput; size: TCGSize; reg : tregister;const ref : treference);

       const
         StoreInstr: Array[OS_8..OS_32,boolean, boolean] of TAsmOp =
                                 { indexed? updating?}
                    (((A_STB,A_STBU),(A_STBX,A_STBUX)),
                     ((A_STH,A_STHU),(A_STHX,A_STHUX)),
                     ((A_STW,A_STWU),(A_STWX,A_STWUX)));
       var
         op: TAsmOp;
         ref2: TReference;

       begin
         ref2 := ref;
         FixRef(list,ref2);
         if size in [OS_S8..OS_S16] then
           { storing is the same for signed and unsigned values }
           size := tcgsize(ord(size)-(ord(OS_S8)-ord(OS_8)));
         { 64 bit stuff should be handled separately }
         if size in [OS_64,OS_S64] then
           internalerror(200109236);
         op := storeinstr[tcgsize2unsigned[size],ref2.index<>R_NO,false];
         a_load_store(list,op,reg,ref2);
       End;


     procedure tcgppc.a_load_ref_reg(list : taasmoutput;size : tcgsize;const ref: treference;reg : tregister);

       const
         LoadInstr: Array[OS_8..OS_S32,boolean, boolean] of TAsmOp =
                                { indexed? updating?}
                    (((A_LBZ,A_LBZU),(A_LBZX,A_LBZUX)),
                     ((A_LHZ,A_LHZU),(A_LHZX,A_LHZUX)),
                     ((A_LWZ,A_LWZU),(A_LWZX,A_LWZUX)),
                     { 64bit stuff should be handled separately }
                     ((A_NONE,A_NONE),(A_NONE,A_NONE)),
                     { there's no load-byte-with-sign-extend :( }
                     ((A_LBZ,A_LBZU),(A_LBZX,A_LBZUX)),
                     ((A_LHA,A_LHAU),(A_LHAX,A_LHAUX)),
                     ((A_LWZ,A_LWZU),(A_LWZX,A_LWZUX)));
       var
         op: tasmop;
         tmpreg: tregister;
         ref2, tmpref: treference;

       begin
          ref2 := ref;
          fixref(list,ref2);
          op := loadinstr[size,ref2.index<>R_NO,false];
          a_load_store(list,op,reg,ref2);
          { sign extend shortint if necessary, since there is no }
          { load instruction that does that automatically (JM)   }
          if size = OS_S8 then
            list.concat(taicpu.op_reg_reg(A_EXTSB,reg,reg));
       end;


     procedure tcgppc.a_load_reg_reg(list : taasmoutput;size : tcgsize;reg1,reg2 : tregister);

       begin
         if (reg1 <> reg2) or
            not(size in [OS_32,OS_S32]) then
           begin
             case size of
               OS_8:
                 list.concat(taicpu.op_reg_reg_const_const_const(A_RLWINM,
                   reg2,reg1,0,31-8+1,31));
               OS_S8:
                 list.concat(taicpu.op_reg_reg(A_EXTSB,reg2,reg1));
               OS_16:
                 list.concat(taicpu.op_reg_reg_const_const_const(A_RLWINM,
                   reg2,reg1,0,31-16+1,31));
               OS_S16:
                 list.concat(taicpu.op_reg_reg(A_EXTSH,reg2,reg1));
               OS_32,OS_S32:
                 list.concat(taicpu.op_reg_reg(A_MR,reg2,reg1));
             end;
           end;
       end;

     procedure tcgppc.a_load_sym_ofs_reg(list: taasmoutput; const sym: tasmsymbol; ofs: longint; reg: tregister);

       begin
         { can't use op_sym_ofs_reg because sym+ofs can be > 32767!! }
         internalerror(200112293);
       end;


     procedure tcgppc.a_loadfpu_reg_reg(list: taasmoutput; reg1, reg2: tregister);

       begin
         list.concat(taicpu.op_reg_reg(A_FMR,reg1,reg2));
       end;

     procedure tcgppc.a_loadfpu_ref_reg(list: taasmoutput; size: tcgsize; const ref: treference; reg: tregister);

       const
         FpuLoadInstr: Array[OS_F32..OS_F64,boolean, boolean] of TAsmOp =
                          { indexed? updating?}
                    (((A_LFS,A_LFSU),(A_LFSX,A_LFSUX)),
                     ((A_LFD,A_LFDU),(A_LFDX,A_LFDUX)));
       var
         op: tasmop;
         ref2: treference;
       begin
          { several functions call this procedure with OS_32 or OS_64 }
          { so this makes life easier (FK)                            }
          case size of
             OS_32,OS_F32:
               size:=OS_F32;
             OS_64,OS_F64:
               size:=OS_F64;
             else
               internalerror(200201121);
          end;
         ref2 := ref;
         fixref(list,ref2);
         op := fpuloadinstr[size,ref2.index <> R_NO,false];
         a_load_store(list,op,reg,ref2);
       end;

     procedure tcgppc.a_loadfpu_reg_ref(list: taasmoutput; size: tcgsize; reg: tregister; const ref: treference);

       const
         FpuStoreInstr: Array[OS_F32..OS_F64,boolean, boolean] of TAsmOp =
                            { indexed? updating?}
                    (((A_STFS,A_STFSU),(A_STFSX,A_STFSUX)),
                     ((A_STFD,A_STFDU),(A_STFDX,A_STFDUX)));
       var
         op: tasmop;
         ref2: treference;
       begin
         if not(size in [OS_F32,OS_F64]) then
           internalerror(200201122);
         ref2 := ref;
         fixref(list,ref2);
         op := fpustoreinstr[size,ref2.index <> R_NO,false];
         a_load_store(list,op,reg,ref2);
       end;


     procedure tcgppc.a_op_const_reg(list : taasmoutput; Op: TOpCG; a: AWord; reg: TRegister);

       var
         scratch_register: TRegister;

       begin
         a_op_const_reg_reg(list,op,OS_32,a,reg,reg);
       end;


      procedure tcgppc.a_op_reg_reg(list : taasmoutput; Op: TOpCG; size: TCGSize; src, dst: TRegister);

         begin
           a_op_reg_reg_reg(list,op,OS_32,src,dst,dst);
         end;


    procedure tcgppc.a_op_const_reg_reg(list: taasmoutput; op: TOpCg;
                       size: tcgsize; a: aword; src, dst: tregister);
      var
        l1,l2: longint;
        oplo, ophi: tasmop;
        scratchreg: tregister;
        useReg, gotrlwi: boolean;


        function try_lo_hi: boolean;
          begin
            result := false;
            if (smallint(a) > 0) then
              begin
                list.concat(taicpu.op_reg_reg_const(oplo,dst,src,smallint(a)));
                list.concat(taicpu.op_reg_reg_const(ophi,dst,dst,smallint(a shr 16)));
                result := true;
              end;
          end;

      begin
        if op = OP_SUB then
          begin
{$ifopt q+}
{$q-}
{$define overflowon}
{$endif}
            a_op_const_reg_reg(list,op,size,aword(-a),src,dst);
{$ifdef overflowon}
{$q+}
{$undef overflowon}
{$endif}
            exit;
          end;
        ophi := TOpCG2AsmOpConstHi[op];
        oplo := TOpCG2AsmOpConstLo[op];
        gotrlwi := get_rlwi_const(a,l1,l2);
        { constants in a PPC instruction are always interpreted as signed }
        { 16bit values, so if the value is between low(smallint) and      }
        { high(smallint), it's easy                                       }
        if (op in [OP_ADD,OP_AND,OP_OR,OP_XOR]) then
          begin
            if (a = 0) then
              begin
                if op = OP_AND then
                  list.concat(taicpu.op_reg_const(A_LI,dst,0));
                exit;
              end
            else if (a = high(aword)) and
                    (op in [OP_AND,OP_OR]) then
              begin
                if op = OP_OR then
                  list.concat(taicpu.op_reg_const(A_LI,dst,-1));
                exit;
              end
            else if (longint(a) >= low(smallint)) and
               (longint(a) <= high(smallint)) and
               ((op <> OP_AND) or
                 not gotrlwi) then
              begin
                list.concat(taicpu.op_reg_reg_const(oplo,dst,src,smallint(a)));
                exit;
              end;
            { all basic constant instructions also have a shifted form that }
            { works only on the highest 16bits, so if lo(a) is 0, we can    }
            { use that one                                                  }
            if (word(a) = 0) and
               (not(op = OP_AND) or
                not gotrlwi) then
              begin
                list.concat(taicpu.op_reg_reg_const(ophi,dst,src,smallint(a shr 16)));
                exit;
              end;
          end;
        { otherwise, the instructions we can generate depend on the }
        { operation                                                 }
        useReg := false;
        case op of
          OP_DIV,OP_IDIV:
            useReg := true;
           OP_IMUL, OP_MUL:
             if (longint(a) >= low(smallint)) and
                (longint(a) <= high(smallint)) then
               list.concat(taicpu.op_reg_reg_const(A_MULLI,dst,src,smallint(a)))
             else
               usereg := true;
          OP_ADD:
            begin
              list.concat(taicpu.op_reg_reg_const(oplo,dst,src,smallint(a)));
              list.concat(taicpu.op_reg_reg_const(ophi,dst,dst,
                smallint((a shr 16) + ord(smallint(a) < 0))));
            end;
          OP_OR:
            { try to use rlwimi }
            if gotrlwi then
              begin
                if src <> dst then
                  list.concat(taicpu.op_reg_reg(A_MR,dst,src));
                scratchreg := get_scratch_reg_int(list);
                list.concat(taicpu.op_reg_const(A_LI,scratchreg,-1));
                list.concat(taicpu.op_reg_reg_const_const_const(A_RLWIMI,dst,
                  scratchreg,0,l1,l2));
                free_scratch_reg(list,scratchreg);
              end
            else if not try_lo_hi then
              useReg := true;
          OP_AND:
            { try to use rlwinm }
            if gotrlwi then
              list.concat(taicpu.op_reg_reg_const_const_const(A_RLWINM,dst,
                src,0,l1,l2))
            else
              useReg := true;
          OP_XOR:
            if not try_lo_hi then
              usereg := true;
          OP_SHL,OP_SHR,OP_SAR:
            begin
              if (a and 31) <> 0 Then
                list.concat(taicpu.op_reg_reg_const(
                  TOpCG2AsmOpConstLo[Op],dst,src,a and 31));
              if (a shr 5) <> 0 then
                internalError(68991);
            end
          else
            internalerror(200109091);
        end;
        { if all else failed, load the constant in a register and then }
        { perform the operation                                        }
        if useReg then
          begin
            scratchreg := get_scratch_reg_int(list);
            a_load_const_reg(list,OS_32,a,scratchreg);
            a_op_reg_reg_reg(list,op,OS_32,scratchreg,src,dst);
            free_scratch_reg(list,scratchreg);
          end;
      end;


    procedure tcgppc.a_op_reg_reg_reg(list: taasmoutput; op: TOpCg;
      size: tcgsize; src1, src2, dst: tregister);

      const
        op_reg_reg_opcg2asmop: array[TOpCG] of tasmop =
          (A_NONE,A_ADD,A_AND,A_DIVWU,A_DIVW,A_MULLW,A_MULLW,A_NEG,A_NOT,A_OR,
           A_SRAW,A_SLW,A_SRW,A_SUB,A_XOR);

       begin
         case op of
           OP_NEG,OP_NOT:
             list.concat(taicpu.op_reg_reg(op_reg_reg_opcg2asmop[op],dst,dst));
           else
             list.concat(taicpu.op_reg_reg_reg(op_reg_reg_opcg2asmop[op],dst,src2,src1));
         end;
       end;


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

      procedure tcgppc.a_cmp_const_reg_label(list : taasmoutput;size : tcgsize;cmp_op : topcmp;a : aword;reg : tregister;
        l : tasmlabel);

        var
          p: taicpu;
          scratch_register: TRegister;
          signed: boolean;

        begin
          signed := cmp_op in [OC_GT,OC_LT,OC_GTE,OC_LTE];
          { in the following case, we generate more efficient code when }
          { signed is true                                              }
          if (cmp_op in [OC_EQ,OC_NE]) and
             (a > $ffff) then
            signed := true;
          if signed then
            if (longint(a) >= low(smallint)) and (longint(a) <= high(smallint)) Then
              list.concat(taicpu.op_reg_reg_const(A_CMPWI,R_CR0,reg,longint(a)))
            else
              begin
                scratch_register := get_scratch_reg_int(list);
                a_load_const_reg(list,OS_32,a,scratch_register);
                list.concat(taicpu.op_reg_reg_reg(A_CMPW,R_CR0,reg,scratch_register));
                free_scratch_reg(list,scratch_register);
              end
          else
            if (a <= $ffff) then
              list.concat(taicpu.op_reg_reg_const(A_CMPLWI,R_CR0,reg,a))
            else
              begin
                scratch_register := get_scratch_reg_int(list);
                a_load_const_reg(list,OS_32,a,scratch_register);
                list.concat(taicpu.op_reg_reg_reg(A_CMPLW,R_CR0,reg,scratch_register));
                free_scratch_reg(list,scratch_register);
              end;
          a_jmp(list,A_BC,TOpCmp2AsmCond[cmp_op],0,l);
        end;


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

        var
          p: taicpu;
            op: tasmop;

        begin
          if cmp_op in [OC_GT,OC_LT,OC_GTE,OC_LTE] then
            op := A_CMPW
          else op := A_CMPLW;
          list.concat(taicpu.op_reg_reg_reg(op,R_CR0,reg1,reg2));
          a_jmp(list,A_BC,TOpCmp2AsmCond[cmp_op],0,l);
        end;


     procedure tcgppc.g_push_exception(list : taasmoutput;const exceptbuf:treference;l:AWord; exceptlabel:TAsmLabel);
       begin
         {$warning FIX ME}
       end;

     procedure tcgppc.g_pop_exception(list : taasmoutput;endexceptlabel:tasmlabel);
       begin
         {$warning FIX ME}
       end;

     procedure tcgppc.g_save_standard_registers(list : taasmoutput);
       begin
         {$warning FIX ME}
       end;

     procedure tcgppc.g_restore_standard_registers(list : taasmoutput);
       begin
         {$warning FIX ME}
       end;

     procedure tcgppc.g_save_all_registers(list : taasmoutput);
       begin
         {$warning FIX ME}
       end;

     procedure tcgppc.g_restore_all_registers(list : taasmoutput;selfused,accused,acchiused:boolean);
       begin
         {$warning FIX ME}
       end;

     procedure tcgppc.a_jmp_cond(list : taasmoutput;cond : TOpCmp;l: tasmlabel);

       begin
         a_jmp(list,A_BC,TOpCmp2AsmCond[cond],0,l);
       end;

     procedure tcgppc.a_jmp_always(list : taasmoutput;l: tasmlabel);

       begin
         a_jmp(list,A_B,C_None,0,l);
       end;

     procedure tcgppc.a_jmp_flags(list : taasmoutput;const f : TResFlags;l: tasmlabel);

       var
         c: tasmcond;
       begin
         c := flags_to_cond(f);
         a_jmp(list,A_BC,c.cond,ord(c.cr)-ord(R_CR0),l);
       end;

     procedure tcgppc.g_flags2reg(list: taasmoutput; size: TCgSize; const f: TResFlags; reg: TRegister);

       var
         testbit: byte;
         bitvalue: boolean;

       begin
         { get the bit to extract from the conditional register + its }
         { requested value (0 or 1)                                   }
         testbit := ((ord(f.cr)-ord(R_CR0)) * 4);
         case f.flag of
           F_EQ,F_NE:
             bitvalue := f.flag = F_EQ;
           F_LT,F_GE:
             begin
               inc(testbit);
               bitvalue := f.flag = F_LT;
             end;
           F_GT,F_LE:
             begin
               inc(testbit,2);
               bitvalue := f.flag = F_GT;
             end;
           else
             internalerror(200112261);
         end;
         { load the conditional register in the destination reg }
         list.concat(taicpu.op_reg(A_MFCR,reg));
         { we will move the bit that has to be tested to bit 0 by rotating }
         { left                                                            }
         testbit := (32 - testbit) and 31;
         { extract bit }
         if testbit <> 0 then
           list.concat(taicpu.op_reg_reg_const_const_const(
             A_RLWINM,reg,reg,testbit,31,31));
         { if we need the inverse, xor with 1 }
         if not bitvalue then
           list.concat(taicpu.op_reg_reg_const(A_XORI,reg,reg,1));
       end;

(*
     procedure tcgppc.g_cond2reg(list: taasmoutput; const f: TAsmCond; reg: TRegister);

       var
         testbit: byte;
         bitvalue: boolean;

       begin
         { get the bit to extract from the conditional register + its }
         { requested value (0 or 1)                                   }
         case f.simple of
           false:
             begin
               { we don't generate this in the compiler }
               internalerror(200109062);
             end;
           true:
             case f.cond of
               C_None:
                 internalerror(200109063);
               C_LT..C_NU:
                 begin
                   testbit := (ord(f.cr) - ord(R_CR0))*4;
                   inc(testbit,AsmCondFlag2BI[f.cond]);
                   bitvalue := AsmCondFlagTF[f.cond];
                 end;
               C_T,C_F,C_DNZT,C_DNZF,C_DZT,C_DZF:
                 begin
                   testbit := f.crbit
                   bitvalue := AsmCondFlagTF[f.cond];
                 end;
               else
                 internalerror(200109064);
             end;
         end;
         { load the conditional register in the destination reg }
         list.concat(taicpu.op_reg_reg(A_MFCR,reg));
         { we will move the bit that has to be tested to bit 31 -> rotate }
         { left by bitpos+1 (remember, this is big-endian!)               }
         if bitpos <> 31 then
           inc(bitpos)
         else
           bitpos := 0;
         { extract bit }
         list.concat(taicpu.op_reg_reg_const_const_const(
           A_RLWINM,reg,reg,bitpos,31,31));
         { if we need the inverse, xor with 1 }
         if not bitvalue then
           list.concat(taicpu.op_reg_reg_const(A_XORI,reg,reg,1));
       end;
*)

{ *********** entry/exit code and address loading ************ }

    procedure tcgppc.g_stackframe_entry(list : taasmoutput;localsize : longint);

      begin
        case target_info.system of
          system_powerpc_macos:
            g_stackframe_entry_mac(list,localsize);
          system_powerpc_linux:
            g_stackframe_entry_sysv(list,localsize)
          else
            internalerror(2204001);
        end;
      end;


    procedure tcgppc.g_stackframe_entry_sysv(list : taasmoutput;localsize : longint);
 { generated the entry code of a procedure/function. Note: localsize is the }
 { sum of the size necessary for local variables and the maximum possible   }
 { combined size of ALL the parameters of a procedure called by the current }
 { one                                                                      }
     var regcounter: TRegister;
         href : treference;

      begin
        if (localsize mod 8) <> 0 then internalerror(58991);
 { CR and LR only have to be saved in case they are modified by the current }
 { procedure, but currently this isn't checked, so save them always         }
        { following is the entry code as described in "Altivec Programming }
        { Interface Manual", bar the saving of AltiVec registers           }
        a_reg_alloc(list,STACK_POINTER_REG);
        a_reg_alloc(list,R_0);
        { allocate registers containing reg parameters }
        for regcounter := R_3 to R_10 do
          a_reg_alloc(list,regcounter);
        { save return address... }
        list.concat(taicpu.op_reg_reg(A_MFSPR,R_0,R_LR));
        { ... in caller's frame }
        reference_reset_base(href,STACK_POINTER_REG,4);
        list.concat(taicpu.op_reg_ref(A_STW,R_0,href));
        a_reg_dealloc(list,R_0);
        a_reg_alloc(list,R_11);
        { save end of fpr save area }
        list.concat(taicpu.op_reg_reg_const(A_ORI,R_11,STACK_POINTER_REG,0));
        a_reg_alloc(list,R_12);
        { 0 or 8 based on SP alignment }
        list.concat(taicpu.op_reg_reg_const_const_const(A_RLWINM,
          R_12,STACK_POINTER_REG,0,28,28));
        { add in stack length }
        list.concat(taicpu.op_reg_reg_const(A_SUBFIC,R_12,R_12,
          -localsize));
        { establish new alignment }
        list.concat(taicpu.op_reg_reg_reg(A_STWUX,STACK_POINTER_REG,STACK_POINTER_REG,R_12));
        a_reg_dealloc(list,R_12);
        { save floating-point registers }
        { !!! has to be optimized: only save registers that are used }
        list.concat(taicpu.op_sym_ofs(A_BL,newasmsymbol('_savefpr_14'),0));
        { compute end of gpr save area }
        list.concat(taicpu.op_reg_reg_const(A_ADDI,R_11,R_11,-144));
        { save gprs and fetch GOT pointer }
        { !!! has to be optimized: only save registers that are used }
        list.concat(taicpu.op_sym_ofs(A_BL,newasmsymbol('_savegpr_14_go'),0));
        a_reg_alloc(list,R_31);
        { place GOT ptr in r31 }
        list.concat(taicpu.op_reg_reg(A_MFSPR,R_31,R_LR));
        { save the CR if necessary ( !!! always done currently ) }
        { still need to find out where this has to be done for SystemV
        a_reg_alloc(list,R_0);
        list.concat(taicpu.op_reg_reg(A_MFSPR,R_0,R_CR);
        list.concat(taicpu.op_reg_ref(A_STW,scratch_register,
          new_reference(STACK_POINTER_REG,LA_CR)));
        a_reg_dealloc(list,R_0); }
        { save pointer to incoming arguments }
        list.concat(taicpu.op_reg_reg_const(A_ADDI,R_30,R_11,144));
        { now comes the AltiVec context save, not yet implemented !!! }
      end;


    procedure tcgppc.g_stackframe_entry_mac(list : taasmoutput;localsize : longint);
 { generated the entry code of a procedure/function. Note: localsize is the }
 { sum of the size necessary for local variables and the maximum possible   }
 { combined size of ALL the parameters of a procedure called by the current }
 { one                                                                      }
     var regcounter: TRegister;
         href : treference;

      begin
        if (localsize mod 8) <> 0 then internalerror(58991);
 { CR and LR only have to be saved in case they are modified by the current }
 { procedure, but currently this isn't checked, so save them always         }
        { following is the entry code as described in "Altivec Programming }
        { Interface Manual", bar the saving of AltiVec registers           }
        a_reg_alloc(list,STACK_POINTER_REG);
        a_reg_alloc(list,R_0);
        { allocate registers containing reg parameters }
        for regcounter := R_3 to R_10 do
          a_reg_alloc(list,regcounter);
        { save return address... }
        list.concat(taicpu.op_reg_reg(A_MFSPR,R_0,R_LR));
        { ... in caller's frame }
        reference_reset_base(href,STACK_POINTER_REG,8);
        list.concat(taicpu.op_reg_ref(A_STW,R_0,href));
        a_reg_dealloc(list,R_0);
        { save floating-point registers }
        { !!! has to be optimized: only save registers that are used }
        list.concat(taicpu.op_sym_ofs(A_BL,newasmsymbol('_savef14'),0));
        { save gprs in gpr save area }
        { !!! has to be optimized: only save registers that are used }
        reference_reset_base(href,STACK_POINTER_REG,-220);
        list.concat(taicpu.op_reg_ref(A_STMW,R_13,href));
        { save the CR if necessary ( !!! always done currently ) }
        a_reg_alloc(list,R_0);
        list.concat(taicpu.op_reg_reg(A_MFSPR,R_0,R_CR));
        reference_reset_base(href,stack_pointer_reg,LA_CR);
        list.concat(taicpu.op_reg_ref(A_STW,R_0,href));
        a_reg_dealloc(list,R_0);
        { save pointer to incoming arguments }
        list.concat(taicpu.op_reg_reg_const(A_ORI,R_31,STACK_POINTER_REG,0));
        a_reg_alloc(list,R_12);
        { 0 or 8 based on SP alignment }
        list.concat(taicpu.op_reg_reg_const_const_const(A_RLWINM,
          R_12,STACK_POINTER_REG,0,28,28));
        { add in stack length }
        list.concat(taicpu.op_reg_reg_const(A_SUBFIC,R_12,R_12,
          -localsize));
        { establish new alignment }
        list.concat(taicpu.op_reg_reg_reg(A_STWUX,STACK_POINTER_REG,STACK_POINTER_REG,R_12));
        a_reg_dealloc(list,R_12);
        { now comes the AltiVec context save, not yet implemented !!! }
      end;


    procedure tcgppc.g_restore_frame_pointer(list : taasmoutput);

      begin
 { no frame pointer on the PowerPC (maybe there is one in the SystemV ABI?)}
      end;


    procedure tcgppc.g_return_from_proc(list : taasmoutput;parasize : aword);

      begin
        case target_info.system of
          system_powerpc_macos:
            g_return_from_proc_mac(list,parasize);
          system_powerpc_linux:
            g_return_from_proc_sysv(list,parasize)
          else
            internalerror(2204001);
        end;
      end;


     procedure tcgppc.a_loadaddr_ref_reg(list : taasmoutput;const ref : treference;r : tregister);

       var
         ref2, tmpref: treference;

       begin
         ref2 := ref;
         FixRef(list,ref2);
         if assigned(ref2.symbol) then
           { add the symbol's value to the base of the reference, and if the }
           { reference doesn't have a base, create one                       }
           begin
             reference_reset(tmpref);
             tmpref.offset := ref2.offset;
             tmpref.symbol := ref2.symbol;
             tmpref.symaddr := refs_ha;
             if ref2.base <> R_NO then
               list.concat(taicpu.op_reg_reg_ref(A_ADDIS,r,
                 ref2.base,tmpref))
             else
               list.concat(taicpu.op_reg_ref(A_LIS,r,tmpref));
             tmpref.base := R_NO;
             tmpref.symaddr := refs_l;
             { can be folded with one of the next instructions by the }
             { optimizer probably                                     }
             list.concat(taicpu.op_reg_reg_ref(A_ADDI,r,r,tmpref));
           end
         else if ref2.offset <> 0 Then
           if ref2.base <> R_NO then
             a_op_const_reg_reg(list,OP_ADD,OS_32,ref2.offset,ref2.base,r)
  { FixRef makes sure that "(ref.index <> R_NO) and (ref.offset <> 0)" never}
  { occurs, so now only ref.offset has to be loaded                         }
           else a_load_const_reg(list,OS_32,ref2.offset,r)
         else if ref.index <> R_NO Then
           list.concat(taicpu.op_reg_reg_reg(A_ADD,r,ref2.base,ref2.index))
         else if (ref2.base <> R_NO) and
                 (r <> ref2.base) then
           list.concat(taicpu.op_reg_reg(A_MR,r,ref2.base));
       end;

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

    procedure tcgppc.g_concatcopy(list : taasmoutput;const source,dest : treference;len : aword; delsource,loadref : boolean);

      var
        countreg: TRegister;
        src, dst: TReference;
        lab: tasmlabel;
        count, count2: aword;
        orgsrc, orgdst : boolean;

      begin
{$ifdef extdebug}
        if len > high(longint) then
          internalerror(2002072704);
{$endif extdebug}

        { make sure short loads are handled as optimally as possible }
        if not loadref then
          if (len <= 8) and
             (byte(len) in [1,2,4,8]) then
            begin
              if len < 8 then
                begin
                  a_load_ref_ref(list,int_cgsize(len),source,dest);
                  if delsource then
                    reference_release(exprasmlist,source);
                end
              else
                begin
                  a_reg_alloc(list,R_F0);
                  a_loadfpu_ref_reg(list,OS_F64,source,R_F0);
                  if delsource then
                    reference_release(exprasmlist,source);
                  a_loadfpu_reg_ref(list,OS_F64,R_F0,dest);
                end;
              exit;
            end;

        { make sure source and dest are valid }
        src := source;
        fixref(list,src);
        dst := dest;
        fixref(list,dst);
        reference_reset(src);
        reference_reset(dst);
        { load the address of source into src.base }
        if loadref then
          begin
            src.base := get_scratch_reg_address(list);
            a_load_ref_reg(list,OS_32,source,src.base);
            orgsrc := false;
          end
        else if assigned(source.symbol) or
                ((source.offset + longint(len)) > high(smallint)) then
          begin
            src.base := get_scratch_reg_address(list);
            a_loadaddr_ref_reg(list,source,src.base);
            orgsrc := false;
          end
        else
          begin
            src := source;
            orgsrc := true;
          end;
        if not orgsrc and delsource then
          reference_release(exprasmlist,source);
        { load the address of dest into dst.base }
        if assigned(dest.symbol) or
           ((dest.offset + longint(len)) > high(smallint)) then
          begin
            dst.base := get_scratch_reg_address(list);
            a_loadaddr_ref_reg(list,dest,dst.base);
            orgdst := false;
          end
        else
          begin
            dst := dest;
            orgdst := true;
          end;

        count := len div 8;
        if count > 4 then
          { generate a loop }
          begin
            { the offsets are zero after the a_loadaddress_ref_reg and just }
            { have to be set to 8. I put an Inc there so debugging may be   }
            { easier (should offset be different from zero here, it will be }
            { easy to notice in the generated assembler                     }
            inc(dst.offset,8);
            inc(src.offset,8);
            list.concat(taicpu.op_reg_reg_const(A_SUBI,src.base,src.base,8));
            list.concat(taicpu.op_reg_reg_const(A_SUBI,dst.base,dst.base,8));
            countreg := get_scratch_reg_int(list);
            a_load_const_reg(list,OS_32,count,countreg);
            { explicitely allocate R_0 since it can be used safely here }
            { (for holding date that's being copied)                    }
            a_reg_alloc(list,R_F0);
            getlabel(lab);
            a_label(list, lab);
            list.concat(taicpu.op_reg_reg_const(A_SUBIC_,countreg,countreg,1));
            list.concat(taicpu.op_reg_ref(A_LFDU,R_F0,src));
            list.concat(taicpu.op_reg_ref(A_STFDU,R_F0,dst));
            a_jmp(list,A_BC,C_NE,0,lab);
            free_scratch_reg(list,countreg);
            a_reg_dealloc(list,R_F0);
            len := len mod 8;
          end;

        count := len div 8;
        if count > 0 then
          { unrolled loop }
          begin
            a_reg_alloc(list,R_F0);
            for count2 := 1 to count do
              begin
                a_loadfpu_ref_reg(list,OS_F64,src,R_F0);
                a_loadfpu_reg_ref(list,OS_F64,R_F0,dst);
                inc(src.offset,8);
                inc(dst.offset,8);
              end;
            a_reg_dealloc(list,R_F0);
            len := len mod 8;
          end;

        if (len and 4) <> 0 then
          begin
            a_reg_alloc(list,R_0);
            a_load_ref_reg(list,OS_32,src,R_0);
            a_load_reg_ref(list,OS_32,R_0,dst);
            inc(src.offset,4);
            inc(dst.offset,4);
            a_reg_dealloc(list,R_0);
          end;
       { copy the leftovers }
       if (len and 2) <> 0 then
         begin
           a_reg_alloc(list,R_0);
           a_load_ref_reg(list,OS_16,src,R_0);
           a_load_reg_ref(list,OS_16,R_0,dst);
           inc(src.offset,2);
           inc(dst.offset,2);
           a_reg_dealloc(list,R_0);
         end;
       if (len and 1) <> 0 then
         begin
           a_reg_alloc(list,R_0);
           a_load_reg_ref(list,OS_16,R_0,dst);
           a_load_ref_reg(list,OS_8,src,R_0);
           a_load_reg_ref(list,OS_8,R_0,dst);
           a_reg_dealloc(list,R_0);
         end;
       if orgsrc then
         begin
           if delsource then
             reference_release(exprasmlist,source);
         end
       else
         free_scratch_reg(list,src.base);
       if not orgdst then
         free_scratch_reg(list,dst.base);
      end;


    procedure tcgppc.g_overflowcheck(list: taasmoutput; const p: tnode);

      var
         hl : tasmlabel;
      begin
         if not(cs_check_overflow in aktlocalswitches) then
          exit;
         getlabel(hl);
         if not ((p.resulttype.def.deftype=pointerdef) or
                ((p.resulttype.def.deftype=orddef) and
                 (torddef(p.resulttype.def).typ in [u64bit,u16bit,u32bit,u8bit,uchar,
                                                  bool8bit,bool16bit,bool32bit]))) then
           begin
             list.concat(taicpu.op_reg(A_MCRXR,R_CR7));
             a_jmp(list,A_BC,C_OV,7,hl)
           end
         else
           a_jmp_cond(list,OC_AE,hl);
         a_call_name(list,'FPC_OVERFLOW');
         a_label(list,hl);
      end;


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

    procedure tcgppc.g_return_from_proc_sysv(list : taasmoutput;parasize : aword);

      var
        regcounter: TRegister;

      begin
        { release parameter registers }
        for regcounter := R_3 to R_10 do
          a_reg_dealloc(list,regcounter);
        { AltiVec context restore, not yet implemented !!! }

        { address of gpr save area to r11 }
        list.concat(taicpu.op_reg_reg_const(A_ADDI,R_11,R_31,-144));
        { restore gprs }
        list.concat(taicpu.op_sym_ofs(A_BL,newasmsymbol('_restgpr_14'),0));
        { address of fpr save area to r11 }
        list.concat(taicpu.op_reg_reg_const(A_ADDI,R_11,R_11,144));
        { restore fprs and return }
        list.concat(taicpu.op_sym_ofs(A_BL,newasmsymbol('_restfpr_14_x'),0));
      end;


    procedure tcgppc.g_return_from_proc_mac(list : taasmoutput;parasize : aword);

      var
        regcounter: TRegister;
        href : treference;
      begin
        { release parameter registers }
        for regcounter := R_3 to R_10 do
          a_reg_dealloc(list,regcounter);
        { AltiVec context restore, not yet implemented !!! }

        { restore SP }
        list.concat(taicpu.op_reg_reg_const(A_ORI,STACK_POINTER_REG,R_31,0));
        { restore gprs }
        reference_reset_base(href,STACK_POINTER_REG,-220);
        list.concat(taicpu.op_reg_ref(A_LMW,R_13,href));
        { restore return address ... }
        reference_reset_base(href,STACK_POINTER_REG,8);
        list.concat(taicpu.op_reg_ref(A_LWZ,R_0,href));
        { ... and return from _restf14 }
        list.concat(taicpu.op_sym_ofs(A_B,newasmsymbol('_restf14'),0));
      end;


    procedure tcgppc.fixref(list: taasmoutput; var ref: treference);

       begin
         If (ref.base <> R_NO) then
           begin
             if (ref.index <> R_NO) and
                ((ref.offset <> 0) or assigned(ref.symbol)) then
               begin
                 if not assigned(ref.symbol) and
                    (cardinal(ref.offset-low(smallint)) <=
                      high(smallint)-low(smallint)) then
                   begin
                     list.concat(taicpu.op_reg_reg_const(
                       A_ADDI,ref.base,ref.base,ref.offset));
                     ref.offset := 0;
                   end
                 else
                   begin
                     list.concat(taicpu.op_reg_reg_reg(
                       A_ADD,ref.base,ref.base,ref.index));
                     ref.index := R_NO;
                   end;
               end
           end
         else
           begin
             ref.base := ref.index;
             ref.index := R_NO
           end
       end;


    { find out whether a is of the form 11..00..11b or 00..11...00. If }
    { that's the case, we can use rlwinm to do an AND operation        }
    function tcgppc.get_rlwi_const(a: longint; var l1, l2: longint): boolean;

      var
        temp, testbit: longint;
        compare: boolean;

      begin
        get_rlwi_const := false;
        if (a = 0) or (a = $ffffffff) then
          exit;
        { start with the lowest bit }
        testbit := 1;
        { check its value }
        compare := boolean(a and testbit);
        { find out how long the run of bits with this value is            }
        { (it's impossible that all bits are 1 or 0, because in that case }
        { this function wouldn't have been called)                        }
        l1 := 31;
        while (((a and testbit) <> 0) = compare) do
          begin
            testbit := testbit shl 1;
            dec(l1);
          end;

        { check the length of the run of bits that comes next }
        compare := not compare;
        l2 := l1;
        while (((a and testbit) <> 0) = compare) and
               (l2 >= 0) do
          begin
            testbit := testbit shl 1;
            dec(l2);
          end;

        { and finally the check whether the rest of the bits all have the }
        { same value                                                      }
        compare := not compare;
        temp := l2;
        if temp >= 0 then
          if (a shr (31-temp)) <> ((-ord(compare)) shr (31-temp)) then
            exit;

        { we have done "not(not(compare))", so compare is back to its   }
        { initial value. If the lowest bit was 0, a is of the form      }
        { 00..11..00 and we need "rlwinm reg,reg,0,l2+1,l1", (+1        }
        { because l2 now contains the position of the last zero of the  }
        { first run instead of that of the first 1) so switch l1 and l2 }
        { in that case (we will generate "rlwinm reg,reg,0,l1,l2")      }
        if not compare then
          begin
            temp := l1;
            l1 := l2+1;
            l2 := temp;
          end
        else
          { otherwise, l1 currently contains the position of the last   }
          { zero instead of that of the first 1 of the second run -> +1 }
          inc(l1);
        { the following is the same as "if l1 = -1 then l1 := 31;" }
        l1 := l1 and 31;
        l2 := l2 and 31;
        get_rlwi_const := true;
      end;


    procedure tcgppc.a_load_store(list:taasmoutput;op: tasmop;reg:tregister;
       ref: treference);

      var
        tmpreg: tregister;
        tmpref: treference;

      begin
        if assigned(ref.symbol) then
          begin
            tmpreg := get_scratch_reg_address(list);
            reference_reset(tmpref);
            tmpref.symbol := ref.symbol;
            tmpref.symaddr := refs_ha;
            if ref.base <> R_NO then
              list.concat(taicpu.op_reg_reg_ref(A_ADDIS,tmpreg,
                ref.base,tmpref))
            else
              list.concat(taicpu.op_reg_ref(A_LIS,tmpreg,tmpref));
            ref.base := tmpreg;
            ref.symaddr := refs_l;
          end;
        list.concat(taicpu.op_reg_ref(op,reg,ref));
        if assigned(ref.symbol) then
          free_scratch_reg(list,tmpreg);
      end;


    procedure tcgppc.a_jmp(list: taasmoutput; op: tasmop; c: tasmcondflag;
                crval: longint; l: tasmlabel);
      var
        p: taicpu;

      begin
        p := taicpu.op_sym(op,newasmsymbol(l.name));
        if op <> A_B then
          create_cond_norm(c,crval,p.condition);
        p.is_jmp := true;
        list.concat(p)
      end;


    procedure tcg64fppc.a_op64_reg_reg(list : taasmoutput;op:TOpCG;regsrc,regdst : tregister64);
      begin
        a_op64_reg_reg_reg(list,op,regsrc,regdst,regdst);
      end;


    procedure tcg64fppc.a_op64_const_reg(list : taasmoutput;op:TOpCG;value : qword;reg : tregister64);
      begin
        a_op64_const_reg_reg(list,op,value,reg,reg);
      end;


    procedure tcg64fppc.a_op64_reg_reg_reg(list: taasmoutput;op:TOpCG;regsrc1,regsrc2,regdst : tregister64);
      begin
        case op of
          OP_AND,OP_OR,OP_XOR:
            begin
              cg.a_op_reg_reg_reg(list,op,OS_32,regsrc1.reglo,regsrc2.reglo,regdst.reglo);
              cg.a_op_reg_reg_reg(list,op,OS_32,regsrc1.reghi,regsrc2.reghi,regdst.reghi);
            end;
          OP_ADD:
            begin
              list.concat(taicpu.op_reg_reg_reg(A_ADDC,regdst.reglo,regsrc1.reglo,regsrc2.reglo));
              list.concat(taicpu.op_reg_reg_reg(A_ADDE,regdst.reghi,regsrc1.reghi,regsrc2.reghi));
            end;
          OP_SUB:
            begin
              list.concat(taicpu.op_reg_reg_reg(A_SUBC,regdst.reglo,regsrc2.reglo,regsrc1.reglo));
              list.concat(taicpu.op_reg_reg_reg(A_SUBFE,regdst.reghi,regsrc1.reghi,regsrc2.reghi));
            end;
          else
            internalerror(2002072801);
        end;
      end;


    procedure tcg64fppc.a_op64_const_reg_reg(list: taasmoutput;op:TOpCG;value : qword;regsrc,regdst : tregister64);

      const
        ops: array[boolean,1..3] of tasmop = ((A_ADDIC,A_ADDC,A_ADDZE),
                                              (A_SUBIC,A_SUBC,A_ADDME));
      var
        tmpreg: tregister;
        tmpreg64: tregister64;
        issub: boolean;
      begin
        case op of
          OP_AND,OP_OR,OP_XOR:
            begin
              cg.a_op_const_reg_reg(list,op,OS_32,cardinal(value),regsrc.reglo,regdst.reglo);
              cg.a_op_const_reg_reg(list,op,OS_32,value shr 32,regsrc.reghi,
                regdst.reghi);
            end;
          OP_ADD, OP_SUB:
            begin
              if (longint(value) <> 0) then
                begin
                  issub := op = OP_SUB;
                  if (longint(value) >= -32768) and
                     (longint(value) <= 32767) then
                    begin
                      list.concat(taicpu.op_reg_reg_const(ops[issub,1],
                        regdst.reglo,regsrc.reglo,aword(value)));
                      list.concat(taicpu.op_reg_reg(ops[issub,3],
                        regdst.reghi,regsrc.reghi));
                    end
                  else if ((value shr 32) = 0) then
                    begin
                      tmpreg := cg.get_scratch_reg_int(list);
                      cg.a_load_const_reg(list,OS_32,cardinal(value),tmpreg);
                      list.concat(taicpu.op_reg_reg_reg(ops[issub,2],
                        regdst.reglo,regsrc.reglo,tmpreg));
                      cg.free_scratch_reg(list,tmpreg);
                      list.concat(taicpu.op_reg_reg(ops[issub,3],
                        regdst.reghi,regsrc.reghi));
                    end
                  else
                    begin
                      tmpreg64.reglo := cg.get_scratch_reg_int(list);
                      tmpreg64.reghi := cg.get_scratch_reg_int(list);
                      a_load64_const_reg(list,value,tmpreg64);
                      a_op64_reg_reg_reg(list,op,tmpreg64,regsrc,regdst);
                      cg.free_scratch_reg(list,tmpreg64.reghi);
                      cg.free_scratch_reg(list,tmpreg64.reglo);
                    end
                end
              else
                cg.a_op_const_reg_reg(list,op,OS_32,value shr 32,regsrc.reghi,
                  regdst.reghi);
            end;
          else
            internalerror(2002072802);
        end;
      end;


begin
  cg := tcgppc.create;
  cg64 :=tcg64fppc.create;
end.
{
  $Log$
  Revision 1.32  2002-08-02 11:10:42  jonas
    * some misc constant fixes

  Revision 1.31  2002/07/30 20:50:44  florian
    * the code generator knows now if parameters are in registers

  Revision 1.30  2002/07/29 21:23:44  florian
    * more fixes for the ppc
    + wrappers for the tcnvnode.first_* stuff introduced

  Revision 1.29  2002/07/28 21:38:30  florian
    - removed debug code which was commited by accident

  Revision 1.28  2002/07/28 21:34:31  florian
    * more powerpc fixes
    + dummy tcgvecnode

  Revision 1.27  2002/07/28 16:01:59  jonas
    + tcg64fppc.a_op64_const_reg_reg() and tcg64fppc.a_op64_reg_reg_reg()
    * several fixes, most notably in a_load_reg_reg(): it didn't do any
      conversion from smaller to larger sizes or vice versa
    * some small optimizations

  Revision 1.26  2002/07/27 19:59:29  jonas
    * fixed a_loadaddr_ref_reg()
    * fixed g_flags2reg()
    * optimized g_concatcopy()

  Revision 1.25  2002/07/26 21:15:45  florian
    * rewrote the system handling

  Revision 1.24  2002/07/21 17:00:23  jonas
    * make sure we use rlwi* when possible instead of andi.

  Revision 1.23  2002/07/11 14:41:34  florian
    * start of the new generic parameter handling

  Revision 1.22  2002/07/11 07:38:28  jonas
    + tcg64fpc implementation (only a_op64_reg_reg and a_op64_const_reg for
      now)
    * fixed and improved tcgppc.a_load_const_reg
    * improved tcgppc.a_op_const_reg, tcgppc.a_cmp_const_reg_label
    * A_CMP* -> A_CMPW* (this means that 32bit compares should be done)

  Revision 1.21  2002/07/09 19:45:01  jonas
    * unarynminus and shlshr node fixed for 32bit and smaller ordinals
    * small fixes in the assembler writer
    * changed scratch registers, because they were used by the linker (r11
      and r12) and by the abi under linux (r31)

  Revision 1.20  2002/07/07 09:44:31  florian
    * powerpc target fixed, very simple units can be compiled

  Revision 1.19  2002/05/20 13:30:41  carl
  * bugfix of hdisponen (base must be set, not index)
  * more portability fixes

  Revision 1.18  2002/05/18 13:34:26  peter
    * readded missing revisions

  Revision 1.17  2002/05/16 19:46:53  carl
  + defines.inc -> fpcdefs.inc to avoid conflicts if compiling by hand
  + try to fix temp allocation (still in ifdef)
  + generic constructor calls
  + start of tassembler / tmodulebase class cleanup

  Revision 1.14  2002/05/13 19:52:46  peter
    * a ppcppc can be build again

  Revision 1.13  2002/04/20 21:41:51  carl
  * renamed some constants

  Revision 1.12  2002/04/06 18:13:01  jonas
    * several powerpc-related additions and fixes

  Revision 1.11  2002/01/02 14:53:04  jonas
    * fixed small bug in a_jmp_flags

}