freepascal.compiler/compiler/powerpc/cgcpu.pas

{
    $Id$
    Copyright (c) 1998-2000 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;

  interface

    uses
       cgbase,cgobj,aasm,cpuasm,cpubase,cpuinfo;

    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_reg(list : taasmoutput;size : tcgsize;r : tregister;nr : longint);override;
        procedure a_param_const(list : taasmoutput;size : tcgsize;a : aword;nr : longint);override;
        procedure a_param_ref(list : taasmoutput;size : tcgsize;const r : treference;nr : longint);override;
        procedure a_paramaddr_ref(list : taasmoutput;const r : treference;nr : longint);override;


        procedure a_call_name(list : taasmoutput;const s : string;
          offset : longint);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;

        { 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;

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

        procedure a_jmp_cond(list : taasmoutput;cond : TOpCmp;l: pasmlabel);
        procedure g_flags2reg(list: taasmoutput; const f: TAsmCond; 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_loadaddress_ref_reg(list : taasmoutput;const ref2 : treference;r : tregister);override;

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


        private

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

        procedure a_op_reg_reg_const32(list: taasmoutput; op: TOpCg;
          dst, src: tregister; a: aword);

        procedure a_op_reg_reg_reg(list: taasmoutput; op: TOpCg; dst, src1,
          src2: tregister);

        { 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(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: tasmcondflags; l: pasmlabel);

     end;

const
{
  TOpCG2AsmOp: Array[topcg] of TAsmOp = (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);
}

  TOpCG2AsmOpConstLo: Array[topcg] of TAsmOp = (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_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 TAsmCondFlags = (CF_NONE,CF_EQ,CF_GT,
                       CF_LT,CF_GE,CF_LE,CF_NE,CF_LE,CF_NG,CF_GE,CF_NL);

  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)));

  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)));


  implementation

    uses
       globtype,globals,verbose,systems,cutils;

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

    procedure tcgppc.a_param_reg(list : taasmoutput;size : tcgsize;r : tregister;nr : longint);

      var
        ref: treference;

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


    procedure tcgppc.a_param_const(list : taasmoutput;size : tcgsize;a : aword;nr : longint);

      var
        ref: treference;

      begin
  {$ifdef para_sizes_known}
        if (nr <= max_param_regs_int) then
          a_load_const_reg(list,size,a,param_regs_int[nr])
        else
          begin
            reset_reference(ref);
            ref.base := stack_pointer;
            ref.offset := LinkageAreaSize+para_size_till_now;
            a_load_const_ref(list,size,a,ref);
          end;
  {$endif para_sizes_known}
      end;


    procedure tcgppc.a_param_ref(list : taasmoutput;size : tcgsize;const r : treference;nr : longint);

      var
        ref: treference;
        tmpreg: tregister;

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


    procedure tcgppc.a_paramaddr_ref(list : taasmoutput;const r : treference;nr : longint);

      var
        ref: treference;
        tmpreg: tregister;

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

{ calling a code fragment by name }

    procedure tcgppc.a_call_name(list : taasmoutput;const s : string;
      offset : longint);

      begin
 { save our RTOC register value. Only necessary when doing pointer based    }
 { calls or cross TOC calls, but currently done always                      }
         list.concat(taicpu.op_reg_ref(A_STW,R_RTOC,
           new_reference(stack_pointer,LA_RTOC)));
         list.concat(taicpu.op_sym(A_BL,newasmsymbol(s)));
         list.concat(taicpu.op_reg_ref(A_LWZ,R_RTOC,
           new_reference(stack_pointer,LA_RTOC)));
      end;

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

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

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

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

       var
         op: TAsmOp;
         ref2: TReference;

       begin
         ref2 := ref;
         FixRef(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 = OS_64 then
           internalerror(200109236);
         op := storeinstr[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);

       var
         op: tasmop;
         tmpreg: tregister;
         ref2, tmpref: treference;

       begin
         if ref.is_immediate then
           a_load_const_reg(list,size,ref.offset,reg)
         else
           begin
             ref2 := ref;
             fixref(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;
       end;

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

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

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

       var
         scratch_register: TRegister;

       begin
         Case Op of
           OP_DIV, OP_IDIV, OP_IMUL, OP_MUL:
             If (Op = OP_IMUL) And (longint(a) >= -32768) And
                (longint(a) <= 32767) Then
               list.concat(taicpu.op_reg_reg_const(A_MULLI,reg,reg,a))
             Else
               Begin
                 scratch_register := get_scratch_reg(list);
                 a_load_const_reg(list,OS_32,a,scratch_register);
                 list.concat(taicpu.op_reg_reg_reg(TOpCG2AsmOpConstLo[Op],
                   reg,scratch_register,reg));
                 free_scratch_reg(list,scratch_register);
               End;
           OP_ADD, OP_AND, OP_OR, OP_SUB,OP_XOR:
             a_op_reg_reg_const32(list,op,reg,reg,a)
           OP_SHL,OP_SHR,OP_SAR:
             Begin
               if (a and 31) <> 0 Then
                 list.concat(taicpu.op_reg_reg_const(
                   TOpCG2AsmOpConstLo[Op],reg,reg,a and 31));
               If (a shr 5) <> 0 Then
                 InternalError(68991);
             End
           Else InternalError(68992);
         end;
       end;

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

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

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

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

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

        begin
          signed := cmp_op in [OC_GT,OC_LT,OC_GTE,OC_LTE];
          if signed then
            if (longint(a) >= low(smallint)) and (longint(a) <= high(smallint)) Then
              list.concat(taicpu.op_reg_reg_const(A_CMPI,R_CR0,reg,a))
            else
              begin
                scratch_register := get_scratch_reg(list);
                a_load_const_reg(list,OS_32,a,scratch_register);
                list.concat(taicpu.op_reg_reg_reg(A_CMP,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_CMPLI,R_CR0,reg,a))
            else
              begin
                scratch_register := get_scratch_reg(list);
                a_load_const_reg(list,OS_32,a,scratch_register);
                list.concat(taicpu.op_reg_reg_reg(A_CMPL,R_CR0,reg,scratch_register));
                free_scratch_reg(list,scratch_register);
              end;
          a_jmp(list,A_BC,TOpCmp2AsmCond[cmp_op],l);
        end;


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

        var p: paicpu;
            op: tasmop;

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

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

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


     procedure tcgppc.g_flags2reg(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 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.create(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.create(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.create(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_os.id of
          os_powerpc_macos:
            g_stackframe_entry_mac(list,localsize);
          os_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;

      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);
        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 }
        list.concat(taicpu.op_reg_ref(A_STW,R_0,new_reference(STACK_POINTER,4)));
        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,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,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,STACK_POINTER,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,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;

      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);
        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 }
        list.concat(taicpu.op_reg_ref(A_STW,R_0,new_reference(STACK_POINTER,8)));
        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 }
        list.concat(taicpu.op_reg_ref(A_STMW,R_13,new_reference(STACK_POINTER,-220)));
        { 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));
        list.concat(taicpu.op_reg_ref(A_STW,R_0,
          new_reference(stack_pointer,LA_CR)));
        a_reg_dealloc(list,R_0);
        { save pointer to incoming arguments }
        list.concat(taicpu.op_reg_reg_const(A_ORI,R_31,STACK_POINTER,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,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,STACK_POINTER,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_os.id of
          os_powerpc_macos:
            g_return_from_proc_mac(list,parasize);
          os_powerpc_linux:
            g_return_from_proc_sysv(list,parasize)
          else
            internalerror(2204001);
        end;
      end;

     procedure tcgppc.a_loadaddress_ref_reg(list : taasmoutput;const ref2 : treference;r : tregister);

       var tmpreg: tregister;
           ref, tmpref: treference;

       begin
         ref := ref2;
         FixRef(ref);
         if assigned(ref.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
             tmpreg := get_scratch_reg(list);
             reset_reference(tmpref);
             tmpref.symbol := ref.symbol;
             tmpref.symaddr := refs_ha;
             tmpref.is_immediate := true;
             if ref.base <> R_NO then
               list.concat(taicpu.op_reg_reg_ref(A_ADDIS,tmpreg,
                 ref.base,newreference(tmpref)))
             else
               list.concat(taicpu.op_reg_ref(A_LIS,tmpreg,
                  newreference(tmpref)));
             ref.base := tmpreg;
             ref.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,tmpreg,tmpreg,
                newreference(tmpref)));
           end;
         if ref.offset <> 0 Then
           if ref.base <> R_NO then
             a_op_reg_reg_const32(list,OP_ADD,r,ref.base,ref.offset)
  { 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, ref.offset, r)
         else
           if ref.index <> R_NO Then
             list.concat(taicpu.op_reg_reg_reg(A_ADD,r,ref.base,ref.index))
           else
             if r <> ref.base then
               list.concat(taicpu.op_reg_reg(A_MR,r,ref.base));
         if assigned(ref.symbol) then
           free_scratch_reg(list,tmpreg);
       end;

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

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

      var
        p: paicpu;
        countreg, tempreg: TRegister;
        src, dst: TReference;
        lab: PAsmLabel;
        count, count2: aword;

      begin
        { make sure source and dest are valid }
        src := source;
        fixref(src);
        dst := dest;
        fixref(dst);
        reset_reference(src);
        reset_reference(dst);
        { load the address of source into src.base }
        src.base := get_scratch_reg(list);
        if loadref then
          a_load_ref_reg(list,OS_32,source,src.base)
        else a_loadaddress_ref_reg(list,source,src.base);
        if delsource then
          del_reference(list,source);
        { load the address of dest into dst.base }
        dst.base := get_scratch_reg(list);
        a_loadaddress_ref_reg(list,dest,dst.base);
        count := len div 4;
        if count > 3 then
          { generate a loop }
          begin
            { the offsets are zero after the a_loadaddress_ref_reg and just }
            { have to be set to 4. 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 genreated assembler                     }
            Inc(dst.offset,4);
            Inc(src.offset,4);
            list.concat(taicpu.op_reg_reg_const(A_SUBI,src.base,src.base,4));
            list.concat(taicpu.op_reg_reg_const(A_SUBI,dst.base,dst.base,4));
            countreg := get_scratch_reg(list);
            a_load_const_reg(list,OS_32,count-1,countreg);
            { explicitely allocate R_0 since it can be used safely here }
            { (for holding date that's being copied)                    }
            tempreg := R_0;
            a_reg_alloc(list,R_0);
            getlabel(lab);
            a_label(list, lab);
            list.concat(taicpu.op_reg_ref(A_LWZU,tempreg,
              newreference(src)));
            list.concat(taicpu.op_reg_reg_const(A_CMPI,R_CR0,countreg,0));
            list.concat(taicpu.op_reg_ref(A_STWU,tempreg,newreference(dst)));
            list.concat(taicpu.op_reg_reg_const(A_SUBI,countreg,countreg,1));
            a_jmp(list,A_BC,CF_NE,lab);
            free_scratch_reg(list,countreg);
          end
        else
          { unrolled loop }
          begin
            tempreg := get_scratch_reg(list);
            for count2 := 1 to count do
              begin
                a_load_ref_reg(list,OS_32,src,tempreg);
                a_load_reg_ref(list,OS_32,tempreg,dst);
                inc(src.offset,4);
                inc(dst.offset,4);
              end
          end;
       { copy the leftovers }
       if (len and 2) <> 0 then
         begin
           a_load_ref_reg(list,OS_16,src,tempreg);
           a_load_reg_ref(list,OS_16,tempreg,dst);
           inc(src.offset,2);
           inc(dst.offset,2);
         end;
       if (len and 1) <> 0 then
         begin
           a_load_ref_reg(list,OS_8,src,tempreg);
           a_load_reg_ref(list,OS_8,tempreg,dst);
         end;
       a_reg_dealloc(list,tempreg);
       free_scratch_reg(list,src.base);
       free_scratch_reg(list,dst.base);
      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;

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


    procedure tcgppc.fixref(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
               Internalerror(58992)
           end
         else
           begin
             ref.base := ref.index;
             ref.index := R_NO
           end
       end;


    procedure tcgppc.a_op_reg_reg_const32(list: taasmoutput; op: TOpCg;
                       dst, src: tregister; a: aword): boolean;
      var
        l1,l2: longint;

      { 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: boolean;

        var
          temp, testbit: longint;
          compare: boolean;

        begin
          get_rlwi_const := false;
          { 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;

      var
        oplo, ophi: tasmop;
        scratchreg: tregister;
        useReg: boolean;

      begin
        ophi := TOpCG2AsmOpConstHi[op];
        oplo := TOpCG2AsmOpConstLo[op];
        { 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 (longint(a) >= low(smallint)) and
           (longint(a) <= high(smallint)) then
          begin
            list.concat(taicpu.op_reg_reg_const(oplo,reg1,reg2,a));
            exit;
          end;
        { all basic constant instructions also have a shifted form that }
        { works only on the highest 16bits, so if low(a) is 0, we can   }
        { use that one                                                  }
        if (low(a) = 0) then
          begin
            list.concat(taicpu.op_reg_reg(ophi,reg1,reg2,high(a)));
            exit;
          end;
        { otherwise, the instructions we can generate depend on the }
        { operation                                                 }
        useReg := false;
        case op of
          OP_ADD,OP_SUB:
            begin
              list.concat(taicpu.op_reg_reg_const(oplo,reg1,reg2,low(a)));
              list.concat(taicpu.op_reg_reg_const(ophi,reg1,reg1,
                high(a) + ord(smallint(a) < 0)));
            end;
          OP_OR:
            { try to use rlwimi }
            if get_rlwi_const then
              begin
                if reg1 <> reg2 then
                  list.concat(taicpu.op_reg_reg(A_MR,reg1,reg2));
                scratch_reg := get_scratch_reg(list);
                list.concat(taicpu.op_reg_const(A_LI,scratch_reg,-1));
                list.concat(taicpu.op_reg_reg_const_const_const(A_RLWIMI,reg1,
                  reg2,0,l1,l2));
                free_scratch_reg(list,scratch_reg);
              end
            else
              useReg := true;
          OP_AND:
            { try to use rlwinm }
            if get_rlwi_const then
              list.concat(taicpu.op_reg_reg_const_const_const(A_RLWINM,reg1,
                reg2,0,l1,l2))
            else
              useReg := true;
          OP_XOR:
            useReg := true;
          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(list);
            a_load_const_reg(list,OS_32,a,scratchreg);
            a_op_reg_reg_reg(list,op,reg1,scratchreg,reg2);
            free_scratch_reg(list,scratchreg);
          end;
      end;


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

      const
        op_reg_reg_opcg2asmop: array[TOpCG] of tasmop =
          (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],size,dst,dst));
           else
             list.concat(taicpu.op_reg_reg_reg(op_reg_reg_opcg2asmop[op],size,dst,src1,src2));
       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(list);
            reset_reference(tmpref);
            tmpref.symbol := ref.symbol;
            tmpref.symaddr := refs_ha;
            tmpref.is_immediate := true;
            if ref.base <> R_NO then
              list.concat(taicpu.op_reg_reg_ref(A_ADDIS,tmpreg,
                ref.base,newreference(tmpref)))
            else
              list.concat(taicpu.op_reg_ref(A_LIS,tmpreg,
                 newreference(tmpref)));
            ref.base := tmpreg;
            ref.symaddr := refs_l;
          end;
        list.concat(taicpu.op_reg_ref(op,reg,newreference(ref)));
        if assigned(ref.symbol) then
          free_scratch_reg(list,tmpreg);
      end;


    procedure tcgppc.a_jmp(list: taasmoutput; op: tasmop; c: tasmcondflags;
                l: pasmlabel);
      var
        p: paicpu;

      begin
        p := taicpu.op_sym(op,newasmsymbol(l.name));
        create_cond_norm(c,0,p.condition);
        list.concat(p)
      end;

end.
{
  $Log$
  Revision 1.7  2001-09-29 21:33:30  jonas
    * small optimization

  Revision 1.6  2001/09/28 20:40:05  jonas
    * several additions, almost complete (only some problems with resflags left)

  Revision 1.5  2001/09/16 10:33:21  jonas
    * some fixes to operations with constants

  Revision 1.3  2001/09/06 15:25:55  jonas
    * changed type of tcg from object to class ->  abstract methods are now
      a lot cleaner :)
    + more updates: load_*_loc methods, op_*_* methods, g_flags2reg method
      (if possible with generic implementation and necessary ppc
       implementations)
    * worked a bit further on cgflw, now working on exitnode

  Revision 1.2  2001/09/05 20:21:03  jonas
    * new cgflow based on n386flw with all nodes until forn "translated"
    + a_cmp_loc_*_label methods for tcg
    + base implementatino for a_cmp_ref_*_label methods
    * small bugfixes to powerpc cg

  Revision 1.1  2001/08/26 13:31:04  florian
    * some cg reorganisation
    * some PPC updates

  Revision 1.2  2001/08/26 13:29:33  florian
    * some cg reorganisation
    * some PPC updates

  Revision 1.1  2000/07/13 06:30:12  michael
    + Initial import

  Revision 1.12  2000/04/22 14:25:04  jonas
    * aasm.pas: pai_align instead of pai_align_abstract if cpu <> i386
    + systems.pas: info for macos/ppc
    * new/cgobj.pas: compiles again without newst define
    * new/powerpc/cgcpu: generate different entry/exit code depending on
      whether target_os is MacOs or Linux

  Revision 1.11  2000/01/07 01:14:57  peter
    * updated copyright to 2000

  Revision 1.10  1999/12/24 22:48:10  jonas
    * compiles again

  Revision 1.9  1999/11/05 07:05:56  jonas
    + a_jmp_cond()

  Revision 1.8  1999/10/24 09:22:18  jonas
    + entry/exitcode for SystemV (Linux) and AIX/Mac from the Altivec
      PIM (no AltiVec support yet though)
    * small fix to the a_cmp_* methods

  Revision 1.7  1999/10/20 12:23:24  jonas
    * fixed a_loadaddress_ref_reg (mentioned as ToDo in rev. 1.5)
    * small bugfix in a_load_store

  Revision 1.6  1999/09/15 20:35:47  florian
    * small fix to operator overloading when in MMX mode
    + the compiler uses now fldz and fld1 if possible
    + some fixes to floating point registers
    + some math. functions (arctan, ln, sin, cos, sqrt, sqr, pi) are now inlined
    * .... ???

  Revision 1.5  1999/09/03 13:14:11  jonas
    + implemented some parameter passing methods, but they require
      some more helper routines
    * fix for loading symbol addresses (still needs to be done in a_loadaddress)
    * several changes to the way conditional branches are handled

  Revision 1.4  1999/08/26 14:53:41  jonas
    * first implementation of concatcopy (requires 4 scratch regs)

  Revision 1.3  1999/08/25 12:00:23  jonas
    * changed pai386, paippc and paiapha (same for tai*) to paicpu (taicpu)

  Revision 1.2  1999/08/18 17:05:57  florian
    + implemented initilizing of data for the new code generator
      so it should compile now simple programs

  Revision 1.1  1999/08/06 16:41:11  jonas
    * PowerPC compiles again, several routines implemented in cgcpu.pas
    * added constant to cpubase of alpha and powerpc for maximum
      number of operands
}