freepascal.compiler/compiler/m68k/cpubase.pas

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

    Contains the base types for the m68k

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

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

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

 ****************************************************************************
}
{ This Unit contains the base types for the m68k
}
unit cpubase;

{$i fpcdefs.inc}

interface

uses
  strings,cutils,cclasses,aasmbase,cpuinfo,cginfo;


{*****************************************************************************
                                Assembler Opcodes
*****************************************************************************}

    type
    {  warning: CPU32 opcodes are not fully compatible with the MC68020. }
       { 68000 only opcodes }
       tasmop = (a_abcd,
         a_add,a_adda,a_addi,a_addq,a_addx,a_and,a_andi,
         a_asl,a_asr,a_bcc,a_bcs,a_beq,a_bge,a_bgt,a_bhi,
         a_ble,a_bls,a_blt,a_bmi,a_bne,a_bpl,a_bvc,a_bvs,
         a_bchg,a_bclr,a_bra,a_bset,a_bsr,a_btst,a_chk,
         a_clr,a_cmp,a_cmpa,a_cmpi,a_cmpm,a_dbcc,a_dbcs,a_dbeq,a_dbge,
         a_dbgt,a_dbhi,a_dble,a_dbls,a_dblt,a_dbmi,a_dbne,a_dbra,
         a_dbpl,a_dbt,a_dbvc,a_dbvs,a_dbf,a_divs,a_divu,
         a_eor,a_eori,a_exg,a_illegal,a_ext,a_jmp,a_jsr,
         a_lea,a_link,a_lsl,a_lsr,a_move,a_movea,a_movei,a_moveq,
         a_movem,a_movep,a_muls,a_mulu,a_nbcd,a_neg,a_negx,
         a_nop,a_not,a_or,a_ori,a_pea,a_rol,a_ror,a_roxl,
         a_roxr,a_rtr,a_rts,a_sbcd,a_scc,a_scs,a_seq,a_sge,
         a_sgt,a_shi,a_sle,a_sls,a_slt,a_smi,a_sne,
         a_spl,a_st,a_svc,a_svs,a_sf,a_sub,a_suba,a_subi,a_subq,
         a_subx,a_swap,a_tas,a_trap,a_trapv,a_tst,a_unlk,
         a_rte,a_reset,a_stop,
         { mc68010 instructions }
         a_bkpt,a_movec,a_moves,a_rtd,
         { mc68020 instructions }
         a_bfchg,a_bfclr,a_bfexts,a_bfextu,a_bfffo,
         a_bfins,a_bfset,a_bftst,a_callm,a_cas,a_cas2,
         a_chk2,a_cmp2,a_divsl,a_divul,a_extb,a_pack,a_rtm,
         a_trapcc,a_tracs,a_trapeq,a_trapf,a_trapge,a_trapgt,
         a_traphi,a_traple,a_trapls,a_traplt,a_trapmi,a_trapne,
         a_trappl,a_trapt,a_trapvc,a_trapvs,a_unpk,
         { fpu processor instructions - directly supported only. }
         { ieee aware and misc. condition codes not supported   }
         a_fabs,a_fadd,
         a_fbeq,a_fbne,a_fbngt,a_fbgt,a_fbge,a_fbnge,
         a_fblt,a_fbnlt,a_fble,a_fbgl,a_fbngl,a_fbgle,a_fbngle,
         a_fdbeq,a_fdbne,a_fdbgt,a_fdbngt,a_fdbge,a_fdbnge,
         a_fdblt,a_fdbnlt,a_fdble,a_fdbgl,a_fdbngl,a_fdbgle,a_fdbngle,
         a_fseq,a_fsne,a_fsgt,a_fsngt,a_fsge,a_fsnge,
         a_fslt,a_fsnlt,a_fsle,a_fsgl,a_fsngl,a_fsgle,a_fsngle,
         a_fcmp,a_fdiv,a_fmove,a_fmovem,
         a_fmul,a_fneg,a_fnop,a_fsqrt,a_fsub,a_fsgldiv,
         a_fsflmul,a_ftst,
         a_ftrapeq,a_ftrapne,a_ftrapgt,a_ftrapngt,a_ftrapge,a_ftrapnge,
         a_ftraplt,a_ftrapnlt,a_ftraple,a_ftrapgl,a_ftrapngl,a_ftrapgle,a_ftrapngle,
         { protected instructions }
         a_cprestore,a_cpsave,
         { fpu unit protected instructions                    }
         { and 68030/68851 common mmu instructions            }
         { (this may include 68040 mmu instructions)          }
         a_frestore,a_fsave,a_pflush,a_pflusha,a_pload,a_pmove,a_ptest,
         { useful for assembly language output }
         a_label,a_none,a_dbxx,a_sxx,a_bxx,a_fbxx);

      {# This should define the array of instructions as string }
      op2strtable=array[tasmop] of string[11];

    Const
      {# First value of opcode enumeration }
      firstop = low(tasmop);
      {# Last value of opcode enumeration  }
      lastop  = high(tasmop);

{*****************************************************************************
                                  Registers
*****************************************************************************}

    {$packenum 1}
    type
       Toldregister = (
         R_NO,R_D0,R_D1,R_D2,R_D3,R_D4,R_D5,R_D6,R_D7,
         R_A0,R_A1,R_A2,R_A3,R_A4,R_A5,R_A6,R_SP,
         { PUSH/PULL- quick and dirty hack }
         R_SPPUSH,R_SPPULL,
         { misc. }
         R_CCR,R_FP0,R_FP1,R_FP2,R_FP3,R_FP4,R_FP5,R_FP6,
         R_FP7,R_FPCR,R_SR,R_SSP,R_DFC,R_SFC,R_VBR,R_FPSR,
         R_INTREGISTER,R_FLOATREGISTER);

      Tnewregister=word;

      Tregister=record
        enum:Toldregister;
        number:word;
      end;

      Tsuperregister=byte;
      Tsubregister=byte;

      {# Set type definition for registers }
      tregisterset = set of Toldregister;
      Tsupregset = set of Tsuperregister;
      {$packenum normal}

      { A type to store register locations for 64 Bit values. }
      tregister64 = packed record
        reglo,reghi : tregister;
      end;

      { alias for compact code }
      treg64 = tregister64;


    {New register coding:}

    {Special registers:}
    const
      NR_NO = $0000;  {Invalid register}

    {Normal registers:}

    {General purpose registers:}
      NR_D0 = $0100; NR_D1 = $0200; NR_D2 = $0300;
      NR_D3 = $0400; NR_D4 = $0500; NR_D5 = $0600;
      NR_D6 = $0700; NR_D7 = $0800; NR_A0 = $0900;
      NR_A1 = $0A00; NR_A2 = $0B00; NR_A3 = $0C00;
      NR_A4 = $0D00; NR_A5 = $0E00; NR_A6 = $0F00;
      NR_A7 = $1000;

    {Super registers.}
      RS_D0 = $01; RS_D1 = $02; RS_D2 = $03;
      RS_D3 = $04; RS_D4 = $05; RS_D5 = $06;
      RS_D6 = $07; RS_D7 = $08; RS_A0 = $09;
      RS_A1 = $0A; RS_A2 = $0B; RS_A3 = $0C;
      RS_A4 = $0D; RS_A5 = $0E; RS_A6 = $0F;
      RS_A7 = $10;

     {Sub register numbers:}
                  R_SUBL        = $00;      {8 bits}
                  R_SUBW        = $01;      {16 bits}
                  R_SUBD        = $02;      {32 bits}

     {The subregister that specifies the entire register.}
                  R_SUBWHOLE    = R_SUBD;  {i386}
                  {R_SUBWHOLE    = R_SUBQ;} {Hammer}

      {Number of first and last superregister.}
      first_supreg    = $01;
      last_supreg     = $10;

      first_imreg     = $11;
      last_imreg      = $ff;

      {# First register in the tregister enumeration }
      firstreg = low(Toldregister);
      {# Last register in the tregister enumeration }
      lastreg  = R_FPSR;

    type
      {# Type definition for the array of string of register nnames }
      reg2strtable = array[firstreg..lastreg] of string[7];
      regname2regnumrec = record
        name:string[6];
        number:Tnewregister;
      end;

    const
     std_reg2str : reg2strtable =
      ('', 'd0','d1','d2','d3','d4','d5','d6','d7',
       'a0','a1','a2','a3','a4','a5','a6','sp',
       '-(sp)','(sp)+',
       'ccr','fp0','fp1','fp2','fp3','fp4','fp5',
       'fp6','fp7','fpcr','sr','ssp','dfc',
       'sfc','vbr','fpsr');

{*****************************************************************************
                                Conditions
*****************************************************************************}

{*****************************************************************************
                                Conditions
*****************************************************************************}

    type
      TAsmCond=(C_None,
         C_CC,C_LS,C_CS,C_LT,C_EQ,C_MI,C_F,C_NE,
         C_GE,C_PL,C_GT,C_T,C_HI,C_VC,C_LE,C_VS
      );


    const
      cond2str:array[TAsmCond] of string[3]=('',
        'cc','ls','cs','lt','eq','mi','f','ne',
        'ge','pl','gt','t','hi','vc','le','vs'
      );


{*****************************************************************************
                                   Flags
*****************************************************************************}

    type
      TResFlags = (
          F_E,F_NE,
          F_G,F_L,F_GE,F_LE,F_C,F_NC,F_A,F_AE,F_B,F_BE);

{*****************************************************************************
                                Reference
*****************************************************************************}

    type
      trefoptions=(ref_none,ref_parafixup,ref_localfixup,ref_selffixup);

      { direction of address register :      }
      {              (An)     (An)+   -(An)  }
      tdirection = (dir_none,dir_inc,dir_dec);

      { reference record }
      preference = ^treference;
      treference = packed record
         base,
         index       : tregister;
         scalefactor : byte;
         offset      : longint;
         symbol      : tasmsymbol;
         offsetfixup : longint;
         options     : trefoptions;
         { indexed increment and decrement mode }
         { (An)+ and -(An)                      }
         direction : tdirection;
      end;

      { reference record }
      pparareference = ^tparareference;
      tparareference = packed record
         index       : tregister;
         offset      : longint;
      end;



{*****************************************************************************
                                Operands
*****************************************************************************}

      { Types of operand }
      toptype=(top_none,top_reg,top_ref,top_const,top_symbol,top_reglist);

      tregisterlist = set of Toldregister;

      toper=record
        ot  : longint;
        case typ : toptype of
         top_none   : ();
         top_reg    : (reg:tregister);
         top_ref    : (ref:preference);
         top_const  : (val:aword);
         top_symbol : (sym:tasmsymbol;symofs:longint);
         { used for pushing/popping multiple registers }
         top_reglist : (registerlist:Tsupregset);
      end;

{*****************************************************************************
                               Generic Location
*****************************************************************************}

    type
      { tparamlocation describes where a parameter for a procedure is stored.
        References are given from the caller's point of view. The usual
        TLocation isn't used, because contains a lot of unnessary fields.
      }
      tparalocation = packed record
         size : TCGSize;
         loc  : TCGLoc;
         sp_fixup : longint;
         case TCGLoc of
            LOC_REFERENCE : (reference : tparareference);
            { segment in reference at the same place as in loc_register }
            LOC_REGISTER,LOC_CREGISTER : (
              case longint of
                1 : (register,registerhigh : tregister);
                { overlay a registerlow }
                2 : (registerlow : tregister);
                { overlay a 64 Bit register type }
                3 : (reg64 : tregister64);
                4 : (register64 : tregister64);
              );
      end;

      tlocation = packed record
         loc  : TCGLoc;
         size : TCGSize;
         case TCGLoc of
            LOC_FLAGS : (resflags : tresflags);
            LOC_CONSTANT : (
              case longint of
                1 : (value : AWord);
                { can't do this, this layout depends on the host cpu. Use }
                { lo(valueqword)/hi(valueqword) instead (JM)              }
                { 2 : (valuelow, valuehigh:AWord);                        }
                { overlay a complete 64 Bit value }
                3 : (valueqword : qword);
              );
            LOC_CREFERENCE,
            LOC_REFERENCE : (reference : treference);
            { segment in reference at the same place as in loc_register }
            LOC_REGISTER,LOC_CREGISTER : (
              case longint of
                1 : (register,registerhigh,segment : tregister);
                { overlay a registerlow }
                2 : (registerlow : tregister);
                { overlay a 64 Bit register type }
                3 : (reg64 : tregister64);
                4 : (register64 : tregister64);
              );
      end;


{*****************************************************************************
                                Operand Sizes
*****************************************************************************}

       { S_NO = No Size of operand   }
       { S_B  = 8-bit size operand   }
       { S_W  = 16-bit size operand  }
       { S_L  = 32-bit size operand  }
       { Floating point types        }
       { S_FS  = single type (32 bit) }
       { S_FD  = double/64bit integer }
       { S_FX  = Extended type      }
       topsize = (S_NO,S_B,S_W,S_L,S_FS,S_FD,S_FX,S_IQ);

{*****************************************************************************
                                 Constants
*****************************************************************************}

    const
      {# maximum number of operands in assembler instruction }
      max_operands = 4;

      lvaluelocations = [LOC_REFERENCE,LOC_CFPUREGISTER,LOC_CREGISTER];

      {# Constant defining possibly all registers which might require saving }
      ALL_REGISTERS = [R_D1..R_FPCR];
      ALL_INTREGISTERS = [1..255];

      general_registers = [R_D0..R_D7];
      general_superregisters = [RS_D0..RS_D7];

      {# low and high of the available maximum width integer general purpose }
      { registers                                                            }
      LoGPReg = R_D0;
      HiGPReg = R_D7;

      {# low and high of every possible width general purpose register (same as }
      { above on most architctures apart from the 80x86)                        }
      LoReg = LoGPReg;
      HiReg = HiGPReg;

      { Table of registers which can be allocated by the code generator
         internally, when generating the code.

       legend:
        xxxregs = set of all possibly used registers of that type in the code
                 generator
        usableregsxxx = set of all 32bit components of registers that can be
                 possible allocated to a regvar or using getregisterxxx (this
                 excludes registers which can be only used for parameter
                 passing on ABI's that define this)
       c_countusableregsxxx = amount of registers in the usableregsxxx set    }

      maxintregs = 8;
      intregs    = [R_D0..R_D7];
      usableregsint = [RS_D2..RS_D7];
      c_countusableregsint = 6;

      maxfpuregs = 8;
      fpuregs    = [R_FP0..R_FP7];
      usableregsfpu = [R_FP2..R_FP7];
      c_countusableregsfpu = 6;

      mmregs     = [];
      usableregsmm  = [];
      c_countusableregsmm  = 0;

      maxaddrregs = 8;
      addrregs    = [R_A0..R_SP];
      usableregsaddr = [RS_A2..RS_A4];
      c_countusableregsaddr = 3;


      { The first register in the usableregsint array }
      firstsaveintreg = RS_D2;
      { The last register in the usableregsint array }
      lastsaveintreg  = RS_D7;
      { The first register in the usableregsfpu array }
      firstsavefpureg = R_FP2;
      { The last  register in the usableregsfpu array }
      lastsavefpureg  = R_FP7;

      { these constants are m68k specific              }
      { The first register in the usableregsaddr array }
      firstsaveaddrreg = RS_A2;
      { The last  register in the usableregsaddr array }
      lastsaveaddrreg  = RS_A4;

      firstsavemmreg  = R_NO;
      lastsavemmreg   = R_NO;

      {
       Defines the maxinum number of integer registers which can be used as variable registers
      }
      maxvarregs = 6;
      { Array of integer registers which can be used as variable registers }
      varregs : Array [1..maxvarregs] of Toldregister =
                (R_D2,R_D3,R_D4,R_D5,R_D6,R_D7);

      {
       Defines the maxinum number of float registers which can be used as variable registers
      }
      maxfpuvarregs = 6;
      { Array of float registers which can be used as variable registers }
      fpuvarregs : Array [1..maxfpuvarregs] of Toldregister =
                (R_FP2,R_FP3,R_FP4,R_FP5,R_FP6,R_FP7);

      {
       Defines the number of integer registers which are used in the ABI to pass parameters
       (might be empty on systems which use the stack to pass parameters)
      }
      max_param_regs_int = 0;
      {param_regs_int: Array[1..max_param_regs_int] of tregister =
        (R_3,R_4,R_5,R_6,R_7,R_8,R_9,R_10);}

      {
       Defines the number of float registers which are used in the ABI to pass parameters
       (might be empty on systems which use the stack to pass parameters)
      }
      max_param_regs_fpu = 0;
      {param_regs_fpu: Array[1..max_param_regs_fpu] of tregister =
        (R_F1,R_F2,R_F3,R_F4,R_F5,R_F6,R_F7,R_F8,R_F9,R_F10,R_F11,R_F12,R_F13);}

      {
       Defines the number of mmx registers which are used in the ABI to pass parameters
       (might be empty on systems which use the stack to pass parameters)
      }
      max_param_regs_mm = 0;
      {param_regs_mm: Array[1..max_param_regs_mm] of tregister =
        (R_M1,R_M2,R_M3,R_M4,R_M5,R_M6,R_M7,R_M8,R_M9,R_M10,R_M11,R_M12,R_M13);}

      {# Registers which are defined as scratch integer and no need to save across
         routine calls or in assembler blocks.
      }
      max_scratch_regs = 4;
      scratch_regs: Array[1..max_scratch_regs] of Tsuperregister = (RS_D0,RS_D1,RS_A0,RS_A1);

{*****************************************************************************
                          Default generic sizes
*****************************************************************************}

      {# Defines the default address size for a processor, }
      OS_ADDR = OS_32;
      {# the natural int size for a processor,             }
      OS_INT = OS_32;
      {# the maximum float size for a processor,           }
      OS_FLOAT = OS_F64;
      {# the size of a vector register for a processor     }
      OS_VECTOR = OS_M128;


{*****************************************************************************
                               GDB Information
*****************************************************************************}

      {# Register indexes for stabs information, when some
         parameters or variables are stored in registers.

         Taken from m68kelf.h (DBX_REGISTER_NUMBER)
         from GCC 3.x source code.

         This is not compatible with the m68k-sun
         implementation.
      }
          stab_regindex : array[firstreg..lastreg] of shortint =
        (-1,                 { R_NO }
          0,1,2,3,4,5,6,7,   { R_D0..R_D7 }
          8,9,10,11,12,13,14,15,  { R_A0..R_A7 }
          -1,-1,-1,                { R_SPPUSH, R_SPPULL, R_CCR }
          18,19,20,21,22,23,24,25, { R_FP0..R_FP7    }
          -1,-1,-1,-1,-1,-1,-1);

{*****************************************************************************
                          Generic Register names
*****************************************************************************}

      {# Stack pointer register }
      stack_pointer_reg = R_SP;
      NR_STACK_POINTER_REG = NR_A7;
      RS_STACK_POINTER_REG = RS_A7;
      {# Frame pointer register }
      frame_pointer_reg = R_A6;
      NR_FRAME_POINTER_REG = NR_A6;
      RS_FRAME_POINTER_REG = RS_A6;
      {# Self pointer register : contains the instance address of an
         object or class. }
      self_pointer_reg  = R_A5;
      NR_SELF_POINTER_REG = NR_A5;
      RS_SELF_POINTER_REG = RS_A5;
      {# Register for addressing absolute data in a position independant way,
         such as in PIC code. The exact meaning is ABI specific. For
         further information look at GCC source : PIC_OFFSET_TABLE_REGNUM
      }
      pic_offset_reg = R_A5;
      {# Results are returned in this register (32-bit values) }
      accumulator   = R_D0;
      NR_ACCUMULATOR = NR_D0;
      RS_ACCUMULATOR = RS_D0;
  {the return_result_reg, is used inside the called function to store its return
  value when that is a scalar value otherwise a pointer to the address of the
  result is placed inside it}
  return_result_reg   = accumulator;
  NR_RETURN_RESULT_REG = NR_ACCUMULATOR;
  RS_RETURN_RESULT_REG = RS_ACCUMULATOR;

  {the function_result_reg contains the function result after a call to a scalar
  function othewise it contains a pointer to the returned result}
  function_result_reg = accumulator;
      {# Hi-Results are returned in this register (64-bit value high register) }
      accumulatorhigh = R_D1;
      NR_ACCUMULATORHIGH = NR_D1;
      RS_ACCUMULATORHIGH = RS_D1;
      {# Floating point results will be placed into this register }
      FPU_RESULT_REG = R_FP0;
      mmresultreg = R_NO;

{*****************************************************************************
                       GCC /ABI linking information
*****************************************************************************}

      {# Registers which must be saved when calling a routine declared as
         cppdecl, cdecl, stdcall, safecall, palmossyscall. The registers
         saved should be the ones as defined in the target ABI and / or GCC.

         This value can be deduced from CALLED_USED_REGISTERS array in the
         GCC source.
      }
      std_saved_registers = [RS_D2..RS_D7,RS_A2..RS_A5];
      {# Required parameter alignment when calling a routine declared as
         stdcall and cdecl. The alignment value should be the one defined
         by GCC or the target ABI.

         The value of this constant is equal to the constant
         PARM_BOUNDARY / BITS_PER_UNIT in the GCC source.
      }
      std_param_align = 4;  { for 32-bit version only }

{*****************************************************************************
                            CPU Dependent Constants
*****************************************************************************}


{*****************************************************************************
                                  Helpers
*****************************************************************************}

    function  is_calljmp(o:tasmop):boolean;

    procedure inverse_flags(var r : TResFlags);
    function  flags_to_cond(const f: TResFlags) : TAsmCond;
    procedure convert_register_to_enum(var r:Tregister);
    function cgsize2subreg(s:Tcgsize):Tsubregister;
    function supreg_name(r:Tsuperregister):string;

implementation

    uses
      verbose;

{*****************************************************************************
                                  Helpers
*****************************************************************************}

    function is_calljmp(o:tasmop):boolean;
      begin
        is_calljmp := false;
        if o in [A_BXX,A_FBXX,A_DBXX,A_BCC..A_BVS,A_DBCC..A_DBVS,A_FBEQ..A_FSNGLE,
          A_JSR,A_BSR,A_JMP] then
           is_calljmp := true;
      end;

    procedure inverse_flags(var r: TResFlags);
      const flagsinvers : array[F_E..F_BE] of tresflags =
            (F_NE,F_E,
             F_LE,F_GE,
             F_L,F_G,
             F_NC,F_C,
             F_BE,F_B,
             F_AE,F_A);
      begin
         r:=flagsinvers[r];
      end;



    function flags_to_cond(const f: TResFlags) : TAsmCond;
      const flags2cond: array[tresflags] of tasmcond = (
          C_EQ,{F_E     equal}
          C_NE,{F_NE    not equal}
          C_GT,{F_G     gt signed}
          C_LT,{F_L     lt signed}
          C_GE,{F_GE    ge signed}
          C_LE,{F_LE    le signed}
          C_CS,{F_C     carry set}
          C_CC,{F_NC    carry clear}
          C_HI,{F_A     gt unsigned}
          C_CC,{F_AE    ge unsigned}
          C_CS,{F_B     lt unsigned}
          C_LS);{F_BE    le unsigned}
      begin
        flags_to_cond := flags2cond[f];
      end;

    procedure convert_register_to_enum(var r:Tregister);

    begin
      if r.enum = R_INTREGISTER then
        case r.number of
          NR_NO: r.enum:= R_NO;
          NR_D0: r.enum:= R_D0;
          NR_D1: r.enum:= R_D1;
          NR_D2: r.enum:= R_D2;
          NR_D3: r.enum:= R_D3;
          NR_D4: r.enum:= R_D4;
          NR_D5: r.enum:= R_D5;
          NR_D6: r.enum:= R_D6;
          NR_D7: r.enum:= R_D7;
          NR_A0: r.enum:= R_A0;
          NR_A1: r.enum:= R_A1;
          NR_A2: r.enum:= R_A2;
          NR_A3: r.enum:= R_A3;
          NR_A4: r.enum:= R_A4;
          NR_A5: r.enum:= R_A5;
          NR_A6: r.enum:= R_A6;
          NR_A7: r.enum:= R_SP;
        else
          internalerror(200301082);
        end;
    end;

    function cgsize2subreg(s:Tcgsize):Tsubregister;

    begin
      case s of
        OS_8,OS_S8:
          cgsize2subreg:=R_SUBL;
        OS_16,OS_S16:
          cgsize2subreg:=R_SUBW;
        OS_32,OS_S32:
          cgsize2subreg:=R_SUBD;
        else
          internalerror(200301231);
      end;
    end;

    function supreg_name(r:Tsuperregister):string;

    var s:string[4];

    const supreg_names:array[0..last_supreg] of string[4]=
          ('INV',
           'd0','d1','d2','d3','d4','d5','d6','d7',
           'a0','a1','a2','a3','a4','a5','a6','sp');

    begin
      if r in [0..last_supreg] then
        supreg_name:=supreg_names[r]
      else
        begin
          str(r,s);
          supreg_name:='reg'+s;
        end;
    end;

end.
{
  $Log$
  Revision 1.20  2003-04-23 13:40:33  peter
    * fix m68k compile

  Revision 1.19  2003/04/23 12:35:35  florian
    * fixed several issues with powerpc
    + applied a patch from Jonas for nested function calls (PowerPC only)
    * ...

  Revision 1.18  2003/02/19 22:00:16  daniel
    * Code generator converted to new register notation
    - Horribily outdated todo.txt removed

  Revision 1.17  2003/02/02 19:25:54  carl
    * Several bugfixes for m68k target (register alloc., opcode emission)
    + VIS target
    + Generic add more complete (still not verified)

  Revision 1.16  2003/01/09 15:49:56  daniel
    * Added register conversion

  Revision 1.15  2003/01/08 18:43:57  daniel
   * Tregister changed into a record

  Revision 1.14  2002/11/30 23:33:03  carl
    * merges from Pierre's fixes in m68k fixes branch

  Revision 1.13  2002/11/17 18:26:16  mazen
  * fixed a compilation bug accmulator-->accumulator, in definition of return_result_reg

  Revision 1.12  2002/11/17 17:49:09  mazen
  + return_result_reg and function_result_reg are now used, in all plateforms, to pass functions result between called function and its caller. See the explanation of each one

  Revision 1.11  2002/10/14 16:32:36  carl
    + flag_2_cond implemented

  Revision 1.10  2002/08/18 09:02:12  florian
    * fixed compilation problems

  Revision 1.9  2002/08/15 08:13:54  carl
    - a_load_sym_ofs_reg removed
    * loadvmt now calls loadaddr_ref_reg instead

  Revision 1.8  2002/08/14 18:41:47  jonas
    - remove valuelow/valuehigh fields from tlocation, because they depend
      on the endianess of the host operating system -> difficult to get
      right. Use lo/hi(location.valueqword) instead (remember to use
      valueqword and not value!!)

  Revision 1.7  2002/08/13 21:40:58  florian
    * more fixes for ppc calling conventions

  Revision 1.6  2002/08/13 18:58:54  carl
    + m68k problems with cvs fixed?()!

  Revision 1.4  2002/08/12 15:08:44  carl
    + stab register indexes for powerpc (moved from gdb to cpubase)
    + tprocessor enumeration moved to cpuinfo
    + linker in target_info is now a class
    * many many updates for m68k (will soon start to compile)
    - removed some ifdef or correct them for correct cpu

  Revision 1.3  2002/07/29 17:51:32  carl
    + restart m68k support
}