fpc/compiler/ncon.pas

{
    $Id$
    Copyright (c) 2000-2002 by Florian Klaempfl

    Type checking and register allocation for constants

    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 ncon;

{$i fpcdefs.inc}

interface

    uses
      globtype,widestr,
      node,
      aasmbase,aasmtai,cpuinfo,globals,
      symconst,symppu,symtype,symdef,symsym;

    type
       trealconstnode = class(tnode)
          restype : ttype;
          value_real : bestreal;
          lab_real : tasmlabel;
          constructor create(v : bestreal;const t:ttype);virtual;
          constructor ppuload(t:tnodetype;ppufile:tcompilerppufile);override;
          procedure ppuwrite(ppufile:tcompilerppufile);override;
          procedure buildderefimpl;override;
          procedure derefimpl;override;
          function getcopy : tnode;override;
          function pass_1 : tnode;override;
          function det_resulttype:tnode;override;
          function docompare(p: tnode) : boolean; override;
          procedure printnodedata(var t:text);override;
       end;
       trealconstnodeclass = class of trealconstnode;

       tordconstnode = class(tnode)
          restype : ttype;
          value : TConstExprInt;
          rangecheck : boolean;
          { create an ordinal constant node of the specified type and value.
            _rangecheck determines if the value of the ordinal should be checked
            against the ranges of the type definition.
          }
          constructor create(v : tconstexprint;const t:ttype; _rangecheck : boolean);virtual;
          constructor ppuload(t:tnodetype;ppufile:tcompilerppufile);override;
          procedure ppuwrite(ppufile:tcompilerppufile);override;
          procedure buildderefimpl;override;
          procedure derefimpl;override;
          function getcopy : tnode;override;
          function pass_1 : tnode;override;
          function det_resulttype:tnode;override;
          function docompare(p: tnode) : boolean; override;
          procedure printnodedata(var t:text);override;
       end;
       tordconstnodeclass = class of tordconstnode;

       tpointerconstnode = class(tnode)
          restype : ttype;
          value   : TConstPtrUInt;
          constructor create(v : TConstPtrUInt;const t:ttype);virtual;
          constructor ppuload(t:tnodetype;ppufile:tcompilerppufile);override;
          procedure ppuwrite(ppufile:tcompilerppufile);override;
          procedure buildderefimpl;override;
          procedure derefimpl;override;
          function getcopy : tnode;override;
          function pass_1 : tnode;override;
          function det_resulttype:tnode;override;
          function docompare(p: tnode) : boolean; override;
       end;
       tpointerconstnodeclass = class of tpointerconstnode;

       tstringconstnode = class(tnode)
          value_str : pchar;
          len : longint;
          lab_str : tasmlabel;
          st_type : tstringtype;
          constructor createstr(const s : string;st:tstringtype);virtual;
          constructor createpchar(s : pchar;l : longint);virtual;
          constructor createwstr(w : pcompilerwidestring);virtual;
          constructor ppuload(t:tnodetype;ppufile:tcompilerppufile);override;
          procedure ppuwrite(ppufile:tcompilerppufile);override;
          procedure buildderefimpl;override;
          procedure derefimpl;override;
          destructor destroy;override;
          function getcopy : tnode;override;
          function pass_1 : tnode;override;
          function det_resulttype:tnode;override;
          function getpcharcopy : pchar;
          function docompare(p: tnode) : boolean; override;
       end;
       tstringconstnodeclass = class of tstringconstnode;

       tsetconstnode = class(tunarynode)
          restype : ttype;
          value_set : pconstset;
          lab_set : tasmlabel;
          constructor create(s : pconstset;const t:ttype);virtual;
          destructor destroy;override;
          constructor ppuload(t:tnodetype;ppufile:tcompilerppufile);override;
          procedure ppuwrite(ppufile:tcompilerppufile);override;
          procedure buildderefimpl;override;
          procedure derefimpl;override;
          function getcopy : tnode;override;
          function pass_1 : tnode;override;
          function det_resulttype:tnode;override;
          function docompare(p: tnode) : boolean; override;
       end;
       tsetconstnodeclass = class of tsetconstnode;

       tnilnode = class(tnode)
          constructor create;virtual;
          function pass_1 : tnode;override;
          function det_resulttype:tnode;override;
       end;
       tnilnodeclass = class of tnilnode;

       tguidconstnode = class(tnode)
          value : tguid;
          constructor create(const g:tguid);virtual;
          constructor ppuload(t:tnodetype;ppufile:tcompilerppufile);override;
          procedure ppuwrite(ppufile:tcompilerppufile);override;
          function getcopy : tnode;override;
          function pass_1 : tnode;override;
          function det_resulttype:tnode;override;
          function docompare(p: tnode) : boolean; override;
       end;
       tguidconstnodeclass = class of tguidconstnode;

    var
       crealconstnode : trealconstnodeclass;
       cordconstnode : tordconstnodeclass;
       cpointerconstnode : tpointerconstnodeclass;
       cstringconstnode : tstringconstnodeclass;
       csetconstnode : tsetconstnodeclass;
       cguidconstnode : tguidconstnodeclass;
       cnilnode : tnilnodeclass;

    function genintconstnode(v : TConstExprInt) : tordconstnode;
    function genenumnode(v : tenumsym) : tordconstnode;

    { some helper routines }
{$ifdef INT64FUNCRESOK}
    function get_ordinal_value(p : tnode) : TConstExprInt;
{$else INT64FUNCRESOK}
    function get_ordinal_value(p : tnode) : longint;
{$endif INT64FUNCRESOK}
    function is_constnode(p : tnode) : boolean;
    function is_constintnode(p : tnode) : boolean;
    function is_constcharnode(p : tnode) : boolean;
    function is_constrealnode(p : tnode) : boolean;
    function is_constboolnode(p : tnode) : boolean;
    function is_constenumnode(p : tnode) : boolean;
    function is_constresourcestringnode(p : tnode) : boolean;
    function is_constwidecharnode(p : tnode) : boolean;
    function str_length(p : tnode) : longint;
    function is_emptyset(p : tnode):boolean;
    function genconstsymtree(p : tconstsym) : tnode;

implementation

    uses
      cutils,
      verbose,systems,
      defutil,
      cpubase,cgbase,
      nld;

    function genintconstnode(v : TConstExprInt) : tordconstnode;

      var
         i,i2 : TConstExprInt;

      begin
         { we need to bootstrap this code, so it's a little bit messy }
         i:=2147483647;
         { maxcardinal }
         i2 := i+i+1;
         if (v<=i) and (v>=-i-1) then
           genintconstnode:=cordconstnode.create(v,s32bittype,true)
         else if (v > i) and (v <= i2) then
           genintconstnode:=cordconstnode.create(v,u32bittype,true)
         else
           genintconstnode:=cordconstnode.create(v,cs64bittype,true);
      end;


    function genenumnode(v : tenumsym) : tordconstnode;
      var
        htype : ttype;
      begin
         htype.setdef(v.definition);
         genenumnode:=cordconstnode.create(v.value,htype,true);
      end;


{$ifdef INT64FUNCRESOK}
    function get_ordinal_value(p : tnode) : TConstExprInt;
{$else INT64FUNCRESOK}
    function get_ordinal_value(p : tnode) : longint;
{$endif INT64FUNCRESOK}
      begin
        get_ordinal_value:=0;
        if is_constnode(p) then
          begin
            if p.nodetype=ordconstn then
              get_ordinal_value:=tordconstnode(p).value
            else
              Message(type_e_ordinal_expr_expected);
          end
        else
          Message(type_e_constant_expr_expected);
      end;


    function is_constnode(p : tnode) : boolean;
      begin
        is_constnode:=(p.nodetype in [niln,ordconstn,realconstn,stringconstn,setconstn,guidconstn]);
      end;


    function is_constintnode(p : tnode) : boolean;
      begin
         is_constintnode:=(p.nodetype=ordconstn) and is_integer(p.resulttype.def);
      end;


    function is_constcharnode(p : tnode) : boolean;

      begin
         is_constcharnode:=(p.nodetype=ordconstn) and is_char(p.resulttype.def);
      end;


    function is_constwidecharnode(p : tnode) : boolean;

      begin
         is_constwidecharnode:=(p.nodetype=ordconstn) and is_widechar(p.resulttype.def);
      end;


    function is_constrealnode(p : tnode) : boolean;

      begin
         is_constrealnode:=(p.nodetype=realconstn);
      end;


    function is_constboolnode(p : tnode) : boolean;

      begin
         is_constboolnode:=(p.nodetype=ordconstn) and is_boolean(p.resulttype.def);
      end;


    function is_constenumnode(p : tnode) : boolean;

      begin
         is_constenumnode:=(p.nodetype=ordconstn) and (p.resulttype.def.deftype=enumdef);
      end;


    function is_constresourcestringnode(p : tnode) : boolean;
      begin
        is_constresourcestringnode:=(p.nodetype=loadn) and
          (tloadnode(p).symtableentry.typ=constsym) and
          (tconstsym(tloadnode(p).symtableentry).consttyp=constresourcestring);
      end;


    function str_length(p : tnode) : longint;

      begin
         str_length:=tstringconstnode(p).len;
      end;

    function is_emptyset(p : tnode):boolean;
      begin
        is_emptyset:=(p.nodetype=setconstn) and
                     (Tsetconstnode(p).value_set^=[]);
      end;


    function genconstsymtree(p : tconstsym) : tnode;
      var
        p1  : tnode;
        len : longint;
        pc  : pchar;
      begin
        p1:=nil;
        case p.consttyp of
          constint :
            p1:=genintconstnode(p.value.valueord);
          conststring :
            begin
              len:=p.value.len;
              if not(cs_ansistrings in aktlocalswitches) and (len>255) then
               len:=255;
              getmem(pc,len+1);
              move(pchar(p.value.valueptr)^,pc^,len);
              pc[len]:=#0;
              p1:=cstringconstnode.createpchar(pc,len);
            end;
          constchar :
            p1:=cordconstnode.create(p.value.valueord,cchartype,true);
          constreal :
            p1:=crealconstnode.create(pbestreal(p.value.valueptr)^,pbestrealtype^);
          constbool :
            p1:=cordconstnode.create(p.value.valueord,booltype,true);
          constset :
            p1:=csetconstnode.create(pconstset(p.value.valueptr),p.consttype);
          constord :
            p1:=cordconstnode.create(p.value.valueord,p.consttype,true);
          constpointer :
            p1:=cpointerconstnode.create(p.value.valueordptr,p.consttype);
          constnil :
            p1:=cnilnode.create;
          else
            internalerror(200205103);
        end;
        genconstsymtree:=p1;
      end;

{*****************************************************************************
                             TREALCONSTNODE
*****************************************************************************}

    { generic code     }
    { overridden by:   }
    {   i386           }
    constructor trealconstnode.create(v : bestreal;const t:ttype);
      begin
         inherited create(realconstn);
         restype:=t;
         value_real:=v;
         lab_real:=nil;
      end;

    constructor trealconstnode.ppuload(t:tnodetype;ppufile:tcompilerppufile);
      begin
        inherited ppuload(t,ppufile);
        ppufile.gettype(restype);
        value_real:=ppufile.getreal;
        lab_real:=tasmlabel(ppufile.getasmsymbol);
      end;


    procedure trealconstnode.ppuwrite(ppufile:tcompilerppufile);
      begin
        inherited ppuwrite(ppufile);
        ppufile.puttype(restype);
        ppufile.putreal(value_real);
        ppufile.putasmsymbol(lab_real);
      end;


    procedure trealconstnode.buildderefimpl;
      begin
        inherited buildderefimpl;
        restype.buildderef;
      end;


    procedure trealconstnode.derefimpl;
      begin
        inherited derefimpl;
        restype.resolve;
        objectlibrary.derefasmsymbol(tasmsymbol(lab_real));
      end;


    function trealconstnode.getcopy : tnode;

      var
         n : trealconstnode;

      begin
         n:=trealconstnode(inherited getcopy);
         n.value_real:=value_real;
         n.lab_real:=lab_real;
         getcopy:=n;
      end;

    function trealconstnode.det_resulttype:tnode;
      begin
        result:=nil;
        resulttype:=restype;
      end;

    function trealconstnode.pass_1 : tnode;
      begin
         result:=nil;
         expectloc:=LOC_CREFERENCE;
         { needs to be loaded into an FPU register }
         registersfpu:=1;
      end;

    function trealconstnode.docompare(p: tnode): boolean;
      begin
        docompare :=
          inherited docompare(p) and
          (value_real = trealconstnode(p).value_real) and
          { floating point compares for non-numbers give strange results usually }
          is_number_float(value_real) and
          is_number_float(trealconstnode(p).value_real);
      end;


    procedure Trealconstnode.printnodedata(var t:text);
      begin
        inherited printnodedata(t);
        writeln(t,printnodeindention,'value = ',value_real);
      end;


{*****************************************************************************
                              TORDCONSTNODE
*****************************************************************************}

    constructor tordconstnode.create(v : tconstexprint;const t:ttype;_rangecheck : boolean);

      begin
         inherited create(ordconstn);
         value:=v;
         restype:=t;
         rangecheck := _rangecheck;
      end;


    constructor tordconstnode.ppuload(t:tnodetype;ppufile:tcompilerppufile);
      begin
        inherited ppuload(t,ppufile);
        ppufile.gettype(restype);
        value:=ppufile.getexprint;
        { normally, the value is already compiled, so we don't need
          to do once again a range check
        }
        rangecheck := false;
      end;


    procedure tordconstnode.ppuwrite(ppufile:tcompilerppufile);
      begin
        inherited ppuwrite(ppufile);
        ppufile.puttype(restype);
        ppufile.putexprint(value);
      end;


    procedure tordconstnode.buildderefimpl;
      begin
        inherited buildderefimpl;
        restype.buildderef;
      end;


    procedure tordconstnode.derefimpl;
      begin
        inherited derefimpl;
        restype.resolve;
      end;


    function tordconstnode.getcopy : tnode;

      var
         n : tordconstnode;

      begin
         n:=tordconstnode(inherited getcopy);
         n.value:=value;
         n.restype := restype;
         getcopy:=n;
      end;

    function tordconstnode.det_resulttype:tnode;
      begin
        result:=nil;
        resulttype:=restype;
        { only do range checking when explicitly asked for it }
        if rangecheck then
           testrange(resulttype.def,value,false);
      end;

    function tordconstnode.pass_1 : tnode;
      begin
         result:=nil;
         expectloc:=LOC_CONSTANT;
      end;

    function tordconstnode.docompare(p: tnode): boolean;
      begin
        docompare :=
          inherited docompare(p) and
          (value = tordconstnode(p).value);
      end;


    procedure Tordconstnode.printnodedata(var t:text);
      begin
        inherited printnodedata(t);
        writeln(t,printnodeindention,'value = ',value);
      end;


{*****************************************************************************
                            TPOINTERCONSTNODE
*****************************************************************************}

    constructor tpointerconstnode.create(v : TConstPtrUInt;const t:ttype);

      begin
         inherited create(pointerconstn);
         value:=v;
         restype:=t;
      end;


    constructor tpointerconstnode.ppuload(t:tnodetype;ppufile:tcompilerppufile);
      begin
        inherited ppuload(t,ppufile);
        ppufile.gettype(restype);
        value:=ppufile.getptruint;
      end;


    procedure tpointerconstnode.ppuwrite(ppufile:tcompilerppufile);
      begin
        inherited ppuwrite(ppufile);
        ppufile.puttype(restype);
        ppufile.putptruint(value);
      end;


    procedure tpointerconstnode.buildderefimpl;
      begin
        inherited buildderefimpl;
        restype.buildderef;
      end;


    procedure tpointerconstnode.derefimpl;
      begin
        inherited derefimpl;
        restype.resolve;
      end;


    function tpointerconstnode.getcopy : tnode;

      var
         n : tpointerconstnode;

      begin
         n:=tpointerconstnode(inherited getcopy);
         n.value:=value;
         n.restype := restype;
         getcopy:=n;
      end;

    function tpointerconstnode.det_resulttype:tnode;
      begin
        result:=nil;
        resulttype:=restype;
      end;

    function tpointerconstnode.pass_1 : tnode;
      begin
         result:=nil;
         expectloc:=LOC_CONSTANT;
      end;

    function tpointerconstnode.docompare(p: tnode): boolean;
      begin
        docompare :=
          inherited docompare(p) and
          (value = tpointerconstnode(p).value);
      end;


{*****************************************************************************
                             TSTRINGCONSTNODE
*****************************************************************************}

    constructor tstringconstnode.createstr(const s : string;st:tstringtype);

      var
         l : longint;

      begin
         inherited create(stringconstn);
         l:=length(s);
         len:=l;
         { stringdup write even past a #0 }
         getmem(value_str,l+1);
         move(s[1],value_str^,l);
         value_str[l]:=#0;
         lab_str:=nil;
         if st=st_default then
          begin
            if cs_ansistrings in aktlocalswitches then
              st_type:=st_ansistring
            else
              st_type:=st_shortstring;
          end
         else
          st_type:=st;
      end;

    constructor tstringconstnode.createwstr(w : pcompilerwidestring);

      begin
         inherited create(stringconstn);
         len:=getlengthwidestring(w);
         initwidestring(pcompilerwidestring(value_str));
         copywidestring(w,pcompilerwidestring(value_str));
         lab_str:=nil;
         st_type:=st_widestring;
      end;

    constructor tstringconstnode.createpchar(s : pchar;l : longint);

      begin
         inherited create(stringconstn);
         len:=l;
         value_str:=s;
         if (cs_ansistrings in aktlocalswitches) or
            (len>255) then
          st_type:=st_ansistring
         else
          st_type:=st_shortstring;
         lab_str:=nil;
      end;


    destructor tstringconstnode.destroy;
      begin
        if st_type=st_widestring then
         donewidestring(pcompilerwidestring(value_str))
        else
         ansistringdispose(value_str,len);
        inherited destroy;
      end;


    constructor tstringconstnode.ppuload(t:tnodetype;ppufile:tcompilerppufile);
      begin
        inherited ppuload(t,ppufile);
        st_type:=tstringtype(ppufile.getbyte);
        len:=ppufile.getlongint;
        getmem(value_str,len+1);
        ppufile.getdata(value_str^,len);
        value_str[len]:=#0;
        lab_str:=tasmlabel(ppufile.getasmsymbol);
      end;


    procedure tstringconstnode.ppuwrite(ppufile:tcompilerppufile);
      begin
        inherited ppuwrite(ppufile);
        ppufile.putbyte(byte(st_type));
        ppufile.putlongint(len);
        ppufile.putdata(value_str^,len);
        ppufile.putasmsymbol(lab_str);
      end;


    procedure tstringconstnode.buildderefimpl;
      begin
        inherited buildderefimpl;
      end;


    procedure tstringconstnode.derefimpl;
      begin
        inherited derefimpl;
        objectlibrary.derefasmsymbol(tasmsymbol(lab_str));
      end;


    function tstringconstnode.getcopy : tnode;

      var
         n : tstringconstnode;

      begin
         n:=tstringconstnode(inherited getcopy);
         n.st_type:=st_type;
         n.len:=len;
         n.lab_str:=lab_str;
         if st_type=st_widestring then
           begin
             initwidestring(pcompilerwidestring(n.value_str));
             copywidestring(pcompilerwidestring(value_str),pcompilerwidestring(n.value_str));
           end
         else
           n.value_str:=getpcharcopy;
         getcopy:=n;
      end;

    function tstringconstnode.det_resulttype:tnode;
      begin
        result:=nil;
        case st_type of
          st_shortstring :
            resulttype:=cshortstringtype;
          st_ansistring :
            resulttype:=cansistringtype;
          st_widestring :
            resulttype:=cwidestringtype;
          st_longstring :
            resulttype:=clongstringtype;
        end;
      end;

    function tstringconstnode.pass_1 : tnode;
      begin
        result:=nil;
        if (st_type in [st_ansistring,st_widestring]) and
           (len=0) then
         expectloc:=LOC_CONSTANT
        else
         expectloc:=LOC_CREFERENCE;
      end;

    function tstringconstnode.getpcharcopy : pchar;
      var
         pc : pchar;
      begin
         pc:=nil;
         getmem(pc,len+1);
         if pc=nil then
           Message(general_f_no_memory_left);
         move(value_str^,pc^,len+1);
         getpcharcopy:=pc;
      end;

    function tstringconstnode.docompare(p: tnode): boolean;
      begin
        docompare :=
          inherited docompare(p) and
          (len = tstringconstnode(p).len) and
          { Don't compare the pchars, since they may contain null chars }
          { Since all equal constant strings are replaced by the same   }
          { label, the following compare should be enough (JM)          }
          (lab_str = tstringconstnode(p).lab_str);
      end;

{*****************************************************************************
                             TSETCONSTNODE
*****************************************************************************}

    constructor tsetconstnode.create(s : pconstset;const t:ttype);

      begin
         inherited create(setconstn,nil);
         restype:=t;
         if assigned(s) then
           begin
              new(value_set);
              value_set^:=s^;
           end
         else
           value_set:=nil;
      end;

    destructor tsetconstnode.destroy;
      begin
        if assigned(value_set) then
         dispose(value_set);
        inherited destroy;
      end;


    constructor tsetconstnode.ppuload(t:tnodetype;ppufile:tcompilerppufile);
      begin
        inherited ppuload(t,ppufile);
        ppufile.gettype(restype);
        new(value_set);
        ppufile.getdata(value_set^,sizeof(tconstset));
      end;


    procedure tsetconstnode.ppuwrite(ppufile:tcompilerppufile);
      begin
        inherited ppuwrite(ppufile);
        ppufile.puttype(restype);
        ppufile.putdata(value_set^,sizeof(tconstset));
      end;


    procedure tsetconstnode.buildderefimpl;
      begin
        inherited buildderefimpl;
        restype.buildderef;
      end;


    procedure tsetconstnode.derefimpl;
      begin
        inherited derefimpl;
        restype.resolve;
      end;


    function tsetconstnode.getcopy : tnode;

      var
         n : tsetconstnode;

      begin
         n:=tsetconstnode(inherited getcopy);
         if assigned(value_set) then
           begin
              new(n.value_set);
              n.value_set^:=value_set^
           end
         else
           n.value_set:=nil;
         n.restype := restype;
         n.lab_set:=lab_set;
         getcopy:=n;
      end;

    function tsetconstnode.det_resulttype:tnode;
      begin
        result:=nil;
        resulttype:=restype;
      end;

    function tsetconstnode.pass_1 : tnode;
      begin
         result:=nil;
         if tsetdef(resulttype.def).settype=smallset then
          expectloc:=LOC_CONSTANT
         else
          expectloc:=LOC_CREFERENCE;
      end;


    function tsetconstnode.docompare(p: tnode): boolean;
      begin
        docompare:=(inherited docompare(p)) and
                   (value_set^=Tsetconstnode(p).value_set^);
      end;


{*****************************************************************************
                               TNILNODE
*****************************************************************************}

    constructor tnilnode.create;

      begin
        inherited create(niln);
      end;

    function tnilnode.det_resulttype:tnode;
      begin
        result:=nil;
        resulttype:=voidpointertype;
      end;

    function tnilnode.pass_1 : tnode;
      begin
        result:=nil;
        expectloc:=LOC_CONSTANT;
      end;

{*****************************************************************************
                            TGUIDCONSTNODE
*****************************************************************************}

    constructor tguidconstnode.create(const g:tguid);

      begin
         inherited create(guidconstn);
         value:=g;
      end;

    constructor tguidconstnode.ppuload(t:tnodetype;ppufile:tcompilerppufile);
      begin
        inherited ppuload(t,ppufile);
        ppufile.getguid(value);
      end;


    procedure tguidconstnode.ppuwrite(ppufile:tcompilerppufile);
      begin
        inherited ppuwrite(ppufile);
        ppufile.putguid(value);
      end;


    function tguidconstnode.getcopy : tnode;

      var
         n : tguidconstnode;

      begin
         n:=tguidconstnode(inherited getcopy);
         n.value:=value;
         getcopy:=n;
      end;

    function tguidconstnode.det_resulttype:tnode;
      begin
        result:=nil;
        resulttype.setdef(rec_tguid);
      end;

    function tguidconstnode.pass_1 : tnode;
      begin
         result:=nil;
         expectloc:=LOC_CREFERENCE;
      end;

    function tguidconstnode.docompare(p: tnode): boolean;
      begin
        docompare :=
          inherited docompare(p) and
          (guid2string(value) = guid2string(tguidconstnode(p).value));
      end;


begin
   crealconstnode:=trealconstnode;
   cordconstnode:=tordconstnode;
   cpointerconstnode:=tpointerconstnode;
   cstringconstnode:=tstringconstnode;
   csetconstnode:=tsetconstnode;
   cnilnode:=tnilnode;
   cguidconstnode:=tguidconstnode;
end.
{
  $Log$
  Revision 1.56  2003-10-23 14:44:07  peter
    * splitted buildderef and buildderefimpl to fix interface crc
      calculation

  Revision 1.55  2003/10/22 20:40:00  peter
    * write derefdata in a separate ppu entry

  Revision 1.54  2003/10/07 18:17:44  peter
    * Give message that constant expr is expected when a none constant
      is passed to get_ordinal_value

  Revision 1.53  2003/10/02 21:18:44  peter
    * niln is also a constnode

  Revision 1.52  2003/10/01 20:34:48  peter
    * procinfo unit contains tprocinfo
    * cginfo renamed to cgbase
    * moved cgmessage to verbose
    * fixed ppc and sparc compiles

  Revision 1.51  2003/09/06 16:47:24  florian
    + support of NaN and Inf in the compiler as values of real constants

  Revision 1.50  2003/09/03 15:55:01  peter
    * NEWRA branch merged

  Revision 1.49  2003/04/25 20:59:33  peter
    * removed funcretn,funcretsym, function result is now in varsym
      and aliases for result and function name are added using absolutesym
    * vs_hidden parameter for funcret passed in parameter
    * vs_hidden fixes
    * writenode changed to printnode and released from extdebug
    * -vp option added to generate a tree.log with the nodetree
    * nicer printnode for statements, callnode

  Revision 1.48  2003/04/24 22:29:57  florian
    * fixed a lot of PowerPC related stuff

  Revision 1.47  2003/04/23 20:16:04  peter
    + added currency support based on int64
    + is_64bit for use in cg units instead of is_64bitint
    * removed cgmessage from n386add, replace with internalerrors

  Revision 1.46  2003/04/22 23:50:23  peter
    * firstpass uses expectloc
    * checks if there are differences between the expectloc and
      location.loc from secondpass in EXTDEBUG

  Revision 1.45  2002/11/25 17:43:18  peter
    * splitted defbase in defutil,symutil,defcmp
    * merged isconvertable and is_equal into compare_defs(_ext)
    * made operator search faster by walking the list only once

  Revision 1.44  2002/11/22 22:48:10  carl
  * memory optimization with tconstsym (1.5%)

  Revision 1.43  2002/10/05 12:43:25  carl
    * fixes for Delphi 6 compilation
     (warning : Some features do not work under Delphi)

  Revision 1.42  2002/09/07 15:25:03  peter
    * old logs removed and tabs fixed

  Revision 1.41  2002/09/07 12:16:04  carl
    * second part bug report 1996 fix, testrange in cordconstnode
      only called if option is set (also make parsing a tiny faster)

  Revision 1.40  2002/08/22 11:21:44  florian
    + register32 is now written by tnode.dowrite
    * fixed write of value of tconstnode

  Revision 1.39  2002/08/18 20:06:23  peter
    * inlining is now also allowed in interface
    * renamed write/load to ppuwrite/ppuload
    * tnode storing in ppu
    * nld,ncon,nbas are already updated for storing in ppu

  Revision 1.38  2002/08/17 22:09:45  florian
    * result type handling in tcgcal.pass_2 overhauled
    * better tnode.dowrite
    * some ppc stuff fixed

  Revision 1.37  2002/07/23 12:34:30  daniel
  * Readded old set code. To use it define 'oldset'. Activated by default
    for ppc.

  Revision 1.36  2002/07/22 11:48:04  daniel
  * Sets are now internally sets.

  Revision 1.35  2002/07/20 11:57:54  florian
    * types.pas renamed to defbase.pas because D6 contains a types
      unit so this would conflicts if D6 programms are compiled
    + Willamette/SSE2 instructions to assembler added

  Revision 1.34  2002/07/14 18:00:43  daniel
  + Added the beginning of a state tracker. This will track the values of
    variables through procedures and optimize things away.

  Revision 1.33  2002/07/01 18:46:23  peter
    * internal linker
    * reorganized aasm layer

  Revision 1.32  2002/05/18 13:34:09  peter
    * readded missing revisions

  Revision 1.31  2002/05/16 19:46:37  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 1.29  2002/05/12 16:53:07  peter
    * moved entry and exitcode to ncgutil and cgobj
    * foreach gets extra argument for passing local data to the
      iterator function
    * -CR checks also class typecasts at runtime by changing them
      into as
    * fixed compiler to cycle with the -CR option
    * fixed stabs with elf writer, finally the global variables can
      be watched
    * removed a lot of routines from cga unit and replaced them by
      calls to cgobj
    * u32bit-s32bit updates for and,or,xor nodes. When one element is
      u32bit then the other is typecasted also to u32bit without giving
      a rangecheck warning/error.
    * fixed pascal calling method with reversing also the high tree in
      the parast, detected by tcalcst3 test

  Revision 1.28  2002/04/07 13:25:20  carl
  + change unit use

  Revision 1.27  2002/04/04 19:05:58  peter
    * removed unused units
    * use tlocation.size in cg.a_*loc*() routines

  Revision 1.26  2002/04/02 17:11:29  peter
    * tlocation,treference update
    * LOC_CONSTANT added for better constant handling
    * secondadd splitted in multiple routines
    * location_force_reg added for loading a location to a register
      of a specified size
    * secondassignment parses now first the right and then the left node
      (this is compatible with Kylix). This saves a lot of push/pop especially
      with string operations
    * adapted some routines to use the new cg methods

  Revision 1.25  2002/03/04 19:10:11  peter
    * removed compiler warnings

}