fpc/compiler/i386/n386util.pas
florian 9746f4c2d6 * some cg reorganisation
* some PPC updates
2001-08-26 13:35:06 +00:00

1608 lines
64 KiB
ObjectPascal

{
$Id$
Copyright (c) 1998-2000 by Florian Klaempfl
Helper routines for the i386 code generator
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 n386util;
{$i defines.inc}
interface
uses
symtype,node;
function maybe_push(needed : byte;p : tnode;isint64 : boolean) : boolean;
{$ifdef TEMPS_NOT_PUSH}
function maybe_savetotemp(needed : byte;p : tnode;isint64 : boolean) : boolean;
{$endif TEMPS_NOT_PUSH}
procedure restore(p : tnode;isint64 : boolean);
{$ifdef TEMPS_NOT_PUSH}
procedure restorefromtemp(p : tnode;isint64 : boolean);
{$endif TEMPS_NOT_PUSH}
procedure pushsetelement(p : tnode);
procedure push_value_para(p:tnode;inlined,is_cdecl:boolean;
para_offset:longint;alignment : longint);
procedure loadshortstring(source,dest : tnode);
procedure loadlongstring(p:tbinarynode);
procedure loadansi2short(source,dest : tnode);
procedure loadwide2short(source,dest : tnode);
procedure loadinterfacecom(p: tbinarynode);
procedure maketojumpbool(p : tnode);
procedure emitoverflowcheck(p:tnode);
procedure emitrangecheck(p:tnode;todef:tdef);
procedure firstcomplex(p : tbinarynode);
implementation
uses
globtype,globals,systems,verbose,
cutils,
aasm,cpubase,cpuasm,
symconst,symbase,symdef,symsym,symtable,
{$ifdef GDB}
gdb,
{$endif GDB}
types,
ncon,nld,
pass_1,pass_2,
cgbase,tgcpu,temp_gen,
cga,regvars;
{*****************************************************************************
Emit Push Functions
*****************************************************************************}
function maybe_push(needed : byte;p : tnode;isint64 : boolean) : boolean;
var
pushed : boolean;
{hregister : tregister; }
{$ifdef TEMPS_NOT_PUSH}
href : treference;
{$endif TEMPS_NOT_PUSH}
begin
if p.location.loc = LOC_CREGISTER then
begin
maybe_push := true;
exit;
end;
if needed>usablereg32 then
begin
if (p.location.loc=LOC_REGISTER) then
begin
if isint64 then
begin
{$ifdef TEMPS_NOT_PUSH}
gettempofsizereference(href,8);
p.temp_offset:=href.offset;
href.offset:=href.offset+4;
exprasmList.concat(Taicpu.Op_reg(A_MOV,S_L,p.location.registerhigh,href));
href.offset:=href.offset-4;
{$else TEMPS_NOT_PUSH}
exprasmList.concat(Taicpu.Op_reg(A_PUSH,S_L,p.location.registerhigh));
{$endif TEMPS_NOT_PUSH}
ungetregister32(p.location.registerhigh);
end
{$ifdef TEMPS_NOT_PUSH}
else
begin
gettempofsizereference(href,4);
p.temp_offset:=href.offset;
end
{$endif TEMPS_NOT_PUSH}
;
pushed:=true;
{$ifdef TEMPS_NOT_PUSH}
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,p.location.register,href));
{$else TEMPS_NOT_PUSH}
exprasmList.concat(Taicpu.Op_reg(A_PUSH,S_L,p.location.register));
{$endif TEMPS_NOT_PUSH}
ungetregister32(p.location.register);
end
else if (p.location.loc in [LOC_MEM,LOC_REFERENCE]) and
((p.location.reference.base<>R_NO) or
(p.location.reference.index<>R_NO)
) then
begin
del_reference(p.location.reference);
getexplicitregister32(R_EDI);
emit_ref_reg(A_LEA,S_L,newreference(p.location.reference),R_EDI);
{$ifdef TEMPS_NOT_PUSH}
gettempofsizereference(href,4);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,href));
p.temp_offset:=href.offset;
{$else TEMPS_NOT_PUSH}
exprasmList.concat(Taicpu.Op_reg(A_PUSH,S_L,R_EDI));
{$endif TEMPS_NOT_PUSH}
ungetregister32(R_EDI);
pushed:=true;
end
else pushed:=false;
end
else pushed:=false;
maybe_push:=pushed;
end;
{$ifdef TEMPS_NOT_PUSH}
function maybe_savetotemp(needed : byte;p : tnode;isint64 : boolean) : boolean;
var
pushed : boolean;
href : treference;
begin
if needed>usablereg32 then
begin
if (p^.location.loc=LOC_REGISTER) then
begin
if isint64(p^.resulttype.def) then
begin
gettempofsizereference(href,8);
p^.temp_offset:=href.offset;
href.offset:=href.offset+4;
exprasmList.concat(Taicpu.Op_reg(A_MOV,S_L,p^.location.registerhigh,href));
href.offset:=href.offset-4;
ungetregister32(p^.location.registerhigh);
end
else
begin
gettempofsizereference(href,4);
p^.temp_offset:=href.offset;
end;
pushed:=true;
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,p^.location.register,href));
ungetregister32(p^.location.register);
end
else if (p^.location.loc in [LOC_MEM,LOC_REFERENCE]) and
((p^.location.reference.base<>R_NO) or
(p^.location.reference.index<>R_NO)
) then
begin
del_reference(p^.location.reference);
getexplicitregister32(R_EDI);
emit_ref_reg(A_LEA,S_L,newreference(p^.location.reference),
R_EDI);
gettempofsizereference(href,4);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,href));
ungetregister32(R_EDI);
p^.temp_offset:=href.offset;
pushed:=true;
end
else pushed:=false;
end
else pushed:=false;
maybe_push:=pushed;
end;
{$endif TEMPS_NOT_PUSH}
procedure restore(p : tnode;isint64 : boolean);
var
hregister : tregister;
{$ifdef TEMPS_NOT_PUSH}
href : treference;
{$endif TEMPS_NOT_PUSH}
begin
if p.location.loc = LOC_CREGISTER then
begin
load_regvar_reg(exprasmlist,p.location.register);
exit;
end;
hregister:=getregister32;
{$ifdef TEMPS_NOT_PUSH}
reset_reference(href);
href.base:=procinfo^.frame_pointer;
href.offset:=p.temp_offset;
emit_ref_reg(A_MOV,S_L,href,hregister);
{$else TEMPS_NOT_PUSH}
exprasmList.concat(Taicpu.Op_reg(A_POP,S_L,hregister));
{$endif TEMPS_NOT_PUSH}
if (p.location.loc in [LOC_REGISTER,LOC_CREGISTER]) then
begin
p.location.register:=hregister;
if isint64 then
begin
p.location.registerhigh:=getregister32;
{$ifdef TEMPS_NOT_PUSH}
href.offset:=p.temp_offset+4;
emit_ref_reg(A_MOV,S_L,p.location.registerhigh);
{ set correctly for release ! }
href.offset:=p.temp_offset;
{$else TEMPS_NOT_PUSH}
exprasmList.concat(Taicpu.Op_reg(A_POP,S_L,p.location.registerhigh));
{$endif TEMPS_NOT_PUSH}
end;
end
else
begin
reset_reference(p.location.reference);
{ any reasons why this was moved into the index register ? }
{ normally usage of base register is much better (FK) }
p.location.reference.base:=hregister;
{ Why is this done? We can never be sure about p.left
because otherwise secondload fails !!!
set_location(p.left^.location,p.location);}
end;
{$ifdef TEMPS_NOT_PUSH}
ungetiftemp(href);
{$endif TEMPS_NOT_PUSH}
end;
{$ifdef TEMPS_NOT_PUSH}
procedure restorefromtemp(p : tnode;isint64 : boolean);
var
hregister : tregister;
href : treference;
begin
hregister:=getregister32;
reset_reference(href);
href.base:=procinfo^.frame_pointer;
href.offset:=p.temp_offset;
emit_ref_reg(A_MOV,S_L,href,hregister);
if (p.location.loc in [LOC_REGISTER,LOC_CREGISTER]) then
begin
p.location.register:=hregister;
if isint64 then
begin
p.location.registerhigh:=getregister32;
href.offset:=p.temp_offset+4;
emit_ref_reg(A_MOV,S_L,p.location.registerhigh);
{ set correctly for release ! }
href.offset:=p.temp_offset;
end;
end
else
begin
reset_reference(p.location.reference);
p.location.reference.base:=hregister;
{ Why is this done? We can never be sure about p^.left
because otherwise secondload fails PM
set_location(p^.left^.location,p^.location);}
end;
ungetiftemp(href);
end;
{$endif TEMPS_NOT_PUSH}
procedure pushsetelement(p : tnode);
var
hr,hr16,hr32 : tregister;
begin
{ copy the element on the stack, slightly complicated }
if p.nodetype=ordconstn then
begin
if aktalignment.paraalign=4 then
exprasmList.concat(Taicpu.Op_const(A_PUSH,S_L,tordconstnode(p).value))
else
exprasmList.concat(Taicpu.Op_const(A_PUSH,S_W,tordconstnode(p).value));
end
else
begin
case p.location.loc of
LOC_REGISTER,
LOC_CREGISTER :
begin
hr:=p.location.register;
case hr of
R_EAX,R_EBX,R_ECX,R_EDX,R_EDI,R_ESI,R_ESP :
begin
hr16:=reg32toreg16(hr);
hr32:=hr;
end;
R_AX,R_BX,R_CX,R_DX,R_DI,R_SI,R_SP :
begin
hr16:=hr;
hr32:=reg16toreg32(hr);
end;
R_AL,R_BL,R_CL,R_DL :
begin
hr16:=reg8toreg16(hr);
hr32:=reg8toreg32(hr);
end;
end;
if aktalignment.paraalign=4 then
exprasmList.concat(Taicpu.Op_reg(A_PUSH,S_L,hr32))
else
exprasmList.concat(Taicpu.Op_reg(A_PUSH,S_W,hr16));
ungetregister32(hr32);
end;
else
begin
{ you can't push more bytes than the size of the element, }
{ because this may cross a page boundary and you'll get a }
{ sigsegv (JM) }
emit_push_mem_size(p.location.reference,1);
del_reference(p.location.reference);
end;
end;
end;
end;
procedure push_value_para(p:tnode;inlined,is_cdecl:boolean;
para_offset:longint;alignment : longint);
var
tempreference : treference;
r : preference;
opsize : topsize;
op : tasmop;
hreg : tregister;
size : longint;
hlabel : tasmlabel;
begin
case p.location.loc of
LOC_REGISTER,
LOC_CREGISTER:
begin
if p.resulttype.def.size=8 then
begin
inc(pushedparasize,8);
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmlist.concat(taicpu.op_reg_ref(A_MOV,S_L,p.location.registerlow,r));
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize+4);
exprasmlist.concat(taicpu.op_reg_ref(A_MOV,S_L,p.location.registerhigh,r));
end
else
begin
exprasmlist.concat(taicpu.op_reg(A_PUSH,S_L,p.location.registerhigh));
exprasmlist.concat(taicpu.op_reg(A_PUSH,S_L,p.location.registerlow));
end;
ungetregister32(p.location.registerhigh);
ungetregister32(p.location.registerlow);
end
else case p.location.register of
R_EAX,R_EBX,R_ECX,R_EDX,R_ESI,
R_EDI,R_ESP,R_EBP :
begin
inc(pushedparasize,4);
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,p.location.register,r));
end
else
exprasmList.concat(Taicpu.Op_reg(A_PUSH,S_L,p.location.register));
ungetregister32(p.location.register);
end;
R_AX,R_BX,R_CX,R_DX,R_SI,R_DI:
begin
if alignment=4 then
begin
opsize:=S_L;
hreg:=reg16toreg32(p.location.register);
inc(pushedparasize,4);
end
else
begin
opsize:=S_W;
hreg:=p.location.register;
inc(pushedparasize,2);
end;
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,opsize,hreg,r));
end
else
exprasmList.concat(Taicpu.Op_reg(A_PUSH,opsize,hreg));
ungetregister32(reg16toreg32(p.location.register));
end;
R_AL,R_BL,R_CL,R_DL:
begin
if alignment=4 then
begin
opsize:=S_L;
hreg:=reg8toreg32(p.location.register);
inc(pushedparasize,4);
end
else
begin
opsize:=S_W;
hreg:=reg8toreg16(p.location.register);
inc(pushedparasize,2);
end;
{ we must push always 16 bit }
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,opsize,hreg,r));
end
else
exprasmList.concat(Taicpu.Op_reg(A_PUSH,opsize,hreg));
ungetregister32(reg8toreg32(p.location.register));
end;
else internalerror(1899);
end;
end;
LOC_FPU:
begin
size:=align(tfloatdef(p.resulttype.def).size,alignment);
inc(pushedparasize,size);
if not inlined then
emit_const_reg(A_SUB,S_L,size,R_ESP);
{$ifdef GDB}
if (cs_debuginfo in aktmoduleswitches) and
(exprasmList.first=exprasmList.last) then
exprasmList.concat(Tai_force_line.Create);
{$endif GDB}
r:=new_reference(R_ESP,0);
floatstoreops(tfloatdef(p.resulttype.def).typ,op,opsize);
{ this is the easiest case for inlined !! }
if inlined then
begin
r^.base:=procinfo^.framepointer;
r^.offset:=para_offset-pushedparasize;
end;
exprasmList.concat(Taicpu.Op_ref(op,opsize,r));
dec(fpuvaroffset);
end;
LOC_CFPUREGISTER:
begin
exprasmList.concat(Taicpu.Op_reg(A_FLD,S_NO,
correct_fpuregister(p.location.register,fpuvaroffset)));
size:=align(tfloatdef(p.resulttype.def).size,alignment);
inc(pushedparasize,size);
if not inlined then
emit_const_reg(A_SUB,S_L,size,R_ESP);
{$ifdef GDB}
if (cs_debuginfo in aktmoduleswitches) and
(exprasmList.first=exprasmList.last) then
exprasmList.concat(Tai_force_line.Create);
{$endif GDB}
r:=new_reference(R_ESP,0);
floatstoreops(tfloatdef(p.resulttype.def).typ,op,opsize);
{ this is the easiest case for inlined !! }
if inlined then
begin
r^.base:=procinfo^.framepointer;
r^.offset:=para_offset-pushedparasize;
end;
exprasmList.concat(Taicpu.Op_ref(op,opsize,r));
end;
LOC_REFERENCE,LOC_MEM:
begin
tempreference:=p.location.reference;
del_reference(p.location.reference);
case p.resulttype.def.deftype of
enumdef,
orddef :
begin
case p.resulttype.def.size of
8 : begin
inc(pushedparasize,8);
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,S_L,
newreference(tempreference),R_EDI);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,r));
ungetregister32(R_EDI);
getexplicitregister32(R_EDI);
inc(tempreference.offset,4);
emit_ref_reg(A_MOV,S_L,
newreference(tempreference),R_EDI);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize+4);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,r));
ungetregister32(R_EDI);
end
else
begin
inc(tempreference.offset,4);
emit_push_mem(tempreference);
dec(tempreference.offset,4);
emit_push_mem(tempreference);
end;
end;
4 : begin
inc(pushedparasize,4);
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,S_L,
newreference(tempreference),R_EDI);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,r));
ungetregister32(R_EDI);
end
else
emit_push_mem(tempreference);
end;
1,2 : begin
if alignment=4 then
begin
opsize:=S_L;
hreg:=R_EDI;
inc(pushedparasize,4);
end
else
begin
opsize:=S_W;
hreg:=R_DI;
inc(pushedparasize,2);
end;
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,opsize,
newreference(tempreference),hreg);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,opsize,hreg,r));
ungetregister32(R_EDI);
end
else
emit_push_mem_size(tempreference,p.resulttype.def.size);
end;
else
internalerror(234231);
end;
end;
floatdef :
begin
case tfloatdef(p.resulttype.def).typ of
s32real :
begin
inc(pushedparasize,4);
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,S_L,
newreference(tempreference),R_EDI);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,r));
ungetregister32(R_EDI);
end
else
emit_push_mem(tempreference);
end;
s64real,
s64comp :
begin
inc(pushedparasize,4);
inc(tempreference.offset,4);
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,S_L,
newreference(tempreference),R_EDI);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,r));
ungetregister32(R_EDI);
end
else
emit_push_mem(tempreference);
inc(pushedparasize,4);
dec(tempreference.offset,4);
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,S_L,
newreference(tempreference),R_EDI);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,r));
ungetregister32(R_EDI);
end
else
emit_push_mem(tempreference);
end;
s80real :
begin
inc(pushedparasize,4);
if alignment=4 then
inc(tempreference.offset,8)
else
inc(tempreference.offset,6);
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,S_L,
newreference(tempreference),R_EDI);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,r));
ungetregister32(R_EDI);
end
else
emit_push_mem(tempreference);
dec(tempreference.offset,4);
inc(pushedparasize,4);
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,S_L,
newreference(tempreference),R_EDI);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,r));
ungetregister32(R_EDI);
end
else
emit_push_mem(tempreference);
if alignment=4 then
begin
opsize:=S_L;
hreg:=R_EDI;
inc(pushedparasize,4);
dec(tempreference.offset,4);
end
else
begin
opsize:=S_W;
hreg:=R_DI;
inc(pushedparasize,2);
dec(tempreference.offset,2);
end;
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,opsize,
newreference(tempreference),hreg);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,opsize,hreg,r));
ungetregister32(R_EDI);
end
else
exprasmList.concat(Taicpu.Op_ref(A_PUSH,opsize,
newreference(tempreference)));
end;
end;
end;
pointerdef,
procvardef,
classrefdef:
begin
inc(pushedparasize,4);
if inlined then
begin
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,S_L,
newreference(tempreference),R_EDI);
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,S_L,R_EDI,r));
ungetregister32(R_EDI);
end
else
emit_push_mem(tempreference);
end;
arraydef,
recorddef,
stringdef,
setdef,
objectdef :
begin
{ even some structured types are 32 bit }
if is_widestring(p.resulttype.def) or
is_ansistring(p.resulttype.def) or
is_smallset(p.resulttype.def) or
((p.resulttype.def.deftype in [recorddef,arraydef]) and
(
(p.resulttype.def.deftype<>arraydef) or not
(tarraydef(p.resulttype.def).IsConstructor or
tarraydef(p.resulttype.def).isArrayOfConst or
is_open_array(p.resulttype.def))
) and
(p.resulttype.def.size<=4)
) or
is_class(p.resulttype.def) or
is_interface(p.resulttype.def) then
begin
if (p.resulttype.def.size>2) or
((alignment=4) and (p.resulttype.def.size>0)) then
begin
inc(pushedparasize,4);
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
concatcopy(tempreference,r^,4,false,false);
end
else
emit_push_mem(tempreference);
end
else
begin
if p.resulttype.def.size>0 then
begin
inc(pushedparasize,2);
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
concatcopy(tempreference,r^,2,false,false);
end
else
exprasmList.concat(Taicpu.Op_ref(A_PUSH,S_W,newreference(tempreference)));
end;
end;
end
{ call by value open array ? }
else if is_cdecl then
begin
{ push on stack }
size:=align(p.resulttype.def.size,alignment);
inc(pushedparasize,size);
emit_const_reg(A_SUB,S_L,size,R_ESP);
r:=new_reference(R_ESP,0);
concatcopy(tempreference,r^,size,false,false);
dispose(r);
end
else
internalerror(8954);
end;
else
CGMessage(cg_e_illegal_expression);
end;
end;
LOC_JUMP:
begin
getlabel(hlabel);
if alignment=4 then
begin
opsize:=S_L;
inc(pushedparasize,4);
end
else
begin
opsize:=S_W;
inc(pushedparasize,2);
end;
emitlab(truelabel);
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
emit_const_ref(A_MOV,opsize,1,r);
end
else
exprasmList.concat(Taicpu.Op_const(A_PUSH,opsize,1));
emitjmp(C_None,hlabel);
emitlab(falselabel);
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
emit_const_ref(A_MOV,opsize,0,r);
end
else
exprasmList.concat(Taicpu.Op_const(A_PUSH,opsize,0));
emitlab(hlabel);
end;
LOC_FLAGS:
begin
if not(R_EAX in unused) then
begin
getexplicitregister32(R_EDI);
emit_reg_reg(A_MOV,S_L,R_EAX,R_EDI);
end;
emit_flag2reg(p.location.resflags,R_AL);
emit_reg_reg(A_MOVZX,S_BW,R_AL,R_AX);
if alignment=4 then
begin
opsize:=S_L;
hreg:=R_EAX;
inc(pushedparasize,4);
end
else
begin
opsize:=S_W;
hreg:=R_AX;
inc(pushedparasize,2);
end;
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOV,opsize,hreg,r));
end
else
exprasmList.concat(Taicpu.Op_reg(A_PUSH,opsize,hreg));
if not(R_EAX in unused) then
begin
emit_reg_reg(A_MOV,S_L,R_EDI,R_EAX);
ungetregister32(R_EDI);
end;
end;
{$ifdef SUPPORT_MMX}
LOC_MMXREGISTER,
LOC_CMMXREGISTER:
begin
inc(pushedparasize,8); { was missing !!! (PM) }
emit_const_reg(
A_SUB,S_L,8,R_ESP);
{$ifdef GDB}
if (cs_debuginfo in aktmoduleswitches) and
(exprasmList.first=exprasmList.last) then
exprasmList.concat(Tai_force_line.Create);
{$endif GDB}
if inlined then
begin
r:=new_reference(procinfo^.framepointer,para_offset-pushedparasize);
exprasmList.concat(Taicpu.Op_reg_ref(A_MOVQ,S_NO,
p.location.register,r));
end
else
begin
r:=new_reference(R_ESP,0);
exprasmList.concat(Taicpu.Op_reg_ref(
A_MOVQ,S_NO,p.location.register,r));
end;
end;
{$endif SUPPORT_MMX}
end;
end;
{*****************************************************************************
Emit Functions
*****************************************************************************}
procedure maketojumpbool(p : tnode);
{
produces jumps to true respectively false labels using boolean expressions
}
var
opsize : topsize;
storepos : tfileposinfo;
begin
if nf_error in p.flags then
exit;
storepos:=aktfilepos;
aktfilepos:=p.fileinfo;
if is_boolean(p.resulttype.def) then
begin
load_all_regvars(exprasmlist);
if is_constboolnode(p) then
begin
if tordconstnode(p).value<>0 then
emitjmp(C_None,truelabel)
else
emitjmp(C_None,falselabel);
end
else
begin
opsize:=def_opsize(p.resulttype.def);
case p.location.loc of
LOC_CREGISTER,LOC_REGISTER : begin
emit_reg_reg(A_OR,opsize,p.location.register,
p.location.register);
ungetregister(p.location.register);
emitjmp(C_NZ,truelabel);
emitjmp(C_None,falselabel);
end;
LOC_MEM,LOC_REFERENCE : begin
emit_const_ref(
A_CMP,opsize,0,newreference(p.location.reference));
del_reference(p.location.reference);
emitjmp(C_NZ,truelabel);
emitjmp(C_None,falselabel);
end;
LOC_FLAGS : begin
emitjmp(flag_2_cond[p.location.resflags],truelabel);
emitjmp(C_None,falselabel);
end;
end;
end;
end
else
CGMessage(type_e_mismatch);
aktfilepos:=storepos;
end;
{ produces if necessary overflowcode }
procedure emitoverflowcheck(p:tnode);
var
hl : tasmlabel;
begin
if not(cs_check_overflow in aktlocalswitches) then
exit;
getlabel(hl);
if not ((p.resulttype.def.deftype=pointerdef) or
((p.resulttype.def.deftype=orddef) and
(torddef(p.resulttype.def).typ in [u64bit,u16bit,u32bit,u8bit,uchar,
bool8bit,bool16bit,bool32bit]))) then
emitjmp(C_NO,hl)
else
emitjmp(C_NB,hl);
emitcall('FPC_OVERFLOW');
emitlab(hl);
end;
{ produces range check code, while one of the operands is a 64 bit
integer }
procedure emitrangecheck64(p : tnode;todef : tdef);
var
neglabel,
poslabel,
endlabel: tasmlabel;
href : preference;
hreg : tregister;
hdef : torddef;
fromdef : tdef;
opcode : tasmop;
opsize : topsize;
oldregisterdef: boolean;
from_signed,to_signed: boolean;
begin
fromdef:=p.resulttype.def;
from_signed := is_signed(fromdef);
to_signed := is_signed(todef);
if not is_64bitint(todef) then
begin
oldregisterdef := registerdef;
registerdef := false;
{ get the high dword in a register }
if p.location.loc in [LOC_REGISTER,LOC_CREGISTER] then
hreg := p.location.registerhigh
else
begin
hreg := getexplicitregister32(R_EDI);
href := newreference(p.location.reference);
inc(href^.offset,4);
emit_ref_reg(A_MOV,S_L,href,hreg);
end;
getlabel(poslabel);
{ check high dword, must be 0 (for positive numbers) }
emit_reg_reg(A_TEST,S_L,hreg,hreg);
emitjmp(C_E,poslabel);
{ It can also be $ffffffff, but only for negative numbers }
if from_signed and to_signed then
begin
getlabel(neglabel);
emit_const_reg(A_CMP,S_L,longint($ffffffff),hreg);
emitjmp(C_E,neglabel);
end;
if hreg = R_EDI then
ungetregister32(hreg);
{ For all other values we have a range check error }
emitcall('FPC_RANGEERROR');
{ if the high dword = 0, the low dword can be considered a }
{ simple cardinal }
emitlab(poslabel);
hdef:=torddef.create(u32bit,0,longint($ffffffff));
{ the real p.resulttype.def is already saved in fromdef }
p.resulttype.def := hdef;
emitrangecheck(p,todef);
hdef.free;
{ restore original resulttype.def }
p.resulttype.def := todef;
if from_signed and to_signed then
begin
getlabel(endlabel);
emitjmp(C_None,endlabel);
{ if the high dword = $ffffffff, then the low dword (when }
{ considered as a longint) must be < 0 }
emitlab(neglabel);
if p.location.loc in [LOC_REGISTER,LOC_CREGISTER] then
hreg := p.location.registerlow
else
begin
hreg := getexplicitregister32(R_EDI);
emit_ref_reg(A_MOV,S_L,
newreference(p.location.reference),hreg);
end;
{ get a new neglabel (JM) }
getlabel(neglabel);
emit_reg_reg(A_TEST,S_L,hreg,hreg);
if hreg = R_EDI then
ungetregister32(hreg);
emitjmp(C_L,neglabel);
emitcall('FPC_RANGEERROR');
{ if we get here, the 64bit value lies between }
{ longint($80000000) and -1 (JM) }
emitlab(neglabel);
hdef:=torddef.create(s32bit,longint($80000000),-1);
p.resulttype.def := hdef;
emitrangecheck(p,todef);
hdef.free;
emitlab(endlabel);
end;
registerdef := oldregisterdef;
p.resulttype.def := fromdef;
{ restore p's resulttype.def }
end
else
{ todef = 64bit int }
{ no 64bit subranges supported, so only a small check is necessary }
{ if both are signed or both are unsigned, no problem! }
if (from_signed xor to_signed) and
{ also not if the fromdef is unsigned and < 64bit, since that will }
{ always fit in a 64bit int (todef is 64bit) }
(from_signed or
(torddef(fromdef).typ = u64bit)) then
begin
{ in all cases, there is only a problem if the higest bit is set }
if p.location.loc in [LOC_REGISTER,LOC_CREGISTER] then
if is_64bitint(fromdef) then
hreg := p.location.registerhigh
else
hreg := p.location.register
else
begin
hreg := getexplicitregister32(R_EDI);
case p.resulttype.def.size of
1: opsize := S_BL;
2: opsize := S_WL;
4,8: opsize := S_L;
end;
if opsize in [S_BL,S_WL] then
if from_signed then
opcode := A_MOVSX
else opcode := A_MOVZX
else
opcode := A_MOV;
href := newreference(p.location.reference);
if p.resulttype.def.size = 8 then
inc(href^.offset,4);
emit_ref_reg(opcode,opsize,href,hreg);
end;
getlabel(poslabel);
emit_reg_reg(A_TEST,regsize(hreg),hreg,hreg);
if hreg = R_EDI then
ungetregister32(hreg);
emitjmp(C_GE,poslabel);
emitcall('FPC_RANGEERROR');
emitlab(poslabel);
end;
end;
{ produces if necessary rangecheckcode }
procedure emitrangecheck(p:tnode;todef:tdef);
{
generate range checking code for the value at location t. The
type used is the checked against todefs ranges. fromdef (p.resulttype.def)
is the original type used at that location, when both defs are
equal the check is also insert (needed for succ,pref,inc,dec)
}
var
neglabel : tasmlabel;
opsize : topsize;
op : tasmop;
fromdef : tdef;
lto,hto,
lfrom,hfrom : longint;
is_reg : boolean;
begin
{ range checking on and range checkable value? }
if not(cs_check_range in aktlocalswitches) or
not(todef.deftype in [orddef,enumdef,arraydef]) then
exit;
{ only check when assigning to scalar, subranges are different,
when todef=fromdef then the check is always generated }
fromdef:=p.resulttype.def;
{ no range check if from and to are equal and are both longint/dword or }
{ int64/qword, since such operations can at most cause overflows (JM) }
if (fromdef = todef) and
{ then fromdef and todef can only be orddefs }
(((torddef(fromdef).typ = s32bit) and
(torddef(fromdef).low = longint($80000000)) and
(torddef(fromdef).high = $7fffffff)) or
((torddef(fromdef).typ = u32bit) and
(torddef(fromdef).low = 0) and
(torddef(fromdef).high = longint($ffffffff))) or
is_64bitint(fromdef)) then
exit;
if is_64bitint(fromdef) or is_64bitint(todef) then
begin
emitrangecheck64(p,todef);
exit;
end;
{we also need lto and hto when checking if we need to use doublebound!
(JM)}
getrange(todef,lto,hto);
if todef<>fromdef then
begin
getrange(p.resulttype.def,lfrom,hfrom);
{ first check for not being u32bit, then if the to is bigger than
from }
if (lto<hto) and (lfrom<hfrom) and
(lto<=lfrom) and (hto>=hfrom) then
exit;
end;
{ generate the rangecheck code for the def where we are going to
store the result }
{ get op and opsize }
opsize:=def2def_opsize(fromdef,u32bittype.def);
if opsize in [S_B,S_W,S_L] then
op:=A_MOV
else
if is_signed(fromdef) then
op:=A_MOVSX
else
op:=A_MOVZX;
is_reg:=(p.location.loc in [LOC_REGISTER,LOC_CREGISTER]);
getexplicitregister32(R_EDI);
{ use the trick that }
{ a <= x <= b <=> 0 <= x-a <= b-a <=> cardinal(x-a) <= cardinal(b-a) }
{ To be able to do that, we have to make sure however that either }
{ fromdef and todef are both signed or unsigned, or that we leave }
{ the parts < 0 and > maxlongint out }
{ is_signed now also works for arrays (it checks the rangetype) (JM) }
if is_signed(fromdef) xor is_signed(todef) then
if is_signed(fromdef) then
{ from is signed, to is unsigned }
begin
{ if high(from) < 0 -> always range error }
if (hfrom < 0) or
{ if low(to) > maxlongint (== < 0, since we only have }
{ longints here), also range error }
(lto < 0) then
begin
emitcall('FPC_RANGEERROR');
exit
end;
{ to is unsigned -> hto < 0 == hto > maxlongint }
{ since from is signed, values > maxlongint are < 0 and must }
{ be rejected }
if hto < 0 then
hto := maxlongint;
end
else
{ from is unsigned, to is signed }
begin
if (lfrom < 0) or
(hto < 0) then
begin
emitcall('FPC_RANGEERROR');
exit
end;
{ since from is unsigned, values > maxlongint are < 0 and must }
{ be rejected }
if lto < 0 then
lto := 0;
end;
if is_reg and
(opsize = S_L) then
emit_ref_reg(A_LEA,opsize,new_reference(p.location.register,-lto),
R_EDI)
else
begin
if is_reg then
emit_reg_reg(op,opsize,p.location.register,R_EDI)
else
emit_ref_reg(op,opsize,newreference(p.location.reference),R_EDI);
if lto <> 0 then
emit_const_reg(A_SUB,S_L,lto,R_EDI);
end;
emit_const_reg(A_CMP,S_L,hto-lto,R_EDI);
ungetregister32(R_EDI);
getlabel(neglabel);
emitjmp(C_BE,neglabel);
emitcall('FPC_RANGEERROR');
emitlab(neglabel);
end;
{ DO NOT RELY on the fact that the tnode is not yet swaped
because of inlining code PM }
procedure firstcomplex(p : tbinarynode);
var
hp : tnode;
begin
{ always calculate boolean AND and OR from left to right }
if (p.nodetype in [orn,andn]) and
(p.left.resulttype.def.deftype=orddef) and
(torddef(p.left.resulttype.def).typ in [bool8bit,bool16bit,bool32bit]) then
begin
{ p.swaped:=false}
if nf_swaped in p.flags then
internalerror(234234);
end
else
if (p.left.registers32<p.right.registers32) and
{ the following check is appropriate, because all }
{ 4 registers are rarely used and it is thereby }
{ achieved that the extra code is being dropped }
{ by exchanging not commutative operators }
(p.right.registers32<=4) then
begin
hp:=p.left;
p.left:=p.right;
p.right:=hp;
if nf_swaped in p.flags then
exclude(p.flags,nf_swaped)
else
include(p.flags,nf_swaped);
end;
{else
p.swaped:=false; do not modify }
end;
{*****************************************************************************
Emit Functions
*****************************************************************************}
procedure push_shortstring_length(p:tnode);
var
hightree : tnode;
srsym : tsym;
begin
if is_open_string(p.resulttype.def) then
begin
srsym:=searchsymonlyin(tloadnode(p).symtable,'high'+tvarsym(tloadnode(p).symtableentry).name);
hightree:=cloadnode.create(tvarsym(srsym),tloadnode(p).symtable);
firstpass(hightree);
secondpass(hightree);
push_value_para(hightree,false,false,0,4);
hightree.free;
hightree:=nil;
end
else
begin
push_int(tstringdef(p.resulttype.def).len);
end;
end;
{*****************************************************************************
String functions
*****************************************************************************}
procedure loadshortstring(source,dest : tnode);
{
Load a string, handles stringdef and orddef (char) types
}
var
href: treference;
begin
case source.resulttype.def.deftype of
stringdef:
begin
if (source.nodetype=stringconstn) and
(str_length(source)=0) then
emit_const_ref(
A_MOV,S_B,0,newreference(dest.location.reference))
else
begin
emitpushreferenceaddr(dest.location.reference);
emitpushreferenceaddr(source.location.reference);
push_shortstring_length(dest);
emitcall('FPC_SHORTSTR_COPY');
maybe_loadself;
end;
end;
orddef:
begin
if source.nodetype=ordconstn then
emit_const_ref(
A_MOV,S_W,tordconstnode(source).value*256+1,newreference(dest.location.reference))
else
begin
if (source.location.loc in [LOC_REGISTER,LOC_CREGISTER]) then
begin
href := dest.location.reference;
emit_const_ref(A_MOV,S_B,1,newreference(href));
inc(href.offset,1);
emit_reg_ref(A_MOV,S_B,makereg8(source.location.register),
newreference(href));
ungetregister(source.location.register);
end
else
{ not so elegant (goes better with extra register }
begin
{ not "movl", because then we may read past the }
{ end of the heap! "movw" would be ok too, but }
{ I don't think that would be faster (JM) }
getexplicitregister32(R_EDI);
emit_ref_reg(A_MOVZX,S_BL,newreference(source.location.reference),R_EDI);
del_reference(source.location.reference);
emit_const_reg(A_SHL,S_L,8,R_EDI);
emit_const_reg(A_OR,S_L,1,R_EDI);
emit_reg_ref(A_MOV,S_W,R_DI,newreference(dest.location.reference));
ungetregister32(R_EDI);
end;
end;
end;
else
CGMessage(type_e_mismatch);
end;
end;
procedure loadlongstring(p:tbinarynode);
{
Load a string, handles stringdef and orddef (char) types
}
var
r : preference;
begin
case p.right.resulttype.def.deftype of
stringdef:
begin
if (p.right.nodetype=stringconstn) and
(str_length(p.right)=0) then
emit_const_ref(A_MOV,S_L,0,newreference(p.left.location.reference))
else
begin
emitpushreferenceaddr(p.left.location.reference);
emitpushreferenceaddr(p.right.location.reference);
push_shortstring_length(p.left);
emitcall('FPC_LONGSTR_COPY');
maybe_loadself;
end;
end;
orddef:
begin
emit_const_ref(A_MOV,S_L,1,newreference(p.left.location.reference));
r:=newreference(p.left.location.reference);
inc(r^.offset,4);
if p.right.nodetype=ordconstn then
emit_const_ref(A_MOV,S_B,tordconstnode(p.right).value,r)
else
begin
case p.right.location.loc of
LOC_REGISTER,LOC_CREGISTER:
begin
emit_reg_ref(A_MOV,S_B,p.right.location.register,r);
ungetregister(p.right.location.register);
end;
LOC_MEM,LOC_REFERENCE:
begin
if not(R_EAX in unused) then
emit_reg(A_PUSH,S_L,R_EAX);
emit_ref_reg(A_MOV,S_B,newreference(p.right.location.reference),R_AL);
emit_reg_ref(A_MOV,S_B,R_AL,r);
if not(R_EAX in unused) then
emit_reg(A_POP,S_L,R_EAX);
del_reference(p.right.location.reference);
end
else
internalerror(20799);
end;
end;
end;
else
CGMessage(type_e_mismatch);
end;
end;
procedure loadansi2short(source,dest : tnode);
var
pushed : tpushed;
regs_to_push: byte;
begin
{ Find out which registers have to be pushed (JM) }
regs_to_push := $ff;
remove_non_regvars_from_loc(source.location,regs_to_push);
{ Push them (JM) }
pushusedregisters(pushed,regs_to_push);
case source.location.loc of
LOC_REFERENCE,LOC_MEM:
begin
{ Now release the location and registers (see cgai386.pas: }
{ loadansistring for more info on the order) (JM) }
ungetiftemp(source.location.reference);
del_reference(source.location.reference);
emit_push_mem(source.location.reference);
end;
LOC_REGISTER,LOC_CREGISTER:
begin
emit_reg(A_PUSH,S_L,source.location.register);
{ Now release the register (JM) }
ungetregister32(source.location.register);
end;
end;
push_shortstring_length(dest);
emitpushreferenceaddr(dest.location.reference);
saveregvars($ff);
emitcall('FPC_ANSISTR_TO_SHORTSTR');
popusedregisters(pushed);
maybe_loadself;
end;
procedure loadwide2short(source,dest : tnode);
var
pushed : tpushed;
regs_to_push: byte;
begin
{ Find out which registers have to be pushed (JM) }
regs_to_push := $ff;
remove_non_regvars_from_loc(source.location,regs_to_push);
{ Push them (JM) }
pushusedregisters(pushed,regs_to_push);
case source.location.loc of
LOC_REFERENCE,LOC_MEM:
begin
{ Now release the location and registers (see cgai386.pas: }
{ loadansistring for more info on the order) (JM) }
ungetiftemp(source.location.reference);
del_reference(source.location.reference);
emit_push_mem(source.location.reference);
end;
LOC_REGISTER,LOC_CREGISTER:
begin
emit_reg(A_PUSH,S_L,source.location.register);
{ Now release the register (JM) }
ungetregister32(source.location.register);
end;
end;
push_shortstring_length(dest);
emitpushreferenceaddr(dest.location.reference);
saveregvars($ff);
emitcall('FPC_WIDESTR_TO_SHORTSTR');
popusedregisters(pushed);
maybe_loadself;
end;
procedure loadinterfacecom(p: tbinarynode);
{
copies an com interface from n.right to n.left, we
assume, that both sides are com interface, firstassignement have
to take care of that, an com interface can't be a register variable
}
var
pushed : tpushed;
ungettemp : boolean;
begin
{ before pushing any parameter, we have to save all used }
{ registers, but before that we have to release the }
{ registers of that node to save uneccessary pushed }
{ so be careful, if you think you can optimize that code (FK) }
{ nevertheless, this has to be changed, because otherwise the }
{ register is released before it's contents are pushed -> }
{ problems with the optimizer (JM) }
del_reference(p.left.location.reference);
ungettemp:=false;
case p.right.location.loc of
LOC_REGISTER,LOC_CREGISTER:
begin
pushusedregisters(pushed, $ff xor ($80 shr byte(p.right.location.register)));
exprasmList.concat(Taicpu.Op_reg(A_PUSH,S_L,p.right.location.register));
ungetregister32(p.right.location.register);
end;
LOC_REFERENCE,LOC_MEM:
begin
pushusedregisters(pushed,$ff
xor ($80 shr byte(p.right.location.reference.base))
xor ($80 shr byte(p.right.location.reference.index)));
emit_push_mem(p.right.location.reference);
del_reference(p.right.location.reference);
ungettemp:=true;
end;
end;
emitpushreferenceaddr(p.left.location.reference);
del_reference(p.left.location.reference);
saveregvars($ff);
emitcall('FPC_INTF_ASSIGN');
maybe_loadself;
popusedregisters(pushed);
if ungettemp then
ungetiftemp(p.right.location.reference);
end;
end.
{
$Log$
Revision 1.20 2001-08-26 13:37:01 florian
* some cg reorganisation
* some PPC updates
Revision 1.19 2001/08/24 12:22:14 jonas
* fixed memory leak with coping of array-of-consts as valuepara
Revision 1.18 2001/07/08 21:00:18 peter
* various widestring updates, it works now mostly without charset
mapping supported
Revision 1.17 2001/07/01 20:16:20 peter
* alignmentinfo record added
* -Oa argument supports more alignment settings that can be specified
per type: PROC,LOOP,VARMIN,VARMAX,CONSTMIN,CONSTMAX,RECORDMIN
RECORDMAX,LOCALMIN,LOCALMAX. It is possible to set the mimimum
required alignment and the maximum usefull alignment. The final
alignment will be choosen per variable size dependent on these
settings
Revision 1.16 2001/04/18 22:02:03 peter
* registration of targets and assemblers
Revision 1.15 2001/04/13 01:22:19 peter
* symtable change to classes
* range check generation and errors fixed, make cycle DEBUG=1 works
* memory leaks fixed
Revision 1.14 2001/04/02 21:20:39 peter
* resulttype rewrite
Revision 1.13 2001/03/11 22:58:52 peter
* getsym redesign, removed the globals srsym,srsymtable
Revision 1.12 2001/03/04 10:26:56 jonas
* new rangecheck code now handles conversion between signed and cardinal types correctly
Revision 1.11 2001/03/03 12:41:22 jonas
* simplified and optimized range checking code, FPC_BOUNDCHECK is no longer necessary
Revision 1.10 2000/12/31 11:02:12 jonas
* optimized loadshortstring a bit
Revision 1.9 2000/12/25 00:07:33 peter
+ new tlinkedlist class (merge of old tstringqueue,tcontainer and
tlinkedlist objects)
Revision 1.8 2000/12/11 19:10:19 jonas
* fixed web bug 1144
+ implemented range checking for 64bit types
Revision 1.7 2000/12/07 17:19:46 jonas
* new constant handling: from now on, hex constants >$7fffffff are
parsed as unsigned constants (otherwise, $80000000 got sign extended
and became $ffffffff80000000), all constants in the longint range
become longints, all constants >$7fffffff and <=cardinal($ffffffff)
are cardinals and the rest are int64's.
* added lots of longint typecast to prevent range check errors in the
compiler and rtl
* type casts of symbolic ordinal constants are now preserved
* fixed bug where the original resulttype.def wasn't restored correctly
after doing a 64bit rangecheck
Revision 1.6 2000/12/05 11:44:34 jonas
+ new integer regvar handling, should be much more efficient
Revision 1.5 2000/11/29 00:30:49 florian
* unused units removed from uses clause
* some changes for widestrings
Revision 1.4 2000/11/13 14:47:46 jonas
* support for range checking when converting from 64bit to something
smaller (32bit, 16bit, 8bit)
* fixed range checking between longint/cardinal and for array indexing
with cardinal (values > $7fffffff were considered negative)
Revision 1.3 2000/11/04 14:25:25 florian
+ merged Attila's changes for interfaces, not tested yet
Revision 1.2 2000/10/31 22:02:57 peter
* symtable splitted, no real code changes
Revision 1.1 2000/10/15 09:33:32 peter
* moved n386*.pas to i386/ cpu_target dir
Revision 1.3 2000/10/14 21:52:54 peter
* fixed memory leaks
Revision 1.2 2000/10/14 10:14:50 peter
* moehrendorf oct 2000 rewrite
Revision 1.1 2000/10/01 19:58:40 peter
* new file
}