fpc/compiler/regvars.pas
2003-05-30 18:55:21 +00:00

742 lines
28 KiB
ObjectPascal

{
$Id$
Copyright (c) 1998-2002 by Florian Klaempfl and Jonas Maebe
This unit handles register variable allocation
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 regvars;
{$i fpcdefs.inc}
interface
uses
aasmbase,aasmtai,aasmcpu,
node,
symsym,
cpubase, cginfo, tgobj, rgobj;
procedure assign_regvars(p: tnode);
procedure load_regvars(asml: TAAsmoutput; p: tnode);
procedure cleanup_regvars(asml: TAAsmoutput);
procedure store_regvar(asml: TAAsmoutput; reg: tregister);
procedure load_regvar(asml: TAAsmoutput; vsym: tvarsym);
procedure load_regvar_reg(asml: TAAsmoutput; reg: tregister);
procedure load_all_regvars(asml: TAAsmoutput);
{$ifdef i386}
procedure sync_regvars_other(list1, list2: taasmoutput; const regvarsloaded1,
regvarsloaded2: regvarother_booleanarray);
procedure sync_regvars_int(list1, list2: taasmoutput; const regvarsloaded1,
regvarsloaded2: Tsupregset);
{$endif i386}
implementation
uses
globtype,systems,comphook,
cutils,cclasses,verbose,globals,
symconst,symbase,symtype,symdef,paramgr,defutil,
cgbase,cgobj,rgcpu;
procedure searchregvars(p : tnamedindexitem;arg:pointer);
var
i,j,k : longint;
parasym : boolean;
begin
parasym:=pboolean(arg)^;
if (tsym(p).typ=varsym) and (vo_regable in tvarsym(p).varoptions) then
begin
j:=tvarsym(p).refs;
{ parameter get a less value }
if parasym then
begin
if cs_littlesize in aktglobalswitches then
dec(j,1)
else
dec(j,100);
end;
{ walk through all momentary register variables }
for i:=1 to maxvarregs do
begin
with pregvarinfo(current_procdef.regvarinfo)^ do
if ((regvars[i]=nil) or (j>regvars_refs[i])) and (j>0) then
begin
for k:=maxvarregs-1 downto i do
begin
regvars[k+1]:=regvars[k];
regvars_para[k+1]:=regvars_para[k];
regvars_refs[k+1]:=regvars_refs[k];
end;
{ calc the new refs
tvarsym(p).refs:=j; }
regvars[i]:=tvarsym(p);
regvars_para[i]:=parasym;
regvars_refs[i]:=j;
break;
end;
end;
end;
end;
procedure searchfpuregvars(p : tnamedindexitem;arg:pointer);
var
i,j,k : longint;
parasym : boolean;
begin
parasym:=pboolean(arg)^;
if (tsym(p).typ=varsym) and (vo_fpuregable in tvarsym(p).varoptions) then
begin
j:=tvarsym(p).refs;
{ parameter get a less value }
if parasym then
begin
if cs_littlesize in aktglobalswitches then
dec(j,1)
else
dec(j,100);
end;
{ walk through all momentary register variables }
for i:=1 to maxfpuvarregs do
begin
with pregvarinfo(current_procdef.regvarinfo)^ do
if ((fpuregvars[i]=nil) or (j>fpuregvars_refs[i])) and (j>0) then
begin
for k:=maxfpuvarregs-1 downto i do
begin
fpuregvars[k+1]:=fpuregvars[k];
fpuregvars_para[k+1]:=fpuregvars_para[k];
fpuregvars_refs[k+1]:=fpuregvars_refs[k];
end;
{ calc the new refs
tvarsym(p).refs:=j; }
fpuregvars[i]:=tvarsym(p);
fpuregvars_para[i]:=parasym;
fpuregvars_refs[i]:=j;
break;
end;
end;
end;
end;
procedure assign_regvars(p: tnode);
{ register variables }
var
regvarinfo: pregvarinfo;
i: longint;
parasym : boolean;
r : Tregister;
siz : tcgsize;
begin
{ max. optimizations }
{ only if no asm is used }
{ and no try statement }
if (cs_regalloc in aktglobalswitches) and
not(pi_uses_asm in current_procinfo.flags) and
not(pi_uses_exceptions in current_procinfo.flags) then
begin
new(regvarinfo);
fillchar(regvarinfo^,sizeof(regvarinfo^),0);
current_procdef.regvarinfo := regvarinfo;
if (p.registers32<maxvarregs) then
begin
parasym:=false;
symtablestack.foreach_static({$ifdef FPCPROCVAR}@{$endif}searchregvars,@parasym);
{ copy parameter into a register ? }
parasym:=true;
symtablestack.next.foreach_static({$ifdef FPCPROCVAR}@{$endif}searchregvars,@parasym);
{ hold needed registers free }
for i:=maxvarregs downto maxvarregs-p.registers32+1 do
begin
regvarinfo^.regvars[i]:=nil;
regvarinfo^.regvars_para[i] := false;
end;
{ now assign register }
for i:=1 to maxvarregs-p.registers32 do
begin
if assigned(regvarinfo^.regvars[i]) and
(rg.reg_pushes_int[varregs[i]] < regvarinfo^.regvars[i].refs) then
begin
{ register is no longer available for }
{ expressions }
{ search the register which is the most }
{ unused }
rg.makeregvarint(varregs[i]);
{ call by reference/const ? }
if (regvarinfo^.regvars[i].varspez in [vs_var,vs_out]) or
((regvarinfo^.regvars[i].varspez=vs_const) and
paramanager.push_addr_param(regvarinfo^.regvars[i].vartype.def,current_procdef.proccalloption)) then
siz:=OS_32
else
if (regvarinfo^.regvars[i].vartype.def.deftype in [orddef,enumdef]) and
(regvarinfo^.regvars[i].vartype.def.size=1) then
siz:=OS_8
else
if (regvarinfo^.regvars[i].vartype.def.deftype in [orddef,enumdef]) and
(regvarinfo^.regvars[i].vartype.def.size=2) then
siz:=OS_16
else
siz:=OS_32;
regvarinfo^.regvars[i].reg.enum:=R_INTREGISTER;
regvarinfo^.regvars[i].reg.number:=(varregs[i] shl 8) or cgsize2subreg(siz);
{$ifdef i386}
{ procedure uses this register }
include(rg.usedintinproc,varregs[i]);
{$endif i386}
end
else
begin
regvarinfo^.regvars[i] := nil;
regvarinfo^.regvars_para[i] := false;
end;
end;
end;
if ((p.registersfpu+1)<maxfpuvarregs) then
begin
parasym:=false;
symtablestack.foreach_static({$ifdef FPCPROCVAR}@{$endif}searchfpuregvars,@parasym);
{$ifdef dummy}
{ this code should be never enabled because }
{ 1. the caller loads parameters into registers }
{ 2. (later) the CSE loads a parameter into a }
{ register, if necessary }
{ (FK) }
{ copy parameter into a register ? }
parasym:=true;
symtablestack.next.foreach_static({$ifdef FPCPROCVAR}@{$endif}searchregvars);
{$endif dummy}
{ hold needed registers free }
{ in non leaf procedures we must be very careful }
{ with assigning registers }
if aktmaxfpuregisters=-1 then
begin
if (pi_do_call in current_procinfo.flags) then
begin
for i:=maxfpuvarregs downto 2 do
regvarinfo^.fpuregvars[i]:=nil;
end
else
begin
for i:=maxfpuvarregs downto maxfpuvarregs-p.registersfpu do
regvarinfo^.fpuregvars[i]:=nil;
end;
end
else
begin
for i:=aktmaxfpuregisters+1 to maxfpuvarregs do
regvarinfo^.fpuregvars[i]:=nil;
end;
{ now assign register }
for i:=1 to maxfpuvarregs do
begin
if assigned(regvarinfo^.fpuregvars[i]) then
begin
{$ifdef i386}
{ reserve place on the FPU stack }
r.enum:=R_ST0;
regvarinfo^.fpuregvars[i].reg:=trgcpu(rg).correct_fpuregister(r,i);
{$else i386}
regvarinfo^.fpuregvars[i].reg.enum:=fpuvarregs[i];
rg.makeregvarother(regvarinfo^.fpuregvars[i].reg);
{$endif i386}
end;
end;
end;
end;
end;
procedure store_regvar(asml: TAAsmoutput; reg: tregister);
var
i: longint;
r : tregister;
hr: treference;
regvarinfo: pregvarinfo;
vsym: tvarsym;
begin
{$ifdef i386}
regvarinfo := pregvarinfo(current_procdef.regvarinfo);
if not assigned(regvarinfo) then
exit;
if reg.enum=R_INTREGISTER then
begin
for i := 1 to maxvarregs do
if assigned(regvarinfo^.regvars[i]) and
(regvarinfo^.regvars[i].reg.number shr 8 = reg.number shr 8) then
begin
if (reg.number shr 8) in rg.regvar_loaded_int then
begin
vsym := tvarsym(regvarinfo^.regvars[i]);
{ we only have to store the regvar back to memory if it's }
{ possible that it's been modified (JM) }
if not(vsym.varspez in [vs_const,vs_var,vs_out]) then
begin
reference_reset_base(hr,current_procinfo.framepointer,vsym.adjusted_address);
cg.a_load_reg_ref(asml,def_cgsize(vsym.vartype.def),vsym.reg,hr);
end;
asml.concat(tai_regalloc.dealloc(vsym.reg));
exclude(rg.regvar_loaded_int,reg.number shr 8);
end;
break;
end;
end
else
begin
for i := 1 to maxvarregs do
if assigned(regvarinfo^.regvars[i]) then
begin
r:=rg.makeregsize(regvarinfo^.regvars[i].reg,OS_INT);
if (r.enum = reg.enum) then
begin
if rg.regvar_loaded_other[r.enum] then
begin
vsym := tvarsym(regvarinfo^.regvars[i]);
{ we only have to store the regvar back to memory if it's }
{ possible that it's been modified (JM) }
if not(vsym.varspez in [vs_const,vs_var,vs_out]) then
begin
reference_reset_base(hr,current_procinfo.framepointer,vsym.adjusted_address);
cg.a_load_reg_ref(asml,def_cgsize(vsym.vartype.def),vsym.reg,hr);
end;
asml.concat(tai_regalloc.dealloc(vsym.reg));
rg.regvar_loaded_other[r.enum] := false;
end;
break;
end;
end;
end;
{$endif i386}
end;
procedure load_regvar(asml: TAAsmoutput; vsym: tvarsym);
var
hr: treference;
opsize: tcgsize;
r,
reg : tregister;
begin
{$ifndef i386}
exit;
{$endif i386}
reg:=vsym.reg;
if reg.enum=R_INTREGISTER then
begin
if not((reg.number shr 8) in rg.regvar_loaded_int) then
begin
asml.concat(tai_regalloc.alloc(reg));
reference_reset_base(hr,current_procinfo.framepointer,vsym.adjusted_address);
if (vsym.varspez in [vs_var,vs_out]) or
((vsym.varspez=vs_const) and
paramanager.push_addr_param(vsym.vartype.def,current_procdef.proccalloption)) then
opsize := OS_ADDR
else
opsize := def_cgsize(vsym.vartype.def);
cg.a_load_ref_reg(asml,opsize,hr,reg);
include(rg.regvar_loaded_int,reg.number shr 8);
end;
end
else
begin
r:=rg.makeregsize(reg,OS_INT);
if not rg.regvar_loaded_other[r.enum] then
begin
asml.concat(tai_regalloc.alloc(reg));
reference_reset_base(hr,current_procinfo.framepointer,vsym.adjusted_address);
if (vsym.varspez in [vs_var,vs_out]) or
((vsym.varspez=vs_const) and
paramanager.push_addr_param(vsym.vartype.def,current_procdef.proccalloption)) then
opsize := OS_ADDR
else
opsize := def_cgsize(vsym.vartype.def);
cg.a_load_ref_reg(asml,opsize,hr,reg);
rg.regvar_loaded_other[r.enum] := true;
end;
end;
end;
procedure load_regvar_reg(asml: TAAsmoutput; reg: tregister);
var
i: longint;
regvarinfo: pregvarinfo;
reg_spare : tregister;
begin
regvarinfo := pregvarinfo(current_procdef.regvarinfo);
if not assigned(regvarinfo) then
exit;
if reg.enum=R_INTREGISTER then
begin
for i := 1 to maxvarregs do
if assigned(regvarinfo^.regvars[i]) and
(regvarinfo^.regvars[i].reg.number shr 8 = reg.number shr 8) then
load_regvar(asml,tvarsym(regvarinfo^.regvars[i]))
end
else
begin
reg_spare := rg.makeregsize(reg,OS_INT);
if reg_spare.enum>lastreg then
internalerror(2003010801);
for i := 1 to maxvarregs do
if assigned(regvarinfo^.regvars[i]) and
(rg.makeregsize(regvarinfo^.regvars[i].reg,OS_INT).enum = reg_spare.enum) then
load_regvar(asml,tvarsym(regvarinfo^.regvars[i]))
end;
end;
procedure load_all_regvars(asml: TAAsmoutput);
var
i: longint;
regvarinfo: pregvarinfo;
begin
regvarinfo := pregvarinfo(current_procdef.regvarinfo);
if not assigned(regvarinfo) then
exit;
for i := 1 to maxvarregs do
if assigned(regvarinfo^.regvars[i]) then
load_regvar(asml,tvarsym(regvarinfo^.regvars[i]))
end;
procedure load_regvars(asml: TAAsmoutput; p: tnode);
var
i: longint;
regvarinfo: pregvarinfo;
r:Tregister;
begin
if (cs_regalloc in aktglobalswitches) and
not(pi_uses_asm in current_procinfo.flags) and
not(pi_uses_exceptions in current_procinfo.flags) then
begin
regvarinfo := pregvarinfo(current_procdef.regvarinfo);
{ can happen when inlining assembler procedures (JM) }
if not assigned(regvarinfo) then
exit;
for i:=1 to maxvarregs do
begin
if assigned(regvarinfo^.regvars[i]) then
begin
r:=regvarinfo^.regvars[i].reg;
convert_register_to_enum(r);
if cs_asm_source in aktglobalswitches then
asml.insert(tai_comment.Create(strpnew(regvarinfo^.regvars[i].name+
' with weight '+tostr(regvarinfo^.regvars[i].refs)+' assigned to register '+
std_reg2str[r.enum])));
Message3(cg_d_register_weight,std_reg2str[r.enum],
tostr(regvarinfo^.regvars[i].refs),regvarinfo^.regvars[i].name);
end;
end;
for i:=1 to maxfpuvarregs do
begin
if assigned(regvarinfo^.fpuregvars[i]) then
begin
{$ifdef i386}
r.enum:=R_ST0;
{ reserve place on the FPU stack }
regvarinfo^.fpuregvars[i].reg:=trgcpu(rg).correct_fpuregister(r,i-1);
asml.concat(Taicpu.op_none(A_FLDZ,S_NO));
{$endif i386}
end;
end;
{$ifdef i386}
if assigned(p) then
if cs_asm_source in aktglobalswitches then
asml.insert(tai_comment.Create(strpnew(tostr(p.registersfpu)+
' registers on FPU stack used by temp. expressions')));
{$endif i386}
for i:=1 to maxfpuvarregs do
begin
if assigned(regvarinfo^.fpuregvars[i]) then
begin
if cs_asm_source in aktglobalswitches then
asml.insert(tai_comment.Create(strpnew(regvarinfo^.fpuregvars[i].name+
' with weight '+tostr(regvarinfo^.fpuregvars[i].refs)+' assigned to register '+
std_reg2str[regvarinfo^.fpuregvars[i].reg.enum])));
if (status.verbosity and v_debug)=v_debug then
Message3(cg_d_register_weight,std_reg2str[regvarinfo^.fpuregvars[i].reg.enum],
tostr(regvarinfo^.fpuregvars[i].refs),regvarinfo^.fpuregvars[i].name);
end;
end;
if cs_asm_source in aktglobalswitches then
asml.insert(tai_comment.Create(strpnew('Register variable assignment:')));
end;
end;
{$ifdef i386}
procedure sync_regvars_other(list1, list2: taasmoutput; const regvarsloaded1,
regvarsloaded2: regvarother_booleanarray);
var
counter: tregister;
begin
for counter.enum := low(rg.regvar_loaded_other) to high(rg.regvar_loaded_other) do
begin
rg.regvar_loaded_other[counter.enum] := regvarsloaded1[counter.enum] and
regvarsloaded2[counter.enum];
if regvarsloaded1[counter.enum] xor regvarsloaded2[counter.enum] then
if regvarsloaded1[counter.enum] then
load_regvar_reg(list2,counter)
else
load_regvar_reg(list1,counter);
end;
end;
procedure sync_regvars_int(list1, list2: taasmoutput; const regvarsloaded1,
regvarsloaded2: Tsupregset);
var
i : longint;
r : tregister;
begin
for i:=1 to maxvarregs do
begin
r.enum:=R_INTREGISTER;
r.number:=varregs[i] shl 8;
if (varregs[i] in regvarsloaded1) and
not(varregs[i] in regvarsloaded2) then
load_regvar_reg(list2,r)
else
if (varregs[i] in regvarsloaded2) and
not(varregs[i] in regvarsloaded1) then
load_regvar_reg(list1,r);
end;
end;
{$endif i386}
procedure cleanup_regvars(asml: TAAsmoutput);
var
i: longint;
r,reg : tregister;
begin
{ can happen when inlining assembler procedures (JM) }
if not assigned(current_procdef.regvarinfo) then
exit;
if (cs_regalloc in aktglobalswitches) and
not(pi_uses_asm in current_procinfo.flags) and
not(pi_uses_exceptions in current_procinfo.flags) then
with pregvarinfo(current_procdef.regvarinfo)^ do
begin
{$ifdef i386}
r.enum:=R_ST0;
for i:=1 to maxfpuvarregs do
if assigned(fpuregvars[i]) then
{ ... and clean it up }
asml.concat(Taicpu.op_reg(A_FSTP,S_NO,r));
{$endif i386}
for i := 1 to maxvarregs do
begin
if assigned(regvars[i]) then
begin
reg:=regvars[i].reg;
if reg.enum=R_INTREGISTER then
begin
if (reg.number shr 8 in rg.regvar_loaded_int) then
asml.concat(tai_regalloc.dealloc(reg));
end
else
begin
reg.number:=(reg.number and not $ff) or cgsize2subreg(OS_INT);
r:=reg;
convert_register_to_enum(r);
if r.enum>lastreg then
internalerror(200201081);
if (rg.regvar_loaded_other[r.enum]) then
asml.concat(tai_regalloc.dealloc(reg));
end;
end;
end;
end;
end;
end.
{
$Log$
Revision 1.52 2003-05-30 18:55:21 jonas
* fixed several regvar related bugs for non-i386. make cycle with -Or now
works for ppc
Revision 1.51 2003/05/23 14:27:35 peter
* remove some unit dependencies
* current_procinfo changes to store more info
Revision 1.50 2003/05/16 14:33:31 peter
* regvar fixes
Revision 1.49 2003/05/15 18:58:53 peter
* removed selfpointer_offset, vmtpointer_offset
* tvarsym.adjusted_address
* address in localsymtable is now in the real direction
* removed some obsolete globals
Revision 1.48 2003/05/12 17:22:00 jonas
* fixed (last?) remaining -tvarsym(X).address to
tg.direction*tvarsym(X).address...
Revision 1.47 2003/04/27 11:21:34 peter
* aktprocdef renamed to current_procdef
* procinfo renamed to current_procinfo
* procinfo will now be stored in current_module so it can be
cleaned up properly
* gen_main_procsym changed to create_main_proc and release_main_proc
to also generate a tprocinfo structure
* fixed unit implicit initfinal
Revision 1.46 2003/03/28 19:16:57 peter
* generic constructor working for i386
* remove fixed self register
* esi added as address register for i386
Revision 1.45 2003/02/19 22:00:14 daniel
* Code generator converted to new register notation
- Horribily outdated todo.txt removed
Revision 1.44 2003/01/08 18:43:57 daniel
* Tregister changed into a record
Revision 1.43 2002/11/25 17:43:24 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 1.42 2002/11/18 17:31:59 peter
* pass proccalloption to ret_in_xxx and push_xxx functions
Revision 1.41 2002/08/25 19:25:20 peter
* sym.insert_in_data removed
* symtable.insertvardata/insertconstdata added
* removed insert_in_data call from symtable.insert, it needs to be
called separatly. This allows to deref the address calculation
* procedures now calculate the parast addresses after the procedure
directives are parsed. This fixes the cdecl parast problem
* push_addr_param has an extra argument that specifies if cdecl is used
or not
Revision 1.40 2002/08/18 20:06:25 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 1.39 2002/08/17 09:23:41 florian
* first part of procinfo rewrite
Revision 1.38 2002/08/06 20:55:22 florian
* first part of ppc calling conventions fix
Revision 1.37 2002/07/20 11:57:57 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 1.36 2002/07/11 14:41:30 florian
* start of the new generic parameter handling
Revision 1.35 2002/07/01 18:46:25 peter
* internal linker
* reorganized aasm layer
Revision 1.34 2002/06/24 12:43:00 jonas
* fixed errors found with new -CR code from Peter when cycling with -O2p3r
Revision 1.33 2002/05/18 13:34:17 peter
* readded missing revisions
Revision 1.32 2002/05/16 19:46:44 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 1.30 2002/05/12 16:53:10 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 1.29 2002/04/21 15:23:34 carl
+ changeregsize -> makeregsize
Revision 1.28 2002/04/19 15:46:03 peter
* mangledname rewrite, tprocdef.mangledname is now created dynamicly
in most cases and not written to the ppu
* add mangeledname_prefix() routine to generate the prefix of
manglednames depending on the current procedure, object and module
* removed static procprefix since the mangledname is now build only
on demand from tprocdef.mangledname
Revision 1.27 2002/04/15 19:44:19 peter
* fixed stackcheck that would be called recursively when a stack
error was found
* generic changeregsize(reg,size) for i386 register resizing
* removed some more routines from cga unit
* fixed returnvalue handling
* fixed default stacksize of linux and go32v2, 8kb was a bit small :-)
Revision 1.26 2002/04/15 19:04:04 carl
+ reg2str -> std_reg2str()
Revision 1.25 2002/04/06 18:13:01 jonas
* several powerpc-related additions and fixes
Revision 1.24 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 1.23 2002/03/31 20:26:36 jonas
+ a_loadfpu_* and a_loadmm_* methods in tcg
* register allocation is now handled by a class and is mostly processor
independent (+rgobj.pas and i386/rgcpu.pas)
* temp allocation is now handled by a class (+tgobj.pas, -i386\tgcpu.pas)
* some small improvements and fixes to the optimizer
* some register allocation fixes
* some fpuvaroffset fixes in the unary minus node
* push/popusedregisters is now called rg.save/restoreusedregisters and
(for i386) uses temps instead of push/pop's when using -Op3 (that code is
also better optimizable)
* fixed and optimized register saving/restoring for new/dispose nodes
* LOC_FPU locations now also require their "register" field to be set to
R_ST, not R_ST0 (the latter is used for LOC_CFPUREGISTER locations only)
- list field removed of the tnode class because it's not used currently
and can cause hard-to-find bugs
}