fpc/compiler/temp_gen.pas
1998-06-08 16:07:41 +00:00

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{
$Id$
Copyright (C) 1993-98 by Florian Klaempfl
This unit handles the temporary variables stuff for i386
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 temp_gen;
interface
uses
{$ifdef i386}
i386,
{$endif i386}
{$ifdef m68k}
m68k,
{$endif m68k}
cobjects,globals,tree,hcodegen,verbose,files,aasm;
{ generates temporary variables }
procedure resettempgen;
procedure setfirsttemp(l : longint);
function gettempsize : longint;
function gettempofsize(size : longint) : longint;
{ special call for inlined procedures }
function gettempofsizepersistant(size : longint) : longint;
{ for parameter func returns }
procedure persistanttemptonormal(pos : longint);
procedure ungettemp(pos : longint;size : longint);
procedure ungetpersistanttemp(pos : longint;size : longint);
procedure gettempofsizereference(l : longint;var ref : treference);
function istemp(const ref : treference) : boolean;
procedure ungetiftemp(const ref : treference);
implementation
type
pfreerecord = ^tfreerecord;
tfreerecord = record
next : pfreerecord;
pos : longint;
size : longint;
persistant : boolean; { used for inlined procedures }
{$ifdef EXTDEBUG}
line : longint;
{$endif}
end;
var
tmpfreelist : pfreerecord;
templist : pfreerecord;
lastoccupied : longint;
firsttemp, maxtemp : longint;
procedure resettempgen;
var
hp : pfreerecord;
begin
while assigned(tmpfreelist) do
begin
hp:=tmpfreelist;
tmpfreelist:=hp^.next;
dispose(hp);
end;
while assigned(templist) do
begin
{$ifdef EXTDEBUG}
Comment(V_Warning,'temporary assignment of size '
+tostr(templist^.size)+' from line '+tostr(templist^.line)+
+' at pos '+tostr(templist^.pos)+
' not freed at the end of the procedure');
{$endif}
hp:=templist;
templist:=hp^.next;
{$ifndef EXTDEBUG}
dispose(hp);
{$endif not EXTDEBUG}
end;
templist:=nil;
tmpfreelist:=nil;
firsttemp:=0;
maxtemp:=0;
lastoccupied:=0;
end;
procedure setfirsttemp(l : longint);
begin
{ generates problems
if (l mod 4 <> 0) then dec(l,l mod 4);}
firsttemp:=l;
maxtemp := l;
lastoccupied:=l;
end;
function gettempofsize(size : longint) : longint;
var
tl,last,hp : pfreerecord;
ofs : longint;
begin
{ this code comes from the heap management of FPC ... }
if (size mod 4)<>0 then
size:=size+(4-(size mod 4));
ofs:=0;
if assigned(tmpfreelist) then
begin
last:=nil;
hp:=tmpfreelist;
while assigned(hp) do
begin
{ first fit }
if hp^.size>=size then
begin
ofs:=hp^.pos;
if hp^.pos-size < maxtemp then
maxtemp := hp^.size-size;
{ the whole block is needed ? }
if hp^.size>size then
begin
hp^.size:=hp^.size-size;
hp^.pos:=hp^.pos-size;
end
else
begin
if assigned(last) then
last^.next:=hp^.next
else
tmpfreelist:=nil;
dispose(hp);
end;
break;
end;
last:=hp;
hp:=hp^.next;
end;
end;
{ nothing free is big enough : expand temp }
if ofs=0 then
begin
ofs:=lastoccupied-size;
lastoccupied:=lastoccupied-size;
if lastoccupied < maxtemp then
maxtemp := lastoccupied;
end;
new(tl);
tl^.pos:=ofs;
tl^.size:=size;
tl^.next:=templist;
tl^.persistant:=false;
templist:=tl;
{$ifdef EXTDEBUG}
tl^.line:=current_module^.current_inputfile^.line_no;
{$endif}
gettempofsize:=ofs;
end;
function gettempofsizepersistant(size : longint) : longint;
var
l : longint;
begin
l:=gettempofsize(size);
templist^.persistant:=true;
{$ifdef EXTDEBUG}
Comment(V_Debug,'temp managment : call to gettempofsizepersistant()'+
' with size '+tostr(size)+' returned '+tostr(l));
{$endif}
gettempofsizepersistant:=l;
end;
function gettempsize : longint;
begin
{ align local data to dwords }
if (maxtemp mod 4)<>0 then
dec(maxtemp,4+(maxtemp mod 4));
gettempsize:=-maxtemp;
end;
procedure gettempofsizereference(l : longint;var ref : treference);
begin
{ do a reset, because the reference isn't used }
reset_reference(ref);
ref.offset:=gettempofsize(l);
ref.base:=procinfo.framepointer;
end;
function istemp(const ref : treference) : boolean;
begin
{ ref.index = R_NO was missing
led to problems with local arrays
with lower bound > 0 (PM) }
istemp:=((ref.base=procinfo.framepointer) and
(ref.offset<firsttemp) and (ref.index=R_NO));
end;
procedure persistanttemptonormal(pos : longint);
var hp : pfreerecord;
begin
hp:=templist;
while assigned(hp) do
if (hp^.persistant) and (hp^.pos=pos) then
begin
{$ifdef EXTDEBUG}
Comment(V_Debug,'temp managment : persistanttemptonormal()'+
' at pos '+tostr(pos)+ ' found !');
{$endif}
hp^.persistant:=false;
exit;
end
else
hp:=hp^.next;
{$ifdef EXTDEBUG}
Comment(V_Debug,'temp managment problem : persistanttemptonormal()'+
' at pos '+tostr(pos)+ ' not found !');
{$endif}
end;
procedure ungetpersistanttemp(pos : longint;size : longint);
var
prev,hp : pfreerecord;
begin
ungettemp(pos,size);
prev:=nil;
hp:=templist;
while assigned(hp) do
begin
if (hp^.persistant) and (hp^.pos=pos) and (hp^.size=size) then
begin
if assigned(prev) then
prev^.next:=hp^.next
else
templist:=hp^.next;
{$ifdef EXTDEBUG}
Comment(V_Debug,'temp managment : ungetpersistanttemp()'+
' at pos '+tostr(pos)+ ' found !');
{$endif}
dispose(hp);
exit;
end;
prev:=hp;
hp:=hp^.next;
end;
{$ifdef EXTDEBUG}
Comment(V_Warning,'temp managment problem : ungetpersistanttemp()'+
' at pos '+tostr(pos)+ ' not found !');
{$endif}
end;
procedure ungettemp(pos : longint;size : longint);
var
hp,newhp : pfreerecord;
begin
if (size mod 4)<>0 then
size:=size+(4-(size mod 4));
if size = 0 then
exit;
if pos<=lastoccupied then
if pos=lastoccupied then
begin
lastoccupied:=pos+size;
hp:=tmpfreelist;
newhp:=nil;
while assigned(hp) do
begin
{ conneting a free block }
if hp^.pos=lastoccupied then
begin
if assigned(newhp) then newhp^.next:=nil
else tmpfreelist:=nil;
lastoccupied:=lastoccupied+hp^.size;
dispose(hp);
break;
end;
newhp:=hp;
hp:=hp^.next;
end;
end
else
begin
{$ifdef EXTDEBUG}
Comment(V_Warning,'temp managment problem : ungettemp()'+
'pos '+tostr(pos)+ '< lastoccupied '+tostr(lastoccupied)+' !');
{$endif}
end
else
begin
new(newhp);
{ size can be allways set }
newhp^.size:=size;
newhp^.pos := pos;
{ if there is no free list }
if not assigned(tmpfreelist) then
begin
{ then generate one }
tmpfreelist:=newhp;
newhp^.next:=nil;
exit;
end;
{ search the position to insert }
hp:=tmpfreelist;
while assigned(hp) do
begin
{ conneting two blocks ? }
if hp^.pos+hp^.size=pos then
begin
inc(hp^.size,size);
dispose(newhp);
break;
end
{ if the end is reached, then concat }
else if hp^.next=nil then
begin
hp^.next:=newhp;
newhp^.next:=nil;
break;
end
{ falls der n<>chste Zeiger gr<67><72>er ist, dann }
{ Einh<6E>ngen }
else if hp^.next^.pos<=pos+size then
begin
{ concat two blocks ? }
if pos+size=hp^.next^.pos then
begin
newhp^.next:=hp^.next^.next;
inc(newhp^.size,hp^.next^.size);
dispose(hp^.next);
hp^.next:=newhp;
end
else
begin
newhp^.next:=hp^.next;
hp^.next:=newhp;
end;
break;
end;
hp:=hp^.next;
end;
end;
end;
procedure ungetiftemp(const ref : treference);
var
tl,prev : pfreerecord;
begin
if istemp(ref) then
begin
prev:=nil;
tl:=templist;
while assigned(tl) do
begin
{ no release of persistant blocks this way!! }
if tl^.persistant then
if (ref.offset>=tl^.pos) and
(ref.offset<tl^.pos+tl^.size) then
begin
{$ifdef EXTDEBUG}
Comment(V_Debug,'temp '+
' at pos '+tostr(ref.offset)+ ' not released because persistant !');
{$endif}
exit;
end;
if (ref.offset=tl^.pos) then
begin
ungettemp(ref.offset,tl^.size);
{$ifdef TEMPDEBUG}
Comment(V_Debug,'temp managment : ungettemp()'+
' at pos '+tostr(tl^.pos)+ ' found !');
{$endif}
if assigned(prev) then
prev^.next:=tl^.next
else
templist:=tl^.next;
dispose(tl);
exit;
end
else
begin
prev:=tl;
tl:=tl^.next;
end;
end;
{$ifdef EXTDEBUG}
Comment(V_Warning,'Internal: temp managment problem : '+
'temp not found for release at offset '+tostr(ref.offset));
{$endIf}
end;
end;
begin
tmpfreelist:=nil;
templist:=nil;
end.
{
$Log$
Revision 1.1 1998-06-08 16:07:41 pierre
* temp_gen contains all temporary var functions
(processor independent)
}