fpc/compiler/i386/aopt386.pas
2003-02-26 21:15:43 +00:00

138 lines
4.4 KiB
ObjectPascal

{
$Id$
Copyright (c) 1998-2002 by Jonas Maebe
This unit calls the optimization procedures to optimize the assembler
code 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 aopt386;
{$i fpcdefs.inc}
Interface
Uses
aasmbase,aasmtai,aasmcpu;
Procedure Optimize(AsmL: TAasmOutput);
Implementation
Uses
globtype,
globals,
DAOpt386,POpt386,CSOpt386;
Procedure Optimize(AsmL: TAAsmOutput);
Var
BlockStart, BlockEnd, HP: Tai;
pass: longint;
slowopt, changed, lastLoop: boolean;
Begin
slowopt := (cs_slowoptimize in aktglobalswitches);
pass := 0;
changed := false;
repeat
lastLoop :=
not(slowopt) or
(not changed and (pass > 2)) or
{ prevent endless loops }
(pass = 4);
changed := false;
{ Setup labeltable, always necessary }
BlockStart := Tai(AsmL.First);
BlockEnd := DFAPass1(AsmL, BlockStart);
{ Blockend now either contains an ait_marker with Kind = AsmBlockStart, }
{ or nil }
While Assigned(BlockStart) Do
Begin
if pass = 0 then
PrePeepHoleOpts(AsmL, BlockStart, BlockEnd);
{ Peephole optimizations }
PeepHoleOptPass1(AsmL, BlockStart, BlockEnd);
{ Only perform them twice in the first pass }
if pass = 0 then
PeepHoleOptPass1(AsmL, BlockStart, BlockEnd);
{ Data flow analyzer }
If (cs_fastoptimize in aktglobalswitches) Then
begin
If DFAPass2(
{$ifdef statedebug}
AsmL,
{$endif statedebug}
BlockStart, BlockEnd) Then
{ common subexpression elimination }
changed := CSE(asmL, blockStart, blockEnd, pass) or changed;
end;
{ More peephole optimizations }
PeepHoleOptPass2(AsmL, BlockStart, BlockEnd);
if lastLoop then
PostPeepHoleOpts(AsmL, BlockStart, BlockEnd);
{ Dispose labeltabel }
ShutDownDFA;
{ Continue where we left off, BlockEnd is either the start of an }
{ assembler block or nil }
BlockStart := BlockEnd;
While Assigned(BlockStart) And
(BlockStart.typ = ait_Marker) And
(Tai_Marker(BlockStart).Kind = AsmBlockStart) Do
Begin
{ We stopped at an assembler block, so skip it }
Repeat
BlockStart := Tai(BlockStart.Next);
Until (BlockStart.Typ = Ait_Marker) And
(Tai_Marker(Blockstart).Kind = AsmBlockEnd);
{ Blockstart now contains a Tai_marker(asmblockend) }
If GetNextInstruction(BlockStart, HP) And
((HP.typ <> ait_Marker) Or
(Tai_Marker(HP).Kind <> AsmBlockStart)) Then
{ There is no assembler block anymore after the current one, so }
{ optimize the next block of "normal" instructions }
BlockEnd := DFAPass1(AsmL, BlockStart)
{ Otherwise, skip the next assembler block }
Else BlockStart := HP;
End;
End;
inc(pass);
until lastLoop;
End;
End.
{
$Log$
Revision 1.8 2003-02-26 21:15:43 daniel
* Fixed the optimizer
Revision 1.7 2002/07/01 18:46:29 peter
* internal linker
* reorganized aasm layer
Revision 1.6 2002/05/18 13:34:21 peter
* readded missing revisions
Revision 1.5 2002/05/16 19:46:50 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
}