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126 lines
4.1 KiB
ObjectPascal
126 lines
4.1 KiB
ObjectPascal
{
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Copyright (c) 1998-2002 by Jonas Maebe
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This unit calls the optimization procedures to optimize the assembler
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code for i386+
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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****************************************************************************
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}
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Unit aopt386;
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{$i fpcdefs.inc}
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Interface
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Uses
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aasmbase,aasmtai,aasmdata,aasmcpu;
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Procedure Optimize(AsmL: TAsmList);
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Implementation
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Uses
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globtype,
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globals,
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DAOpt386,POpt386,CSOpt386;
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Procedure Optimize(AsmL: TAsmList);
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Var
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BlockStart, BlockEnd, HP: Tai;
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pass: longint;
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slowopt, changed, lastLoop: boolean;
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Begin
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slowopt := (cs_opt_level3 in current_settings.optimizerswitches);
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pass := 0;
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changed := false;
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dfa := TDFAObj.create(asml);
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repeat
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lastLoop :=
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not(slowopt) or
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(not changed and (pass > 2)) or
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{ prevent endless loops }
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(pass = 4);
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changed := false;
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{ Setup labeltable, always necessary }
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blockstart := tai(asml.first);
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blockend := dfa.pass_1(blockstart);
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{ Blockend now either contains an ait_marker with Kind = mark_AsmBlockStart, }
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{ or nil }
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While Assigned(BlockStart) Do
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Begin
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if (cs_opt_peephole in current_settings.optimizerswitches) then
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begin
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if (pass = 0) then
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PrePeepHoleOpts(AsmL, BlockStart, BlockEnd);
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{ Peephole optimizations }
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PeepHoleOptPass1(AsmL, BlockStart, BlockEnd);
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{ Only perform them twice in the first pass }
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if pass = 0 then
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PeepHoleOptPass1(AsmL, BlockStart, BlockEnd);
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end;
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{ Data flow analyzer }
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If (cs_opt_asmcse in current_settings.optimizerswitches) Then
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begin
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if dfa.pass_generate_code then
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{ common subexpression elimination }
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changed := CSE(asmL, blockStart, blockEnd, pass) or changed;
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end;
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{ More peephole optimizations }
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if (cs_opt_peephole in current_settings.optimizerswitches) then
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begin
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PeepHoleOptPass2(AsmL, BlockStart, BlockEnd);
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if lastLoop then
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PostPeepHoleOpts(AsmL, BlockStart, BlockEnd);
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end;
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{ Free memory }
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dfa.clear;
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{ Continue where we left off, BlockEnd is either the start of an }
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{ assembler block or nil }
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BlockStart := BlockEnd;
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While Assigned(BlockStart) And
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(BlockStart.typ = ait_Marker) And
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(Tai_Marker(BlockStart).Kind = mark_AsmBlockStart) Do
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Begin
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{ We stopped at an assembler block, so skip it }
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Repeat
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BlockStart := Tai(BlockStart.Next);
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Until (BlockStart.Typ = Ait_Marker) And
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(Tai_Marker(Blockstart).Kind = mark_AsmBlockEnd);
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{ Blockstart now contains a Tai_marker(mark_AsmBlockEnd) }
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If GetNextInstruction(BlockStart, HP) And
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((HP.typ <> ait_Marker) Or
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(Tai_Marker(HP).Kind <> mark_AsmBlockStart)) Then
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{ There is no assembler block anymore after the current one, so }
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{ optimize the next block of "normal" instructions }
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BlockEnd := dfa.pass_1(blockstart)
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{ Otherwise, skip the next assembler block }
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else
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blockStart := hp;
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End;
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End;
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inc(pass);
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until lastLoop;
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dfa.free;
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End;
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End.
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