Hi,
A minimal MSEgui program compiled with FPC 2.6.0 is 711KB on i386-win32 and 796KB on i386-linux.

I tried to optimize it with "Whole Program Optimization". On win32 I get:
"
Free Pascal Compiler version 2.6.0 [2011/12/25] for i386 Copyright (c) 1993-2011 by Florian Klaempfl and others Target OS: Win32 for i386
Compiling minimal.pas
[...]
Compiling main.pas
Compiling main_mfm.pas
Linking minimal.exe
minimal.pas(12,1) Error: Error during reading symbol liveness information produced by "E:\FPC\2.6.0\bin\i386-win32\objdump.exe -t " minimal.pas(12,1) Fatal: There were 1 errors compiling module, stopping Fatal: Compilation aborted
"
minimal.pas is
"
program minimal;
{$ifdef FPC}{$mode objfpc}{$h+}{$endif}
{$ifdef FPC}
{$ifdef mswindows}{$apptype gui}{$endif}
{$endif}
uses
{$ifdef FPC}{$ifdef linux}cthreads,{$endif}{$endif} msegui,mseforms,main;
begin
application.createform(tmainfo,mainfo);
application.run;
end.
"
^(12,1)

On Linux compiling works, there is a binary of 1.3MB after third run as described in
http://wiki.freepascal.org/Whole_Program_Optimization#Concrete_example After "strip -s" the size is 780KB.

Running the program crashes at startup with
"
An unhandled exception occurred at $080A1045 :
EAbstractError : Abstract method called
$080A1045
$0809B6F5
$0809AD8B
$080AF2AA
$080AEFC0
$080AE4D2
$0806FB92
$0805C884
$0804E48A
$0805FE70
$0804DF94
$0804DCFD
$0804DB2D

An unhandled exception occurred at $0804C2DF :
An unhandled exception occurred at $B7CE9B7A :
"
Should whole program optimization work with FPC 2.6.0?

Martin

From http://wiki.freepascal.org/Whole_Program_Optimization#Limitations_4 :

"This optimisation requires that the nm utility is installed on the system. For Linux binaries, objdump will also work."

On Linux compiling works, there is a binary of 1.3MB after third run as described in http://wiki.freepascal.org/Whole_Program_Optimization#Concrete_example After "strip -s" the size is 780KB.

On my Linux/i386 system it's 133kb after strip -s, and 261kb before. Have you recompiled the 2.6.0 rtl somehow?

Strange. This example is tested every night in the test suite runs and works fine there on Linux/i386: http://www.freepascal.org/testsuite/cgi-bin/testsuite.cgi?action=3&run1id=108780&testfileid=3122 . I've also just tested it on Linux/i386 (see above) and it works fine for me.

Should whole program optimization work with FPC 2.6.0?

Yes. The FPC 2.6.0 compiler binary itself is even compiled with whole program optimizations (although not with the symbol liveness information switch, because that requires smart linking and for historical reasons that's not enabled for the binaries we release).

Jonas

Jonas Maebe wrote

On my Linux/i386 system it's 133kb after strip -s, and 261kb before. Have you recompiled the 2.6.0 rtl somehow?

If I recompile the RTL with Stabs or DWARF debug information, the binary becomes 606kb resp. 564kb before stripping, but still 133kb after. And it also continues to work.

Jonas

Jonas Maebe wrote

From http://wiki.freepascal.org/Whole_Program_Optimization#Limitations_4 : "This optimisation requires that the nm utility is installed on the system. For Linux binaries, objdump will also work."

I've fixed the compiler so it no longer tries to use objdump if the target OS is different from Linux.

Jonas

Thanks, where can I get that "nm utility" for win32?

The result is wit the MSEgui minimal program not the testprogram in the Wiki, sorry for confusion.

It is the MSEgui minimal program not the example.

Then I should try without symbol liveness information too?

Martin

Martin Schreiber wrote

Thanks, where can I get that "nm utility" for win32?

Any distribution of the GNU binutils for win32 should include it. I don't have Windows myself, but I suppose the mingw site would be a good place to look for it.

It is the MSEgui minimal program not the example.

Then that looks like a bug in the optimization (unless you e.g. use pointer hacks to directly read the addresses of virtual methods from the VMT, in which case there is nothing the compiler can do about this).

The crash you posted means that a virtual method is getting called while the compiler/optimizer thought that it could never be called from the program.

Then I should try without symbol liveness information too?

You can try, yes. It shouldn't make a difference, but you never know.

Jonas

Thanks. The normally 711KB MSEgui win32 minimal program is 694KB after strip with -OWall/-Owall. There is an symbolliveness it is 697KB, there is an EAbstractError too.

AFAIK there is no direct VMT access in MSEgui. I assume gdb debugging with symbolinfo is not possible after whole program optimization? gdb shows:
"
(gdb) run
Starting program: /home/mse/proj/msegui/testcase/mse/minimal/minimal [Thread debugging using libthread_db enabled]
An unhandled exception occurred at $08075595 :
EAbstractError : Abstract method called
$08075595 line 1875 of main.pas
$08070455 line 1875 of main.pas
$0806FA7B line 1875 of main.pas
$080F4389 TWIDGET__HASOVERLAPPINGSIBLINGS, line 8588 of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/msegui.pas $08087711 LOADMODULE, line 1974
of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/mseclasses.pas $080867EC DOLOAD, line 2499
of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/mseclasses.pas $0808663E INITMSECOMPONENT, line 2521
of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/mseclasses.pas $0808504A LOADMSEMODULE, line 2636
of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/mseclasses.pas $080A15D0 TMSEDATAMODULE__CREATE, line 136
of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/msedatamodules.pas $080A77F4 INIT, line 293
of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/msestockobjects.pas $0807BC64 INIT, line 1661
of /home/mse/packs/standard/git/mseide-msegui/lib/common/graphics/msegraphics.pas $0805EC5F TGUIAPPLICATION__INTERNALINITIALIZE, line 16396 of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/msegui.pas $08082AF1 TCUSTOMAPPLICATION__INITIALIZE, line 1615 of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/mseapplication.pas $08081FD3 TCUSTOMAPPLICATION__CREATE, line 1046
of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/mseapplication.pas $0804E23F TGUIAPPLICATION__CREATE, line 16387
of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/msegui.pas $0804DF36 TINTERNALAPPLICATION__CREATE, line 14518 of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/msegui.pas $0804DD25 APPLICATION, line 3423
of /home/mse/packs/standard/git/mseide-msegui/lib/common/kernel/msegui.pas "
main.pas has 16 lines only, hasoverlappingsiblings is never called in minimal program.

Martin

Martin Schreiber wrote

AFAIK there is no direct VMT access in MSEgui. I assume gdb debugging with symbolinfo is not possible after whole program optimization?

It should be no problem, only a few call instructions point to different places and some VMT entries are set to FPC_ABSTRACTERROR afterwards. However, debug information and smart linking don't work together very well.

Jonas

.
.

I guess that we should add nm.exe to our releases for Win32, Win64, GO32v2 and possibly also OS/2 then...

Tomas

Martin Schreiber wrote

Hi, A minimal MSEgui program compiled with FPC 2.6.0 is 711KB on i386-win32 and 796KB on i386-linux.

BTW, the same MSEgui minimal program compiled with Delphi 7 has an exe size of 571KB.

Martin

I'am on the way for them already.

Alright, I added nm.exe to SVN for GO32v2 (from the same binutils version 2.17 as used for the other tools; there's also a DJGPP build of binutils 2.21 but that would probably require some testing first and I couldn't do that).

BTW, should we go to that version in the future, we need to add GPL version 3 license to our SVN tree in addition to the other license files (GPL3 is explicitly referenced in the version information).

Tomas

I made MSEgit Delphi compatible too:

FPC 2.6.0: 1.92MB
Delphi 7: 1.61MB

Martin

08.04.2012 11:33, Martin Schreiber пишет:

You might want to compare with FPC 2.7.1 after revision 20119, it is expected to generate smaller code for string and other managed type operations. For Lazarus executable I got about 10% total size decrease.

Regards,
Sergei

I can not use FPC 2.7.1 for the testcase because of cpstrnew, sorry.

Martin

Martin Schreiber wrote

Thanks. The normally 711KB MSEgui win32 minimal program is 694KB after strip with -OWall/-Owall. There is an EAbstractError at startup. Without symbolliveness it is 697KB, there is an EAbstractError too.

The problem was that interface methods that map to virtual methods weren't taken into account. It's fixed in trunk.

Jonas

Thanks! :-)
Will the fix be backported to fixes_2_6?

Martin

Yes, in a week or so.

Jonas

Jonas Maebe wrote on Sat, 21 Apr 2012:

I merged it to the fixes branch last weekend.

Jonas