compiled program too big

compiled program too big

[Insanely Great]

Greetings

I am complete newbie to the world of programming.
Write my first console program which is around 11KB.
basically it takes a string as a first parameter and
does some stupid processing to it.

Works both in VC++ 6.0 in windows and gcc in RH Linux
7.2

The problem is when I comile with VC++ in Release mode
the output exe is 44KB.

when i comile the same program in linux using gcc -

gcc -O2 First.cpp

the resulting program is 126KB....why? am i missing
some option.

is there any option to tell gcc to compile it in
something like RELEASE MODE in VC++.

sorry for my ignorance and thanks in advance.

insane

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RE: compiled program too big

[Rupert Wood]

Insanely Great wrote: 

> The problem is when I comile with VC++ in Release mode the output
> exe is 44KB.
>
> when i comile the same program in linux using gcc -
> 
> gcc -O2 First.cpp
> 
> the resulting program is 126KB....why? am i missing some option.
> 
> is there any option to tell gcc to compile it in something like
> RELEASE MODE in VC++.

Hmm - you pretty much already are.

First up, comparing binary sizes between different compilers' default
options and different OSes is bogus. Some compilers (e.g. MSVC) default to
statically linking in C and C++ runtimes, automatically align pages at 4Kb
boundaries on disk for simpler cache management, single thread vs.
multi-thread-safe runtime, etc. (If people start complaining that MSVC makes
exes too big vs. gcc on linux I usually recommend they try flags '/MD /link
/align:16' to put them on a more equal footing - but that's usually because
the MSVC binaries are bigger!)

VC++'s release mode just means:

   1. use 'release' runtime, i.e. skip debugging checks in the
      runtime libraries for improved speed (and binary size
      if you're statically linking runtime); I don't think
      linux build environments have an equivalent to the debug
      runtime - that's easily switchable, at least

   2. optimize the code; -O2 is about equivalent to this

   3. don't include debug information in the binary; omitting
      -g from the GCC command line is equivalent to this.

so essentially you're already in release mode with your -O2. The other major
variable is the static / dynamic runtime library link; it's probably a
fairer comparison if you make sure both are linked against shared runtime
('-shared' in GCC, '/MD' on the VC++ command line, select DLL under Project
Settings, C++, Code Generation or similar in developer studio).

My final thought is that you've somehow not enabled dead code elimination in
GCC; thanks to the new, more strictly conforming templates in GCC this can
make a huge difference. I thought -O2 did enable DCE but you could try -O3
or check the manual to see if there's a specific switch - it's not one I've
used, sorry.

Good luck!
Rup.

Re: compiled program too big

[Mihnea Balta]

Try using this:

g++ -fno-exceptions -O2 First.cpp -Xlinker --strip-all

My results on a 2-line .cpp source:

[11:32am]/tmp# g++ -O2 test.cpp
[11:32am]/tmp# ls a.out
-rwxr-xr-x    1 root     root        11161 Jun 30 11:32 a.out
[11:32am]/tmp# g++ -fno-exceptions -O2 test.cpp -Xlinker --strip-all
[11:32am]/tmp# ls a.out
-rwxr-xr-x    1 root     root         2572 Jun 30 11:32 a.out

On Monday 30 June 2003 11:01, Insanely Great wrote:
> Greetings
>
> I am complete newbie to the world of programming.
> Write my first console program which is around 11KB.
> basically it takes a string as a first parameter and
> does some stupid processing to it.
>
> Works both in VC++ 6.0 in windows and gcc in RH Linux
> 7.2
>
> The problem is when I comile with VC++ in Release mode
> the output exe is 44KB.
>
> when i comile the same program in linux using gcc -
>
> gcc -O2 First.cpp
>
> the resulting program is 126KB....why? am i missing
> some option.
>
> is there any option to tell gcc to compile it in
> something like RELEASE MODE in VC++.
>
> sorry for my ignorance and thanks in advance.
>
> insane
>
> __________________________________
> Do you Yahoo!?
> SBC Yahoo! DSL - Now only $29.95 per month!
> http://sbc.yahoo.com
>
> ---------------------------------------------------------------------------
>-- Gaseste-ti perechea si castiga o saptamana la Poiana -
> http://dating.acasa.ro


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Re: compiled program too big

[Andrea 'fwyzard' Bocci]

At 01.01 30/06/2003 -0700, Insanely Great wrote:
>Greetings
>
>I am complete newbie to the world of programming.
>Write my first console program which is around 11KB.
>basically it takes a string as a first parameter and
>does some stupid processing to it.
>
>Works both in VC++ 6.0 in windows and gcc in RH Linux
>7.2
>
>The problem is when I comile with VC++ in Release mode
>the output exe is 44KB.
>
>when i comile the same program in linux using gcc -
>
>gcc -O2 First.cpp
>
>the resulting program is 126KB....why? am i missing
>some option.
>
>is there any option to tell gcc to compile it in
>something like RELEASE MODE in VC++.
>
>sorry for my ignorance and thanks in advance.
>
>insane

Try stripping the output executabled:

strip executable_file

This should remove all the sybols from the exe - it halved the size of a 
small test program in my cygwin environment, ven when no -g was specified 
on command line.

.fwyzard.