Re: [arm-gnu] Huge Code Size CodeSourcery G++ Lite

[David Brown <david@xxxxxxxxxxxxxxx>]

On 01/07/2011 03:42, Senel Murat (CR/RTC4.1-NA) wrote:
> Hi;
> Recently, I tried building a project on Cortex-M3 using the CodeSourcery
> G++ Lite. However, the size of the binary becomes huge.
> As a comparison to a commercial toolchain, here is the difference of the
> .bin for a simple "blink" application:
> Commercial IDE: 4.6KB
> Eclipse IDE with CodeSourcery G++ Lite: 14.3KB
> Any ideas? Is this normal, or are we making some stupid mistakes?
> Thanks,
> -Murat

Without more information, it's only possible to make vague guesses.  My 
guess here is that you are using C++, with exceptions and RTTI enabled, 
and have ended up linking in substantial parts of the library to deal 
with unhandled exceptions, etc.  If that's the case, have a look at the 
recent "Tons of seemly extraneous code linked in c++ program" thread in 
this list.

Alternative likely causes are using printf or related functions, and 
ending up with a lot of the maths library.

Have a look at a detailed map file to see what's being included, and why.


Note that if these library functions are actually useful somewhere in 
your real program, then they will be linked in anyway.  It's a on-off 
code cost - the extra 10K library space will use 10K whether your 
program is 4K or 400K, and the same (roughly) applies to other 
toolchains.  Code size comparisons are only really relevant if you look 
at an entire real-world program, or if you consider just the size of the 
object file for a particular code file you are interested in.