large G++ locale overhead in g++ 4.9.2 (was: Re: 25% PowerPC code size increase since last September?)

Peter Dufault dufault at hda.com
Mon Jun 29 13:20:05 UTC 2015


> On Jun 28, 2015, at 11:53 , Joel Sherrill <Joel.Sherrill at oarcorp.com> wrote:
> 
>> There are also a bunch of new shell commands that are pulling in new
>> code, that might be a lot of the rest.
> 
> This can be configured down.
> 
> But overall, you may want to try per element data and function sections on the compile and link. See the SPARC bsps for a reference. They had quite a bit of code removed in the tests building with those options. But you have to get the linker script right for things to still work. Sections need an asterisk to wild card the per method/data item sections. 
> 
> And you may have to mark some sections as KEEP. Or they won't have a dependency to get them in.

By only including the RTEMS shell commands I use I reduced the size to 1839664 (latest RTEMS) vs 1624684 (September RTEMS), about a 13% increase, but at least it fits in FLASH.

The overhead appears to be mostly all the locale “stuff” in g++ 4.9.2 vs g++ 4.8.2.  I did some googling but don’t see how to reduce this, does anyone know of a way?  I really don’t need currency customization.

Peter
-----------------
Peter Dufault
HD Associates, Inc.      Software and System Engineering



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