large G++ locale overhead in g++ 4.9.2

[Joel Sherrill]

On June 29, 2015 10:17:05 AM CDT, Peter Dufault <dufault at hda.com> wrote:
>
>> On Jun 29, 2015, at 10:38 , Joel Sherrill <Joel.Sherrill at oarcorp.com>
>wrote:
>> 
>> The -Map option to ld will show the dependency that pulled in each
>function or data element.. File level without those options.
>> 
>> It would be good to know what causes this all to get pulled in.
>
>I’ll try to get to this tonight.  I also would like to know what is
>pulling it in.
>
>> 
>>>> Your suggested flags makes a huge difference, it’s now 1424272
>bytes
>>> in size, at 12% decrease from September and a 22% decrease from
>>> building the application with gcc 4.9.2 without the flags. I don’t
>see
>>> as much locale stuff in there.  I only recompiled the user
>application
>>> code and not RTEMS itself.
>> 
>> Awesome! I thought it would help.
>
>When you did the work on the SPARC did you do everything, starting with
>the development environment build so that the libraries were also built
>that way?  Is that likely to be more difficult to do (you mentioned
>something about marking some sections as KEEP) versus the completely
>painless application rebuild that I just did?

I didn't touch the tools, just the SPARC bsp custom files. This really would benefit all bsps but it needs to be tested as it is done and that requires running some code on the hardware. So it will be slow moving it into bsps.

The KEEP had to be on sections like start, vectors, ctors, dtors, etc that are not directly referenced.

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

--joel