Re: [PATCH newlib]New configuration option disable io vector buffer in Newlib

[Corinna Vinschen <vinschen at redhat dot com>]

On Mar 27 17:22, Bin Cheng wrote:
> > > Thanks for suggestions. As for the changes:
> > > For code size, this patch reduces about 2+KB text section with below
> > > command line for a simple formatted IO program:
> > > $ arm-none-eabi-gcc -mthumb -mcpu=cortex-m0 -Os -ffcuntion-sections
> > > -fdata-sections -Wl,--gc-sections -lc -lnosys -lc main.c -o main.exe
> > >
> > > The library itself is build with "-Os -ffunction-sections -fdata-sections".
> > >
> > > For performance, I measured a formatted IO test which calls lots of
> > > "snprintf" and runs for about 10Secs. Turns out this patch can improve
> > > performance about 5~6%, but I won't claim how good the patch is
> > > because it's just one use-case.
> > >
> > > As for how-to document, I am not sure how to handle it. There are a
> > > bunch of "--disable/enable-*" options, but neither HOWTO nor README mentions
> > them.
> > > Maybe we could re-factor the document and find a place to describe
> > > these options in detail.
> > 
> > Yes, that's a bummer.  I think we could really need somebody who would be
> > willing to add all these options to the README file with a bit of explanation
> > what each of them is doing.
> > 
> 
> I did investigation on how those options work before, maybe I can take this work later. I have some other patches to reduce code size, I can get back to this once I finish them.

That would be incredibly helpful.  Thanks for the offer!


Corinna

-- 
Corinna Vinschen
Cygwin Maintainer
Red Hat