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Re: Contributing to glibc
- From: OndÅej BÃlka <neleai at seznam dot cz>
- To: Rogelio Serrano <rogelio dot serrano at gmail dot com>
- Cc: Bogdan Blidarescu <bogdan dot blidarescu at gmail dot com>, libc-alpha <libc-alpha at sourceware dot org>, Mihai Sarbulescu <mihai dot sarbulescu at gmail dot com>
- Date: Wed, 12 Nov 2014 15:17:00 +0100
- Subject: Re: Contributing to glibc
- Authentication-results: sourceware.org; auth=none
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On Tue, Nov 11, 2014 at 01:23:13AM +0000, Rogelio Serrano wrote:
> On Mon, Nov 10, 2014 at 10:49 PM, Bogdan Blidarescu
> <email@example.com> wrote:
> > Hello,
> > This is what I have found so far:
> > http://www.codeproject.com/Articles/4421/Henry-Spencer-s-Regexp-Engine-Revisited
> > ftp://ftp.freefriends.org/arnold/Awkstuff/
> > Cheers!
> Thanks Bogdan!
> I also did look at the glibc string function sources but its going to
> take a bit of reading assembler and disassembling test programs to
> understand how they work and why they are fast, or not.
That bit is out-of date for x64 I already optimized most of these so do
not expect much low hanging fruit. Improving these is hard, if you
profile applications you will find that 90% time is spend on strings
less than 64 bytes. I spend some time writing such headers. So you would need
to come with better header and check it improves applications.
You could look on another architectures or convert a x64 to i386
versions that should be relatively easy but time consuming.
> > On Tue, Nov 11, 2014 at 12:20 AM, Rogelio Serrano
> > <firstname.lastname@example.org> wrote:
> >> On Sun, Oct 26, 2014 at 3:30 PM, Bogdan Blidarescu
> >> <email@example.com> wrote:
> >> > Hello,
> >> >
> >> > We would like to contribute to the glibc library. Looking at the
> >> > PROJECTS file, this sounds interesting:
> >> >
> >> >
> >> >> [ 8] If you enjoy assembler programming (as I do --drepper :-) you
> >> >> might
> >> >> be interested in writing optimized versions for some functions.
> >> >> Especially the string handling functions can be optimized a lot.
> >> >> Take a look at
> >> >> Faster String Functions
> >> >> Henry Spencer, University of Toronto
> >> >> Usenix Winter '92, pp. 419--428
> >> Where can we find examples of the techniques described in the paper
> >> above? I can not find a copy anywhere and I would like to study and
> >> implement them.
> >> <snipped...>
> >> Thanks!
Party-bug in the Aloha protocol.