[Mesa-dev] [GSoC2016] Interested in implementing "Soft" double precision floating point support

[Emil Velikov]

Hello Elie,

On 9 March 2016 at 10:25, tournier.elie <tournier.elie at gmail.com> wrote:
> Hi everyone.
>
> My name is Elie TOURNIER, I am enrolled in a French Engineering school
> (Telecom Physique Strasbourg) specialized in Medical ICT.
> I'm interested in implementing "Soft" double precision floating point
> support [1].
> Taking this subject seem to be a good way to get my feet wet in the Mesa
> code and discover how some of its components works.
>
> I come to you in order to become know but also to retrieve valuable
> information for the success of this project.
>
> I would like to know more about the following things to understand your
> requirements :
> 1- "Each double precision value would be stored in a uvec2" The IEEE double
> precision floating point standard representation requires a 64 bit: 1 for
> sign, 11 for exponent and the others for fraction [2].
> -> How double precision value must be stored?
As one cannot assume the presence of doubles, one will need to return
the value as a two "unsigned" values. uvec2 the GLSL data type that
represents that. I believe one should at least basic understanding of
GLSL for this project.

https://www.opengl.org/wiki/Data_Type_(GLSL)

> 2- Where can I find GL_ARB_gpu_shader_fp64 documentation?
>
https://www.opengl.org/registry/specs/ARB/gpu_shader_fp64.txt

>
> This is my first exposure to Mesa. Please excuse me if I am asking basic
> questions.
>
> Please point me to the right resources so that I can better understand the
> project. I would also be happy to fix a bug to familiarize myself  with the
> source code. Any suggestions on bugs that are relevant to the project will
> be of great help.
>
First I would suggest that you rebuild mesa master based on your
distribution's recommended method. You should be comfortable doing
this and using the final package.

Skim though the git history, see if any of that make sense, is too
easy/hard, etc.

Past that you should demonstrate your ability to understand code,
using git and getting to know the procedure of creating patches,
submission and review. See http://mesa3d.org/devinfo.html for some of
the bits.

On the question of "what patches" - I would start with something easy.
>From resolving build warnings to tackling/skimming through the bugs
lists - depending on your hardware. I believe we ought to have a list
of simple contributions somewhere, but I cannot find it atm.

https://bugs.freedesktop.org/buglist.cgi?action=wrap&bug_status=NEW&component=Drivers%2FDRI%2Fnouveau
https://bugs.freedesktop.org/buglist.cgi?action=wrap&bug_status=NEW&component=Drivers%2FDRI%2Fi965

Last but not least, do come around in #dri-devel at FreeNode. Try to
get the feel what people are talking about and ping prospective
mentors.

I believe that's enough information to keep you busy for a bit, if not
do follow up. Be that here or on IRC.

Regards,
Emil