[SYCL][Matrix] Add spec document for the matrix extension interface and its first implementation for AMX

[dkhaldi]

Signed-off-by: Dounia dounia.khaldi@intel.com

[keryell]

That seems quite interesting.
It is not clear to me in which namespace they are defined.
Probably they could be defined as friend in the matrix class itself so the operations can be found by ADL, avoiding to type the namespace again and again everywhere...
It would be interesting to investigate whether providing also member functions would simplify the API.
Provide both so it is possible to use the best one for each use case, while waiting for https://en.wikipedia.org/wiki/Uniform_Function_Call_Syntax to land into C++?

[dkhaldi]

That seems quite interesting.
It is not clear to me in which namespace they are defined.

@keryell They are defined cl::sycl::ext::intel::matrix;
I will add the "using namespace cl::sycl::ext::intel::matrix;"
to the code example

Probably they could be defined as friend in the matrix class itself so the operations can be found by ADL, avoiding to retype the namespace everywhere...
It would be interesting to investigate whether providing also member functions would simplify the API.

They are free functions to match the group library algorithms. But I will add your comment to the open questions section.

[keryell]

I will add the "using namespace cl::sycl::ext::intel::matrix;"

On the long term, using either member functions or ADL could avoid this requirement that adds to the namespace clutter...

[dkhaldi]

ping @gmlueck

[gmlueck]

This is looking a lot better! Now that I understand the intent, I have some more comments.