kernels: add 8i_x2_saturated_sum_8i

[evilynux]

Includes implementations for AVX2, SSE2 and NEON along the generic kernel. Beware, the NEON kernel is untested (don't have the HW handy).

[marcusmueller]

pinging @evilynux here: You still up for fixing this code in a spare minute?

[noc0lour]

@evilynux are you still interested in getting the changes merged?

[evilynux]

@noc0lour My apologies, I'm completely overwhelmed and have been unable to find the required time to fix this. I don't see this changing any time soon... :-/

[noc0lour]

No problem, let's see if I can look at this anytime soon. Thanks for your work until now!

[noc0lour]

@evilynux otherwise can you hit [email protected] an email to do a quick CLA so I can pick your work up in a spare minute?

[jdemel]

@evilynux Is there any update on the CLA?

[jdemel]

@evilynux I assume there's still no update on your CLA?

Anyways, we adopted a new system: DCO. Thus, you only need to sign off your commits. git commit -s for new commits. The details are explained in DCO.txt. With git commit -s you add a Signed off by ... line to the end of your commit message. You can add

I got this approach to sign previous commits from stackoverflow

git rebase --exec 'git commit --amend --no-edit -n -s' -i HEAD~1

I updated the option -s to lower case. Also, HEAD~1 should refer to your one commit. It would be great if you could rebase your PR onto current master. If you could fix the review comments, then we could merge this PR. I'd be happy to finally be able to do so.