Questions on the submission of new patch in the binutils

[Virendra Kumar Pathak <kumarvir dot pathak at gmail dot com>]

Hi Binutils Group,

We are working on a new armv8.1-a aarch64 based server processor.
We have a simple patch to introduce basic "-mcpu" flag for this
processor in the binutils, and thus are interested to upstream it.
Unfortunately, we do not have any prior experience in upstreaming &
working with binutils group.

Could you kindly help us by answering below questions. Or point me to
the appropriate links/documentation where such information is present.

[Questions]

1. What would be the appropriate branch to upstream this new patch? I
see there are three major active branches:  master, gdb-7.11-branch
and binutils-2_26-branch.
     [https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git]

2. What are the formal tests that needs to be done before proposing a
patch to binutils?

3. Due to active development in binutils, the development branches
move very fast.
    What if the branch, over which my patch is based, moves forward
after the submission of my patch for the review?
    Do I need to rebase it again?

Thanks in advance for your time and patience.

-- 
with regards,
Virendra Kumar Pathak