[llvm-dev] [RFC] AAP Backend

[Renato Golin via llvm-dev]

On 18 August 2016 at 08:34, Ed Jones via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> We believe the code base is sufficiently mature that it is appropriate
> for inclusion. Currently, the full source for AAP can be found on Github:
> https://github.com/embecosm

Hi Ed,

I had a look at the GitHub project and it wasn't clear what is needed
to move the AAP target in-tree.

First, it seems you're merging our tree into yours, which means the
merge commit [1,2] show the differences between old and new LLVM
stuff, not yours vs. upstream. This makes it hard to predict the
affected changes.

Also, you seem to have a standard-looking lib/Target/AAP [3], which is
a good step forward, but you also have added the simulator [4] in
there, which is not the right place. This should probably be a
different project altogether.

So, from our recent check-list for new targets, I'm assuming a few things:

Code owner: You?
Community: Embecosm + its users
License: AFAICS, check.
Docs / Impl: check

The thing that isn't clear right now is "compatible code and policies".

I don't see why we shouldn't take the AAP target, unless it poses a
big enough change to IR, the middle end, etc. So, I recommend two
steps:

1. A quick summary of the target independent changes you had to do to
make your back-end work. Changes to IR semantics, additional Clang
checks, base classes overwritten, etc.

2. Propose some patches on Phabricator, showing those differences.
These patches don't need to be the whole thing, for now, but basic
support ("hello world" style) should be working and tested.

We can continue from there.

cheers,
--renato


[1] https://github.com/embecosm/aap-llvm/commit/1d767ab10d0de413c341fe69ca228b97e7e1d255
[2] https://github.com/embecosm/aap-clang/commit/d1c2e5081a6222f2b4ab8d175fbd68a5e803c6d9
[3] https://github.com/embecosm/aap-llvm/tree/aap-master/lib/Target/AAP
[4] https://github.com/embecosm/aap-llvm/tree/aap-master/lib/Target/AAPSimulator