Hi Ed,
> On Aug 25, 2016, at 1:10 AM, Ed Jones via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
>
> As it stands, the active customers for this target are the out-of-tree
> backends which we are working on which can't be submitted for inclusion
> into LLVM.
>
I don’t feel you really answered Alex's question which was “can you
*quantify* the *active* customers for this target?”.
I understand that there are out-of-tree backends, but the question is about who
will use/develop/maintain this backend upstream in LLVM? And is there already
an open-source community around this backend somewhere?
I think Alex’s point is that there needs to be a sufficient user base or a
sufficient commitment of maintenance to warrant the burden of the backend on the
community.
—
Mehdi
> The general aim of the backend though is to include features from
> architectures which are not well represented in LLVM, for example
> non-power of two register sizes, non-octet chars, or very constrained
> register sets, and to this end we hope for it to be useful to the
> community at large if they are maintaining out-of-tree targets with
> features they would like LLVM to support.
>
> Thanks,
> Ed
>
> On 23/08/16 21:28, Alex Rosenberg wrote:
>> I don't think we've ever really built up clear guidance on
this, but I think there needs to be a clear determination that a given target
has enough active users to make the maintenance burden worth putting into the
mainline. In the past, the only exception I can think of is the Lanai backend,
but in that case we have a strong commitment of multiple employees at a major
corporation committed to that target's maintenance.
>>
>> So, concretely, can you quantify the active customers for this target?
>>
>> Alex
>>
>> On Aug 18, 2016, at 12:34 AM, Ed Jones via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
>>
>>> Hi all,
>>>
>>> We wish to submit our latest AAP implementation as an experimental
>>> backend into LLVM. We need community feedback and reviewers for
patches
>>> which we will submit soon.
>>>
>>> AAP was designed in early 2015 and aims to advance compiler
development
>>> for small deeply embedded Harvard architectures, which are widely
used
>>> commercially. AAP is freely available as an open source softcore
for use
>>> in FPGA designs.
>>>
>>> AAP has wide exposure: at ORCONF16 at CERN, at FOSDEM and at BCS
and
>>> OSHUG meetings. It is also of commercial interest, because of the
>>> potential benefits of providing upstream LLVM support for features
found
>>> in small embedded processors.
>>>
>>> Currently there is a complete Clang and LLVM toolchain including
gdb, ld
>>> and binutils, as well as two simulator implementations. The
toolchain is
>>> passing all LLVM regression tests and a decent proportion of GCC
>>> regression tests. We are also working on a GCC port to allow
comparison
>>> between compilers, which should be beneficial to both projects.
>>>
>>> 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
>>>
>>> Details about the ISA, and the hardware implementation can be found
on
>>> our website:
>>> http://www.embecosm.com/resources/appnotes/#EAN13
>>> http://www.embecosm.com/resources/appnotes/#EAN14
>>>
>>> We are also planning to talk about AAP at the LLVM Cauldron in
Hebden
>>> Bridge. We look forward to discussing our work on AAP with those
who are
>>> attending.
>>>
>>> Thank you,
>>> Ed Jones
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
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