[llvm-dev] Orc JIT v1 Deprecation
Stefan Gränitz via llvm-dev
llvm-dev at lists.llvm.org
Fri May 17 14:25:00 PDT 2019
On 5/17/19 9:46 PM, Christian Schafmeister wrote:
> I'm very excited about the work Lang has been doing
Yes, I completely agree! And I am sure everyone does. Without his work
Orc wouldn't exist and we wouldn't be anywhere close to it.
On 5/17/19 9:46 PM, Christian Schafmeister wrote:
> I thought I would add a data point.
>
> I implemented the Orc v1 API in Clasp - an implementation of Common
> Lisp that uses llvm as the backend.
> Recently, I switched over to using the new API - works great! I'm
> very excited about the work Lang has been doing and I'm excited to
> hear that there is a fix for lldb debugging of jitted code coming
> (thanks Stefan!).
>
> Orc v1 API Clasp: (https://github.com/clasp-developers/clasp/tree/dev)
> New Orc API Clasp:
> (https://github.com/clasp-developers/clasp/tree/dev-llvmtot)
>
> It's a bit weird because Clasp is self-hosting and I expose the llvm
> API's to Common Lisp and I use the llvm API's in a combination of C++
> code and Common Lisp code.
>
>
>
>
> On Fri, May 17, 2019 at 3:35 PM Stefan Gränitz
> <stefan.graenitz at gmail.com <mailto:stefan.graenitz at gmail.com>> wrote:
>
> I agree, the deprecation of Orc v1 should come with more guidance
> and preparation than currently available. I don't think you are
> missing any channel. The main sources of information are code and
> reviews. I gathered some data on typical lines of argumentation
> below. Maybe it makes sense to have look at them in isolation.
>
> TL;DR: While I do have a number of proposals for the points in the
> end, I would first like to hear your opinions.
>
> (1) MCJIT can be considered mature and stable, while Orc is
> experimental:
> * Orc is in trunk for more than 4 years now [1]
> * tutorials moved to Orc with Release 3.8 (3 years ago) [2]
> * "ORC should be preferred for new projects" made it to the
> official release notes only now, with 8.0
> * it's a common statement on the list since many years [3]
>
> (2) The LLVM test suite has various use-cases for lli, so the JIT
> gets exercised well. Grepping through lit tests on master today
> gives me:
> * 202 matches for lli in total (regex: RUN.*[% ]lli)
> * 80 matches for lli using Orc v1 (regex: RUN.*[%
> ]lli.*jit-kind=orc-mcjit)
> * 17 matches for lli using Orc v2 (regex: RUN.*[%
> ]lli.*jit-kind=orc-lazy)
>
> (3) There are few active stakeholders in LLVM JIT development:
> * ExecutionEngine saw about 250 commits in total during the last
> year (looking at: llvm/include/llvm/ExecutionEngine &&
> llvm/lib/ExecutionEngine)
> * 192 of these are from Lang, most of the remaining one's are
> either not touching the JIT or NFC
> * I just submitted a fix for JITed code debugging in LLDB, which
> was broken since Release 5.0 [4]
>
> Conclusions?
> * All newcomers go with Orc, because the tutorial uses it and the
> list recommends it.
> * Some newcomers became clients. Their projects got mature and
> they ask for a more stable API.
> * We saw drastic API changes in Orc with past releases. Upcoming
> releases should account for the rate of adoption more and more.
> * Most clients stay clients. Certainly, there are many reasons for
> that. Anyway, we need more active participation.
>
> It's time to:
> * Switch lli's default to Orc to increase visibility and test
> coverage. Of course, MCJIT-specific tests should pass -jit-kind=mcjit.
> * Agree on a way forward, at least for the current release, so we
> can carve out small/simple tasks and distribute the work in the
> community. If the removal of Orc v1 is part of the plan, we should
> start convergence soon.
> * Communicate/discuss the current state (haves and wants)
> regularly and transparently.
> * Get more people to participate actively.
>
>
> [1] https://github.com/llvm/llvm-project/commit/93de2a12
> [2]
> http://releases.llvm.org/3.8.0/docs/ReleaseNotes.html#non-comprehensive-list-of-changes-in-this-release
> [3] http://lists.llvm.org/pipermail/llvm-dev/2016-March/097767.html
> [4] https://reviews.llvm.org/D61611
>
> On 5/13/19 10:22 AM, Alex Denisov via llvm-dev wrote:
>> Hi folks,
>>
>> Rather by accident than on purpose I looked at the release notes and found the following:
>> http://releases.llvm.org/8.0.0/docs/ReleaseNotes.html#changes-to-the-jit-apis
>>
>> TL;DR: Orc v1 is deprecated and will be removed in the next release.
>>
>> I have several questions in this regard:
>>
>> 1. Is there a migration guide I can use to update my code to the new version?
>> 2. Is there any development plan for this part of LLVM? So far I have feeling that it's a closed source development.
>> 3. Is there some communication channels I am missing to follow? I follow dev&commits mailing lists and present on IRC once in a while, but I somehow missed the message about the Orc v1 removal.
>>
>> Also, the release notes mention that Orc v2 is the recommended way for the new projects, but:
>>
>> 1. Is there a documentation?
>> 2. How stable the APIs are?
>>
>> Thank you,
>> Alex.
>>
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
> --
> https://flowcrypt.com/pub/stefan.graenitz@gmail.com
>
>
>
> --
> Christian Schafmeister
> Professor, Chemistry Department
> Temple University
--
https://flowcrypt.com/pub/stefan.graenitz@gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20190517/f5d71be7/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: OpenPGP digital signature
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20190517/f5d71be7/attachment.sig>
More information about the llvm-dev
mailing list