Mehdi AMINI via llvm-dev
2019-Oct-21 18:34 UTC
[llvm-dev] [mlir] Re: "MLIR meets LLVM" Round-Table at the LLVM Dev Meeting
Hi all, As a reminder, the round-table will be Tuesday, Oct 22, 10:20-11:30, see here: http://llvm.org/devmtg/2019-10/#round Here is a potential list of all the topics I gathered from everyone, let me know if I missed anything. - Intro, practical aspect of the integration (repository, etc.) - Can we have a machine-readable definition of LLVM IR in LLVM itself: instructions, tracking changes, altering the semantics in the dialect wrt LLVM IR. We could reuse this for the MLIR LLVM Dialect. - Clang: would the static analyzer be a good candidate for a project to be playing with a MLIR Dialect? - Using MLIR for SCEV, VPLAN, etc. Isn’t SCEV an IR? - MIR: could/should it be reimplemented as a MLIR dialect? - What about Alive? (If Alive folks are around?) - Representing parallelism in MLIR - Heterogeneous compilation: this includes GPU of course, but also more exotic platforms / third-party accelerator: how to plug all this into a codegen story? - Using MLIR dialects as a testbed for proposed LLVM IR changes (there were proposals of tensor types for LLVM for example). - Using MLIR for loop optimization and other higher-level transformations, e.g. doing LLVM->Polly->MLIR Affine->LLVM.- Note also that at shortly after the round-table, at 12:05pm the talk about An MLIR Dialect for High-Level Optimization of Fortran <https://llvm.org/devmtg/2019-10/talk-abstracts.html#tech19> will take place. Best, -- Mehdi On Fri, Oct 18, 2019 at 7:21 AM 'James Molloy' via MLIR <mlir at tensorflow.org> wrote:> > Some existing bits in LLVM that could have used MLIR are ScalarEvolution > expressions, VPlan, SelectionDAG. Moving these would be a lot of work > obviously but what are some new things under development that could use > MLIR from day one? > > I'd add to this list the MIR format, which is clearly crying out for > MLIR-ification. > > On Fri, 18 Oct 2019 at 14:00, Lei Zhang <antiagainst at google.com> wrote: > >> FYI: related to GPU compilation, there will also be a "Challenges using >> LLVM for GPU compilation" roundtable covering >> >> - Canonicalization vs. GPUs: Type mutation; >> - Control flow mutation (graphics shaders are more sensitive to this); >> - Divergence/reconvergence sensitivity; >> - Address-space awareness; >> >> Time slot hasn't been finalized but preliminary planned for Tue 3-4pm or >> Wed 2-3pm. >> >> http://lists.llvm.org/pipermail/llvm-dev/2019-October/136033.html >> >> Thanks, >> Lei >> >> >> On Tue, Oct 15, 2019 at 12:01 PM Sanjoy Das <sanjoy at google.com> wrote: >> >>> I won't be present during the round table, but it might be interesting >>> to discuss if there are ways to use MLIR within LLVM. >>> >>> Some existing bits in LLVM that could have used MLIR are ScalarEvolution >>> expressions, VPlan, SelectionDAG. Moving these would be a lot of work >>> obviously but what are some new things under development that could use >>> MLIR from day one? >>> >>> -- Sanjoy >>> >>> On Tue, Oct 15, 2019 at 3:59 AM 'Alex Zinenko' via MLIR < >>> mlir at tensorflow.org> wrote: >>> >>>> I would be interested in practical aspects: >>>> - practical connection between MLIR's LLVM dialect and actual LLVM IR: >>>> having a machine-readable definition of instructions, tracking changes, >>>> altering the semantics in the dialect wrt LLVM IR; >>>> - using MLIR dialects as a testbed for proposed LLVM IR changes (there >>>> were proposals of tensor types for LLVM for example). >>>> >>>> This may be partially orthogonal, but may be interesting: >>>> - using MLIR for loop optimization and other higher-level >>>> transformations, e.g. doing LLVM->Polly->MLIR Affine->LLVM. >>>> >>>> >>>> On Tue, Oct 15, 2019 at 1:27 AM Mehdi Amini <aminim at google.com> wrote: >>>> >>>>> Hey all, >>>>> >>>>> FYI the round-table will be Tuesday, Oct 22, 10:20-11:30, see here: >>>>> http://llvm.org/devmtg/2019-10/#round >>>>> >>>>> It would be nice to have an agenda now, what are your thoughts on >>>>> topics we should cover? >>>>> >>>>> Cheers, >>>>> >>>>> -- >>>>> Mehdi >>>>> >>>>> >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20191021/d50b7ee1/attachment.html>
Vedant Kumar via llvm-dev
2019-Oct-21 18:44 UTC
[llvm-dev] [mlir] Re: "MLIR meets LLVM" Round-Table at the LLVM Dev Meeting
> On Oct 21, 2019, at 11:34 AM, Mehdi AMINI via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hi all, > > As a reminder, the round-table will be Tuesday, Oct 22, 10:20-11:30, see here: http://llvm.org/devmtg/2019-10/#round <http://llvm.org/devmtg/2019-10/#round> > > Here is a potential list of all the topics I gathered from everyone, let me know if I missed anything. > > - Intro, practical aspect of the integration (repository, etc.) > - Can we have a machine-readable definition of LLVM IR in LLVM itself: instructions, tracking changes, altering the semantics in the dialect wrt LLVM IR. We could reuse this for the MLIR LLVM Dialect.The need for a machine-readable description of LLVM IR in LLVM itself has come up in past discussions re: the function merging pass. When LLVM IR is extended, it would be great if the function comparator utility automatically learned which IR properties to diff instead of silently miscompiling. vedant> - Clang: would the static analyzer be a good candidate for a project to be playing with a MLIR Dialect? > - Using MLIR for SCEV, VPLAN, etc. Isn’t SCEV an IR? > - MIR: could/should it be reimplemented as a MLIR dialect? > - What about Alive? (If Alive folks are around?) > - Representing parallelism in MLIR > - Heterogeneous compilation: this includes GPU of course, but also more exotic platforms / third-party accelerator: how to plug all this into a codegen story? > - Using MLIR dialects as a testbed for proposed LLVM IR changes (there were proposals of tensor types for LLVM for example). > - Using MLIR for loop optimization and other higher-level transformations, e.g. doing LLVM->Polly->MLIR Affine->LLVM.- > > Note also that at shortly after the round-table, at 12:05pm the talk about An MLIR Dialect for High-Level Optimization of Fortran <https://llvm.org/devmtg/2019-10/talk-abstracts.html#tech19> will take place. > > Best, > > -- > Mehdi > > > On Fri, Oct 18, 2019 at 7:21 AM 'James Molloy' via MLIR <mlir at tensorflow.org <mailto:mlir at tensorflow.org>> wrote: > > Some existing bits in LLVM that could have used MLIR are ScalarEvolution expressions, VPlan, SelectionDAG. Moving these would be a lot of work obviously but what are some new things under development that could use MLIR from day one? > > I'd add to this list the MIR format, which is clearly crying out for MLIR-ification. > > On Fri, 18 Oct 2019 at 14:00, Lei Zhang <antiagainst at google.com <mailto:antiagainst at google.com>> wrote: > FYI: related to GPU compilation, there will also be a "Challenges using LLVM for GPU compilation" roundtable covering > > - Canonicalization vs. GPUs: Type mutation; > - Control flow mutation (graphics shaders are more sensitive to this); > - Divergence/reconvergence sensitivity; > - Address-space awareness; > > Time slot hasn't been finalized but preliminary planned for Tue 3-4pm or Wed 2-3pm. > > http://lists.llvm.org/pipermail/llvm-dev/2019-October/136033.html <http://lists.llvm.org/pipermail/llvm-dev/2019-October/136033.html> > > Thanks, > Lei > > > On Tue, Oct 15, 2019 at 12:01 PM Sanjoy Das <sanjoy at google.com <mailto:sanjoy at google.com>> wrote: > I won't be present during the round table, but it might be interesting to discuss if there are ways to use MLIR within LLVM. > > Some existing bits in LLVM that could have used MLIR are ScalarEvolution expressions, VPlan, SelectionDAG. Moving these would be a lot of work obviously but what are some new things under development that could use MLIR from day one? > > -- Sanjoy > > On Tue, Oct 15, 2019 at 3:59 AM 'Alex Zinenko' via MLIR <mlir at tensorflow.org <mailto:mlir at tensorflow.org>> wrote: > I would be interested in practical aspects: > - practical connection between MLIR's LLVM dialect and actual LLVM IR: having a machine-readable definition of instructions, tracking changes, altering the semantics in the dialect wrt LLVM IR; > - using MLIR dialects as a testbed for proposed LLVM IR changes (there were proposals of tensor types for LLVM for example). > > This may be partially orthogonal, but may be interesting: > - using MLIR for loop optimization and other higher-level transformations, e.g. doing LLVM->Polly->MLIR Affine->LLVM. > > > On Tue, Oct 15, 2019 at 1:27 AM Mehdi Amini <aminim at google.com <mailto:aminim at google.com>> wrote: > Hey all, > > FYI the round-table will be Tuesday, Oct 22, 10:20-11:30, see here: http://llvm.org/devmtg/2019-10/#round <http://llvm.org/devmtg/2019-10/#round> > > It would be nice to have an agenda now, what are your thoughts on topics we should cover? > > Cheers, > > -- > Mehdi > > > > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20191021/1fcbb10b/attachment.html>