[flang-dev] Flang Biweekly Sync - Notes from the July 08, 2020 call
Gary Klimowicz via flang-dev
flang-dev at lists.llvm.org
Thu Jul 9 08:22:23 PDT 2020
Flang team,
Here are the notes from the July 8, 2020 Flang Community biweekly call.
The next Flang Technical Community will be Monday, July 13, 8:30 AM Pacific time.
The next Flang biweekly call will be Wednesday, July 22, 2020 at 8:30 AM Pacific time.
The next Classic Flang Technical biweekly call will be Wednesday, July 15, 2020 at 8:30 AM Pacific time. (This is a new open call for the original Flang.)
Information for joining these calls and the Slack channel is at the end of this email.
Let me know if you have any topics you would like covered in the next call.
Thank you.
Gary Klimowicz
Agenda
* ISC and LLVM Workshop on LLVM Compiler and Tools for HPC (recap)
* International Fortran Conference (recap)
* Classic Flang technical biweekly call
* LLVM Technical Call
* LLVM Flang development update
* Classic Flang update
Highlights
* LLVM Workshop on Compilers and Tools for HPC at ISC 2020 Digital
* June 25-26
* Talks by Kiran Chandramohan (Arm, OpenMP in MLIR and Flang<https://hps.vi4io.org/_media/events/2020/llvm-cth20_chandramohan.pdf>) and Will Lovett (ARM Scalable Vector Extension in LLVM<https://hps.vi4io.org/_media/events/2020/llvm-cth20_lovett.pdf>)
* Steve Scalpone (NVIDIA) talk on Compiling Three Generations of Fortran with LLVM (slides to come)
* International Fortran Conference 2020 Digital
* Steve Lionel keynote (mostly Fortran 2018)
* Lots of object-oriented Fortran (Arjen Markus's talk and the Saturday workshop he led with Tiziano Müller and Vladimir Rybkin was very good)
* Gary talked about Flang. Overall, Flang was well-received
* Many other talks that were of interest; web site is https://tcevents.chem.uzh.ch/event/12/. Presentations are recorded.
* Classic Flang biweekly call
* There Classic Flang biweekly call is now open to anyone (especially vendors) who are interested in using and improving Classic Flang.
* The call had been mostly for Classic Flang process and technical issues, hosted by Arm Ltd.
* It occurs at the same time as this call, the weeks this call is not held (Wednesdays, 8:30 AM Pacific time).
* Details for joining this call have been added to these call notes.
* Flang Community Technical Biweekly Call
* Next topic: Outstanding reviews. David Truby posted an RFC for LLVM 11; we will probably recap the outcome of this RFC.
* The last call was June 29. Discussed current status of lowering and upstreaming from fir-dev to llvm-project (56% (by volume) complete at the time).
* Please add both small and large technical topics to the Google Doc for the technical call. The link to the Google Doc can be found in the notes below.
* LLVM Flang updates
* Hal Finkel is working to identify a regular time every 4 weeks to continue the discussions on LLVM alias analysis. Next meeting information is in the details below.
* Andzrej Warzynski and Carol Concatto continue to work on the flang driver.
* Merged work on external I/O runtime.
* Continued work on ENTRY; subroutines pretty much done, but FUNCTION entries are tricky due to aliasing requirements on the result values.
* Implemented statement function lowering. Started work on internal function lowering.
* Completed work on passing intrinsics as function pointer actual arguments.
* Continued to merge work from the fir-dev fork of Flang into Flang proper, including lowering of I/O statements. About 60% of fir-dev is merged.
* Bug fixing from issues exposed by test suites, particularly FCVS.
* Began implementation of semantics for coarrays (specifying image selectors, NUM_IMAGES intrinsic).
* Improvements for parsing of OpenMP constructs.
* Original Flang Dev news and updates
* Kiran Chandramohan pushed PR#875 into Flang. This marks the first change pushed under the new Flang Community Pull Request process.
* We published the RFC to flang-dev on handling the outstanding pull requests for classic Flang. Arm, AMD and NVIDIA (others are welcome!) will be evaluating the pull requests for merge into the master branch. No significant feedback received on the RFC. Look in flang-dev for subject '[classic-flang]' if you're interested.
Details (Updates below are in bold)
1. Flang on GitHub
* LLVM Flang is merged with LLVM in https://github.com/llvm/llvm-project/tree/master/flang.
* There have been 2466 commits for LLVM Flang encompassing over 154,000 lines of code, documentation, CMakefiles and tests.
* There have been 1,677 total commits to Classic Flang in github.com/flang-compiler/flang.
* There are 534 people who have "starred" that flang repo and 80 forks.
1. Flang Community Technical Call (Hosted by Hal Finkel)
* The last call was June 29. Discussion centered on the status of lowering and the merge of the fir-dev branch into LLVM flang master branch.
* The LLVM alias analysis call is scheduled for Tuesday, July 14th 10:00 AM Pacific time (12-1 CDT, 6-7pm London). https://bluejeans.com/101176001?src=join_info. The agenda document is at https://docs.google.com/document/d/1ybwEKDVtIbhIhK50qYtwKsL50K-NvB6LfuBsfepBZ9Y/edit?usp=sharing
* The next call will be Monday, July 13, 8:30 AM PT.
* Outstanding reviews.
* LLVM 11 is coming; there is an RFC from David Truby about what we might do before the branch is made.
* Future Topics and tentative dates:
* Build times for the compiler.
* Please feel free to add agenda topics to the Google Doc: https://docs.google.com/document/d/1Z2U5UAtJ-Dag5wlMaLaW1KRmNgENNAYynJqLW2j2AZQ/
1. Flang community
* Website: www.flang-compiler.org<http://www.flang-compiler.org> redirects to http://github.com/flang-compiler/flang.
* Wiki: https://github.com/flang-compiler/flang/wiki is the Flang wiki page where the most up-to-date build instructions and news can be found.
* Issues:
* Bug reports for LLVM flang should be reported in Bugzilla: https://bugs.llvm.org/. Use the "flang" tag for flang-related issues, please.
* Bug reports for current Flang can be reported to https://github.com/flang-compiler/flang/issues.
* LLVM mailing lists: There are now two mailing lists hosted by llvm.org:
* The flang-dev mailing list has been set up. Subscribe at https://lists.llvm.org/cgi-bin/mailman/listinfo/flang-dev. These biweekly notes are now sent to this email list.
* The flang-commits mailing list has been set up. Subscribe at https://lists.llvm.org/cgi-bin/mailman/listinfo/flang-commits.
* Slack: flang-compiler.slack.com is used for informal real-time communication in the Flang community. The invitation link can be found at the end of this email.
* LLVM Workshop on Compilers and Tools for HPC at ISC 2020 Digital
* This was held June 25-26.
* Talks by Kiran Chandramohan (Arm, OpenMP in MLIR and Flang<https://hps.vi4io.org/_media/events/2020/llvm-cth20_chandramohan.pdf>) and Will Lovett (ARM Scalable Vector Extension in LLVM<https://hps.vi4io.org/_media/events/2020/llvm-cth20_lovett.pdf>)
* Steve Scalpone (NVIDIA) talk on Compiling Three Generations of Fortran with LLVM (flang/f18). This talk mostly focused on FIR code generation examples with a long example derived from Rajan Walia's work to convert FIR to the MLIR affine dialect so that loops in a Fortran array expression would be fused by existing MLIR optimizations.
* International Fortran Conference
* FortranCon 2020 was the first International Conference targeting the development for and with the Fortran programming language and took place on July 2 - 4 in Zurich, Switzerland. The web site is https://tcevents.chem.uzh.ch/event/12/.
* Gary Klimowicz (Flang) Thursday July 2, 9:20 AM PT.
* Ondřej Čertík (LFortran) Thursday July 2, 9:50 AM PT.
* Some interesting talks on object-oriented programming in Fortran, interfacing Fortran to other languages, and applications.
* Lots of people interested in modern Fortran, and promoting its use. About 250 people registered, and there were 100-150 attendees at most sessions.
1. What we're up to with the llvm-project/flang Fortran 2018 compiler
* On GitHub: The source code LLVM Flang is available on https://github.com/llvm/llvm-project/tree/master/flang. It's recommended to start in the "documentation" directory.
* Public plan: The team maintains a plan for upcoming Flang work at https://github.com/orgs/flang-compiler/projects/. This reflects current LLVM Flang priorities and context for the project and its long-term goals.
* Status: We continue development. Recent work includes:
* We had a good call last month on alias analysis in LLVM. Notes from the last call are available at https://docs.google.com/document/d/1ybwEKDVtIbhIhK50qYtwKsL50K-NvB6LfuBsfepBZ9Y/. Hal Finkel is working to identify a regular time every 4 weeks to continue the discussions. He has a Doodle poll at https://doodle.com/poll/9iqfaqttvvic5rfp to try to find the right time for this next meeting.
* Arm buildbots are set up at http://lab.llvm.org:8011/builders/flang-aarch64-ubuntu (GCC 9.3) and http://lab.llvm.org:8011/builders/flang-aarch64-ubuntu-clang (Clang 8).
* NERSC, LANL and Argonne National Lab are working to set up buildbots as well. NERSC buildbot is running, but failing; Brian Friesen is working through the issues. Argonne is working with ECP and security resources to negotiate whether they can set up their buildbot. LANL is facing the same uphill battle.
* Andzrej Warzynski and Carol Concatto continue to work on the flang driver.
* Continued work on ENTRY; subroutines pretty much done, but FUNCTION entries are tricky due to aliasing requirements on the result values.
* Work continued on external I/O runtime.
* Implemented statement function lowering. Started work on internal function lowering.
* Completed work on passing intrinsics as function pointer actual arguments.
* Continued to merge work from the fir-dev fork of Flang into Flang proper, including lowering of I/O statements. About 60% of fir-dev is merged.
* Bug fixing from issues exposed by test suites, particularly FCVS.
* Began implementation of semantics for coarrays (specifying image selectors, NUM_IMAGES intrinsic).
* Improvements for parsing of OpenMP constructs.
1. What we're up to with current Flang
* We sent an RFC to flang-dev on the handling of pull requests for merge into Flang. This will involve multiple parties contributing to the testing effort for the pull requests. Only one response (off-list) received. The process was adjusted to make it easier to work on multiple pull requests simultaneously. Look in flang-dev email for the subject '[classic-flang]' if you're interested in commenting.
* We use the Slack channel #classic-flang-pull-requests to coordinate what pull requests we are working on.
* Recent fixes pushed to Flang master
* #875<https://github.com/flang-compiler/flang/pull/875> Spelling fixes (a simple change)
* Outstanding pull requests: https://github.com/flang-compiler/flang/pulls for the current list of pull requests.
* Outstanding issues: Please refer to the Issues section on GitHub for flang-compiler/flang<https://github.com/flang-compiler/flang/issues> and flang-compiler/flang-driver<https://github.com/flang-compiler/clang/issues>.
* OpenMP 4.5 support:
o No update. OpenMP effort is now directed toward LLVM Flang.
* Debug Metadata:
* The outstanding review at https://reviews.llvm.org/D54114 [CHARACTER intrinsic data type] is stale and has been canceled. It will be replaced when there is an appropriate update for LLVM Flang.
* Packaging and Binary Releases:
* Spack: Spack packages for Flang have been updated. There is also a spack package for f18, based on the flang-compiler/f18 repository.
* Current Flang Fortran 2008 features
Current status of Fortran 2008 features can be found at https://github.com/flang-compiler/flang/wiki/Fortran-2008.
1. Logistics
Flang Community Biweekly Call (this call)
* General updates on the Flang project, both LLVM Flang and current Flang.
* Biweekly WebEx hosted by NVIDIA (which these notes cover).
* The meeting link for this biweekly call is https://nvmeet.webex.com/nvmeet/j.php?MTID=mb4edb8c799f69ec2dc0554acc969a162.
Note: If you are having difficulty connecting your audio, try using the "Call Me" option on WebEx to connect audio to your telephone.
Flang Slack Channel
* There is a Slack channel dedicated to Flang.
* Add yourself via the invitation link https://join.slack.com/t/flang-compiler/shared_invite/zt-2pcn51lh-VrRQL_YUOkxA_1CEfMGQhw
Flang Community Technical Biweekly Call
* Technical topics call.
* Hal Finkel hosts this call on Bluejeans<https://bluejeans.com/625064848>, Mondays 8:30 Pacific Time, on the weeks alternating with regular Flang biweekly call. The notes for all these calls can be found in Google Docs here<https://docs.google.com/document/d/1Z2U5UAtJ-Dag5wlMaLaW1KRmNgENNAYynJqLW2j2AZQ/>.
Meeting URL: https://bluejeans.com/625064848?src=join_info
Meeting ID: 625 064 848
Want to dial in from a phone? Dial one of the following numbers:
+1.408.317.9254 (US (San Jose))
+1.866.226.4650 (US Toll Free)
(see all numbers - https://www.bluejeans.com/premium-numbers)
Enter the meeting ID and passcode followed by #
Connecting from a room system?
Dial: bjn.vc or 199.48.152.152 and enter your meeting ID & passcode
Classic Flang Biweekly Technical Call
This is the sync call for people working with the original Flang project. The call happens every other Wednesday in the same week as the LLVM Flang Technical call (alternate week with the Flang Community Biweekly call).
The agenda is available here: https://docs.google.com/document/d/1-OuiKx4d7O6eLEJDBDKSRnSiUO2rgRR-c2Ga4AkrzOI.
Join the Microsoft Teams Meeting at https://teams.microsoft.com/l/meetup-join/19%3ameeting_YjM5YjlmNGEtMjA0MS00MTRlLTg5ZjUtOTM1ZGIxOTU2NWQy%40thread.v2<https://teams.microsoft.com/l/meetup-join/19%3ameeting_YjM5YjlmNGEtMjA0MS00MTRlLTg5ZjUtOTM1ZGIxOTU2NWQy%40thread.v2/0?context=%7b%22Tid%22%3a%22f34e5979-57d9-4aaa-ad4d-b122a662184d%22%2c%22Oid%22%3a%223641875c-ef5b-4767-8105-0787a195852f%22%7d>
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