Flang Biweekly Sync - Notes from the May 27, 2020 call

Subprojects Flang
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Flang team,

Here are the notes from the May 27th, 2020 Flang biweekly call.

There will be a special Flang LLVM technical call on alias analysis Thursday, May 28th at 7:00 AM Pacific time.

The next Flang Technical Community will be Monday, June 1st, 8:30 AM Pacific time.

The next Flang biweekly call will be Wednesday, June 10th, 2020 at 8:30 AM Pacific time.

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

  • Follow-on meeting to discuss LLVM alias analysis tomorrow
  • International Fortran Conference
  • LLVM Flang development update

Highlights

  • Alias analysis teleconference

  • The follow-on call for LLVM alias analysis is Thursday, May 28th at 7:00 AM PDT. The goal is to get ideas on interim next steps and longer-term items.

  • Meeting URL: https://bluejeans.com/643493129?src=join_info

  • Tarique Islam of IBM recommends some resources to review before the call. These are listed below.

  • International Fortran Conference

  • Ondřej Čertík (LFortran) and NVIDIA (Flang) have submitted abstracts.

  • Deadline for abstracts is June 1.

  • LLVM Flang update

  • Arm stood up a flang buildbot for Arm AArch64 at lab.llvm.org - see http://lab.llvm.org:8011/builders/flang-aarch64-ubuntu. They plan to add another.

  • NERSC and ANL are working to set up buildbots as well.

  • Arm’s submission regarding OpenMP IR will be submitted to LLVM soon.

  • Patch submitted for throwaway driver to handle libraries better.

  • Flang/clang LLVM driver refactoring work continues; working on an RFC to describe refactoring to llvm/Frontend.

  • New implementation for constraints Clause 7 (Type) C741-C750 reviewed and merged.

  • Continued work on lowering for I/O statement branching and loops in I/O data lists.

  • Refactoring callee/caller interface lowering into a single utility based on Fortran subprogram characteristics.

  • Implemented most of the lowering for DATA statements. Worked on compiling all DATA statement initializations for each symbol and converting to a single initialization constant for lowering. Still work to do on pointer initialization and equivalenced variables.

  • Worked on runtime support for allocatables and finalization.

  • Original Flang Dev news and updates

  • We’ve pushed a simple change to the stage branch of flang.

  • Is a binary release planned? None has been done recently, but it hasn’t seemed like a priority from the community.

  • Flang Community Technical Biweekly Call

  • The last call was Monday, May 18th. We discussed the current status of flang and some places where people can look to contribute.

  • The next technical call is scheduled for June 1. Craig Rasmussen and Kate Rasmussen will discuss experience with source-to-source translation using flang.

  • Hal Finkel encourages people to 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.

**Details (**Updates below are in bold)

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We pushed one pull requests to the stage branch. Continuing to work on a

process for proposals, testing, approvals and merge.

[…]

Nick Romero asked about any upcoming binary release. None has been done

recently. It hasn’t seemed like a priority from the community. NVIDIA can

do one at any time.

What is the latest status on the process for proposals, testing, approvals

and merge? Huawei is interested in an updated release of classic Flang,

preferably one based on LLVM 10, and would like to help if possible.

Has anyone worked on porting classic Flang to LLVM 10? I have ported the

patches to LLVM 10, and I am wondering if it is something that the community

would be interested in. However, I can’t just submit a pull request as there

currently isn’t a monorepo-based repo for classic Flang.

Thanks!

Bryan

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> From: flang-dev <flang-dev-bounces@lists.llvm.org> On Behalf Of Bryan Chan via flang-dev
> Subject: Re: [flang-dev] Flang Biweekly Sync - Notes from the May 27, 2020 call

We pushed one pull requests to the stage branch. Continuing to work on a

process for proposals, testing, approvals and merge.

[…]

Nick Romero asked about any upcoming binary release. None has been done

recently. It hasn’t seemed like a priority from the community. NVIDIA can

do one at any time.

What is the latest status on the process for proposals, testing, approvals

and merge? Huawei is interested in an updated release of classic Flang,

preferably one based on LLVM 10, and would like to help if possible.

I’m working on some build scripts that Would be of general use in Flang.

Once I have those validated and running in our Jenkins environment here,

we will be steadily streaming changes back into current Flang. I’ll be

documenting the process on the wiki as well.

I believe the folks at Arm have made sure that classic flang is up to date

with LLVM 9.

Has anyone worked on porting classic Flang to LLVM 10? I have ported the

patches to LLVM 10, and I am wondering if it is something that the community

would be interested in. However, I can’t just submit a pull request as there

currently isn’t a monorepo-based repo for classic Flang.

The community would definitely be interested in this. I believe there are changes

to flang-compiler/flang-driver and flang-compiler/llvm that might need to be pulled

forward as well. Are you referring to that? Or pull requests into flang itself for LLVM 10?

Let me know if you have other questions.

Thanks!

Gary