Flang Biweekly Sync - Notes from July 24, 2019 call

Flang team,

Here are the notes from the July 24th, 2019 Flang biweekly call. Updates are in bold.

Please be sure to let us know if you have any questions and agenda topics for the next call.

The next Flang biweekly call will be August 7th, 2019 at 8:30 AM Pacific Time.

Thank you.

Gary Klimowicz


  • Flang Community Technical Call – Flang driver discussion
  • F18 development update
  • Flang development update


  • Supercomputing 2019

  • Hal submitted for an LLVM BoF session at SC 2019.

  • There won’t be an LLVM in HPC Workshop this year.

  • Flang Community Technical Biweekly Call

  • Hal Finkel is hosting this call on Bluejeans, Wednesdays 8:30 Pacific Time, the weeks alternating with this call. The notes for all these calls can be found in Google Docs here.

  • The July 17th call had Arm presenting a proposal for the new Flang driver program. There don’t appear to be any objections to the plan proposed.

  • The next call is scheduled for July 31st, 8:30 AM PDT. The scheduled agenda topic is the OpenMP.

  • F18 as an LLVM project

  • The LLVM-hosted flang-dev mailing list has been set up. Subscribe at https://lists.llvm.org/cgi-bin/mailman/listinfo/flang-dev.

  • We will continue to support the original flang-dev@lists.flang-compiler.org through August 2019.

  • The source code repository has not yet been set up in subversion, nor in the Monorepo.

  • Plan is still to upload documentation for F18 before the code, to help establish the project goals and design strategy before uploading the code. This should help establish context for the project.

  • F18 update

  • Implemented distinguishability checks for generic assignment and operators.

  • Working on allowing forward references to derived types in component definitions.

  • Worked on OpenMP parse tree node definitions and parsing to add more source provenance information.

  • Additional fixes for semantic issues identified by running internal test suites against f18.

  • Started implementing ANINT, FLOOR and CEILING scalar folding.

  • More work on MLIR based Fortran intermediate representation, refactoring to take into account potential high-level optimizations.

  • More work on DO loop semantics and constraint checking, including DO CONCURRENT locality specifications.

  • More work on OpenMP directive parsing and semantic checks.

  • We are close to the point where we will turn on semantic processing by default. This will make it easier for people to check existing codes against f18 and expanding the test suite in f18.

  • Flang Dev news and updates

  • More bug fixes in queue to send to Flang.

  • G0 edit descriptor support.

  • Support for long file names.

  • Improved Fortran debug metadata for formal parameters.

Where we can use your help

  • Subscribe to the new LLVM Flang email list: https://lists.llvm.org/cgi-bin/mailman/listinfo/flang-dev. We will be cross-posting to both flang-dev mailing lists until September.
  • Please provide any additional feedback to the RFC regarding the compiler driver submitted to flang-dev. The thread can be found in the cfe-dev email list here.
  • Please comment on the DEBUG metadata enhancement proposed for LLVM (CHARACTER intrinsic type). This is the last Flang debug metadata enhancement that has not been upstreamed to LLVM: https://reviews.llvm.org/D54114.
  • Topics for the next biweekly community call and technical community call.
  • Let us know if you have presentations or meetings relevant to the Flang community. We will publicize them in these notes.