Flang Biweekly Sync - Notes from the June 10, 2020 call

Flang team,

Here are the notes from the June 10, 2020 Flang biweekly call.

The next Flang Technical Community will be Monday, June 15, 8:30 AM Pacific time. We will be discussing the RFC for refactoring front-end support for Clang and LLVM for Flang.

The next Flang biweekly call will be Wednesday, June 24, 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


  • International Fortran Conference
  • LLVM Technical Call topic
  • Classic Flang pull request process update
  • LLVM Flang development update


  • International Fortran Conference

  • Ondřej Čertík (LFortran) and NVIDIA (Flang) have submitted abstracts. No word on acceptance yet.

  • Flang Community Technical Biweekly Call

  • Next topic: Outstanding reviews. Discuss the RFC for driver refactoring between LLVM and Clang to support a full Flang driver.

  • The last call was June 1. Craig Rasmussen and Kate Rasmussen discussed 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.

  • 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 (GCC 9.3). They added another to build with Clang 8.

  • NERSC and Argonne National Lab are working to set up buildbots as well. NERSC buildbot is in progress still.

  • Andzrej Warzynski and Carol Concatto continue to work on the flang driver. Discussions continue on refactoring clang driver and LLVM utilities to better support multiple front ends.

  • Continued work on semantic checking for TYPE (F2018 Clause 7). 63 of 115 checks are completed.

  • Committee code for lowering I/O statement branching and loops in I/O data lists.

  • Finished refactoring callee/caller interface lowering into a single utility based on the existing Fortran subprogram characteristics framework.

  • Continued work on compiling all DATA statement initializations, including accounting for EQUIVALENCE and COMMON. This should wrap up this week.

  • Continued work on MLIR and FIR in f18-llvm-project. Continued to push small commits to llvm-project for the fairly large amount of code that needs to be merged.

  • Original Flang Dev news and updates

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

  • We will be publishing an 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.

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