[flang-commits] [flang] [flang] Add Flang Community Call notes for the August 12th meeting (PR #215853)

Wed Aug 12 12:00:17 PDT 2026

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+<!--===- docs/MeetingNotes/2026/2026-08-12.md
+
+   Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+   See https://llvm.org/LICENSE.txt for license information.
+   SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+-->
+# Community Call 2026-08-12
+
+## Agenda
+
+* Design docs and/or RFCs  
+  * [\[RFC\]\[flang\] Promote loop-invariant array-section reductions for vectorization](https://discourse.llvm.org/t/rfc-flang-promote-loop-invariant-array-section-reductions-for-vectorization/91499)  
+    * Feedback has been given and rework is necessary, will remove from the agenda for now until that rework is completed  
+  * [\[RFC\] \- Path Forward for \_FortranAAssignSimple Runtime Optimization](https://discourse.llvm.org/t/rfc-path-forward-for-fortranaassignsimple-runtime-optimization/91527)  
+    * Discussion ongoing on the Discourse post  
+  * [Perfectly-nesting fir.do\_loop nests (drop IV round-trip \+ sink final store): lowering or a pass?](https://discourse.llvm.org/t/perfectly-nesting-fir-do-loop-nests-drop-iv-round-trip-sink-final-store-lowering-or-a-pass/91532)  
+    * Discussion ongoing on the Discourse post  
+  *  [RFC: Add \`-finit-local=\` to Flang for Initializing Automatic Variables](https://discourse.llvm.org/t/rfc-add-finit-local-to-flang-for-initializing-automatic-variables/91545)    
+    * Flang does not currently have a way to handle initializing automatic variables, while most other compilers have some way to do this  
+    * This RFC seeks to add an option to fill the gap  
+    * The most common case is to initialize to zero, but there is another common case to initialize to a user-supplied special value, this RFC seeks to cover these most common cases in an easily maintainable way  
+    * Related existing PR (but only covers the initialization to zero case): [https://github.com/llvm/llvm-project/pull/159788](https://github.com/llvm/llvm-project/pull/159788)  
+      * Should coordinate with the author of this one  
+  * [\[RFC\]\[Flang\] Improving temporary and local array allocations \- unify StackArray/MemoryAllocation](https://discourse.llvm.org/t/rfc-flang-improving-temporary-and-local-array-allocations-unify-stackarray-memoryallocation/91353)	  
+    * 3 of 5 PRs in stack have been merged, these remain:  
+      * [\#210766 — \[flang\] Enable allocation-placement pass by default](https://github.com/llvm/llvm-project/pull/210766)  
+      * [\#210930 — \[flang\] Remove legacy stack-arrays and memory-allocation-opt passes](https://github.com/llvm/llvm-project/pull/210930)  
+    * Need to assess if there is a performance regression, there was at least one but it did not appear severe, Jean will investigate further when he returns from vacation  
+  * [\[RFC\] add support for collapsed io calls for implicit do loops](https://discourse.llvm.org/t/rfc-add-support-for-collapsed-io-calls-for-implicit-do-loops/91416)  
+    * Related PR: [https://github.com/llvm/llvm-project/pull/212646](https://github.com/llvm/llvm-project/pull/212646)   
+      * Needs more reviews  
+  * [\[RFC\]\[flang\] Add Floating-point trap handling support](https://discourse.llvm.org/t/rfc-flang-add-floating-point-trap-handling-support/90544)   
+    * Github issue has been closed: [https://github.com/llvm/llvm-project/issues/198657](https://github.com/llvm/llvm-project/issues/198657)   
+    * Related PR has been merged: [https://github.com/llvm/llvm-project/pull/208828](https://github.com/llvm/llvm-project/pull/208828)   
+    * will open more issues and related PRs for further IEEE arithmetic support (F2023 chapter 17\)  
+  * [\[RFC\] The Cost of Templates when Building Flang](https://discourse.llvm.org/t/rfc-the-cost-of-templates-when-building-flang/91197)  
+    * Related PR is now open for review: [https://github.com/llvm/llvm-project/pull/206907](https://github.com/llvm/llvm-project/pull/206907)  
+    * Please give input on the PR itself  
+  * [Choosing the default summation algorithm for Flang's SUM intrinsic](https://discourse.llvm.org/t/choosing-the-default-summation-algorithm-for-flangs-sum-intrinsic/91300)  
+    * Continuing discussion on the Discourse post  
+  * [\[RFC\] Support for \-std=f2023](https://discourse.llvm.org/t/rfc-support-for-std-f2023/89608)  
+    * New PR: [https://github.com/llvm/llvm-project/pull/205938](https://github.com/llvm/llvm-project/pull/205938)   
+    * Related Issue: [https://github.com/llvm/llvm-project/issues/196409](https://github.com/llvm/llvm-project/issues/196409)   
+    * **Reviews needed**, as the PR has been up for a few weeks already and there appears to not yet be consensus on the Discourse post  
+    * Current sticking points: concerns were expressed in the Discourse post, Chris Earl addressed them in the new PR but has not received specific feedback on them on the new PR  
+      * Using \-std=f2018 to change the warnings for SYSTEM\_CLOCK with the F2023 behavior becoming the default  
+      * Since this PR only adds warnings, not errors, it should not be considered a breaking change  
+      * Tarun will review again, then be sure to update the Discourse post and the PR  
+* PRs of Note  
+  * *Reviewers needed:*   
+    * PR 2 of 3 has been merged for a stack PR implementing rank-1 integer arrays with constant extent being used as explicit shape bounds.   
+    * PR 3 of 3: [https://github.com/llvm/llvm-project/pull/215403](https://github.com/llvm/llvm-project/pull/215403)   
+    * Associated llvm-test-suite PR: [https://github.com/llvm/llvm-test-suite/pull/411](https://github.com/llvm/llvm-test-suite/pull/411)   
+  * *Needs reviewers:* Avoid full source path in remarks: [https://github.com/llvm/llvm-project/pull/212669](https://github.com/llvm/llvm-project/pull/212669)   
+    * Related Discourse post: [https://discourse.llvm.org/t/flang-should-flang-remarks-include-the-full-path-to-the-source-file/91422](https://discourse.llvm.org/t/flang-should-flang-remarks-include-the-full-path-to-the-source-file/91422)   
+    * Awaiting review from people more familiar with the debug support  
+    * Vineet: this should be documented in Release Notes  
+  * *Feedback needed:* Unroll inner do loops when vectorization directive is present*:* [https://github.com/llvm/llvm-project/pull/210820](https://github.com/llvm/llvm-project/pull/210820)  
+* FYI   
+  * [LLVM23 rc3](https://github.com/llvm/llvm-project/releases/tag/llvmorg-23.1.0-rc3) dropped this morning  
+    * last chance for [flang release notes](https://github.com/llvm/llvm-project/blob/release/23.x/flang/docs/ReleaseNotes.md)
----------------
eugeneepshteyn wrote:

Starts lowercase where the other bullets are capitalized: `last chance` → `Last chance`.

https://github.com/llvm/llvm-project/pull/215853
