LLVM Weekly - #663, September 14th 2026
Welcome to the six hundred and sixty-third issue of LLVM Weekly, a weekly newsletter (published every Monday) covering developments in LLVM, Clang, and related projects. LLVM Weekly is brought to you by Alex Bradbury. Subscribe to future issues at https://llvmweekly.org and pass it on to anyone else you think may be interested. Please send any tips or feedback via email: asb@asbradbury.org, or Mastodon: @llvmweekly@fosstodon.org / @asb@fosstodon.org, or Bluesky: @llvmweekly.org / @asbradbury.org.
News and articles from around the web and events
Dominic Stöcker wrote on the LLVM blog about their GSoC project to extend Clang API notes for C++ with overload-specific annotations for functions and methods.
The next Portland area LLVM social will take place on September 17th.
The next Compiler Social Zurich will take place on October 14th.
According to the LLVM Calendar in the coming week there will be the following:
- Office hours with the following hosts: Clang maintainers, Alexey Bader, Phoebe Wang, Johannes Doerfert.
- Online sync-ups on the following topics: Flang, MLIR C/C++ frontend working group, lifetime safety + interop, vectorizer, massive binaries, modules, lifetime safety, LLVM/Offload, Clang C and C++ language working group, OpenMP for flang, HLSL, reflection.
- For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.
On the forums
Renato Golin, Adam Siemieniuk, and Tuomas Karna shared an update on MLIR Project Lighthouse.
The 77th MLIR News is now available.
Andrew Haberlandt posted an RFC proposing a stable report format for sanitizers.
Andy Kaylor shared that he’s currently working on LLVM ABI library support for AARch64, pointing to PRs under review.
LLVM 23.1.1 was released.
Yaxun (Sam) Liu proposed adding block.uniformity.profile and branch.uniformity.profile LLVM IR metadata kinds.
Leonardo Román Carrillo started an RFC discussion on adding a per-function code model attribute. Arthur Eubanks provided more background.
Wenlong Mu is interested in enabling post-link optimisation with BOLT for stripped ELF binaries.
Jacob Hodgson would like to extend llvm-profgen to generate LLVM sample proflies directly from bsic perf events containing sampled instruction pointers.
LLVM commits
preferZeroCompareBrannch was enabled for X86. 59c5d5e.
LoopInterchange now supports partially-perfect loop nests. 821ff7c.
LoongArch gained a memory barrier optimisation pass. c9a1fc8.
llvm.loop.alignmetadata was documented. cebfe6c.The
thread-modelmodule flag was introduced. e17b8cb.
Clang commits
-fkeep-inline-functionswas implemented which causes function definitions to be emitted even if they have been inlined into all their callers. 28efe19.Clang now generates its diagnostics reference as Markdown. 9f52468.
ClangIR handling of the dynamic exception specification was documented. f471750e.