LLVM Weekly - #671, November 9th 2026

Welcome to the six hundred and seventy-first 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

Benedek Kaibás wrote on the LLVM project blog about their GSoC project to teach the Clang Static Analyzer to understand lifetime annotations.

Sukumar Sawant wrote on the LLVM project blog about their GSoC project to enable float80/float128 on unsupported targets for LLVM libc.

The next Toronto LLVM meetup will take place on 12th November. It will feature two presentations: “Getting started with LLVM (it’s not that scary!)” by Ayokunle Amodu and “From OpenMP to Offload: Lowering Safe Rust to GPUs” by Manuel Drehwald.

As a reminder, the call for presentations for the FOSDEM 2027 LLVM and MLIR devrooms closes on 22nd November.

According to the LLVM Calendar in the coming week there will be the following:

• Office hours with the following hosts: Alexey Bader, Clang maintainers.
• Online sync-ups on the following topics: Flang, LLVM qualification group, massive binary working group, modules, LLVM/Offload, BOLT, 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

• Reid Kleckner kicked off a debate on PR limits for non-committers, noting that limiting the number of open PRs for contributors without write access might be one way of rate limiting the incoming (often AI-assisted) PRs.

• Lewis Crawford started an RFC discussion about consistent denormal flushing during constant folding.

• Fangrui Song shared details of how LLVM library maintainers can help with the transition to declaring cl:: options in TableGen.

• Many more LLVM Dev Meeting roundtable or workshop notes have been posted: runtimes workshop, Flang round table, X86 roundtable, InstructionCost roundtable, SelectionDAG roundtable, LLVM libc roundtable, formal specifications round table, and loop transformations round table.

• Joseph Huber posted an RFC on adding a device address sanitizer for GPUs. DASan would provide fast low-overhead address sanitisation for AMD GPUs, avoiding the need for shadow memory.

• LLVM 23.1.5 was released.

• Aaron Ballman shared a summary from the recent discussion on library layering of Parser and Sema in Clang. In short: the status quo for the libraries will remain, but there will be a follow-up meeting to further discuss Sema using the Parser to generate AST nodes.

• Eli Friedman shared an update on the implementation status of LTO with linker scripts along with a link to the first PR up for review.

• Jeremy Morse is seeking feedback on plans to sunset the ‘old’ way of representing variable locations after instruction selection.

LLVM commits

• A ConcurrencySanitizer LLVM pass was added. c4c853f.

• The loop vectoriser gained support for tail folding vector epilogue loops. 541cafd.

• tracksRegLiveness was made true by default. 5294924.

• A SPIR-V target ABI classifier was added to the LLVM ABI library. 12e5222.

• -verify-machineinstrs was removed from MachineIR tests as llc now verifies the output by default. 2d7136e, 864850e.

• TableGen now caches instregex patterns to avoid repeated lookups. a68936f.

• MC layer support was added for the Zyhybrid RISC-V extension (part of CHERI support). 743905e1.

• A scheduling model was added for the Leon5 SPARC processor. 7517bcd.

Clang commits

• The -fsanitizer=concurrency option was introduced. 9ac8620.

• A BoundsSafety index page was added and the upstreaming status was documented. 4aaea35.

• A ClangIR pass was added to fold empty branches. a100bd4.

Other project commits

• A CheckedPtr wrapper around unique_ptr was added to LLVM’s libc. 8207e69.

• arm64e pointer authentication support was added to the MachO LLD linker. b1dc6f6.

• A MicrosoftABIRuntime was added to LLDB for resolving dynamic values in C++ on the Microsoft ABI. 08458ae.

• MemProf metadata is now supported in MLIR’s LLVM dialect. 4754186.