LLVM Weekly - #617, October 27th 2025
Welcome to the six hundred and seventeenth 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
Matheus Izvekov blogged about recent changes to make the type representation in the Clang AST smaller.
Fangrui Song wrote a blog post about stack walking mechanisms, including the recently developed SFrame format.
The call for papers is now out for the ACM SIGPLAN 2026 International Conference on Compiler Construction (CC 2026).
According to the LLVM Calendar in the coming week there will be the following. Special note for this week: with the LLVM dev meeting going on some of these may be canceled but not yet marked as such on the calendar. Additionally, the European countries have exited daylight savings time over the weekend but the US won’t do so until next weekend, so times may be different to usual.
- Office hours with the following hosts: Johannes Doerfert.
- Online sync-ups on the following topics: Flang, modules, libc++, LLVM/Offload, SPIR-V, OpenMP for Flang.
- For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.
On the forums
Jan Korous posted an RFC on a scalable static analysis framework. This work from Apple comes from a prototype effort to implement a source code rewriting tool that uses static analysis methods to apply security hardening across C++ codebases.
Lucile Rose Nihlen announced the availability of a dashboard to monitor code review and contribution rates over time. The dashboard shows status such as LLVM commits per day, what percentage of these commits were landed without pre-commit review etc.
whitequark has an update on building LLVM for WebAssembly. A package is now available on NPM.
Nikita Popov proposed changing the indirectbr/blockaddress representation so that rather than having
blockaddressreferring to a basic block, to instead of it refer to a specificindirectbrsuccessor index.LLVM 21.1.4 was released.
Rahman Lavaee started an RFC discussion on adding support for inserting code prefetch instructions as a post-link optimisation step..
Petter Berntsson and the LLVM qualification group are collecting community input on the qualification of LLVM tools and libraries.
LLVM commits
A radix tree LLVM was added to LLVM’s datastructure library. 5fda2a5.
masked.{load,store,gather,scatter}now have alignment as an attribute on the pointer/vector pointers argument rather than as a separate immarg. 573ca36.The Hexagon backend gained a new optimisation pass for intermediate conversion instructions while performing vector floating point operations. e8b255d.
Initial support for a monotonicity check was added to DependenceAnalysis. ab789bef.
The unsafe-fp-math attribute was removed, now it is no longer used by any backends. d11b7bd, 76f15ea, 3656f6f2, 4f020c4.
Additional location tracking was added to the LLMV IR parser, in preparation for an LLVM IR LSP server. 18d4ba5.
Definitions were added for the Armv9.7-A architecture. 7ac2900, f28224b, 66e8270, f28224b, and more.
Clang commits
Clang started to emit
llvm.tbaa.errnometadata. efcda54.ClangIR try/catch statement support was upstreamed. d019a02.