LLVM Weekly - #662, September 7th 2026
Welcome to the six hundred and sixty-second 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
The next LLVM/Clang social at Darmstadt will take place on September 30th and feature the talk “From Kotlin to IREE: Model as Code with MLIR and StableHLO” by Michal Harakal.
According to the LLVM Calendar in the coming week there will be the following:
- Office hours with the following hosts: Alina Sbirlea, Kristof Beyls.
- Online sync-ups on the following topics: formal specification, pointer authentication, qualification, OpenMP, Flang, RISC-V, LLVM embedded toolchains, HLSL, LLVM libc math library.
- For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.
On the forums
Reid Kleckner proposed a contributor policy refresh that would introduce a “reviewers” team (populated initially by the list of committers) separate to the “committers”. Tanya Lattner was concerned that the proposal may not encourage reviewers.
Nick Desaulniers started a discussion on adding an AGENTS.md file to the LLVM repository. There were a mix of responses, with some people concerned that it would be hard to have an AGENTS.md covering the full project or noting that LLMs can use existing documentation.
Erich Keane posted an RFC on enabling ClangIR in the Clang build by default. Of those who expressed concerns, a common one was the compile-time cost.
Anton Rapetov and Nemanja Rakovic propose the upstreaming of nanoMIPS support to LLVM.
Charitha Saumya wrote an MLIR RFC on tiling and fusing dependent reduction in linalg.
Renato Golin shared a MLIR PSA on the removal on linalg elementwise named operations.
Sameer Sahasrabuddhe sought clarity on the semantics of target extension types.
Aiden Grossman would like to delete the ExecutionEngine interpreter with any remaining users encouraged to migrate to llubi.
Alexis Engelke shared new numbers from work on compact unwind descriptors for x86-64.
Francesco Bertolaccini kicked off an RFC discussion on function-boundary zeroisation.
LLVM commits
LoongArch gained a late branch optimisation pass inspired by the equivalent RISC-V pass. 7300edd.
DirectX was promoted to an official backend! 1b0bd3a.
UniquingSetwas added, aFoldingSetwith typed keys. 937e353.The SPIRV backend gained support for DebugLexicalBlock. 7fc91d9.
llvm-profgen gained support for AArch64 BRBE branch profiles. 3993ccd.
-filter-print-source-locscan now be used to limit IR and machine-function dumps to matching debug locations, providing greater control when function filtering still prints too much with-print-after-all. 822f549, 657af0e.The X86 backend learned to lower i64 vector division and remainder through float division. 012428c5.
Clang commits
Loop interchange was enabled by default at O1 and above. e448a89.
User-facing documentation was added for the hardware-assisted AddressSanitizer. 4b5f595.
The old offloading driver was removed from Clang in favour of the ‘new’ one. feea42c.
A
modernize-use-to-underlyingcheck was added to clang-tidy. deb7382.