LLVM Weekly - #648, June 1st 2026

Welcome to the six hundred and forty-eighth 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.

The Call for Workshops for the 2026 LLVM Developers' Meeting is out. Deadline June 3rd.

The next Compiler Social Zurich will take place on June 17th with a talk from Hendrik Klug from Synthara.

The next Cambridge (UK) Compiler Social will take place on Thursday 4th June at the Computer Laboratory and feature a talk from Lana Josipović, “From Software Programs to Digital Circuits”. Be sure to sign up if you can attend.

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

Office hours with the following hosts: Quentin Colombet, Johannes Doerfert, Renato Golin.
Online sync-ups on the following topics: formal specification, MLIR C/C++ frontend, pointer authentication, MemorySSA, Clang static analysis, OpenMP, Clang C and C++ language working group, Flang, SPIR-V, RISC-V, LLVM libc, HLSL, LLVM qualification, MLGO, LLVM libc math.
For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.

The LLVM security response group 2025 transparency report is now available.
Ian McCormack is looking for feedback on a proposal to add a BorrowSanitizer, for finding violations of Rust’s Tree Borrows aliasing model in LLVM.
Aaron Ballman shared the text of the submission to ISO on open access to standards documents.
Tue Ly provided an update on quad precision support in LLVM.
Madhur Amilkanthwar suggests modularising SLPVectorizer.cpp.
Sergey Shcherbinin posted an RFC on adding a univeral profile-guided automatic software loop data prefetcher to LLVM.
“imperatormk” posted an RFC on adding an Apple Metal/AIR backend target to LLVM, which would lower LLVM IR to a loadable .metallib for Apple Silicon GPUs.
Mishal Shah is planning to add pre-merge testing on macOS and is seeking feedback from the community and infra team.
The RFC on enforcing the rule of three has been updated with a poll.
Jeff Bailey started an RFC discussion on cleaning up LLVM libc entrypoints.
Aiden Grossman would like to remove the lit external shell now there are no upstream users and downstream users are starting to migrate off.
Marc-André Lureau proposed supporting more documentation styles in clang-doc.

Initial MC layer support was added for RISC-V RVY (CHERI). 098b05f.
LLVM’s DenseMap performance was improved, replacing tombstone deletion with a different algorithm. c4d820c.
musttail with indirect arguments was fixed on LoongArch. 19e915f.
Call frame information was implemented for AMDGPU non-kernel functions. f78a233.
llvm-debuginfo-analyzer gained the ability to take LLVM IR input. 6bbbf74. REVERTED
The DW_AT_LLVM_language_dialect DWARF attribute was added, with the intend of differentiating the source programming language from the programming model (e.g. CUDA/SIMT, Tile, etc). c09041a, 6c9542c.
MC layer support was added for the experimental RISC-V Zvdota (batched dot product). d25ec4b.
llvm-objdump and llvm-readobj can now dump Windows x64 Unwind v3 information. e1e52c9.
-fstack-clash-protection support was added for LoongArch. 5cac275.
Work started to factor out common parts of the SiFive RISC-V scheduling models, to reduce duplication. b76d08a.
The documentation on writing IR test cases was improved. f857294.
TableGen now has a !switch operator to conditionally use a value based on exact key match. 025b9a2.

-fno-debug-record-sysroot will exclude the absolute path to the sysroot from debug info, to aid reproducible builds. 85717da.
__builtin_clear_padding was introduced. 698d44b.
The ghlink Sphinx plugin used for Clang documentation was rewritten. 0ed795a.
You can use the experimental constant interpreter by default by setting the CLANG_USE_EXPERIMENTAL_CONST_INTERP CMake option. 08d281f.
clang-doc now supports a non-pretty JSON serialisation, resulting in smaller output vs the pretty-printed one. 92cfd0a.

DEC Alpha support was added to libsanitizer. 992ee59.
Minimal support for PGO was added for HIP offload. 5db1364.
LLD gained the necessary support for the cooperative multithreading defined in the WebAssembly Component Model. 577e9a7.
Initial infrastructure was added to LLDB for a plugin for debugging hardware accelerators like GPUs. 3d24f9a.