LLVM Weekly - #634, February 23rd 2026

Welcome to the six hundred and thirty-fourth 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

It’s the last week for EuroLLVM early bird pricing, ending by 1st March. Additionally, more mentors are still being sought.

The first virtual Women in Compilers and Tools meetup of the year is confirmed for March 14th. Jyothi Vedurada will present “Compiler Optimizations for CPU-GPU Heterogeneous Systems”.

Chris Lattner blogged about the recent Claude C Compiler experiment and what we can learn from it.

If you’re interested in the next Cambridge UK LLVM social, be sure to fill out the poll for potential time/dates.

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

• Office hours with the following hosts: Kristof Beyls, Johannes Doerfert, Amara Emerson.
• Online sync-ups on the following topics: formal specification, ClangIR upstreaming, LLVM pointer authentication, OpenMP, Flang, SPIR-V, RISC-V, embedded toolchains, HLSL, LLVM libc math.
• For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.

On the forums

• Minutes from the October, November, and December LLVM Foundation board meetings have been posted.

• Shafik Yaghmour proposed adding a precommit clang-tidy check for the rule of three. Some discussion was about whether the rule of five would be better.

• Balazs Benics asked which doc format is preferred in LLVM (reStructuredText, Markdown, inline Doxygen). So far the conclusion is that .rst is the standard for docs in the docs/ subdirectory for now, and moves to use .md for the maintainers file don’t represent a change from that. Someone could post an RFC proposing such a change of course.

• Caroline Newcombe proposed adding conditional expression support to Flang.

• Kevin McAfee posted an RFC on adding per-function option attributes e.g. gvn.enable-pre for the enable-pre option for the gvn pass. Respondents so far are not keen on exposing such flags en masse in this way.

• Walter Erquinigo started a discussion on upstreaming basic support in LLDB for accelerators.

• Matt Arsenault is ready to remove bugpoint, now llvm-reduce should be a complete replacement.

• Rahul Joshi is looking to shorten long register/sub-register index names. There’s strong support and some links to proof of concept PRs in the thread, as well as the wonderfully unwieldy example RISC-V sub-register index sub_vrm1_1_sub_vrm1_2_sub_vrm1_3_sub_vrm1_4_sub_vrm1_5_sub_vrm1_6_sub_vrm1_7.

LLVM commits

• Scalar loads were marked as rematerialisable on SystemZ. 7c1d517.

• automerge can now be enabled in the git-llvm-push script. 63db233.

• The data dependence graph .dot graph output has colour now! ca16347.

• AMDGPULibCalls learned to expand pow/power/pown/rootn for floats with fast math enabled. 3b5ed86.

• A new m_Value overload was added to SDPatternMatch to conditionally bind the value matching a sub-pattern. e022ea2.

• The ‘llubi’ UB-aware IR interpreter upstreaming continued with support for GEP/alloca/inttoptr. 63492ca.

• A target-independent rematerialisation helper was added. 3239246.

• As part of the effort to support Lightweight Fault Isolation (LFI), the MCLFIRewriter was upstreamed. f6c86bd.

• Initial infrastructure was added for compiling LLVM with PCH (precompiled headers), starting with LLVMSupport. b82c7fc.

• The target-specific HexagonGlobalScheduler pass was added, implementing global instruction scheduling and other optimisations. 7064ff2.

• The new prefalign attribute can be used to mark a function’s preferred alignment. 943504e.

Clang commits

• JSON serialisation and deserialisation support was added for Clang’s Scalable Static Analysis Framework (SSAF). 7c3c9c4.

• The default -mtune for macOS is now apple-m5. 3d3ad01.

• Overflow behaviour types was added as a new Clang extension allowing control (via annotations) of overflow behaviour for integer times. 7f631bb.

• The pointer field protection mitigation against use after free was implemented. 370d7ce.

• A TableGen backend was added for generating documentation for builtins. 1aaa338.

Other project commits

• TSan grew support for ‘adaptive delay scheduling’, which improves race detection by perturbing thread schedules. a591a44.

• An ACCDeclareActionConversion pass was added to Flang as part of OpenACC support. ddffc04.

• Basic support was added to flang-rt for I/O from OpenMP GPU offloading. 21b3461, 70b5a1d.

• Target-specific relocation scanning was implemented for AArch64 and some other targets in LLD, as part of a refactoring. 371e0e2, c04b00d.

• Tree-sitter based syntax highlighting was added to LLDB. Tree-sitter based Swift and Rust syntax highlighting was added using this framework. f03ff95, 4a4ab28, b453adf.

• A large refactoring was done on MLIR’s structured control flow (SCF) dialect ParallelLoopFusion pass. c5ae550.

• OpenMP standalone build mode was removed, the runtimes build should be used instead. 6295b8e.