LLVM Weekly - #628, January 12th 2026. 22.x branching tomorrow, LLVM: the bad parts, MLIR python bindings improvements, softPromoteHalfType default for backends, cross-compiling OpenCL libraries, and more llvmweekly.org/issue/628

Nikita Popov (who sadly isn't on Bluesky) has a great new post. LLVM: The bad parts www.npopov.com/2026/01/11/L...

LLVM Weekly - #627, January 5th 2026. Twelve years of LLVM Weekly, EuroLLVM CfP closing soon, GNU toolchain in 2025 summary, PCH to speed-up LLVM builds, LLVM ABI lowering library starting to land, and more llvmweekly.org/issue/627

LLVM Weekly - #626, December 29th 2025. Happy holidays! SFrame feedback, restrict progress, Nvidia Olympus AArch64 CPU scheduling model, libcxx rotate optimisations, and more. llvmweekly.org/issue/626

LLVM Weekly - #625, December 22nd 2025. FOSDEM LLVM dev room program, propeller profile conversion tool, AI tool policy, Arm C1 processors, Lightweight Fault Isolation upstreaming starts, and more llvmweekly.org/issue/625

LLVM Weekly - #624, December 15th 2025. Experience with [[clang:::musttail]], 2025 highlights for the MLIR vector dialect, -fdevirtualize-speculatively, closing the perf gap between RISC-V LLVM and GCC part 1, and more llvmweekly.org/issue/624

Does LLVM produce slower RISC-V code than GCC? Currently, yes. Can we make LLVM produce faster code? Also, yes! lukelau.me/2025/12/10/c... #llvm #riscv

LLVM Weekly - #623, December 8th 2025. EuroLLVM call for proposals, more US dev meeting videos, formal specification for LLVM IR working group, flow-sensitive nullability, LLVM RFC process norms documented, and more llvmweekly.org/issue/623

LLVM Weekly - #622, December 1st 2025. ClangIR upstreaming, advent of compiler optimisations, last chance to submit for the FOSDEM LLVM dev room, -gspilt-dwarf for RISC-V, and more llvmweekly.org/issue/622

We just extended the deadline for the #LLVM dev room at #FOSDEM submissions until 7th of December. There's still time to make your submission at pretalx.fosdem.org/fosdem-2026/... ! Full CFP at discourse.llvm.org/t/88746

LLVM Weekly - #621, November 24th 2025. Final call for FOSDEM LLVM devroom, US LLVM dev meeting videos starting to appear, minimum compiler requirements for building LLVM, naming address spaces, ORC design docs, and more llvmweekly.org/issue/621

LLVM Weekly - #620, November 17th 2025. EuroLLVM save the date, 'strong typedefs' in Clang, LLVM GC, MLIR minimum Python version, __builtin_bswapg, std::optional<T&>, and more llvmweekly.org/issue/620

LLVM Weekly - #619, November 10th 2025. DFAJumpThreading on by default for CoreMark perf boost, further CAS development, MLIR pygments lexer improvements, Arm contributions to LLVM 21, and more llvmweekly.org/issue/619

LLVM Weekly - #618, November 3rd 2025. Dev meeting roundtable notes, ABI lowering library blog post, Neoverse V3 scheduling model, Boost.Math imported, llvm.structured.gep, and more llvmweekly.org/issue/618

LLVM Weekly - #617, October 27th 2025. Clang AST optimisations, LLVM contribution rate dashboard, Clang/LLVM built for Wasm available on NPM, and more. For those able to make it, enjoy the LLVM Dev Meeting this week! llvmweekly.org/issue/617

LLVM Weekly - #616, October 20th 2025. Usability improvements to the Undefined Behavior Sanitizer, Clang bytecode interpreter developments, reducing process creation overhead for LLVM tests, null pointer arithmetic checker, and more llvmweekly.org/issue/616

LLVM Weekly - #615, October 13th 2025. Final call for 2025 US LLVM Dev Meeting registration, GNU Tools Cauldron 2025 videos posted, feedback on MLIR remarks, type punning through unions in C++, allocator partitioning hints, reproducible linker benchmarks with Nix, and more llvmweekly.org/issue/615

LLVM Weekly - #614, October 6th 2025. Revising LLVM's AI tool policy, captures metadata on stores, make jobserver implementation, dumping SDags with sorted nodes, tail merging strings in the linker, and more llvmweekly.org/issue/614

LLVM Weekly - #613, September 29th 2025. clang-doc and libc bfloat16 GSoC project results, LLVM's machine scheduler, the future of DependenceAnalysis, {aarch64,riscv64}-unknown-hurd-gnu, software watchpoints in LLDB, and more llvmweekly.org/issue/613

LLVM Weekly - #612, September 22nd 2025. Lightweight Fault Isolation, student travel grant mentors, immutable releases, AI contribution policy, RISCVVLOptimizer improvements, dropping unnecessary assumes, custom clang-tidy checks with clang-query syntax, and more llvmweekly.org/issue/612

LLVM Weekly - #611, September 15th 2025. Ripple: A Compiler-Interpreted API for Efficient SIMD Programming, guidelines for adding/enabling new passes, on 'de-typification' of LLVM IR, lit using internal shell by default for LLVM tests, MLIR IRDL roadmap, and more llvmweekly.org/issue/611

LLVM Weekly - #610, September 8th 2025. LLVM IR byte type, commits via PRs only, ABI lowering library update, LLVM Code Generation book from Quentin Colombet, debugging LLVM, and more llvmweekly.org/issue/610

LLVM Weekly - #609, September 1st 2025. LLVM 21.1.0 released! profiling and testing math functions on GPUs (GSoC), MLIR pattern search, UBSan "trap reasons", early bird registration deadline for dev meeting on Sep 5th, Andrew Pinski launches GNU Tools Weekly, and more llvmweekly.org/issue/609

LLVM Weekly - #608, August 25th 2025. llvm-lit --update-tests, big pointer auth documentation updates, lifetime safety analysis initial use-after-free diagnostic, MLIR remarks, OpenMP unit testing framework, and more llvmweekly.org/issue/608

LLVM Weekly - #607, August 18th 2025. 21.1.0-rc3 (final RC?), Contend Addressable Storage in LLVM, cfi_salt, MLIR Wasm importer, and more llvmweekly.org/issue/607

LLVM Weekly - #606, August 11th 2025. Constant-time selection in Clang for crypto algorithms, tail folding by default for RVV, clangd doxygen parser, WasmSSA MLIR dialect, and more llvmweekly.org/issue/606

LLVM Weekly - #605, August 4th 2025. US LLVM Dev Meeting agenda posted, upstreaming CHERI, restrict in Clang, GlobalISel vs SelectionDAG in 2025, 'hardening' mode for Clang, log level support, debugging Wasm with LLDB, and more llvmweekly.org/issue/605

LLVM Weekly - #604, July 28th 2025. LLVM ❤️ ML workshop, implementing C++17 special math functions with Boost.Math, flang-tidy, LDBG debug logging macro, -f[no]-experimental-lifetime-safety, and more llvmweekly.org/issue/604

Pour one out for NativeClient, finally removed from the LLVM tree last week github.com/llvm/llvm-pr...

LLVM Weekly - #603, July 21st 2025. 21.x branch created, allocator partitioning hint, -opt-disable to disable pass by name, SFrame unwind info, generating dead_on_return attributes, lifetime safety dataflow analysis progress, and more llvmweekly.org/issue/603

LLVM Weekly - #602, July 14th 2025. LLVM Dev Meeting talk and student travel grant deadline TOMORROW (Tue 15th), lifetime safety breakout group, Clang gains an initial intra-procedural flow-sensitive lifetime analysis, minimal DWARF unwinding information checker, and more llvmweekly.org/issue/602

LLVM Weekly - #601, July 7th 2025. AsiaLLVM Dev Meeting videos posted, LLD support for GCC LTO, disallowing struct/array IR values inside functions, XeVM MLIR dialect, and more llvmweekly.org/issue/601

Recordings from last month's AsiaLLVM Developers' Meeting are now up on YouTube www.youtube.com/playlist?lis...

LLVM Weekly - #600, June 30th 2025. Farewell PSTL, 21.x branch date, Flang progress report, reductions in libLLVM dynamic relocations, Windows Secure Hot-patching, and more. Also, 600 LLVM Weekly Issues, still without missing a week(!) llvmweekly.org/issue/600

LLVM Weekly - #599, June 23rd 2025. Functional safety group proposal, stdio.h baremetal support in libc, IRDL principles, InstCombine contributor guide updates, Model Context Protocol (MCP) server support added to LLDB, and more llvmweekly.org/issue/599

LLVM Weekly - #598, June 16th 2025. widechar support for LLVM libc, PGO for cross-compilation, MCP support for LLDB, clang-doc JSON generator, removing PSTL, and more llvmweekly.org/issue/598

LLVM Weekly - #597, June 9th 2025. LLVM Developers' Meeting call for proposals opens, MLIR dialect for WebAssembly, MLIR project lighthouse, what patterns can/should be upstreamed to MLIR, 64-bit source locations, reducing the size of the MC decoder table, and more llvmweekly.org/issue/597

LLVM Weekly - #596, June 2nd 2025. Dataflow analysis in MLIR, RVV code generation improvements overview, more on changing LLVM's release process, removing support for delayed type correction, GPU-side malloc in libc, PTRADD SDag node, and more llvmweekly.org/issue/596

As always, it was great to catch up with people at the RISC-V Summit Europe. I've converted the talk I gave into blog post form - if you have any interest at all in RISC-V vector code generation, read on!

LLVM Weekly - #595, May 26th 2025. AsiaLLVM registration last call, GCC backend for rustc milestone, release process changes proposal, integrated distributed ThinLTO, and more llvmweekly.org/issue/595

LLVM Weekly - #594, May 19th 2025. All EuroLLVM talks now up on YouTube, 20.1.5, dealing with spam on GitHub, EVLIndVarSimplify, polynomial MLIR dialect removed, and more llvmweekly.org/issue/594

LLVM Weekly - #593, May 12th 2025. EuroLLVM videos available, RISC-V LLVM improvements, weighing the cost of each template instantiation, Polonius-inspired intra-procedural lifetime analysis, trivial relocation, and more llvmweekly.org/issue/593

Looks like EuroLLVM 2025 videos have just started appearing online. www.youtube.com/playlist?lis... Thanks to the organisers for consistently ensuring high quality recordings for LLVM Dev Meetings.

I'm on the latest episode the TMPDIR podcast hosted by Khem Raj and Cliff Brake. We talk about various projects I've been involved in (RISC-V, LLVM, lowRISC, Raspberry Pi), current work at @igalia.com, and tech in general. Thanks for having me on! tmpdir.org/043/

LLVM Weekly - #592, May 5th 2025. LLVM LTS discussion updates, quadratic scaling of bufferization, -ftime-report-json, Flang using precompiled headers during build, -Wunterminated-string-initialization, and more llvmweekly.org/issue/592

LLVM Weekly - #591, April 28th 2025. AsiaLLVM program, GCC 15 released, instrumentation framework proposal, linker benchmarking, Flang supported standards, and more llvmweekly.org/issue/591

LLVM Weekly - #590, April 21st 2025. Recent Clang improvements, LLVM_LINK_DYLIB by default?, static analysis roundtable notes, __ptrauth support, Bolt instrumentation support for RISC-V, how maintainers handle post-commit review, and more llvmweekly.org/issue/590

LLVM Weekly - #589, April 14th 2025. See you at EuroLLVM, Qualcomm open sources ELD linker, UEFI platform in LLVM libc, major debug intrinsics removal milestone, type-aware allocation/deallocation, Haiku sanitizer support, and more llvmweekly.org/issue/589

We're looking forward to EuroLLVM next week in Berlin. Be sure to check out talks from my colleague @lukel97.bsky.social and myself on: * Work to further improve RISC-V vector codegen (extending the VL Optimizer), and * Work done with the support of RISE to improve RISC-V LLVM testing.

This week's issue went out with the wrong email subject (claiming to be for March 31st). Sorry about that!