LLVM Weekly - #559, September 16th 2024

Welcome to the five hundred and fifty-ninth 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 http://llvmweekly.org and pass it on to anyone else you think may be interested. Please send any tips or feedback to asb@asbradbury.org, @llvmweekly or @asbradbury on Twitter, or @llvmweekly@fosstodon.org or @asb@fosstodon.org.

News and articles from around the web and events

Manuel Brito wrote on the LLVM blog about their GSoC project to improve the NewGVN pass.

The next Portland LLVM social is taking place on September 26th.

The 2024 LLVM Developers’ Meeting Embedded Toolchains Workshop is confirmed for October 22nd and will be an unconference.

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

• Office hours with the following hosts: Phoebe Wang, Johannes Doerfert, Aaron Ballman.
• Online sync-ups on the following topics: Flang, vectorizer, security group, new contributors, LLVM/offload, classic flang, C/C++ language working, floating point, OpenMP for flang, MLIR.
• For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.

On the forums

• Nathan Gauër posted an RFC on testing the SPIR-V backend using spirv-sim.

• Stella Laurenzo shares that MLIR no longer builds the pytorch native interface.

• Alexander Belyaev started an RFC thread on vectors of complx type in MLIR.

• MDevereau proposed using libm’s logf128 for constant folding. Respondents suggested using an implementation from LLVM’s libc.

LLVM commits

• An API was exposed to initialise the SPIRV target and translate the input LLVM IR module to SPIR-V. bca2b6d.

• RISC-V large code model is now supported. fef84c5.

• Improvements to rematerialisation of vmv.v.i for RISC-V reduce the number of spills in SPEC CPU 2017 by 2.5%. 65dc53b.

• The llvm.set.rounding intrinsic was implemented for PowerPC. 06c3311.

• Functions can now be outlined across modules using data generated from a previous codegen. 0f525452.

• A section on AI-generated content was added to the developer policy. 829ea59.

• Assembly (MC layer) support was added for the final WebAssembly exception handling proposal. 6bbf7f0.

• Support was implemented for the new X86 AVX10.2-SATCVT-DS instructions. a409ebc.

• Basic skeleton enablement was added for AMD Zen5. 02e4186.

Clang commits

• The clang-format Visual Studio plugin code was deleted, as Visual Studio has built-in support for running clang-format since VS2017. ddd2af3.

• Documentation was added to RTSan on how to disable it. 60efbe9.

• diagnose_if was extended to accept more detailed warning information. e7f782e.

• The target_clones attribute used for function multiversioning is now supported for RISC-V. 9cd9377.

• A new update-verify-tests.py tool was added, which takes output from a failed clang -verify test and updates it. 9ceb967.

Other project commits

• vdso was implemented in LLVM’s libc. d8e124d.

• LLDB can now calculate the average and the total time for summary providers. 22144e2.

• MLIR dialect conversion now handles dropped block arguments and drop operation results in the same way. 6093c26.

• A --tosa-reduce-transposes pass was added to MLIR. 00f239e4.