LLVM Weekly - #555, August 19th 2024
Welcome to the five hundred and fifty-fifth 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
According to the LLVM calendar in the coming week there will be the following:
- Office hours with the following hosts: Phoebe Wang, Johannes Doerfert.
- Online sync-ups on the following topics: Flang, pointer authentication, SPIR-V, vectoriser improvements, security group, new contributors, LLVM/Offload, Clang C/C++ language working group, loop optimisation, 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
Aaron Ballman started an RFC discussion on changes to the community code ownership policy, suggesting changes to the notion of “code ownership” with the aim of realigning it better with community needs and expectations.
Saleem Abdulrasool started a discussion about dropping support for running LLVM on Windows Vista, 7, and 8.
Issue #69 of the MLIR Newsletter is out.
Justin Stitt proposes adding an operator to invert matches in LLVM’s GlobalPattern implementation.
Louis Dionne explained why a large number of GitHub issues have been created for libc++ recently.
Vlad Serebrennikov noted that pre-commit CI is very slow for a subset of PRs (typically old ones).
Min-Yih Hsu updated the RFC thread on llvm.experimental.get.vector.length.
Michael Clark shared an idea for adding the ability to return alloca memory from a function.
“ahatanak” proposed adding a
__ptrauthqualifier.
LLVM commits
A git “linkify” script was added. If you do
git config core.pager 'llvm/utils/git/linkify | pager'then the script will make text that appears to be a pull request, issue reference, or commit hash into a clickable link. 564efe2.llvm.minimumnum and llvm.maximumnum intrinsics were added, with semantics matching the equivalent minimumNumber and maximumNumber IEEE 754-2019 operations. fb9e685.
SPIR-V virtual register processing was reworked. f9c9806.
The SLP vectorizer learned to keep original scalars in more cases. b10ecfa.
A DXILMetadataAnalysis pass was added to collect DXIL module metadata information in a structure. 03e6675.
Scheduling models were added for the Syntacore SCR4 and SCR5 RISC-V cores. 5ab99bf.
Additional guidance was added for using Graphite for stacked pull requests. 6dcfc84.
A
SelectionDAG::getSignedConstanthelper was introduced. 7afb51e.The
-lsr-term-foldtransformation was split into its own pass. 27a62ec.
Clang commits
A new
-foffload-via-llvmflag was introduced allowing CUDA kernels to be lowered to the new LLVM/Offload API. 80525df.__builtin_is_implicit_lifetimewas implemented. d213981.