Alex Bradbury via llvm-dev
2021-Nov-01 18:10 UTC
[llvm-dev] LLVM Weekly - #409, November 1st 2021
LLVM Weekly - #409, November 1st 2021 ==================================== If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/409>. Welcome to the four hundred and 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](https://www.linkedin.com/in/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 at asbradbury.org>, or @llvmweekly or @asbradbury on Twitter. ## News and articles from around the web The submission form for Round Tables at the 2021 LLVM Dev Meeting [is now available](https://lists.llvm.org/pipermail/llvm-dev/2021-October/153411.html). Videos from CppCon 2021 [have started to be posted](https://pages.jetbrains.com/cppcon2021). Stefan Gränitz blogged about [porting the Cling C++ REPL to LLVM 13 and ORCv2](https://weliveindetail.github.io/blog/post/2021/10/27/cling-llvm13-orcv2.html). ## On the mailing lists * Anton Korobeynikov provided an [update on bugzilla migration](https://lists.llvm.org/pipermail/llvm-dev/2021-October/153457.html), reporting "I believe we were able to work-around the majority of GitHub deficiencies (at least those that were show-stoppers). We are checking the results. Hopefully I will be able to return to you with the final migration roadmap soon." * Carlos Galvez started an RFC thread on [contributing Autosar C++14 guidelines support to clang-tidy](https://lists.llvm.org/pipermail/cfe-dev/2021-October/069176.html). * James Nagourne [proposed](https://lists.llvm.org/pipermail/llvm-dev/2021-October/153479.html) gneeralising Hexagon's VLIWMachineScheduler so it can be used by other targets. * Nimit Singhania started a thread to [propose adding two static analyses to help detect performance issues in GPU programs](https://lists.llvm.org/pipermail/llvm-dev/2021-October/153412.html). * Luís Ferreira posted to discuss [upstreaming an LLDB language plugin for D](https://lists.llvm.org/pipermail/llvm-dev/2021-October/153399.html). * To enable better LLDB+QEMU integration, Pavel Labath [proposed](https://lists.llvm.org/pipermail/lldb-dev/2021-October/017106.html) a new plugin to integrate with user-mode QEMU. * Anrew Kaylor posted an RFC proposing to [eliminate non-IR floating-point controls in the SelectionDAG](https://lists.llvm.org/pipermail/llvm-dev/2021-October/153460.html). 'As a general principle, I would say, "All semantics must be represented in the IR and the backend must respect the IR semantics." And a corollary: "Anything which can be represented at the instruction level must be represented at the instruction level." This corollary would eliminate potential conflicts between function attributes (like "unsafe-fp-math") and individual IR instructions.' Respondents so far are in favour. * Teresa Johnson [shared an RFC](https://lists.llvm.org/pipermail/llvm-dev/2021-October/153435.html) introducing an IR metadata format for the sanitizer-based heap profiler (MemProf) when it is fed back into a subsequent compile for profile guided heap optimisation. * LLVM GPU News #22 [is out](https://lists.llvm.org/pipermail/llvm-dev/2021-October/153500.html). ## LLVM commits * Debug info location tracking was improved for the case where instructions have stack spills fused into them. [ee3eee7](https://reviews.llvm.org/rGee3eee71e415). * The number of RISC-V vector builtins was reduced from ~25000 to ~1100 by sharing bultins for many different types. [e2b7aab](https://reviews.llvm.org/rGe2b7aabb57d5). * Support was added for the AArch64 'R' architecture profile. [8689f5e](https://reviews.llvm.org/rG8689f5e6e773). * A script for building release documentation was committed. [622346c](https://reviews.llvm.org/rG622346c60467). * DeadStoreElimination learned to eliminate redundant stores of an existing value. [f87e0c6](https://reviews.llvm.org/rGf87e0c68d786). * Guidance for buildbot owners was clarified. [a70a563](https://reviews.llvm.org/rGa70a5636a8a4). ## Clang commits * A std::string checker was started as part of the Clang Static Analyzer. [e1fdec8](https://reviews.llvm.org/rGe1fdec875ff1). * Clang vector builtins were documented, and some implementations committed. [025988d](https://reviews.llvm.org/rG025988ded6b2), [025988d](https://reviews.llvm.org/rG025988ded6b2). * git-clang-format gained a --staged/--cached option. [bee61aa](https://reviews.llvm.org/rGbee61aa7b638). ## Other project commits * The [automemcpy framework for automatic generation of fundamental memory operations](https://research.google/pubs/pub50338/) was added to LLVM's libc project. [00c943a](https://reviews.llvm.org/rG00c943a54885). * The base of flang's FIR to LLVM IR MLIR dialect conversion pass was committed. [044d5b5](https://reviews.llvm.org/rG044d5b5dd184). * LLDB's statistics dump command now reports the time it takes to parse and index the symbol tables for each module. [c571988](https://reviews.llvm.org/rGc571988e9d57). * MLIR interfaces were exposed through the Python bindings. [14c9207](https://reviews.llvm.org/rG14c9207063bb). * Support was added for Bazel builds on Windows with clang-cl. [112dc16](https://reviews.llvm.org/rG112dc16014f1).