Alex Bradbury via llvm-dev
2021-Jun-28 21:14 UTC
[llvm-dev] LLVM Weekly - #391, June 28th 2021
LLVM Weekly - #391, June 28th 2021 ================================= If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/391>. Welcome to the three hundred and ninety-first 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 No particular news to highlight this week. ## On the mailing lists * Leonard Chan started an RFC discussion on [building LLVM tools into a single binary (busybox-style)](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151321.html), and followed up with a [WIP prototype](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151404.html). * Tom Stellard proposed [only changing the libclang.so SONAME when the ABI changes](https://lists.llvm.org/pipermail/cfe-dev/2021-June/068423.html). * LLVM 12.0.1-rc3 [has been tagged](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151530.html). * Andrew Kaylor started a thread about [floating point variance in the test suite](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151441.html), noting that it's still the case that some tests fail if the floating point calculations don't exactly match the reference results. * Nick Desaulniers created an RFC about [inlining and mismatched function attributes](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151509.html), noting several cases where inlining can produce unexpected or surprising results. * Luke Drummond helpfully [summarised the various responses](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151440.html) on the thread about appropriate use of the 'NFC' tag. * Arthur Eubanks initiated a discussion on [ABI attributes on arguments vs parameters](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151411.html). * Alexander Yermolovich is seeking feedback on [refactoring llvm-dwp into a library](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151344.html) in order to aid the implementation of BOLT. * Arthur Eubanks is [advertising for help in completing the opaque pointers implementation plan](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151310.html). * There's been yet more discussion on moving the LLVM mailing lists to Discourse. Aaron Ballman [raised a concern about fracturing the community](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151429.html). * Anirudh Prasad proposed [a new mechanism for tieing a particular inline asm operand to a specific register](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151370.html), that has also been proposed in GCC. Responses so far have been positive. * David Spickett sent an [update on the patches adding AArch64 memory tagging support to LLDB](https://lists.llvm.org/pipermail/lldb-dev/2021-June/016924.html), nothing they are awaiting review. ## LLVM commits * A new flag was added to force all pointers to be opaque pointers, in order to help with testing. [4c8174f](https://reviews.llvm.org/rG4c8174f54b4e). * The AMDGPU backend gained a new pass to optimise the live ranges of VGPRs. [208332d](https://reviews.llvm.org/rG208332de8abf). * The IR verifier will now fail on overrunning and invalid indices for the insert/extract vector intrinsics. [3c4dbf6](https://reviews.llvm.org/rG3c4dbf6ea9a0). * An initial implementation of llvm-sim, an IR similarity visualisation tool, was committed. [9e73f7c](https://reviews.llvm.org/rG9e73f7c8d2d7). * New documentation was added on the use of opt and the new pass manager. [e15673d](https://reviews.llvm.org/rGe15673df2797). ## Clang commits * clang-format now has basic support for formatting JSON. [8b7881a](https://reviews.llvm.org/rG8b7881a084d0). * Install targets were created for scan-build-py. [d9cf829](https://reviews.llvm.org/rGd9cf8291e7ef). * clang-format gained a new LambdaBodyIndentation option and an IfMacros option (a list of macros that should be interpreted as conditionals instead of function calls). [64cf5eb](https://reviews.llvm.org/rG64cf5eba06bd), [be9a87f](https://reviews.llvm.org/rGbe9a87fe9bc3). ## Other project commits * A Bazel build configuration was added to the repo, following approval of [the proposal to do so](https://github.com/llvm/llvm-www/blob/main/proposals/LP0002-BazelBuildConfiguration.md). [4aeb2e6](https://reviews.llvm.org/rG4aeb2e60df98). * LLDB can now use LLVM's demangling library to demangle symbols using Rust's v0 scheme. [0a2d4f3](https://reviews.llvm.org/rG0a2d4f3f24a3). * The DFSan shadow and origin memory layouts were modified to match MSan. [45f6d55](https://reviews.llvm.org/rG45f6d5522f8d). * Benchmarks for memcmp and bzero were added to LLVM's libc. [87065c0](https://reviews.llvm.org/rG87065c0d242d). * Libcxx's status ranges implementation status page was updated. [e7091da](https://reviews.llvm.org/rGe7091da10b30). * MLIR's async-parallel-for pass was updated to implement recursive async work splitting for scf.parallel operations. [86ad0af](https://reviews.llvm.org/rG86ad0af87054).