Alex Bradbury via llvm-dev
2020-Feb-17 20:16 UTC
[llvm-dev] LLVM Weekly - #320, Feb 17th 2020
LLVM Weekly - #320, Feb 17th 2020 ================================ If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/320>. Welcome to the three hundred and twentieth 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 LLVM 10.0.0 RC2 [has been tagged](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139147.html). Don't forget to [register for EuroLLVM'20](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139154.html). The early brid rate will end on Feb 28th. Trip reports are now being posted from the Prague ISO C++ meeting. See the [/r/cpp trip report](https://old.reddit.com/r/cpp/comments/f47x4o/202002_prague_iso_c_committee_trip_report_c20_is/) and [Herb Sutter's](https://herbsutter.com/2020/02/15/trip-report-winter-iso-c-standards-meeting-prague/). Technical work on C++20 was finished at this meeting, and a schedule and set of priorities for C++23 were agreed. ## On the mailing lists * Tanya Lattner notes that the LLVM Code of Conduct has been in draft for several years now, and [outlines the steps and feedback needed to adopt it](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139197.html). She requests that feedback be given within the next two weeks. * Raphael Isemann [proposed that the llgo Go frontend implementation be removed from LLVM](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139058.html). Respondents, including its original author agreed and it has now been removed. * Vinay Madhusudan started a discussion about [the design of the OpenMP dialect in MLIR](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139136.html). The post helpfully starts by summarising the state of various efforts related to this. * Nico Weber suggests [it may be time to move the AVR backend out of experimental](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139158.html). * The 5th installment of the ORC JIT Weekly [is out](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139200.html). Discussion of the new JIT initializer system continues in [D74300](https://reviews.llvm.org/D74300). * Reid Kleckner [proposes storing basic block order in llvm::Instruction for faster local dominance](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139168.html). All respondents so far are in favour. * Simon Moll kicked off an RFC thread on [adding optional named parameter tuples for intrinsics](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139110.html). * Simon Cook proposes [extending TableGen's AssemblerPredictes to support combining feature with ORs](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139138.html). * The thread on representations for loop transformations generated much more discussion. See e.g. [Chris Lattner's latest comments](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139010.html). * Stephan T. Lavavej shares that the list of libcxx test suite tests skipped in MSVC's STL testing environment [is now available](http://lists.llvm.org/pipermail/libcxx-dev/2020-February/000683.html). ## LLVM commits * A document including a proposal and roadmap towards vector predication in LLVM was committed. [c49b9e0](https://reviews.llvm.org/rGc49b9e0d328). * A first version of MemorySSA-based dead store elimination (DSE) was implemented. [d0c4d4f](https://reviews.llvm.org/rGd0c4d4fe092). * The `update_test_check` scripts were updated to allow arguments to be specified within the file, and to allow processing to be turned on/off for parts of the file. [1698cc7](https://reviews.llvm.org/rG1698cc7ebab). * An initial MASM parser was committed. [ee2c0f7](https://reviews.llvm.org/rGee2c0f76d74). * Documentation was added on git bisecting across the MLIR merge. [45c6c82](https://reviews.llvm.org/rG45c6c82e904). * LLVM's libraries were updated to use C++14-style return type deduction. [fb45968](https://reviews.llvm.org/rGfb45968e628). * Support for `-msave-restore` was added to the RISC-V backend. This uses libcalls to implement common save/restore sequences in function prologues and epilogues, reducing code size. [07f7c00](https://reviews.llvm.org/rG07f7c00208b). * A new DWARF transformer class was added to convert DWARF to GSYM. [19602b7](https://reviews.llvm.org/rG19602b71949). * The responsibility for fixing issues in experimental targets was clarified in the developers' policy. [4e1c49c](https://reviews.llvm.org/rG4e1c49cf4d8). * TableGen now allows register class weighting to be overridden. [922197d](https://reviews.llvm.org/rG922197d664d). ## Clang commits * clang-tidy gained a new misc-no-recursion check that flags when recursion is used. [49bffa5](https://reviews.llvm.org/rG49bffa5f8b7). * The outdated document comparing Clang with other compilers was removed. [42ca012](https://reviews.llvm.org/rG42ca012befa). * Clang gained an `-fignore-exceptions` flag. [55e2678](https://reviews.llvm.org/rG55e2678fcd4). * Papers from the Prague 2020 C++ workgroup meeting were added to the Clan status page. [b74a381](https://reviews.llvm.org/rGb74a381296e). ## Other project commits * llgo was deleted. [372bfc6](https://reviews.llvm.org/rG372bfc65deb). * A new utility was added to the libcxx directory to generate and display a header dependency graph. [99382e4](https://reviews.llvm.org/rG99382e450fb). * The SharingPtr class used in LLDB was removed in favour of a regular `std::shared_ptr`. [363f05b](https://reviews.llvm.org/rG363f05b83d9). * LLVM's OpenMP library now builds in C++14 mode by default. [3ff4e2e](https://reviews.llvm.org/rG3ff4e2eee8c).