Alex Bradbury via llvm-dev
2020-Oct-19 17:46 UTC
[llvm-dev] LLVM Weekly - #355, October 19th 2020
LLVM Weekly - #355, October 19th 2020 ==================================== If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/355>. Welcome to the three 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](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 A new paper describes an extension to Clang to support syntax plugins, and applies it to embed a DSL directly within a C++ codebase. See [Really Embedding Domain-Specific Languages into C++ for more details](https://arxiv.org/abs/2010.08439). ## On the mailing lists * Roger Ferrer Ibáñez shared an RFC on [code generation for the RISC-V vector extension](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145850.html) and is seeking input on the described strategy. * Serge Guelton provided an [update on the Python 3 migration](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145793.html), where the plan is to require Python 3.6 for LLVM 12.0.0. * Kristof Beyls shared [minutes from a round table on AArch64 pointer authentication ABI at the LLVM Dev Meeting](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145839.html). He also shared [minutes from the LLVM security group round table](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145792.html). * ORC JIT Weekly #24 [is out](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145866.html). Big update: OrcV1 has been removed, removable code has landed, and the C API and lookup system have received significant updates. * Arten Dergachev shared [provides further thoughts on static analyzer and clang-tidy interoperation](http://lists.llvm.org/pipermail/cfe-dev/2020-October/067002.html). * Paul C. Anagnostopoulos shared a [revised proposal for enhancing TableGen's ability to analyze and manipulate DAGs](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145855.html). * Tanya Lattner [offers the use of the Remo collaboration platform for LLVM meetups](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145856.html), noting that the Foundation has a subscription. * Atmn Patel posted an [RFC on introducing the maxobjsize attribute](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145803.html) tracking the size of the object that a pointer points to. * Manman Ren produced a proposal on [providing global analysis and runtime checks for `objc_direct/objc_non_runtime_protocol`](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145753.html), which is currently per-transluation-unit. * Mircea Trofin distributed [notes from the round table on machine learning guided compiler optimisations](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145802.html) that took place at the LLVM Dev Meeting. * Alina Sbirlea shared [meeting notes and a poll for future meetings on MemorySSA](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145766.html). * Simon Moll is [proposing a vector predication round-table this Thursday](http://lists.llvm.org/pipermail/llvm-dev/2020-October/145784.html). ## LLVM commits * Support was added for recording substitutions between pairs of (instruction, operand) numbers using `DBG_INSTR_REF`. [c521e44](https://reviews.llvm.org/rGc521e44defb). * The AArch64 backend implemented stack frame reordering. [2e794a4](https://reviews.llvm.org/rG2e794a46b58). * The LLVM security documentation now has information about expected response time for reports. [05ef552](https://reviews.llvm.org/rG05ef552e566). * The LoopExtract pass was ported to the new pass manager. [518ec05](https://reviews.llvm.org/rG518ec05a104). * The default cutoff threshold for the machine function splitter was updated based on internal benchmarking at Google. [24bf6ff](https://reviews.llvm.org/rG24bf6ff4e08). * The TableGen language gained `!not` and `!xor` operators. [4767bb2](https://reviews.llvm.org/rG4767bb2c0c7). ## Clang commits * X86-64 micro-architecture levels (as defined in the psABI) can now be specified using `-march`. [012dd42](https://reviews.llvm.org/rG012dd42e027). * The `-f[no-]split-code-code` options were introduced to toggle splitting. [273c299](https://reviews.llvm.org/rG273c299d5d6). * Support was added for `-mtune` when targeting RISC-V. [cfa7094](https://reviews.llvm.org/rGcfa7094e49c). ## Other project commits * The runtime component of the recently added memory profiling support was added to compiler-rt. [3d4bba3](https://reviews.llvm.org/rG3d4bba302d2). * Flang's OpenACC lowering now handles the parallel and data constructs. [e944455](https://reviews.llvm.org/rGe944455eaf1), [388d373](https://reviews.llvm.org/rG388d373294e). * Scaffolding for `thread trace dump instructions` was added to LLDB. [26d861c](https://reviews.llvm.org/rG26d861cbbd5). * A linear algebra codegen strategy was added to MLIR. [af5be38](https://reviews.llvm.org/rGaf5be38a010).