Alex Bradbury via llvm-dev
2019-Nov-25 15:23 UTC
[llvm-dev] LLVM Weekly - #308, November 25th 2019
LLVM Weekly - #308, November 25th 2019 ===================================== If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/308>. Welcome to the three hundred and eighth 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 Videos from the LLVM Dev Meeting 2019 [continue to be posted](https://www.youtube.com/channel/UCv2_41bSAa5Y_8BacJUZfjQ/videos). LLVM 9.0.1-rc1 [has been tagged](http://lists.llvm.org/pipermail/llvm-dev/2019-November/137166.html). The call for presentations for EuroLLVM 2020 [is now active](http://lists.llvm.org/pipermail/llvm-dev/2019-November/137142.html). The event will take place April 6-7 in Paris and proposals are due by Jan 11th. ## On the mailing lists * Chandler Carruth kicked off a lengthy RFC thread on [moving towards Discord for real time chat and Discourse for forum/list-style discussions](http://lists.llvm.org/pipermail/llvm-dev/2019-November/136880.html). This proposal follows discussions at the LLVM Dev Meeting and the Women in Compilers and Tools meeting. This proposal has resulted in a large number of responses. A number of people raised concerns about Discord as a proprietary solution. Several respondents suggest it would be productive to separate discussion of the real time chat and the forum solution. * Eric Astor is [proposing to add MASM (Microsoft Macro Assembler) support](http://lists.llvm.org/pipermail/llvm-dev/2019-November/137112.html) to the LLVM MC layer. * Bardia Mahjour shared [minutes from the loop optimisation working group Nov 20th meeting](http://lists.llvm.org/pipermail/llvm-dev/2019-November/137073.html). * Sean Kilmurray posted an RFC on [adding a mock backend target to LLVM](http://lists.llvm.org/pipermail/llvm-dev/2019-November/137002.html) which could be used to test assumptions like the size of bytes or addressable unit sizes. * David Blaikie started a [discussion about DW_OP_implicit_pointer](http://lists.llvm.org/pipermail/llvm-dev/2019-November/136798.html), both from a DWARF perspective and the LLVM implementation. ## LLVM commits * A new API was introduced to determine if an instruction can be safely moved before another instruction. [ae8a8c2](https://reviews.llvm.org/rGae8a8c2db6c). * Scalable vector MVT size queries are now supported. [3f08ad6](https://reviews.llvm.org/rG3f08ad611aa). * llvm-objdump now prints relocation addends in hexadecimal, just like GNU objdump. [6baec97](https://reviews.llvm.org/rG6baec971271). * Scheduling and cost models were added for the Exynos M5. [9bdfee2](https://reviews.llvm.org/rG9bdfee2a3bd). * TableGen will no longer error in the case of duplicate includes. [ee9b49e](https://reviews.llvm.org/rGee9b49eef04). * The CMake build system was updated to explicitly mark libraries defined in lib/ as "component libraries". [ab41180](https://reviews.llvm.org/rGab411801b82). * The new gen-opt-rst TableGen backend will generate "command guides" for common line options, for use in documentation. [64ada7a](https://reviews.llvm.org/rG64ada7accbc). ## Clang commits * Debug info size for Sema was reduced by adding an `anchor()` method, resulting in a 17% saving for Sema object files on Windows and 14.6% on Linux. [586f65d](https://reviews.llvm.org/rG586f65d31f3). * The new clang-tidy performance-no-automatic-move check will flag when constructs prevent automatic move of local variables. [95fe549](https://reviews.llvm.org/rG95fe54931fd). * `-ffixed-rN` can now be used to reserve r6-r11 on ARM. [2d739f9](https://reviews.llvm.org/rG2d739f98d8a). * Support was added for `__attribute__((objc_direct))` and `__attribute__((objc_direct_members))`. [d4e1ba3](https://reviews.llvm.org/rGd4e1ba3fa9d). ## Other project commits * LLVM libc now has a TableGen based header generator. [b47f9eb](https://reviews.llvm.org/rGb47f9eb55d1). * LLDB gained a document describing caveats related to the usage of Python. [0aed648](https://reviews.llvm.org/rG0aed6486497). * LLDB now has some documentation on reproducers. [f19ea6e](https://reviews.llvm.org/rGf19ea6ea5f8). * The Archer tool was added to LLVM's OpenMP implementation. It provides TSan annotations for OpenMP synchronisation. [2b8115b](https://reviews.llvm.org/rG2b8115b10b0).