Alex Bradbury via llvm-dev
2020-May-25 18:29 UTC
[llvm-dev] LLVM Weekly - #334, May 25th 2020
LLVM Weekly - #334, May 25th 2020 ================================ If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/334>. Welcome to the three hundred and thirty-fourth 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 10.0.1-rc1 [has been tagged](http://lists.llvm.org/pipermail/llvm-dev/2020-May/141683.html). Chris Colman wrote about [improving firmware quality using LLVM and Clang](https://interrupt.memfault.com/blog/arm-cortexm-with-llvm-clang). Djordje Todorovic created a [page tracking debug location coverage in optimised LLVM-produced code](https://djolertrk.github.io/llvm-debug-loc-stats/). Min-Yih Hsu blogged about [using LLVM Lit out-of-tree](https://medium.com/@mshockwave/using-llvm-lit-out-of-tree-5cddada85a78). ## On the mailing lists * Tom Stellard [proposes changes to the LLVM release process](http://lists.llvm.org/pipermail/llvm-dev/2020-May/141730.html), including creating a time-based bug-fix release schedule and eliminating release candidates for bug-fix releases. It also clarifies rules for what kinds of backports are accepted during each release phase. * Nathan Sidwell [shared an implementation of the C++20 module mapper](http://lists.llvm.org/pipermail/cfe-dev/2020-May/065487.html). This was written for GCC, but he shares it under the standard LLVM license. * Vishal Chebrolu will be working on LLVM under GSoC and [shared a proposal for improving MergeFunctions to incorporate MergeSimilarFunction patches and ThinLTO support](http://lists.llvm.org/pipermail/llvm-dev/2020-May/141773.html). * Xing Guo shared an RFC on [adding DWARF support for yaml2obj](http://lists.llvm.org/pipermail/llvm-dev/2020-May/141690.html). * Fangrui Song proposes [an update to the -fuse-ldsemantics](http://lists.llvm.org/pipermail/cfe-dev/2020-May/065518.html), to better specifiy the behaviour for prepending `ld.` or `ld64.`. * There was further discussion around refactoring the class hierarchy of VectorType. Eli Friedman's [response](http://lists.llvm.org/pipermail/llvm-dev/2020-May/141783.html) is perhaps a good starting point. ## LLVM commits * More documentation on using git was added to the getting started guide. [b2d733c](https://reviews.llvm.org/rGb2d733c3507). * The Arm LowOverheadLoops pass can now handle VPT (vector predication) blocks. [835251f](https://reviews.llvm.org/rG835251f7d99). * CodeGen was added for the `preallocated` IR constructs for X86. [8a88755](https://reviews.llvm.org/rG8a88755610d). * A CanonicalizeFreezeInLoops pass was added to address a performance degradation. [d9a4a24](https://reviews.llvm.org/rGd9a4a244138). * It's now possible to generate reproducers for dsymutil. [92fd397](https://reviews.llvm.org/rG92fd3971e0d). * A new isMulhCheaperThanMulshift TargetLowering hook was added. [b631f86](https://reviews.llvm.org/rGb631f86ac5b). ## Clang commits * A new WebkitRefCntblBaseVirtualDtor static analyzer check was implemented, performing analysis of WebKit's reference counted smartpointers. [f7c7e8a](https://reviews.llvm.org/rGf7c7e8a523f). * Support for the nomerge function attribute was added. When added to a statement containing call expressions, those expressions won't be merged during optimisation. [e36076ee](https://reviews.llvm.org/rGe36076ee3a2). * An `addrspace_cast` operator was added for OpenCL in C++ mode. [a6a237f](https://reviews.llvm.org/rGa6a237f2046). * ABIInfo and TargetCodeGenInfo were implemented for the AIX ABI. [7f5d91d](https://reviews.llvm.org/rG7f5d91d3ffe). ## Other project commits * Work to improve LibFuzzer performance by changing how weights are assigned to seeds was committed. [e2e38fc](https://reviews.llvm.org/rGe2e38fca64e). * LLVM's libc implementation gained memset and bzero. [6ca54e0](https://reviews.llvm.org/rG6ca54e01146). * The LLD Mach-O linker gained support for `-order_file` and `.sbuections_via_symbols`. [55e9eb4](https://reviews.llvm.org/rG55e9eb416ee), [4eb6f48](https://reviews.llvm.org/rG4eb6f4854eb).