Alex Bradbury via llvm-dev
2018-Jun-04 19:29 UTC
[llvm-dev] LLVM Weekly - #231, June 4th 2018
LLVM Weekly - #231, June 4th 2018 ================================ If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/231>. Welcome to the two hundred and thirty-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 Nathan Froyd [muses](https://blog.mozilla.org/nfroyd/2018/05/29/when-implementation-monoculture-right-thing/) on the possibility of Firefox building using LLVM and Clang across all major platforms, and the advantages/disadvantages/risks of standardising on a single compiler toolchain. ## On the mailing lists * Michael Kruse has written RFCs on [extending #pragma clang loop](http://lists.llvm.org/pipermail/cfe-dev/2018-May/058141.html) and [extending loop metadata in LLVM](http://lists.llvm.org/pipermail/llvm-dev/2018-May/123690.html). As explained in the RFC, the intent is to propose a form of these loop transformation pragmas to the OpenMP standard. * Sohail Somani [proposes](http://lists.llvm.org/pipermail/llvm-dev/2018-May/123632.html) a new API to simplify the interface for creating new forms of debug info metadata. * Anast Gramm reports on an [investigation of the impact of the Scalar Replacement of Aggregates pass on debuginfo](http://lists.llvm.org/pipermail/llvm-dev/2018-May/123665.html). Although the DExTer tool showed SROA had a negative impact on debug experience, Anast's experiment indicated that SROA does a good job of preserving debug information. Greg Bedwell offers [clarification](http://lists.llvm.org/pipermail/llvm-dev/2018-May/123672.html) on some of the subtleties of interpreting DExTer results. ## LLVM commits * A new WebAssembly exception handling prepare pass was added. [r333696](https://reviews.llvm.org/rL333696). * ADDE/ADDC/SUBE/SUBC have been set to expand by default. Out-of-tree backends that use these deprecated opcodes may need to be updated. [r333748](https://reviews.llvm.org/rL333748). * The RISC-V backend gained peepholes to improve codegen for some common global address lowering cases. The intent is to replace these peepholes with a more complete MachineFunctionPass. [r333455](https://reviews.llvm.org/rL333455). * The core logic of LoopInstSimplify has been rewritten to be both simpler and more efficient. [r333461](https://reviews.llvm.org/rL333461). * The MCSchedModel API was extended with new methods for querying latency and reciprocal throughput information for an MCInst. [r333650](https://reviews.llvm.org/rL333650). ## Clang commits * Initial infrastructure for the HIP language has started to land. As explained in the [original RFC](http://lists.llvm.org/pipermail/cfe-dev/2018-March/057426.html), HIP is a language similar to CUDA but with a vendor neutral host API. [r333483](https://reviews.llvm.org/rL333483), [r333484](https://reviews.llvm.org/rL333484). * The `-compiler-option-dump` flag will dump features/extensions lists to a JSON file. [r333653](https://reviews.llvm.org/rL333653). ## Other project commits * The XRay Profile Collector Service has been committed to compiler-rt. [r333624](https://reviews.llvm.org/rL333624). * LLD's WebAssembly linker gained initial support for LTO. [r333570](https://reviews.llvm.org/rL333570).