Alex Bradbury via llvm-dev
2019-Aug-12 20:52 UTC
[llvm-dev] LLVM Weekly - #293, August 12th 2019
LLVM Weekly - #293, August 12th 2019 ================================== If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/293>. Welcome to the two hundred and ninety-third 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 The deadline for submissions to the 2019 LLVM Dev Meeting [is today](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134470.html), Monday 12th August. Applications for [student travel grants](http://llvm.org/devmtg/2019-10/index.html#grant) close on August 16th. Serge Guelton has authored a blog post on [Clang optimisation options](https://developers.redhat.com/blog/2019/08/05/customize-the-compilation-process-with-clang-optimization-options/). ## On the mailing lists * Michael Paszkowski [describes the llvm-canon](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134475.html), developed after seeing Puyan Lotfi's talk on mir-canon. Michal is looking for feedback from the community on the design and implementation of the tool, and has [posted it to Phabricator](https://reviews.llvm.org/D66029). * Richard Trieu has been working on [new clang warnings and improvements to default warnings](http://lists.llvm.org/pipermail/cfe-dev/2019-August/063065.html) and would like further comments and review. * Medhi Amini [summarises](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134452.html) some key elements of the EuroLLVM round table discussion on the use of the Bazel build system for LLVM. * Sjoerd Meijer is [looking for thoughts](http://lists.llvm.org/pipermail/cfe-dev/2019-August/063054.html) on whether setting a transformation option should also imply the transformation (and proposes that it should, and this should be done consistently). * Happy Mahto and a group of other IIT Hyderabad students started an RFC thread on [adding new vectorization pragms to LLVM](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134432.html). Hal Finkel [responded](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134441.html) with some feedback. ## LLVM commits * llvm-readelf learned a new `--stack-sizes` option. [r367942](https://reviews.llvm.org/rL367942). * Initial SVE calling convention support was committed. [r367859](https://reviews.llvm.org/rL367859). * `update_test_checks.py` can now be run in an `--update-only` mode where it will skip any tests that weren't automatically generated. This functionality has also been made available to other `update_*_checks.py` scripts. [r367900](https://reviews.llvm.org/rL367900), [r368174](https://reviews.llvm.org/rL368174). * The new Loop Cache Analysis pass can be used to estimate the number of cache lines required by a loop nest.[r368439](https://reviews.llvm.org/rL368439). * As part of the effort to redesign bugpoint, a new delta IR reduction tool was committed (llvm-reduce). [r368358](https://reviews.llvm.org/rL368358). * x86-experimental-vector-widening-legalization is now enabled by default, which changes the default legalization behaviour for 16/32/64-bit vectors with i8/i16/i32/i64 scalar types from promotion to widening. [r367901](https://reviews.llvm.org/rL367901). * A new KnownBits analysis pass was added for GlobalISel. [r368065](https://reviews.llvm.org/rL368065). * A new llvm.licm.disable metadata was reduced to indicate loop-invariant code motion shouldn't be performed on the indicated loop. [r368296](https://reviews.llvm.org/rL368296). * ABI register names can now be used in assembly constraints for the RISC-V target, meaning frontends no longer need to convert to architectural register names. [r368303](https://reviews.llvm.org/rL368303). ## Clang commits * SVE built-in types have been introduced, which are intended to become sizeless types. [r368413](https://reviews.llvm.org/rL368413). * A new `-stdlib++-isystem` command line option was introduced, allowing explicit control over the C++ standard library search paths. [r367982](https://reviews.llvm.org/rL367982). * ASTImporter now has documentation. [r368009](https://reviews.llvm.org/rL368009). * clang-scan-deps gained a new fast scanning mode, where preprocessing is done on file that are minimised using the dependency directives source minimiser. [r368086](https://reviews.llvm.org/rL368086). ## Other project commits * HWASan learned to instrument globals. [r368102](https://reviews.llvm.org/rL368102). * LLDB was updated to support loading binaries that were linked deterministically on macOS. [r368199](https://reviews.llvm.org/rL368199).