Alex Bradbury via llvm-dev
2019-Oct-14 18:50 UTC
[llvm-dev] LLVM Weekly - #302, October 14th 2019
LLVM Weekly - #302, October 14th 2019 ==================================== If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/302>. Welcome to the three hundred and second 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 Call for Papers for for the LLVM Dev Room at FOSDEM 2020 [is now open](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135735.html). The deadline is the 24th November, and the devroom will take place on Saturday 1st February in Brussels. The next set of proposed papers for the C++ standard [have now been posted](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/#mailing2019-10). ## On the mailing lists * Tom Stellard shares an [update on the GitHub migration schedule and plans](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135803.html). The plan is to make SVN read-only on the evening of October 21st. * Jeremy Morse [proposes that LLVM adopts Sony's Dexter tool and uses it to run debuginfo-tests](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135773.html). * Tanya Lattner [confirms](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135687.html) that the LLVM Foundation Board of Directors has voted to accept MLIR as a project into LLVM. * Sam Elliott [reports](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135768.html) that the GCC Torture Suite has now been imported into the LLVM test suite. * Josef Eisl has [written a patch](https://reviews.llvm.org/D68213) to add support for embedding bitcode in a binary during LTO. This follows [this earlier RFC](http://lists.llvm.org/pipermail/llvm-dev/2019-January/129657.html). He's actively seeking reviewers. * David Greene kicked off an RFC thread on [end-to-end testing](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135739.html). This generated a lot of discussion that sadly I can't fully summarise. * Galina Kistanova has sent out a [note to buildbot owners](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135870.html) to prepare their bot for the git switchover. * David Tellenbach [submitted a patch](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135731.html) to enable scheduling of CFI instructions to try to address the issue where generated assembly differs depending on whether debug info is generated, but [notes](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135813.html) this approach seems to be a dead-end. He will next try to post-pone insertion of CFI instructions to after machine scheduling. * Serge Guelton is [seeking input on stack clash protection for X86 in LLVM](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135786.html). * The LLVM Dev Meeting is taking place next week and [Tanya Lattner is seeking volunteer moderators](http://lists.llvm.org/pipermail/llvm-dev/2019-October/135720.html). * Siva Chandra has posted the first RFC on the libc-dev mailing list, [proposing "ground truth" description files for the public API](http://lists.llvm.org/pipermail/libc-dev/2019-October/000003.html). ## LLVM commits * A new pass adds support for elimination of dead virtual functions during LTO.[r374539](https://reviews.llvm.org/rL374539). * Support for SVE in LLVM IR continues with the addition of scalable vector size queries and IR instruction support. [r374042](https://reviews.llvm.org/rL374042). * The Attributor can now deduce memory behaviour of functions and arguments. [r373965](https://reviews.llvm.org/rL373965). * The LLVM docs have seen more re-organisation, with the "subsystem documentation" content moving to the User Guides and Reference pages. [r373872](https://reviews.llvm.org/rL373872). * Constrained intrinsics were added for lrint and lround. [r373900](https://reviews.llvm.org/rL373900). * `update_test_checks.py` not accepts `--preserve-names` which means IR names aren't replaced. [r373912](https://reviews.llvm.org/rL373912). * X86 gained a new "tailcc" calling convention that guarantees tail call optimisation. [r373976](https://reviews.llvm.org/rL373976). * `update_cc_test_checks.py` can now handle a `clang | opt | FileCheck` pipeline. [r374287](https://reviews.llvm.org/rL374287). * FileCheck now supports `--ignore-case`. [r374538](https://reviews.llvm.org/rL374538). ## Clang commits * The new `-fgnuc-version=` option allows control of `__GNUC__` and other GCC macros. [r374449](https://reviews.llvm.org/rL374449). * clang-format gained initial support for producing warnings for lines that need reformatting. [r374663](https://reviews.llvm.org/rL374663). * The Clang interface stubs tooling now has end-to-end support for generating ELF interface stubs. [r374061](https://reviews.llvm.org/rL374061). * Clang's OpenMP 5.0 implementation was updated with support for the "master taskloop" directive. [r374437](https://reviews.llvm.org/rL374437). ## Other project commits * The GCC C torture suite was imported into the LLVM test-suite. It can be built using CMake and run using Lit. [r374155](https://reviews.llvm.org/rL374155) and [r374156](https://reviews.llvm.org/rL374156). * LLDB learned to read symbols from `.gnu_debugdata` if present. [r373891](https://reviews.llvm.org/rL373891). * LLDB accelerator table lookups were sped up (accelerated!). [r374401](https://reviews.llvm.org/rL374401).