[llvm-dev] LLVM Weekly - #254, November 12th 2018

[Alex Bradbury via llvm-dev]

LLVM Weekly - #254, November 12th 2018
======================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/254>.

Welcome to the two hundred and fifty-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

Volunteers are [being
sought](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127612.html)
for the EuroLLVM'19 Program Committee. If you're interested, get in touch with
Arnaud Allard de Grandmaison by Wednesday.

The Reddit /r/cpp moderators have shared an excellent
[2018 San Diego C++ committee trip
report](https://old.reddit.com/r/cpp/comments/9vwvbz/2018_san_diego_iso_c_committee_trip_report_ranges/).

Stephen Kelly has blogged about [future developments in
clang-query](https://steveire.wordpress.com/2018/11/11/future-developments-in-clang-query/)
and [rewriting code with
clang-tidy](https://blogs.msdn.microsoft.com/vcblog/2018/11/06/exploring-clang-tooling-part-3-rewriting-code-with-clang-tidy/).


## On the mailing lists

* Daniel Sanders kicked off an RFC thread on [Tablegen-erated GlobalISel
combine
rules](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127634.html).
Nicolai Hähnle fed back that [using DAGs rather than MIR code blocks would
have various
advantages](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127642.html)
and Daniel responded with [further reasoning behind the choie to use
MIR](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127676.html).
Quentin Colombet is
[concerned](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127646.html)
that moving away from C++ specified combine rules at this stage may reduce the
opportunity to explore different approaches quickly.

* Kristof Beyls is is [looking for volunteers to help with bug
triaging](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127608.html).
Please take a look at the thread and have a think if this is an area you can
help with.

* James Y Knight has released a [tool to help migrate downstream git repos to
the new monorepo
prototype](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127528.html).
He's also got a new version of the [git repository conversion
prototype](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127544.html).

* Chris Bieneman and Sean Silva
[shared](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127517.html)
[thoughts](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127519.html)
on cl::opt vs libOption.

* Sjoerd Meijer started a thread on [top-down vs bottom-up list shceduling for
in-order
cores](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127543.html).

* Thomas Lively is seeking feedback on whether [NaN payloads should be
preserved through
compilation](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127660.html).

* James Henderson shared an RFC on [making llvm-readobj GNU command-line
compatible](http://lists.llvm.org/pipermail/llvm-dev/2018-November/127534.html).


## LLVM commits

* Documentation was added on bug life cycles. This describes how bugs are
reported, triaged, and closed. [r346299](https://reviews.llvm.org/rL346299).

* Documentation for statepoints was improved.
[r346405](https://reviews.llvm.org/rL346405),
[r346447](https://reviews.llvm.org/rL346447),
[r346448](https://reviews.llvm.org/rL346448).

* The C API bindings for intrinsics have been improved.
[r346195](https://reviews.llvm.org/rL346195).

* ICFLoopSafetyInfo is now used in the LICM (loop invariant code motion)
transform. This uses implicit control flow tracking to keep tracking of
throwing instructions. [r346201](https://reviews.llvm.org/rL346201).

* Initial support was added for PowerPC in llvm-exegesis.
[r346411](https://reviews.llvm.org/rL346411).


## Clang commits

* The clang-cl driver now supports `/clang:` as a mechanism for passing
through arguments to be processed by the clang driver.
[r346393](https://reviews.llvm.org/rL346393).

* Clang gained support for the `cl_intel_device_side_avc_motion_estimation`
extension. [r346326](https://reviews.llvm.org/rL346326).


## Other project commits

* The LLDB Go, Java, and OCaml debugger plugins were removed due to lack of
maintenance. [r346157](https://reviews.llvm.org/rL346157),
[r346158](https://reviews.llvm.org/rL346158),
[r346159](https://reviews.llvm.org/rL346159).

* The LLD COFF linker gained support for Microsoft precompiled headers OBJs.
[r346153](https://reviews.llvm.org/rL346154).