[llvm-dev] LLVM Weekly - #290, July 22nd 2019

[Alex Bradbury via llvm-dev]

LLVM Weekly - #290, July 22nd 2019
==================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/290>.

Welcome to the two hundred and ninetieth 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 9.0 [has
branched](http://lists.llvm.org/pipermail/llvm-dev/2019-July/134016.html). rc2
is due on 7th August, with the final release scheduled for the 28th of August.
This [blog
post](https://weliveindetail.github.io/blog/post/2019/07/18/llvm9-changes.html)
from Stefan Gränitz has a visualisation of which parts of the codebase have
changed.

A new paper, [AliveInLean: A Verified LLVM Peephole Optimization
Verifier](https://sf.snu.ac.kr/aliveinlean/). It's a reengineered version of
Alive developed in the Lean theorem prover.

Readers might be interested in trip reports from the Cologne ISO C++ Committee
meetings from
[the reddit /r/cpp
team](https://old.reddit.com/r/cpp/comments/cfk9de/201907_cologne_iso_c_committee_trip_report_the/)
and [Herb
Sutter](https://herbsutter.com/2019/07/20/trip-report-summer-iso-c-standards-meeting-cologne/).


## On the mailing lists

* James Molloy is [seeking
feedback](http://lists.llvm.org/pipermail/llvm-dev/2019-July/133923.html) on
some planned refactoring of the MachinePipeliner. Brendan Cahoon gave some
[initial
thoughts](http://lists.llvm.org/pipermail/llvm-dev/2019-July/133954.html).

* Bardia Mahjour shares the [loop optimisation working group
minutes](http://lists.llvm.org/pipermail/llvm-dev/2019-July/133997.html) from
July 17th.

* After further discussion following the mass variable rename in LLD, Chris
Lattner indicates he now thinks [doing such a rename all at once is probably
the right thing to
do](http://lists.llvm.org/pipermail/llvm-dev/2019-July/134039.html).

* Tim Northover provides [really useful guidance on Glue
nodes](http://lists.llvm.org/pipermail/llvm-dev/2019-July/133832.html) in
response to a question on the mailing list.

* Sjoerd Meijer is [seeking
feedback](http://lists.llvm.org/pipermail/llvm-dev/2019-July/133927.html) on
adding a new tail predicate loop pragma, used to indicate a loop tail can be
folded into the main loop.

* Siddharth Bhat [shares an
RFC](http://lists.llvm.org/pipermail/llvm-dev/2019-July/134063.html) on adding
multidimensional array indexing intrinsics. This is motivated by a desire to
improve accuracy of analyses like dependence analysis.


## LLVM commits

* The RISC-V backend is no longer experimental and will be built be default.
[r366331](https://reviews.llvm.org/rL366331).

* Basic codegen support and instrumentation was added for Arm MTE (Memory
Tagging Extension) stack tagging.
[r366360](https://reviews.llvm.org/rL366360),
[r366361](https://reviews.llvm.org/rL366361).

* Support was added for the upcoming Arm Transactional Memory Extension (TME).
[r366322](https://reviews.llvm.org/rL366322).

* The RemarkParser interface was simplified and refactored.
[r366217](https://reviews.llvm.org/rL366217).

* WebAssembly gained support for thread-local storage.
[r366272](https://reviews.llvm.org/rL366272).

* ORCv1 layers and utilities now have deprecation warnings. The intent is to
remove these before LLVM 10.0. Users should transition to ORCv2.
[r366344](https://reviews.llvm.org/rL366344).


## Clang commits

* Lowering was added for the various RISC-V hard float ABIs.
[r366480](https://reviews.llvm.org/rL366480).

* Documentation has been committed for Clang's support of C++ for OpenCL.
[r366351](https://reviews.llvm.org/rL366351).

* The static analyzer docs now cover support for cross-translation unit (CTU)
analysis. [r366439](https://reviews.llvm.org/rL366439).


## Other project commits

* LLD can now emit diagnostics in a Visual Studio friendly way.
[r366333](https://reviews.llvm.org/rL366333).

* SWIG 1.x is no longer supported for LLDB.
[r366213](https://reviews.llvm.org/rL366213).

* lldb-mi was removed, and is now kept in a separate repo on github.
[r366465](https://reviews.llvm.org/rL366465).