[llvm-dev] LLVM Weekly - #91, Sep 28th 2015

[Alex Bradbury via llvm-dev]

LLVM Weekly - #91, Sep 28th 2015
================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/91>.

Welcome to the ninety-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](http://asbradbury.org). 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

Some slides and videos from cppcon have started to appear. See the [slides
from Bjarne Stroustrup's
keynote](https://github.com/isocpp/CppCoreGuidelines/blob/master/talks/Stroustrup%20-%20CppCon%202015%20keynote.pdf)
(which focus on the [Core
Guidelines](https://github.com/isocpp/CppCoreGuidelines) project), as well as
Herb Sutter's slides on [supporting ownership annotations in
C++](https://github.com/isocpp/CppCoreGuidelines/blob/master/talks/Sutter%20-%20CppCon%202015%20day%202%20plenary%20.pdf)
(this will be familiar to anyone who has used Rust). Videos are starting to
appear [on the CppCon Youtube
channel](https://www.youtube.com/playlist?list=PLHTh1InhhwT75gykhs7pqcR_uSiG601oh).

A Microsoft blog says something about [their plans to rejuvenate
MSVC](http://blogs.msdn.com/b/vcblog/archive/2015/09/25/rejuvenating-the-microsoft-c-c-compiler.aspx).
"We will continue to invest in improving our compiler with a goal towards
making it fully standards compliant".


## On the mailing lists

* Jason Kim has posted a [summary of a recent in-person meeting about
ThreadSanitizer, Android, and
AARch64](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090731.html).

* Chris Matthews is planning to work on improving performance change tracking
in LNT, and has posted an [RFC on his
plans](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090616.html).

* The discussion/debate in the 'trouble with triples' thread has [rumbled
on](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090665.html).
There's been a *lot* of in-depth discussion, which I'm afraid I don't have the
time to study and try to summarise fairly. Do dive in if this topic is
important to you. Otherwise, I hope we'll see a summary/RFC once a way forward
is found.

* Jia-Ju Bai is looking for [a way to extract basic loop information from LLVM
IR](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090671.html).
There's a good range of suggested starting points:
[LoopInfoWrapperPass](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090672.html),
[ScalarEvolution](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090673.html),
[InductiveRangeCheckElimination](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090717.html),
and
[Polly](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090720.html).

* Wolfgang Pieb is interested in [extending the liveness of the 'this' pointer
for a better debugging
experience](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090610.html).
His question is whether there's a better way of doing this than creating a new
'fake use' intrinsic. Kevin Smith suggests always storing the 'this' pointer
in memory, but Wolfgang [is concerned about the overhead of this
approach](http://lists.llvm.org/pipermail/llvm-dev/2015-September/090644.html).


## LLVM commits

* The AArch64 machine reassociation code has been refactored to be
target-independent. [r248164](http://reviews.llvm.org/rL248164).

* LLVM's SafeStack now supports Android.
[r248405](http://reviews.llvm.org/rL248405).

* A new target hook has been added for optimizing register copies.
[r248478](http://reviews.llvm.org/rL248478).

* Operand bundles are now supported for CallInst and InvokeInst. Initial
support was also added to LLVM bitcode.
[r248527](http://reviews.llvm.org/rL248527),
[r248551](http://reviews.llvm.org/rL248551).


## Clang commits

* The iOS/OSX localizability checks have been improved.
[r248350](http://reviews.llvm.org/rL248350).

* Some more PS4 toolchain code landed.
[r248546](http://reviews.llvm.org/rL248546).


## Other project commits

* The new ELF linker should now be able to create binaries for FreeBSD.
[r248554](http://reviews.llvm.org/rL248554).

* The new ELF linker gained initial AArch64 support.
[r248641](http://reviews.llvm.org/rL248641).