[LLVMdev] LLVM Weekly - #43, Oct 27th 2014

[Alex Bradbury]

LLVM Weekly - #43, Oct 27th 2014
================================

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<http://llvmweekly.org/issue/43>.

Welcome to the forty-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](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.

This week it's the LLVM Developers' Meeting in San Jose. Check out the
[schedule](http://llvm.org/devmtg/2014-10/). Unfortunately I won't be there,
so I'm looking forward to the slides and videos going online.


## News and articles from around the web

Philip Reames has written up a detailed [discussion of statepoints vs
gcroot](http://www.philipreames.com/Blog/2014/10/21/statepoints-vs-gcroot-for-representing-call-safepoints/)
for representing call safepoints. The aim is to clearly explain how the
safepoint functionality provided by the [patches currently up for
review](http://reviews.llvm.org/D5683) differ to the current gc.root support.

The Haskell community have put together a [proposal for an improved LLVM
backend to GHC](https://ghc.haskell.org/trac/ghc/wiki/ImprovedLLVMBackend).
They intend to ship GHC with its own local LLVM build.

CoderGears have published a blog post about [using Clang to get better
warnings in Visual C++ projects](http://www.codergears.com/Blog/?p=246).

There is going to be a dedicated LLVM devroom at FOSDEM 2015. Here is the
[call for speakers and
participation](http://article.gmane.org/gmane.comp.compilers.clang.devel/39450).


## On the mailing lists

* Elena Demikhovsky has asked for comments on a [proposal to add masked vector
load and store
intrinsics](http://article.gmane.org/gmane.comp.compilers.llvm.devel/78160).
Essentially all feedback so far is positive on the idea.

* Renato Golin [proposes moving libunwind into
compiler-rt](http://article.gmane.org/gmane.comp.compilers.llvm.devel/78099).
One of the subtleties is hat libunwind isn't fully compatible with GCC's
unwind implementation (due to different data structure layouts), which means
they can't be mixed.

* Kristof Beyls has posted some [notes in preparation for the benchmarking
infrastructure BoF at the LLVM dev
meeting](http://article.gmane.org/gmane.comp.compilers.llvm.devel/78068).


## LLVM commits

* The `nonnull` metadata has been introduced for Load instructions.
[r220240](http://reviews.llvm.org/rL220240).

* minnum and maxnum intrinsics have been added.
[r220341](http://reviews.llvm.org/rL220341),
[r220342](http://reviews.llvm.org/rL220342).

* The Hexagon backend gained a basic disassembler.
[r220393](http://reviews.llvm.org/rL220393).

* PassConfig gained usingDefaultRegAlloc to tell if the default register
allocator is being used. [r220321](http://reviews.llvm.org/rL220321).

* An llvm-go tool has been added. It is intended to be used to build
components such as the Go frontend in-tree.
[r220462](http://reviews.llvm.org/rL220462).


## Clang commits

* C compilation defaults to C11 by default, matching the behaviour of GCC 5.0.
[r220244](http://reviews.llvm.org/rL220244).

* Clang should now be better at finding Visual Studio in non-standard setups.
[r220226](http://reviews.llvm.org/rL220226).

* The Windows toolchain is now known as MSVCToolChain, to allow the addition a
CrossWindowsToolChain which will use clang/libc++/lld.
[r220362](http://reviews.llvm.org/rL220362),
[r220546](http://reviews.llvm.org/rL220546).


## Other project commits

* The libcxxabi gained support for running libc++abi tests with sanitizers.
[r220464](http://reviews.llvm.org/rL220464).