[LLVMdev] LLVM Weekly - #59, Feb 16th 2015

[Alex Bradbury]

LLVM Weekly - #59, Feb 16th 2015
================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/59>.

Welcome to the fifty-ninth 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

Reminder, the EuroLLVM 2015 call for papers submission deadline is *TODAY*.
See [here](http://llvm.org/devmtg/2015-04/#callfor) for details.

LLVM and Clang 3.6-rc3 [has been
tagged](http://article.gmane.org/gmane.comp.compilers.clang.devel/41186), any
help with testing is greatly appreciated.


## On the mailing lists

* The discussion about [moving towards a singular pointer
type](http://article.gmane.org/gmane.comp.compilers.llvm.devel/81923) has
continued. It seems everyone is in favour.

* Philip Reames has proposed [an attribute that indicates the value is either
null or
dereferenceable](http://article.gmane.org/gmane.comp.compilers.llvm.devel/82186).
The intended use case is for Java, though it may be useful for various other
higher level languages.

* Duncan P.N. Exon Smith is [concerned that llc is becoming less useful as a
debugging
tool](http://article.gmane.org/gmane.comp.compilers.llvm.devel/82185) and
proposes modifying Clang to store target defaults on a module.

* Alexey Samsonov [proposes dropping support for building the sanitizers with
autotools](http://article.gmane.org/gmane.comp.compilers.llvm.devel/82213).
The autotools build system never reached feature parity with CMake for the
sanitizers and is undertested, there seem to be no objections.


## LLVM commits

* The biggest chunk of internal refactoring of debug metadata has landed, with
the addition of specialized debug info metadata nodes.
[r228640](http://reviews.llvm.org/rL228640).

* New intrinsics llvm.eh.begincatch and llvm.eh.endcatch intrinsics have been
added to support Windows exception handling.
[r228733](http://reviews.llvm.org/rL228733).

* A DebugInfoPDB implementation using the MS Debug Interface Access SDK has
landed. [r228747](http://reviews.llvm.org/rL228747).

* SimplifyCFG will now use TargetTransformInfo for cost analysis.
[r228826](http://reviews.llvm.org/rL228826).

* A profitability heuristic has been added for the x86 mov-to-push
optimisation. [r228915](http://reviews.llvm.org/rL228915).

* PassManager.h is now LegacyPassManager.h. As described in the commit
message, if you are an out of tree LLVM user you may need to update your
includes. [r229094](http://reviews.llvm.org/rL229094).


## Clang commits

* The `/volatile:ms` semantics have been implemented, turning volatile loads
and stores into atomic acquire and release operations.
[r229082](http://reviews.llvm.org/rL229082).


## Other project commits

* C++14's sized deallocation functions have been implemented in libcxx.
[r229281](http://reviews.llvm.org/rL229281).

* lld learnt to handle the `--wrap` option.
[r228906](http://reviews.llvm.org/rL228906).

* lldb gained the concept of "runtime support values".
[r228791](http://reviews.llvm.org/rL228791).

* The remote-android platform has been added to lldb.
[r228943](http://reviews.llvm.org/rL228943).