LLVM Weekly - #59, Feb 16th 2015

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. 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@asbradbury.org, or @llvmweekly or @asbradbury on Twitter.

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News and articles from around the web

Reminder, the EuroLLVM 2015 call for papers submission deadline is TODAY. See here for details.

LLVM and Clang 3.6-rc3 has been tagged, any help with testing is greatly appreciated.

On the mailing lists

The discussion about moving towards a singular pointer type has continued. It seems everyone is in favour.
Philip Reames has proposed an attribute that indicates the value is either null or dereferenceable. 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 and proposes modifying Clang to store target defaults on a module.
Alexey Samsonov proposes dropping support for building the sanitizers with autotools. 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.
New intrinsics llvm.eh.begincatch and llvm.eh.endcatch intrinsics have been added to support Windows exception handling. r228733.
A DebugInfoPDB implementation using the MS Debug Interface Access SDK has landed. r228747.
SimplifyCFG will now use TargetTransformInfo for cost analysis. r228826.
A profitability heuristic has been added for the x86 mov-to-push optimisation. r228915.
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.

Clang commits

The /volatile:ms semantics have been implemented, turning volatile loads and stores into atomic acquire and release operations. r229082.

Other project commits

C++14's sized deallocation functions have been implemented in libcxx. r229281.
lld learnt to handle the --wrap option. r228906.
lldb gained the concept of "runtime support values". r228791.
The remote-android platform has been added to lldb. r228943.