LLVM Weekly - #164, Feb 20th 2017

Welcome to the one hundred and sixty-fourth 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.

News and articles from around the web

Sources and binaries for LLVM 4.0.0-rc2 are now available. Get testing!

The next LLVM social in Berlin will be held on February 23rd.

The next LLVM social in Belgium will be held on the 6th of March.

The NetBSD Foundation has a new blog post summarising recent changes to LLDB for NetBSD support.

Manu Sánchez has blogged about writing AST matchers for libclang.

Version 5 of the DWARF debugging standard has been released.

On the mailing lists

LLVM commits

Support for "debug counters" was added. This is a tool to help narrow down miscompilation to a particular transformation from the command-line. r295595.

The default threshold for full loop unrolling has been increased for the O3 optimisation level, meaning more loops will be unrolled. r295538.

Documentation on LLVM's type-based alias analysis metadata has seen a sizable update. r294999.

Tablegen DAGGenISelDAG gained a new feature to aid debugging instruction selection. r295081.

MachineBlockPlacement learnt to better layout trellis-shaped CFGs. r295223.

Support for the Cavium ThunderX ARM64 processors (including a scheduler) was added. r295475.

Clang commits

The number of UBSan-inserted null checks on C++ object pointers has been significantly reduced. r295391.

Clang's code completion now recognises the previously missing C++11 keywords. r295001.

C++1z class template argument deduction is now considered 'done'. r295011.

The new readability-misleading-indentation checker will warn if indentation around unbraced if/else statements may be misleading (and likely indicate programmer error). r295041.

Other project commits