LLVM Weekly - #71, May 11th 2015

Welcome to the seventy-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. Subscribe to future issues at https://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

The implementation of OpenMP 3.1 in Clang/LLVM is now complete. Well done to everyone involved.

Most slides from the presentations at EuroLLVM 2015 are now online. Video is coming soon.

Version 3.5.1 of Clang UPC, the Unified Parallel C compiler has been released. The main change seems to be the move to Clang/LLVM 3.5.

The Pony Language, which features an LLVM backend has recently been released. It received quite a lot of discussion on Hacker News.

Many readers might be interested in this update from the last C++ standardization committee meeting.

IBM have posted some bounties for TSAN support and MSAN support for PPC64.

On the mailing lists

• Renato Golin has been asking about interest in improving the LLVM online code coverage report. Joshua Cranmer shared the work he did on code coverage for Thunderbird and Firefox.

• John Criswell has followed up on an older thread about the LLVM DSA work giving some useful insight, and some more.

• Hubert Tong is interested in working on implementing the C++ Concepts Technical Specification in Clang, and would like anyone who's interested in collaborating or has already made a start to get in touch.

• Quentin Colombet has posted a heads-up about his shrink-wrap pass work, including details on how to enable support in your backend (in-tree or out-of-tree).

• Last week's discussion about improving LLD has rumbled on. Chris Lattner suggested working on two linkers, one to serve the needs of those who primarily want a usable BSD-licensed system linker and another a 'next generation' linker trying to meet the original aims of LLD, developed without the same constraints on compatibility. Alex Rosenberg gave a good summary of the original aims of LLD and how recent changes have moved it further from those aims. It looks like a path forwards is being identified.

LLVM commits

• A new 'shrink-wrap' pass has been added. It attempts to insert the prologue and epilogue of a function somewhere other than the entry/exit blocks. See the commit message for a motivating example. r236507.

• Support for the z13 processor and its vector capabilities have been added to the SystemZ backend. r236520, r236521.

• Documentation has been written for the new masked gather and scatter intrinsics. r236721.

• The statepoint intrinsic has been extended to allow statepoints to be marked as transitions from GC-aware code to nonGC-aware code. r236888.

Clang commits

• Clang support for the z13 processor was added. r236531.

• Thread-safe initialization using the MSVC 2015 ABI has been implemented. r236697.

• User-friendly -fsanitize-coverage= flags are now available. r236790.

Other project commits

• libiomp's CMake has been integrated into the LLVM CMake build system, so you can now checkout libiomp and have it built alongside llvm, clang and so on. r236534.