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LLVM Weekly - #73, May 25th 2015

Welcome to the seventy-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. Subscribe to future issues at and pass it on to anyone else you think may be interested. Please send any tips or feedback to, or @llvmweekly or @asbradbury on Twitter.

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News and articles from around the web

The LLVM blog has properly announced full support for OpenMP 3.1 in Clang.

The Clang-derived Zapcc has had some attention this week. It claims higher compilation speeds than the baseline Clang or other compilers. Yaron Keren, the principal developer has shared many more details about its implementation on the Clang mailing list.

On the mailing lists

LLVM commits

  • The dereferenceable_or_null attribute will now be exploited by the loop environment code motion pass. r237593.

  • Commits have started on the 'MIR serialization' project, which aims to print machine functions in a readable format. r237954.

  • A GCStrategy for CoreCLR has been committed alongside some documentation for it. r237753, r237869.

  • libFuzzer gained some more documentation. r237836.

  • libFuzzer can now be used with user-supplied mutators. r238059, r238062.

Clang commits

  • -fopenmp will turn on OpenMP support and link with libiomp5 (libgomp can alternatively be specified). r237769.

  • The -mrecip flag has been added to match GCC. r238055.

Other project commits

  • C++1z status for libcxx has been updated. r237606.

  • std::bool_constant and uninitialized_copy() was added to libcxx. r237636, r237699.

  • libcxx gained a TODO list. Plenty of tasks that might be interesting to new contributors. r237813, r237988.

  • LDB has enabled debugging of multithreaded programs on Windows and gained support for attaching to process. r237637, r237817.