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LLVM Weekly - #125, May 23rd 2016

Welcome to the one hundred and twenty-fifth 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

Stephen Kelly has written a blog post about using Clang through the cindex API to automatically generate Python bindings. He also makes use of SIP.

Krister Walfridsson has written a wonderfully clear post on C's type-based aliasing rules.

This week I discovered the Swift Weekly Brief newsletter. Its author, Jesse Squires does a wonderful job of summarising mailing list traffic, recent commits, and discussions on swift-evolution proposals. If you have an interest in Swift development or language design in general I highly recommend it.

Are you interested in writing for the LLVM blog? Or volunteering to help recruit content authors? If so, get in touch with Tanya.

The next Cambridge LLVM Social will be held at 7.30pm on May 25th at the Cambridge Blue.

On the mailing lists

LLVM commits

  • llc will now report all errors in the input file rather than just exiting after the first. r269655.

  • The SPARC backend gained support for soft floating point. r269892.

  • Reloc::Default no longer exists. Instead, Optional<Reloc> is used. r269988.

  • An initial implementation of a "guard widening" pass has been committed. This will combine multiple guards to reduce the number of checks at runtime. r269997.

Clang commits

  • clang-include-fixer gained a basic Vim integration. r269927.

  • The intrinsics headers now have feature guards enabled in Microsoft mode to combat the compile-time regression discussed last week due to their increased size. r269675.

  • avxintrin.h gained many new Doxygen comments. r269718.

Other project commits

  • lld now lets you specify a subset of passes to run in LTO. r269605.

  • LLDB has replaced uses of its own Mutex class with std::mutex. r269877, r270024.