LLVM Weekly - #4, Jan 27th 2014

Welcome to the fourth issue of LLVM Weekly, a weekly newsletter (published every Monday) covering developments in LLVM, Clang, and related projects. This marks the end of the first month of operation, here's to many more! 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. I've been keeping the @llvmweekly Twitter account updated throughout the week, so follow that if you want more frequent news updates.

News and articles from around the web

The biggest compiler-related news this week has been the discussions on the GCC mailing list. Things kicked off with Eric S. Raymond's post suggesting that technical progress in GCC is being held back by concerns about reusing parts of GCC in a way that bypasses the copyleft license. Ian Lance Taylor responded to point out that GCC now has a plugin system, albeit with an unstable interface, which mostly put a stop to that line of discussion. However a later post to the mailing list from Richard Stallman has proved very controversial by claiming that "The existence of LLVM is a terrible setback for our community precisely because it is not copylefted and can be used as the basis for nonfree compilers". There's plenty of discussion of these comments around the web at LWN, Hacker News, Reddit, Slashdot etc. Although many of us may have a preference for non-copyleft ('permissive') free software licenses, RMS has consistently and over a long period of time argued that copyleft licenses ultimately do a better job of spreading free software and preserving its freedom. As such, it's not clear to me why this mailing list post has come as a surprise to many. I'm personally surprised he didn't bring up the fact that the BSD-style license used by LLVM contains no explicit patent grant (though LLVM does have a patent policy to help protect its users).

Rapidly moving away from controversial topics, an exciting milestone for the LLVM project was hit this week. The 200000th commit has been applied. Takumi Nakamura was lucky enough to be the one to author that commit.

The Khronos group has released the SPIR 1.2 specification. SPIR is a standardised intermediate representation meant for use with OpenCL, and is based on LLVM 3.2 IR. With the release, the Khronos Group have open sourced a modified Clang 3.2 which can generate SPIR from OpenCL C programs as well as a module verifier.

Joaquín M López Muñoz has published a benchmark comparing hash table performance on Clang. He compares GCC's libstdc++-v3 to the LLVM project's libc++.

The Cambridge (UK) LLVM socials are starting up again, with the next one on the 29th Jan at 7.30pm. Sadly I can't make it, hopefully the next one!

On the mailing lists

LLVM commits

Clang commits

Other project commits

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