Alex Bradbury via llvm-dev
2018-Jul-30 19:35 UTC
[llvm-dev] LLVM Weekly - #239, July 30th 2018
LLVM Weekly - #239, July 30th 2018 ================================= If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/239>. Welcome to the two hundred and thirty-ninth 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](https://www.linkedin.com/in/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 at asbradbury.org>, or @llvmweekly or @asbradbury on Twitter. ## News and articles from around the web GCC 8.2 has been [released](https://gcc.gnu.org/ml/gcc-announce/2018/msg00002.html). ## On the mailing lists * Kirill Bobyrev [proposes](http://lists.llvm.org/pipermail/llvm-dev/2018-July/124888.html) moving the google-benchmark library into the main LLVM repository. It's currently included in libcxx and the test-suite, and clangd would now like to use it. Responses are positive so far. * Craig Topper starts a discussion on [improving the performance of dot product reduction loops](http://lists.llvm.org/pipermail/llvm-dev/2018-July/124786.html). * Philip Reames [shares](http://lists.llvm.org/pipermail/llvm-dev/2018-July/124829.html) a couple of ideas for extensions of the loop unswitch cost model. * Alexandros Lamprineas is [seeking feedback](http://lists.llvm.org/pipermail/llvm-dev/2018-July/124871.html) on re-enabling GVNHoist by default. * Matthew Arsenault starts a discussion about [the behaviour of the llvm.minnum/llvm.maxnum intrinsics](http://lists.llvm.org/pipermail/llvm-dev/2018-July/124770.html). He points out that the behaviour doesn't match IEEE-754 as the LangRef currently suggests. Stephen Canon [helpfully clarifies](http://lists.llvm.org/pipermail/llvm-dev/2018-July/124870.html) recent changes to the IEEE-754 standard with respect to these operations. ## LLVM commits * The MachineOutliner is now enabled by default under -Oz for AArch64. This offers an additional 4.5% code size improvements. [r338133](https://reviews.llvm.org/rL338133). * A new ArmCodeGenPrepare backend pass was added in order to perform type promotion on icmp operands. [r337687](https://reviews.llvm.org/rL337687). * The BPF backend gained a new `-bpf-expand-memcpy-in-order` option. [r337977](https://reviews.llvm.org/rL337977). * MC support for the Armv8.2-A crypto extensions was added. [r338010](https://reviews.llvm.org/rL338010). * The RISC-V backend gained support for the 'interrupt' function attribute. [r338047](https://reviews.llvm.org/rL338047). ## Clang commits * Clang learned to use non-zero memset when possible for automatic variables. [r337887](https://reviews.llvm.org/rL337887). * Clang's OpenMP documentation was updated to describe recent changes. [r338049](https://reviews.llvm.org/rL338049). ## Other project commits * The compiler-rt profiling runtime is now supported on Fuchsia. [r337881](https://reviews.llvm.org/rL337881). * `<span>` was implemented in libcxx. [r337804](https://reviews.llvm.org/rL337804). * A design document was committed to libcxx for an upcoming `file_time_type` change. The described change, using `__int128_t` was also committed this week. [r337880](https://reviews.llvm.org/rL337880), [r337960](https://reviews.llvm.org/rL337960). * `<filesystem>` was implemented in libcxx. The symbols are placed in libc++fs.a rather than libc++.so. [r338093](https://reviews.llvm.org/rL338093). * The hotspot and srad kernels from the Rodinia benchmark were added to the LLVM test suite. [r338168](https://reviews.llvm.org/rL338168), [r338169](https://reviews.llvm.org/rL338169).