LLVM Weekly - #455, September 19th 2022

LLVM Weekly - #455, September 19th 2022

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Welcome to the four hundred and fifty-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 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.

News and articles from around the web

Herb Sutter has presented cppfront, a proposed potential C++ ‘syntax 2’.

Siddhesh Poyarekar writes on the Red Hat blog about new levels of fortification supported in GCC, providing additional protoection against buffer overflows.

On the forums

LLVM commits

  • An IR regularisation pass was added for SPIRV, which performs a number of transformations in order to prepare the LLVM IR for the IR translation. 3544d20.

  • llvm-remarkutil was added, a utility for converting between different types of remarks. 7d80b94.

  • AArch64 implemented ABI lowering for calls to/from streaming SME functions and a design document on this ABI was committed. b00c36c, 4fc2c92, bd4935c.

  • TableGen will now produce a getSubRegisterClass function. 7834194.

  • Fixes were made to the way the MachinePipeliner interprets the scheduling model. 116838b.

Clang commits

  • Clang release notes will now features a “potentially breaking changes” section. e076680.

  • -fsanitizer-coverage=control-flow was added. 3e52c09.

  • The link between -ffast-math and -ffp-contract flags has been broken, matching GCC. 1b69ce1.

Other project commits

  • LLVM’s libc gained implementations of dup, dup2, dup3, access, pread, pwrite, remove, setrlimit, getrlimit, and uname functions. 8989aa0, 419580c, 6e675fb, d23d858, f5cbbb9, 7fb96fb.

  • The performance of exp2f, sinhf, and coshf in LLVM’s libc was improved. e6226e6, 1c89ae7.

  • Relocation scanning in the LLD ELF linker was parallelised, leading to meaningful speedups (e.g. 1.27x as fast for a release Clang with 8 threads on Skylake). e6aebff.

  • MLIR linalg’s vectorisation pattern was retired. 5279e11.