LLVM Weekly - #299, September 23rd 2019

Welcome to the two hundred and ninety-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. Subscribe to future issues at https://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

LLVM 9.0.0 has been released. Amongst other highlights, the RISCV backend has been promoted from "experimental" to "official".

A new post on the LLVM blog details work to support cross-language LTO between Rust and C/C++.

The Women in Compilers and Tools Workshop held just before the LLVM Dev Meeting in October will feature a talk from April Wenssel on Contributing with Compassion.

On the mailing lists

• Serge Guelton shared an RFC on improving the experience of developing out-of-tree passes. A patch is up for review.

• This year, the LLVM Foundation is selling Supporter Tickets for the LLVM Dev Meeting. These tickets are priced at the full budgeted cost, giving companies the option to better support the costs of the event. Additionally, the Foundation is looking for more corporate sponsors.

• Siva Chandra reports that the LLVM libc now has a repo and mailing list.

• John McCall proposes introducing a new level of abstraction in the serializer and deserializer in order to allow usage from Swift's AST.

• Frank Tetzel is seeking feedback on the COAT EDSL for just-in-time code generation.

• Renato Golin gives his prediction for the timeline of upstream Arm SVE support.

LLVM commits

• The first in a series of patches adding support for the data dependence graph has landed. r372162.

• The LLVM docs gained a new "Getting Involved" article. r372487.

• The Attributor now supports Heap-to-Stack conversion. r371942.

• bugpoint gained support for -Oz and fixed -Os support. r372079.

• The machine scheduler was enabled for the RISC-V backend, albeit with no target-specific model yet. r372106.

• update_llc_test_checks.py gained initial support for MIR inputs. r372277.

• It's now possible to specify a different encoding for a given instruction depending on HwMode. r372320.

Clang commits

• The Clang user manual gained a new section on controlling floating point behaviour. r372180.

• Clang now accepts -mcmodel={medany,medlow} for RISC-V, which are what LLVM calls 'small' and 'medium' code models. r372080.

• clangd gained support for semantic selections. r371976.

Other project commits

• LLD gained a --fix-cortex-a8 option to fix processor erratum 657417. r371965.

• libcxx std::condition_variable will be implemented on pthread_cond_clockwait where available. r372016.

• The LLVM test suite now supports codesigning executables on Darwin. r372241.