LLVM Weekly - #359, November 16th 2020

Welcome to the three hundred and fifty-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

Herb Sutter shared a trip report from the Autumn ISO C++ standards meeting.

On the mailing lists

• Mike Edwards shared the plan and timeline for renaming the default LLVM branch to 'main'. The change will take place on December 7th.

• Sander De Smalen shared an update on scalable vectors in LLVM, summarising the current state of support, regulary sync-up meeting timings, and what's next.

• Florian Hahn brought life back to an old discussion on better support for complex numbers, e.g. to support lowering to FCMLA on AArch64.

• ORC JIT Weekly #26 is out, covering The Orc library break-up, remote TargetProcessControl, and the beginnings of a runtime.

• Alexander Yermolovich started a discussion on supporting DWARF64 with debug_info sorting in LLD.

• Sean Silva posted an RFC on adding new SVec and Vec convenience wrappers for SmallVector, aiming to make SmallVector easier to use and more difficult to accidentally misuse.

• Nathan James suggests adding support for a defined initialisation order of plugins in Support/Registry.

• Paul C. Anagnostopoulos shared thoughts on improving performance of TableGen -emit-dag-isel, at a small cost to code size. This triggered further discussion and proposals.

LLVM commits

• llvm-build has been replaced by plain CMake. 9218ff5.

• TableGen gained a !filter bang operator. 91d2e5c.

• !annotation metadata was introduced alongside a pass that emits summary remarks per function with counts for each annotation kind. 8bb6347.

• The AMDGPU backend gained an amdgpu_gfx calling convention. a022b1c.

• A new Orc-RPC based TargetProcessControl implementation was added. 1d0676b.

• The OpenMPIRBuilder gained a CreateCanonicalLoop function. f44ee0f.

• The new -dot-cfg-mssa options creates a dot-cfg file visualising MemorySSA information. 45d459e.

Clang commits

• Initial TableGen definitions of syntax nodes were added. 55120f7, 98aa067.

• The -fproc-stat-report option was introduced, which will generate a report about memory usage and execution time for each called tool. 92d7a84.

• Clang gained support for searching for prebuilt implicit modules. 58c586e.

Other project commits

• Flang's documentation gained a description of problems with DO CONCURRENT. c2bccd6.

• LLD's --time-trace functionality was expanded with new categories. 439341b.

• The lld-macho linker gained basic support for LTO. 21f8311.