LLVM Weekly - #186, Jul 24th 2017

Welcome to the one hundred and eighty-sixth 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

The LLVM 5.0.0 release branch has been created, and LLVM trunk is now 6.0.0. The bug tracking release blockers is here. The second release candidate is scheduled for August 9th, and the release for August 23rd.

The 9th LLVM Social in Berlin is scheduled for this Thursday at 7pm. Yegor Derevenets will be giving a talk about decompilation. Be sure to register if you would like to attend.

On the mailing lists

• River Riddle has an RFC on adding a new interprocedural outliner. Outlining finds common code sequences and extracts them to separate functions, in order to reduce code size. River has shared the current implementation and a range of code size benchmark results, as well as a useful summary of differences vs the MachineOutliner pass.

• Jakub Kuderski has shared an update on DominatorTree changes and support for incremental updates.

• Ayman Musa is seeking input on recent efforts to generate X86 memory folding tables from TableGen.

• Tim Northover kicked off a discussion on GlobalISel legalization guarantees.

LLVM commits

• An initial scheduling model for AMD's Zen microarchitecture has been added. r308411.

• The AArch64RedundantCopyElimination pass learned to removed more zero copies. r308849.

• Support has been added for the IBM z14 processor. r308194, r308195, r308196.

• Documentation was added on debugging instruction scheduling models. r308476.

• The size of a ThinLTO minimized bitcode file has been further reduced by stripping unneeded information. r308760.

Clang commits

• An initial version of clang-diff has been committed. This is part of a GSoC project, allowing a structural AST diff. r308731.

• Clang's CMake scripts have been improved so the version information can be extracted when building as a git submodule. r308205.

• The huge lib/Basic/Targets.cpp file has been split up into per-target files. r308791.

Other project commits

• GDB index creation in LLD Has been sped up. Thanks to this, linking clang with gdb index now takes 20.8 rather than 34.1 seconds. r308544.

• A recursive taskloop scheduling strategy has been added for OpenMP taskloops. r308338.

• Polly gained a new ForwardOptree pass, which can reduce scalar dependences. r308825.