LLVM Weekly - #368, January 18th 2021

Welcome to the three hundred and sixty-eighth 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 11.0.1 was released.

On the mailing lists

• Mike Edwards sent a reminder about the process of default branch renaming on LLVM github projects.

• In line with the LLVM Proposal Process, Geoffrey Martin-Noble posted a pitch on allowing unsupported build configurations in the LLVM monorepo. This follows on from previous discussions about supporting the Bazel build system.

• Tom Stellard posted an RFC on automated signing of release files.

• Christian Kühnel announced the formation of a new LLVM infrastructure working group, putting out a call for anyone interested to join.

• Vishal Chebrolu looped back to write up his GSoc 2020 project to improve MergeFunctions.

• Arthur Eubanks offers an update on the new pass manager status and timeline from his perspective.

• William Moses proposed the Enzyme automatic differentiation plugin for inclusion in LLVM as an incubator project.

• ORC JIT Weekly #28 is out. A prototype of the new ORC runtime has been posted.

LLVM commits

• The llvm.experimental.noalias.scope.decl intrinsic was introduced, and can be used to identify where a noalias scope is declared. 668827b.

• FastISel was updated to handle materialisations of local constants and addresses in a way that should improve debug info quality. c161775.

• -print-changed gained a quiet mode that will suppress all output when IR doesn't change. 43a830e.

• A number of scalable vector ISel patterns were added for RISC-V. 37b41bd, 7989684, 9ecc991.

• dsymutil gained preliminary support for DWARF 5. f1d5cbb.

• BasicAA was updated to handle recursive queries more efficiently. 0b84afa.

• A scheduling model was added for the Fujitsu A64FX. b543370.

• The targetShrinkDemandedConstant hook was implemented for the RISC-V backend in order to try to ensure immediates are generated that can be used in an ANDI immediate. 86e604c.

Clang commits

• New enforce_tcb and enforce_tcb_leaf attributes were introduced in order to help enforce a Trusted Computing Base by warning when a function with the enforce_tcb attribute calls a function lacking that attribute. 35c9baa.

• mapAnyOf and binaryOperations AST matchers were added. 35c9baa, e810e95.

Other project commits

• LLVM's libc gained implementations of memmove, isascii, and toascii. 2423ec5, 04edcc0.

• libunwind gained support for the VE architecture. 3cbd476.

• Sphinx is now used for generating LLDB's Python API reference rather than epydoc. e7bc6c5.

• MLIR's bufferization docs were updated. e2d7d3c.

• A Complex MLIR dialect was introduced (complex numbers). d0cb0d3.