[llvm-dev] LLVM Weekly - #418, January 3rd 2022

[Alex Bradbury via llvm-dev]

LLVM Weekly - #418, January 3rd 2022
====================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/418>.

Welcome to the four hundred and eighteenth 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](https://www.linkedin.com/in/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 at asbradbury.org>, or
@llvmweekly or @asbradbury on Twitter.

Happy New Year and thank you for reading LLVM Weekly. Amazingly, it's now been
8 full years of LLVM Weekly issues (without missing a single one yet!).


## News and articles from around the web

Recordings of more presentations from the 2021 LLVM Developers' Meeting are
[now available
online](https://www.youtube.com/playlist?list=PL_R5A0lGi1AATJX6-tY7IkYjpRjv30ziN).

Phoronix has written up [2021 LLVM development
statistics](https://www.phoronix.com/scan.php?page=news_item&px=LLVM-Record-Growth-2021),
noting LLVM had a record number of authors in the last year.


## On the mailing lists

* Amir Aupov [provided an update on efforts to prepare BOLT for the LLVM
  monorepo](https://lists.llvm.org/pipermail/llvm-dev/2021-December/154504.html).

* Eugene Zelenko [asked about needed permissions to work with GitHub issue
  labels](https://lists.llvm.org/pipermail/llvm-dev/2021-December/154491.html).
  Anton Korobeynikov will [raise this with the Infrastructure Working
  Group](https://lists.llvm.org/pipermail/llvm-dev/2021-December/154499.html).


## LLVM commits

* Additional InstCombine folds were added for unsigned overflow checks.
  [6c716c8](https://reviews.llvm.org/rG6c716c858950).

* A new pass as added to the Mips backend to avoid a hardware bug with
  back-to-back multiplies on the VR4300.
  [2edcde0](https://reviews.llvm.org/rG2edcde00cb39).

* The process for adding new targets was documented.
  [c5e8eb9](https://reviews.llvm.org/rGc5e8eb9783a6).

* LLVM's command line parsing support library learned to expand `<CFGDIR>` to
  the current file's directory.
  [9d37d0e](https://reviews.llvm.org/rG9d37d0ea3485).

* The constant pool is now used for large integers on RISC-V.
  [41454ab](https://reviews.llvm.org/rG41454ab25645).


## Clang commits

* Support for noreturn destructor calls was added to Clang's dataflow
  analysis. [b5c5d89](https://reviews.llvm.org/rGb5c5d8912e07).

* New diagnostics were added for use of zero-length arrays in SYCL code.
  [52e8f58](https://reviews.llvm.org/rG52e8f58d49e6).


## Other project commits

* LLDB can now cache DWARF indexing results to disk.
  [a2154b1](https://reviews.llvm.org/rGa2154b195153).

* The peak memory requirement for linking with LTO was reduced by using
  `madvise(MADV_DONTNEED)` on some data structures.
  [a96fe1b](https://reviews.llvm.org/rGa96fe1bf3b32).

* libcxx now supports noop_coroutine for GCC.
  [6441536](https://reviews.llvm.org/rG6441536c27cf).

* Various clang-tidy checks were enabled for the MLIR codebase.
  [ab6502ea](https://reviews.llvm.org/rGab6502ea6737).