[llvm-dev] LLVM Weekly - #391, June 28th 2021

Alex Bradbury via llvm-dev llvm-dev at lists.llvm.org
Mon Jun 28 14:14:31 PDT 2021

LLVM Weekly - #391, June 28th 2021

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Welcome to the three hundred and ninety-first 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.

## News and articles from around the web

No particular news to highlight this week.

## On the mailing lists

* Leonard Chan started an RFC discussion on [building LLVM tools into a single
  and followed up with a [WIP

* Tom Stellard proposed [only changing the libclang.so SONAME when the ABI

* LLVM 12.0.1-rc3 [has been

* Andrew Kaylor started a thread about [floating point variance in the test
  noting that it's still the case that some tests fail if the floating point
  calculations don't exactly match the reference results.

* Nick Desaulniers created an RFC about [inlining and mismatched function
  noting several cases where inlining can produce unexpected or surprising

* Luke Drummond helpfully [summarised the various
  on the thread about appropriate use of the 'NFC' tag.

* Arthur Eubanks initiated a discussion on [ABI attributes on arguments vs

* Alexander Yermolovich is seeking feedback on [refactoring llvm-dwp into a
  library](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151344.html) in
  order to aid the implementation of BOLT.

* Arthur Eubanks is [advertising for help in completing the opaque pointers

* There's been yet more discussion on moving the LLVM mailing lists to
  Discourse. Aaron Ballman [raised a concern about fracturing the

* Anirudh Prasad proposed [a new mechanism for tieing a particular inline asm
  operand to a specific
  that has also been proposed in GCC. Responses so far have been positive.

* David Spickett sent an [update on the patches adding AArch64 memory tagging
  support to
  nothing they are awaiting review.

## LLVM commits

* A new flag was added to force all pointers to be opaque pointers, in order
  to help with testing. [4c8174f](https://reviews.llvm.org/rG4c8174f54b4e).

* The AMDGPU backend gained a new pass to optimise the live ranges of VGPRs.

* The IR verifier will now fail on overrunning and invalid indices for the
  insert/extract vector intrinsics.

* An initial implementation of llvm-sim, an IR similarity visualisation tool,
  was committed. [9e73f7c](https://reviews.llvm.org/rG9e73f7c8d2d7).

* New documentation was added on the use of opt and the new pass manager.

## Clang commits

* clang-format now has basic support for formatting JSON.

* Install targets were created for scan-build-py.

* clang-format gained a new LambdaBodyIndentation option and an IfMacros
  option (a list of macros that should be interpreted as conditionals instead
  of function calls). [64cf5eb](https://reviews.llvm.org/rG64cf5eba06bd),

## Other project commits

* A Bazel build configuration was added to the repo, following approval of
  [the proposal to do

* LLDB can now use LLVM's demangling library to demangle symbols using Rust's
  v0 scheme. [0a2d4f3](https://reviews.llvm.org/rG0a2d4f3f24a3).

* The DFSan shadow and origin memory layouts were modified to match MSan.

* Benchmarks for memcmp and bzero were added to LLVM's libc.

* Libcxx's status ranges implementation status page was updated.

* MLIR's async-parallel-for pass was updated to implement recursive async work
  splitting for scf.parallel operations.

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