Alex Bradbury via llvm-dev
2021-Sep-20 20:02 UTC
[llvm-dev] LLVM Weekly - #403, September 20th 2021
LLVM Weekly - #403, September 20th 2021
======================================
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<http://llvmweekly.org/issue/403>.
Welcome to the four hundred and third 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
The recording from the LLVM Distributors' Conf is [available on
YouTube](https://www.youtube.com/watch?v=UMDRAmmDBgM).
The call for proposals for the 2021 LLVM Developers' Meeting has been
[extended to September
27th](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152717.html).
## On the mailing lists
* LLVM 13.0.0-rc3 [has been
tagged](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152657.html).
Tom Stellard also sent a
[reminder](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152698.html)
to put release-13.0.0 in the 'Blocks' field of bugs that you want
fixed in
the 13.0.0 release.
* Petr Hosek proposed [unifying the names of variables used for results of
CMake
checks](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152791.html),
which may allow better deduplication of checks or removal of unnecessary
ones.
* Tom Stellard [proposes deprecating
config.guess](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152717.html).
* Chris Bieneman [followed
up](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152764.html) on
the previous thread on a multi-call ("busybox style") LLVM binary to
share a
prototype of the idea.
* Momchil Velikov shared an RFC proposal for [adding a simple GVN hoisting
transform](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152665.html)
to catch common cases, without enabling the full GVNHoist pass. This
resulted in some
[detailed](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152684.html)
[responses](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152679.html)
from Philip Reames.
* Arthur Eubanks suggested [saving memory by clearing the Clang AST before
running backend optimisations and
codegen](https://lists.llvm.org/pipermail/cfe-dev/2021-September/068930.html).
* Zeson asked about [some of the challenges of i64 being the only legal type
on 64-bit
RISC-V](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152738.html).
[Craig
Topper](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152755.html)
and [Alex
Bradbury](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152803.html)
responded with thoughts.
* Kuba Mracek
[pinged](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152654.html)
for any additional feedback on the introduction of conditional references
between globals in LLVM IR.
* "bd1976" posted an RFC on [emitting additional metadata to
facilitate ELF
hotpatching](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152697.html).
## LLVM commits
* The PowerPC backend can now selected prefixed loads/stores (loads/stories
with a offset fitting into a 34-bit immediate).
[5041a48](https://reviews.llvm.org/rG5041a485b948).
* `LLVM_ENABLE_PER_TARGET_RUNTIME_DIR` was enabled by default on Linux.
[f9dbca6](https://reviews.llvm.org/rGf9dbca68d48e).
* The Arm backend gained a mitigation for CVE-2021-35465 (present in the
Cortex-M33, M35P, and M55).
[1bd5ea9](https://reviews.llvm.org/rG1bd5ea968e92).
* Finalisation and deallocation actions were added to ORC.
[78b083d](https://reviews.llvm.org/rG78b083dbb725).
* A reduce operands pass was added to llvm-reduce.
[f18c073](https://reviews.llvm.org/rGf18c0739b307).
## Clang commits
* A new readability-container-data-pointer check was introduced.
[d0d9e6f](https://reviews.llvm.org/rGd0d9e6f0849b).
* Support was added for delimited escape sequences `\x{XXXX}`, `\u{XXXX}`, and
`\o{OOOO}`. [274adcb](https://reviews.llvm.org/rG274adcb86634).
* Information about C99 was added to Clang's C status page.
[101c3de](https://reviews.llvm.org/rG101c3de39fbc).
## Other project commits
* Following on from a [previous RFC
discussion](https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html),
global state was removed from the LLD/COFF linker.
[6f7483b](https://reviews.llvm.org/rG6f7483b1ece4).
* Documentation was added for flang frontend driver plugins.
[7acf929](https://reviews.llvm.org/rG7acf92943b78).
* A clspv (a compiler for compiling OpenCL C to Vulkan SPIR-V) target was
added to libclc. [21427b8](https://reviews.llvm.org/rG21427b8eb8e7).