[llvm-dev] LLVM Weekly - #398, August 16th 2021

[Alex Bradbury via llvm-dev]

LLVM Weekly - #398, August 16th 2021
====================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/398>.

Welcome to the three hundred and ninety-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](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

Intel announced their adoption of LLVM for their C/C++ compilers [is
complete](https://software.intel.com/content/www/us/en/develop/blogs/adoption-of-llvm-complete-icx.html)
and wrote about some of the benefits as well as future plans.

William Woodruff blogged about [parsing LLVM's bitstream
format](https://blog.yossarian.net/2021/08/10/LLVM-internals-part-2-parsing-the-bitstream).

Matthieu Dubet [walked
through](https://blog.matthieud.me/2020/exploring-clang-llvm-optimization-on-programming-horror/)
how Clang/LLVM is able to compile a comically inefficient isEven function down
to 3 LLVM IR instructions.


## On the mailing lists

* "MyDeveloperDay" posted an RFC regarding [clang-format's position on making
  code modifications that might change
  semantics](https://lists.llvm.org/pipermail/llvm-dev/2021-August/152070.html).
  Noting that in general such transformations are frowned upon, but there are
  notable exceptions (like include sorting). This post generated lots of good
  conversation that I can't fully summarise here. Several respondents
  (including [Chris
  Lattner](https://lists.llvm.org/pipermail/llvm-dev/2021-August/152119.html))
  suggested supporting such functionality in an off-by-default manner.

* Henry Linjamäki started an RFC discussing on [emitting HIP device code as
  SPIR-V](https://lists.llvm.org/pipermail/llvm-dev/2021-August/152062.html).

* Jozef Lawrynowicz shared [plans for MSP430
  improvements](https://lists.llvm.org/pipermail/llvm-dev/2021-August/152159.html).


## LLVM commits

* Initial support for X86 AVX512FP16 instructions was added.
  [6f7f5b5](https://reviews.llvm.org/rG6f7f5b54c81b),
  [f1de9d6](https://reviews.llvm.org/rGf1de9d6dae17).

* GlobalISel's RegBankSelect was implemented for M68k.
  [7bdce6b](https://reviews.llvm.org/rG7bdce6bcbda3).

* The process for generating HTML documentation was written up.
  [15acaad](https://reviews.llvm.org/rG15acaad79d6e).


## Clang commits

* A new clang-tidy check was added for enforcing a minimum length for variable
  names. [d2c5cbc](https://reviews.llvm.org/rGd2c5cbc3a856).

* Basic code completion was implemented for attribute names.
  [ece4e920](https://reviews.llvm.org/rGece4e9208521).

* The btf_tag attribute was introduced, allowing an arbitrary string to be
  associated with a structure/member/function/parameter/variable and emitted
  in DWARF output. [1b194ef](https://reviews.llvm.org/rG1b194ef1ab3b).


## Other project commits

* Flang gained support for frontend plugins.
  [f52fc59](https://reviews.llvm.org/rGf52fc591fa34).

* LLVM's libc now has an implementation of strtoll.
  [b062d63](https://reviews.llvm.org/rGb062d639bb3a).