[llvm-dev] LLVM Weekly - #402, September 13th 2021

[Alex Bradbury via llvm-dev]

LLVM Weekly - #402, September 13th 2021
=======================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/402>.

Welcome to the four hundred and second 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 call for proposals for the LLVM Distributors Conf 2021 [closes on
September
16th](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152552.html).


## On the mailing lists

* Saleem Abdulrasool kicked off a discussion on [supporting
  LLVM_BUILD_LLVM_DYLIB on
  Windows](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152549.html),
  with the goal of enabling smaller LLVM distributions for Windows due to the
  use of dynamic linking. Peter Collingbourne [suggested exploring alternate
  solutions such as multicall
  binaries](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152555.html)

* 13.0.0-rc3 is [running slightly
  late](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152525.html),
  and should be out today.

* Serge Pavolv created a thread on [whether isnan should be optimized out in
  fast-math
  mode](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152530.html),
  and followed up with a [summary of pros/cons on the
  alternatives](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152632.html).

* Philipp Reames [shared a list of common false positive notifications for
  commits](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152587.html),
  e.g. from flaky or slow builders.

* Zixu Wang explains why [clang-doc doesn't fill the same gap as
  clang-extract-api](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152505.html).

* LLVM GPU News #19 [is
  out](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152623.html).

* Mugilan Ganesan [proposes adding a globalmemonly attribute for functions
  that only access global
  memory](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152622.html).

* ORC JIT Weekly #39 [is
  out](https://lists.llvm.org/pipermail/llvm-dev/2021-September/152631.html),
  including coverage of support for SimpleRemoteEPC.


## LLVM commits

* It's now forbidden to mix typed and opaque pointers (on the grounds that
  mixing them introduces new issues and isn't particularly useful).
  [90ec6df](https://reviews.llvm.org/rG90ec6dff860f).

* The IR similarity tool and analyses gained support for recognising branch
  similarity. [bd4b1b5](https://reviews.llvm.org/rGbd4b1b5f6d52).

* MCAsmBackend::writeNopData now takes an MCSubtargetInfo, allowing the
  encoding for a nop to chnage depending on the subtarget.
  [e63455d](https://reviews.llvm.org/rGe63455d5e0e5).

* The IROutliner can now outline single entry/single exit multiblock regions,
  and also gained support for multiple exits.
  [81d3ac0](https://reviews.llvm.org/rG81d3ac0cf2cb),
  [c172f1a](https://reviews.llvm.org/rGc172f1ad39cb).

* Naming of APInt APIs was revised (though old entrypoints have not been
  removed). A similar change has been made to ConstantSDNode.
  [735f467](https://reviews.llvm.org/rG735f46715d90),
  [9af8f1b](https://reviews.llvm.org/rG9af8f1b18e69).

* APInt now supports zero bit integers.
  [704a395](https://reviews.llvm.org/rG704a39569346).

* Initial support was added for .insn in RISC-V.
  [2838797](https://reviews.llvm.org/rG283879793dc7).


## Clang commits

* A new cppcoreguidelines-virtual-base-class-destructor check was added to
  clang-tidy, finding base classes and structs whose destructor is neither
  public and virtual nor protected and non-virtual.
  [c58c7a6](https://reviews.llvm.org/rGc58c7a6ea053).

* clang-nvlink-wrapper was documented.
  [e158363](https://reviews.llvm.org/rGe15836361cdf).


## Other project commits

* gn build files were added for LLDB.
  [cfe0284](https://reviews.llvm.org/rGcfe02847496b).

* Type reconciliation was factored out of MLIR's standard-to-LLVM conversion.
  [8b58ab8](https://reviews.llvm.org/rG8b58ab8ccd81).