[llvm-dev] LLVM Weekly - #326, Mar 30th 2020

Alex Bradbury via llvm-dev llvm-dev at lists.llvm.org
Mon Mar 30 12:29:12 PDT 2020

LLVM Weekly - #326, Mar 30th 2020

If you prefer, you can read a HTML version of this email at

Welcome to the three hundred and twenty-sixth 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

LLVM 10.0.0 [has been
released](http://lists.llvm.org/pipermail/llvm-dev/2020-March/140233.html). As
always, thank you to everyone who has contributed in any way!

## On the mailing lists

* Kyungwoo Lee wrote an RFC on [homogeneous prolog and epilog for size
optimisation in
This is a code size optimisation that attempts to emit homogeneous stores and
loads with the same offset for prolog and epilog in order to increase the
benefit of machine outlining.

* Philip Reames started a discussion on [the status of Intel JCC
and the desired next steps. As Philip explains, there is currently a
disagreement about how to move forwards.

* Anton Bikineev proposes [allowing custom sections to be under
The motivation is to help security hardening applications that define custom

* Louis Dionne started a discussion on [bumping the CMake version requirement
for libc++ and
This triggered a lot of discussion.

* Bardia Mahjour shared [meeting minutes from the March 25th loop optimisation
working group

* "Whisperity" posted a proposal for [adding 'experimental' checks to

## LLVM commits

* A new algorithm was added to the LLVM Support library to perform the
'optimal' layout of a struct, and it was put to use for coroutine frames.

* MC layer (assembler/disassembler) support was added for Armv8.6-a BFloat16.

* GlobalISel gained new generic opcodes for saturating add/subtract.

* The FREEZE node was added to the SelectionDAG.

* The use of `llvm_unreachable` was further clarified in the LLVM coding
standards. [4778e40](https://reviews.llvm.org/rG4778e409de1).

* Documentation was added on how to deal with issues of slow build time or
memory exhaustion when compiling LLVM.

## Clang commits

* An attribute plugin example was added.

* Support was added for the `cmse_nonsecure_call` and `cmse_nonsecure_entry`
Arm CMSE (Cortex-M Security Extensions) attributes.

* All Arm MVE intrinsics are now implemented.

## Other project commits

* LLVM's libc gained a simple x86-64 Linux loader.

* `SignalContext::GetWriteFlag`, part of the sanitizer infrastructure, was
implemented for RISC-V. [ad1466f](https://reviews.llvm.org/rGad1466f8cbc).

* ThinLTO can now use all hardware threads on the system, rather than being
limited to one thread per core.

* Parallel loop collapsing was implemented in MLIR.

More information about the llvm-dev mailing list