[llvm-dev] LLVM Weekly - #337, June 15th 2020

[Alex Bradbury via llvm-dev]

LLVM Weekly - #337, June 15th 2020
==================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/337>.

Welcome to the three hundred and thirty-seventh 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 2020 Virtual LLVM Developers' Meeting [call for papers is
out](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142224.html), with a
July 15th submission deadline. The Meeting has [been
moved](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142225.html) to
October 6-8 so as not to conflict with the Grace Hopper Conference.


## On the mailing lists

* The first of the new "LLVM Proposals" format [has been
accepted](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142250.html),
"LP001 Introduce a new LLVM process to resolve contentious decisions". As
Review Manager, Chris Lattner summarised the feedback raised in the review.

* JF Bastien provided an [update on the implementation of the LLVM security
group and
process](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142194.html). The
RFC has been out for review for a substantial period of time and the LLVM
board have approved the proposal, so the plan is to start implementing it.

* Hans Wennborg shared the [proposed 11.0 release
schedule](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142172.html).
This would involve creating the release branch on 15th July 2020 and the final
release on 26th August 2020.

* Kai Peter Nacke shared an RFC on [adding support for the z/OS platform to
LLVM and
Clang](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142174.html).

* Min-Yih Hsu [shared work on
Nacro](http://lists.llvm.org/pipermail/cfe-dev/2020-June/065809.html), a small
DSL aiming to provide a better C/C++ macro experience implemented as a Clang
plugin.

* Valeriy Savchenko [started a discussion on regression testing the static
analyzer](http://lists.llvm.org/pipermail/cfe-dev/2020-June/065797.html).

* Andrzej Warzynski provided [a detailed summary of responses to the RFC on
refactoring Clang's frontend/driver/diagnostics
code](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142138.html).

* Serge Guelton write an RFC on [adding a check to ensure passes correctly
indicate if they modified the IR or
not](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142195.html).

* Shoaib Meenai proposed [contributing an LLVM version of Apples libtool
utility to
LLVM](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142157.html).

* Guillaume Chatelet posted an RFC on [adding small bitfield utilities to
LLVM's ADT
library](http://lists.llvm.org/pipermail/llvm-dev/2020-June/142196.html).


## LLVM commits

* An AArch64SLSHardeningPass was introduced to provide hardening for
speculative execution across RET, BR, and BLR instructions.
[0ee176e](https://reviews.llvm.org/rG0ee176edc8b),
[c35ed40](https://reviews.llvm.org/rGc35ed40f4f1).

* The LLVM coding standards documentation was updated to clarify that
single-statement bodies of if/else/loop statements don't have braces.
[c08ea07](https://reviews.llvm.org/rGc08ea077168).

* FileCheck will now default to dumping input upon failure.
[d31c9e5](https://reviews.llvm.org/rGd31c9e5a46e).

* Suffix tree was factored out of the Machine Outliner to allow it to be used
elsewhere. [bb677ca](https://reviews.llvm.org/rGbb677cacc80).

* Structured load intrinsics were added for SVE.
[b82be5d](https://reviews.llvm.org/rGb82be5db71f).

* Additional folding was added for fadd+fmul to fma.
[702cf93](https://reviews.llvm.org/rG702cf933565).

* Numerical expressions in FileCheck now allow calls to predefined functions.
[8fd2270](https://reviews.llvm.org/rG8fd22703702).

* yaml2obj now has a 10mb limit of the output by default.
[3c123ac](https://reviews.llvm.org/rG3c123acf57c).

* A lower complexity X86 Load Value Injection hardening pass was added for O0.
[7e06cf0](https://reviews.llvm.org/rG7e06cf0011a).

* The X86 ASM parser can now harden inline assembly RET instructions against
Load Value Injection. [0cbe713](https://reviews.llvm.org/rG0cbe713c69f).


## Clang commits

* A new `-ftrivial-auto-var-init-stop-after=` flag was introduced to allow
bisections of uninitialised uses of a stack variable exposed by the automatic
variable initialisation. [4db2b70](https://reviews.llvm.org/rG4db2b702486).

* A new `__builtin_matrix_transpose` builtin was added.
[3323a62](https://reviews.llvm.org/rG3323a628ec8).

* Clang static analyser now supports on-demand parsing of needed ASTs during
cross translation unit analysis.
[5cc1851](https://reviews.llvm.org/rG5cc18516c48).

* Clang gained the frontend support necessary for the relative vtables ABI.
[71568a9](https://reviews.llvm.org/rG71568a9e28d).

* `-ffine-grained-bitfield-accesses` will now be more effective on targets
with limited integer widths.
[3dcfd48](https://reviews.llvm.org/rG3dcfd482cb1).


## Other project commits

* LLVM's libc gained implementations of round[f], copysign[f], frexp[f],
logb[f], and modf[f]. [4be1c11](https://reviews.llvm.org/rG4be1c116ad8),
[118c13c](https://reviews.llvm.org/rG118c13c691a).

* MLIR gained the skeleton of a SPIR-V to LLVM dialect conversion.
[fda5192](https://reviews.llvm.org/rGfda5192d4fa).