[llvm-dev] LLVM Weekly - #319, Feb 10th 2020

[Alex Bradbury via llvm-dev]

LLVM Weekly - #319, Feb 10th 2020
=================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/319>.

Welcome to the three hundred and nineteenth 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

Videos from the FOSDEM LLVM devroom [are now available
online](https://fosdem.org/2020/schedule/track/llvm/).

Bartlomiej Filipek has posted a blog in preparation for the Prague ISO C++
meeting [highlighting a selection of papers and current
status](https://www.bfilipek.com/2020/02/prague.html).


## On the mailing lists

* Erich Keane proposes [supporting an extended integer type in
Clang](http://lists.llvm.org/pipermail/cfe-dev/2020-February/064577.html),
allowing use of LLVM's `iN`. Much of the following discussion was about
whether to be consistent with C's promotion rules, or to have no promotion
rules and require everything be explicit.

* Gábor Márton started an RFC thread on [supporting function summaries in the
Clang Static
Analyzer](http://lists.llvm.org/pipermail/cfe-dev/2020-February/064565.html).

* Petr Penzin has [attempted to summarise the various Fortran LLVM front-end
projects](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139040.html)
and their status.

* Eli Friedman's RFC on [extending shufflevector for vscale
vectors](http://lists.llvm.org/pipermail/llvm-dev/2020-January/138762.html)
generated more discussion this week, e.g. [feedback from Chris
Lattner](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139023.html)
and [from Sander De
Smalen](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139054.html).

* The 4th installment of the ORC JIT Weekly [is
out](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139044.html): A
preview of the new JIT initializer system has been posted in
[D74300](https://reviews.llvm.org/D74300).

* Fangrui Song [provided further feedback on the proposed Propeller post-link
optimisation
framework](http://lists.llvm.org/pipermail/llvm-dev/2020-February/139009.html)
from an LLD perspective.

* Nikita Popov is seeking feedback on [moving IRBuilder to use virtual
dispatch](http://lists.llvm.org/pipermail/llvm-dev/2020-February/138951.html),
moving away from the current design that is templated over a constant folder
and an instruction inserter.

* Fangrui Song [proposes adding a preprocessor to yaml2obj and other YAML
tools](http://lists.llvm.org/pipermail/llvm-dev/2020-February/138905.html).

* Christopher Di Bella is interested in [contributing a ranges implementation
to
libcxx](http://lists.llvm.org/pipermail/libcxx-dev/2020-February/000676.html).


## LLVM commits

* `-stack-clash-protection` was implemented for X86.
[e67cbac](https://reviews.llvm.org/rGe67cbac8121).

* VectorCombine, a new pass for partial vector ops was implemented.
[a17f03b](https://reviews.llvm.org/rGa17f03bd939).

* Initial work started to land to allow preserving information from assumes.
[a7bbe45](https://reviews.llvm.org/rGa7bbe45a3e2).

* The VE backend now supports vararg function callers and callees.
[07c9f75](https://reviews.llvm.org/rG07c9f7574d6).

* ThinLTO was made more efficient when performing export computation,
especially when constant variable importing is enabled.
[bed4d9c](https://reviews.llvm.org/rGbed4d9c8979).

* A `replaceOperand()` helper was introduced to InstCombine.
[878cb38](https://reviews.llvm.org/rG878cb38a5c4).

* The SystemZ backend gained support for `-msoft-float`.
[563e847](https://reviews.llvm.org/rG563e84790f4).

* The AVR backend started to gain some disassembly tests.
[ea8b2cb](https://reviews.llvm.org/rGea8b2cb9bf5).

* AsmPrinter will now print floating point constants in hex instead of decimal
form. [01edae1](https://reviews.llvm.org/rG01edae12717).

* A CallGraph updater helper class was introduced.
[72277ec](https://reviews.llvm.org/rG72277ecd62e).


## Clang commits

* The Clang Static Analyzer started to model STL algorithms, in order to
improve the iterator checkers.
[b198f16](https://reviews.llvm.org/rGb198f16e1e1).

* Support was added for the OpenMP 5.0 `order(concurrent)` clause
[cb8e691](https://reviews.llvm.org/rGcb8e69148db),
[a781521](https://reviews.llvm.org/rGa781521867e).

* As part of the C++20 implementation effort, consteval-specific semantics
were added for functions. [008e7bf](https://reviews.llvm.org/rG008e7bf9234).


## Other project commits

* The MLIR declarative assembly format was documented.
[c1bcdb9](https://reviews.llvm.org/rGc1bcdb935a6).

* MLIR gained initial support for emitting line table information when
exporting to LLVM IR. [c33d697](https://reviews.llvm.org/rGc33d6970e01).

* ELF LLD started to make use of the LLVM time tracing infrastructure.
[e7cb374](https://reviews.llvm.org/rGe7cb3744330).

* The NetBSD Process plugin for LLDB gained support for i386.
[5cc817b](https://reviews.llvm.org/rG5cc817be750).

* LLDB's NetBSD status was documented.
[273f638](https://reviews.llvm.org/rG273f638384d).