llvm dev - Sep 2019 - LLVM Weekly - #299, September 23rd 2019

LLVM Weekly - #299, September 23rd 2019
======================================
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<http://llvmweekly.org/issue/299>.

Welcome to the two hundred and ninety-ninth 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
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## News and articles from around the web

LLVM 9.0.0 [has been
released](http://lists.llvm.org/pipermail/llvm-dev/2019-September/135304.html).
Amongst other highlights, the RISCV backend has been promoted from
"experimental" to "official".

A new post on the LLVM blog [details work to support cross-language LTO
between Rust and
C/C++](http://blog.llvm.org/2019/09/closing-gap-cross-language-lto-between.html).

The Women in Compilers and Tools Workshop held just before the LLVM Dev
Meeting in October [will feature a talk from April Wenssel on Contributing
with
Compassion](http://lists.llvm.org/pipermail/llvm-dev/2019-September/135309.html).


## On the mailing lists

* Serge Guelton shared an RFC on [improving the experience of developing
out-of-tree
passes](http://lists.llvm.org/pipermail/llvm-dev/2019-September/135326.html).
A patch is [up for review](https://reviews.llvm.org/D61446).

* This year, the LLVM Foundation is [selling Supporter
Tickets](http://lists.llvm.org/pipermail/cfe-dev/2019-September/063311.html)
for the LLVM Dev Meeting. These tickets are priced at the full budgeted cost,
giving companies the option to better support the costs of the event.
Additionally, the Foundation is looking for more corporate sponsors.

* Siva Chandra reports that [the LLVM libc now has a repo and mailing
list](http://lists.llvm.org/pipermail/llvm-dev/2019-September/135180.html).

* John McCall
[proposes](http://lists.llvm.org/pipermail/cfe-dev/2019-September/063332.html)
introducing a new level of abstraction in the serializer and deserializer in
order to allow usage from Swift's AST.

* Frank Tetzel is seeking feedback on [the COAT EDSL for just-in-time code
generation](http://lists.llvm.org/pipermail/llvm-dev/2019-September/135259.html).

* Renato Golin gives his [prediction for the timeline of upstream Arm SVE
support](http://lists.llvm.org/pipermail/llvm-dev/2019-September/135231.html).


## LLVM commits

* The first in a series of patches adding support for the data dependence
graph has landed. [r372162](https://reviews.llvm.org/rL372162).

* The LLVM docs gained a new "Getting Involved" article.
[r372487](https://reviews.llvm.org/rL372487).

* The Attributor now supports Heap-to-Stack conversion.
[r371942](https://reviews.llvm.org/rL371942).

* bugpoint gained support for -Oz and fixed -Os support.
[r372079](https://reviews.llvm.org/rL372079).

* The machine scheduler was enabled for the RISC-V backend, albeit with no
target-specific model yet. [r372106](https://reviews.llvm.org/rL372106).

* `update_llc_test_checks.py` gained initial support for MIR inputs.
[r372277](https://reviews.llvm.org/rL372277).

* It's now possible to specify a different encoding for a given instruction
depending on HwMode. [r372320](https://reviews.llvm.org/rL372320).


## Clang commits

* The Clang user manual gained a new section on controlling floating point
behaviour. [r372180](https://reviews.llvm.org/rL372180).

* Clang now accepts `-mcmodel={medany,medlow}` for RISC-V, which are what LLVM
calls 'small' and 'medium' code models.
[r372080](https://reviews.llvm.org/rL372080).

* clangd gained support for semantic selections.
[r371976](https://reviews.llvm.org/rL371976).


## Other project commits

* LLD gained a `--fix-cortex-a8` option to fix processor erratum 657417.
[r371965](https://reviews.llvm.org/rL371965).

* libcxx `std::condition_variable` will be implemented on
`pthread_cond_clockwait` where available.
[r372016](https://reviews.llvm.org/rL372016).

* The LLVM test suite now supports codesigning executables on Darwin.
[r372241](https://reviews.llvm.org/rL372241).