[llvm-dev] LLVM Weekly - #266, February 4th 2019

Alex Bradbury via llvm-dev
2019-02-04T20:11:28Z

LLVM Weekly - #266, February 4th 2019
====================================
If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/266>.

Welcome to the two hundred and sixty-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 8.0.0 RC1 [is
available](http://lists.llvm.org/pipermail/llvm-dev/2019-January/129741.html).


# On the mailing lists

* Tim Northover has written an RFC on [supporting `arm64_32` for
AArch64](http://lists.llvm.org/pipermail/llvm-dev/2019-January/129788.html).
This includes AArch64 ILP32 support and support for the custom ABI used to
allow armv7k IR to be compiled to be compatible with `arm64_32`.

* Tom Stellard started an RFC thread on [linear history vs merge
commits](http://lists.llvm.org/pipermail/llvm-dev/2019-January/129723.html)
after migrating to git. This generated copious discussion.

* Simon Moll
[shared](http://lists.llvm.org/pipermail/llvm-dev/2019-January/129791.html) an
RFC on adding native vector predication support to LLVM. It is accompanied by
a prototype implementation.

* Stephen Kelly [has revived the discussion on the use of auto in LLVM
projects](http://lists.llvm.org/pipermail/llvm-dev/2019-February/129912.html).

* Vedant Kumar is [curious about the status of the function merging
pass](http://lists.llvm.org/pipermail/llvm-dev/2019-January/129811.html).

* David Greene
[announces](http://lists.llvm.org/pipermail/llvm-dev/2019-January/129707.html)
that a much improved 'zipping' tool has been released, to help people
migrate
their downstream repositories to the new combined git repo.

* Davide Italiano started an RFC thread on [the future of pexpect in
LLDB](http://lists.llvm.org/pipermail/lldb-dev/2019-January/014654.html).


## LLVM commits

* The LLVM WebAssembly backend was updated to use the new exception handling
proposal. [r352598](http://reviews.llvm.org/rL352598).

* RISC-V RV64F and RV64D codegen (single and double-precision floating point)
support was committed. [r352807](http://reviews.llvm.org/rL352807).

* New variadic avx512 compress/expand intrinsics were added.
[r352343](https://reviews.llvm.org/rL352343).

* The SelectionDAG will now work to avoid re-ordering `DBG_VALUEs`.
[r352350](https://reviews.llvm.org/rL352350).

* A new 'apple-latest' CPU alias was added.
[r352412](https://reviews.llvm.org/rL352412).

* The in-tree gn build system gained a get.py script to download an use a
prebuilt gn. [r352420](http://reviews.llvm.org/rL352420).

* The .align directive now correctly inserts NOPs and the `R_RISCV_ALIGN`
relocation when appropriate for RISC-V.
[r352616](http://reviews.llvm.org/rL352616).

* A 'dynamic' parameter was added to the objectsize intrinsic.
[r352664](http://reviews.llvm.org/rL352664).

* A new FunctionCallee wrapper type was added.
[r352791](http://reviews.llvm.org/rL352791),
[r352833](http://reviews.llvm.org/rL352833).


## Clang commits

* A new `-fapply-gobal-visibility-to-externs` option was added.
[r352391](http://reviews.llvm.org/rL352391).

* clangd implemented textDocument/declaration from the Language Server
Protocol 3.14. [r352864](http://reviews.llvm.org/rL352864).

* clangd gained new interfaces for writing "code tweaks".
[r352494](http://reviews.llvm.org/rL352494).


## Other project commits

* The CoMD Classical Molecular Dynamics Mini-app was added to the LLVM test
suite. This is another DOE proxy app.
[r352375](http://reviews.llvm.org/rL352375).

* libFuzzer gained a new experimental performance optimisation,
`lazy_counters` which is off by default.
[r352700](http://reviews.llvm.org/rL352700).

* The LLD COFF linker supports range extension thunks for ARM64.
[r352929](http://reviews.llvm.org/rL352929).