[llvm-dev] LLVM Weekly - #163, Feb 13th 2017

[Alex Bradbury via llvm-dev]

LLVM Weekly - #163, Feb 13th 2017
=================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/163>.

Welcome to the one hundred and sixty-third 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](http://asbradbury.org). 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 recent FOSDEM LLVM devroom are [now
available](https://fosdem.org/2017/schedule/track/llvm_toolchain/).

The majority of the slides for the LLVM performance workshop at CGO [have been
posted online](http://llvm.org/devmtg/2017-02-04/).


## On the mailing lists

* Dylan Mackay has shared a [status update on the AVR
backend](http://lists.llvm.org/pipermail/llvm-dev/2017-February/109980.html).

* Serge Pavlov
[reports](http://lists.llvm.org/pipermail/cfe-dev/2017-February/052573.html)
that he has shared patches to implement a configuration file functionality for
Clang, and gives some extra explanation of its design choices.

* Eric Fiselier
[proposes](http://lists.llvm.org/pipermail/llvm-dev/2017-February/110013.html)
a libcxx-config.py utility to help generate the flags needed to compile and
link libc++.

* Hans Wennborg is keen for [help filling out the 4.0.0 release
notes](http://lists.llvm.org/pipermail/llvm-dev/2017-February/110001.html).

* Michael LeMay has posted an RFC on [using Intel MPX to harden
SafeStack](http://lists.llvm.org/pipermail/llvm-dev/2017-February/109933.html).

* Konstantin Zhuravlyov is looking for feedback on an RFC to [represent
address space information in
DWARF](http://lists.llvm.org/pipermail/llvm-dev/2017-February/109919.html).
This RFC even comes with a series of five patches.


## LLVM commits

* A new PredicateInfo utility has been introduced. This uses extended SSA to
determine what operations are affected by a given predicate, and how
operations are affected by a chain of predicates.
[r294351](http://reviews.llvm.org/rL294351).

* A new `llvm.ssa_copy` intrinsic has been introduced. This allows information
to be attached to operands by copying them and giving them new names.
[r294341](http://reviews.llvm.org/rL294341).

* A few extra substitutions supported in LLVM inline asm have been documented.
[r294204](http://reviews.llvm.org/rL294204).

* Diagnostics for inline assembly have been improved.
[r294458](http://reviews.llvm.org/rL294458).

* The NVPTX code to expand memory intrinsics has been moved to
LowerMemIntrinsics, as a target-independent transform.
[r294490](http://reviews.llvm.org/rL294490).

* Documentation for the Scudo hardened memory allocator has been updated.
[r294595](http://reviews.llvm.org/rL294595).

* llvm-xray has gained support code for representing graphs.
[r294717](http://reviews.llvm.org/rL294717).

* Hexagon instruction definitions have been replaced with auto-generated ones.
[r294753](http://reviews.llvm.org/rL294753).


## Clang commits

* An initial prototype of clangd has been committed. This provides a server
interface to Clang functionality (currently just formatting).
[r294291](http://reviews.llvm.org/rL294291).

* Clang can now generate debug info for C preprocessor macros using the
`-fdebug-macro` flag. [r294637](http://reviews.llvm.org/rL294637).

* The full set of inline asm constraints are now supported for the AVR target.
[r294176](http://reviews.llvm.org/rL294176).

* Support for deducing class template arguments via deduction-guides was
implemented. [r294613](http://reviews.llvm.org/rL294613).

* The safety-no-assembler check will warn if there is any inline assembler
usage (which is disallowed by a number of safety-critical coding standards).
[r294255](http://reviews.llvm.org/rL294255).


## Other project commits

* The process for building libcxx on Windows has been documented.
[r294705](http://reviews.llvm.org/rL294705).

* LLD gained support for the `--emit-relocs` command-line option.
[r294464](http://reviews.llvm.org/rL294464).

* The dependency handling in LLDB's CMake build system has been cleaned up
substantially. [r294515](http://reviews.llvm.org/rL29515).