LLVM News Archives
Red Hat's Tom Stellard Now Serving As LLVM Release Manager

After six years serving as the LLVM release manager and taking over the role from LLVM founder Chris Lattner followed by Bill Wendling, Google's Hans Wennborg has stepped down from his position and handed it over to Red Hat's Tom Stellard.

25 October 2020 - LLVM Release Manager - 8 Comments
LLVM Clang 12 Merges Support For x86_64 Microarchitecture Levels

In an effort to better cater towards newer and common x86_64 instruction set extensions, open-source toolchain developers are moving ahead with the work on x86_64 micro-architecture feature levels for being able to target a handful of different "levels" beyond the base x86_64 instruction set.

22 October 2020 - x86_64 Levels - 10 Comments
Facebook Is Looking To Upstream Their BOLT Binary Performance Optimizer Into LLVM

Facebook's BOLT is a multi-year project focused on speeding up the performance of binaries. This open-source project initially focused on being able to better optimize Linux x86_64/ARM64 ELF binaries as a post-link optimizer. BOLT has been seeing much success with even Google using it now for better performance and now there is work to upstream it as part of the LLVM project.

21 October 2020 - BOLT Optimizer - 2 Comments
Intel Sapphire Rapids Target Added To LLVM/Clang 12.0

Intel developers engaging with upstream LLVM have been adding AMX support and other new features for next year's Xeon "Sapphire Rapids" while as of a few days ago in LLVM 12 Git is the actual enabling of -march=sapphirerapids support.

1 September 2020 - -march=sapphirerapids - 6 Comments
LLVM Merges Machine Function Splitter For ~32% Reduction In TLB Misses

At the beginning of August we reported on Google engineers proposing the Machine Function Splitter to LLVM as a means of making binaries up to a few percent faster thanks to this code generation optimization pass for splitting code functions into hot and cold portions. That work has now been merged into LLVM 12.0 with very promising results.

31 August 2020 - Machine Function Splitter - 18 Comments
LLVM's libclc Adds Mesa SPIR-V Target

Continuing on with all of the OpenCL Mesa work that's been going on by Red Hat developers in recent time, LLVM's libclc library now has support for targeting Mesa SPIR-V.

18 August 2020 - libclc For Mesa - 16 Comments
LLVM Clang 11 Has A Nice Build Speed Improvement With New Feature For Pre-Compiled Headers

There are many improvements in LLVM/Clang 11.0 due out in the weeks ahead though an interesting change merged prior to last month's code branching that slipped under our radar... If using the clang-cl driver for MSVC or when otherwise making use of pre-compiled headers (PCH) functionality, there is a new option that can offer significant build time speed-ups.

8 August 2020 - -fpch-instantiate-templates - 4 Comments
LLVM 11.0-RC1 Now Available For Testing

While LLVM 11.0 was branched almost two weeks ago with many new/improved features for this open-source compiler stack, it has taken until today to get into shape for issuing the first release candidate.

28 July 2020 - LLVM 11.0-RC1 - 2 Comments
LLVM 10.0.1 Finally Ready As Latest Stable Compiler Version

LLVM 10.0 released back in March and today marks the first point release finally shipping. Normally they try to be a bit more punctual in shipping the seldom point releases to LLVM but today marks LLVM 10.0.1 finally being available, just over one month out from the planned LLVM 11.0 debut.

21 July 2020 - LLVM 10.0.1 - 7 Comments
Cling C++ Interpreter Looking To Upstream More Code Into LLVM

Not to be confused with Clang as the well known C/C++ compiler front-end for the LLVM compiler, Cling is a separate project as an interactive, JIT-based C++ interpreter. Cling has been in development for years and at least partially is looking to upstream where possible back into LLVM.

11 July 2020 - CLING - 6 Comments
Apple's Compiler Team Starts Upstreaming Changes For macOS 11

It wasn't even twenty four hours ago that Apple disclosed their plans for transitioning to in-house chips for future laptops and desktops and with that macOS 11. Already we are seeing the first of the LLVM compiler patches being upstreamed in preparing for the wild new Apple future.

23 June 2020 - macOS 11 + LLVM Clang - 25 Comments
LLVM Developers Plotting Path Forward For Moving To A New Git Branch Name

LLVM is the latest open-source project working to shift their Git development terminology away from the "master" branch naming and to something more inclusive. Nearly everyone who voiced their opinion so far were in favor of this change, but there still are open matters such as what to call their new main development branch, the involved technical costs, and how quickly such a transition should happen.

19 June 2020 - Git Terminology - 63 Comments
LLVM Moves Forward With A Security Group For Dealing With Security-Related Issues

Given the increasing number of security issues requiring compiler-based security mitigations with the likes of the Intel LVI attack to Arm Straight Line Speculation just being the two latest examples, Apple's LLVM team has been spearheading a new security group for the upstream LLVM developer community to better manage security-related matters.

13 June 2020 - LLVM Security Group - 4 Comments
If Mitigations Weren't Already Bad Enough: Slow Build Times Now Lead To An Unoptimized Intel LVI Pass

Disclosed back in March was the LVI attack (Load Value Injection) affecting Intel CPUs. Mitigating LVI requires compiler toolchain changes and LLVM 11 merged its LVI mitigation last month that adds a load fence after each instruction that may be vulnerable to this attack, similar to the GNU Assembler changes. Now though LLVM is adding an unoptimized version of their LVI pass.

11 June 2020 - UNOPTIMIZED - 32 Comments
LLVM Lands Support For The Marvell ThunderX3

Announced back in March were the Marvell ThunderX3 Arm server processors with up to 96 cores per SoC and support for 4-way SMT to yield up to 384 threads per socket. These 7nm Arm server processors also support eight channels of DDR4-3200 memory, 64 lanes of PCIe 4.0, and other competitive features for a 2020 server CPU. While we await to see how the ThunderX3 processors perform, the compiler support and other Linux software features are getting all buttoned up.

14 May 2020 - ThunderX3 + LLVM Clang - 3 Comments

630 LLVM news articles published on Phoronix.