LLVM News Archives


698 LLVM open-source and Linux related news articles on Phoronix since 2009.

LLVM's BOLT Flipped On By Default For Linux x86/AArch64 Test Releases

BOLT as the Facebook/Meta-developed tech for optimizing binaries in the name of greater performance by optimizing the code layout was merged to mainline LLVM at the start of the year. Now as we approach the end of the year BOLT is getting a bit of a promotion with being flipped on by default for Linux x86_64 and AArch64 test releases.

4 November 2022 - Optimizing Binaries - 8 Comments
LLVM Clang 15 Delivers Some Small x86_64 Performance Improvements But Mostly Flat

Released last month was LLVM/Clang 15 and since then a number of Phoronix readers have been inquiring about Clang 15 compiler benchmarks or there the lack of on Phoronix. I've been testing various Intel and AMD systems with Clang 15, but it hasn't been particularly exciting -- but that's not a bad thing, just that it doesn't make for particularly compelling benchmark articles.

11 October 2022 - LLVM Clang 15 - 4 Comments
Zstd Compression Being Eyed For Use Within LLVM
Zstd Compression Being Eyed For Use Within LLVM

LLVM developers are eyeing Zstandard "Zstd" use within this compiler stack as a secondary compression method to Zlib. Zstd could be used for compressing ELF debug sections, AST data structures, and other purposes within this open-source compiler stack.

25 June 2022 - Zstandard - 11 Comments
LLVM 14.0.2 Released With The Compiler Moving To Bi-Weekly Releases
LLVM 14.0.2 Released With The Compiler Moving To Bi-Weekly Releases

LLVM 14.0.1 released just earlier this month while already LLVM 14.0.2 is out today. LLVM normally sees just a single point release and traditionally happened mid-to-late in the development cycle ahead of LLVM's next major release. But now LLVM is moving to shipping point releases every two weeks.

27 April 2022 - LLVM 14.0.2 - 16 Comments
Initial SPIR-V Backend Code Lands In LLVM 15
Initial SPIR-V Backend Code Lands In LLVM 15

The long in-development work by Intel, The Khronos Group, and other organizations on a proper SPIR-V back-end for LLVM is finally seeing code in mainline. As of last night the initial pieces have landed for the LLVM SPIR-V back-end for this Khronos open standard IR used most notably by Vulkan but for OpenCL and OpenGL as well.

20 April 2022 - SPIR-V Backend, Finally!!! - 3 Comments
Clang'ing The Kernel With Different LLVM Setups Will Be Easier With Linux 5.18

Building the Linux kernel with LLVM/Clang rather than GCC has continued maturing nicely since the support was mainlined two years ago and additional LLVM/Clang functionality continues to be optionally supported by the Linux kernel. With Linux 5.18 there is an improvement around the handling of the LLVM environment variable for dealing with versioned compiler binaries or compiler installations outside of the PATH.

3 April 2022 - More Flexible LLVM - 2 Comments
LLVM Begins Landing The Initial DirectX / HLSL Target Code
LLVM Begins Landing The Initial DirectX / HLSL Target Code

Earlier this month I wrote about Microsoft engineers wanting to add DirectX and HLSL support into the upstream LLVM/Clang compiler. As of this week the very early bits of code are beginning to land in LLVM 15.0 for this Microsoft graphics effort.

28 March 2022 - DirectX Shader Compiler With LLVM - 6 Comments
BOLT Merged Into LLVM To Optimize Binaries For Faster Performance
BOLT Merged Into LLVM To Optimize Binaries For Faster Performance

Merged into LLVM's mono repository minutes ago was BOLT! This is the Facebook-developed tool for optimizing the layout of binaries in the name of delivering greater performance. Facebook (now Meta) already has been using BOLT internally to great success with production workloads, it's continued advancing in the public as open-source for a while, and is now upstream in LLVM for fostering its future development.

11 January 2022 - LLVM BOLT - 25 Comments
LLVM Clang Lands Initial SPIR-V Toolchain Support
LLVM Clang Lands Initial SPIR-V Toolchain Support

An exciting LLVM development has landed in time for Christmas! Complementary to the LLVM SPIR-V back-end work that could soon be mainlined, Clang has now merged the initial SPIR-V toolchain support. This allows going from Clang to the SPIR-V intermediate representation that is conformant to the OpenCL environment specification -- such as for compiling OpenCL kernels into SPIR-V.

23 December 2021 - Generating SPIR-V From OpenCL Kernels - 2 Comments
LLVM's HIPSPV Coming Together For AMD HIP To SPIR-V For OpenCL Execution
LLVM's HIPSPV Coming Together For AMD HIP To SPIR-V For OpenCL Execution

Last week I wrote about the interesting HIPSPV back-end for LLVM to take AMD HIP code -- which generally starts off as NVIDIA CUDA code to begin with before the HIP-ification -- and to be able to output that from the LLVM compiler stack as the SPIR-V intermediate representation used across OpenCL and Vulkan drivers. The goal with this is to be able to take AMD HIP code and ultimately be able to run it on Intel graphics processors but potentially other vendors/drivers too given the vendor-neutral SPIR-V. More of that HIPSPV work is now hitting mainline LLVM.

20 December 2021 - HIPSPV - 13 Comments
Intel, Arm & Khronos Feel Ready to Land SPIR-V Backend Within LLVM
Intel, Arm & Khronos Feel Ready to Land SPIR-V Backend Within LLVM

Engineers from Intel and Arm in cooperation with The Khronos Group feel ready now to begin landing their SPIR-V back-end within the upstream LLVM source tree! This SPIR-V back-end for LLVM would ultimately allow LLVM front-ends for different languages to more easily target this industry-standard shader representation so that it could be ingested by Vulkan / OpenCL drivers.

8 December 2021 - Exciting!!! - 7 Comments
LLVM Now Has "Official" Support For Targeting NEC's Vector Engine (VE)
LLVM Now Has "Official" Support For Targeting NEC's Vector Engine (VE)

The LLVM compiler infrastructure supports not only a growing number of CPU architectures but continues to lead when it comes to its support for different accelerators. Back in 2019 NEC was working to upstream their SX-Aurora VE "Vector Engine" Accelerator and now as of this week that target is considered officially supported upstream.

7 December 2021 - NEC SX-Aurora TSUBASA - 3 Comments
LLVM Clang 14 Lands An "Amazing" Performance Optimization

While the performance of LLVM/Clang has improved a lot over the years and for x86_64 and AArch64 can be neck-and-neck with the GCC compiler, the fierce performance battle is not over. With LLVM/Clang 14.0 due out in the early months of 2022 will be more performance work with one recent commit in particular showing a lot of promise.

6 December 2021 - LLVM Clang 14 - 33 Comments
LLVM Clang 14 Begins Landing Intel AVX-512 FP16 Support

Last month Intel began posting the developer documentation around AVX-512 FP16 support coming with Sapphire Rapids and initially accompanied by GCC compiler patches along with LLVM/Clang. While that GNU Compiler Collection support around AVX-512 FP16 has yet to be merged, the LLVM Clang support for this next iteration of AVX-512 has begun landing.

16 August 2021 - AVX-512 FP16 Support - 8 Comments
Clang PGO Shot Down For Now From The Linux Kernel

While Clang PGO support was sent in for Linux 5.14 as part of Clang compiler handling updates for this next kernel version, the functionality was subsequently dropped out and a new pull request issued after criticism from Linus Torvalds and others.

1 July 2021 - Profile Guided Optimizations - 29 Comments

698 LLVM news articles published on Phoronix.