What once was considered the future of high-performance computing (HPC) in the Aurora supercomputer, is now being forgotten. Intel has removed support for its Xeon Phi Knights Mill and Knights Landing accelerators from the LLVM/Clang 19 compiler, which essentially means cession of support of any kind of the MIC architecture once meant to power an Exascale-class Aurora supercomputer, reports Phoronix .
"Intel has officially announced these products’ EOL on about Aug. 2017," a statement published by Phoronix says. "Even for now, clang/llvm’s supports on these products are incomplete. For example, knm targets has AVX5124FMAPS instructions, while its intrinsic and assembly support is missing. And it is weird that avx5124fmaps is still listed at llvm/include/llvm/TargetParser/X86TargetParser.def."
This follows recent news that the GCC compiler dropped support for Intel's Xeon Phi accelerators, perhaps because of Intel's own cease of support by hardware in general. The deprecation began earlier this year with LLVM/Clang 18, and the complete removal will occur with the LLVM 19 release in September.
Other contributing factors included the previous removals of support in ICC and ICX compilers, which also emitted errors when encountering these accelerators. Intel emphasized that the removal would reduce maintenance efforts, simplifying the development and support processes for current and future compiler versions.
The process of removing support for Xeon Phi began with LLVM/Clang 18, where it was marked as deprecated, according to Phoronix. This aligns with GCC's approach, which deprecated Xeon Phi in version 14 and removed it in version 15. Intel's decision to eliminate support in LLVM/Clang 19 reflects a broader trend across compilers as the company plans to focus on exact AI and HPC programs.
The Aurora supercomputer powered by Intel's codename Xeon Phi and then codenamed Ponte Vecchio compute GPU faced delays and performance issues primarily due to problems with Intel's Sapphire Rapids CPUs and the aforementioned Ponte Vecchio compute GPUs. These hardware issues, along with cooling system malfunctions and other stability problems, prevented Aurora from achieving its full potential.
