The 64-bit ARM back-end to the LLVM/Clang compiler now supports generating NEON instructions for AArch64.
NEON is ARM's advanced SIMD instruction set extension for benefiting multimedia and signal processing workloads. ARM NEON has been present going back to the 32-bit Cortex-A8/A9 days and has been supported by the 32-bit compiler back-ends for GCC and Clang. While LLVM/Clang has had initial AArch64
support for several months, the 64-bit ARM back-end hasn't been able to generate NEON instructions.
As of today with this Clang commit
and this LLVM commit
, the 64-bit ARM support includes this very performance beneficial advanced SIMD instruction set.
This 64-bit ARM NEON support is another important new feature for the LLVM 3.4
release that's likely to be out before year's end.