<!-- READ THIS FIRST: If the feature you are proposing changes the language that GHC accepts or adds any warnings to `-Wall`, it should be written as a [GHC Proposal](https://github.com/ghc-proposals/ghc-proposals/). Other features, appropriate for a GitLab feature request, include GHC API/plugin innovations, new low-impact compiler flags, or other similar additions to GHC. --> ## Motivation It would be nice if we can use SIMD on AArch64 without requiring LLVM. See also #25030. ## Proposal Add support for 128-bit SIMD to AArch64 NCG with ASIMD (NEON). SVE is not in scope of this proposal, because it is not widely available in consumer devices.