As far as I'm aware, ilp32 support for aarch64 has been proposed and implemented, but the patches weren't accepted upstream in the kernel because nobody was abl

As far as I'm aware, ilp32 support for aarch64 has been proposed and implemented, but the patches weren't accepted upstream in the kernel because nobody was able to make a sufficiently convincing case that there was enough benefit to justify adding a whole new ABI to the kernel (there are a few benchmarks where it's noticeable but mostly it just doesn't make enough difference to be worthwhile, AIUI). Possibly the situation has changed since I last heard about it.