This is tracking task to collect information about arm64_32 architecture and what will be needed to support it.

It was introduced with Xcode 10 GM but there is no documentation yet. Example of disassembled code https://gist.github.com/rolfbjarne/24465d3fd9ff53e1a8919b7ea602d976

ILP32 Whitepaper

Milestone I (2018-10)

• Release mode support (llvm_only/bitcode). This is done using the the AOT compiler for armv7k (the old watch) and let LLVM take care to generate correct code for arm64_32.

Milestone II (2019-08)

• Debug mode support for arm64_32 backend. This requires changes in our arm64 backend to be aware of arm64_32. It's needed because our managed debugger doesn't work with LLVM generated code.
• Extend iOS SDK such that we can use it for watchOS too. This allows use to develop arm64_32 related changes outside of Xamarin.iOS.