The arm64e architecture is used on the A12 chipset, which is added in the latest 2018 iPhone models (XS/XS Max/XR). The code compiles to ARMv8.3, which brings support for new features. Namely:
- Pointer authentication
- Nested virtualization
- Advanced SIMD complex number support
- Improved Javascript data type conversion support
- A change to the memory consistency model
- ID mechanism support for larger system-visible caches
The A12 features an Apple-designed 64-bit ARMv8.3-A six-core CPU
https://en.wikipedia.org/wiki/Apple_A12
Read more about the architecture here as well:
https://community.arm.com/processors/b/blog/posts/armv8-a-architecture-2016-additions