Encodings for Flattened Heap Values

A key goal in Project Valhalla is to flatten value objects into their heap containers, while simultaneously upholding all specified behaviors of those containers... This document discusses many implementation options for such heap containers. We pay particular attention to a common but difficult case of flat value storage, where the container is organized as single machine word of up to 64 bits (or maybe 128 bits).

More at https://cr.openjdk.org/~jrose/values/flattened-values.html