In x86, there is even an ABI for using 64-bit instruction set features (like more registers) while sticking with 32-bit pointers to keep the memory footprint sm

In x86, there is even an ABI for using 64-bit instruction set features (like more registers) while sticking with 32-bit pointers to keep the memory footprint small and fast. (This limits you to 4GB of ram per process, but there are a lot of applications where that's not particularly important.) https://en.wikipedia.org/wiki/X32_ABI https://en.wikipedia.org/wiki/X32_ABI https://lwn.net/Articles/456731/ https://lwn.net/Articles/456731/