> however, you are missing significant benefits of x32 vs traditional 32 bit
> added total address space (since you are using a 64 bit kernel)
It's the same with normal 32-bit userspace on a 64-bit kernel.
> added per-process memory (4G instead of 2G)
> twice the number of registers.
> ability to rely on advanced CPU features (compared to i86)
With amd64 you can only rely on SSE and SSE2 being available. I assume it's
the same with x32? You'll still need some sort of cpuid checks for more
recent features and you can do that on normal 32-bit as well.
(Or you can just tell the compiler to assume they are available.)