[RFC] [PATCH] 32-bit pointers in x86-64

[Jan Beulich]

>You can't use conventional 32-bit x86 code, so there seems little or no 
>benefit in allowing 32 and 64-bit code to be mixed.

Why not? Switching between 32- and 64-bit modes doesn't involve anything
(apart from knowing the proper selector register values) that cannot be done
purely in user mode. Specifically, I once successfully tried executing 64-bit
code in a 32-bit process.

Jan