1GB process size limit on sparc64

I noticed that you can not have MAXDSIZ > (1*1024*1024*1024) even on a 
64 bit platform. The 64bit values are #if 0ed out in vmparam.h IS there 
any work being planned to fix this any time soon? Coming from Solaris 
this really bugs me.

I may not want every process on the system sucking up 1GB or more but I 
sure want to be able to work with more memory in a single process if I 
need to. (what if you want to mmap a file larger than 1GB?)

The comment in the 32bit part of the vmparam.h file suggests that going 
over those limits causes hangs in the kernel due to integer overflows is 
this still the case? how much work would need to be done to get this 
working with the sparc64 port?