alt Hacker NewsSeriously though, I’ve been wondering for a while whether I could build a GCC for x86-64 that would have 32-bit (low 4G) pointers (and no REX prefixes) by default and full 64-bit ones with __far or something. (In this episode of Everything Old Is New Again: the Very Large Memory API[1] from Windows NT for Alpha.)
[1] https://devblogs.microsoft.com/oldnewthing/20070801-00/?p=25...
Replies
dajtxx • today at 12:52 AM
6502 zero page instruction vibes.
A moderate fraction of the work is already done using:
https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html
Unfortunately the obvious `__attribute__((mode(...)))` errors out if anything but the standard pointer-size mode (usually SI or DI) is passed.
Or you may be able to do it based on x32, since your far pointers are likely rare enough that you can do them manually. Especially in C++. I'm pretty sure you can just call "foreign" syscalls if you do it carefully.