[icebraining]

Why? If you're running a system with PAE, half of a 32-bit address space is a small fraction of the whole addressable memory.

[loeg]

It's either addressable or it isn't. My understanding of typical PAE systems is that userspace is still limited to 32 bits of address space per process. Any system where userspace is not limited to 32 bits should have a larger than 32-bit size_t. (PAE systems are not true 32-bit platforms.)