[MisterAV]

Having 32-bit pointers doesn't mean that ASLR becomes much less effective? I can suppose that for V8 is not a big problem, because they use compressed pointers where necessary, but if it was a compiler directive (like Knuth wanted) it would affect the whole program. I would not use that option for any program that have to process untrusted input.

[verwaest]

It does: pointers in the V8 heap all lie within the same 4gb region. But then again, Spectre also makes ASLR much less effective.