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That's a ways out. We're not even using all bits in addresses yet. Unless they want hardware pointer tagging a la CHERI there's not going to be a need to incre
by SAI_Peregrinus 8mo ago
That's a ways out. We're not even using all bits in addresses yet. Unless they want hardware pointer tagging a la CHERI there's not going to be a need to increase address sizes, but that doesn't expose the extra bits to the user.
Data registers could be bigger. There's no reason `sizeof int` has to equal `sizeof intptr_t`, many older architectures had separate address & data register sizes. SIMD registers are already a case of that in x86_64.
- hinkley 8mo agoYou can do a lot of pointer tagging in 64 bit pointers. Do we have CPUs with true 64 bit pointers yet? Looks like the Zen 4 is up to 57 bits. IIRC the original x86_64 CPUs were 48 bit addressing and the first Intel CPUs to dabble with larger pointers were actually only 40 bit addressing.
- Joker_vD 8mo ago> There's no reason `sizeof int` has to equal `sizeof intptr_t` Well, there is no reason `sizeof int` should be 4 on 64-bit platforms except for the historical baggage (which was so heavy for Windows, they couldn't move even long to be 64 bits). But having an int to be a wider type than intptr_t probably wouldn't hurt things (as in, most software would work as-is after simple recompilation).