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When 16 bit computers went to 32 bit, people probably thought that one wouldn't ever need 64 bit computers either. That being said, by the time 128 bit run out
by est31 5y ago
When 16 bit computers went to 32 bit, people probably thought that one wouldn't ever need 64 bit computers either. That being said, by the time 128 bit run out we have probably boiled earths oceans :).
You could think of checked memory models where half of the 256 bit address is a 128 bit random key needed to access some allocation, or maybe even a decryption key. Similar things are done with the extra space of x64 as well.
Also, 128 bit numbers are still quite uncommon in Rust. Easy conversion of usize to them wouldn't be that useful if conversions of the other number types don't work.
- a1369209993 5y ago> When 16 bit computers went to 32 bit, people probably thought that one wouldn't ever need 64 bit computers either. People have said that about pretty much every memory size in the history of computing. The argument for 64-bit is not "2^64 bytes ought to be enough for anyone"; it's "you couldn't use more than 2^64 bytes even if you wanted to". Writing a full register worth of data every clock cycle at 4GHz works out to 32GB/s. (2^64B / 32GB/s) is just over seventeen years, to fill up a 64-bit address space, assuming you're doing no actual computation. Few computers even work for seventeen years without replacement, much less run single processes continually with no reboots.