3 ms·
> But yes, register count is still a thing. Why? If you run out of registers, operations 'spill out' into main memory. Read: L1 (data) cache. Which is fast, but
by anon-3988 2mo ago
> But yes, register count is still a thing. Why? If you run out of registers, operations 'spill out' into main memory. Read: L1 (data) cache. Which is fast, but not as fast as CPU registers. And probably uses a lot more transistors & power.
Yes, register renaming. What I mean is that why does anyone care still what instruction I am running on? The CPU have its own microops, instruction decoder, its own pipeline, scheduler, etc etc
Why can't you have a CPU that have 1024 registers and pretend that it only have 32?
- peterfirefly 2mo ago1024 is stretching it a bit but several hundred are normal for high-end CPUs -- while pretending to have 32 (+ usually 32 SIMD registers that may or may not overlap with the normal 32). "[...] and pretend that it only have [sic] 32" is EXACTLY what register renaming is.