4 ms·
The physical registers are not managed by the operating system. Instead they are used for out-of order speculation using register renaming: https://en.m.wikiped
by davidcme 4y ago
The physical registers are not managed by the operating system. Instead they are used for out-of order speculation using register renaming: https://en.m.wikipedia.org/wiki/Register_renaming https://en.m.wikipedia.org/wiki/Register_renaming
What you talk about is not used in the X86 ISA: https://en.m.wikipedia.org/wiki/Register_window https://en.m.wikipedia.org/wiki/Register_window
If PS5 code uses fewer floating point operations than conventional desktop CPUs, there are fewer physical floating point registers needed for an equally sized speculation window.
- kevingadd 4y agoIt would make sense if PS5 games don't have as much of a need to do floating point work on the CPU, since they have shared-memory access to a high-performance GPU and can do pretty much anything they want with it. AFAIK AMD has had asynchronous GPU compute support in their hardware for a long time, so I'm sure the chip in the PS5 has it.
- Narishma 4y agoEven the PS4 supported async compute in its GPU.
- tredre3 4y agoRegister window isn't used for context switching, it's used during function calls. In most architectures the sliding is done implicitly during by the call/ret instructions (named eg call4 ret4 to slide 4). Some architectures allow you to also slide the window manually but none (that I know of) allows you the absolute positioning needed to mimic traditional register files/banking.