3 ms·
And then there are CPUs that retcon behavioral changes onto nops. > Moving a register to itself is functionally a nop, but the processor overloads it to signal
by tedunangst 3y ago
And then there are CPUs that retcon behavioral changes onto nops.
> Moving a register to itself is functionally a nop, but the processor overloads it to signal information about priority.
https://devblogs.microsoft.com/oldnewthing/20180809-00/?p=99455 https://devblogs.microsoft.com/oldnewthing/20180809-00/?p=99...
- _a_a_a_ 3y ago> A program can voluntarily set itself to low priority if it is waiting for a spin lock What does this even mean? How can a program do this when thread priority is an OS thing? It's seems just weird.
- epcoa 3y agoHardware threads as in SMT means thread priority is also a hardware thing.
- tedunangst 3y agoIt's an SMT CPU that dynamically assigns decode, registers, etc. https://course.ece.cmu.edu/~ece740/f13/lib/exe/fetch.php?media=kalla04_power5.pdf https://course.ece.cmu.edu/~ece740/f13/lib/exe/fetch.php?med...