Re: Stealing a Great Idea from the 6600

On Fri, 19 Apr 2024 18:40:45 +0000, mitchalsup@aol.com (MitchAlsup1)
wrote:

So how does a 32-register thread "call" an 8 register thread ?? or vice
versa ??

That sort of thing would be done by supervisor mode instructions,
similar to the ones used to start additional threads on a given core,
or start threads on a new core.

Since the lightweight ISA has the benefit of having fewer registers
allocated, it's not the same as, slay, a "thumb mode" which offers
more compact code as its benefit. Instead, this is for use in classes
of threads that are separate from ordinary code.

I/O processing threads being one example of this.

The intent of this kind of lightweight ISA is to reduce the temptation
to decide "oh, we've got to put special smaller cores in the SoC/on
the motherboard to perform this specialized task, because the main CPU
is overkill". Because now you're using a smaller slice of the main
CPU, so it's not a waste to do it there any more.

John Savard