bit-slice and microcode discussion list
elson at pico-systems.com
Fri Aug 23 21:05:14 CDT 2019
On 08/23/2019 12:47 PM, Noel Chiappa via cctalk wrote:
> > From: Jon Elson
> >> On 08/22/2019 12:47 PM, Tom Uban via cctalk wrote:
> >> On a possible related note, I am looking for information on converting
> >> CISC instructions to VLIW RISC.
> > I think it might end up looking a bit like the optimizers that were
> > used on drum memory computers back in the dark ages.
> I dunno; those were all about picking _addresses_ for instructions, such
> that the next instruction was coming up to the heads as the last one
Right, but the idea is to schedule memory reads way in
advance of when the datum is required for a calculation.
So, the load from memory to register is moved way up in the
program, and the use of the register is much later to allow
for the memory latency. Yes, it is not exactly like drum
memory computers, but you are still scheduling things for
when they can be done without causing a stall.
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