Re: Byte Addressability And Beyond

On Fri, 03 May 2024 08:51:30 GMT
anton@mips.complang.tuwien.ac.at (Anton Ertl) wrote:

Lawrence D'Oliveiro <ldo@nz.invalid> writes:

On Thu, 02 May 2024 17:37:47 GMT, Anton Ertl wrote:
 

... MIPS has left the general-purpose computing field. 

>
Not so sure that it has. I think the Chinese “LoongArchâ€_
machines are a MIPS derivative. 

 
They may have started with MIPS, like several others, but now they are
LoongArch.  Looking in
<https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#common-memory-access-instructions>,
I don't find anything about byte order, but it says:
 
|LoongArch bit designations are always little-endian.
 

Also, if you want to think of “MIPSâ€_ as a corporate entity, that
would be the company currently known as “Imagination
Technologiesâ€_. It is true they have given up on the MIPS
architecture 

 
That's even worse for MIPS than what I know of, which was that it was
used for embedded uses.
 
- anton

My impression was that embedded MIPS had two main players behind it:
- Microchip on the low end. Measured on Arm scale from about Cortex-M3
class to Cortex-M7 class.
- Cavium on the high end. From Cortex-A55 to not quite Cortex-A73.

Microchip will continue to sell it for decade at least. Microchip does
not tend to talk openly about directions, however their behavior shows
that their direction right now is away from MIPS and currently toward
Arm.

Cavium was absorbed by Marvell sevral years ago. Marvell, like
Microchip, does not tend to talk openly about directions. But when
Cavium was still independent, they did say that all new development
would be Arm.  Since Cavium's market (high-end nework equipment) is less
conservative and more fashion-driven, it probably means that they have
no new MIPS customers almost for decade and that old customers likely
buy much less as well.

As far as I am concerned, it's a pity, because I find MIPS latest ISA
(nanoMIPS) very intersting and probably quite practical.