To those of you who haven't made a CPU before: CPU technology is more like a javascript framework than a natural resource. When someone says "block China from US CPU ISAs" think "block China from US javascript frameworks". Then you'll have the appropriate sense of how silly it is.
If javascript frameworks is patented then yes, you can. For reference ARM big little scheduler is patented[1], you need to license from ARM if you use any of their big little design. RISC-V under BSD license might change this.
Because that would result in a more devastating response from the side that holds patents. If china stops respecting international trade laws and agreements, other nations will hurt china's interests in return. Given the scale of the things, the weak spots will be found inevitably.
There is a difference. Nobody in the first world really cares about Uighurs or Hong Kong. However, there are quite a handful of parties who do care about patents (and resulting profits).
China has been pilfering intellectual property from labs & private companies via APTs for the last couple of years: what are the handful of parties who care about patents going to do - write a strongly worded letter? If China decides it wants to get the latest ARM design and/or ISA in the future, do you doubt they can acquire them? Sure, they won't be able to call it "ARM" but you can bet it will be compatible[1].
For internal market, no, but they will have problems selling the pirate copies to the rest of the world. Most rich states do respect intellectual property.
(1) What you linked does not appear to be an ARM patent. (2) Even if it were, lack of big/little scheduling is hardly going to bring China's homegrown chip market to it's knees. And that's assuming the patent is ironclad and can't be worked around.
I haven't made CPUs before ( I am guessing you have?), so I am not sure of what you are implying. Are you saying that CPU technology is as easy or copy-able like a javascript framework? I can see that ISA would be copy-able. But what about a modern implementation?
CPU design is a mature field that has been studied extensively. I've thrown together a few toy CPUs, and studied some F/OSS RISC-V designs. New tricks are still being developed for modern software workloads and modern constraints (low-power is key now, whereas before other things might have been priority), but architecture things really haven't changed much since the 90s.
My comparison with JS frameworks comes from my perception that CPU designs are all, kinda, the same. There are also a million ways to do things, but the core principles are obvious to people who study CPU design.
