PaulHoule 18 minutes ago

If you were interested in co-designing a CPU with software the TTA is an attractive way to do it, particularly in that it is easy to design it so you can do more than one MOV at the same time and thus have explicit parallelism.

The tough part though is that memory is usually slow and you have to wait an undetermined number of cycles for data to get back from DRAM and while one operation is blocked all the other operations are blocked.

I guess you could have something like this with a fancy memory controller that could be programming explicitly to start fetching ahead of time so data is available when it is needed, at least most of the time.

gsliepen 3 hours ago

The Intel architecture is already Turing complete when you just use MOV instructions: https://github.com/xoreaxeaxeax/movfuscator. Of course, you don't even need instructions at all: https://news.ycombinator.com/item?id=5261598

  • QuadmasterXLII an hour ago

    While this is true, I suspect a spec compliant implementation of the x86 mov instruction would many use more transistors than OP’s entire CPU.

    • crest 25 minutes ago

      Of course, but you don't have the toy CPU under your desk or in your laptop running at several GHz nor are you likely to find it in a target that really needs a cute hack to obscure your exploit.

psychoslave 2 hours ago

Looks like an interesting read, thank you @v9v.

Just when my night was going through a meditative sleep about basing ontological models using change as fundamental block. Identity is such a brittle choice as foundation, even if it's a great tool in many situations otherwise.

  • pyinstallwoes 3 minutes ago

    Many ancient cultures use behavior as identity. It certainly has a charm.