[knz42]

Yes you are right, if that was marketed like the introduction of x64 it may work.

However there is a big difference: the move to 64-bit words was something that was in demand when it was introduced. There was a market for it, with a very clear value proposal.

In contrast a new "mode" with the same computational power plus dataflow annotations would be a tough sell: larger code size, and and better performance / watt only for some applications.

(Also, as far as I know AMD64 / x64 on Intel cores uses the same decode and issue unit, just with different microcode. Circuit-wise there is a lot in common with x86.

Here we would be talking about a new mode and also a new instruction+data path in the processor. The core would become larger and more expensive. Not sure how that plays.)

[jacques_chester]

Is there something about dataflow annotated instructions that would require lots of internal changes? I mean past the decoding step. Because Intel and AMD add new instructions and modes all the time, frequently stuff that is basically totally orthogonal to whatever's gone before.