> which got stuffed into the "general" extension family
No it didn't. That's why Linux Distributions say they are RV64GC, for general+compressed.
The original encoding set was done by Andrew Watermen to be implemented in the minimal amount of gates. And he was successful.
So of course any change would stick out like a sore thumb. That however does not mean its bad. For reasonable performance code cores it is well worth it because you get many benefits, not just code size. There is a reason that all systems that expect reasonable performance have adopted the C instruction as a standard, decoding is tiny part of the chip at that point.
Even some very tiny cores prefer as the price of slightly more decoder complexity is worth it compared to the code size.
I suggest you go look threw the lectures in the RISC-V channel, I have seen a number of presentation that do such comparison if I remember correctly.
No it didn't. That's why Linux Distributions say they are RV64GC, for general+compressed.
The original encoding set was done by Andrew Watermen to be implemented in the minimal amount of gates. And he was successful.
So of course any change would stick out like a sore thumb. That however does not mean its bad. For reasonable performance code cores it is well worth it because you get many benefits, not just code size. There is a reason that all systems that expect reasonable performance have adopted the C instruction as a standard, decoding is tiny part of the chip at that point.
Even some very tiny cores prefer as the price of slightly more decoder complexity is worth it compared to the code size.
I suggest you go look threw the lectures in the RISC-V channel, I have seen a number of presentation that do such comparison if I remember correctly.