[Libre-soc-dev] results of phone call about simple-v prefix

Cole Poirier colepoirier at gmail.com
Fri Nov 27 23:30:04 GMT 2020

On Friday, November 27, 2020, Jacob Lifshay <programmerjake at gmail.com>
> Turns out that primary opcode 0 is used for implementation-specific
> opcodes. primary opcode 1 and 5 are defined to cause illegal instruction
> traps for the encodings we want to use. We could potentially move to using
> primary opcode 6 for 32/48-bit instructions -- 1/8 is currently used (new
> in v3.1), the rest causes illegal instruction traps. This would reduce the
> space for svp32 somewhat, svp48 would have just as much space as before.

Isn’t this behaviour for PO 0, 1, 5 exactly what we were hoping for?


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