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[RISC-V] [tech-privileged] P extension instruction opcode encoding allocation


mark
 

Krste has said (correct me if I am wrong) that the unpriv SC owns the opcode space. I know there is a lot of overlap in the SC members but I suggest we get that SC officially in the loop.

I have CC'ed them here. 

Unpriv SC, do you have a preferred process for proposing new instruction opcode space, format, etc.? If not, I suggest you establish one.

Mark


On Tue, Aug 11, 2020 at 2:30 AM Chuanhua Chang <chchang@...> wrote:

P extension instructions need to allocate opcode encoding space officially in the OP opcode space or other major opcode (such as reserved opcode).

What is the best way to decide on this and officially allocate encoding space for the P extension instructions?

 

Thanks.

 

Chuanhua


Allen Baum
 

Ken Dockser wrote a document on instruction encoding guidelines, but not the actual values of the minor/major opcodes, or sub-minor (functX) fields.
Attached
 

On Tue, Aug 11, 2020 at 7:33 AM mark <markhimelstein@...> wrote:
Krste has said (correct me if I am wrong) that the unpriv SC owns the opcode space. I know there is a lot of overlap in the SC members but I suggest we get that SC officially in the loop.

I have CC'ed them here. 

Unpriv SC, do you have a preferred process for proposing new instruction opcode space, format, etc.? If not, I suggest you establish one.

Mark


On Tue, Aug 11, 2020 at 2:30 AM Chuanhua Chang <chchang@...> wrote:

P extension instructions need to allocate opcode encoding space officially in the OP opcode space or other major opcode (such as reserved opcode).

What is the best way to decide on this and officially allocate encoding space for the P extension instructions?

 

Thanks.

 

Chuanhua