+-----------+-------------+---------------------------+------------+----------------------+
| 0 | imm | 000 | rs'!=0 | sv.setvl immed mode |
+-----------+-------------+---------------------------+------------+----------------------+
-| 0 | imm | rd'!=0 | 000 | not sure |
+| 0 | imm | rd'!=0 | 000 | not sure. reserved? |
+-----------+-------------+---------------------------+------------+----------------------+
| 0 | imm | rd'!=0 | rs'!=0 | sv.setvl rd, rs, MVL |
++-----------+-------------+------------+--------------+------------+----------------------+
+| 1 | imm | 0 | 00 000 | set MVL immed |
++-----------+-------------+------------+---------------------------+----------------------+
+| 1 | imm | 0 | rd[4:0] | sv.setvl rd, immed |
+-----------+-------------+------------+---------------------------+----------------------+
-| 1 | imm | 0 | 00000 | set MVL immed |
+| 1 | imm | 1 | 00 000 | something. reserved? |
+-----------+-------------+------------+---------------------------+----------------------+
-| 1 | imm | 1 | rd[4:0] | sv.setvl rd, immed |
+| 1 | imm | 1 | rs1[4:0] | set MVL rs1? |
+-----------+-------------+------------+---------------------------+----------------------+