something like:
-| 0 1 | 2 3 | 4 5 | 6 | 7 9 | 10 12 | 13 18 | 19 21 |
+| 0 1 | 2 3 | 4 5 | 6 | 7 9 | 10 12 | 13 18 | 19 20 |
| ----- | --- | --- | ---- | ---- | ----- | ----- | ----- |
| subvl | sew | dew | ptyp | psrc | pdst | vspec | sat |
these are of the form res = op(src1, src2, ...)
-| 0 1 | 2 3 | 4 5 | 6 | 7 9 | 10 18 | 19 21 |
+| 0 1 | 2 3 | 4 5 | 6 | 7 9 | 10 18 | 19 20 |
| ----- | --- | --- | ---- | ---- | ----- | ----- |
| subvl | sew | dew | ptyp | pred | vspec | sat |