| Field Name | Field bits | Description |
|------------|------------|----------------------------------------|
| ELWIDTH | `4:5` | Element Width |
-| PACK | `4` | Pack subvectors (sv.setvl only) |
-| UNPACK | `5` | Unpack subvectors (sv.setvl only |
| ELWIDTH_SRC | `6:7` | Element Width for Source |
| EXTRA | `10:18` | Register Extra encoding |
| MODE | `19:23` | changes Vector behaviour |
* MODE changes the behaviour of the SV operation (result saturation, mapreduce)
* SUBVL groups elements together into vec2, vec3, vec4 for use in 3D and Audio/Video DSP work
* ELWIDTH and ELWIDTH_SRC overrides the instruction's destination and source operand width
-* PACK and UNPACK apply to Subvector structure packing: may only be
- set by the `sv.setvl` instruction.
* MASK (and MASK_SRC) and MASKMODE provide predication (two types of sources: scalar INT and Vector CR).
* Bits 10 to 18 (EXTRA) are further decoded depending on the RM category for the instruction, which is determined only by decoding the Scalar 32 bit suffix.