| Field Name | Field bits | Description |
|------------|------------|----------------------------------------|
| ELWIDTH | `4:5` | Element Width |
+| PACK | `4` | Pack subvectors |
+| UNPACK | `5` | Unpack subvectoes |
| 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
* 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.
`RM-2P-2S` is for `stw` etc. and is Rsrc1 Rsrc2.
-## RM-2P-1S1D-PU
-
-| Field Name | Field bits | Description |
-|------------|------------|----------------------------|
-| Rdest_EXTRA2 | `10:11` | extends Rdest (R\*\_EXTRA2 Encoding) |
-| Rsrc_EXTRA2 | `12:13` | extends Rsrc (R\*\_EXTRA2 Encoding) |
-| PACK_en | `14` | Enable pack |
-| UNPACK_en | `15` | Enable unpack |
-| MASK_SRC | `16:18` | Execution Mask for Source |
-
-for [[sv/mv.vec]], [[sv/mv.swizzle]] and also LD/ST (without index)
-
## RM-1P-2S1D
single-predicate, three registers (2 read, 1 write)