# alternative 32-64 encoding
```
-| 0-5 | 6-28 29 | 30-31| 32 |33-63| Description |
-|-----|---------|------|----|-----|------------------------------------|
-| PO9 | xxx | 0 | 0 0 | 000000 xxxx 000 | SVP64:EXT900 |
-| PO9 | xxx | 1 | 0 0 | 32-bit EXT900 |
-| PO9 | !zero | 0 0 | 1 | DWd | SVP64Single:EXT232-263 |
-| PO9 | 0000 | 0 0 | 1 | DWd | Scalar EXT232-263 |
-| PO9 | nnnn | 1 0 | 1 | DWd | SVP64:EXT232-263 |
-| PO9 | 0000 | 0 1 | x | xxxx| 32-bit Unvectorizable (in 64-bit) |
-| PO9 | !zero | 0 1 | n | DWd | SVP64Single:EXT000-063 |
-| PO9 | nnnn | 1 1 | n | DWd | SVP64:EXT000-063 |
+| 0-5 | 6-28 29 |30-31| 32 |33-37| 38-60 | 61-63 | Description |
+|-----|---------|-----|----|-----|-----------------------------------|
+| PO9 | xxx | 0 | 0 0 | 0 00000 xxxx 000 | SVP64:EXT900 |
+| PO9 | xxx | 0 | 0 0 | !zero xxxx !zero | 55-bit RESERVED |
+| PO9 | xxx | 1 | 0 0 | 32-bit EXT900 |
+| PO9 | !ZERO | 0 0 | 1 | DWi | SS:EXT232-263 |
+| PO9 | 0000 | 0 0 | 1 | DWi | Scalar EXT232-263 |
+| PO9 | nnnn | 1 0 | 1 | DWi | SVP64:EXT232-263 |
+| PO9 | 0000 | 0 1 | Defined Word-instruction | 32-bit Unvec in 64b|
+| PO9 | !ZERO | 0 1 | Defined Word-instruction | SS:EXT000-063 |
+| PO9 | nnnn | 1 1 | Defined Word-instruction | SVP64:EXT000-063 |
```
Length detection: