| 0-1 | 2 | 3 4 | description |
| --- | --- |---------|-------------------------- |
| 00 | 0 | dz sz | simple mode |
-| 00 | 1 | 0 RG | scalar reduce mode (mapreduce), SUBVL=1 |
-| 00 | 1 | SVM 0 | subvector reduce mode, SUBVL>1 |
-| 00 | 1 | / 1 | reserved |
+| 00 | 1 | 0 RG | scalar reduce mode (mapreduce) |
| 01 | inv | CR-bit | Rc=1: ffirst CR sel |
| 01 | inv | VLi RC1 | Rc=0: ffirst z/nonz |
| 10 | N | dz sz | sat mode: N=0/1 u/s |
* **inv CR bit** just as in branches (BO) these bits allow testing of a CR bit and whether it is set (inv=0) or unset (inv=1)
* **RG** inverts the Vector Loop order (VL-1 downto 0) rather
than the normal 0..VL-1
-* **SVM** sets "subvector" reduce mode
* **N** sets signed/unsigned saturation.
* **RC1** as if Rc=1, stores CRs *but not the result*
* **VLi** VL inclusive: in fail-first mode, the truncation of