is to be considered as if the "single element". Caveats exist for
[[sv/mv.swizzle]] and [[sv/mv.vec]] when Pack/Unpack is enabled.
-**Predicate Masks**
-
-Registers used as Predicate Masks must *never* be altered by *any*
-instruction when Vertical-First is active. If more than the available
-predicate registers are required (r3, r10, r30, CR Predicate Fields) then
-because Vertical-First is not that different from executing standard
-Scalar instructions,
-a simple branch-conditional test should be used instead of predication,
-exactly as would normally be done if SVP64 was not in use.
-Alternatively the `setvl` instruction may be called again with the `vf`
-flag set. This tells the hardware to re-assess the use of Predicates
-
-These rules allow Hardware implementors to choose to
-free up the connection
-between registers used as predicates and registers used for standard
-purposes: Hazards need not be created.
-
-Note that each of the registers may each be used as predicates,
-or they may be used for standard normal purposes. If mixed for
-both purposes when Vertical-First is active, the results of execution
-is `UNDEFINED`.
-
# Pseudocode
// instruction fields: