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 Fields) then
+a simple branch-conditional test should be used instead.
+
# Pseudocode
// instruction fields: