# Data-dependent fail-first on CR operations
+The principle of data-dependent fail-first is that if a Condition Test
+fails then VL (Vector Length) is truncated at that point. In the case
+of Arithmetic SVP64 Operations the Condition Register Field generated from
+Rc=1 is used, however with CR-based operations that CR result is provided
+by the operation itself. In some cases however, CR-based operations
+operate on entire CR fields, not just one bit.
+
Data-dependent SVP64 Vectorised Operations involving the creation or
-modification of a CR require an extra two bits, which are not available
+modification of a CR can require an extra two bits, which are not available
in the compact space of the `MODE` Field. With the concept of element
width overrides being meaningless for CR Fields it is possible to use the
`ELWIDTH` field for extra fields.