SIMD strncpy hand-written assembly routines are, to be blunt about it, a total nightmare. 240 instructions is not uncommon, and the worst thing about them is that they are unable to cope with detection of a page fault condition.
+Note: see <https://bugs.libre-soc.org/show_bug.cgi?id=561>
+
# Data-dependent fail-first
This is a minor variant on the CR-based predicate-result mode. Where pred-result continues with independent element testing (any of which may be parallelised), data-dependent fail-first *stops* at the first failure: