smp: Make code that encodes identities more readable

smp: Make code that encodes identities more readable

In particular for static code analyzers.  The previous nesting of case
statements inside of a while loop that's inside a switch statement and
a wrapping block with declaration was quite weird and Coverity didn't
like it (it figured that `type` was uninitialized even when it assumed
that get_type() returned a known type for which a case statement
existed).