K 10
svn:author
V 3
mjg
K 8
svn:date
V 27
2018-09-06T19:42:40.157361Z
K 7
svn:log
V 440
amd64: depessimize copyinstr_smap

The stac/clac combo around each byte copy is causing a measurable
slowdown in benchmarks. Do it only before and after all data is
copied. While here reorder the code to avoid a forward branch in
the common case.

Note the copying loop (originating from copyinstr) is avoidably slow
and will be fixed later.

Reviewed by:	kib
Approved by:	re (gjb)
Differential Revision:	https://reviews.freebsd.org/D17063

END