K 10
svn:author
V 6
kevans
K 8
svn:date
V 27
2019-10-02T17:08:20.586804Z
K 7
svn:log
V 206
sparc64: use generic sub-word atomic *cmpset

Most of this diff is refactoring to reduce duplication between the different
acq_ and rel_ variants.

Differential Revision:	https://reviews.freebsd.org/D21822

END