Cache both having run the dir check on the same element AND having run the selector on the same element in the same selection (best performance so far all around). Also run firstMatch combinators in a different function for less checks.
Cache both having run the dir check on the same element AND having run the selector on the same element in the same selection (best performance so far all around). Also run firstMatch combinators in a different function for less checks.

Related:
	http://jsperf.com/nwmatches-vs-modified-nwmatcher/12
	http://jsfiddle.net/timmywil/fS2rT/6
	http://jsfiddle.net/timmywil/fS2rT/9 (for comparing local to git)

mzgol/sizzle,npmcomponent/cristiandouce-sizzle