put-byte vs. setf get-byte

[djskrien@COLBY.EDU (Dale J. Skrien)]

I occasionally do some low-level byte moves and so was interested
to see Bill St. Clair post the following:

(setf (%get-byte macptr p-offset) (aref array a-offset))

Is this considered faster/better than:

(%put-byte macptr (aref array a-offset) p-offset)