which instruction is quicker?

or

It should be measured but since they differ in a single bit (direction bit) and are converted to a set of RISCy micro-ops by the processor, I guess, the two are equal in speed. For quite strict definitions of equality.

Measure it. Do you see any difference? If it it really important for you to know which is "quickest" then you will need to measure both variants in your production code to determine which variant works for you.

Other people here could run some test code on their systems, but this is unlikely to give you any useful information about what will happen in your code on your systems.