How to speed up checksum computations of a string?

Here are the results on my Espruino board 1v4:

Mean execution time of nmea_checksum is 14.92417830008 ms,
Mean execution time of cks is 12.01456811692 ms,
Mean execution time of cks3 is 14.42750400967 ms,
Mean execution time of cks4 is 13.73525796113 ms,
Mean execution time of cks9 is 11.70109007093 ms,
Mean execution time of cks10 is 9.84849823845 ms,
Mean execution time of cks5 is 4.01897854275 ms,
Mean execution time of cks6 is 5.00975432219 ms,
Mean execution time of cks7 is 2.71540111965 ms

So finally, we have a benefit of 442 % in speed which is obviously reasonnable.
I joined the full source for this comparison.

Thank's again.

1 Attachment

• test_checksums.js