Here's 2 base64 machine code functions I wrote that came out pretty good. Both encode and decode are x64 capable. Comparing times for encoding/decoding the autoit.exe with Microsofts functions, I got them beat by a good percentage for both x84/x64 decode functions. I'm pretty sure thats due to my reverse index idea. It ended up working very well.  I beat there x86 encode by a little bit, but they got me beat by just a hair for x64 encode. The attachment includes example that has the time tests I