BTW: Which version of source code is canonical(deployed) one? There's "GetDecicsSrc" and then "Mingw64" and they differ.

So they should be the same. It's been a while, so I just did a quick look to refresh my memory. In the GetDecicsSrc directory there is a shell script called makeMingw64.sh which copies the source code into the Mingw64 directory and then invokes the make script for each gpu version. I suspect there may have been a minor change to the source code which never made it into the mingw64 build (redistributing all the apps for a small tweak is not necessarily a good idea in a stable project).

So the short answer to your question is that the code in the GetDecicsSrc directory is the "canonical" one.