uiop: Remember single/multi-threaded in the implementation-identifier.
I'm comparing performance for single- and multi-threaded builds.
The FASL files for SBCL are dependent on ST/MT, though; so I can't just switch the SBCL binary and re-test, because the FASLs are incompatbile, get rejected, and need to be recompiled every time.
I have a proof-of-concept patch at https://github.com/sbcl/sbcl/commit/1269dab756151b4d8c6347a0ca52e83b7926a68e that adds the ST/MT information to the implementation-identifier - then the FASLs land in different trees, and the binary just chooses the matching files.
I'm not sure whether the string `"singlethreaded"` is too long, as it gets added to the tree structure depth which is limited to 255 characters - but it's at least a starting point for discussion.
issue