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.