This tool can be used to generate dll's for any list of object files
given to it. It will then repartition them automatically to fit within
a dll and generates as many dll's as needed to do this. Cyclic dependencies
between these generated dlls are handle automatically so there is no need
to tell it how to partition.
It is also a lot more general than dll-split as it is able to split any
package not just libGHC. It also uses a trick using GNU style import libraries
to hide the splitting from the rest of the pipeline. Which means come linking time
you don't need to know which dll contains what symbol or how many split dlls were
The import libraries are by default created with libtool. However since libtool is BFD
based it is very slow. So if present and detected by configure the genlib tool
from the msys2 project is used. This makes a difference of about ~45 minutes when compiling.
To install genlib run pacman -Sy mingw-w64-$(uname -m)-tools-git.
More detailed explaination of the process can be found here