EQUIVALENCE statements are not handled
In general Fortran
EQUIVALENCE statements aren't handled at all by f2cl, but there are cases where f2cl should be able to convert to Lisp.
EQUIVALENCE just aliases a bunch of variables and arrays together and they are all of the same basic type, f2cl should be able to create a giant array and map the variables and arrays at the appropriate locations in the array. F2cl cannot do that currently, except in some very simple cases.