how far is SMP from being 64-bit clean?

Has any qualification been done on the SMP libraries for 64-bit environments?

I'm trying to build on SMP 2.5 on Fedora Core 3 x86_64, and although the build
reports no obvious problems, I get errors at run-time which on inspection seem to
be caused by the fact that there are some pieces of the code which are not 64-bit
clean.

For example:

SRL_db.c has:
    SRLi_FlipLongs(le_data, numbytes >> 2);

while the function definition in SRL_util.c is:
    void SRLi_FlipLongs(void *data, long numlongs)

i.e. SRL_db.c is assuming that a "long" contains 4 bytes.  Furthermore, inside
SRLi_FlipLongs(), there is various manipulation going on which also seems
based on the assumption that a "long" is made up of 32 bits.

A cursory look through the code suggests that there is quite a lot of usage of
"long"s, many of which appear to have similar problems.  So I wondered whether
there's anything going on with 64-bit ports, or whether anyone has a feel
for how pervasive these problems might be?

thanks

nick