SLONG is stored in dsql_nod* (nod_arg).
To put data in it,
nod_arg = (dsql_nod*) (IPTR) number;
is used. I will not talk here about all casts, pure SLONG passes through to reach it's permanent location, it's not important here. But extraction is done in desc style. ie:
SLONG value = * (SLONG*) nod_arg;
This seems to be OK, and it's really OK for any 32-bit machine and for any little endian machine. On 64-bit big endian CPU 32-bit data is placed in one half of a 64-bit pointer, but taken from another one.
This ticket is only about dsql_nod, but there are may be more such places in the engine.