Mostly yes: usual cryptographic operations, including hashes,
are defined using operations on integers and bit vectors, not
Floating Point Numbers. I think the main reason is that in
cryptography, we need different computers (e.g. the one that
hashes a file to protect its integrity, and the one that
verifies the integrity) to get the exact same result, and that
is hard to ascertain for Floating Point operations.
Historically, computers used different format and precision for
representing Floating Point numbers, and that would cause huge
portability problems. Nowadays virtually every recent CPU with
FP support (which is only a tiny fraction of the CPUs
manufactured) can use at least one of the 32-bit, 64-bit or
128-bit format of IEEE 754, so this is slightly less a concern
than it was. But still, many computer languages and dialects
give no way to precisely control rounding, or to efficiently
convert arbitrary information as found in a generic file into FP
format and back. It remains a mess to even get exactly