target The remotely accessible short data object to be updated on the
remote PE. When using C/C++, the type of target should match that
implied in the SYNOPSIS section.
cond cond is compared to the remote target value. If cond and the remote
target are equal, then value is swapped into the remote target;
otherwise, the remote target is unchanged. In either case, the old
value of the remote target is returned as the routine return value.
cond must be of type short.
value The value to be atomically written to the remote PE. value is of
type short.
pe An integer that indicates the PE number on which target is to be
updated.