__cxa_guard_release's Return Value Means ???

["Jeffrey D. Oldham" <oldham@xxxxxxxxxxxxxxxx>]

In \S 3.3.2 of the C++ ABI for IA-64
(http://reality.sgi.com/dehnert_engr/cxx/abi.html) specifies

  extern "C" int __cxa_guard_release ( long long *guard_object );

  The guard_object argument is the guard variable (see Section 2.8)
  associated with the object being initialized. Set it to indicate
  that initialization is complete, release the associated lock (in
  that order), and return.

What should the integral return value of the function be?  Should the
function be a void function?

Thanks for the informtion,
Jeffrey D. Oldham
oldham@xxxxxxxxxxxxxxxx