On Sat, 29 May 1999 09:30:20 -0400 
 Bill Sommerfeld <sommerfeld@orchard.arlington.ma.us> wrote:

 > Besides what I wrote about PA requiring 16-*byte* alignment for
 > semaphores, I'd imagine that at least some LP64 systems would have
 > difficulty atomically setting a 32-bit object.

The Alpha, at least, can do "atomic" operations (via load-locked and
store-conditional) on both of the architectures "native" word sizes,
32-bit and 64-bit (i.e. ldl_l/stl_c and ldq_l/stq_c).

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>