The intrinsics are universally available, whereas older Windows SDKs (e.g.
7.0.7600) don't have the non-intrisic entrypoint.
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
It was totally broken:
- p_atomic_dec_zero() was returning the negation of the expected value
- p_atomic_inc_return()/p_atomic_dec_return() was
post-incrementing/decrementing, hence returning the old value instead
of the new
- p_atomic_cmpxchg() was returning the new value on success, instead of
the old
It is clear this never used in the past. I wonder if it wouldn't be better to
yank it altogether.
Reviewed-by: Matt Turner <mattst88@gmail.com>
like how C11's stdatomic.h provides generic functions. GCC's __sync_*
builtins already take a variety of types, so that's simple.
MSVC and Sun Studio don't, but we can implement it with something that
looks a little crazy but is actually quite readable.
Thanks to Jose for some MSVC fixes!
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
