[Bug rtl-optimization/50065] -Os, -O2, -O3 optimization breaks LD/ST ordering on 32-bit SPARC

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50065

--- Comment #5 from Mikael Pettersson <mikpe at it dot uu.se> 2011-08-14 
09:24:31 UTC ---
You need a _compiler_ barrier before the store in _unlock().