* Paul Schlie: >> People always say this, but they don't really realize what they are >> saying. This would mean you could not put variables in registers, and >> would essentially totally disable optimization. > > - can you provide an example of a single threaded program where the > assignment of variable to a machine register validly changes its > observable logical results?
Here's the usual suspect: <http://gcc.gnu.org/PR323> Although the "validly" part is somewhat debatable.