On Mon, 2007-07-23 at 10:55 -0700, Linus Torvalds wrote: > > The goal is to let gcc generate good, beautiful, optimized code. > > No. The point is to let gcc generate *correct* code. > > It's either "=m" together with "memory", or it's "+m".
In fact, it's more than that... the bitops that return a value are often used to have hand-made spinlock semantics. I'm sure we would get funky bugs if loads or stores leaked out of the locked region. I think a full "memory" clobber should be kept around for those cases. (That's also why on ppc, we give them a few more barriers) Ben. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
