On 07/28/2010 08:45 AM, Linus Torvalds wrote: > On Tue, Jul 27, 2010 at 10:33 PM, tip-bot for H. Peter Anvin > <hpa@xxxxxxxxx> wrote: >> >> x86: Add memory modify constraints to xchg() and cmpxchg() > > Ack. I assume this doesn't really change the code generated? At least > not with a gcc that honors the whole memory clobber thing properly? > > I also suspect that we can/should get rid of the __xg() thing - it was > there just to make sure gcc didn't see the memory read as a single > word and tried to optimize it. With the "+m" it probably doesn't > matter any more (don't know if it ever did) > For what it's worth, it fairly heavily preturbs code around __set_64bit(), which implies it actually does something useful in that case. The rest of the code looks similar enough. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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