On Thu, 2014-02-20 at 10:11 -0800, Paul E. McKenney wrote: > But yes, the compiler guys would be extremely happy to simply drop > memory_order_consume from the standard, as it is the memory order > that they most love to hate. > > Getting them to agree to any sort of peep-hole optimization semantics > for memory_order_consume is likely problematic.
I wouldn't be so pessimistic about that. If the transformations can be shown to be always correct in terms of the semantics specified in the standard, and if the performance win is sufficiently large, why not? Of course, somebody has to volunteer to actually implement it :)
