Comment by moonchild

depends how you define causality. if you consider the execution of one operation to cause the execution of the next operation in program order, then causality was already broken by simple reordering. if it's a read-write dependency, on the other hand, then it won't be broken (because cpus respect control dependencies); hence, you cannot, for example, replicate oota this way. what's broken is specifically read-read data dependencies. and only on weakly-ordered architectures; it won't do anything on x86