Many thanks for the comprehensive answer. I hadn't actually considered how I defined "speculative execution". I suppose what I meant is a cpu which will execute

Many thanks for the comprehensive answer. I hadn't actually considered how I defined "speculative execution". I suppose what I meant is a cpu which will execute more than one path in a branch and discard those branches which are not taken. Either way, I was expecting the answer to be something like the AMD hammer or something around there. Clearly off by a bit :)