More or less the conclusions I came to during university. Speculative execution felt dicey (because you're doing things before you know if they are the right th

More or less the conclusions I came to during university. Speculative execution felt dicey (because you're doing things before you know if they are the right things), so I spent some time thinking about it and realised that you are (basically) throwing away or rolling back the erroneous execution. At worst I thought it would be wasted executions if, e.g, your branch predictor is poor - I never even thought about timing or indirect attacks. It's a pretty subtle thing IMO. IIRC, one of my professors at one point explained modern CPU behaviour (branch prediction/OOOE etc.) as, roughly, the CPU can do whatever it likes because the program never sees what happened under the hood - it just has to order the result/make sure the result is correct.