Replying to myself. This has bothered me today. I think what I really wanted to say was: CPU vendors try to improve. The things they try to improve don't add u

Replying to myself. This has bothered me today. I think what I really wanted to say was: CPU vendors try to improve. The things they try to improve don't add up to "make bad code run fast", even if much of their motivation may be that. "Increase the number of instructions issued per cycle" or "improve the branch predictor" bends the effect towards code which is written with some awareness of the CPU, ie. good code. Bad code is IMO almost synonymous with code written without awareness.