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Actually it does https://queue.acm.org/detail.cfm?id=3212479 https://queue.acm.org/detail.cfm?id=3212479 "The root cause of the Spectre and Meltdown vulnerabi
by tored 5y ago
Actually it does
https://queue.acm.org/detail.cfm?id=3212479 https://queue.acm.org/detail.cfm?id=3212479
"The root cause of the Spectre and Meltdown vulnerabilities was that processor architects were trying to build not just fast processors, but fast processors that expose the same abstract machine as a PDP-11. This is essential because it allows C programmers to continue in the belief that their language is close to the underlying hardware."
- will4274 5y agoJava exposed the same abstract machine as a PDP-11 too. The key "PDP-11" thing is that all memory is treated as equally accessible, rather than the reality - i.e. that some memory is in caches on certain cores only and can therefore be accessed more efficiently on those cores.
- bruce343434 5y agoJust because an academicist has an opinion does not make it fact. That quote reads like a blogpost and with its lack of citation it might as well be. Yes, it sounds plausible. but well. Let's assume it's true: your argument would be "intel made a mistake, but since they would have only made that mistake when doing stuff that appeases C programmers (would they have?), it's actually because of C." Now, I think this is a bit of a stretch. ETA: or did you mean that it has to do with C for that reason? in which case, ok, I see how you mean.
- verall 5y agoOh yea, if not for emulating the PDP-11, processor designers would have no interest in instruction level parallelism. This article is pretty funny actually: > On a modern high-end core, the register rename engine is one of the largest consumers of die area and power. To make matters worse, it cannot be turned off or power gated while any instructions are running Yea, let's just gate off the RAT. What's it for again?