4 ms·
Bear in mind the patent was filed in 1996 when considering the level of innovation.
by timthorn 11y ago
Bear in mind the patent was filed in 1996 when considering the level of innovation.
- masklinn 11y agoThere were branch-predicting mainframes back in the 80s, though it really came to the fore with the advent of superscalar microprocessors in the early 90s (MIPS R8000 and DEC Alpha 21064), what is the paper's innovations above these?
- matthewmacleod 11y agoIt's pretty clear from even a cursory look – the patent covers a second level of branch prediction, where the processor determines whether or not it should bother speculatively executing an instruction based on the previous outcome of that speculative execution. Whether or not there was a prior implementation of this, I don't know – but it's also obviously more than a simple saturating counter branch predictor or whatever.
- sitkack 11y agohttp://www.theonion.com/blogpost/fuck-everything-were-doing-five-blades-11056 http://www.theonion.com/blogpost/fuck-everything-were-doing-... So inductive patent expansion. Take previous innovation, add 1, profit. What about L0 and L4 caches? Or Renaming sets of renamed registers? The problem as others have outlined, that patents are not concrete enough. Simply describing a problem is enough to be granted a patent. The value of the description of most patents is zero, which afaik this opposite of their intended effect as a record and transfer of technology.
- mzs 11y agoNone of those processors had anything like this. The innovation of the UWM paper was the MDPT and DDST, then due to practical manufacture reasons merging them, and then studying the trade-off with a simulator to arrive at a very efficient system. For comparison, here is the IBM patent for the bigger more expensive approach used in Power4: http://www.google.com/patents/US5615350 http://www.google.com/patents/US5615350
- wsxcde 11y agoThis is not even related to branch prediction, it is a scheme for controlling load speculation. This means executing a load out of order, even if there are stores with unresolved addresses ahead of it. This paper isn't proposing load speculation, it's proposing a predictor when for when it should be done.
- samfisher83 11y agoHaving a look up table for branch prediction? If something happens a lot it might happen in the future. That doesn't even sound that novel.