Glad to hear this. It would be fantastic if the VM would enable such experiment (e.g., relayouting variables and measuring impact on the low level cache).
Enjoy Splash! Cheers, Alexandre > On Oct 26, 2015, at 1:29 AM, Eliot Miranda <eliot.mira...@gmail.com> wrote: > > Hi Alexandre, > > On Fri, Oct 23, 2015 at 2:18 PM, Alexandre Bergel <alexandre.ber...@me.com> > wrote: > Hi! > > It is known that increasing data locality is a good way to benefit from CPU > caches. There has been some effort from the IBM’s JVM crew that aligns some > frequently accessed variables at a particular offset to improve accesses. > Would this approach works in Pharo? > > Other similar situation: will the expression “Object new yourself” be faster > if the object (i.e., result of Object new) is physically close to the class > Object in memory? > > Clément and I have discussed this issue. It's one significant advantage that > a conventional procedural language has over an OO one. Compare some > rendering pipeline that in its OO version has to traverse deep object > structure to dig out parameters as opposed to some array based implementation > where the parameters are extracted out into separate arrays and hence the > traversal is much simpler. > > I doubt that some minor rearrangement or alignment of structure would make > any difference. But imagine an adaptive optimizer for data structure that > could make the same transformation, automatically and invisibly to the > programmer. Such a general purpose optimizer would be far more powerful. > That's the kind of solution we think will be tried and that we would try if > we encountered such performance issues and we had time to address it. > > But I think this is beyond the current state of the art and it feels like a > PhD topic. I do remember Yoshiki saying that some plugin was doing something > similar, but I could be mistaken. > > > Cheers, > Alexandre > -- > _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: > Alexandre Bergel http://www.bergel.eu > ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. > > > > > > > -- > _,,,^..^,,,_ > best, Eliot -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
