The reason for the improvements when you fixed the truncations is that indexing with a float is deprecated and calling deprecated methods is very slow. For good performance it is therefore important not to repeatedly call any deprecated method.
@inbounds is good if you have a very tight loop with many vector loads (like in your example). Remember that @inbounds turns off bounds checking so if you mess up you can segfault or get garbage data. For parallellization I would look at shared arrays: http://julia.readthedocs.org/en/latest/manual/parallel-computing/#shared-arrays On Sunday, October 11, 2015 at 11:28:08 PM UTC+2, Alain Clo wrote: > > Pretty good improvements Thanks to you Kristoffer. > I am puzzled why the changes on the truncations for sxloc and szloc brings > a factor of 3 to the whole program, > to the loop underneath. Maybe the truncation changed the indexing type to > the whole array, right ? > How did you figure out this affect ? > > Regarding @inbounds and @fastmath. I have the same question, but I see > them now in the performance tips. > Maybe as a generic rule, those options have to be checked. > > Would you have any suggestions for parallelisation ? > > Thanks for the feedback > Alain > > > > > Le dimanche 11 octobre 2015 23:48:55 UTC+3, Kristoffer Carlsson a écrit : >> >> Some unsolicited comments on the code. >> >> You probably want to change line 118 and 119 to >> >> sxloc = trunc(Int, mxnx / 2) >> szloc = trunc(Int, mxnz / 2) >> >> so that they really are ints, Without the "Int" it will still be a float. >> >> As a base line, your code for me ran in 1.239 seconds. >> >> Adding "@inbounds" on line 127 takes this down to 0.75 seconds. >> >> Adding "@fastmath" on the same line reduces it further down to 0.52 >> seconds. Normal caveats for fastmath of course applies. >> >> // Kristoffer >> >> >> >> On Sunday, October 11, 2015 at 9:32:04 PM UTC+2, Alain Clo wrote: >>> >>> See attached the updated code ( slight modifications, code embedded into >>> a function acoustic(), and some loops interchanged). >>> To see some images, uncomment at the end of the code. >>> Enjoy ! >>> Alain >>> Le dimanche 11 octobre 2015 21:30:43 UTC+3, Kristoffer Carlsson a écrit : >>>> >>>> Maybe you can give a link to the updated code? >>> >>>
