First of all, try to avoid list concatenation (@) whenever possible, since it’s O(N) instead of O(1) prepend. I’d start with a (relatively) easy to follow plan of how to compute the cartesian outer product of lists. Prepend each element of the first list to each sublist in the cartesian product of the remaining lists. … Read more
For debugging EF queries, the easiest thing is to cast the query to ObjectQuery and use ToTraceString: var query = myContext.MyTable .Where(r => r.Id == searchId) .Select(r => r); Console.WriteLine(((ObjectQuery)query).ToTraceString()); This will show the underlying SQL for the query, and you can run the queries manually to debug why they are slow. Here is the … Read more
I have done some testing to see what’s what. Method I have tested the speeds of four scenarios. Each test consisted of a For loop doing 100 000 cycles. The core of the test was using a with statement to “grab” a cell. For i = 1 To 100000 With Cells(i, 1) End With Next … Read more
Judging from the name of your function, performance can’t be that critical to even consider moving parameters to global variables just to save time/space required to pass them as parameters (IO operations like checking files are much-much slower than calling functions and passing values to them). Slices in Go are just small descriptors, something like … Read more
The x64 architecture doubles the number of general purpose registers available in the x86 architecture, so that compilers are able to keep more data in (very fast) CPU registers rather than in (relatively slow) RAM.
In modern CPUs, rep stosb‘s and rep movsb‘s microcoded implementation actually uses stores that are wider than 1B, so it can go much faster than one byte per clock. (Note this only applies to stos and movs, not repe cmpsb or repne scasb. They’re still slow, unfortunately, like at best 2 cycles per byte compared … Read more
In your second version, you use the type Box<&’a mut [T]>, which means there are two levels of indirection to reach a T, because both Box and & are pointers. What you want instead is a Box<[T]>. I think the only sane way to construct such a value is from a Vec<T>, using the into_boxed_slice … Read more
You need to give more memory to the Gradle JVM, not to the compile task/JVM. One way to do so is via the GRADLE_OPTS environment variable (GRADLE_OPTS=-Xmx512m).