On Tue, Apr 04, 2023 at 09:35:29PM +0000, Paul via Digitalmars-d-learn wrote: [...] > Well Steven just making the change you said reduced the execution time > from ~6-7 secs to ~3 secs. Then, including the 'parallel' in the > foreach statement took it down to ~1 sec. > > Boy lesson learned in appending-to and zeroing dynamic arrays in a hot > loop!
Best practices for arrays in hot loops: - Avoid appending if possible; instead, pre-allocate outside the loop. - Where possible, reuse existing arrays instead of discarding old ones and allocating new ones. - Use slices where possible instead of making copies of subarrays (this esp. applies to strings). - Where possible, prefer sequential access over random access (take advantage of the CPU cache hierarchy). T -- Famous last words: I *think* this will work...
