Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!mailrus!ncar!ico!vail!rcd From: rcd@ico.ISC.COM (Dick Dunn) Newsgroups: comp.software-eng Subject: Re: C source lines in file Summary: not uncommon...but still wrong! Keywords: C Message-ID: <16019@vail.ICO.ISC.COM> Date: 17 Aug 89 22:39:35 GMT References: <35120@ccicpg.UUCP> <10707@smoke.BRL.MIL> <257@opel.UUCP> Organization: Interactive Systems Corp, Boulder, CO Lines: 27 johnk@opel.UUCP (John Kennedy) writes: > It is not uncommon to generate NCSL (Non-Commentary Source Lines) for > purposes of productivity. I assume this intended "productivity measurement". And sure, it's not uncommon...but it's still wrong. A count of non-commentary source lines says nothing about the amount of actual code produced, nor about productivity. In fact, it's worse than that: If you tell people their productivity will be judged (in part) on NCSL, their coding style will change--probably for the worse. An experienced eye can often tell whether code was written with an eye to NCSL as a productivity measure! > ...NCSL estimates have a relationship to > size and execution time predictions... They have some relationship to code size--not very good, but possibly slightly useful if you compensate for density of code (number of tokens per line). They have little or no relationship to execution time predic- tions; in too many cases the relationship will be inverted. Consider replacing an algorithm which is O(n^2) in time with a more complicated O(n*log(n)) algorithm. Or consider manual inline expansion of time-critical code sequences instead of using a procedure. Both increase the program text size in order to decrease execution time. -- Dick Dunn rcd@ico.isc.com uucp: {ncar,nbires}!ico!rcd (303)449-2870 ...Are you making this up as you go along?