On 02/09/2013 09:56 AM, Johan Holmquist wrote: [--snip--]
It just so happened that the old code triggered some aggressive optimization unbeknownst to everyone, **including the original developer**, while the new code did not. (This optimization maybe even was triggered only on a certain version of the compiler, the one that happened to be in use at the time.)
I fear being P some day.
Maybe this is something that would never happen in practice, but how to be sure...
It's definitely a valid point, but isn't that an argument *for* testing for preformance regressions rather than *against* compiler optimizations? Actually, it'd be really nice if you could have statically verifiable big-O performance assertions in the code. I'm guessing that a lot of work will have been done in this area. Anyone have any pointers to such work? Regards,