On Sun, Jan 23, 2011 at 10:46 PM, Johan Corveleyn <jcor...@gmail.com> wrote: > On Sat, Jan 8, 2011 at 6:50 AM, Stefan Fuhrmann > <stefanfuhrm...@alice-dsl.de> wrote: >> On 03.01.2011 02:14, Johan Corveleyn wrote: >>> It would be interesting to see where the biggest gains >>> are coming from (I'm guessing from the "per-machine-word" >>> reading/comparing; I'd like to try that first, maybe together with the >>> allocating of the file[] on the stack; I'd like to avoid >>> special-casing file_len==2, splitting up functions in *_slow and >>> *_fast, because it makes it a lot more difficult imho (so I'd only >>> like to do that if it's a significant contributor)). But if you want >>> to leave that as an exercise for the reader, that's fine as well :-). >> >> Exercise is certainly not a bad thing ;) >> >> But I think, the stack variable is certainly helpful >> and easy to do. While "chunky" operation gives >> a *big* boost, it is much more difficult to code if >> you need to compare multiple sources. It should >> be possible, though. > > Ok, I finished the exercise :-). > > - File info structures on stack instead of on heap: committed in > r1060625. Gives 10% boost. > > - chunky operation for multiple sources: committed in r1062532. Gives > ~250% boost on my machine.
Oops, as some people pointed out on IRC, that should be ~60% (I meant 2.5 times faster, going from ~50s to ~20s, so that's about ~60% less time spent in datasources_open). -- Johan
