On Monday, 16. February 2009 11:38:49 you wrote: > >> Well, I guess that's a job for the compiler/optimizer. I did a quick > >> test by writing two versions of a small program initializing a static > >> variable with zero and one version that doesn't (=zeroed in .bss). Guess > >> what, the size of the resulting executable stays the same. > >> > >> When I initialize the variable with a non-zero value, then the program > >> size increases. I tested "-O2", "-O0" and "-Os" and the results where > >> the same. Feel free to look at the assembler output, though I guess this > >> optimization is not measurable and makes the code harder to read :o) > > > > For gcc, this depends on the -fno-zero-initialized-in-bss option. > > Recommendations to avoid zero initialization generally come from > > a time when gcc didn't do this by default. Now it is more just > > personal preference. > > I think the 3.x versions don't do this by default, so as long as they're > supported by the kernel, we should expect people to use them and not > assume defaults of later versions. Thanks for clearing this up, Philip and Patrick. So we've got so far: 1. Better readbility by writing "xyz = NULL;" 2. Correct and a tiny bit larger code using gcc 3 3. Correct and compact code using gcc 4 (released April 2005). I guess the assembler code generated from gcc 3 <-> gcc 4 will have other performance/size differences, but it's Patrick's final decision what to do :-) Cheers, Thomas -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
