Ben Pfaff <blp <at> cs.stanford.edu> writes: > > Any objections against this patch? I ask because it intentionally > > violates the C99 constraint of not reading beyond the end of an array. > > However, the excess read can only occur on the final longword of an array, > > and only with an aligned longword read, so on all hardware I know of, the > > read won't fault even though it reads more bytes than strictly necessary; > > people accessing volatile I/O memory with side effects on read should not > > be using strchrnul in the first place. This code gives a much faster > > search than the original byte-wise approach. > > This approach will cause false-positive warnings under memory > debuggers such as Valgrind. However, anyone who notices such a > warning should be able to spot from the comments in the function > that it is still correct code given the assumption you have > above, so I don't think that is a big deal.
Given that, and the fact that the (less-efficient) glibc implementation also reads beyond bounds: http://sourceware.org/cgi-bin/cvsweb.cgi/libc/string/strchrnul.c? rev=1.1&content-type=text/x-cvsweb-markup&cvsroot=glibc So I've gone ahead and committed this. -- Eric Blake
