Hi, On Wed, Sep 04, 2019 at 10:21:28AM +0200, Florian Westphal wrote: > Phil Sutter <phil@xxxxxx> wrote: > > What we need in b is 'ff ff ff 00' for a prefix length of 24. Your > > suggested alternative does not compile, so I tried both options for the > > closing brace: > > > > | htonl((1 << 24) - 1) > > > > This turns into '00 ff ff ff' for both LE and BE, the opposite of what > > we need. > > > > | htonl((1 << 24)) - 1 > > > > This turns into '00 00 00 00' on LE and '00 ff ff ff' on BE. > > > > My code leads to correct result on either architecture and I don't see a > > simpler way of doing it. > > htonl(~0u << (32 - i)) would work, assuming i > 0 and <= 32. Ah, indeed! Left-shifting all-ones didn't come to mind. I'll send a v2. Thanks, Phil
