On 16/08/22 15:13, Yury Norov wrote: > On Tue, Aug 16, 2022 at 07:07:23PM +0100, Valentin Schneider wrote: >> @@ -59,7 +63,9 @@ unsigned long _find_next_bit(const unsigned long *addr1, >> >> tmp = addr1[start / BITS_PER_LONG]; >> if (addr2) >> - tmp &= addr2[start / BITS_PER_LONG]; >> + tmp &= negate ? >> + ~addr2[start / BITS_PER_LONG] : >> + addr2[start / BITS_PER_LONG]; >> tmp ^= invert; >> } > > So it flips addr2 bits twice - first with new 'negate', and second > with the existing 'invert'. There is no such combination in the > existing code, but the pattern looks ugly, particularly because we use > different inverting approaches. Because of that, and because XOR trick > generates better code, I'd suggest something like this: > > tmp = addr1[start / BITS_PER_LONG] ^ invert1; > if (addr2) > tmp &= addr2[start / BITS_PER_LONG] ^ invert2; That does look much better, and also gets rid of the ternary. Thanks!
