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This saves 32 bytes on my x86-64 build, mostly due to alignment considerations and sharing more code between find_next_bit and find_next_zero_bit, but it does save a couple of instructions. There's really two parts to this commit: - First, the first half of the test: (!nbits || start >= nbits) is trivially a subset of the second half, since nbits and start are both unsigned - Second, while looking at the disassembly, I noticed that GCC was predicting the branch taken. Since this is a failure case, it's clearly the less likely of the two branches, so add an unlikely() to override GCC's heuristics. [mawilcox@microsoft.com: v2] Link: http://lkml.kernel.org/r/1483709016-1834-1-git-send-email-mawilcox@linuxonhyperv.com Link: http://lkml.kernel.org/r/1483709016-1834-1-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Yury Norov <ynorov@caviumnetworks.com> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>