25 Feb, 2017
1 commit
-
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
Acked-by: Yury Norov
Acked-by: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Apr, 2015
1 commit
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This file contains implementation for all find_*_bit{,_le}
So giving it more generic name looks reasonable.Signed-off-by: Yury Norov
Reviewed-by: Rasmus Villemoes
Reviewed-by: George Spelvin
Cc: Alexey Klimov
Cc: David S. Miller
Cc: Daniel Borkmann
Cc: Hannes Frederic Sowa
Cc: Lai Jiangshan
Cc: Mark Salter
Cc: AKASHI Takahiro
Cc: Thomas Graf
Cc: Valentin Rothberg
Cc: Chris Wilson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
