From: Yury Norov Date: Sat, 14 Aug 2021 21:17:07 +0000 (-0700) Subject: find: micro-optimize for_each_{set,clear}_bit() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7516be9931b8bc8bcaac8531f490b42ab11ded1e;p=linux.git find: micro-optimize for_each_{set,clear}_bit() The macros iterate thru all set/clear bits in a bitmap. They search a first bit using find_first_bit(), and the rest bits using find_next_bit(). Since find_next_bit() is called shortly after find_first_bit(), we can save few lines of I-cache by not using find_first_bit(). Signed-off-by: Yury Norov Tested-by: Wolfram Sang --- diff --git a/include/linux/find.h b/include/linux/find.h index 4500e8ab93e24..ae9ed52b52b8b 100644 --- a/include/linux/find.h +++ b/include/linux/find.h @@ -280,7 +280,7 @@ unsigned long find_next_bit_le(const void *addr, unsigned #endif #define for_each_set_bit(bit, addr, size) \ - for ((bit) = find_first_bit((addr), (size)); \ + for ((bit) = find_next_bit((addr), (size), 0); \ (bit) < (size); \ (bit) = find_next_bit((addr), (size), (bit) + 1)) @@ -291,7 +291,7 @@ unsigned long find_next_bit_le(const void *addr, unsigned (bit) = find_next_bit((addr), (size), (bit) + 1)) #define for_each_clear_bit(bit, addr, size) \ - for ((bit) = find_first_zero_bit((addr), (size)); \ + for ((bit) = find_next_zero_bit((addr), (size), 0); \ (bit) < (size); \ (bit) = find_next_zero_bit((addr), (size), (bit) + 1))