Commit 7516be99 authored by Yury Norov's avatar Yury Norov
Browse files

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: default avatarYury Norov <yury.norov@gmail.com>
Tested-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
parent bc9d6635

include/linux/find.h

+2 −2
Original line number Diff line number Diff line
@@ -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))