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Message-Id: <20220919210559.1509179-7-yury.norov@gmail.com> Date: Mon, 19 Sep 2022 14:05:58 -0700 From: Yury Norov <yury.norov@...il.com> To: linux-kernel@...r.kernel.org, netdev@...r.kernel.org, Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, "David S . Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Rasmus Villemoes <linux@...musvillemoes.dk>, Yury Norov <yury.norov@...il.com> Subject: [PATCH 6/7] lib/find: optimize for_each() macros Moving an iterator of the macros inside conditional part of for-loop helps to generate a better code. It had been first implemented in commit 7baac8b91f9871ba ("cpumask: make for_each_cpu_mask a bit smaller"). Now that cpumask for-loops are the aliases to bitmap loops, it's worth to optimize them the same way. Bloat-o-meter says: add/remove: 8/12 grow/shrink: 147/592 up/down: 4876/-24416 (-19540) Signed-off-by: Yury Norov <yury.norov@...il.com> --- include/linux/find.h | 56 ++++++++++++++++++++------------------------ 1 file changed, 25 insertions(+), 31 deletions(-) diff --git a/include/linux/find.h b/include/linux/find.h index 3b746a183216..0cdfab9734a6 100644 --- a/include/linux/find.h +++ b/include/linux/find.h @@ -458,31 +458,25 @@ unsigned long find_next_bit_le(const void *addr, unsigned #endif #define for_each_set_bit(bit, addr, size) \ - for ((bit) = find_next_bit((addr), (size), 0); \ - (bit) < (size); \ - (bit) = find_next_bit((addr), (size), (bit) + 1)) + for ((bit) = 0; (bit) = find_next_bit((addr), (size), (bit)), (bit) < (size); (bit)++) #define for_each_and_bit(bit, addr1, addr2, size) \ - for ((bit) = find_next_and_bit((addr1), (addr2), (size), 0); \ - (bit) < (size); \ - (bit) = find_next_and_bit((addr1), (addr2), (size), (bit) + 1)) + for ((bit) = 0; \ + (bit) = find_next_and_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\ + (bit)++) /* same as for_each_set_bit() but use bit as value to start with */ #define for_each_set_bit_from(bit, addr, size) \ - for ((bit) = find_next_bit((addr), (size), (bit)); \ - (bit) < (size); \ - (bit) = find_next_bit((addr), (size), (bit) + 1)) + for (; (bit) = find_next_bit((addr), (size), (bit)), (bit) < (size); (bit)++) #define for_each_clear_bit(bit, addr, size) \ - for ((bit) = find_next_zero_bit((addr), (size), 0); \ - (bit) < (size); \ - (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) + for ((bit) = 0; \ + (bit) = find_next_zero_bit((addr), (size), (bit)), (bit) < (size); \ + (bit)++) /* same as for_each_clear_bit() but use bit as value to start with */ #define for_each_clear_bit_from(bit, addr, size) \ - for ((bit) = find_next_zero_bit((addr), (size), (bit)); \ - (bit) < (size); \ - (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) + for (; (bit) = find_next_zero_bit((addr), (size), (bit)), (bit) < (size); (bit)++) /** * for_each_set_bitrange - iterate over all set bit ranges [b; e) @@ -492,11 +486,11 @@ unsigned long find_next_bit_le(const void *addr, unsigned * @size: bitmap size in number of bits */ #define for_each_set_bitrange(b, e, addr, size) \ - for ((b) = find_next_bit((addr), (size), 0), \ - (e) = find_next_zero_bit((addr), (size), (b) + 1); \ + for ((b) = 0; \ + (b) = find_next_bit((addr), (size), b), \ + (e) = find_next_zero_bit((addr), (size), (b) + 1), \ (b) < (size); \ - (b) = find_next_bit((addr), (size), (e) + 1), \ - (e) = find_next_zero_bit((addr), (size), (b) + 1)) + (b) = (e) + 1) /** * for_each_set_bitrange_from - iterate over all set bit ranges [b; e) @@ -506,11 +500,11 @@ unsigned long find_next_bit_le(const void *addr, unsigned * @size: bitmap size in number of bits */ #define for_each_set_bitrange_from(b, e, addr, size) \ - for ((b) = find_next_bit((addr), (size), (b)), \ - (e) = find_next_zero_bit((addr), (size), (b) + 1); \ + for (; \ + (b) = find_next_bit((addr), (size), (b)), \ + (e) = find_next_zero_bit((addr), (size), (b) + 1), \ (b) < (size); \ - (b) = find_next_bit((addr), (size), (e) + 1), \ - (e) = find_next_zero_bit((addr), (size), (b) + 1)) + (b) = (e) + 1) /** * for_each_clear_bitrange - iterate over all unset bit ranges [b; e) @@ -520,11 +514,11 @@ unsigned long find_next_bit_le(const void *addr, unsigned * @size: bitmap size in number of bits */ #define for_each_clear_bitrange(b, e, addr, size) \ - for ((b) = find_next_zero_bit((addr), (size), 0), \ - (e) = find_next_bit((addr), (size), (b) + 1); \ + for ((b) = 0; \ + (b) = find_next_zero_bit((addr), (size), (b)), \ + (e) = find_next_bit((addr), (size), (b) + 1), \ (b) < (size); \ - (b) = find_next_zero_bit((addr), (size), (e) + 1), \ - (e) = find_next_bit((addr), (size), (b) + 1)) + (b) = (e) + 1) /** * for_each_clear_bitrange_from - iterate over all unset bit ranges [b; e) @@ -534,11 +528,11 @@ unsigned long find_next_bit_le(const void *addr, unsigned * @size: bitmap size in number of bits */ #define for_each_clear_bitrange_from(b, e, addr, size) \ - for ((b) = find_next_zero_bit((addr), (size), (b)), \ - (e) = find_next_bit((addr), (size), (b) + 1); \ + for (; \ + (b) = find_next_zero_bit((addr), (size), (b)), \ + (e) = find_next_bit((addr), (size), (b) + 1), \ (b) < (size); \ - (b) = find_next_zero_bit((addr), (size), (e) + 1), \ - (e) = find_next_bit((addr), (size), (b) + 1)) + (b) = (e) + 1) /** * for_each_set_bit_wrap - iterate over all set bits starting from @start, and -- 2.34.1
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