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@gmail.com>

diff --git a/include/linux/find.h b/include/linux/find.h
index 3b746a183216dc94e94c8ad25e1ff510ce5cef5a..0cdfab9734a61638941363d94bf19f05b11142ea 100644 (file)
--- 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