Optimized max_part_bit in sql_select.cc to use my_find_first_bit.

montywi · montywi · commit 886d740ad770 · 2024-09-07T16:51:52.000+03:00
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
@@ -6967,12 +6967,13 @@ Item_equal::add_key_fields(JOIN *join, KEY_FIELD **key_fields,
 }
 
 
-static uint
+static inline uint
 max_part_bit(key_part_map bits)
 {
-  uint found;
-  for (found=0; bits & 1 ; found++,bits>>=1) ;
-  return found;
+  if (bits == 0)
+    return 0;
+  /* find first zero bit by reverting all bits and find first bit */
+  return my_find_first_bit(~(ulonglong) bits);
 }
 
 

Original file line number	Diff line number	Diff line change
`@@ -6967,12 +6967,13 @@ Item_equal::add_key_fields(JOIN join, KEY_FIELD *key_fields,`
`6967`	`6967`	`}`
`6968`	`6968`
`6969`	`6969`
`6970`		`-static uint`
	`6970`	`+static inline uint`
`6971`	`6971`	`max_part_bit(key_part_map bits)`
`6972`	`6972`	`{`
`6973`		`- uint found;`
`6974`		`- for (found=0; bits & 1 ; found++,bits>>=1) ;`
`6975`		`- return found;`
	`6973`	`+ if (bits == 0)`
	`6974`	`+ return 0;`
	`6975`	`+ /* find first zero bit by reverting all bits and find first bit */`
	`6976`	`+ return my_find_first_bit(~(ulonglong) bits);`
`6976`	`6977`	`}`
`6977`	`6978`
`6978`	`6979`