rbtree: add __rb_change_child() helper function
Add __rb_change_child() as an inline helper function to replace code that
would otherwise be duplicated 4 times in the source.
No changes to binary size or speed.
Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/rbtree.c b/lib/rbtree.c
index 61cdd0e..de89a61 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -66,6 +66,19 @@
return (struct rb_node *)red->__rb_parent_color;
}
+static inline void
+__rb_change_child(struct rb_node *old, struct rb_node *new,
+ struct rb_node *parent, struct rb_root *root)
+{
+ if (parent) {
+ if (parent->rb_left == old)
+ parent->rb_left = new;
+ else
+ parent->rb_right = new;
+ } else
+ root->rb_node = new;
+}
+
/*
* Helper function for rotations:
* - old's parent and color get assigned to new
@@ -78,13 +91,7 @@
struct rb_node *parent = rb_parent(old);
new->__rb_parent_color = old->__rb_parent_color;
rb_set_parent_color(old, new, color);
- if (parent) {
- if (parent->rb_left == old)
- parent->rb_left = new;
- else
- parent->rb_right = new;
- } else
- root->rb_node = new;
+ __rb_change_child(old, new, parent, root);
}
void rb_insert_color(struct rb_node *node, struct rb_root *root)
@@ -375,13 +382,7 @@
while ((left = node->rb_left) != NULL)
node = left;
- if (rb_parent(old)) {
- if (rb_parent(old)->rb_left == old)
- rb_parent(old)->rb_left = node;
- else
- rb_parent(old)->rb_right = node;
- } else
- root->rb_node = node;
+ __rb_change_child(old, node, rb_parent(old), root);
child = node->rb_right;
parent = rb_parent(node);
@@ -410,13 +411,7 @@
if (child)
rb_set_parent(child, parent);
- if (parent) {
- if (parent->rb_left == node)
- parent->rb_left = child;
- else
- parent->rb_right = child;
- } else
- root->rb_node = child;
+ __rb_change_child(node, child, parent, root);
color:
if (color == RB_BLACK)
@@ -591,14 +586,7 @@
struct rb_node *parent = rb_parent(victim);
/* Set the surrounding nodes to point to the replacement */
- if (parent) {
- if (victim == parent->rb_left)
- parent->rb_left = new;
- else
- parent->rb_right = new;
- } else {
- root->rb_node = new;
- }
+ __rb_change_child(victim, new, parent, root);
if (victim->rb_left)
rb_set_parent(victim->rb_left, new);
if (victim->rb_right)