[PATCH net-next] fib_trie: avoid a redundant bit judgement in inflate

From: baker . kernel
Date: Sun Sep 29 2013 - 09:25:43 EST


From: "baker.zhang" <baker.kernel@xxxxxxxxx>

Because 'node' is the i'st child of 'oldnode',
thus, here 'i' equals
tkey_extract_bits(node->key, oldtnode->pos, oldtnode->bits)

we just get 1 more bit,
and need not care the detail value of this bits.

Signed-off-by: baker.zhang <baker.kernel@xxxxxxxxx>
---
net/ipv4/fib_trie.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 3df6d3e..92a4c7f8 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -762,12 +762,9 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn)

if (IS_LEAF(node) || ((struct tnode *) node)->pos >
tn->pos + tn->bits - 1) {
- if (tkey_extract_bits(node->key,
- oldtnode->pos + oldtnode->bits,
- 1) == 0)
- put_child(tn, 2*i, node);
- else
- put_child(tn, 2*i+1, node);
+ put_child(t, tn,
+ tkey_extract_bits(node->key, oldtnode->pos, oldtnode->bits + 1),
+ node);
continue;
}

--
1.8.1.2

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