[PATCH] lib/idr.c: remove duplicate bound checking in sub_alloc

From: Liu Sha
Date: Thu Mar 19 2015 - 23:50:56 EST


The INT_MAX bound checking in sub_alloc checks two conditions to see
whether the signed integer "id" is beyond INT_MAX:

if ((id >= MAX_IDR_BIT) || (id < 0))
return -ENOSPC;

These two conditions are actually the same for "int" variable so one
of them can be removed. If the above snippet is compiled with -Os option
of gcc, only "id < 0" will remain in disassembly code.

Signed-off-by: Liu Sha <sz_liusha@xxxxxxxxxxxxxxx>
---
lib/idr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/idr.c b/lib/idr.c
index 5335c43..df545ad 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -262,7 +262,7 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa,
sh = IDR_BITS*l;
id = ((id >> sh) ^ n ^ m) << sh;
}
- if ((id >= MAX_IDR_BIT) || (id < 0))
+ if (id >= MAX_IDR_BIT)
return -ENOSPC;
if (l == 0)
break;
--
2.1.1

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