[PATCH] Use unsigned int types for a faster bsearch

[Eric Dumazet <dada1@cosmosbay.com>]

[-- Attachment #1: Type: text/plain, Size: 574 bytes --]

This patch avoids arithmetic on 'signed' types that are slower than 
'unsigned'. This saves space and cpu cycles.

size of kernel/sys.o before the patch (gcc-3.4.5)

    text    data     bss     dec     hex filename
   10924     252       4   11180    2bac kernel/sys.o

size of kernel/sys.o after the patch
    text    data     bss     dec     hex filename
   10903     252       4   11159    2b97 kernel/sys.o

I noticed that gcc-4.1.0 (from Fedora Core 5) even uses idiv instruction for 
(a+b)/2 if a and b are signed.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>


[-- Attachment #2: groups_search.patch --]
[-- Type: text/plain, Size: 540 bytes --]

--- a/kernel/sys.c	2006-03-20 18:42:41.000000000 +0100
+++ b/kernel/sys.c	2006-03-20 19:00:43.000000000 +0100
@@ -1375,7 +1375,7 @@
 /* a simple bsearch */
 int groups_search(struct group_info *group_info, gid_t grp)
 {
-	int left, right;
+	unsigned int left, right;
 
 	if (!group_info)
 		return 0;
@@ -1383,7 +1383,7 @@
 	left = 0;
 	right = group_info->ngroups;
 	while (left < right) {
-		int mid = (left+right)/2;
+		unsigned int mid = (left+right)/2;
 		int cmp = grp - GROUP_AT(group_info, mid);
 		if (cmp > 0)
 			left = mid + 1;