linux-kernel - [PATCH 2/3] kconfig: avoid multiple calls to strlen

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Date:	Sat, 13 Jul 2013 20:08:24 +0200
From:	"Yann E. MORIN" <yann.morin.1998@...e.fr>
To:	linux-kbuild@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, Michal Marek <mmarek@...e.cz>,
	Jean Delvare <jdelvare@...e.de>,
	"Yann E. MORIN" <yann.morin.1998@...e.fr>
Subject: [PATCH 2/3] kconfig: avoid multiple calls to strlen

From: "Yann E. MORIN" <yann.morin.1998@...e.fr>

Calls to strlen are costly, so avoid calling strln as much as we can.

Reported-by: Jean Delvare <jdelvare@...e.de>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@...e.fr>
Cc: Jean Delvare <jdelvare@...e.de>
---
 scripts/kconfig/symbol.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index d550300..020a0ac 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -967,7 +967,7 @@ static int sym_rel_comp( const void *sym1, const void *sym2 )
 {
 	struct sym_match *s1 = *(struct sym_match **)sym1;
 	struct sym_match *s2 = *(struct sym_match **)sym2;
-	int l1, l2;
+	int exact1, exact2;
 
 	/* Exact match:
 	 * - if matched length on symbol s1 is the length of that symbol,
@@ -978,11 +978,11 @@ static int sym_rel_comp( const void *sym1, const void *sym2 )
 	 * exactly; if this is the case, we can't decide which comes first,
 	 * and we fallback to sorting alphabetically.
 	 */
-	l1 = s1->eo - s1->so;
-	l2 = s2->eo - s2->so;
-	if (l1 == strlen(s1->sym->name) && l2 != strlen(s2->sym->name))
+	exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
+	exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
+	if (exact1 && !exact2)
 		return -1;
-	if (l1 != strlen(s1->sym->name) && l2 == strlen(s2->sym->name))
+	if (!exact1 && exact2)
 		return 1;
 
 	/* As a fallback, sort symbols alphabetically */
-- 
1.8.1.2

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