Re: [PATCH 2/3] kconfig: avoid multiple calls to strlen

From: Jean Delvare
Date: Tue Jul 16 2013 - 10:22:07 EST


Le Saturday 13 July 2013 Ã 20:08 +0200, Yann E. MORIN a Ãcrit :
> From: "Yann E. MORIN" <yann.morin.1998@xxxxxxx>
>
> Calls to strlen are costly, so avoid calling strln as much as we can.

Typo: strln -> strlen.

> Reported-by: Jean Delvare <jdelvare@xxxxxxx>
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@xxxxxxx>
> Cc: Jean Delvare <jdelvare@xxxxxxx>
> ---
> 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 */

Looks good and tested OK.

Reviewed-by: Jean Delvare <jdelvare@xxxxxxx>

--
Jean Delvare
Suse L3

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