From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 422775A71 for ; Thu, 23 Apr 2015 10:11:44 +0200 (CEST) Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP; 23 Apr 2015 01:11:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,629,1422950400"; d="scan'208";a="560535606" Received: from unknown ([10.237.220.106]) by orsmga003.jf.intel.com with SMTP; 23 Apr 2015 01:11:41 -0700 Received: by (sSMTP sendmail emulation); Thu, 23 Apr 2015 09:11:39 +0025 Date: Thu, 23 Apr 2015 09:11:39 +0100 From: Bruce Richardson To: Pawel Wodkowski Message-ID: <20150423081138.GA8592@bricha3-MOBL3> References: <1429716828-19012-1-git-send-email-rkerur@gmail.com> <1429716828-19012-2-git-send-email-rkerur@gmail.com> <55389E44.8030603@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55389E44.8030603@intel.com> Organization: Intel Shannon Ltd. User-Agent: Mutt/1.5.23 (2014-03-12) Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH] Implement memcmp using AVX/SSE instructio X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Apr 2015 08:11:44 -0000 On Thu, Apr 23, 2015 at 09:24:52AM +0200, Pawel Wodkowski wrote: > On 2015-04-22 17:33, Ravi Kerur wrote: > >+/** > >+ * Compare bytes between two locations. The locations must not overlap. > >+ * > >+ * @note This is implemented as a macro, so it's address should not be taken > >+ * and care is needed as parameter expressions may be evaluated multiple times. > >+ * > >+ * @param src_1 > >+ * Pointer to the first source of the data. > >+ * @param src_2 > >+ * Pointer to the second source of the data. > >+ * @param n > >+ * Number of bytes to compare. > >+ * @return > >+ * true if equal otherwise false. > >+ */ > >+static inline bool > >+rte_memcmp(const void *src_1, const void *src, > >+ size_t n) __attribute__((always_inline)); > You are exposing this as public API, so I think you should follow > description bellow or not call this _memcmp_ > > int memcmp(const void *s1, const void *s2, size_t n); > > The memcmp() function returns an integer less than, equal to, or greater > than > zero if the first n bytes of s1 is found, respectively, to be > less than, to > match, or be greater than the first n bytes of s2. > +1 to this point. Also, if I read your quoted performance numbers in your earlier mail correctly, we are only looking at a 1-4% performance increase. Is the additional code to maintain worth the benefit? /Bruce > -- > Pawel