From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 27 Oct 2022 09:54:56 +0200 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1onxj5-003qIe-WF for lore@lore.pengutronix.de; Thu, 27 Oct 2022 09:54:56 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1onxj4-0002s8-V8 for lore@pengutronix.de; Thu, 27 Oct 2022 09:54:55 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+A8wH9iHFIUkC7/ocJNUu7IhITW83OuebRbWLOxIP5w=; b=pTvcsSecsIU9ZjePsyqaB69KKX jHOL4WThldI2Yvx8SqUub7bawptu1KzJWQbB+iGR96m1hFnvY7U3lBXiaM5fhSqWe74HZ21ZIeW+d KEB1epQmL4qUlUBVb8gnbs6tZGyXk03eHXyJPYfftuB1OdBohSeynz1peXMXU8frMxMG/6dKx+DJF 87b2bvoCN602Vn9cJ3e1vCcpX9rlmNXPlHWPiFaFvYdeVCUDKItvEt8PiCKaj9Nkk++ONbVyxkP8h FmZw/ddXvuyVHbuhswQX0d4A+S0zbqU6H5P797CrzbgXYiQRwrzlU5m2JURj5zaCoNvPIqVrEpCRt OvJaufBQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1onxhv-00CFUw-Ms; Thu, 27 Oct 2022 07:53:43 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1onxhn-00CFTO-UK for barebox@lists.infradead.org; Thu, 27 Oct 2022 07:53:39 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1onxhm-0002fH-GP; Thu, 27 Oct 2022 09:53:34 +0200 Message-ID: Date: Thu, 27 Oct 2022 09:53:34 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.12.0 Content-Language: en-US To: Sascha Hauer Cc: barebox@lists.infradead.org References: <20221026064205.2360041-1-a.fatoum@pengutronix.de> <20221026064205.2360041-3-a.fatoum@pengutronix.de> <20221027065651.GQ6702@pengutronix.de> <20221027073334.GS6702@pengutronix.de> From: Ahmad Fatoum In-Reply-To: <20221027073334.GS6702@pengutronix.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221027_005336_041608_3CE2FF8A X-CRM114-Status: GOOD ( 21.69 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-4.9 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 3/6] string: reduce strjoin runtime, drop trailing separator X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) On 27.10.22 09:33, Sascha Hauer wrote: > On Thu, Oct 27, 2022 at 09:24:20AM +0200, Ahmad Fatoum wrote: >> Hi, >> >> On 27.10.22 08:56, Sascha Hauer wrote: >>> On Wed, Oct 26, 2022 at 08:42:02AM +0200, Ahmad Fatoum wrote: >>>> The implementation of strjoin is a bit suboptimal. The destination >>>> string is traversed from the beginning due to strcat and we have a >>>> left-over separator at the end, while it should only be in-between. >>>> >>>> Fix this. >>> >>> Rather than fixing a just introduced function I would expect a patch >>> introducing strjoin() and then another one converting the time command >>> over to use it. >> >> What difference does it make? > > You wouldn't have to fixup code you just introduced. The alternative of changing stuff just to shift it around directly after doesn't sound that much more appealing, but I can do that anyway. > >>> >>> for (i = 0; i < arrlen; i++) { >>> p = stpcpy(p, arr[i]); >>> if (i < arrlen - 1) >>> p = stpcpy(p, separator); >>> } >>> >>> That would also allow you to optimize the allocated buffer size above. >> >> I like my version more. I dislike these once-only checks inside loops. > > No problem ;) > > for (i = 0; i < arrlen - 1; i++) { > p = stpcpy(p, arr[i]); > p = stpcpy(p, separator); > } > > stpcpy(p, arr[i]); I can do that, albeit with mempcpy. I already got separatorlen. Cheers, Ahmad > > Sascha > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |