From patchwork Wed Jan 14 14:17:49 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wilco Dijkstra X-Patchwork-Id: 4682 Received: (qmail 31457 invoked by alias); 14 Jan 2015 14:18:31 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 31289 invoked by uid 89); 14 Jan 2015 14:18:21 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL, BAYES_00, SPF_PASS autolearn=ham version=3.3.2 X-HELO: service87.mimecast.com From: "Wilco Dijkstra" To: Subject: [PATCH] Improve memccpy performance Date: Wed, 14 Jan 2015 14:17:49 -0000 Message-ID: <001f01d03004$e05abdb0$a1103910$@com> MIME-Version: 1.0 X-MC-Unique: 115011414175608301 Improve memccpy performance by using memchr/memcpy rather than a byte loop. Overall performance on bench-memccpy is > 2x faster when using the C implementation of memchr and an optimized memcpy. ChangeLog: 2015-01-14 Wilco Dijkstra wdijkstr@arm.com * string/memccpy.c (memccpy): Improve performance using memchr/memcpy. --- string/memccpy.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/string/memccpy.c b/string/memccpy.c index 70ee2ae..d4146f9 100644 --- a/string/memccpy.c +++ b/string/memccpy.c @@ -26,15 +26,15 @@ void * __memccpy (void *dest, const void *src, int c, size_t n) { - const char *s = src; - char *d = dest; - const char x = c; - size_t i = n; + void *p = memchr (src, c, n); - while (i-- > 0) - if ((*d++ = *s++) == x) - return d; + if (p != NULL) + { + n = p - src + 1; + return memcpy (dest, src, n) + n; + } + memcpy (dest, src, n); return NULL; }