From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from purple.birch.relay.mailchannels.net (purple.birch.relay.mailchannels.net [23.83.209.150]) by sourceware.org (Postfix) with ESMTPS id 4ED13385415C for ; Mon, 31 Oct 2022 13:19:34 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 4ED13385415C Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=gotplt.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gotplt.org X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 1AE77822711; Mon, 31 Oct 2022 13:19:32 +0000 (UTC) Received: from pdx1-sub0-mail-a307 (unknown [127.0.0.6]) (Authenticated sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id 9A7C2822707; Mon, 31 Oct 2022 13:19:31 +0000 (UTC) ARC-Seal: i=1; s=arc-2022; d=mailchannels.net; t=1667222371; a=rsa-sha256; cv=none; b=alsIGoTFoNxLrcGpGkj4LGFM4yQzBKde5PcewJVprijrNUj7a65skiY/h/C750D8D7FGxc NJnUhDyWrCvBjdE7Sx+6jme6Jo8xjQKjCfJClWU7Pxg0vM5Uk4zaAEsqn2sRsYe7sUtrDL FOM3AINWi4laDh9D/6BoXGrmKwahRLZiJV9cOTd0QZ1qQDhwrMtOO/dOaLvqxEcOwQYBhT Pl7kvbcJpSi156wq73dwzIIbo/37bCLIQNa0xmONRD0+ON9iKT0nJwrlgg57W9rMXfx/iu QUnXEuPkcWckC0jH1oVfSNOaRRH+hUjjoJN+xM1xkvZqhUpDwp+y9MWb9EtEiw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=mailchannels.net; s=arc-2022; t=1667222371; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=2yDXNIoWOcndcNzcFYNMGOjnKx4MjTJt99TejNnTdIE=; b=ZJM/I23nbqi8pAlmbM3b1bkCYmbrao3n6ejMOwWKjIBOs2fPkYCcJJfcXgI8PxMjmKjuae 90B9AoIoS2yUJVdJfuRfdACvy3HwlS8gyZeN8fQ3aHVvT/DEHxs7dlcXQWo4DqwBxd0+Qu g2ZlP4frgqv8Zh7E2pFbOnRn+CEYSeHQYbkGDR7zMspe9IEhiPVKRJFMaBMUqSUYXjiSyX wvvtGI01zxWB98RmMEghYBXvWnmys72/BHcmsnOHqCqjaj8taa9rRKul5TNxXgrWRkCjiY j79MceK3/w9I0vblIyyEo9I1Qm5onWUTIEjTwXAgJhRAdCVcpa3x4bgO+EC2oQ== ARC-Authentication-Results: i=1; rspamd-7b8dfb6d4c-l5ttw; auth=pass smtp.auth=dreamhost smtp.mailfrom=siddhesh@gotplt.org X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org X-MC-Relay: Neutral X-MailChannels-SenderId: dreamhost|x-authsender|siddhesh@gotplt.org X-MailChannels-Auth-Id: dreamhost X-Irritate-Unite: 77f476a2725deb7b_1667222371902_2990035678 X-MC-Loop-Signature: 1667222371902:1433291419 X-MC-Ingress-Time: 1667222371902 Received: from pdx1-sub0-mail-a307 (pop.dreamhost.com [64.90.62.162]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384) by 100.119.144.184 (trex/6.7.1); Mon, 31 Oct 2022 13:19:31 +0000 Received: from [192.168.0.182] (bras-vprn-toroon4834w-lp130-05-174-93-41-34.dsl.bell.ca [174.93.41.34]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: siddhesh@gotplt.org) by pdx1-sub0-mail-a307 (Postfix) with ESMTPSA id 4N1DJf4nrDzTk; Mon, 31 Oct 2022 06:19:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gotplt.org; s=dreamhost; t=1667222371; bh=2yDXNIoWOcndcNzcFYNMGOjnKx4MjTJt99TejNnTdIE=; h=Date:Subject:To:From:Content-Type:Content-Transfer-Encoding; b=fQwFsXVgCICtneErHl9/JJEjZkE/fOLbd9a1j4nxsNyVR2wgrs/CzSl4LRWcyrB2f yTas8N3u0bK1vj3jEi2hT8JIffgCpxqi1XIRROBScoVkBGoRQP9dSD0REJq/CbTFdf ojfzRfpVR8c1LRjexPlGyAxPdGHSa2jybID2EAn/BKVrgj4Gv3ADo062YpCmjItgFf DzRKIFNIq89DggLXMBOyhbccAeKeFynZFUb/8g5tFk+SICRvew9X6jmkcyTvbUD4sw My1ywQLchqWuZm+4kTTerYRupSku9cja5/47RfFVVv+iWv2EAtNffgZFI1VX3FaoSO ye8/Mb2isM/EQ== Message-ID: <68b73e71-3806-91ba-ef48-69db951a45a8@gotplt.org> Date: Mon, 31 Oct 2022 09:19:29 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.0 Subject: Re: [PATCH v1 1/3] string: Add len=0 to {w}memcmp{eq} tests and benchtests To: Noah Goldstein , libc-alpha@sourceware.org References: <20221029201959.4082193-1-goldstein.w.n@gmail.com> Content-Language: en-US From: Siddhesh Poyarekar In-Reply-To: <20221029201959.4082193-1-goldstein.w.n@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-3036.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: LGTM. Reviewed-by: Siddhesh Poyarekar On 2022-10-29 16:19, Noah Goldstein via Libc-alpha wrote: > len=0 is valid and fairly common so should be tested. > --- > benchtests/bench-memcmp.c | 18 +++++++++--------- > string/test-memcmp.c | 16 ++++++++++------ > 2 files changed, 19 insertions(+), 15 deletions(-) > > diff --git a/benchtests/bench-memcmp.c b/benchtests/bench-memcmp.c > index d64eaa992e..b2816baebe 100644 > --- a/benchtests/bench-memcmp.c > +++ b/benchtests/bench-memcmp.c > @@ -63,7 +63,7 @@ IMPL (MEMCMP, 1) > > static void > do_one_test (json_ctx_t *json_ctx, impl_t *impl, const CHAR *s1, > - const CHAR *s2, size_t len, int exp_result) > + const CHAR *s2, size_t len) > { > size_t i, iters = INNER_LOOP_ITERS_LARGE; > timing_t start, stop, cur; > @@ -87,9 +87,6 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, > size_t i; > CHAR *s1, *s2; > > - if (len == 0) > - return; > - > align1 &= (4096 - CHARBYTES); > if (align1 + (len + 1) * CHARBYTES >= page_size) > return; > @@ -111,13 +108,16 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, > for (i = 0; i < len; i++) > s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % MAX_CHAR; > > - s1[len] = align1; > - s2[len] = align2; > - s2[len - 1] -= exp_result; > + if (len) > + { > + s1[len] = align1; > + s2[len] = align2; > + s2[len - 1] -= exp_result; > + } > > FOR_EACH_IMPL (impl, 0) > { > - do_one_test (json_ctx, impl, s1, s2, len, exp_result); > + do_one_test (json_ctx, impl, s1, s2, len); > } > > json_array_end (json_ctx); > @@ -147,7 +147,7 @@ test_main (void) > json_array_end (&json_ctx); > > json_array_begin (&json_ctx, "results"); > - for (i = 1; i < 32; ++i) > + for (i = 0; i < 32; ++i) > { > do_test (&json_ctx, i * CHARBYTES, i * CHARBYTES, i, 0); > do_test (&json_ctx, i * CHARBYTES, i * CHARBYTES, i, 1); > diff --git a/string/test-memcmp.c b/string/test-memcmp.c > index 181b689f68..18d8b0d9f1 100644 > --- a/string/test-memcmp.c > +++ b/string/test-memcmp.c > @@ -117,9 +117,6 @@ do_test (size_t align1, size_t align2, size_t len, int exp_result) > size_t i; > CHAR *s1, *s2; > > - if (len == 0) > - return; > - > align1 &= (4096 - CHARBYTES); > if (align1 + (len + 1) * CHARBYTES >= page_size) > return; > @@ -134,9 +131,16 @@ do_test (size_t align1, size_t align2, size_t len, int exp_result) > for (i = 0; i < len; i++) > s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % CHAR__MAX; > > - s1[len] = align1; > - s2[len] = align2; > - s2[len - 1] -= exp_result; > + if (len) > + { > + s1[len] = align1; > + s2[len] = align2; > + s2[len - 1] -= exp_result; > + } > + else > + { > + exp_result = 0; > + } > > FOR_EACH_IMPL (impl, 0) > do_one_test (impl, s1, s2, len, exp_result);