From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-x22a.google.com (mail-oi1-x22a.google.com [IPv6:2607:f8b0:4864:20::22a]) by sourceware.org (Postfix) with ESMTPS id D9EAC385783F for ; Thu, 16 Feb 2023 18:38:11 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org D9EAC385783F Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=linaro.org Received: by mail-oi1-x22a.google.com with SMTP id u11so1598037oiw.9 for ; Thu, 16 Feb 2023 10:38:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:organization:from:references :to:content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=3VOZ1PcQVNyEc2cKLtdi2rRt7V5Q9leVqe6QOdBv1P0=; b=l8H8QOXxfzNgLjfpQG/l5hV3cjok4YZ4QwWf8VGnJWr8U051Yny60Vd+cB3TriK5uM FdrzAJroR4shtJyiJs4cGc9H/Y9T++NF8lsj4eiT5A4eO/ICHd5OVI4JYgtZ0Y5HVtpo wlvbvBNcN4XqPG9doywBXb2BjWlxwGQRFcRtlYuNOWciPGVdpG4qHwhT2ZntMTMJrMw/ EfuY5l4ZuXCcCT6AVhqxSFv4CmEOeE+/nr+3T1ZxyrnzfwMSk9LwLqqorrIJBlwUTr1V PrS1sQ0fm4cS0cFDMmgzMbmT4jju1ZpTEEM5zzl4tKLFGvkApCuFf7HTaEfyov6fPWJM IJhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:organization:from:references :to:content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=3VOZ1PcQVNyEc2cKLtdi2rRt7V5Q9leVqe6QOdBv1P0=; b=5GZAg+sJPBDPEfX6mTOqNa5C249dWZ0kdPK3OuUOxR+eYRySr9vFhSmRA0mEbEND+w aKwhwCc0EBV5hLuDS+M2AQGCTJVbv0w10kcn4U353YX/x3xeJdgdW3NHAr3Wk4HagPz3 UJYzgC7F2dcZxPlvIirtPGki1gTclU6uAmQayQXN5C+euSOcXx/dzJfd+dUrhtUjeAWS 5vsVit7CT7vRSxxNxlS6NM2oakJd+H26nQbH8djWispwFOuTStvVLWP2V0CqBzIl2vcS EP1tU/BDguof4XuCsG0iS/wAvwBN3i0/Ux12oIZh2Ys7rgW5bpO2iRZKAVeeNJcd7fsd nXog== X-Gm-Message-State: AO0yUKWS03kJPQKOwFF0JdDYFVLEw+4Le3Za0QakKJv6cWPaVTYm4RMW w+JyeibhS6XMDuvEmEhTIOyM1JMENCSL+M2PCjg= X-Google-Smtp-Source: AK7set8wvdh5MIS+100bkjzjiz53lXGRLYB/Lr5IIhXpZr0+zG3v+f0I1TpSWXUtSCTozRWdfE2bgQ== X-Received: by 2002:a05:6808:1c6:b0:378:1a8b:cb88 with SMTP id x6-20020a05680801c600b003781a8bcb88mr2505086oic.47.1676572691008; Thu, 16 Feb 2023 10:38:11 -0800 (PST) Received: from ?IPV6:2804:1b3:a7c3:3a5:d16:437b:3b74:d999? ([2804:1b3:a7c3:3a5:d16:437b:3b74:d999]) by smtp.gmail.com with ESMTPSA id bh32-20020a056808182000b0037d6dd95756sm837815oib.33.2023.02.16.10.38.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 16 Feb 2023 10:38:10 -0800 (PST) Message-ID: <1809ebdf-e032-c34f-f685-d6718d525c2c@linaro.org> Date: Thu, 16 Feb 2023 15:38:07 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.7.2 Subject: Re: [PATCH 2/7] stdlib: Simplify getenv Content-Language: en-US To: Wilco Dijkstra , "libc-alpha@sourceware.org" References: <20230213135558.3328727-1-adhemerval.zanella@linaro.org> <20230213135558.3328727-3-adhemerval.zanella@linaro.org> <7d887c0c-7ab0-4057-df39-e8d671bca1d0@linaro.org> From: Adhemerval Zanella Netto Organization: Linaro In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-4.5 required=5.0 tests=BAYES_00,BODY_8BITS,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,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: On 16/02/23 15:02, Wilco Dijkstra wrote: > Hi Adhemerval, > > +  size_t len = strlen (name);; > +  for (char **ep = __environ; *ep != NULL; ++ep) > +    { > +      if (single_char && (*ep)[0] == name[0] && (*ep)[1] == '=') > +       return *ep + 2; > +      else if (strncmp (name, *ep, len) == 0 && (*ep)[len] == '=') > +       return *ep + len + 1; > > This is about 10-20% slower than the previous patch both for single-char and > multi-char case... The approach I showed it is far simpler and 3-4 times faster > (within 10% of original performance). Do you mean something like: size_t len = strlen (name);; for (char **ep = __environ; *ep != NULL; ++ep) { if (((*ep)[0] == name[0] && (*ep)[1] == '=') || (strncmp (name, *ep, len) == 0 && (*ep)[len] == '=')) return *ep + len + 1; }