From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-2.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,T_DKIM_INVALID, T_RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 521BE1F404 for ; Fri, 26 Jan 2018 20:55:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751530AbeAZUzK (ORCPT ); Fri, 26 Jan 2018 15:55:10 -0500 Received: from mail-pf0-f194.google.com ([209.85.192.194]:37254 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751178AbeAZUzJ (ORCPT ); Fri, 26 Jan 2018 15:55:09 -0500 Received: by mail-pf0-f194.google.com with SMTP id p1so1041127pfh.4 for ; Fri, 26 Jan 2018 12:55:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:references:date:in-reply-to:message-id :user-agent:mime-version; bh=kz0Y4BGp8Jp3R92iFWLOoAqRNCHOKiFywRN98MuoJ+g=; b=Bu4MLSWmMclBD90ntPWUvTtzvETzFOmy1i6cedmbKqMhS9RVq8/1UR9GXv8oJiKxGp mF3Wh7KNZPgWt8uJZRCkdngNWRFMxCsQGxOl4xYFvp64nNypGuDedqpSpFoPh2iKtZcK U0i01bVTOP+FHBpRa/RbedekZdh034wbtmnT7KV1tGwf5KBtozZiB3nXQ+W47/MPFyXE R83f+FwBElFCWi01zax6gkWofOwxWAZ0z9YIWeyFkHXTg6uXMDaVFeskI5OEK4HBokuZ sFjxhX4IaR+C671BtnWOt8ByeUBxLZ6UM+rnGyPLATKN/ql+fAv6U0mDyz/m1/3LhBcg 8cnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:references:date :in-reply-to:message-id:user-agent:mime-version; bh=kz0Y4BGp8Jp3R92iFWLOoAqRNCHOKiFywRN98MuoJ+g=; b=C/uR+0wTqOu2sg37jdVBTEAb2wFGpIVcUY2UlryeRui4zj1QDw38oGInErUenmt9bd JwHLGxtpzELcetL/YmJ/mq7x6EeR5kGNuAgmZGBgDsX1cAgN8Hh1w4NNyyrlLaogXg8I hRQHPqAtV/XqNCGdnVXwSYUktKxhFg9I9/gxI6NhAZ1LiSSfd269If2hOodGbEzNxoLS 0VuJM71WmwwacEtmtzMarfDKcneJ88xlq13SdP4ywqGDBOuAo7wdebcPDB4JlQkce+s4 sipVVo8kh6X26njC5CJG8nYpQ4C1jLmVvWafwKh+MDiVuksjZskMCokrYfFBygRW2Z0r yXAA== X-Gm-Message-State: AKwxytekKgx8XQtAtK1bLG4cLsxoq2TgsROZ8XPDXSkYoVxVrsJ8/Ixu hlndcGTiGacFE9deQEQialY= X-Google-Smtp-Source: AH8x227swBp74aEcAmkb5cZjE3MEvxtUNOoSPBTeeZOHP/9rJXfWsqOz24PukMHtK1usYsjsfIasmA== X-Received: by 2002:a17:902:2be4:: with SMTP id l91-v6mr15128116plb.387.1517000108648; Fri, 26 Jan 2018 12:55:08 -0800 (PST) Received: from localhost ([2620:0:1000:8622:3d49:4bb2:1738:a537]) by smtp.gmail.com with ESMTPSA id b8sm18686205pff.31.2018.01.26.12.55.07 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Fri, 26 Jan 2018 12:55:07 -0800 (PST) From: Junio C Hamano To: Derrick Stolee Cc: git@vger.kernel.org, peff@peff.net, git@jeffhostetler.com, sbeller@google.com, dstolee@microsoft.com Subject: Re: [PATCH 05/14] packed-graph: implement construct_graph() References: <20180125140231.65604-1-dstolee@microsoft.com> <20180125140231.65604-6-dstolee@microsoft.com> Date: Fri, 26 Jan 2018 12:55:06 -0800 In-Reply-To: <20180125140231.65604-6-dstolee@microsoft.com> (Derrick Stolee's message of "Thu, 25 Jan 2018 09:02:22 -0500") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Derrick Stolee writes: > + packedDate[0] = htonl((*list)->date >> 32); > + packedDate[1] = htonl((*list)->date); How forward-looking do we want to be? The commit.date field happens to be unsigned so there is no point masking the result of right shifting it, but that would not stay to be the case once we start supporting negative timestamps, for example. Also, I recall that you plan to squeeze generation number in 30 bits or so of one of these words. Wouldn't it mean that higher order bits of commit.date must be masked out anyway, even though we do not have to worry about right shift propagating the sign-bit down? Also, would >>32 be a problem if commit.date is an uint32 (and shifting all its bits out to the right)?