From patchwork Fri Dec 11 09:08:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elijah Newren X-Patchwork-Id: 11967727 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F8F8C433FE for ; Fri, 11 Dec 2020 09:10:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B725A23F57 for ; Fri, 11 Dec 2020 09:10:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437380AbgLKJKU (ORCPT ); Fri, 11 Dec 2020 04:10:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437328AbgLKJJf (ORCPT ); Fri, 11 Dec 2020 04:09:35 -0500 Received: from mail-wm1-x342.google.com (mail-wm1-x342.google.com [IPv6:2a00:1450:4864:20::342]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65C9DC061793 for ; Fri, 11 Dec 2020 01:08:54 -0800 (PST) Received: by mail-wm1-x342.google.com with SMTP id x22so6894689wmc.5 for ; Fri, 11 Dec 2020 01:08:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=XL0RdMhJCBZ0gxMDc9iKNk8Af4u8BEydSMvvnNYLvbo=; b=cZLmAj6F/qCu9wdgsEXXr6BJ4S8o8Q6UZ0l6mNXEbNDXA7jOpvSj2kIiAttV4njvEY 71BK+4cg6djmt1Dj/DqOerHGFTU8Q+WnDZmL/rBBY1WXCSd6sp+nPwTgXNM+Y/aKyiqc 6S21Bj9/z8tJ7XDqtPHDgUNNlmfsadxIgMWdwqX20xymNzYUevx7LbuKiVoJmbQ+/SkB mUcyhJlSSty7M+Uy/9Ud/7i3CJ9xIx79Lo51++dmlO08Abz7ZQbhKzEzJVY+0s6+/uYt EOYwqM58UrzDVV0UNj1N3L8C6DrZPpyhWi/bAZckRUh1yv7L0u4w4MLcDsLN/P5kpPa5 g2tQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=XL0RdMhJCBZ0gxMDc9iKNk8Af4u8BEydSMvvnNYLvbo=; b=CuHVcV7RFhUwYaPNmTfSjZCwC8o6kP/3ADSHeQ/FRAiU5XpW44yyUsmQCEoXOvPySc +ePvu2PZb8JIrxPMhHHz0vHR1Tp7c5CnMm2Ud/8Se3DF3x9YU1LpwDXbyMBMBnxdEW/V N80SrVdAxj1BB3prmHrHGbCxfRTOWimYqgnW2+cxe9sO2KKRHkb2D/z2eT3qY15dPvrg cWFWFWLYb3gWyu7S30Q4TxqtgamHEFlC1VN6vsqsXlASponwHWoXh74eajq9sfyI3Ua8 vpPuApGy3sVoUrj5Ulav5rjj7ps7nsnbLYK57qxEtJPQN83kllv5kSMctz1+Y7VO04r+ LwaA== X-Gm-Message-State: AOAM531sGrSJIEGF870yx4UfpOmr4B4ecNvLY8jmLFx1O9dXh2cfcEXJ eaAqreg1f3LWSZGlkMfvE0icea/8L6I= X-Google-Smtp-Source: ABdhPJzQoodNMMhxa2/q9X18sdEfyQlcsiE4IzlwBPJ/xgakNmGQgvvTEPXvJyJiJqm6BDB7cVNtcA== X-Received: by 2002:a05:600c:d8:: with SMTP id u24mr12411954wmm.103.1607677732986; Fri, 11 Dec 2020 01:08:52 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id v64sm13235007wme.25.2020.12.11.01.08.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Dec 2020 01:08:52 -0800 (PST) Message-Id: <7214fa73fdd13418744903f6c769fdb77c9512ce.1607677728.git.gitgitgadget@gmail.com> In-Reply-To: References: Date: Fri, 11 Dec 2020 09:08:42 +0000 Subject: [PATCH v2 3/9] diffcore-rename: simplify limit check Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Elijah Newren , Taylor Blau , Elijah Newren , Elijah Newren Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Elijah Newren From: Elijah Newren diffcore-rename had two different checks of the form if ((a < limit || b < limit) && a * b <= limit * limit) This can be simplified to if (st_mult(a, b) <= st_mult(limit, limit)) which makes it clearer how we are checking for overflow, and makes it much easier to parse given the drop from 8 to 4 variable appearances. Signed-off-by: Elijah Newren --- diffcore-rename.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/diffcore-rename.c b/diffcore-rename.c index 1d6675c040d..16553ab259f 100644 --- a/diffcore-rename.c +++ b/diffcore-rename.c @@ -447,12 +447,16 @@ static int too_many_rename_candidates(int num_destinations, int num_sources, * growing larger than a "rename_limit" square matrix, ie: * * num_destinations * num_sources > rename_limit * rename_limit + * + * We use st_mult() to check overflow conditions; in the + * exceptional circumstance that size_t isn't large enough to hold + * the multiplication, the system won't be able to allocate enough + * memory for the matrix anyway. */ if (rename_limit <= 0) rename_limit = 32767; - if ((num_destinations <= rename_limit || num_sources <= rename_limit) && - ((uint64_t)num_destinations * (uint64_t)num_sources - <= (uint64_t)rename_limit * (uint64_t)rename_limit)) + if (st_mult(num_destinations, num_sources) + <= st_mult(rename_limit, rename_limit)) return 0; options->needed_rename_limit = @@ -468,9 +472,8 @@ static int too_many_rename_candidates(int num_destinations, int num_sources, continue; limited_sources++; } - if ((num_destinations <= rename_limit || limited_sources <= rename_limit) && - ((uint64_t)num_destinations * (uint64_t)limited_sources - <= (uint64_t)rename_limit * (uint64_t)rename_limit)) + if (st_mult(num_destinations, limited_sources) + <= st_mult(rename_limit, rename_limit)) return 2; return 1; }