From mboxrd@z Thu Jan 1 00:00:00 1970 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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 EC835C433DF for ; Thu, 11 Jun 2020 01:41:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AE6352074B for ; Thu, 11 Jun 2020 01:41:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="up0JlHxU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE6352074B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5E6658D005A; Wed, 10 Jun 2020 21:41:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5962C8D004C; Wed, 10 Jun 2020 21:41:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4ABE38D005A; Wed, 10 Jun 2020 21:41:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0189.hostedemail.com [216.40.44.189]) by kanga.kvack.org (Postfix) with ESMTP id 387008D004C for ; Wed, 10 Jun 2020 21:41:34 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 03E751DF5 for ; Thu, 11 Jun 2020 01:41:34 +0000 (UTC) X-FDA: 76915228908.15.pet34_4d16d8526dcf Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin15.hostedemail.com (Postfix) with ESMTP id C7E901814A4C7 for ; Thu, 11 Jun 2020 01:41:33 +0000 (UTC) X-HE-Tag: pet34_4d16d8526dcf X-Filterd-Recvd-Size: 2475 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Thu, 11 Jun 2020 01:41:33 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5BB36207ED; Thu, 11 Jun 2020 01:41:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591839692; bh=aI4EjV5f9/HjHVAh29HMUiaOPXHAHW2GCXVbjdv9Byo=; h=Date:From:To:Subject:In-Reply-To:From; b=up0JlHxUITK+9/JJg4me/iHxe+/wg7vGFyUzz8tUSQtVNL3sMv+Jf5APKnzRpMM+3 Cy197+Ou5BFegYoOlpf81eH0qz7bqL3At7s4hkjUmGOmx02rDSM1gPoNbLbWzOp7h9 IIyG7aVcvlGvy5c7moGiHBliN91vy90t5JZKaaYI= Date: Wed, 10 Jun 2020 18:41:32 -0700 From: Andrew Morton To: akpm@linux-foundation.org, cyan@fb.com, hsiangkao@aol.com, joe@perches.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vvs@virtuozzo.com Subject: [patch 04/25] lib/lz4/lz4_decompress.c: document deliberate use of `&' Message-ID: <20200611014132.ApEMh2E59%akpm@linux-foundation.org> In-Reply-To: <20200610184053.3fa7368ab80e23bfd44de71f@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: C7E901814A4C7 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Joe Perches Subject: lib/lz4/lz4_decompress.c: document deliberate use of `&' This operation was intentional, but tools such as smatch will warn that it might not have been. Link: http://lkml.kernel.org/r/3bf931c6ea0cae3e23f3485801986859851b4f04.camel@perches.com Cc: Yann Collet Cc: Vasily Averin Cc: Gao Xiang Signed-off-by: Andrew Morton --- lib/lz4/lz4_decompress.c | 3 +++ 1 file changed, 3 insertions(+) --- a/lib/lz4/lz4_decompress.c~lib-lz4-lz4_decompressc-document-deliberate-use-of +++ a/lib/lz4/lz4_decompress.c @@ -141,6 +141,9 @@ static FORCE_INLINE int LZ4_decompress_g * space in the output for those 18 bytes earlier, upon * entering the shortcut (in other words, there is a * combined check for both stages). + * + * The & in the likely() below is intentionally not && so that + * some compilers can produce better parallelized runtime code */ if ((endOnInput ? length != RUN_MASK : length <= 8) /* _