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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 643C7C433E0 for ; Thu, 18 Feb 2021 22:52:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2266064DFD for ; Thu, 18 Feb 2021 22:52:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229979AbhBRWwg (ORCPT ); Thu, 18 Feb 2021 17:52:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229945AbhBRWw0 (ORCPT ); Thu, 18 Feb 2021 17:52:26 -0500 Received: from mail-ej1-x636.google.com (mail-ej1-x636.google.com [IPv6:2a00:1450:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CD4FC06178A for ; Thu, 18 Feb 2021 14:51:46 -0800 (PST) Received: by mail-ej1-x636.google.com with SMTP id d8so8412168ejc.4 for ; Thu, 18 Feb 2021 14:51:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rasmusvillemoes.dk; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=Vrc627xbuX2TMgkXGGkkQoTFvSmbGef3PT5dPjYaHq4=; b=G+VppJXi/ZOG8gHCQ6TFEVZSG0VMgwjTbKRWl1GBBX3e9vwfVqsXJnB+Swrbm9Mbki HeZGAKA758jQl1Wchle/AFqcf2AjQAMFFj13bi28/2IH0R2ELAAHaO0ZWoqacamBBtzs uUGJ8VNz+ZknAy1z21qDfTSQ4nYI2gdZIrkck= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Vrc627xbuX2TMgkXGGkkQoTFvSmbGef3PT5dPjYaHq4=; b=HkKnBerrJcvUOQxZSqta3PmzUzpvjn081qxcJQTLO+QsslUNFYmKzk43LLATEGqcAt Nj5Gvlz77UxAoGPNE/gZVAdkk/qJm+KHRU9jO1fIQy3+lvhr9ufYcsKHs9B5pBdIZpgr A3jHEkEMD3rWpVZ38E9fjzzqiPw8H9CrLk6E14BaI8pKdpfuS0lquH6h3atefCD4XpT1 CMOOl+qrOiVygeZttaSIsdgMtWPL4FFciLYFG2rUWJecPX4+sTJlVscxKAo3lqecXGaD x33C2Hw150IKXMJLLtND+HUnzXL2Vp45J/+lj4i25R8x8FPoopkVHpKbZ0cUx9q4YWvf rZ0Q== X-Gm-Message-State: AOAM531HDdclMw3CTc/dSj3jz4XT9RaU41ZwPK3cl8l7VfI0u4QTXmcD +VRGnfl5ncFCpLJUWYrmlToKkQ== X-Google-Smtp-Source: ABdhPJyKhm7W7GiwYBIDb8MWNmpDRdcqaFasH1pPiX6+4A01bLs1vLg+znuOAZacAYcYbAiyu87wIA== X-Received: by 2002:a17:906:301b:: with SMTP id 27mr2584079ejz.230.1613688705192; Thu, 18 Feb 2021 14:51:45 -0800 (PST) Received: from [192.168.1.149] ([80.208.71.141]) by smtp.gmail.com with ESMTPSA id m7sm3279119ejk.52.2021.02.18.14.51.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 18 Feb 2021 14:51:44 -0800 (PST) Subject: Re: [PATCH 04/14] lib: introduce BITS_{FIRST,LAST} macro To: Yury Norov , linux-kernel@vger.kernel.org Cc: linux-m68k@lists.linux-m68k.org, linux-arch@vger.kernel.org, linux-sh@vger.kernel.org, Alexey Klimov , Andrew Morton , Andy Shevchenko , Arnd Bergmann , David Sterba , Dennis Zhou , Geert Uytterhoeven , Jianpeng Ma , Joe Perches , John Paul Adrian Glaubitz , Josh Poimboeuf , Rich Felker , Stefano Brivio , Wei Yang , Wolfram Sang , Yoshinori Sato References: <20210218040512.709186-1-yury.norov@gmail.com> <20210218040512.709186-5-yury.norov@gmail.com> From: Rasmus Villemoes Message-ID: Date: Thu, 18 Feb 2021 23:51:43 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210218040512.709186-5-yury.norov@gmail.com> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/02/2021 05.05, Yury Norov wrote: > BITMAP_{LAST,FIRST}_WORD_MASK() in linux/bitmap.h duplicates the > functionality of GENMASK(). The scope of there macros is wider > than just bitmap. This patch defines 4 new macros: BITS_FIRST(), > BITS_LAST(), BITS_FIRST_MASK() and BITS_LAST_MASK() in linux/bits.h > on top of GENMASK() and replaces BITMAP_{LAST,FIRST}_WORD_MASK() > to avoid duplication and increase the scope of the macros. > Please include some info on changes in generated code, if any. When the parameter to the macro is a constant I'm sure it all folds to a compile-time constant either way, but when it's not, I'm not sure gcc can do the same optimizations when the expressions become more complicated. Rasmus