From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.molgen.mpg.de (mx3.molgen.mpg.de [141.14.17.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D54003FC8 for ; Tue, 21 Sep 2021 10:11:26 +0000 (UTC) Received: from [192.168.178.35] (unknown [88.130.155.181]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) (Authenticated sender: pmenzel) by mx.molgen.mpg.de (Postfix) with ESMTPSA id 53A2761E64760; Tue, 21 Sep 2021 12:11:17 +0200 (CEST) Subject: Re: [PATCH v3] lib/zlib_inflate/inffast: Check config in C to avoid unused function warning To: Nathan Chancellor Cc: Nick Desaulniers , Christophe Leroy , Zhen Lei , Andrew Morton , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev References: <20210920084332.5752-1-pmenzel@molgen.mpg.de> From: Paul Menzel Message-ID: Date: Tue, 21 Sep 2021 12:11:16 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Dear Linux folks, Am 20.09.21 um 17:45 schrieb Nathan Chancellor: > On Mon, Sep 20, 2021 at 10:43:33AM +0200, Paul Menzel wrote: >> Building Linux for ppc64le with Ubuntu clang version 12.0.0-3ubuntu1~21.04.1 >> shows the warning below. >> >> arch/powerpc/boot/inffast.c:20:1: warning: unused function 'get_unaligned16' [-Wunused-function] >> get_unaligned16(const unsigned short *p) >> ^ >> 1 warning generated. >> >> Fix it, by moving the check from the preprocessor to C, so the compiler >> sees the use. >> >> Signed-off-by: Paul Menzel > > Reviewed-by: Nathan Chancellor > Tested-by: Nathan Chancellor > >> --- >> v2: Use IS_ENABLED >> v3: Use if statement over ternary operator as requested by Christophe >> >> lib/zlib_inflate/inffast.c | 13 ++++++------- >> 1 file changed, 6 insertions(+), 7 deletions(-) >> >> diff --git a/lib/zlib_inflate/inffast.c b/lib/zlib_inflate/inffast.c >> index f19c4fbe1be7..2843f9bb42ac 100644 >> --- a/lib/zlib_inflate/inffast.c >> +++ b/lib/zlib_inflate/inffast.c >> @@ -253,13 +253,12 @@ void inflate_fast(z_streamp strm, unsigned start) >> >> sfrom = (unsigned short *)(from); >> loops = len >> 1; >> - do >> -#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS >> - *sout++ = *sfrom++; >> -#else >> - *sout++ = get_unaligned16(sfrom++); >> -#endif >> - while (--loops); >> + do { >> + if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) >> + *sout++ = *sfrom++; >> + else >> + *sout++ = get_unaligned16(sfrom++); >> + } while (--loops); >> out = (unsigned char *)sout; >> from = (unsigned char *)sfrom; >> } else { /* dist == 1 or dist == 2 */ >> -- >> 2.33.0 Just for the record, I compared both object files by running `objdump -d`, and the result is the same. The binary differed (`vbindiff`), but I guess this is due to the increased revision (`make bindeb-pkg`). without a change (Linus’ current master): 0000 0B50: 00 00 00 00 00 00 00 00 1F 01 00 00 36 00 00 00 ........ ....6... ^ 0000 0B60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........ 0000 0B70: 00 00 00 00 00 00 00 00 29 01 00 00 32 00 00 00 ........ )...2... ^ v2 (ternary operator): 0000 0B50: 00 00 00 00 00 00 00 00 1C 01 00 00 36 00 00 00 ........ ....6... 0000 0B60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........ 0000 0B70: 00 00 00 00 00 00 00 00 26 01 00 00 32 00 00 00 ........ &...2... v3 (if-else statement): 0000 0B50: 00 00 00 00 00 00 00 00 1E 01 00 00 36 00 00 00 ........ ....6... 0000 0B60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........ 0000 0B70: 00 00 00 00 00 00 00 00 28 01 00 00 32 00 00 00 ........ (...2... Kind regards, Paul 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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 D9B43C433EF for ; Tue, 21 Sep 2021 10:11:59 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6BB9161038 for ; Tue, 21 Sep 2021 10:11:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6BB9161038 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=molgen.mpg.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4HDHK84pHdz2ynS for ; Tue, 21 Sep 2021 20:11:56 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=molgen.mpg.de (client-ip=141.14.17.11; helo=mx1.molgen.mpg.de; envelope-from=pmenzel@molgen.mpg.de; receiver=) Received: from mx1.molgen.mpg.de (mx3.molgen.mpg.de [141.14.17.11]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4HDHJc17Lkz2xtf for ; Tue, 21 Sep 2021 20:11:25 +1000 (AEST) Received: from [192.168.178.35] (unknown [88.130.155.181]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) (Authenticated sender: pmenzel) by mx.molgen.mpg.de (Postfix) with ESMTPSA id 53A2761E64760; Tue, 21 Sep 2021 12:11:17 +0200 (CEST) Subject: Re: [PATCH v3] lib/zlib_inflate/inffast: Check config in C to avoid unused function warning To: Nathan Chancellor References: <20210920084332.5752-1-pmenzel@molgen.mpg.de> From: Paul Menzel Message-ID: Date: Tue, 21 Sep 2021 12:11:16 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: llvm@lists.linux.dev, Zhen Lei , Nick Desaulniers , linux-kernel@vger.kernel.org, Paul Mackerras , Andrew Morton , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Dear Linux folks, Am 20.09.21 um 17:45 schrieb Nathan Chancellor: > On Mon, Sep 20, 2021 at 10:43:33AM +0200, Paul Menzel wrote: >> Building Linux for ppc64le with Ubuntu clang version 12.0.0-3ubuntu1~21.04.1 >> shows the warning below. >> >> arch/powerpc/boot/inffast.c:20:1: warning: unused function 'get_unaligned16' [-Wunused-function] >> get_unaligned16(const unsigned short *p) >> ^ >> 1 warning generated. >> >> Fix it, by moving the check from the preprocessor to C, so the compiler >> sees the use. >> >> Signed-off-by: Paul Menzel > > Reviewed-by: Nathan Chancellor > Tested-by: Nathan Chancellor > >> --- >> v2: Use IS_ENABLED >> v3: Use if statement over ternary operator as requested by Christophe >> >> lib/zlib_inflate/inffast.c | 13 ++++++------- >> 1 file changed, 6 insertions(+), 7 deletions(-) >> >> diff --git a/lib/zlib_inflate/inffast.c b/lib/zlib_inflate/inffast.c >> index f19c4fbe1be7..2843f9bb42ac 100644 >> --- a/lib/zlib_inflate/inffast.c >> +++ b/lib/zlib_inflate/inffast.c >> @@ -253,13 +253,12 @@ void inflate_fast(z_streamp strm, unsigned start) >> >> sfrom = (unsigned short *)(from); >> loops = len >> 1; >> - do >> -#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS >> - *sout++ = *sfrom++; >> -#else >> - *sout++ = get_unaligned16(sfrom++); >> -#endif >> - while (--loops); >> + do { >> + if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) >> + *sout++ = *sfrom++; >> + else >> + *sout++ = get_unaligned16(sfrom++); >> + } while (--loops); >> out = (unsigned char *)sout; >> from = (unsigned char *)sfrom; >> } else { /* dist == 1 or dist == 2 */ >> -- >> 2.33.0 Just for the record, I compared both object files by running `objdump -d`, and the result is the same. The binary differed (`vbindiff`), but I guess this is due to the increased revision (`make bindeb-pkg`). without a change (Linus’ current master): 0000 0B50: 00 00 00 00 00 00 00 00 1F 01 00 00 36 00 00 00 ........ ....6... ^ 0000 0B60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........ 0000 0B70: 00 00 00 00 00 00 00 00 29 01 00 00 32 00 00 00 ........ )...2... ^ v2 (ternary operator): 0000 0B50: 00 00 00 00 00 00 00 00 1C 01 00 00 36 00 00 00 ........ ....6... 0000 0B60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........ 0000 0B70: 00 00 00 00 00 00 00 00 26 01 00 00 32 00 00 00 ........ &...2... v3 (if-else statement): 0000 0B50: 00 00 00 00 00 00 00 00 1E 01 00 00 36 00 00 00 ........ ....6... 0000 0B60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........ 0000 0B70: 00 00 00 00 00 00 00 00 28 01 00 00 32 00 00 00 ........ (...2... Kind regards, Paul