From patchwork Mon Jan 18 10:55:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Ratiu X-Patchwork-Id: 12026973 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=-21.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_GIT 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 5E204C433E0 for ; Mon, 18 Jan 2021 10:58:08 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 0E53222242 for ; Mon, 18 Jan 2021 10:58:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E53222242 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JmcZIJkUxsM37Lx0qNo+d7+Pdy+2f0FZgkjqNFaa27A=; b=T2IDz7FEvMdRzQPWlRkJKt3MY T0hEiJU9DNNvxRDTEl1I4OglrnZhxwtPDIowby2jPgPhSSU2FsC1nH6mzVkD1bqajF1m4NfBg1H9u 7gZAH2HDUzJnj+/TjqYKoKU2M16xLuatXhQGlMHFr+wbUKsXmIBSpL809tntc9pZvSfzR8FrWmfRU WiSRk0aHJLWZeY7t5DcDBaFHvh3Mi9x3U0BZf97RTBbPIsPoxjJaS8jMOpjH/itrMcm1hk5nNYc9L OgruyJB14HUL33BAGq80If4SKR651jFLmNJJOpQGbPqiRfshA8z6NEUsaL0mOf462Y/InyHgIn2i0 tJL5XgwNQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l1SDF-0000eD-TH; Mon, 18 Jan 2021 10:56:46 +0000 Received: from bhuna.collabora.co.uk ([2a00:1098:0:82:1000:25:2eeb:e3e3]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l1SCw-0000XK-GN for linux-arm-kernel@lists.infradead.org; Mon, 18 Jan 2021 10:56:29 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: aratiu) with ESMTPSA id D3DFA1F44C3A From: Adrian Ratiu To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 RESEND 1/2] arm: lib: xor-neon: remove unnecessary GCC < 4.6 warning Date: Mon, 18 Jan 2021 12:55:56 +0200 Message-Id: <20210118105557.186614-2-adrian.ratiu@collabora.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210118105557.186614-1-adrian.ratiu@collabora.com> References: <20210118105557.186614-1-adrian.ratiu@collabora.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210118_055626_652746_9B443F45 X-CRM114-Status: GOOD ( 13.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Arnd Bergmann , Nick Desaulniers , Russell King , Linux Kernel Mailing List , clang-built-linux , Arvind Sankar , Nathan Chancellor , kernel@collabora.com, Ard Biesheuvel Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Nathan Chancellor Drop warning because kernel now requires GCC >= v4.9 after commit 6ec4476ac825 ("Raise gcc version requirement to 4.9") and clarify that -ftree-vectorize now always needs enabling for GCC by directly testing the presence of CONFIG_CC_IS_GCC. Another reason to remove the warning is that Clang exposes itself as GCC < 4.6 so it triggers the warning about GCC which doesn't make much sense and risks misleading users. As a side-note remark, -fttree-vectorize is on by default in Clang, but it currently does not work (see linked issues). Link: https://github.com/ClangBuiltLinux/linux/issues/496 Link: https://github.com/ClangBuiltLinux/linux/issues/503 Reported-by: Nick Desaulniers Reviewed-by: Nick Desaulniers Signed-off-by: Nathan Chancellor Signed-off-by: Adrian Ratiu --- arch/arm/lib/xor-neon.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/arch/arm/lib/xor-neon.c b/arch/arm/lib/xor-neon.c index b99dd8e1c93f..e1e76186ec23 100644 --- a/arch/arm/lib/xor-neon.c +++ b/arch/arm/lib/xor-neon.c @@ -19,15 +19,8 @@ MODULE_LICENSE("GPL"); * -ftree-vectorize) to attempt to exploit implicit parallelism and emit * NEON instructions. */ -#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) +#ifdef CONFIG_CC_IS_GCC #pragma GCC optimize "tree-vectorize" -#else -/* - * While older versions of GCC do not generate incorrect code, they fail to - * recognize the parallel nature of these functions, and emit plain ARM code, - * which is known to be slower than the optimized ARM code in asm-arm/xor.h. - */ -#warning This code requires at least version 4.6 of GCC #endif #pragma GCC diagnostic ignored "-Wunused-variable"