From patchwork Thu Sep 16 18:40:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 12499979 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 08738C433F5 for ; Thu, 16 Sep 2021 18:42:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E02F961139 for ; Thu, 16 Sep 2021 18:42:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349064AbhIPSnd (ORCPT ); Thu, 16 Sep 2021 14:43:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:44620 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348817AbhIPSnX (ORCPT ); Thu, 16 Sep 2021 14:43:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AD0D1610A6; Thu, 16 Sep 2021 18:41:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631817722; bh=15KiedaiGI/tJV9mvZsdFRG22825ewuodD6e49rg4sA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u6AuZ4vt5agTnwo61Uf+l27zC/1GALkEey8pT+6Pcskx3Dul4m9cofeGrXR2mAIjG QLNFjN1+jYqVjeJzeanWEYxD/JQDPdktS+jfeuLvmmc+DqriyRgWjor4gChl+nlUJe Shnv+d8tIcVdW3/2GnAVr+ij7VVyy3q6iUcO1fTB6rXwRI9vdeJOu2X5etSNQvFIo0 Y4R0DlgVoQv6Qfz7qup1DjhQJWp3wrSfu4jCHczN/hc5VCzUjFIpVST8b44tBw+msa Kkgyy7vQH8mVLBto1FjmKKpi1z9G/CxPggD9xq2u/+0cOKvMLWkeC8Df3pmOYWDIEK 5wtiQXfTQp4DA== From: Nathan Chancellor To: Masahiro Yamada Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Nick Desaulniers , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, llvm@lists.linux.dev, Nathan Chancellor , kernel test robot , Borislav Petkov Subject: [PATCH v2 1/2] x86/build: Do not add -falign flags unconditionally for clang Date: Thu, 16 Sep 2021 11:40:16 -0700 Message-Id: <20210916184017.1881473-2-nathan@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210916184017.1881473-1-nathan@kernel.org> References: <20210916184017.1881473-1-nathan@kernel.org> MIME-Version: 1.0 X-Patchwork-Bot: notify Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org clang does not support -falign-jumps and only recently gained support for -falign-loops. When one of the configuration options that adds these flags is enabled, clang warns and all cc-{disable-warning,option} that follow fail because -Werror gets added to test for the presence of this warning: clang-14: warning: optimization flag '-falign-jumps=0' is not supported [-Wignored-optimization-argument] To resolve this, add a couple of cc-option calls when building with clang; gcc has supported these options since 3.2 so there is no point in testing for their support. -falign-functions was implemented in clang-7, -falign-loops was implemented in clang-14, and -falign-jumps has not been implemented yet. Link: https://lore.kernel.org/r/YSQE2f5teuvKLkON@Ryzen-9-3900X.localdomain/ Link: https://lore.kernel.org/r/20210824022640.2170859-2-nathan@kernel.org/ Reported-by: kernel test robot Reviewed-by: Nick Desaulniers Acked-by: Borislav Petkov Signed-off-by: Nathan Chancellor --- arch/x86/Makefile_32.cpu | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) base-commit: a9086b878b7fd65894eb8cb1fa395dd469970566 diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu index e7355f8b51c2..94834c4b5e5e 100644 --- a/arch/x86/Makefile_32.cpu +++ b/arch/x86/Makefile_32.cpu @@ -4,6 +4,12 @@ tune = $(call cc-option,-mtune=$(1),$(2)) +ifdef CONFIG_CC_IS_CLANG +align := -falign-functions=0 $(call cc-option,-falign-jumps=0) $(call cc-option,-falign-loops=0) +else +align := -falign-functions=0 -falign-jumps=0 -falign-loops=0 +endif + cflags-$(CONFIG_M486SX) += -march=i486 cflags-$(CONFIG_M486) += -march=i486 cflags-$(CONFIG_M586) += -march=i586 @@ -19,11 +25,11 @@ cflags-$(CONFIG_MK6) += -march=k6 # They make zero difference whatsosever to performance at this time. cflags-$(CONFIG_MK7) += -march=athlon cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8,-march=athlon) -cflags-$(CONFIG_MCRUSOE) += -march=i686 -falign-functions=0 -falign-jumps=0 -falign-loops=0 -cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) -falign-functions=0 -falign-jumps=0 -falign-loops=0 +cflags-$(CONFIG_MCRUSOE) += -march=i686 $(align) +cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) $(align) cflags-$(CONFIG_MWINCHIPC6) += $(call cc-option,-march=winchip-c6,-march=i586) cflags-$(CONFIG_MWINCHIP3D) += $(call cc-option,-march=winchip2,-march=i586) -cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) -falign-functions=0 -falign-jumps=0 -falign-loops=0 +cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) $(align) cflags-$(CONFIG_MVIAC3_2) += $(call cc-option,-march=c3-2,-march=i686) cflags-$(CONFIG_MVIAC7) += -march=i686 cflags-$(CONFIG_MCORE2) += -march=i686 $(call tune,core2)