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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 66CF2C4332F for ; Fri, 16 Dec 2022 18:50:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:Message-ID: Mime-Version:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=BxZIrsk4s5/Kt+EZ97DFTMe7K6b9nHT6kOhhbSGOCSo=; b=sIo iIxLPayg56kBprS5UsyCGAfLDcHHFn7RwBbzryuXjnBs2EF30G/CGyQR1GSeA8sls943f+te26Ac3 C1aAJtu6CdUN8Vl5crr+HXYxpR8lRfNCg9ihr1v0aOCAvBBCB+/efKaEHmhs74+yHKv01qVwtEBhy QdfQ7fD8X3+A/2ZZ78qglEAt+9ydzAKJj5v7DxtELgpWSMia0Sei9ECNfUfdRAjbdvPcgwraJETof xq3Lrk0Vq+EuQJSsiKjwb3OPx58SIyZzBBXDnPVEMcBWDMhl+4goIhpV+JIIIVrfUWlOIzEz0u77m FRWoaoYfExscdMspMAoiiE90CQG4rqw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p6Fmv-00HOaL-Fz; Fri, 16 Dec 2022 18:50:29 +0000 Received: from mail-pf1-x44a.google.com ([2607:f8b0:4864:20::44a]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p6Fmt-00HOZB-HD for linux-riscv@lists.infradead.org; Fri, 16 Dec 2022 18:50:28 +0000 Received: by mail-pf1-x44a.google.com with SMTP id p17-20020a056a0026d100b005769067d113so1990415pfw.3 for ; Fri, 16 Dec 2022 10:50:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=BjZwbpxLn3gByaRwvryxHTkFqJNY30wsjieUWfidJPs=; b=VWqUuN5rbvErYZowCg1/pmfZgfIIFDthapPPmMM20S7mNNliYmfwqee9p9fOJUaxZj ucLeFdbB9AC0M2uySkphj4QpW+A4ZTbTqv34xMMUGlGBIlSc+JYY2cxnhPJwxLyXSmzV 56U4Nhm5hCu8a1QuQUy0C2nY23Cuo+QqeKQGMaw4hiCqzVNn8Sm55eD8pJNyaBrtRr0d ZH9VH/fVODDAF/TPIBQS6TRnQzmCnYsWasklGnjkuuYMzELuTp2Ixl93+Qa1gXEsvlYf 8n+2pYpCRFmz4GkycOJanAVLVNh1oS+s5LhfUrS0fC/mZ3+pljNI1uCtTHq1vIr7H6Qm jzog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=BjZwbpxLn3gByaRwvryxHTkFqJNY30wsjieUWfidJPs=; b=LgY58XzozLGj1lp9c3eWWClq9mmvj/1e8Z3sRjr31cP10Ukol5yb/xM4ayGH5/MCa6 GrmZvrO1tRV3OBTec9s0IDBs+m/WGUIPlU2JP9j8jPaxUyiWdxu78Nc8c0BQH0je0jxC XeZT+N9B6CTX7voa5FoznDd9bTs6Iwi6b1qBiI2oHIaJLiHzR0hIOdhtTVBosmu/yrDe PQwj0VDaFn9EmMwdi8n6btiN6Rn53bYDZpgK57IYb3hHhW1NZ9Jz8dIyYMmarGWA1Pm0 545SzWxqAVqd7vBNSW0HDDgTr7VhmmSR8cN1kk3EyEt7uJmXy6Bl17y6mSiiTirqGsqI 9Umw== X-Gm-Message-State: AFqh2ko4efHyxPm74L2WnexFF+1y+bFMvRYMhVpEu3YXJpKPRdPZZtlV eKMy+iUS6f59Q12ITzMZ8py1Sobf0hEGPQ== X-Google-Smtp-Source: AMrXdXtbTY4wcZoIq66QjNNVaFSRGJXlhFBTm/CgZNQ6XIoYuHltWbT2VVPUyzr6dSnWuzA3EKE98ARxdrpjIw== X-Received: from abdulras-llvm.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:219b]) (user=abdulras job=sendgmr) by 2002:a17:90a:9501:b0:219:1d0a:34a6 with SMTP id t1-20020a17090a950100b002191d0a34a6mr22237pjo.1.1671216624664; Fri, 16 Dec 2022 10:50:24 -0800 (PST) Date: Fri, 16 Dec 2022 18:50:12 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog Message-ID: <20221216185012.2342675-1-abdulras@google.com> Subject: [PATCH] riscv: avoid enabling vectorized code generation From: Saleem Abdulrasool To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Saleem Abdulrasool X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221216_105027_585592_A4E63BDD X-CRM114-Status: UNSURE ( 8.76 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org The compiler is free to generate vectorized operations for zero'ing memory. The kernel does not use the vector unit on RISCV, similar to architectures such as x86 where we use `-mno-mmx` et al to prevent the implicit vectorization. Perform a similar check for `-mno-implicit-float` to avoid this on RISC-V targets. Signed-off-by: Saleem Abdulrasool --- arch/riscv/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 0d13b597cb55..68433476a96e 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -89,6 +89,10 @@ KBUILD_AFLAGS_MODULE += $(call as-option,-Wa$(comma)-mno-relax) # architectures. It's faster to have GCC emit only aligned accesses. KBUILD_CFLAGS += $(call cc-option,-mstrict-align) +# Ensure that we do not vectorize the kernel code when the `v` extension is +# enabled. This mirrors the `-mno-mmx` et al on x86. +KBUILD_CFLAGS += $(call cc-option,-mno-implicit-float) + ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y) prepare: stack_protector_prepare stack_protector_prepare: prepare0 -- 2.39.0.314.g84b9a713c41-goog _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv