From patchwork Sun Sep 9 18:34:13 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans-Peter Nilsson X-Patchwork-Id: 967795 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=gcc.gnu.org (client-ip=209.132.180.131; helo=sourceware.org; envelope-from=gcc-patches-return-485369-incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=bitrange.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.b="djo5YgCO"; dkim-atps=neutral Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 427fwH5QhPz9s1c for ; Mon, 10 Sep 2018 04:34:23 +1000 (AEST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:subject:message-id:mime-version:content-type; q=dns; s= default; b=S6AUjFQne/pr6uSSG0d0BoW/U/oKSPxHA+mPQd8O5HBnraLNKn26Y PkEByY7vtXt7z0MgU6zPf0wemYM/yUmqUysJiwP5i5w0dt6qyW2o4TZxx3mQiZqY fhLpIRUrsZ9ck9mhREK/I05hSNtqDM73IRyCQjJX3ZQfnd/R1ZQxbs= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:subject:message-id:mime-version:content-type; s= default; bh=jM1CphwpRXIxIArmR1k7ngzcNpM=; b=djo5YgCOyvEVT47JCzB7 ngWRtwHLUQKvQWVQr6cx2BaWo2a9DeyaHlwCWmGKpx24Ifg6qkQeB/SfFok+2h/+ MdnPPXZGsnXlU/DiZU8gPeZbQpT8jFZFrbil7rFyXDBQ6B1Bim57mcR6pI73IWEF cnUAyGnGQMeOXI2BUNY+Gp8= Received: (qmail 62427 invoked by alias); 9 Sep 2018 18:34:16 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 62414 invoked by uid 89); 9 Sep 2018 18:34:16 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-11.4 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.2 spammy=allowing, wisely, talk X-HELO: arjuna.pair.com Received: from arjuna.pair.com (HELO arjuna.pair.com) (209.68.5.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sun, 09 Sep 2018 18:34:15 +0000 Received: by arjuna.pair.com (Postfix, from userid 3006) id C2B988A467; Sun, 9 Sep 2018 14:34:13 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by arjuna.pair.com (Postfix) with ESMTP id C25208A43F for ; Sun, 9 Sep 2018 14:34:13 -0400 (EDT) Date: Sun, 9 Sep 2018 14:34:13 -0400 (EDT) From: Hans-Peter Nilsson To: gcc-patches@gcc.gnu.org Subject: Committed, PR target/86794, MMIX TARGET_HAVE_SPECULATION_SAFE_VALUE: Not needed. Message-ID: User-Agent: Alpine 2.20.16 (BSF 172 2016-09-29) MIME-Version: 1.0 X-IsSubscribed: yes The mythical MMIX hardware engineers have wisely understood the need to automatically disable speculation when a speculated execution path transitions to kernel mode. There might be mythical talk about using a bit in a configuration register to enable even that, but that's just speculation and some say allowing speculation over such mode transitions would be unresponsible and bad engineering. gcc: PR target/86794 * config/mmix/mmix.c (TARGET_HAVE_SPECULATION_SAFE_VALUE): Redefine to speculation_safe_value_not_needed. brgds, H-P Index: gcc/config/mmix/mmix.c =================================================================== --- gcc/config/mmix/mmix.c (revision 264163) +++ gcc/config/mmix/mmix.c (working copy) @@ -227,6 +224,9 @@ #undef TARGET_CONDITIONAL_REGISTER_USAGE #define TARGET_CONDITIONAL_REGISTER_USAGE mmix_conditional_register_usage +#undef TARGET_HAVE_SPECULATION_SAFE_VALUE +#define TARGET_HAVE_SPECULATION_SAFE_VALUE speculation_safe_value_not_needed + #undef TARGET_RTX_COSTS #define TARGET_RTX_COSTS mmix_rtx_costs #undef TARGET_ADDRESS_COST