From patchwork Fri Feb 2 09:09:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andi Kleen X-Patchwork-Id: 1894408 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=a8RTcQGs; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=8.43.85.97; helo=server2.sourceware.org; envelope-from=gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=patchwork.ozlabs.org) Received: from server2.sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TR97p3H5pz1yQ0 for ; Fri, 2 Feb 2024 20:14:14 +1100 (AEDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 49E3E3857C61 for ; Fri, 2 Feb 2024 09:14:12 +0000 (GMT) X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from eggs.gnu.org (eggs.gnu.org [IPv6:2001:470:142:3::10]) by sourceware.org (Postfix) with ESMTPS id 555583858403 for ; Fri, 2 Feb 2024 09:13:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 555583858403 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=linux.intel.com Authentication-Results: sourceware.org; spf=none smtp.mailfrom=linux.intel.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 555583858403 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2001:470:142:3::10 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1706865221; cv=none; b=L5kon3nbObU5hrupfgKTf3upv01QSRrOmfsCsV4VLfsGZPQ2aMVu3AfkkAIPTz/1HHVktKozwzxsvVQ3sAgiCaLB0E1NVQz79LenWEnAJFBYe7pfNXGD5Xb4tmVHHz+L4BBKEa/u8af1juu33mSD5SHdi0Rbfk/UoJde01IwRUc= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1706865221; c=relaxed/simple; bh=TQtJ4xrbM/NlmgbLgcGU7LuH747oYs4I75qnxSx1uiU=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=uy7oJAmVMgw+2wNLAbvAc0mBvVaiWXeywU3/ZA5Xw4WEsZ4lMCFhPUuMIksN/+XV5GsFVFdjJWgCPBCatcdyVFmbQ5P6PiL8d1KDq/jjEVfPzRCWlcnR2eiBWKMfP31K+ZXbtBcOGYcsXLafz7E4QYVx8wf6izmxX08fdlBKw8M= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from mgamail.intel.com ([192.198.163.12]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rVpc8-0004Dc-Rr for gcc-patches@gnu.org; Fri, 02 Feb 2024 04:13:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1706865216; x=1738401216; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TQtJ4xrbM/NlmgbLgcGU7LuH747oYs4I75qnxSx1uiU=; b=a8RTcQGsFIhS059oNchqhf9uhjcR89y/udQRl5uTobJnaUqJFGfIJfN6 FXHeEm1CRn1KL0KmhmAy5154MQY15k1IUQAOC9DTqX1R8nwEMwY1laF44 pT6bSQ67Wxap/LPLXVHvBxXSDyJYSxa9ajKhWjI9TwQklUP6/HJPlO6O0 E/wIVfG8QU3cU8yIiVaOS/z3BTsYg/6fcVGZm2p6+yWGEAufyJH/ptwfk K5/JY/CkSqP9ihHxvxyNIRn4GT/RStOwKYO26sygXWvk5j7gc5deJtu29 ysuFfC0TXY368se3ONtnE5F4gYB2GZB+lvr+IbJ+AxHV8U32a52fj/Xm4 w==; X-IronPort-AV: E=McAfee;i="6600,9927,10971"; a="3942945" X-IronPort-AV: E=Sophos;i="6.05,237,1701158400"; d="scan'208";a="3942945" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2024 01:13:30 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,237,1701158400"; d="scan'208";a="23318057" Received: from tassilo.jf.intel.com ([10.54.38.190]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2024 01:13:30 -0800 From: Andi Kleen To: gcc-patches@gnu.org Cc: Andi Kleen Subject: [PATCH v4 1/5] Improve must tail in RTL backend Date: Fri, 2 Feb 2024 01:09:16 -0800 Message-ID: <20240202091322.1898280-2-ak@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240202091322.1898280-1-ak@linux.intel.com> References: <20240202091322.1898280-1-ak@linux.intel.com> MIME-Version: 1.0 Received-SPF: none client-ip=192.198.163.12; envelope-from=ak@linux.intel.com; helo=mgamail.intel.com X-Spam_score_int: -32 X-Spam_score: -3.3 X-Spam_bar: --- X-Spam_report: (-3.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.292, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-Spam-Status: No, score=-12.6 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, GIT_PATCH_0, SPF_HELO_PASS, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org - Give error messages for all causes of non sibling call generation - Don't override choices of other non sibling call checks with must tail. This causes ICEs. The must tail attribute now only overrides flag_optimize_sibling_calls locally. - Error out when tree-tailcall failed to mark a must-tail call sibcall. In this case it doesn't know the true reason and only gives a vague message (this could be improved, but it's already useful without that) tree-tailcall usually fails without optimization, so must adjust the existing must-tail plugin test to specify -O2. PR83324 gcc/ChangeLog: * calls.cc (expand_call): Fix mustcall implementation. gcc/testsuite/ChangeLog: * gcc.dg/plugin/must-tail-call-1.c: Adjust. --- gcc/calls.cc | 30 ++++++++++++------- .../gcc.dg/plugin/must-tail-call-1.c | 1 + 2 files changed, 21 insertions(+), 10 deletions(-) diff --git a/gcc/calls.cc b/gcc/calls.cc index 01f447347437..60a43f5d36a8 100644 --- a/gcc/calls.cc +++ b/gcc/calls.cc @@ -2650,7 +2650,9 @@ expand_call (tree exp, rtx target, int ignore) /* The type of the function being called. */ tree fntype; bool try_tail_call = CALL_EXPR_TAILCALL (exp); - bool must_tail_call = CALL_EXPR_MUST_TAIL_CALL (exp); + /* tree-tailcall decided not to do tail calls. Error for the musttail case. */ + if (!try_tail_call) + maybe_complain_about_tail_call (exp, "other reasons"); int pass; /* Register in which non-BLKmode value will be returned, @@ -3021,10 +3023,22 @@ expand_call (tree exp, rtx target, int ignore) pushed these optimizations into -O2. Don't try if we're already expanding a call, as that means we're an argument. Don't try if there's cleanups, as we know there's code to follow the call. */ - if (currently_expanding_call++ != 0 - || (!flag_optimize_sibling_calls && !CALL_FROM_THUNK_P (exp)) - || args_size.var - || dbg_cnt (tail_call) == false) + if (currently_expanding_call++ != 0) + { + maybe_complain_about_tail_call (exp, "inside another call"); + try_tail_call = 0; + } + if (!flag_optimize_sibling_calls + && !CALL_FROM_THUNK_P (exp) + && !CALL_EXPR_MUST_TAIL_CALL (exp)) + try_tail_call = 0; + if (args_size.var) + { + /* ??? correct message? */ + maybe_complain_about_tail_call (exp, "stack space needed"); + try_tail_call = 0; + } + if (dbg_cnt (tail_call) == false) try_tail_call = 0; /* Workaround buggy C/C++ wrappers around Fortran routines with @@ -3045,15 +3059,11 @@ expand_call (tree exp, rtx target, int ignore) if (MEM_P (*iter)) { try_tail_call = 0; + maybe_complain_about_tail_call (exp, "hidden string length argument"); break; } } - /* If the user has marked the function as requiring tail-call - optimization, attempt it. */ - if (must_tail_call) - try_tail_call = 1; - /* Rest of purposes for tail call optimizations to fail. */ if (try_tail_call) try_tail_call = can_implement_as_sibling_call_p (exp, diff --git a/gcc/testsuite/gcc.dg/plugin/must-tail-call-1.c b/gcc/testsuite/gcc.dg/plugin/must-tail-call-1.c index 3a6d4cceaba7..44af361e2925 100644 --- a/gcc/testsuite/gcc.dg/plugin/must-tail-call-1.c +++ b/gcc/testsuite/gcc.dg/plugin/must-tail-call-1.c @@ -1,4 +1,5 @@ /* { dg-do compile { target tail_call } } */ +/* { dg-options "-O2" } */ /* { dg-options "-fdelayed-branch" { target sparc*-*-* } } */ extern void abort (void);