From patchwork Sun Nov 22 23:21:49 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom de Vries X-Patchwork-Id: 547358 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org 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 D2C2C140213 for ; Mon, 23 Nov 2015 10:23:00 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.b=EvmhOC0K; dkim-atps=neutral DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:to :from:subject:cc:message-id:date:mime-version:content-type; q= dns; s=default; b=Dl3BGjci+tw9ohIzaSVIYHnCxsDvAqKS82bC8nHwxLQVfk VKWBUn5oIEwgBNuX1iR+fcV0/n8PUjDrwHSdJfoZq1hEj5/f+xNhSzmYGIFDuaib vwqEE3feRLZbt4vg10k7vktZ53rmGR6885X9UdQaktvHXa2kFD/uFyMaidy4Q= 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:to :from:subject:cc:message-id:date:mime-version:content-type; s= default; bh=nUowjoZRokCWgq/poRk+/cqNh3g=; b=EvmhOC0Ky1wzViH3xtV+ yN7t32lSG6SGkG4s7RhjEoenfHRc692au5/PO5jkbtmyUc9ne3vdX3wCBwQ9BkbF gxNPIoCYlChTneEo3kyV7OQXALsGCvQibND80RXP3izTSy4h5Lsn1MOQxS7ycPMO 9Jlo0sEmwaGM+PrXBZO02DQ= Received: (qmail 121184 invoked by alias); 22 Nov 2015 23:22:53 -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 121170 invoked by uid 89); 22 Nov 2015 23:22:52 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL, BAYES_00, RP_MATCHES_RCVD, SPF_PASS autolearn=ham version=3.3.2 X-HELO: fencepost.gnu.org Received: from fencepost.gnu.org (HELO fencepost.gnu.org) (208.118.235.10) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Sun, 22 Nov 2015 23:22:51 +0000 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39991) by fencepost.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1a0dy5-0006Jo-31 for gcc-patches@gnu.org; Sun, 22 Nov 2015 18:22:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a0dy0-0001Oa-IO for gcc-patches@gnu.org; Sun, 22 Nov 2015 18:22:48 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:57013) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a0dy0-0001OI-CP for gcc-patches@gnu.org; Sun, 22 Nov 2015 18:22:44 -0500 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=SVR-IES-FEM-01.mgc.mentorg.com) by relay1.mentorg.com with esmtp id 1a0dxt-0002xF-D9 from Tom_deVries@mentor.com ; Sun, 22 Nov 2015 15:22:37 -0800 Received: from [127.0.0.1] (137.202.0.76) by SVR-IES-FEM-01.mgc.mentorg.com (137.202.0.104) with Microsoft SMTP Server id 14.3.224.2; Sun, 22 Nov 2015 23:22:36 +0000 To: "gcc-patches@gnu.org" From: Tom de Vries Subject: [PATCH] Check NULL loop->latch in verify_loop_structure CC: Jakub Jelinek , Richard Biener Message-ID: <56524E0D.7000203@mentor.com> Date: Mon, 23 Nov 2015 00:21:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Windows NT kernel [generic] [fuzzy] X-Received-From: 192.94.38.131 Hi, In verify_loop_structure, we stop checking the latch once we find that it's NULL. This patch tries a bit harder: - if !LOOPS_MAY_HAVE_MULTIPLE_LATCHES, we don't allow a NULL latch - if LOOPS_MAY_HAVE_MULTIPLE_LATCHES, we check that indeed there's no single loop latch. As a consequence of adding this check, I needed to fix expand_omp_for_generic, which missed an initialization of a loop latch. Bootstrapped and reg-tested on x86_64. OK for stage3 trunk? Thanks, - Tom Check NULL loop->latch in verify_loop_structure 2015-11-22 Tom de Vries * cfgloop.c (find_single_latch): New function, factored out of ... (flow_loops_find): ... here. (verify_loop_structure): Verify validity of a NULL loop->latch. * cfgloop.h (find_single_latch): Declare. * omp-low.c (expand_omp_for_generic): Initialize latch of orig_loop. --- gcc/cfgloop.c | 65 +++++++++++++++++++++++++++++++++++++++++------------------ gcc/cfgloop.h | 1 + gcc/omp-low.c | 1 + 3 files changed, 47 insertions(+), 20 deletions(-) diff --git a/gcc/cfgloop.c b/gcc/cfgloop.c index bf00e0e..b610860 100644 --- a/gcc/cfgloop.c +++ b/gcc/cfgloop.c @@ -388,6 +388,33 @@ bb_loop_header_p (basic_block header) return false; } +/* Return the latch block for this header block, if it has just a single one. + Otherwise, return NULL. */ + +basic_block +find_single_latch (struct loop* loop) +{ + basic_block header = loop->header; + edge_iterator ei; + edge e; + basic_block latch = NULL; + + FOR_EACH_EDGE (e, ei, header->preds) + { + basic_block cand = e->src; + if (!flow_bb_inside_loop_p (loop, cand)) + continue; + + if (latch != NULL) + /* More than one latch edge. */ + return NULL; + + latch = cand; + } + + return latch; +} + /* Find all the natural loops in the function and save in LOOPS structure and recalculate loop_father information in basic block structures. If LOOPS is non-NULL then the loop structures for already recorded loops @@ -482,29 +509,10 @@ flow_loops_find (struct loops *loops) { struct loop *loop = larray[i]; basic_block header = loop->header; - edge_iterator ei; - edge e; flow_loop_tree_node_add (header->loop_father, loop); loop->num_nodes = flow_loop_nodes_find (loop->header, loop); - - /* Look for the latch for this header block, if it has just a - single one. */ - FOR_EACH_EDGE (e, ei, header->preds) - { - basic_block latch = e->src; - - if (flow_bb_inside_loop_p (loop, latch)) - { - if (loop->latch != NULL) - { - /* More than one latch edge. */ - loop->latch = NULL; - break; - } - loop->latch = latch; - } - } + loop->latch = find_single_latch (loop); } return loops; @@ -1440,6 +1448,23 @@ verify_loop_structure (void) err = 1; } } + else + { + if (loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)) + { + if (find_single_latch (loop) != NULL) + { + error ("loop %d%'s latch is missing", i); + err = 1; + } + } + else + { + error ("loop %d%'s latch is missing, and loops may not have" + " multiple latches", i); + err = 1; + } + } if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) { if (!single_succ_p (loop->latch)) diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h index ee73bf9..7faf591 100644 --- a/gcc/cfgloop.h +++ b/gcc/cfgloop.h @@ -270,6 +270,7 @@ bool mark_irreducible_loops (void); void release_recorded_exits (function *); void record_loop_exits (void); void rescan_loop_exit (edge, bool, bool); +basic_block find_single_latch (struct loop*); /* Loop data structure manipulation/querying. */ extern void flow_loop_tree_node_add (struct loop *, struct loop *); diff --git a/gcc/omp-low.c b/gcc/omp-low.c index b47864e..00e314d6 100644 --- a/gcc/omp-low.c +++ b/gcc/omp-low.c @@ -8900,6 +8900,7 @@ expand_omp_for_generic (struct omp_region *region, orig_loop->header = l1_bb; /* The loop may have multiple latches. */ add_loop (orig_loop, new_loop); + orig_loop->latch = find_single_latch (orig_loop); } } }