From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by sourceware.org (Postfix) with ESMTPS id C06703858D35 for ; Tue, 23 May 2023 09:55:34 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org C06703858D35 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id C3F6F228BC for ; Tue, 23 May 2023 09:55:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1684835733; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type; bh=oIet7jUdL1yrxi8CzLbzlMaoYaW0BWACbr0YUKYISXE=; b=WouUXtrDm40NhC6UvVN3SD49V5lPzHlxLZ4yVqLu/m4TryalHaHx+9nFBem9/CsFu2csHl 2NSvudTQMYI82C5LPiNq4zspAhMCre4ubRnl4plbb3g7YIqI2G3JBMnkvPpt8BWeuGqodJ d1q+zozK33ltmB3SMnhdx49tsnod1LE= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1684835733; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type; bh=oIet7jUdL1yrxi8CzLbzlMaoYaW0BWACbr0YUKYISXE=; b=Y0NPgumKf1oNs7CbSXJOU8mIlcJRjyUJRKwr/oxnBPbY/qvJbkWT8TOpjYQBTJejz6BTdD 8df+n88NEbH9WxCw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id B1C0713588 for ; Tue, 23 May 2023 09:55:33 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id JdtAKpWNbGQxYgAAMHmgww (envelope-from ) for ; Tue, 23 May 2023 09:55:33 +0000 Date: Tue, 23 May 2023 11:55:33 +0200 (CEST) From: Richard Biener To: gcc-patches@gcc.gnu.org Subject: [PATCH] tree-optimization/109849 - missed code hoisting MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Message-Id: <20230523095533.B1C0713588@imap2.suse-dmz.suse.de> X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,SPF_HELO_NONE,SPF_PASS,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 List-Id: The following fixes code hoisting to properly consider ANTIC_OUT instead of ANTIC_IN. That's a bit expensive to re-compute but since we no longer iterate we're doing this only once per BB which should be acceptable. This avoids missing hoistings to the end of blocks where something in the block clobbers the hoisted value. Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed. PR tree-optimization/109849 * tree-ssa-pre.cc (do_hoist_insertion): Compute ANTIC_OUT and use that to determine what to hoist. * gcc.dg/tree-ssa/ssa-hoist-8.c: New testcase. --- gcc/testsuite/gcc.dg/tree-ssa/ssa-hoist-8.c | 22 ++++++++++ gcc/tree-ssa-pre.cc | 48 ++++++++++++++++++--- 2 files changed, 64 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/ssa-hoist-8.c diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-hoist-8.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-hoist-8.c new file mode 100644 index 00000000000..66bb48e0dc1 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-hoist-8.c @@ -0,0 +1,22 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-pre-stats" } */ + +int mem; +void foo (); +int bar (int flag) +{ + int res; + foo (); + /* Hoist the load of mem here even though foo () clobbers it. */ + if (flag) + res = mem; + else + { + res = mem; + mem = 2; + } + return res; +} + +/* { dg-final { scan-tree-dump "HOIST inserted: 1" "pre" } } */ +/* { dg-final { scan-tree-dump-times " = mem;" 1 "pre" } } */ diff --git a/gcc/tree-ssa-pre.cc b/gcc/tree-ssa-pre.cc index 1f7eea93c16..d56431b4145 100644 --- a/gcc/tree-ssa-pre.cc +++ b/gcc/tree-ssa-pre.cc @@ -3622,19 +3622,51 @@ do_hoist_insertion (basic_block block) && stmt_ends_bb_p (gsi_stmt (last))) return false; - /* Compute the set of hoistable expressions from ANTIC_IN. First compute + /* We have multiple successors, compute ANTIC_OUT by taking the intersection + of all of ANTIC_IN translating through PHI nodes. Note we do not have to + worry about iteration stability here so just intersect the expression sets + as well. This is a simplification of what we do in compute_antic_aux. */ + bitmap_set_t ANTIC_OUT = bitmap_set_new (); + bool first = true; + FOR_EACH_EDGE (e, ei, block->succs) + { + if (first) + { + phi_translate_set (ANTIC_OUT, ANTIC_IN (e->dest), e); + first = false; + } + else if (!gimple_seq_empty_p (phi_nodes (e->dest))) + { + bitmap_set_t tmp = bitmap_set_new (); + phi_translate_set (tmp, ANTIC_IN (e->dest), e); + bitmap_and_into (&ANTIC_OUT->values, &tmp->values); + bitmap_and_into (&ANTIC_OUT->expressions, &tmp->expressions); + bitmap_set_free (tmp); + } + else + { + bitmap_and_into (&ANTIC_OUT->values, &ANTIC_IN (e->dest)->values); + bitmap_and_into (&ANTIC_OUT->expressions, + &ANTIC_IN (e->dest)->expressions); + } + } + + /* Compute the set of hoistable expressions from ANTIC_OUT. First compute hoistable values. */ bitmap_set hoistable_set; - /* A hoistable value must be in ANTIC_IN(block) + /* A hoistable value must be in ANTIC_OUT(block) but not in AVAIL_OUT(BLOCK). */ bitmap_initialize (&hoistable_set.values, &grand_bitmap_obstack); bitmap_and_compl (&hoistable_set.values, - &ANTIC_IN (block)->values, &AVAIL_OUT (block)->values); + &ANTIC_OUT->values, &AVAIL_OUT (block)->values); /* Short-cut for a common case: hoistable_set is empty. */ if (bitmap_empty_p (&hoistable_set.values)) - return false; + { + bitmap_set_free (ANTIC_OUT); + return false; + } /* Compute which of the hoistable values is in AVAIL_OUT of at least one of the successors of BLOCK. */ @@ -3652,11 +3684,14 @@ do_hoist_insertion (basic_block block) /* Short-cut for a common case: availout_in_some is empty. */ if (bitmap_empty_p (&availout_in_some)) - return false; + { + bitmap_set_free (ANTIC_OUT); + return false; + } /* Hack hoitable_set in-place so we can use sorted_array_from_bitmap_set. */ bitmap_move (&hoistable_set.values, &availout_in_some); - hoistable_set.expressions = ANTIC_IN (block)->expressions; + hoistable_set.expressions = ANTIC_OUT->expressions; /* Now finally construct the topological-ordered expression set. */ vec exprs = sorted_array_from_bitmap_set (&hoistable_set); @@ -3731,6 +3766,7 @@ do_hoist_insertion (basic_block block) } exprs.release (); + bitmap_set_free (ANTIC_OUT); return new_stuff; } -- 2.35.3