From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by sourceware.org (Postfix) with ESMTPS id 942B2388DD42 for ; Thu, 15 Dec 2022 12:58:38 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 942B2388DD42 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 relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 85AB85BCF4 for ; Thu, 15 Dec 2022 12:58:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1671109117; h=from:from:reply-to:date:date:to:to:cc:mime-version:mime-version: content-type:content-type; bh=ffvycuEwyPdCLJJ6comok2PX1iQVLUfJ8wtvrFPW96o=; b=qLb0r5wooVK//b4Ciqxa3iV6w7+XQDWacE5OY0w6ZsV5iWRGiY/kQAIOpzHQtQHsYEC6HS 5p77isrkzktanE2ceuf2yuUfYdM4nuGJhh/2mEPuxIyaMpJbU/erwEoFbS+UdfUBmPFEPr CCMpdVzOk8Kx7KLj+0Bzw4J71MLwAUk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1671109117; h=from:from:reply-to:date:date:to:to:cc:mime-version:mime-version: content-type:content-type; bh=ffvycuEwyPdCLJJ6comok2PX1iQVLUfJ8wtvrFPW96o=; b=zVx494+Gr/ub3dkySaKZ0Pzo6Nxfxt3JIVvawuLyYw46ZwVU59v6ibtc6eWya2KtgaYqDl AYIITUZu/r8yHRAw== Received: from wotan.suse.de (wotan.suse.de [10.160.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 7FED32C141 for ; Thu, 15 Dec 2022 12:58:37 +0000 (UTC) Date: Thu, 15 Dec 2022 12:58:37 +0000 (UTC) From: Richard Biener To: gcc-patches@gcc.gnu.org Subject: [PATCH] middle-end/108086 - avoid quadraticness in copy_edges_for_bb User-Agent: Alpine 2.22 (LSU 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Status: No, score=-10.6 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,MISSING_MID,SPF_HELO_NONE,SPF_PASS,TXREP 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: Message-ID: <20221215125837.bCIhCf9e3IBR4QxAdoeMws76fz_zpXyY0LIL0zfuPEw@z> For the testcase in PR108086 it's visible that we split blocks multiple times when inlining and that causes us to adjust the block tail stmt BBs multiple times, once for each split. The fix is to walk backwards and split from the tail instead. For a reduced testcase this improves compile-time at -O by 4%. Bootstrap and regtest running on x86_64-unknown-linux-gnu. PR middle-end/108086 * tree-inline.cc (copy_edges_for_bb): Walk stmts backwards for splitting the block to avoid quadratic behavior with setting stmts BB on multliple splits. --- gcc/tree-inline.cc | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/gcc/tree-inline.cc b/gcc/tree-inline.cc index 7b507dd2a38..79897f41e86 100644 --- a/gcc/tree-inline.cc +++ b/gcc/tree-inline.cc @@ -2569,13 +2569,17 @@ copy_edges_for_bb (basic_block bb, profile_count num, profile_count den, && !old_edge->src->aux) new_bb->count -= old_edge->count ().apply_scale (num, den); - for (si = gsi_start_bb (new_bb); !gsi_end_p (si);) + /* Walk stmts from end to start so that splitting will adjust the BB + pointer for each stmt at most once, even when we split the block + multiple times. */ + bool seen_nondebug = false; + for (si = gsi_last_bb (new_bb); !gsi_end_p (si);) { bool can_throw, nonlocal_goto; gimple *copy_stmt = gsi_stmt (si); /* Do this before the possible split_block. */ - gsi_next (&si); + gsi_prev (&si); /* If this tree could throw an exception, there are two cases where we need to add abnormal edge(s): the @@ -2595,25 +2599,23 @@ copy_edges_for_bb (basic_block bb, profile_count num, profile_count den, if (can_throw || nonlocal_goto) { - if (!gsi_end_p (si)) - { - while (!gsi_end_p (si) && is_gimple_debug (gsi_stmt (si))) - gsi_next (&si); - if (gsi_end_p (si)) - need_debug_cleanup = true; - } - if (!gsi_end_p (si)) - /* Note that bb's predecessor edges aren't necessarily - right at this point; split_block doesn't care. */ + /* If there's only debug insns after copy_stmt don't split + the block but instead mark the block for cleanup. */ + if (!seen_nondebug) + need_debug_cleanup = true; + else { + /* Note that bb's predecessor edges aren't necessarily + right at this point; split_block doesn't care. */ edge e = split_block (new_bb, copy_stmt); - - new_bb = e->dest; - new_bb->aux = e->src->aux; - si = gsi_start_bb (new_bb); + e->dest->aux = new_bb->aux; + seen_nondebug = false; } } + if (!is_gimple_debug (copy_stmt)) + seen_nondebug = true; + bool update_probs = false; if (gimple_code (copy_stmt) == GIMPLE_EH_DISPATCH) -- 2.35.3