diff --git a/src/share/vm/opto/loopnode.cpp b/src/share/vm/opto/loopnode.cpp index f2ecc275577f4ee528e41c24e9136716a5c932e8..7d4d3dc8c79aec2113c380bc7afd793565e2b6ce 100644 --- a/src/share/vm/opto/loopnode.cpp +++ b/src/share/vm/opto/loopnode.cpp @@ -1538,7 +1538,7 @@ bool IdealLoopTree::beautify_loops( PhaseIdealLoop *phase ) { // If I am a shared header (multiple backedges), peel off the many // backedges into a private merge point and use the merge point as // the one true backedge. - if( _head->req() > 3 ) { + if (_head->req() > 3 && !_irreducible) { // Merge the many backedges into a single backedge but leave // the hottest backedge as separate edge for the following peel. merge_many_backedges( phase ); diff --git a/test/compiler/loopopts/TestBeautifyLoops.java b/test/compiler/loopopts/TestBeautifyLoops.java new file mode 100644 index 0000000000000000000000000000000000000000..c831430ede10044ca820fd80f29e22f2c8804b4d --- /dev/null +++ b/test/compiler/loopopts/TestBeautifyLoops.java @@ -0,0 +1,61 @@ +/* + * Copyright (c) 2020, Huawei Technologies Co. Ltd. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +/** + * @test + * @bug 8240576 + * @summary JVM crashes after transformation in C2 IdealLoopTree::merge_many_backedges + * + * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation + * compiler.loopopts.TestBeautifyLoops + */ + +package compiler.loopopts; + +public class TestBeautifyLoops { + private int mI = 0; + private long mJ = 0; + private float mF = 0f; + + public void testMethod() { + for (int i0 = 0; i0 < 100; i0++) { + if (mF != 0) { + // do nothing + } else { + try { + mJ = Long.MAX_VALUE; + for (int i1 = 0; i1 < 101; i1++) { + for (int i2 = 0; i2 < 102; i2++) { + mI = new Integer(0x1234); + } + } + } catch (Exception ignored) {} + } + } + } + + public static void main(String[] args) { + TestBeautifyLoops obj = new TestBeautifyLoops(); + obj.testMethod(); + } +}