Mercurial > jdk8-mips64-public > hotspot / changeset

     1.1 --- a/src/share/vm/opto/loopTransform.cpp	Thu Oct 17 13:48:07 2019 +0100
     1.2 +++ b/src/share/vm/opto/loopTransform.cpp	Mon Oct 28 13:29:09 2019 +0800
     1.3 @@ -1,5 +1,5 @@
     1.4  /*
     1.5 - * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
     1.6 + * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
     1.7   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     1.8   *
     1.9   * This code is free software; you can redistribute it and/or modify it
    1.10 @@ -2231,6 +2231,13 @@
    1.11      // We also need to replace the original limit to collapse loop exit.
    1.12      Node* cmp = cl->loopexit()->cmp_node();
    1.13      assert(cl->limit() == cmp->in(2), "sanity");
    1.14 +    // Duplicate cmp node if it has other users
    1.15 +    if (cmp->outcnt() > 1) {
    1.16 +      cmp = cmp->clone();
    1.17 +      cmp = phase->_igvn.register_new_node_with_optimizer(cmp);
    1.18 +      BoolNode *bol = cl->loopexit()->in(CountedLoopEndNode::TestValue)->as_Bool();
    1.19 +      phase->_igvn.replace_input_of(bol, 1, cmp); // put bol on worklist
    1.20 +    }
    1.21      phase->_igvn._worklist.push(cmp->in(2)); // put limit on worklist
    1.22      phase->_igvn.replace_input_of(cmp, 2, exact_limit); // put cmp on worklist
    1.23    }

     2.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     2.2 +++ b/test/compiler/loopopts/TestRemoveEmptyLoop.java	Mon Oct 28 13:29:09 2019 +0800
     2.3 @@ -0,0 +1,53 @@
     2.4 +/*
     2.5 + * Copyright (c) 2019, Huawei Technologies Co. Ltd. All rights reserved.
     2.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     2.7 + *
     2.8 + * This code is free software; you can redistribute it and/or modify it
     2.9 + * under the terms of the GNU General Public License version 2 only, as
    2.10 + * published by the Free Software Foundation.
    2.11 + *
    2.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
    2.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    2.14 + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    2.15 + * version 2 for more details (a copy is included in the LICENSE file that
    2.16 + * accompanied this code).
    2.17 + *
    2.18 + * You should have received a copy of the GNU General Public License version
    2.19 + * 2 along with this work; if not, write to the Free Software Foundation,
    2.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    2.21 + *
    2.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    2.23 + * or visit www.oracle.com if you need additional information or have any
    2.24 + * questions.
    2.25 + */
    2.26 +
    2.27 +/**
    2.28 + * @test
    2.29 + * @bug 8231988
    2.30 + * @summary Unexpected test result caused by C2 IdealLoopTree::do_remove_empty_loop
    2.31 + *
    2.32 + * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation
    2.33 + *      TestRemoveEmptyLoop
    2.34 + */
    2.35 +
    2.36 +public class TestRemoveEmptyLoop {
    2.37 +
    2.38 +    public void test() {
    2.39 +        int i = 34;
    2.40 +        for (; i > 0; i -= 11);
    2.41 +        if (i < 0) {
    2.42 +            // do nothing
    2.43 +        } else {
    2.44 +            throw new RuntimeException("Test failed.");
    2.45 +        }
    2.46 +    }
    2.47 +
    2.48 +    public static void main(String[] args) {
    2.49 +        TestRemoveEmptyLoop _instance = new TestRemoveEmptyLoop();
    2.50 +        for (int i = 0; i < 50000; i++) {
    2.51 +            _instance.test();
    2.52 +        }
    2.53 +        System.out.println("Test passed.");
    2.54 +    }
    2.55 +
    2.56 +}