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8265938: C2's conditional move optimization does not handle top Phi
Reviewed-by: chagedorn, kvn, iignatyev
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TobiHartmann committed Apr 27, 2021
1 parent 5634f20 commit ab2aec2afbab881ee7c97ad634ac1ded2aa03b73
@@ -718,7 +718,9 @@ Node *PhaseIdealLoop::conditional_move( Node *region ) {
break;
}
}
if (phi == NULL) break;
if (phi == NULL || _igvn.type(phi) == Type::TOP) {
break;
}
if (PrintOpto && VerifyLoopOptimizations) { tty->print_cr("CMOV"); }
// Move speculative ops
wq.push(phi);
@@ -0,0 +1,72 @@
/*
* Copyright (c) 2021, Oracle and/or its affiliates. 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 8265938
* @summary Test conditional move optimization with a TOP PhiNode.
* @library /test/lib
* @run main/othervm -XX:CompileCommand=compileonly,compiler.loopopts.TestCMoveWithDeadPhi::test
* compiler.loopopts.TestCMoveWithDeadPhi
*/

package compiler.loopopts;

import jdk.test.lib.Utils;

public class TestCMoveWithDeadPhi {

static void test(boolean b) {
if (b) {
long l = 42;
for (int i = 0; i < 100; i++) {
if (i < 10) {
l++;
if (i == 5) {
break;
}
}
}

// Infinite loop
for (int j = 0; j < 100; j++) {
j--;
}
}
}

public static void main(String[] args) throws Exception {
// Execute test in own thread because it contains an infinite loop
Thread thread = new Thread() {
public void run() {
for (int i = 0; i < 50_000; ++i) {
test((i % 2) == 0);
}
}
};
// Give thread some time to trigger compilation
thread.setDaemon(true);
thread.start();
Thread.sleep(Utils.adjustTimeout(4000));
}
}
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2019, 2021, Oracle and/or its affiliates. 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
@@ -19,20 +19,22 @@
* 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 8228888
* @summary Test PhaseIdealLoop::has_local_phi_input() with phi input with non-dominating control.
* @library /test/lib
* @compile StrangeControl.jasm
* @run main/othervm -Xbatch -XX:CompileCommand=inline,compiler.loopopts.StrangeControl::test
* compiler.loopopts.TestStrangeControl
*/

package compiler.loopopts;

import jdk.test.lib.Utils;

public class TestStrangeControl {

public static void main(String[] args) throws Exception {
@@ -42,8 +44,9 @@ public void run() {
StrangeControl.test(42);
}
};
thread.setDaemon(true);
thread.start();
// Give thread executing strange control loop enough time to trigger OSR compilation
Thread.sleep(4000);
Thread.sleep(Utils.adjustTimeout(4000));
}
}

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