8215410: Regression test for JDK-8214994
Summary: Added a regression test for 8214994 which was fixed by accident with 8211451.
Reviewed-by: kvn
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/compiler/loopopts/TestSplitIfOpaque1.java Mon Dec 17 08:25:57 2018 +0100
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2018, 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 8214994
+ * @summary The split-if optimization fails because an unexpected Opaque1 is encountered.
+ * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-UseOnStackReplacement -XX:-BackgroundCompilation
+ * compiler.loopopts.TestSplitIfOpaque1
+ */
+
+package compiler.loopopts;
+
+public class TestSplitIfOpaque1 {
+
+ static class MyClass {
+ int f;
+ MyClass(int f) {
+ this.f = f;
+ }
+ }
+
+ // The inner loop is found to be a counted loop and a loop limit check
+ // is added by updating the Opaque1 input of the predicate template.
+ // This Opaque1 node is then pushed upwards to before the predicates of
+ // the outer loop and ends up right after the second 'if (b)'.
+ // The split-if optimization kicks in and splits the first predicate of
+ // the outer loop (an "obj != NULL" check) through the 'if (b)' region.
+ // We fail because the region contains an unexpected Opaque1 node.
+ static int test1(boolean b, int limit, MyClass obj) {
+ int res = 0;
+ MyClass notNull = new MyClass(42);
+ if (b) {
+ limit = 100;
+ }
+ if (b) {
+ obj = notNull;
+ }
+ for (int i = 0; i < 1000; ++i) {
+ res += obj.f;
+ for (int j = 0; j <= limit; ++j) {
+ // Empty
+ }
+ }
+ return res;
+ }
+
+ // Same as test1 but triggers slightly different failure mode
+ static int test2(boolean b, int limit, MyClass obj, int[] array) {
+ int res = 0;
+ MyClass notNull = new MyClass(12);
+ if (b) {
+ limit = 100;
+ }
+ if (b) {
+ obj = notNull;
+ }
+ for (int i = 0; i < 1000; ++i) {
+ res += obj.f;
+ for (int j = 0; j <= limit; ++j) {
+ array[j] = j;
+ }
+ }
+ return res;
+ }
+
+ public static void main(String[] args) {
+ MyClass obj = new MyClass(42);
+ int[] array = new int[101];
+ for (int i = 0; i < 20_000; i++) {
+ test1(true, 50, obj);
+ test1(false, 100, obj);
+ test2(true, 50, obj, array);
+ test2(false, 100, obj, array);
+ }
+ }
+}