test/hotspot/jtreg/compiler/loopopts/TestRemoveMainPostLoops.java
changeset 59022 ff1887930406
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/compiler/loopopts/TestRemoveMainPostLoops.java	Tue Nov 12 10:16:04 2019 +0100
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2019, 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 8233529
+ * @summary Verify that correct loops are selected when trying to remove main/post.
+ * @run main/othervm -XX:-TieredCompilation -Xbatch
+ *                   -XX:CompileCommand=compileonly,compiler.loopopts.TestRemoveMainPostLoops::test
+ *                   compiler.loopopts.TestRemoveMainPostLoops
+ */
+
+package compiler.loopopts;
+
+public class TestRemoveMainPostLoops {
+    static int cnt1 = 0;
+    int cnt2 = 0;
+
+    void testCallee() {
+        // (5) Only main and post loops are created (no pre loop -> "PeelMainPost") and main is unrolled.
+        for (int i = 0; i < 100; ++i) {
+            // (4) Inner loop is fully unrolled and removed.
+            for (int j = 0; j < 10; ++j) {
+                cnt1 += j;
+            }
+        }
+    }
+
+    void test() {
+        for (int i = 0; i < 10_000; ++i) {
+            // (0) testCallee method is inlined
+            testCallee();
+            cnt2 = 0;
+            // (1) OSR compilation is triggered in this loop.
+            // (2) Pre-/main-/post loops are created.
+            // (3) Main and post loops found empty and removed.
+            // (6) Pre loop is found empty, attempt to remove main and post loop then incorrectly selects main from (5).
+            for (int j = 0; j < 10; ++j) {
+                cnt2 = cnt1 + j;
+            }
+        }
+    }
+
+    public static void main(String[] strArr) {
+        TestRemoveMainPostLoops test = new TestRemoveMainPostLoops();
+        for (int i = 0; i < 100; i++) {
+            cnt1 = 0;
+            test.cnt2 = 0;
+            test.test();
+            if (cnt1 != 45000000 || test.cnt2 != 45000009) {
+                throw new RuntimeException("Incorrect result: " + cnt1 + " " + test.cnt2);
+            }
+        }
+    }
+}