8020215: Different execution plan when using JIT vs interpreter

Summary: fix bytecode analyzer
Reviewed-by: twisti

src/share/vm/ci/bcEscapeAnalyzer.cpp

@@ -138,6 +138,16 @@ bool BCEscapeAnalyzer::is_arg_stack(ArgumentMap vars){
   return false;
 }
 
+// return true if all argument elements of vars are returned
+bool BCEscapeAnalyzer::returns_all(ArgumentMap vars) {
+  for (int i = 0; i < _arg_size; i++) {
+    if (vars.contains(i) && !_arg_returned.test(i)) {
+      return false;
+    }
+  }
+  return true;
+}
+
 void BCEscapeAnalyzer::clear_bits(ArgumentMap vars, VectorSet &bm) {
   for (int i = 0; i < _arg_size; i++) {
     if (vars.contains(i)) {
@@ -166,6 +176,11 @@ void BCEscapeAnalyzer::set_global_escape(ArgumentMap vars, bool merge) {
     if (vars.contains_unknown() || vars.contains_vars()) {
       _return_allocated = false;
     }
+    if (_return_local && vars.contains_vars() && !returns_all(vars)) {
+      // Return result should be invalidated if args in new
+      // state are not recorded in return state.
+      _return_local = false;
+    }
   }
 }
 

src/share/vm/ci/bcEscapeAnalyzer.hpp

@@ -80,6 +80,7 @@ class BCEscapeAnalyzer : public ResourceObj {
   void set_returned(ArgumentMap vars);
   bool is_argument(ArgumentMap vars);
   bool is_arg_stack(ArgumentMap vars);
+  bool returns_all(ArgumentMap vars);
   void clear_bits(ArgumentMap vars, VectorSet &bs);
   void set_method_escape(ArgumentMap vars);
   void set_global_escape(ArgumentMap vars, bool merge = false);

test/compiler/EscapeAnalysis/Test8020215.java

+/*
+ * Copyright (c) 2013, 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 8020215
+ * @summary Different execution plan when using JIT vs interpreter
+ * @run main Test8020215
+ */
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Test8020215 {
+    public static class NamedObject {
+        public int id;
+        public String name;
+        public NamedObject(int id, String name) {
+            this.id = id;
+            this.name = name;
+        }
+    }
+
+    public static class NamedObjectList {
+        public List<NamedObject> namedObjectList = new ArrayList<NamedObject>();
+
+        public NamedObject getBest(int id) {
+            NamedObject bestObject = null;
+            for (NamedObject o : namedObjectList) {
+                bestObject = id==o.id ? getBetter(bestObject, o) : bestObject;
+            }
+            return (bestObject != null) ? bestObject : null;
+        }
+
+        private static NamedObject getBetter(NamedObject p1, NamedObject p2) {
+            return (p1 == null) ? p2 : (p2 == null) ? p1 : (p2.name.compareTo(p1.name) >= 0) ? p2 : p1;
+        }
+    }
+
+    static void test(NamedObjectList b, int i) {
+        NamedObject x = b.getBest(2);
+        // test
+        if (x == null) {
+            throw new RuntimeException("x should never be null here! (i=" + i + ")");
+        }
+    }
+
+    public static void main(String[] args) {
+        // setup
+        NamedObjectList b = new NamedObjectList();
+        for (int i = 0; i < 10000; i++) {
+            b.namedObjectList.add(new NamedObject(1, "2012-12-31"));
+        }
+        b.namedObjectList.add(new NamedObject(2, "2013-12-31"));
+
+        // execution
+        for (int i = 0; i < 12000; i++) {
+            test(b, i);
+        }
+        System.out.println("PASSED");
+    }
+}