1 /*
   2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 8046698
  27  * @summary PhiNode inserted between AllocateNode and Initialization node confuses allocation elimination
  28  * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement
  29  *                   compiler.macronodes.TestEliminateAllocationPhi
  30  */
  31 
  32 package compiler.macronodes;
  33 
  34 public class TestEliminateAllocationPhi {
  35 
  36     // This will return I when called from m(0 and once optimized will
  37     // go away but this will confuse escape analysis in m(): it will
  38     // find I as non escaping but non scalar replaceable. In its own
  39     // method so that we can make the profile of the if() branch look
  40     // like it's taken sometimes.
  41     static Integer m2(Integer I, int i) {
  42         for (; i < 10; i=(i+2)*(i+2)) {
  43         }
  44         if (i == 121) {
  45             return II;
  46         }
  47         return I;
  48     }
  49 
  50     static Integer II = new Integer(42);
  51 
  52     static int m(int[] integers, boolean flag) {
  53         int j = 0;
  54         while(true) {
  55             try {
  56                 int k = integers[j++];
  57                 // A branch that will cause loop unswitching
  58                 if (flag) {
  59                     k += 42;
  60                 }
  61                 if (k < 1000) {
  62                     throw new Exception();
  63                 }
  64                 // Because of the try/catch the Allocate node for this
  65                 // new will be in the loop while the Initialization
  66                 // node will be outside the loop. When loop
  67                 // unswitching happens, the Allocate node will be
  68                 // cloned and the results of both will be inputs to a
  69                 // Phi that will be between the Allocate nodes and the
  70                 // Initialization nodes.
  71                 Integer I = new Integer(k);
  72 
  73                 I = m2(I, 0);
  74 
  75                 int i = I.intValue();
  76                 return i;
  77             } catch(Exception e) {
  78             }
  79         }
  80     }
  81 
  82     static public void main(String[] args) {
  83         for (int i = 0; i < 5000; i++) {
  84             m2(null, 1);
  85         }
  86 
  87         int[] integers = { 2000 };
  88         for (int i = 0; i < 6000; i++) {
  89             m(integers, (i%2) == 0);
  90         }
  91         int[] integers2 = { 1, 2, 3, 4, 5, 2000 };
  92         for (int i = 0; i < 10000; i++) {
  93             m(integers2, (i%2) == 0);
  94         }
  95     }
  96 }