1 /*
   2  * Copyright (c) 2020, 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 8249607
  27  * @summary A LoadNode is pinned in split_if_with_blocks_post() on a loop exit node x that is part of a strip mined loop. It has a late control y outside
  28             the outer strip mined loop. After pre-main-post, the dominator chain of y does not include x anymore resulting in an assertion failure.
  29  * @run main/othervm -Xbatch -XX:CompileCommand=compileonly,compiler.loopopts.TestSplitIfPinnedLoadInStripMinedLoop::*
  30  *                   compiler.loopopts.TestSplitIfPinnedLoadInStripMinedLoop
  31  */
  32 package compiler.loopopts;
  33 
  34 public class TestSplitIfPinnedLoadInStripMinedLoop {
  35 
  36     public boolean bFld = false;
  37     public short sFld = 4;
  38     public static int iFld = 5;
  39     public static float fFld= 6.0f;
  40     public static int iArrFld[] = new int[400];
  41 
  42     public void test() {
  43         int x = 7;
  44         int y = 8;
  45         int a = 9;
  46         float f = 10.0f;
  47         double d = 11.0f;
  48         double dArr[] = new double[400];
  49 
  50         for (int i = 16; i < 350; i++) {
  51             for (int j = 1; j < 75; j++) {
  52                 for (int k = 1; k < 3; k++) {
  53                 }
  54                 f = j * 6;
  55                 y = j;
  56                 try {
  57                     x = (y / 148);
  58                 } catch (ArithmeticException a_e) {}
  59                 if (bFld) {
  60                     break;
  61                 }
  62                 dArr[1] = 4;
  63             }
  64             for (int k = 75; k > i; k--) {
  65                 iArrFld[k] = 5;
  66             }
  67             for (int k = 4; k < 75; k++) {
  68                 f -= fFld;
  69                 // The LoadSNode for sFld is cloned in split_if_with_blocks_post() for each use such that they can float out of the loop. All control
  70                 // inputs of the clone are set to the latest control of the original LoadSNode which in this case is the StoreSNode for iFld that is
  71                 // aninput to a MergeMemNode which is an input to the SafePointNode in the outer strip mined loop. Both these nodes are not part
  72                 // of the loop body and thus the StoreNode is also not part of the loop anymore. This means that all the new LoadNode clones get
  73                 // the loop exit l inside the outer strip mined loop as control input. Some of these clones (**) have a late control outside of
  74                 // this outer strip mined loop. The dominator chain from the controls nodes of (**) contain l. However, after pre-main-post, we
  75                 // insert additional Region nodes but do not account for these control inputs of the LoadSNodes. They remain unchanged and still
  76                 // have l as control input. As a consequence, we do not find l on the dominator chains from the control nodes of (**) anymore
  77                 // resulting in a dominator assertion failure.
  78                 iFld = sFld;
  79             }
  80             switch ((i % 8) + 27) {
  81             case 27:
  82                 if (bFld) {
  83                     for (a = 1; a < 75; a++) {
  84                         iFld += 6; // (**)
  85                     }
  86                 } else {
  87                     d -= x;
  88                 }
  89                 break;
  90             case 28:
  91                 iFld = y;
  92                 // Fall through
  93             case 33:
  94             case 34:
  95                 iFld -= (int)d; // (**)
  96                 break;
  97             }
  98         }
  99     }
 100     public static void main(String[] strArr) {
 101         TestSplitIfPinnedLoadInStripMinedLoop t = new TestSplitIfPinnedLoadInStripMinedLoop();
 102         for (int i = 0; i < 10; i++) {
 103             t.test();
 104         }
 105     }
 106 }