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test/compiler/loopopts/TestOverunrolling.java

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   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 8159016
  27  * @requires vm.gc == "Parallel" | vm.gc == "null"
  28  * @summary Tests correct dominator information after over-unrolling a loop.


  29  * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -Xcomp -XX:-TieredCompilation
  30  *                   -XX:-UseG1GC -XX:+UseParallelGC TestOverunrolling

  31  */



  32 public class TestOverunrolling {
  33 
  34     public static Object test(int arg) {
  35         Object arr[] = new Object[3];
  36         int lim = (arg & 3);
  37         // The pre loop is executed for one iteration, initializing p[0].
  38         // The main loop is unrolled twice, initializing p[1], p[2], p[3] and p[4].
  39         // The p[3] and p[4] stores are always out of bounds and removed. However,
  40         // C2 is unable to remove the "over-unrolled", dead main loop. As a result,
  41         // there is a control path from the main loop to the post loop without a
  42         // memory path (because the last store was replaced by TOP). We crash
  43         // because we use a memory edge from a non-dominating region.
  44         for (int i = 0; i < lim; ++i) {
  45             arr[i] = new Object();
  46         }
  47         // Avoid EA
  48         return arr;
  49     }
  50 
  51     public static void main(String args[]) {


   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 8159016

  27  * @summary Tests correct dominator information after over-unrolling a loop.
  28  * @requires vm.gc == "Parallel" | vm.gc == "null"
  29  *
  30  * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -Xcomp -XX:-TieredCompilation
  31  *                   -XX:-UseG1GC -XX:+UseParallelGC
  32  *                   compiler.loopopts.TestOverunrolling
  33  */
  34 
  35 package compiler.loopopts;
  36 
  37 public class TestOverunrolling {
  38 
  39     public static Object test(int arg) {
  40         Object arr[] = new Object[3];
  41         int lim = (arg & 3);
  42         // The pre loop is executed for one iteration, initializing p[0].
  43         // The main loop is unrolled twice, initializing p[1], p[2], p[3] and p[4].
  44         // The p[3] and p[4] stores are always out of bounds and removed. However,
  45         // C2 is unable to remove the "over-unrolled", dead main loop. As a result,
  46         // there is a control path from the main loop to the post loop without a
  47         // memory path (because the last store was replaced by TOP). We crash
  48         // because we use a memory edge from a non-dominating region.
  49         for (int i = 0; i < lim; ++i) {
  50             arr[i] = new Object();
  51         }
  52         // Avoid EA
  53         return arr;
  54     }
  55 
  56     public static void main(String args[]) {
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