1 /*
   2  * Copyright (c) 2013, 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 public class Verify {
  25   public static String throwWord(boolean threw) {
  26     return (threw ? "threw" : "didn't throw");
  27   }
  28 
  29   public static void verify(int a, int b) {
  30     boolean exception1 = false, exception2 = false;
  31     int result1 = 0, result2 = 0;
  32     try {
  33       result1 = testIntrinsic(a, b);
  34     } catch (ArithmeticException e) {
  35       exception1 = true;
  36     }
  37     try {
  38       result2 = testNonIntrinsic(a, b);
  39     } catch (ArithmeticException e) {
  40       exception2 = true;
  41     }
  42 
  43     if (exception1 != exception2) {
  44       throw new RuntimeException("Intrinsic version " + throwWord(exception1) + " exception, NonIntrinsic version " + throwWord(exception2) + " for: " + a + " + " + b);
  45     }
  46     if (result1 != result2) {
  47       throw new RuntimeException("Intrinsic version returned: " + a + " while NonIntrinsic version returned: " + b);
  48     }
  49   }
  50 
  51   public static int testIntrinsic(int a, int b) {
  52     return java.lang.Math.addExact(a, b);
  53   }
  54 
  55   public static int testNonIntrinsic(int a, int b) {
  56     return safeAddExact(a, b);
  57   }
  58 
  59   // Copied java.lang.Math.addExact to avoid intrinsification
  60   public static int safeAddExact(int x, int y) {
  61     int r = x + y;
  62     // HD 2-12 Overflow iff both arguments have the opposite sign of the result
  63     if (((x ^ r) & (y ^ r)) < 0) {
  64       throw new ArithmeticException("integer overflow");
  65     }
  66     return r;
  67   }
  68 }