commit cf3be7c4126c98247c235c5687443edd2a11eb2d
author Andrei Korzhevskii <a.korzhevskiy@gmail.com> Mon Jul 11 11:17:42 2016 +0300
committer Andrei Korzhevskii <a.korzhevskiy@gmail.com> Tue Jul 12 09:27:34 2016 +0000
tree 7e67bd2d9e0f192a2efbd17c9b8ec689a57c73af
parent d0794a98b98f936cb7b4a94151bc40a46206c2a3

Use InternalPreconditions.checkCriticalArithmetic in java.lang.Math

Change-Id: I08be0750a68cc1a195e835e015d5152a8abbbad9

user/super/com/google/gwt/emul/java/lang/Math.java

diff --git a/user/super/com/google/gwt/emul/java/lang/Math.java b/user/super/com/google/gwt/emul/java/lang/Math.java
index 922ef5d..26bf8f2 100644
--- a/user/super/com/google/gwt/emul/java/lang/Math.java
+++ b/user/super/com/google/gwt/emul/java/lang/Math.java
@@ -15,6 +15,8 @@
  */
 package java.lang;
 
+import static javaemul.internal.InternalPreconditions.checkCriticalArithmetic;
+
 import jsinterop.annotations.JsPackage;
 import jsinterop.annotations.JsType;
 
@@ -70,14 +72,14 @@
 
   public static int addExact(int x, int y) {
     double r = (double) x + (double) y;
-    throwOverflowIf(!isSafeIntegerRange(r));
+    checkCriticalArithmetic(isSafeIntegerRange(r));
     return (int) r;
   }
 
   public static long addExact(long x, long y) {
     long r = x + y;
     // "Hacker's Delight" 2-12 Overflow if both arguments have the opposite sign of the result
-    throwOverflowIf(((x ^ r) & (y ^ r)) < 0);
+    checkCriticalArithmetic(((x ^ r) & (y ^ r)) >= 0);
     return r;
   }
 
@@ -118,12 +120,12 @@
   }
 
   public static int decrementExact(int x) {
-    throwOverflowIf(x == Integer.MIN_VALUE);
+    checkCriticalArithmetic(x != Integer.MIN_VALUE);
     return x - 1;
   }
 
   public static long decrementExact(long x) {
-    throwOverflowIf(x == Long.MIN_VALUE);
+    checkCriticalArithmetic(x != Long.MIN_VALUE);
     return x - 1;
   }
 
@@ -140,24 +142,24 @@
   }
 
   public static int floorDiv(int dividend, int divisor) {
-    throwDivByZeroIf(divisor == 0);
+    checkCriticalArithmetic(divisor != 0);
     // round down division if the signs are different and modulo not zero
     return ((dividend ^ divisor) >= 0 ? dividend / divisor : ((dividend + 1) / divisor) - 1);
   }
 
   public static long floorDiv(long dividend, long divisor) {
-    throwDivByZeroIf(divisor == 0);
+    checkCriticalArithmetic(divisor != 0);
     // round down division if the signs are different and modulo not zero
     return ((dividend ^ divisor) >= 0 ? dividend / divisor : ((dividend + 1) / divisor) - 1);
   }
 
   public static int floorMod(int dividend, int divisor) {
-    throwDivByZeroIf(divisor == 0);
+    checkCriticalArithmetic(divisor != 0);
     return ((dividend % divisor) + divisor) % divisor;
   }
 
   public static long floorMod(long dividend, long divisor) {
-    throwDivByZeroIf(divisor == 0);
+    checkCriticalArithmetic(divisor != 0);
     return ((dividend % divisor) + divisor) % divisor;
   }
 
@@ -167,12 +169,12 @@
   }
 
   public static int incrementExact(int x) {
-    throwOverflowIf(x == Integer.MAX_VALUE);
+    checkCriticalArithmetic(x != Integer.MAX_VALUE);
     return x + 1;
   }
 
   public static long incrementExact(long x) {
-    throwOverflowIf(x == Long.MAX_VALUE);
+    checkCriticalArithmetic(x != Long.MAX_VALUE);
     return x + 1;
   }
 
@@ -222,7 +224,7 @@
 
   public static int multiplyExact(int x, int y) {
     double r = (double) x * (double) y;
-    throwOverflowIf(!isSafeIntegerRange(r));
+    checkCriticalArithmetic(isSafeIntegerRange(r));
     return (int) r;
   }
 
@@ -234,17 +236,17 @@
       return 0;
     }
     long r = x * y;
-    throwOverflowIf(r / y != x);
+    checkCriticalArithmetic(r / y == x);
     return r;
   }
 
   public static int negateExact(int x) {
-    throwOverflowIf(x == Integer.MIN_VALUE);
+    checkCriticalArithmetic(x != Integer.MIN_VALUE);
     return -x;
   }
 
   public static long negateExact(long x) {
-    throwOverflowIf(x == Long.MIN_VALUE);
+    checkCriticalArithmetic(x != Long.MIN_VALUE);
     return -x;
   }
 
@@ -281,7 +283,7 @@
 
   public static int subtractExact(int x, int y) {
     double r = (double) x - (double) y;
-    throwOverflowIf(!isSafeIntegerRange(r));
+    checkCriticalArithmetic(isSafeIntegerRange(r));
     return (int) r;
   }
 
@@ -289,7 +291,7 @@
     long r = x - y;
     // "Hacker's Delight" Overflow if the arguments have different signs and
     // the sign of the result is different than the sign of x
-    throwOverflowIf(((x ^ y) & (x ^ r)) < 0);
+    checkCriticalArithmetic(((x ^ y) & (x ^ r)) >= 0);
     return r;
   }
 
@@ -354,7 +356,7 @@
 
   public static int toIntExact(long x) {
     int ix = (int) x;
-    throwOverflowIf(ix != x);
+    checkCriticalArithmetic(ix == x);
     return ix;
   }
 
@@ -366,18 +368,6 @@
     return Integer.MIN_VALUE <= value && value <= Integer.MAX_VALUE;
   }
 
-  private static void throwDivByZeroIf(boolean condition) {
-    if (condition) {
-      throw new ArithmeticException("div by zero");
-    }
-  }
-
-  private static void throwOverflowIf(boolean condition) {
-    if (condition) {
-      throw new ArithmeticException("overflow");
-    }
-  }
-
   @JsType(isNative = true, name = "Math", namespace = JsPackage.GLOBAL)
   private static class NativeMath {
     public static double LOG10E;

user/test/com/google/gwt/emultest/java/lang/MathTest.java

diff --git a/user/test/com/google/gwt/emultest/java/lang/MathTest.java b/user/test/com/google/gwt/emultest/java/lang/MathTest.java
index 7557108..20897a4 100644
--- a/user/test/com/google/gwt/emultest/java/lang/MathTest.java
+++ b/user/test/com/google/gwt/emultest/java/lang/MathTest.java
@@ -501,7 +501,7 @@
   public void testSignum() {
     assertNaN(Math.signum(Double.NaN));
     assertNegativeZero(Math.signum(-0.0));
-    assertEquals(0.0, Math.signum(0.0));
+    assertPositiveZero(Math.signum(0.0));
     assertEquals(-1, Math.signum(-2));
     assertEquals(1, Math.signum(2));
     assertEquals(-1.0, Math.signum(-Double.MAX_VALUE));