6282196: There should be Math.mod(number, modulo) methods

Summary: added the requested methods
Reviewed-by: darcy, emcmanus, alanb
Contributed-by: roger.riggs@oracle.com

src/share/classes/java/lang/Math.java

@@ -742,6 +742,7 @@ public final class Math {
      * @param y the second value
      * @return the result
      * @throws ArithmeticException if the result overflows an int
+     * @since 1.8
      */
     public static int addExact(int x, int y) {
         int r = x + y;
@@ -760,6 +761,7 @@ public final class Math {
      * @param y the second value
      * @return the result
      * @throws ArithmeticException if the result overflows a long
+     * @since 1.8
      */
     public static long addExact(long x, long y) {
         long r = x + y;
@@ -778,6 +780,7 @@ public final class Math {
      * @param y the second value to subtract from the first
      * @return the result
      * @throws ArithmeticException if the result overflows an int
+     * @since 1.8
      */
     public static int subtractExact(int x, int y) {
         int r = x - y;
@@ -797,6 +800,7 @@ public final class Math {
      * @param y the second value to subtract from the first
      * @return the result
      * @throws ArithmeticException if the result overflows a long
+     * @since 1.8
      */
     public static long subtractExact(long x, long y) {
         long r = x - y;
@@ -816,6 +820,7 @@ public final class Math {
      * @param y the second value
      * @return the result
      * @throws ArithmeticException if the result overflows an int
+     * @since 1.8
      */
     public static int multiplyExact(int x, int y) {
         long r = (long)x * (long)y;
@@ -833,6 +838,7 @@ public final class Math {
      * @param y the second value
      * @return the result
      * @throws ArithmeticException if the result overflows a long
+     * @since 1.8
      */
     public static long multiplyExact(long x, long y) {
         long r = x * y;
@@ -857,6 +863,7 @@ public final class Math {
      * @param value the long value
      * @return the argument as an int
      * @throws ArithmeticException if the {@code argument} overflows an int
+     * @since 1.8
      */
     public static int toIntExact(long value) {
         if ((int)value != value) {
@@ -865,6 +872,159 @@ public final class Math {
         return (int)value;
     }
 
+    /**
+     * Returns the largest (closest to positive infinity)
+     * {@code int} value that is less than or equal to the algebraic quotient.
+     * There is one special case, if the dividend is the
+     * {@linkplain Integer#MIN_VALUE Integer.MIN_VALUE} and the divisor is {@code -1},
+     * then integer overflow occurs and
+     * the result is equal to the {@code Integer.MIN_VALUE}.
+     * <p>
+     * Normal integer division operates under the round to zero rounding mode
+     * (truncation).  This operation instead acts under the round toward
+     * negative infinity (floor) rounding mode.
+     * The floor rounding mode gives different results than truncation
+     * when the exact result is negative.
+     * <ul>
+     *   <li>If the signs of the arguments are the same, the results of
+     *       {@code floorDiv} and the {@code /} operator are the same.  <br>
+     *       For example, {@code floorDiv(4, 3) == 1} and {@code (4 / 3) == 1}.</li>
+     *   <li>If the signs of the arguments are different,  the quotient is negative and
+     *       {@code floorDiv} returns the integer less than or equal to the quotient
+     *       and the {@code /} operator returns the integer closest to zero.<br>
+     *       For example, {@code floorDiv(-4, 3) == -2},
+     *       whereas {@code (-4 / 3) == -1}.
+     *   </li>
+     * </ul>
+     * <p>
+     *
+     * @param x the dividend
+     * @param y the divisor
+     * @return the largest (closest to positive infinity)
+     * {@code int} value that is less than or equal to the algebraic quotient.
+     * @throws ArithmeticException if the divisor {@code y} is zero
+     * @see #floorMod(int, int)
+     * @see #floor(double)
+     * @since 1.8
+     */
+    public static int floorDiv(int x, int y) {
+        int r = x / y;
+        // if the signs are different and modulo not zero, round down
+        if ((x ^ y) < 0 && (r * y != x)) {
+            r--;
+        }
+        return r;
+    }
+
+    /**
+     * Returns the largest (closest to positive infinity)
+     * {@code long} value that is less than or equal to the algebraic quotient.
+     * There is one special case, if the dividend is the
+     * {@linkplain Long#MIN_VALUE Long.MIN_VALUE} and the divisor is {@code -1},
+     * then integer overflow occurs and
+     * the result is equal to the {@code Long.MIN_VALUE}.
+     * <p>
+     * Normal integer division operates under the round to zero rounding mode
+     * (truncation).  This operation instead acts under the round toward
+     * negative infinity (floor) rounding mode.
+     * The floor rounding mode gives different results than truncation
+     * when the exact result is negative.
+     * <p>
+     * For examples, see {@link #floorDiv(int, int)}.
+     *
+     * @param x the dividend
+     * @param y the divisor
+     * @return the largest (closest to positive infinity)
+     * {@code long} value that is less than or equal to the algebraic quotient.
+     * @throws ArithmeticException if the divisor {@code y} is zero
+     * @see #floorMod(long, long)
+     * @see #floor(double)
+     * @since 1.8
+     */
+    public static long floorDiv(long x, long y) {
+        long r = x / y;
+        // if the signs are different and modulo not zero, round down
+        if ((x ^ y) < 0 && (r * y != x)) {
+            r--;
+        }
+        return r;
+    }
+
+    /**
+     * Returns the floor modulus of the {@code int} arguments.
+     * <p>
+     * The floor modulus is {@code x - (floorDiv(x, y) * y)},
+     * has the same sign as the divisor {@code y}, and
+     * is in the range of {@code -abs(y) < r < +abs(y)}.
+     *
+     * <p>
+     * The relationship between {@code floorDiv} and {@code floorMod} is such that:
+     * <ul>
+     *   <li>{@code floorDiv(x, y) * y + floorMod(x, y) == x}
+     * </ul>
+     * <p>
+     * The difference in values between {@code floorMod} and
+     * the {@code %} operator is due to the difference between
+     * {@code floorDiv} that returns the integer less than or equal to the quotient
+     * and the {@code /} operator that returns the integer closest to zero.
+     * <p>
+     * Examples:
+     * <ul>
+     *   <li>If the signs of the arguments are the same, the results
+     *       of {@code floorMod} and the {@code %} operator are the same.  <br>
+     *       <ul>
+     *       <li>{@code floorMod(4, 3) == 1}; &nbsp; and {@code (4 % 3) == 1}</li>
+     *       </ul>
+     *   <li>If the signs of the arguments are different, the results differ from the {@code %} operator.<br>
+     *      <ul>
+     *      <li>{@code floorMod(+4, -3) == -2}; &nbsp; and {@code (+4 % -3) == +1} </li>
+     *      <li>{@code floorMod(-4, +3) == +2}; &nbsp; and {@code (-4 % +3) == -1} </li>
+     *      <li>{@code floorMod(-4, -3) == -1}; &nbsp; and {@code (-4 % -3) == -1 } </li>
+     *      </ul>
+     *   </li>
+     * </ul>
+     * <p>
+     * If the signs of arguments are unknown and a positive modulus
+     * is needed it can be computed as {@code (floorMod(x, y) + abs(y)) % abs(y)}.
+     *
+     * @param x the dividend
+     * @param y the divisor
+     * @return the floor modulus {@code x - (floorDiv(x, y) * y)}
+     * @throws ArithmeticException if the divisor {@code y} is zero
+     * @see #floorDiv(int, int)
+     * @since 1.8
+     */
+    public static int floorMod(int x, int y) {
+        int r = x - floorDiv(x, y) * y;
+        return r;
+    }
+
+    /**
+     * Returns the floor modulus of the {@code long} arguments.
+     * <p>
+     * The floor modulus is {@code x - (floorDiv(x, y) * y)},
+     * has the same sign as the divisor {@code y}, and
+     * is in the range of {@code -abs(y) < r < +abs(y)}.
+     *
+     * <p>
+     * The relationship between {@code floorDiv} and {@code floorMod} is such that:
+     * <ul>
+     *   <li>{@code floorDiv(x, y) * y + floorMod(x, y) == x}
+     * </ul>
+     * <p>
+     * For examples, see {@link #floorMod(int, int)}.
+     *
+     * @param x the dividend
+     * @param y the divisor
+     * @return the floor modulus {@code x - (floorDiv(x, y) * y)}
+     * @throws ArithmeticException if the divisor {@code y} is zero
+     * @see #floorDiv(long, long)
+     * @since 1.8
+     */
+    public static long floorMod(long x, long y) {
+        return x - floorDiv(x, y) * y;
+    }
+
     /**
      * Returns the absolute value of an {@code int} value.
      * If the argument is not negative, the argument is returned.

src/share/classes/java/lang/StrictMath.java

@@ -365,7 +365,7 @@ public final class StrictMath {
      * @param a the value to be floored or ceiled
      * @param negativeBoundary result for values in (-1, 0)
      * @param positiveBoundary result for values in (0, 1)
-     * @param sign the sign of the result
+     * @param increment value to add when the argument is non-integral
      */
     private static double floorOrCeil(double a,
                                       double negativeBoundary,
@@ -702,7 +702,7 @@ public final class StrictMath {
      * <p>This method is properly synchronized to allow correct use by
      * more than one thread. However, if many threads need to generate
      * pseudorandom numbers at a great rate, it may reduce contention
-     * for each thread to have its own pseudorandom number generator.
+     * for each thread to have its own pseudorandom-number generator.
      *
      * @return  a pseudorandom {@code double} greater than or equal
      * to {@code 0.0} and less than {@code 1.0}.
@@ -745,7 +745,7 @@ public final class StrictMath {
     }
 
     /**
-     * Return the difference of the arguments,
+     * Returns the difference of the arguments,
      * throwing an exception if the result overflows an {@code int}.
      *
      * @param x the first value
@@ -760,7 +760,7 @@ public final class StrictMath {
     }
 
     /**
-     * Return the difference of the arguments,
+     * Returns the difference of the arguments,
      * throwing an exception if the result overflows a {@code long}.
      *
      * @param x the first value
@@ -775,7 +775,7 @@ public final class StrictMath {
     }
 
     /**
-     * Return the product of the arguments,
+     * Returns the product of the arguments,
      * throwing an exception if the result overflows an {@code int}.
      *
      * @param x the first value
@@ -790,7 +790,7 @@ public final class StrictMath {
     }
 
     /**
-     * Return the product of the arguments,
+     * Returns the product of the arguments,
      * throwing an exception if the result overflows a {@code long}.
      *
      * @param x the first value
@@ -805,7 +805,7 @@ public final class StrictMath {
     }
 
     /**
-     * Return the value of the {@code long} argument;
+     * Returns the value of the {@code long} argument;
      * throwing an exception if the value overflows an {@code int}.
      *
      * @param value the long value
@@ -818,6 +818,107 @@ public final class StrictMath {
         return Math.toIntExact(value);
     }
 
+    /**
+     * Returns the largest (closest to positive infinity)
+     * {@code int} value that is less than or equal to the algebraic quotient.
+     * There is one special case, if the dividend is the
+     * {@linkplain Integer#MIN_VALUE Integer.MIN_VALUE} and the divisor is {@code -1},
+     * then integer overflow occurs and
+     * the result is equal to the {@code Integer.MIN_VALUE}.
+     * <p>
+     * See {@link Math#floorDiv(int, int) Math.floorDiv} for examples and
+     * a comparison to the integer division {@code /} operator.
+     *
+     * @param x the dividend
+     * @param y the divisor
+     * @return the largest (closest to positive infinity)
+     * {@code int} value that is less than or equal to the algebraic quotient.
+     * @throws ArithmeticException if the divisor {@code y} is zero
+     * @see Math#floorDiv(int, int)
+     * @see Math#floor(double)
+     * @since 1.8
+     */
+    public static int floorDiv(int x, int y) {
+        return Math.floorDiv(x, y);
+    }
+
+    /**
+     * Returns the largest (closest to positive infinity)
+     * {@code long} value that is less than or equal to the algebraic quotient.
+     * There is one special case, if the dividend is the
+     * {@linkplain Long#MIN_VALUE Long.MIN_VALUE} and the divisor is {@code -1},
+     * then integer overflow occurs and
+     * the result is equal to the {@code Long.MIN_VALUE}.
+     * <p>
+     * See {@link Math#floorDiv(int, int) Math.floorDiv} for examples and
+     * a comparison to the integer division {@code /} operator.
+     *
+     * @param x the dividend
+     * @param y the divisor
+     * @return the largest (closest to positive infinity)
+     * {@code long} value that is less than or equal to the algebraic quotient.
+     * @throws ArithmeticException if the divisor {@code y} is zero
+     * @see Math#floorDiv(long, long)
+     * @see Math#floor(double)
+     * @since 1.8
+     */
+    public static long floorDiv(long x, long y) {
+        return Math.floorDiv(x, y);
+    }
+
+    /**
+     * Returns the floor modulus of the {@code int} arguments.
+     * <p>
+     * The floor modulus is {@code x - (floorDiv(x, y) * y)},
+     * has the same sign as the divisor {@code y}, and
+     * is in the range of {@code -abs(y) < r < +abs(y)}.
+     * <p>
+     * The relationship between {@code floorDiv} and {@code floorMod} is such that:
+     * <ul>
+     *   <li>{@code floorDiv(x, y) * y + floorMod(x, y) == x}
+     * </ul>
+     * <p>
+     * See {@link Math#floorMod(int, int) Math.floorMod} for examples and
+     * a comparison to the {@code %} operator.
+     *
+     * @param x the dividend
+     * @param y the divisor
+     * @return the floor modulus {@code x - (floorDiv(x, y) * y)}
+     * @throws ArithmeticException if the divisor {@code y} is zero
+     * @see Math#floorMod(int, int)
+     * @see StrictMath#floorDiv(int, int)
+     * @since 1.8
+     */
+    public static int floorMod(int x, int y) {
+        return Math.floorMod(x , y);
+    }
+    /**
+     * Returns the floor modulus of the {@code long} arguments.
+     * <p>
+     * The floor modulus is {@code x - (floorDiv(x, y) * y)},
+     * has the same sign as the divisor {@code y}, and
+     * is in the range of {@code -abs(y) < r < +abs(y)}.
+     * <p>
+     * The relationship between {@code floorDiv} and {@code floorMod} is such that:
+     * <ul>
+     *   <li>{@code floorDiv(x, y) * y + floorMod(x, y) == x}
+     * </ul>
+     * <p>
+     * See {@link Math#floorMod(int, int) Math.floorMod} for examples and
+     * a comparison to the {@code %} operator.
+     *
+     * @param x the dividend
+     * @param y the divisor
+     * @return the floor modulus {@code x - (floorDiv(x, y) * y)}
+     * @throws ArithmeticException if the divisor {@code y} is zero
+     * @see Math#floorMod(long, long)
+     * @see StrictMath#floorDiv(long, long)
+     * @since 1.8
+     */
+    public static long floorMod(long x, long y) {
+        return Math.floorMod(x, y);
+    }
+
     /**
      * Returns the absolute value of an {@code int} value.
      * If the argument is not negative, the argument is returned.
@@ -1543,7 +1644,7 @@ public final class StrictMath {
     }
 
     /**
-     * Return {@code d} &times;
+     * Returns {@code d} &times;
      * 2<sup>{@code scaleFactor}</sup> rounded as if performed
      * by a single correctly rounded floating-point multiply to a
      * member of the double value set.  See the Java
@@ -1577,7 +1678,7 @@ public final class StrictMath {
     }
 
     /**
-     * Return {@code f} &times;
+     * Returns {@code f} &times;
      * 2<sup>{@code scaleFactor}</sup> rounded as if performed
      * by a single correctly rounded floating-point multiply to a
      * member of the float value set.  See the Java

test/java/lang/Math/DivModTests.java

+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+
+/**
+ * @test Test Math and StrictMath Floor Div / Modulo operations.
+ * @bug 6282196
+ * @summary Basic tests for Floor division and modulo methods for both Math
+ * and StrictMath for int and long datatypes.
+ */
+public class DivModTests {
+
+    /**
+     * The count of test errors.
+     */
+    private static int errors = 0;
+
+    /**
+     * @param args the command line arguments are unused
+     */
+    public static void main(String[] args) {
+        errors = 0;
+        testIntFloorDivMod();
+        testLongFloorDivMod();
+
+        if (errors > 0) {
+            throw new RuntimeException(errors + " errors found in DivMod methods.");
+        }
+    }
+
+    /**
+     * Report a test failure and increment the error count.
+     * @param message the formatting string
+     * @param args the variable number of arguments for the message.
+     */
+    static void fail(String message, Object... args) {
+        errors++;
+        System.out.printf(message, args);
+    }
+
+    /**
+     * Test the integer floorDiv and floorMod methods.
+     * Math and StrictMath tested and the same results are expected for both.
+     */
+    static void testIntFloorDivMod() {
+        testIntFloorDivMod(4, 0, new ArithmeticException("/ by zero"), new ArithmeticException("/ by zero")); // Should throw ArithmeticException
+        testIntFloorDivMod(4, 3, 1, 1);
+        testIntFloorDivMod(3, 3, 1, 0);
+        testIntFloorDivMod(2, 3, 0, 2);
+        testIntFloorDivMod(1, 3, 0, 1);
+        testIntFloorDivMod(0, 3, 0, 0);
+        testIntFloorDivMod(4, -3, -2, -2);
+        testIntFloorDivMod(3, -3, -1, 0);
+        testIntFloorDivMod(2, -3, -1, -1);
+        testIntFloorDivMod(1, -3, -1, -2);
+        testIntFloorDivMod(0, -3, 0, 0);
+        testIntFloorDivMod(-1, 3, -1, 2);
+        testIntFloorDivMod(-2, 3, -1, 1);
+        testIntFloorDivMod(-3, 3, -1, 0);
+        testIntFloorDivMod(-4, 3, -2, 2);
+        testIntFloorDivMod(-1, -3, 0, -1);
+        testIntFloorDivMod(-2, -3, 0, -2);
+        testIntFloorDivMod(-3, -3, 1, 0);
+        testIntFloorDivMod(-4, -3, 1, -1);
+        testIntFloorDivMod(Integer.MAX_VALUE, 1, Integer.MAX_VALUE, 0);
+        testIntFloorDivMod(Integer.MAX_VALUE, -1, -Integer.MAX_VALUE, 0);
+        testIntFloorDivMod(Integer.MAX_VALUE, 3, 715827882, 1);
+        testIntFloorDivMod(Integer.MAX_VALUE - 1, 3, 715827882, 0);
+        testIntFloorDivMod(Integer.MIN_VALUE, 3, -715827883, 1);
+        testIntFloorDivMod(Integer.MIN_VALUE + 1, 3, -715827883, 2);
+        testIntFloorDivMod(Integer.MIN_VALUE + 1, -1, Integer.MAX_VALUE, 0);
+        // Special case of integer overflow
+        testIntFloorDivMod(Integer.MIN_VALUE, -1, Integer.MIN_VALUE, 0);
+    }
+
+    /**
+     * Test FloorDiv and then FloorMod with int data.
+     */
+    static void testIntFloorDivMod(int x, int y, Object divExpected, Object modExpected) {
+        testIntFloorDiv(x, y, divExpected);
+        testIntFloorMod(x, y, modExpected);
+    }
+
+    /**
+     * Test FloorDiv with int data.
+     */
+    static void testIntFloorDiv(int x, int y, Object expected) {
+        Object result = doFloorDiv(x, y);
+        if (!resultEquals(result, expected)) {
+            fail("FAIL: Math.floorDiv(%d, %d) = %s; expected %s%n", x, y, result, expected);
+        }
+
+        Object strict_result = doStrictFloorDiv(x, y);
+        if (!resultEquals(strict_result, expected)) {
+            fail("FAIL: StrictMath.floorDiv(%d, %d) = %s; expected %s%n", x, y, strict_result, expected);
+        }
+    }
+
+    /**
+     * Test FloorMod with int data.
+     */
+    static void testIntFloorMod(int x, int y, Object expected) {
+        Object result = doFloorMod(x, y);
+        if (!resultEquals(result, expected)) {
+            fail("FAIL: Math.floorMod(%d, %d) = %s; expected %s%n", x, y, result, expected);
+        }
+
+        Object strict_result = doStrictFloorMod(x, y);
+        if (!resultEquals(strict_result, expected)) {
+            fail("FAIL: StrictMath.floorMod(%d, %d) = %s; expected %s%n", x, y, strict_result, expected);
+        }
+
+        try {
+            // Verify result against double precision floor function
+            int tmp = x / y;     // Force ArithmeticException for divide by zero
+            double ff = x - Math.floor((double)x / (double)y) * y;
+            int fr = (int)ff;
+            if (fr != result) {
+                fail("FAIL: Math.floorMod(%d, %d) = %s differs from Math.floor(x, y): %d%n", x, y, result, fr);
+            }
+        } catch (ArithmeticException ae) {
+            if (y != 0) {
+                fail("FAIL: Math.floorMod(%d, %d); unexpected %s%n", x, y, ae);
+            }
+        }
+    }
+
+    /**
+     * Test the floorDiv and floorMod methods for primitive long.
+     */
+    static void testLongFloorDivMod() {
+        testLongFloorDivMod(4L, 0L, new ArithmeticException("/ by zero"), new ArithmeticException("/ by zero")); // Should throw ArithmeticException
+        testLongFloorDivMod(4L, 3L, 1L, 1L);
+        testLongFloorDivMod(3L, 3L, 1L, 0L);
+        testLongFloorDivMod(2L, 3L, 0L, 2L);
+        testLongFloorDivMod(1L, 3L, 0L, 1L);
+        testLongFloorDivMod(0L, 3L, 0L, 0L);
+        testLongFloorDivMod(4L, -3L, -2L, -2L);
+        testLongFloorDivMod(3L, -3L, -1L, 0l);
+        testLongFloorDivMod(2L, -3L, -1L, -1L);
+        testLongFloorDivMod(1L, -3L, -1L, -2L);
+        testLongFloorDivMod(0L, -3L, 0L, 0L);
+        testLongFloorDivMod(-1L, 3L, -1L, 2L);
+        testLongFloorDivMod(-2L, 3L, -1L, 1L);
+        testLongFloorDivMod(-3L, 3L, -1L, 0L);
+        testLongFloorDivMod(-4L, 3L, -2L, 2L);
+        testLongFloorDivMod(-1L, -3L, 0L, -1L);
+        testLongFloorDivMod(-2L, -3L, 0L, -2L);
+        testLongFloorDivMod(-3L, -3L, 1L, 0L);
+        testLongFloorDivMod(-4L, -3L, 1L, -1L);
+
+        testLongFloorDivMod(Long.MAX_VALUE, 1, Long.MAX_VALUE, 0L);
+        testLongFloorDivMod(Long.MAX_VALUE, -1, -Long.MAX_VALUE, 0L);
+        testLongFloorDivMod(Long.MAX_VALUE, 3L, Long.MAX_VALUE / 3L, 1L);
+        testLongFloorDivMod(Long.MAX_VALUE - 1L, 3L, (Long.MAX_VALUE - 1L) / 3L, 0L);
+        testLongFloorDivMod(Long.MIN_VALUE, 3L, Long.MIN_VALUE / 3L - 1L, 1L);
+        testLongFloorDivMod(Long.MIN_VALUE + 1L, 3L, Long.MIN_VALUE / 3L - 1L, 2L);
+        testLongFloorDivMod(Long.MIN_VALUE + 1, -1, Long.MAX_VALUE, 0L);
+        // Special case of integer overflow
+        testLongFloorDivMod(Long.MIN_VALUE, -1, Long.MIN_VALUE, 0L);
+    }
+
+    /**
+     * Test the integer floorDiv and floorMod methods.
+     * Math and StrictMath are tested and the same results are expected for both.
+     */
+    static void testLongFloorDivMod(long x, long y, Object divExpected, Object modExpected) {
+        testLongFloorDiv(x, y, divExpected);
+        testLongFloorMod(x, y, modExpected);
+    }
+
+    /**
+     * Test FloorDiv with long arguments against expected value.
+     * The expected value is usually a Long but in some cases  is
+     * an ArithmeticException.
+     *
+     * @param x dividend
+     * @param y modulus
+     * @param expected expected value,
+     */
+    static void testLongFloorDiv(long x, long y, Object expected) {
+        Object result = doFloorDiv(x, y);
+        if (!resultEquals(result, expected)) {
+            fail("FAIL: long Math.floorDiv(%d, %d) = %s; expected %s%n", x, y, result, expected);
+        }
+
+        Object strict_result = doStrictFloorDiv(x, y);
+        if (!resultEquals(strict_result, expected)) {
+            fail("FAIL: long StrictMath.floorDiv(%d, %d) = %s; expected %s%n", x, y, strict_result, expected);
+        }
+    }
+
+    /**
+     * Test FloorMod of long arguments against expected value.
+     * The expected value is usually a Long but in some cases  is
+     * an ArithmeticException.
+     *
+     * @param x dividend
+     * @param y modulus
+     * @param expected expected value
+     */
+    static void testLongFloorMod(long x, long y, Object expected) {
+        Object result = doFloorMod(x, y);
+        if (!resultEquals(result, expected)) {
+            fail("FAIL: long Math.floorMod(%d, %d) = %s; expected %s%n", x, y, result, expected);
+        }
+
+        Object strict_result = doStrictFloorMod(x, y);
+        if (!resultEquals(strict_result, expected)) {
+            fail("FAIL: long StrictMath.floorMod(%d, %d) = %s; expected %s%n", x, y, strict_result, expected);
+        }
+
+        try {
+            // Verify the result against BigDecimal rounding mode.
+            BigDecimal xD = new BigDecimal(x);
+            BigDecimal yD = new BigDecimal(y);
+            BigDecimal resultD = xD.divide(yD, RoundingMode.FLOOR);
+            resultD = resultD.multiply(yD);
+            resultD = xD.subtract(resultD);
+            long fr = resultD.longValue();
+            if (fr != result) {
+                fail("FAIL: Long.floorMod(%d, %d) = %d is different than BigDecimal result: %d%n",x, y, result, fr);
+
+            }
+        } catch (ArithmeticException ae) {
+            if (y != 0) {
+                fail("FAIL: long Math.floorMod(%d, %d); unexpected ArithmeticException from bigdecimal");
+            }
+        }
+    }
+
+    /**
+     * Invoke floorDiv and return the result or any exception.
+     * @param x the x value
+     * @param y the y value
+     * @return the result Integer or an exception.
+     */
+    static Object doFloorDiv(int x, int y) {
+        try {
+            return Math.floorDiv(x, y);
+        } catch (ArithmeticException ae) {
+            return ae;
+        }
+    }
+
+    /**
+     * Invoke floorDiv and return the result or any exception.
+     * @param x the x value
+     * @param y the y value
+     * @return the result Integer or an exception.
+     */
+    static Object doFloorDiv(long x, long y) {
+        try {
+            return Math.floorDiv(x, y);
+        } catch (ArithmeticException ae) {
+            return ae;
+        }
+    }
+
+    /**
+     * Invoke floorDiv and return the result or any exception.
+     * @param x the x value
+     * @param y the y value
+     * @return the result Integer or an exception.
+     */
+    static Object doFloorMod(int x, int y) {
+        try {
+            return Math.floorMod(x, y);
+        } catch (ArithmeticException ae) {
+            return ae;
+        }
+    }
+
+    /**
+     * Invoke floorDiv and return the result or any exception.
+     * @param x the x value
+     * @param y the y value
+     * @return the result Integer or an exception.
+     */
+    static Object doFloorMod(long x, long y) {
+        try {
+            return Math.floorMod(x, y);
+        } catch (ArithmeticException ae) {
+            return ae;
+        }
+    }
+
+    /**
+     * Invoke floorDiv and return the result or any exception.
+     * @param x the x value
+     * @param y the y value
+     * @return the result Integer or an exception.
+     */
+    static Object doStrictFloorDiv(int x, int y) {
+        try {
+            return StrictMath.floorDiv(x, y);
+        } catch (ArithmeticException ae) {
+            return ae;
+        }
+    }
+
+    /**
+     * Invoke floorDiv and return the result or any exception.
+     * @param x the x value
+     * @param y the y value
+     * @return the result Integer or an exception.
+     */
+    static Object doStrictFloorDiv(long x, long y) {
+        try {
+            return StrictMath.floorDiv(x, y);
+        } catch (ArithmeticException ae) {
+            return ae;
+        }
+    }
+
+    /**
+     * Invoke floorDiv and return the result or any exception.
+     * @param x the x value
+     * @param y the y value
+     * @return the result Integer or an exception.
+     */
+    static Object doStrictFloorMod(int x, int y) {
+        try {
+            return StrictMath.floorMod(x, y);
+        } catch (ArithmeticException ae) {
+            return ae;
+        }
+    }
+
+    /**
+     * Invoke floorDiv and return the result or any exception.
+     * @param x the x value
+     * @param y the y value
+     * @return the result Integer or an exception.
+     */
+    static Object doStrictFloorMod(long x, long y) {
+        try {
+            return StrictMath.floorMod(x, y);
+        } catch (ArithmeticException ae) {
+            return ae;
+        }
+    }
+
+    /**
+     * Returns a boolean by comparing the result and the expected value.
+     * The equals method is not defined for ArithmeticException but it is
+     * desirable to have equals return true if the expected and the result
+     * both threw the same exception (class and message.)
+     *
+     * @param result the result from testing the method
+     * @param expected the expected value
+     * @return true if the result is equal to the expected values; false otherwise.
+     */
+    static boolean resultEquals(Object result, Object expected) {
+        if (result.getClass() != expected.getClass()) {
+            fail("FAIL: Result type mismatch, %s; expected: %s%n",
+                    result.getClass().getName(), expected.getClass().getName());
+            return false;
+        }
+
+        if (result.equals(expected)) {
+            return true;
+        }
+        // Handle special case to compare ArithmeticExceptions
+        if (result instanceof ArithmeticException && expected instanceof ArithmeticException) {
+            ArithmeticException ae1 = (ArithmeticException)result;
+            ArithmeticException ae2 = (ArithmeticException)expected;
+            return ae1.getMessage().equals(ae2.getMessage());
+        }
+        return false;
+    }
+
+}