/*
 * Copyright (c) 2012, Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 *
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 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 */

#include "config.h"

#include "wtf/SaturatedArithmetic.h"
#include <gtest/gtest.h>
#include <limits.h>

namespace {

TEST(WTF, SaturatedArithmeticAddition)
{
    ASSERT_EQ(saturatedAddition(0, 0), 0);
    ASSERT_EQ(saturatedAddition(0, 1), 1);
    ASSERT_EQ(saturatedAddition(0, 100), 100);
    ASSERT_EQ(saturatedAddition(100, 50), 150);

    ASSERT_EQ(saturatedAddition(0, -1), -1);
    ASSERT_EQ(saturatedAddition(1, -1), 0);
    ASSERT_EQ(saturatedAddition(100, -50), 50);
    ASSERT_EQ(saturatedAddition(50, -100), -50);

    ASSERT_EQ(saturatedAddition(INT_MAX - 1, 0), INT_MAX - 1);
    ASSERT_EQ(saturatedAddition(INT_MAX - 1, 1), INT_MAX);
    ASSERT_EQ(saturatedAddition(INT_MAX - 1, 2), INT_MAX);
    ASSERT_EQ(saturatedAddition(0, INT_MAX - 1), INT_MAX - 1);
    ASSERT_EQ(saturatedAddition(1, INT_MAX - 1), INT_MAX);
    ASSERT_EQ(saturatedAddition(2, INT_MAX - 1), INT_MAX);
    ASSERT_EQ(saturatedAddition(INT_MAX - 1, INT_MAX - 1), INT_MAX);
    ASSERT_EQ(saturatedAddition(INT_MAX, INT_MAX), INT_MAX);

    ASSERT_EQ(saturatedAddition(INT_MIN, 0), INT_MIN);
    ASSERT_EQ(saturatedAddition(INT_MIN + 1, 0), INT_MIN + 1);
    ASSERT_EQ(saturatedAddition(INT_MIN + 1, 1), INT_MIN + 2);
    ASSERT_EQ(saturatedAddition(INT_MIN + 1, 2), INT_MIN + 3);
    ASSERT_EQ(saturatedAddition(INT_MIN + 1, -1), INT_MIN);
    ASSERT_EQ(saturatedAddition(INT_MIN + 1, -2), INT_MIN);
    ASSERT_EQ(saturatedAddition(0, INT_MIN + 1), INT_MIN + 1);
    ASSERT_EQ(saturatedAddition(-1, INT_MIN + 1), INT_MIN);
    ASSERT_EQ(saturatedAddition(-2, INT_MIN + 1), INT_MIN);

    ASSERT_EQ(saturatedAddition(INT_MAX / 2, 10000), INT_MAX / 2 + 10000);
    ASSERT_EQ(saturatedAddition(INT_MAX / 2 + 1, INT_MAX / 2 + 1), INT_MAX);
    ASSERT_EQ(saturatedAddition(INT_MIN, INT_MAX), -1);
}

TEST(WTF, SaturatedArithmeticSubtraction)
{
    ASSERT_EQ(saturatedSubtraction(0, 0), 0);
    ASSERT_EQ(saturatedSubtraction(0, 1), -1);
    ASSERT_EQ(saturatedSubtraction(0, 100), -100);
    ASSERT_EQ(saturatedSubtraction(100, 50), 50);

    ASSERT_EQ(saturatedSubtraction(0, -1), 1);
    ASSERT_EQ(saturatedSubtraction(1, -1), 2);
    ASSERT_EQ(saturatedSubtraction(100, -50), 150);
    ASSERT_EQ(saturatedSubtraction(50, -100), 150);

    ASSERT_EQ(saturatedSubtraction(INT_MAX, 0), INT_MAX);
    ASSERT_EQ(saturatedSubtraction(INT_MAX, 1), INT_MAX - 1);
    ASSERT_EQ(saturatedSubtraction(INT_MAX - 1, 0), INT_MAX - 1);
    ASSERT_EQ(saturatedSubtraction(INT_MAX - 1, -1), INT_MAX);
    ASSERT_EQ(saturatedSubtraction(INT_MAX - 1, -2), INT_MAX);
    ASSERT_EQ(saturatedSubtraction(0, INT_MAX - 1), -INT_MAX + 1);
    ASSERT_EQ(saturatedSubtraction(-1, INT_MAX - 1), -INT_MAX);
    ASSERT_EQ(saturatedSubtraction(-2, INT_MAX - 1), -INT_MAX - 1);
    ASSERT_EQ(saturatedSubtraction(-3, INT_MAX - 1), -INT_MAX - 1);

    ASSERT_EQ(saturatedSubtraction(INT_MIN, 0), INT_MIN);
    ASSERT_EQ(saturatedSubtraction(INT_MIN + 1, 0), INT_MIN + 1);
    ASSERT_EQ(saturatedSubtraction(INT_MIN + 1, 1), INT_MIN);
    ASSERT_EQ(saturatedSubtraction(INT_MIN + 1, 2), INT_MIN);

    ASSERT_EQ(saturatedSubtraction(INT_MIN, INT_MIN), 0);
    ASSERT_EQ(saturatedSubtraction(INT_MAX, INT_MAX), 0);
    ASSERT_EQ(saturatedSubtraction(INT_MAX, INT_MIN), INT_MAX);
}

} // namespace