blob: bfbc957beb2f5a03f688204cfc4a0342fa346f94 [file] [log] [blame]
/*
* Copyright (c) 2012, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* 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
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <gtest/gtest.h>
#include <limits.h>
#include "sky/engine/wtf/SaturatedArithmetic.h"
namespace {
TEST(SaturatedArithmeticTest, Addition)
{
EXPECT_EQ(0, saturatedAddition(0, 0));
EXPECT_EQ(1, saturatedAddition(0, 1));
EXPECT_EQ(100, saturatedAddition(0, 100));
EXPECT_EQ(150, saturatedAddition(100, 50));
EXPECT_EQ(-1, saturatedAddition(0, -1));
EXPECT_EQ(0, saturatedAddition(1, -1));
EXPECT_EQ(50, saturatedAddition(100, -50));
EXPECT_EQ(-50, saturatedAddition(50, -100));
EXPECT_EQ(INT_MAX - 1, saturatedAddition(INT_MAX - 1, 0));
EXPECT_EQ(INT_MAX, saturatedAddition(INT_MAX - 1, 1));
EXPECT_EQ(INT_MAX, saturatedAddition(INT_MAX - 1, 2));
EXPECT_EQ(INT_MAX - 1, saturatedAddition(0, INT_MAX - 1));
EXPECT_EQ(INT_MAX, saturatedAddition(1, INT_MAX - 1));
EXPECT_EQ(INT_MAX, saturatedAddition(2, INT_MAX - 1));
EXPECT_EQ(INT_MAX, saturatedAddition(INT_MAX - 1, INT_MAX - 1));
EXPECT_EQ(INT_MAX, saturatedAddition(INT_MAX, INT_MAX));
EXPECT_EQ(INT_MIN, saturatedAddition(INT_MIN, 0));
EXPECT_EQ(INT_MIN + 1, saturatedAddition(INT_MIN + 1, 0));
EXPECT_EQ(INT_MIN + 2, saturatedAddition(INT_MIN + 1, 1));
EXPECT_EQ(INT_MIN + 3, saturatedAddition(INT_MIN + 1, 2));
EXPECT_EQ(INT_MIN, saturatedAddition(INT_MIN + 1, -1));
EXPECT_EQ(INT_MIN, saturatedAddition(INT_MIN + 1, -2));
EXPECT_EQ(INT_MIN + 1, saturatedAddition(0, INT_MIN + 1));
EXPECT_EQ(INT_MIN, saturatedAddition(-1, INT_MIN + 1));
EXPECT_EQ(INT_MIN, saturatedAddition(-2, INT_MIN + 1));
EXPECT_EQ(INT_MAX / 2 + 10000, saturatedAddition(INT_MAX / 2, 10000));
EXPECT_EQ(INT_MAX, saturatedAddition(INT_MAX / 2 + 1, INT_MAX / 2 + 1));
EXPECT_EQ(-1, saturatedAddition(INT_MIN, INT_MAX));
}
TEST(SaturatedArithmeticTest, Subtraction)
{
EXPECT_EQ(0, saturatedSubtraction(0, 0));
EXPECT_EQ(-1, saturatedSubtraction(0, 1));
EXPECT_EQ(-100, saturatedSubtraction(0, 100));
EXPECT_EQ(50, saturatedSubtraction(100, 50));
EXPECT_EQ(1, saturatedSubtraction(0, -1));
EXPECT_EQ(2, saturatedSubtraction(1, -1));
EXPECT_EQ(150, saturatedSubtraction(100, -50));
EXPECT_EQ(150, saturatedSubtraction(50, -100));
EXPECT_EQ(INT_MAX, saturatedSubtraction(INT_MAX, 0));
EXPECT_EQ(INT_MAX - 1, saturatedSubtraction(INT_MAX, 1));
EXPECT_EQ(INT_MAX - 1, saturatedSubtraction(INT_MAX - 1, 0));
EXPECT_EQ(INT_MAX, saturatedSubtraction(INT_MAX - 1, -1));
EXPECT_EQ(INT_MAX, saturatedSubtraction(INT_MAX - 1, -2));
EXPECT_EQ(-INT_MAX + 1, saturatedSubtraction(0, INT_MAX - 1));
EXPECT_EQ(-INT_MAX, saturatedSubtraction(-1, INT_MAX - 1));
EXPECT_EQ(-INT_MAX - 1, saturatedSubtraction(-2, INT_MAX - 1));
EXPECT_EQ(-INT_MAX - 1, saturatedSubtraction(-3, INT_MAX - 1));
EXPECT_EQ(INT_MIN, saturatedSubtraction(INT_MIN, 0));
EXPECT_EQ(INT_MIN + 1, saturatedSubtraction(INT_MIN + 1, 0));
EXPECT_EQ(INT_MIN, saturatedSubtraction(INT_MIN + 1, 1));
EXPECT_EQ(INT_MIN, saturatedSubtraction(INT_MIN + 1, 2));
EXPECT_EQ(0, saturatedSubtraction(INT_MIN, INT_MIN));
EXPECT_EQ(0, saturatedSubtraction(INT_MAX, INT_MAX));
EXPECT_EQ(INT_MAX, saturatedSubtraction(INT_MAX, INT_MIN));
}
TEST(SaturatedArithmeticTest, SetSigned)
{
const int kFractionBits = 6;
const int intMaxForLayoutUnit = INT_MAX >> kFractionBits;
const int intMinForLayoutUnit = INT_MIN >> kFractionBits;
EXPECT_EQ(0, saturatedSet(0, kFractionBits));
// Internally the max number we can represent (without saturating)
// is all the (non-sign) bits set except for the bottom n fraction bits
const int maxInternalRepresentation = INT_MAX ^ ((1 << kFractionBits)-1);
EXPECT_EQ(maxInternalRepresentation,
saturatedSet(intMaxForLayoutUnit, kFractionBits));
EXPECT_EQ(getMaxSaturatedSetResultForTesting(kFractionBits),
saturatedSet(intMaxForLayoutUnit + 100, kFractionBits));
EXPECT_EQ((intMaxForLayoutUnit - 100) << kFractionBits,
saturatedSet(intMaxForLayoutUnit - 100, kFractionBits));
EXPECT_EQ(getMinSaturatedSetResultForTesting(kFractionBits),
saturatedSet(intMinForLayoutUnit, kFractionBits));
EXPECT_EQ(getMinSaturatedSetResultForTesting(kFractionBits),
saturatedSet(intMinForLayoutUnit - 100, kFractionBits));
EXPECT_EQ((intMinForLayoutUnit + 100) << kFractionBits,
saturatedSet(intMinForLayoutUnit + 100, kFractionBits));
}
TEST(SaturatedArithmeticTest, SetUnsigned)
{
const int kFractionBits = 6;
const int intMaxForLayoutUnit = INT_MAX >> kFractionBits;
EXPECT_EQ(0, saturatedSet((unsigned)0, kFractionBits));
EXPECT_EQ(getMaxSaturatedSetResultForTesting(kFractionBits),
saturatedSet((unsigned)intMaxForLayoutUnit, kFractionBits));
const unsigned kOverflowed = intMaxForLayoutUnit + 100;
EXPECT_EQ(getMaxSaturatedSetResultForTesting(kFractionBits),
saturatedSet(kOverflowed, kFractionBits));
const unsigned kNotOverflowed = intMaxForLayoutUnit - 100;
EXPECT_EQ((intMaxForLayoutUnit - 100) << kFractionBits,
saturatedSet(kNotOverflowed, kFractionBits));
}
} // namespace