namespace {
+TEST(MathExtras, countTrailingZeros) {
+ uint8_t Z8 = 0;
+ uint16_t Z16 = 0;
+ uint32_t Z32 = 0;
+ uint64_t Z64 = 0;
+ EXPECT_EQ(8u, countTrailingZeros(Z8));
+ EXPECT_EQ(16u, countTrailingZeros(Z16));
+ EXPECT_EQ(32u, countTrailingZeros(Z32));
+ EXPECT_EQ(64u, countTrailingZeros(Z64));
+
+ uint8_t NZ8 = 42;
+ uint16_t NZ16 = 42;
+ uint32_t NZ32 = 42;
+ uint64_t NZ64 = 42;
+ EXPECT_EQ(1u, countTrailingZeros(NZ8));
+ EXPECT_EQ(1u, countTrailingZeros(NZ16));
+ EXPECT_EQ(1u, countTrailingZeros(NZ32));
+ EXPECT_EQ(1u, countTrailingZeros(NZ64));
+}
+
+TEST(MathExtras, countLeadingZeros) {
+ uint8_t Z8 = 0;
+ uint16_t Z16 = 0;
+ uint32_t Z32 = 0;
+ uint64_t Z64 = 0;
+ EXPECT_EQ(8u, countLeadingZeros(Z8));
+ EXPECT_EQ(16u, countLeadingZeros(Z16));
+ EXPECT_EQ(32u, countLeadingZeros(Z32));
+ EXPECT_EQ(64u, countLeadingZeros(Z64));
+
+ uint8_t NZ8 = 42;
+ uint16_t NZ16 = 42;
+ uint32_t NZ32 = 42;
+ uint64_t NZ64 = 42;
+ EXPECT_EQ(2u, countLeadingZeros(NZ8));
+ EXPECT_EQ(10u, countLeadingZeros(NZ16));
+ EXPECT_EQ(26u, countLeadingZeros(NZ32));
+ EXPECT_EQ(58u, countLeadingZeros(NZ64));
+
+ EXPECT_EQ(8u, countLeadingZeros(0x00F000FFu));
+ EXPECT_EQ(8u, countLeadingZeros(0x00F12345u));
+ for (unsigned i = 0; i <= 30; ++i) {
+ EXPECT_EQ(31 - i, countLeadingZeros(1u << i));
+ }
+
+ EXPECT_EQ(8u, countLeadingZeros(0x00F1234500F12345ULL));
+ EXPECT_EQ(1u, countLeadingZeros(1ULL << 62));
+ for (unsigned i = 0; i <= 62; ++i) {
+ EXPECT_EQ(63 - i, countLeadingZeros(1ULL << i));
+ }
+}
+
+TEST(MathExtras, findFirstSet) {
+ uint8_t Z8 = 0;
+ uint16_t Z16 = 0;
+ uint32_t Z32 = 0;
+ uint64_t Z64 = 0;
+ EXPECT_EQ(0xFFULL, findFirstSet(Z8));
+ EXPECT_EQ(0xFFFFULL, findFirstSet(Z16));
+ EXPECT_EQ(0xFFFFFFFFULL, findFirstSet(Z32));
+ EXPECT_EQ(0xFFFFFFFFFFFFFFFFULL, findFirstSet(Z64));
+
+ uint8_t NZ8 = 42;
+ uint16_t NZ16 = 42;
+ uint32_t NZ32 = 42;
+ uint64_t NZ64 = 42;
+ EXPECT_EQ(1u, findFirstSet(NZ8));
+ EXPECT_EQ(1u, findFirstSet(NZ16));
+ EXPECT_EQ(1u, findFirstSet(NZ32));
+ EXPECT_EQ(1u, findFirstSet(NZ64));
+}
+
+TEST(MathExtras, findLastSet) {
+ uint8_t Z8 = 0;
+ uint16_t Z16 = 0;
+ uint32_t Z32 = 0;
+ uint64_t Z64 = 0;
+ EXPECT_EQ(0xFFULL, findLastSet(Z8));
+ EXPECT_EQ(0xFFFFULL, findLastSet(Z16));
+ EXPECT_EQ(0xFFFFFFFFULL, findLastSet(Z32));
+ EXPECT_EQ(0xFFFFFFFFFFFFFFFFULL, findLastSet(Z64));
+
+ uint8_t NZ8 = 42;
+ uint16_t NZ16 = 42;
+ uint32_t NZ32 = 42;
+ uint64_t NZ64 = 42;
+ EXPECT_EQ(5u, findLastSet(NZ8));
+ EXPECT_EQ(5u, findLastSet(NZ16));
+ EXPECT_EQ(5u, findLastSet(NZ32));
+ EXPECT_EQ(5u, findLastSet(NZ64));
+}
+
+TEST(MathExtras, reverseBits) {
+ uint8_t NZ8 = 42;
+ uint16_t NZ16 = 42;
+ uint32_t NZ32 = 42;
+ uint64_t NZ64 = 42;
+ EXPECT_EQ(0x54ULL, reverseBits(NZ8));
+ EXPECT_EQ(0x5400ULL, reverseBits(NZ16));
+ EXPECT_EQ(0x54000000ULL, reverseBits(NZ32));
+ EXPECT_EQ(0x5400000000000000ULL, reverseBits(NZ64));
+}
+
TEST(MathExtras, isPowerOf2_32) {
EXPECT_TRUE(isPowerOf2_32(1 << 6));
EXPECT_TRUE(isPowerOf2_32(1 << 12));
EXPECT_EQ(0x1100FFEEDDCCBBAAULL, ByteSwap_64(0xAABBCCDDEEFF0011LL));
}
-TEST(MathExtras, CountLeadingZeros_32) {
- EXPECT_EQ(8u, CountLeadingZeros_32(0x00F000FF));
- EXPECT_EQ(8u, CountLeadingZeros_32(0x00F12345));
- for (unsigned i = 0; i <= 30; ++i) {
- EXPECT_EQ(31 - i, CountLeadingZeros_32(1 << i));
- }
-}
-
-TEST(MathExtras, CountLeadingZeros_64) {
- EXPECT_EQ(8u, CountLeadingZeros_64(0x00F1234500F12345LL));
- EXPECT_EQ(1u, CountLeadingZeros_64(1LL << 62));
- for (unsigned i = 0; i <= 62; ++i) {
- EXPECT_EQ(63 - i, CountLeadingZeros_64(1LL << i));
- }
-}
-
-TEST(MathExtras, CountLeadingOnes_32) {
+TEST(MathExtras, countLeadingOnes) {
for (int i = 30; i >= 0; --i) {
// Start with all ones and unset some bit.
- EXPECT_EQ(31u - i, CountLeadingOnes_32(0xFFFFFFFF ^ (1 << i)));
+ EXPECT_EQ(31u - i, countLeadingOnes(0xFFFFFFFF ^ (1 << i)));
}
-}
-
-TEST(MathExtras, CountLeadingOnes_64) {
for (int i = 62; i >= 0; --i) {
// Start with all ones and unset some bit.
- EXPECT_EQ(63u - i, CountLeadingOnes_64(0xFFFFFFFFFFFFFFFFLL ^ (1LL << i)));
+ EXPECT_EQ(63u - i, countLeadingOnes(0xFFFFFFFFFFFFFFFFULL ^ (1LL << i)));
}
for (int i = 30; i >= 0; --i) {
// Start with all ones and unset some bit.
- EXPECT_EQ(31u - i, CountLeadingOnes_32(0xFFFFFFFF ^ (1 << i)));
+ EXPECT_EQ(31u - i, countLeadingOnes(0xFFFFFFFF ^ (1 << i)));
}
}
TEST(MathExtras, FloatBits) {
- static const float kValue = 5632.34;
+ static const float kValue = 5632.34f;
EXPECT_FLOAT_EQ(kValue, BitsToFloat(FloatToBits(kValue)));
}
EXPECT_EQ(8u, RoundUpToAlignment(5, 8));
EXPECT_EQ(24u, RoundUpToAlignment(17, 8));
EXPECT_EQ(0u, RoundUpToAlignment(~0LL, 8));
+
+ EXPECT_EQ(7u, RoundUpToAlignment(5, 8, 7));
+ EXPECT_EQ(17u, RoundUpToAlignment(17, 8, 1));
+ EXPECT_EQ(3u, RoundUpToAlignment(~0LL, 8, 3));
+ EXPECT_EQ(552u, RoundUpToAlignment(321, 255, 42));
+}
+
+template<typename T>
+void SaturatingAddTestHelper()
+{
+ const T Max = std::numeric_limits<T>::max();
+ bool ResultOverflowed;
+
+ EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2)));
+ EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2), &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+
+ EXPECT_EQ(Max, SaturatingAdd(Max, T(1)));
+ EXPECT_EQ(Max, SaturatingAdd(Max, T(1), &ResultOverflowed));
+ EXPECT_TRUE(ResultOverflowed);
+
+ EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1)));
+ EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1), &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+
+ EXPECT_EQ(Max, SaturatingAdd(T(1), Max));
+ EXPECT_EQ(Max, SaturatingAdd(T(1), Max, &ResultOverflowed));
+ EXPECT_TRUE(ResultOverflowed);
+
+ EXPECT_EQ(Max, SaturatingAdd(Max, Max));
+ EXPECT_EQ(Max, SaturatingAdd(Max, Max, &ResultOverflowed));
+ EXPECT_TRUE(ResultOverflowed);
+}
+
+TEST(MathExtras, SaturatingAdd) {
+ SaturatingAddTestHelper<uint8_t>();
+ SaturatingAddTestHelper<uint16_t>();
+ SaturatingAddTestHelper<uint32_t>();
+ SaturatingAddTestHelper<uint64_t>();
+}
+
+template<typename T>
+void SaturatingMultiplyTestHelper()
+{
+ const T Max = std::numeric_limits<T>::max();
+ bool ResultOverflowed;
+
+ // Test basic multiplication.
+ EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3)));
+ EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3), &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+
+ EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2)));
+ EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2), &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+
+ // Test multiplication by zero.
+ EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0)));
+ EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0), &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+
+ EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0)));
+ EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0), &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+
+ EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1)));
+ EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1), &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+
+ EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0)));
+ EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0), &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+
+ EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max));
+ EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max, &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+
+ // Test multiplication by maximum value.
+ EXPECT_EQ(Max, SaturatingMultiply(Max, T(2)));
+ EXPECT_EQ(Max, SaturatingMultiply(Max, T(2), &ResultOverflowed));
+ EXPECT_TRUE(ResultOverflowed);
+
+ EXPECT_EQ(Max, SaturatingMultiply(T(2), Max));
+ EXPECT_EQ(Max, SaturatingMultiply(T(2), Max, &ResultOverflowed));
+ EXPECT_TRUE(ResultOverflowed);
+
+ EXPECT_EQ(Max, SaturatingMultiply(Max, Max));
+ EXPECT_EQ(Max, SaturatingMultiply(Max, Max, &ResultOverflowed));
+ EXPECT_TRUE(ResultOverflowed);
+
+ // Test interesting boundary conditions for algorithm -
+ // ((1 << A) - 1) * ((1 << B) + K) for K in [-1, 0, 1]
+ // and A + B == std::numeric_limits<T>::digits.
+ // We expect overflow iff A > B and K = 1.
+ const int Digits = std::numeric_limits<T>::digits;
+ for (int A = 1, B = Digits - 1; B >= 1; ++A, --B) {
+ for (int K = -1; K <= 1; ++K) {
+ T X = (T(1) << A) - T(1);
+ T Y = (T(1) << B) + K;
+ bool OverflowExpected = A > B && K == 1;
+
+ if(OverflowExpected) {
+ EXPECT_EQ(Max, SaturatingMultiply(X, Y));
+ EXPECT_EQ(Max, SaturatingMultiply(X, Y, &ResultOverflowed));
+ EXPECT_TRUE(ResultOverflowed);
+ } else {
+ EXPECT_EQ(X * Y, SaturatingMultiply(X, Y));
+ EXPECT_EQ(X * Y, SaturatingMultiply(X, Y, &ResultOverflowed));
+ EXPECT_FALSE(ResultOverflowed);
+ }
+ }
+ }
+}
+
+TEST(MathExtras, SaturatingMultiply) {
+ SaturatingMultiplyTestHelper<uint8_t>();
+ SaturatingMultiplyTestHelper<uint16_t>();
+ SaturatingMultiplyTestHelper<uint32_t>();
+ SaturatingMultiplyTestHelper<uint64_t>();
}
}