diff options
Diffstat (limited to 'chromium/base/bits_unittest.cc')
| -rw-r--r-- | chromium/base/bits_unittest.cc | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/chromium/base/bits_unittest.cc b/chromium/base/bits_unittest.cc index 71becbe510b..249bbf7c457 100644 --- a/chromium/base/bits_unittest.cc +++ b/chromium/base/bits_unittest.cc @@ -202,5 +202,32 @@ TEST(BitsTest, PowerOfTwo) { EXPECT_FALSE(IsPowerOfTwo(int64_t{1} << 63)); } +TEST(BitsTest, LeftMostBit) { + // Construction of a signed type from an unsigned one of the same width + // preserves all bits. Explicitily confirming this behavior here to illustrate + // correctness of reusing unsigned literals to test behavior of signed types. + // Using signed literals does not work with EXPECT_EQ. + static_assert(int64_t(0xFFFFFFFFFFFFFFFFu) == 0xFFFFFFFFFFFFFFFFl, + "Comparing signed with unsigned literals compares bits."); + static_assert((0xFFFFFFFFFFFFFFFFu ^ 0xFFFFFFFFFFFFFFFFl) == 0, + "Signed and unsigned literals have the same bits set"); + + uint64_t unsigned_long_long_value = 0x8000000000000000u; + EXPECT_EQ(LeftmostBit<uint64_t>(), unsigned_long_long_value); + EXPECT_EQ(LeftmostBit<int64_t>(), int64_t(unsigned_long_long_value)); + + uint32_t unsigned_long_value = 0x80000000u; + EXPECT_EQ(LeftmostBit<uint32_t>(), unsigned_long_value); + EXPECT_EQ(LeftmostBit<int32_t>(), int32_t(unsigned_long_value)); + + uint16_t unsigned_short_value = 0x8000u; + EXPECT_EQ(LeftmostBit<uint16_t>(), unsigned_short_value); + EXPECT_EQ(LeftmostBit<int16_t>(), int16_t(unsigned_short_value)); + + uint8_t unsigned_byte_value = 0x80u; + EXPECT_EQ(LeftmostBit<uint8_t>(), unsigned_byte_value); + EXPECT_EQ(LeftmostBit<int8_t>(), int8_t(unsigned_byte_value)); +} + } // namespace bits } // namespace base |