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Diffstat (limited to 'absl/base/bit_cast_test.cc')
-rw-r--r-- | absl/base/bit_cast_test.cc | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/absl/base/bit_cast_test.cc b/absl/base/bit_cast_test.cc new file mode 100644 index 00000000..8cd878d7 --- /dev/null +++ b/absl/base/bit_cast_test.cc @@ -0,0 +1,107 @@ +// Copyright 2017 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Unit test for bit_cast template. + +#include <cstdint> +#include <cstring> + +#include "gtest/gtest.h" +#include "absl/base/casts.h" +#include "absl/base/macros.h" + +namespace absl { +namespace { + +template <int N> +struct marshall { char buf[N]; }; + +template <typename T> +void TestMarshall(const T values[], int num_values) { + for (int i = 0; i < num_values; ++i) { + T t0 = values[i]; + marshall<sizeof(T)> m0 = absl::bit_cast<marshall<sizeof(T)> >(t0); + T t1 = absl::bit_cast<T>(m0); + marshall<sizeof(T)> m1 = absl::bit_cast<marshall<sizeof(T)> >(t1); + ASSERT_EQ(0, memcmp(&t0, &t1, sizeof(T))); + ASSERT_EQ(0, memcmp(&m0, &m1, sizeof(T))); + } +} + +// Convert back and forth to an integral type. The C++ standard does +// not guarantee this will work, but we test that this works on all the +// platforms we support. +// +// Likewise, we below make assumptions about sizeof(float) and +// sizeof(double) which the standard does not guarantee, but which hold on the +// platforms we support. + +template <typename T, typename I> +void TestIntegral(const T values[], int num_values) { + for (int i = 0; i < num_values; ++i) { + T t0 = values[i]; + I i0 = absl::bit_cast<I>(t0); + T t1 = absl::bit_cast<T>(i0); + I i1 = absl::bit_cast<I>(t1); + ASSERT_EQ(0, memcmp(&t0, &t1, sizeof(T))); + ASSERT_EQ(i0, i1); + } +} + +TEST(BitCast, Bool) { + static const bool bool_list[] = { false, true }; + TestMarshall<bool>(bool_list, ABSL_ARRAYSIZE(bool_list)); +} + +TEST(BitCast, Int32) { + static const int32_t int_list[] = + { 0, 1, 100, 2147483647, -1, -100, -2147483647, -2147483647-1 }; + TestMarshall<int32_t>(int_list, ABSL_ARRAYSIZE(int_list)); +} + +TEST(BitCast, Int64) { + static const int64_t int64_list[] = + { 0, 1, 1LL << 40, -1, -(1LL<<40) }; + TestMarshall<int64_t>(int64_list, ABSL_ARRAYSIZE(int64_list)); +} + +TEST(BitCast, Uint64) { + static const uint64_t uint64_list[] = + { 0, 1, 1LLU << 40, 1LLU << 63 }; + TestMarshall<uint64_t>(uint64_list, ABSL_ARRAYSIZE(uint64_list)); +} + +TEST(BitCast, Float) { + static const float float_list[] = + { 0.0f, 1.0f, -1.0f, 10.0f, -10.0f, + 1e10f, 1e20f, 1e-10f, 1e-20f, + 2.71828f, 3.14159f }; + TestMarshall<float>(float_list, ABSL_ARRAYSIZE(float_list)); + TestIntegral<float, int>(float_list, ABSL_ARRAYSIZE(float_list)); + TestIntegral<float, unsigned>(float_list, ABSL_ARRAYSIZE(float_list)); +} + +TEST(BitCast, Double) { + static const double double_list[] = + { 0.0, 1.0, -1.0, 10.0, -10.0, + 1e10, 1e100, 1e-10, 1e-100, + 2.718281828459045, + 3.141592653589793238462643383279502884197169399375105820974944 }; + TestMarshall<double>(double_list, ABSL_ARRAYSIZE(double_list)); + TestIntegral<double, int64_t>(double_list, ABSL_ARRAYSIZE(double_list)); + TestIntegral<double, uint64_t>(double_list, ABSL_ARRAYSIZE(double_list)); +} + +} // namespace +} // namespace absl |