1 files changed, 78 insertions, 0 deletions
diff --git a/src/base/test/math_utils_test.cpp b/src/base/test/math_utils_test.cpp
new file mode 100644
index 0000000..0371e11
--- /dev/null
+++ b/src/base/test/math_utils_test.cpp
@@ -0,0 +1,78 @@
+// Copyright 2018 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#include "src/base/math_utils.h"
+
+#include <gtest/gtest.h>
+
+namespace astc_codec {
+namespace base {
+
+TEST(MathUtils, Log2Floor) {
+  EXPECT_EQ(-1, Log2Floor(0));
+
+  for (int i = 0; i < 32; i++) {
+    uint32_t n = 1U << i;
+    EXPECT_EQ(i, Log2Floor(n));
+    if (n > 2) {
+      EXPECT_EQ(i - 1, Log2Floor(n - 1));
+      EXPECT_EQ(i,     Log2Floor(n + 1));
+    }
+  }
+}
+
+TEST(MathUtils, CountOnes) {
+  EXPECT_EQ(0, CountOnes(0));
+  EXPECT_EQ(1, CountOnes(1));
+  EXPECT_EQ(32, CountOnes(static_cast<uint32_t>(~0U)));
+  EXPECT_EQ(1, CountOnes(0x8000000));
+
+  for (int i = 0; i < 32; i++) {
+    EXPECT_EQ(1, CountOnes(1U << i));
+    EXPECT_EQ(31, CountOnes(static_cast<uint32_t>(~0U) ^ (1U << i)));
+  }
+}
+
+TEST(MathUtils, ReverseBits) {
+  EXPECT_EQ(ReverseBits(0u), 0u);
+  EXPECT_EQ(ReverseBits(1u), 1u << 31);
+  EXPECT_EQ(ReverseBits(0xffffffff), 0xffffffff);
+  EXPECT_EQ(ReverseBits(0x00000001), 0x80000000);
+  EXPECT_EQ(ReverseBits(0x80000000), 0x00000001);
+  EXPECT_EQ(ReverseBits(0xaaaaaaaa), 0x55555555);
+  EXPECT_EQ(ReverseBits(0x55555555), 0xaaaaaaaa);
+  EXPECT_EQ(ReverseBits(0x7d5d7f53), 0xcafebabe);
+  EXPECT_EQ(ReverseBits(0xcafebabe), 0x7d5d7f53);
+}
+
+TEST(MathUtils, GetBits) {
+  EXPECT_EQ(GetBits(0u, 0, 1), 0u);
+  EXPECT_EQ(GetBits(0u, 0, 32), 0u);
+  EXPECT_EQ(GetBits(0x00000001u, 0, 1), 0x00000001);
+  EXPECT_EQ(GetBits(0x00000001u, 0, 32), 0x00000001);
+  EXPECT_EQ(GetBits(0x00000001u, 1, 31), 0x00000000);
+  EXPECT_EQ(GetBits(0x00000001u, 31, 1), 0x00000000);
+
+  EXPECT_DEBUG_DEATH(GetBits(0x00000000u, 1, 32), "");
+  EXPECT_DEBUG_DEATH(GetBits(0x00000000u, 32, 0), "");
+  EXPECT_DEBUG_DEATH(GetBits(0x00000000u, 32, 1), "");
+
+  EXPECT_EQ(GetBits(0XFFFFFFFFu, 0, 4), 0x0000000F);
+  EXPECT_EQ(GetBits(0XFFFFFFFFu, 16, 16), 0xFFFF);
+  EXPECT_EQ(GetBits(0x80000000u, 31, 1), 1);
+  EXPECT_EQ(GetBits(0xCAFEBABEu, 24, 8), 0xCA);
+}
+
+}  // namespace base
+}  // namespace astc_codec