First step to cleanup the power-of-2 mess.

src/base/bits-unittest.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "testing/gtest-support.h"
 
+#ifdef DEBUG
+#define DISABLE_IN_RELEASE(Name) Name
+#else
+#define DISABLE_IN_RELEASE(Name) DISABLED_##Name
+#endif
+
 namespace v8 {
 namespace base {
 namespace bits {
 
-TEST(BitsTest, CountPopulation32) {
+TEST(Bits, CountPopulation32) {
   EXPECT_EQ(0u, CountPopulation32(0));
   EXPECT_EQ(1u, CountPopulation32(1));
   EXPECT_EQ(8u, CountPopulation32(0x11111111));
   EXPECT_EQ(16u, CountPopulation32(0xf0f0f0f0));
   EXPECT_EQ(24u, CountPopulation32(0xfff0f0ff));
   EXPECT_EQ(32u, CountPopulation32(0xffffffff));
 }
 
 
-TEST(BitsTest, CountLeadingZeros32) {
+TEST(Bits, CountLeadingZeros32) {
   EXPECT_EQ(32u, CountLeadingZeros32(0));
   EXPECT_EQ(31u, CountLeadingZeros32(1));
   TRACED_FORRANGE(uint32_t, shift, 0, 31) {
     EXPECT_EQ(31u - shift, CountLeadingZeros32(1u << shift));
   }
   EXPECT_EQ(4u, CountLeadingZeros32(0x0f0f0f0f));
 }
 
 
-TEST(BitsTest, CountTrailingZeros32) {
+TEST(Bits, CountTrailingZeros32) {
   EXPECT_EQ(32u, CountTrailingZeros32(0));
   EXPECT_EQ(31u, CountTrailingZeros32(0x80000000));
   TRACED_FORRANGE(uint32_t, shift, 0, 31) {
     EXPECT_EQ(shift, CountTrailingZeros32(1u << shift));
   }
   EXPECT_EQ(4u, CountTrailingZeros32(0xf0f0f0f0));
 }
 
 
-TEST(BitsTest, RotateRight32) {
+TEST(Bits, IsPowerOfTwo32) {
+  EXPECT_FALSE(IsPowerOfTwo32(0U));
+  TRACED_FORRANGE(uint32_t, shift, 0, 31) {
+    EXPECT_TRUE(IsPowerOfTwo32(1U << shift));
+    EXPECT_FALSE(IsPowerOfTwo32((1U << shift) + 5U));
+    EXPECT_FALSE(IsPowerOfTwo32(~(1U << shift)));
+  }
+  TRACED_FORRANGE(uint32_t, shift, 2, 31) {
+    EXPECT_FALSE(IsPowerOfTwo32((1U << shift) - 1U));
+  }
+  EXPECT_FALSE(IsPowerOfTwo32(0xffffffff));
+}
+
+
+TEST(Bits, IsPowerOfTwo64) {
+  EXPECT_FALSE(IsPowerOfTwo64(0U));
+  TRACED_FORRANGE(uint32_t, shift, 0, 63) {
+    EXPECT_TRUE(IsPowerOfTwo64(V8_UINT64_C(1) << shift));
+    EXPECT_FALSE(IsPowerOfTwo64((V8_UINT64_C(1) << shift) + 5U));
+    EXPECT_FALSE(IsPowerOfTwo64(~(V8_UINT64_C(1) << shift)));
+  }
+  TRACED_FORRANGE(uint32_t, shift, 2, 63) {
+    EXPECT_FALSE(IsPowerOfTwo64((V8_UINT64_C(1) << shift) - 1U));
+  }
+  EXPECT_FALSE(IsPowerOfTwo64(V8_UINT64_C(0xffffffffffffffff)));
+}
+
+
+TEST(Bits, RoundUpToPowerOfTwo32) {
+  TRACED_FORRANGE(uint32_t, shift, 0, 31) {
+    EXPECT_EQ(1u << shift, RoundUpToPowerOfTwo32(1u << shift));
+  }
+  EXPECT_EQ(0u, RoundUpToPowerOfTwo32(0));
+  EXPECT_EQ(4u, RoundUpToPowerOfTwo32(3));
+  EXPECT_EQ(0x80000000u, RoundUpToPowerOfTwo32(0x7fffffffu));
+}
+
+
+TEST(BitsDeathTest, DISABLE_IN_RELEASE(RoundUpToPowerOfTwo32)) {
+  ASSERT_DEATH({ RoundUpToPowerOfTwo32(0x80000001u); }, "0x80000000");
+}
+
+
+TEST(Bits, RoundDownToPowerOfTwo32) {
+  TRACED_FORRANGE(uint32_t, shift, 0, 31) {
+    EXPECT_EQ(1u << shift, RoundDownToPowerOfTwo32(1u << shift));
+  }
+  EXPECT_EQ(0u, RoundDownToPowerOfTwo32(0));
+  EXPECT_EQ(4u, RoundDownToPowerOfTwo32(5));
+  EXPECT_EQ(0x80000000u, RoundDownToPowerOfTwo32(0x80000001u));
+}
+
+
+TEST(Bits, RotateRight32) {
   TRACED_FORRANGE(uint32_t, shift, 0, 31) {
     EXPECT_EQ(0u, RotateRight32(0u, shift));
   }
   EXPECT_EQ(1u, RotateRight32(1, 0));
   EXPECT_EQ(1u, RotateRight32(2, 1));
   EXPECT_EQ(0x80000000u, RotateRight32(1, 1));
 }
 
 
-TEST(BitsTest, RotateRight64) {
+TEST(Bits, RotateRight64) {
   TRACED_FORRANGE(uint64_t, shift, 0, 63) {
     EXPECT_EQ(0u, RotateRight64(0u, shift));
   }
   EXPECT_EQ(1u, RotateRight64(1, 0));
   EXPECT_EQ(1u, RotateRight64(2, 1));
   EXPECT_EQ(V8_UINT64_C(0x8000000000000000), RotateRight64(1, 1));
 }
 
 }  // namespace bits
 }  // namespace base
 }  // namespace v8