Move wtf/BitwiseOperations.h into base/bits.h.

base/bits_unittest.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains the unit tests for the bit utilities.
 
 #include "base/bits.h"
 
 #include <stddef.h>
 
@@ skipping 43 matching lines @@
   EXPECT_EQ(0ul, Align(0, 4));
   EXPECT_EQ(4ul, Align(1, 4));
   EXPECT_EQ(4096ul, Align(1, 4096));
   EXPECT_EQ(4096ul, Align(4096, 4096));
   EXPECT_EQ(4096ul, Align(4095, 4096));
   EXPECT_EQ(8192ul, Align(4097, 4096));
   EXPECT_EQ(kSizeTMax - 31, Align(kSizeTMax - 62, 32));
   EXPECT_EQ(kSizeTMax / 2 + 1, Align(1, kSizeTMax / 2 + 1));
 }
 
+TEST(BitsTest, CLZWorks) {
+  EXPECT_EQ(32u, CountLeadingZeroBits32(0u));
+  EXPECT_EQ(31u, CountLeadingZeroBits32(1u));
+  EXPECT_EQ(1u, CountLeadingZeroBits32(1u << 30));
+  EXPECT_EQ(0u, CountLeadingZeroBits32(1u << 31));
+
+#if defined(ARCH_CPU_64_BITS)
+  EXPECT_EQ(64u, CountLeadingZeroBitsSizeT(0ull));
+  EXPECT_EQ(63u, CountLeadingZeroBitsSizeT(1ull));
+  EXPECT_EQ(32u, CountLeadingZeroBitsSizeT(1ull << 31));
+  EXPECT_EQ(1u, CountLeadingZeroBitsSizeT(1ull << 62));
+  EXPECT_EQ(0u, CountLeadingZeroBitsSizeT(1ull << 63));
+#else
+  EXPECT_EQ(32u, CountLeadingZeroBitsSizeT(0u));
+  EXPECT_EQ(31u, CountLeadingZeroBitsSizeT(1u));
+  EXPECT_EQ(1u, CountLeadingZeroBitsSizeT(1u << 30));
+  EXPECT_EQ(0u, CountLeadingZeroBitsSizeT(1u << 31));
+#endif
+}
+
 }  // namespace bits
 }  // namespace base