Export of internal Abseil changes

--
dab5caab05d89d03066ef92584660688595a3aaf by Mark Barolak <mbar@google.com>:

Add absl::Status and absl::StatusOr to absl/README.md

Import of https://github.com/abseil/abseil-cpp/pull/863

PiperOrigin-RevId: 347857368

--
1ca3c7a96417cd6e6d62f4dc36fd5ddaa61cfa20 by Chris Kennelly <ckennelly@google.com>:

Leverage integer power-of-2 functions and bit counting library in Abseil.

PiperOrigin-RevId: 347816486

--
e5cbe05879fd65dce7875e2e0105331a1615d89b by Chris Kennelly <ckennelly@google.com>:

Mitigate narrowing warning on MSVC.

If sizeof(x) <= sizeof(uint32_t), no truncation occurs when casting to
uint32_t, but the compiler cannot always determine this.

PiperOrigin-RevId: 347696526

--
079dff64cb175d282d9e22dfb4a522199ffdae2e by Benjamin Barenblat <bbaren@google.com>:

Avoid libgcc -NaN narrowing bug

When testing -NaN parsing, avoid narrowing -NaN from double to float.
This avoids a bug in libgcc
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98251).

PiperOrigin-RevId: 347654751

--
2e78a7634865aeef6765e1f447e96cf8d9985059 by Chris Kennelly <ckennelly@google.com>:

Mark popcount helpers as inline.

These are conditionally constexpr, so we need to add inline to cover the
non-constexpr builds to avoid ODR violations.

PiperOrigin-RevId: 347620138

--
437fbb363aea1654179f102dcdd607ec33c1af1e by Chris Kennelly <ckennelly@google.com>:

Use explicit narrowing cast.

This is never invoked in practice, but compilers with -Wimplicit-int-conversion
may trigger when sizeof(T) > sizeof(uint16_t) prior to determining this never
runs.

PiperOrigin-RevId: 347609857
GitOrigin-RevId: dab5caab05d89d03066ef92584660688595a3aaf
Change-Id: I6296ddffe7ec646f8ce121138f21e1e85a2cff4b

31 files changed, 75 insertions, 476 deletions

diff --git a/CMake/AbseilDll.cmake b/CMake/AbseilDll.cmake
index 5296caf1..7c98b21a 100644
--- a/CMake/AbseilDll.cmake
+++ b/CMake/AbseilDll.cmake
@@ -10,7 +10,6 @@ set(ABSL_INTERNAL_DLL_FILES
   "base/const_init.h"
   "base/dynamic_annotations.h"
   "base/internal/atomic_hook.h"
-  "base/internal/bits.h"
   "base/internal/cycleclock.cc"
   "base/internal/cycleclock.h"
   "base/internal/direct_mmap.h"
diff --git a/README.md b/README.md
index 57771f1c..f1802349 100644
--- a/README.md
+++ b/README.md
@@ -80,8 +80,8 @@ Abseil contains the following C++ library components:
 * [`numeric`](absl/numeric/)
   <br /> The `numeric` library contains C++11-compatible 128-bit integers.
 * [`status`](absl/status/)
-  <br /> The `status` library is used within Google for error handling utilizing the 
-  following two main abstractions: `absl::Status` and `absl::StatusOr<T>`. 
+  <br /> The `status` contains abstractions for error handling, specifically
+  `absl::Status` and `absl::StatusOr<T>`.
 * [`strings`](absl/strings/)
   <br /> The `strings` library contains a variety of strings routines and
   utilities, including a C++11-compatible version of the C++17
diff --git a/absl/base/BUILD.bazel b/absl/base/BUILD.bazel
index 9d96abeb..244aa8cc 100644
--- a/absl/base/BUILD.bazel
+++ b/absl/base/BUILD.bazel
@@ -587,31 +587,6 @@ cc_test(
 )
 
 cc_library(
-    name = "bits",
-    hdrs = ["internal/bits.h"],
-    linkopts = ABSL_DEFAULT_LINKOPTS,
-    visibility = [
-        "//absl:__subpackages__",
-    ],
-    deps = [
-        ":config",
-        ":core_headers",
-    ],
-)
-
-cc_test(
-    name = "bits_test",
-    size = "small",
-    srcs = ["internal/bits_test.cc"],
-    copts = ABSL_TEST_COPTS,
-    linkopts = ABSL_DEFAULT_LINKOPTS,
-    deps = [
-        ":bits",
-        "@com_google_googletest//:gtest_main",
-    ],
-)
-
-cc_library(
     name = "exponential_biased",
     srcs = ["internal/exponential_biased.cc"],
     hdrs = ["internal/exponential_biased.h"],
diff --git a/absl/base/CMakeLists.txt b/absl/base/CMakeLists.txt
index 515d7b4e..3d930b85 100644
--- a/absl/base/CMakeLists.txt
+++ b/absl/base/CMakeLists.txt
@@ -520,30 +520,6 @@ absl_cc_test(
 
 absl_cc_library(
   NAME
-    internal_bits
-  HDRS
-    "internal/bits.h"
-  COPTS
-    ${ABSL_DEFAULT_COPTS}
-  DEPS
-    absl::config
-    absl::core_headers
-)
-
-absl_cc_test(
-  NAME
-    internal_bits_test
-  SRCS
-    "internal/bits_test.cc"
-  COPTS
-    ${ABSL_TEST_COPTS}
-  DEPS
-    absl::internal_bits
-    gtest_main
-)
-
-absl_cc_library(
-  NAME
     exponential_biased
   SRCS
     "internal/exponential_biased.cc"
diff --git a/absl/base/internal/bits.h b/absl/base/internal/bits.h
deleted file mode 100644
index 81648e2c..00000000
--- a/absl/base/internal/bits.h
+++ /dev/null
@@ -1,219 +0,0 @@
-// Copyright 2018 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
-//
-//      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.
-
-#ifndef ABSL_BASE_INTERNAL_BITS_H_
-#define ABSL_BASE_INTERNAL_BITS_H_
-
-// This file contains bitwise ops which are implementation details of various
-// absl libraries.
-
-#include <cstdint>
-
-#include "absl/base/config.h"
-
-// Clang on Windows has __builtin_clzll; otherwise we need to use the
-// windows intrinsic functions.
-#if defined(_MSC_VER) && !defined(__clang__)
-#include <intrin.h>
-#if defined(_M_X64)
-#pragma intrinsic(_BitScanReverse64)
-#pragma intrinsic(_BitScanForward64)
-#endif
-#pragma intrinsic(_BitScanReverse)
-#pragma intrinsic(_BitScanForward)
-#endif
-
-#include "absl/base/attributes.h"
-
-#if defined(_MSC_VER) && !defined(__clang__)
-// We can achieve something similar to attribute((always_inline)) with MSVC by
-// using the __forceinline keyword, however this is not perfect. MSVC is
-// much less aggressive about inlining, and even with the __forceinline keyword.
-#define ABSL_BASE_INTERNAL_FORCEINLINE __forceinline
-#else
-// Use default attribute inline.
-#define ABSL_BASE_INTERNAL_FORCEINLINE inline ABSL_ATTRIBUTE_ALWAYS_INLINE
-#endif
-
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace base_internal {
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros64Slow(uint64_t n) {
-  int zeroes = 60;
-  if (n >> 32) {
-    zeroes -= 32;
-    n >>= 32;
-  }
-  if (n >> 16) {
-    zeroes -= 16;
-    n >>= 16;
-  }
-  if (n >> 8) {
-    zeroes -= 8;
-    n >>= 8;
-  }
-  if (n >> 4) {
-    zeroes -= 4;
-    n >>= 4;
-  }
-  return "\4\3\2\2\1\1\1\1\0\0\0\0\0\0\0"[n] + zeroes;
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros64(uint64_t n) {
-#if defined(_MSC_VER) && !defined(__clang__) && defined(_M_X64)
-  // MSVC does not have __buitin_clzll. Use _BitScanReverse64.
-  unsigned long result = 0;  // NOLINT(runtime/int)
-  if (_BitScanReverse64(&result, n)) {
-    return 63 - result;
-  }
-  return 64;
-#elif defined(_MSC_VER) && !defined(__clang__)
-  // MSVC does not have __buitin_clzll. Compose two calls to _BitScanReverse
-  unsigned long result = 0;  // NOLINT(runtime/int)
-  if ((n >> 32) &&
-      _BitScanReverse(&result, static_cast<unsigned long>(n >> 32))) {
-    return 31 - result;
-  }
-  if (_BitScanReverse(&result, static_cast<unsigned long>(n))) {
-    return 63 - result;
-  }
-  return 64;
-#elif defined(__GNUC__) || defined(__clang__)
-  // Use __builtin_clzll, which uses the following instructions:
-  //  x86: bsr
-  //  ARM64: clz
-  //  PPC: cntlzd
-  static_assert(sizeof(unsigned long long) == sizeof(n),  // NOLINT(runtime/int)
-                "__builtin_clzll does not take 64-bit arg");
-
-  // Handle 0 as a special case because __builtin_clzll(0) is undefined.
-  if (n == 0) {
-    return 64;
-  }
-  return __builtin_clzll(n);
-#else
-  return CountLeadingZeros64Slow(n);
-#endif
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros32Slow(uint64_t n) {
-  int zeroes = 28;
-  if (n >> 16) {
-    zeroes -= 16;
-    n >>= 16;
-  }
-  if (n >> 8) {
-    zeroes -= 8;
-    n >>= 8;
-  }
-  if (n >> 4) {
-    zeroes -= 4;
-    n >>= 4;
-  }
-  return "\4\3\2\2\1\1\1\1\0\0\0\0\0\0\0"[n] + zeroes;
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros32(uint32_t n) {
-#if defined(_MSC_VER) && !defined(__clang__)
-  unsigned long result = 0;  // NOLINT(runtime/int)
-  if (_BitScanReverse(&result, n)) {
-    return 31 - result;
-  }
-  return 32;
-#elif defined(__GNUC__) || defined(__clang__)
-  // Use __builtin_clz, which uses the following instructions:
-  //  x86: bsr
-  //  ARM64: clz
-  //  PPC: cntlzd
-  static_assert(sizeof(int) == sizeof(n),
-                "__builtin_clz does not take 32-bit arg");
-
-  // Handle 0 as a special case because __builtin_clz(0) is undefined.
-  if (n == 0) {
-    return 32;
-  }
-  return __builtin_clz(n);
-#else
-  return CountLeadingZeros32Slow(n);
-#endif
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero64Slow(uint64_t n) {
-  int c = 63;
-  n &= ~n + 1;
-  if (n & 0x00000000FFFFFFFF) c -= 32;
-  if (n & 0x0000FFFF0000FFFF) c -= 16;
-  if (n & 0x00FF00FF00FF00FF) c -= 8;
-  if (n & 0x0F0F0F0F0F0F0F0F) c -= 4;
-  if (n & 0x3333333333333333) c -= 2;
-  if (n & 0x5555555555555555) c -= 1;
-  return c;
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero64(uint64_t n) {
-#if defined(_MSC_VER) && !defined(__clang__) && defined(_M_X64)
-  unsigned long result = 0;  // NOLINT(runtime/int)
-  _BitScanForward64(&result, n);
-  return result;
-#elif defined(_MSC_VER) && !defined(__clang__)
-  unsigned long result = 0;  // NOLINT(runtime/int)
-  if (static_cast<uint32_t>(n) == 0) {
-    _BitScanForward(&result, static_cast<unsigned long>(n >> 32));
-    return result + 32;
-  }
-  _BitScanForward(&result, static_cast<unsigned long>(n));
-  return result;
-#elif defined(__GNUC__) || defined(__clang__)
-  static_assert(sizeof(unsigned long long) == sizeof(n),  // NOLINT(runtime/int)
-                "__builtin_ctzll does not take 64-bit arg");
-  return __builtin_ctzll(n);
-#else
-  return CountTrailingZerosNonZero64Slow(n);
-#endif
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero32Slow(uint32_t n) {
-  int c = 31;
-  n &= ~n + 1;
-  if (n & 0x0000FFFF) c -= 16;
-  if (n & 0x00FF00FF) c -= 8;
-  if (n & 0x0F0F0F0F) c -= 4;
-  if (n & 0x33333333) c -= 2;
-  if (n & 0x55555555) c -= 1;
-  return c;
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero32(uint32_t n) {
-#if defined(_MSC_VER) && !defined(__clang__)
-  unsigned long result = 0;  // NOLINT(runtime/int)
-  _BitScanForward(&result, n);
-  return result;
-#elif defined(__GNUC__) || defined(__clang__)
-  static_assert(sizeof(int) == sizeof(n),
-                "__builtin_ctz does not take 32-bit arg");
-  return __builtin_ctz(n);
-#else
-  return CountTrailingZerosNonZero32Slow(n);
-#endif
-}
-
-#undef ABSL_BASE_INTERNAL_FORCEINLINE
-
-}  // namespace base_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_BASE_INTERNAL_BITS_H_
diff --git a/absl/base/internal/bits_test.cc b/absl/base/internal/bits_test.cc
deleted file mode 100644
index 7855fa62..00000000
--- a/absl/base/internal/bits_test.cc
+++ /dev/null
@@ -1,97 +0,0 @@
-// Copyright 2018 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
-//
-//      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 "absl/base/internal/bits.h"
-
-#include "gtest/gtest.h"
-
-namespace {
-
-int CLZ64(uint64_t n) {
-  int fast = absl::base_internal::CountLeadingZeros64(n);
-  int slow = absl::base_internal::CountLeadingZeros64Slow(n);
-  EXPECT_EQ(fast, slow) << n;
-  return fast;
-}
-
-TEST(BitsTest, CountLeadingZeros64) {
-  EXPECT_EQ(64, CLZ64(uint64_t{}));
-  EXPECT_EQ(0, CLZ64(~uint64_t{}));
-
-  for (int index = 0; index < 64; index++) {
-    uint64_t x = static_cast<uint64_t>(1) << index;
-    const auto cnt = 63 - index;
-    ASSERT_EQ(cnt, CLZ64(x)) << index;
-    ASSERT_EQ(cnt, CLZ64(x + x - 1)) << index;
-  }
-}
-
-int CLZ32(uint32_t n) {
-  int fast = absl::base_internal::CountLeadingZeros32(n);
-  int slow = absl::base_internal::CountLeadingZeros32Slow(n);
-  EXPECT_EQ(fast, slow) << n;
-  return fast;
-}
-
-TEST(BitsTest, CountLeadingZeros32) {
-  EXPECT_EQ(32, CLZ32(uint32_t{}));
-  EXPECT_EQ(0, CLZ32(~uint32_t{}));
-
-  for (int index = 0; index < 32; index++) {
-    uint32_t x = static_cast<uint32_t>(1) << index;
-    const auto cnt = 31 - index;
-    ASSERT_EQ(cnt, CLZ32(x)) << index;
-    ASSERT_EQ(cnt, CLZ32(x + x - 1)) << index;
-    ASSERT_EQ(CLZ64(x), CLZ32(x) + 32);
-  }
-}
-
-int CTZ64(uint64_t n) {
-  int fast = absl::base_internal::CountTrailingZerosNonZero64(n);
-  int slow = absl::base_internal::CountTrailingZerosNonZero64Slow(n);
-  EXPECT_EQ(fast, slow) << n;
-  return fast;
-}
-
-TEST(BitsTest, CountTrailingZerosNonZero64) {
-  EXPECT_EQ(0, CTZ64(~uint64_t{}));
-
-  for (int index = 0; index < 64; index++) {
-    uint64_t x = static_cast<uint64_t>(1) << index;
-    const auto cnt = index;
-    ASSERT_EQ(cnt, CTZ64(x)) << index;
-    ASSERT_EQ(cnt, CTZ64(~(x - 1))) << index;
-  }
-}
-
-int CTZ32(uint32_t n) {
-  int fast = absl::base_internal::CountTrailingZerosNonZero32(n);
-  int slow = absl::base_internal::CountTrailingZerosNonZero32Slow(n);
-  EXPECT_EQ(fast, slow) << n;
-  return fast;
-}
-
-TEST(BitsTest, CountTrailingZerosNonZero32) {
-  EXPECT_EQ(0, CTZ32(~uint32_t{}));
-
-  for (int index = 0; index < 32; index++) {
-    uint32_t x = static_cast<uint32_t>(1) << index;
-    const auto cnt = index;
-    ASSERT_EQ(cnt, CTZ32(x)) << index;
-    ASSERT_EQ(cnt, CTZ32(~(x - 1))) << index;
-  }
-}
-
-
-}  // namespace
diff --git a/absl/container/BUILD.bazel b/absl/container/BUILD.bazel
index 70977143..f22fdc60 100644
--- a/absl/container/BUILD.bazel
+++ b/absl/container/BUILD.bazel
@@ -599,12 +599,12 @@ cc_library(
         ":hashtablez_sampler",
         ":have_sse",
         ":layout",
-        "//absl/base:bits",
         "//absl/base:config",
         "//absl/base:core_headers",
         "//absl/base:endian",
         "//absl/memory",
         "//absl/meta:type_traits",
+        "//absl/numeric:bits",
         "//absl/utility",
     ],
 )
diff --git a/absl/container/CMakeLists.txt b/absl/container/CMakeLists.txt
index 7562f32d..eb202c45 100644
--- a/absl/container/CMakeLists.txt
+++ b/absl/container/CMakeLists.txt
@@ -665,7 +665,7 @@ absl_cc_library(
   COPTS
     ${ABSL_DEFAULT_COPTS}
   DEPS
-    absl::internal_bits
+    absl::bits
     absl::compressed_tuple
     absl::config
     absl::container_common
diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index a958daaf..4477f7dc 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -102,7 +102,6 @@
 #include <type_traits>
 #include <utility>
 
-#include "absl/base/internal/bits.h"
 #include "absl/base/internal/endian.h"
 #include "absl/base/optimization.h"
 #include "absl/base/port.h"
@@ -116,6 +115,7 @@
 #include "absl/container/internal/layout.h"
 #include "absl/memory/memory.h"
 #include "absl/meta/type_traits.h"
+#include "absl/numeric/bits.h"
 #include "absl/utility/utility.h"
 
 namespace absl {
@@ -190,17 +190,8 @@ constexpr bool IsNoThrowSwappable(std::false_type /* is_swappable */) {
 
 template <typename T>
 int TrailingZeros(T x) {
-  return sizeof(T) == 8 ? base_internal::CountTrailingZerosNonZero64(
-                              static_cast<uint64_t>(x))
-                        : base_internal::CountTrailingZerosNonZero32(
-                              static_cast<uint32_t>(x));
-}
-
-template <typename T>
-int LeadingZeros(T x) {
-  return sizeof(T) == 8
-             ? base_internal::CountLeadingZeros64(static_cast<uint64_t>(x))
-             : base_internal::CountLeadingZeros32(static_cast<uint32_t>(x));
+  ABSL_INTERNAL_ASSUME(x != 0);
+  return countr_zero(x);
 }
 
 // An abstraction over a bitmask. It provides an easy way to iterate through the
@@ -233,11 +224,7 @@ class BitMask {
   int LowestBitSet() const {
     return container_internal::TrailingZeros(mask_) >> Shift;
   }
-  int HighestBitSet() const {
-    return (sizeof(T) * CHAR_BIT - container_internal::LeadingZeros(mask_) -
-            1) >>
-           Shift;
-  }
+  int HighestBitSet() const { return (bit_width(mask_) - 1) >> Shift; }
 
   BitMask begin() const { return *this; }
   BitMask end() const { return BitMask(0); }
@@ -249,7 +236,7 @@ class BitMask {
   int LeadingZeros() const {
     constexpr int total_significant_bits = SignificantBits << Shift;
     constexpr int extra_bits = sizeof(T) * 8 - total_significant_bits;
-    return container_internal::LeadingZeros(mask_ << extra_bits) >> Shift;
+    return countl_zero(mask_ << extra_bits) >> Shift;
   }
 
  private:
@@ -380,8 +367,8 @@ struct GroupSse2Impl {
   // Returns the number of trailing empty or deleted elements in the group.
   uint32_t CountLeadingEmptyOrDeleted() const {
     auto special = _mm_set1_epi8(kSentinel);
-    return TrailingZeros(
-        _mm_movemask_epi8(_mm_cmpgt_epi8_fixed(special, ctrl)) + 1);
+    return TrailingZeros(static_cast<uint32_t>(
+        _mm_movemask_epi8(_mm_cmpgt_epi8_fixed(special, ctrl)) + 1));
   }
 
   void ConvertSpecialToEmptyAndFullToDeleted(ctrl_t* dst) const {
@@ -476,7 +463,7 @@ void ConvertDeletedToEmptyAndFullToDeleted(ctrl_t* ctrl, size_t capacity);
 
 // Rounds up the capacity to the next power of 2 minus 1, with a minimum of 1.
 inline size_t NormalizeCapacity(size_t n) {
-  return n ? ~size_t{} >> LeadingZeros(n) : 1;
+  return n ? ~size_t{} >> countl_zero(n) : 1;
 }
 
 // We use 7/8th as maximum load factor.
diff --git a/absl/numeric/BUILD.bazel b/absl/numeric/BUILD.bazel
index fb782ef3..5d7b1857 100644
--- a/absl/numeric/BUILD.bazel
+++ b/absl/numeric/BUILD.bazel
@@ -64,7 +64,7 @@ cc_library(
     copts = ABSL_DEFAULT_COPTS,
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
-        "//absl/base:bits",
+        ":bits",
         "//absl/base:config",
         "//absl/base:core_headers",
     ],
diff --git a/absl/numeric/CMakeLists.txt b/absl/numeric/CMakeLists.txt
index 77e3f5ee..be94352a 100644
--- a/absl/numeric/CMakeLists.txt
+++ b/absl/numeric/CMakeLists.txt
@@ -55,7 +55,7 @@ absl_cc_library(
   DEPS
     absl::config
     absl::core_headers
-    absl::internal_bits
+    absl::bits
   PUBLIC
 )
 
diff --git a/absl/numeric/int128.cc b/absl/numeric/int128.cc
index e21e5e9a..5160df79 100644
--- a/absl/numeric/int128.cc
+++ b/absl/numeric/int128.cc
@@ -23,8 +23,8 @@
 #include <string>
 #include <type_traits>
 
-#include "absl/base/internal/bits.h"
 #include "absl/base/optimization.h"
+#include "absl/numeric/bits.h"
 
 namespace absl {
 ABSL_NAMESPACE_BEGIN
@@ -43,11 +43,11 @@ namespace {
 inline ABSL_ATTRIBUTE_ALWAYS_INLINE int Fls128(uint128 n) {
   if (uint64_t hi = Uint128High64(n)) {
     ABSL_INTERNAL_ASSUME(hi != 0);
-    return 127 - base_internal::CountLeadingZeros64(hi);
+    return 127 - countl_zero(hi);
   }
   const uint64_t low = Uint128Low64(n);
   ABSL_INTERNAL_ASSUME(low != 0);
-  return 63 - base_internal::CountLeadingZeros64(low);
+  return 63 - countl_zero(low);
 }
 
 // Long division/modulo for uint128 implemented using the shift-subtract
diff --git a/absl/numeric/internal/bits.h b/absl/numeric/internal/bits.h
index 60478f52..50828156 100644
--- a/absl/numeric/internal/bits.h
+++ b/absl/numeric/internal/bits.h
@@ -89,7 +89,8 @@ ABSL_MUST_USE_RESULT ABSL_ATTRIBUTE_ALWAYS_INLINE constexpr T RotateLeft(
          static_cast<T>(x >> ((-s) & (std::numeric_limits<T>::digits - 1)));
 }
 
-ABSL_INTERNAL_CONSTEXPR_POPCOUNT int Popcount32(uint32_t x) noexcept {
+ABSL_ATTRIBUTE_ALWAYS_INLINE ABSL_INTERNAL_CONSTEXPR_POPCOUNT inline int
+Popcount32(uint32_t x) noexcept {
 #if ABSL_HAVE_BUILTIN(__builtin_popcount)
   static_assert(sizeof(unsigned int) == sizeof(x),
                 "__builtin_popcount does not take 32-bit arg");
@@ -101,7 +102,8 @@ ABSL_INTERNAL_CONSTEXPR_POPCOUNT int Popcount32(uint32_t x) noexcept {
 #endif
 }
 
-ABSL_INTERNAL_CONSTEXPR_POPCOUNT int Popcount64(uint64_t x) noexcept {
+ABSL_ATTRIBUTE_ALWAYS_INLINE ABSL_INTERNAL_CONSTEXPR_POPCOUNT inline int
+Popcount64(uint64_t x) noexcept {
 #if ABSL_HAVE_BUILTIN(__builtin_popcountll)
   static_assert(sizeof(unsigned long long) == sizeof(x),  // NOLINT(runtime/int)
                 "__builtin_popcount does not take 64-bit arg");
@@ -231,11 +233,11 @@ CountLeadingZeroes(T x) {
                 "T must have a power-of-2 size");
   static_assert(sizeof(T) <= sizeof(uint64_t), "T too large");
   return sizeof(T) <= sizeof(uint16_t)
-             ? CountLeadingZeroes16(x) -
+             ? CountLeadingZeroes16(static_cast<uint16_t>(x)) -
                    (std::numeric_limits<uint16_t>::digits -
                     std::numeric_limits<T>::digits)
              : (sizeof(T) <= sizeof(uint32_t)
-                    ? CountLeadingZeroes32(x) -
+                    ? CountLeadingZeroes32(static_cast<uint32_t>(x)) -
                           (std::numeric_limits<uint32_t>::digits -
                            std::numeric_limits<T>::digits)
                     : CountLeadingZeroes64(x));
@@ -314,9 +316,10 @@ CountTrailingZeroes(T x) noexcept {
   static_assert(sizeof(T) <= sizeof(uint64_t), "T too large");
   return x == 0 ? std::numeric_limits<T>::digits
                 : (sizeof(T) <= sizeof(uint16_t)
-                       ? CountTrailingZeroesNonzero16(x)
+                       ? CountTrailingZeroesNonzero16(static_cast<uint16_t>(x))
                        : (sizeof(T) <= sizeof(uint32_t)
-                              ? CountTrailingZeroesNonzero32(x)
+                              ? CountTrailingZeroesNonzero32(
+                                    static_cast<uint32_t>(x))
                               : CountTrailingZeroesNonzero64(x)));
 }
 
diff --git a/absl/random/BUILD.bazel b/absl/random/BUILD.bazel
index 81e150e6..d97b2c4e 100644
--- a/absl/random/BUILD.bazel
+++ b/absl/random/BUILD.bazel
@@ -69,6 +69,7 @@ cc_library(
         "//absl/base:config",
         "//absl/base:core_headers",
         "//absl/meta:type_traits",
+        "//absl/numeric:bits",
         "//absl/random/internal:distribution_caller",
         "//absl/random/internal:fast_uniform_bits",
         "//absl/random/internal:fastmath",
diff --git a/absl/random/CMakeLists.txt b/absl/random/CMakeLists.txt
index d717a5ce..7d7bec83 100644
--- a/absl/random/CMakeLists.txt
+++ b/absl/random/CMakeLists.txt
@@ -673,7 +673,7 @@ absl_cc_library(
   LINKOPTS
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
-    absl::internal_bits
+    absl::bits
     absl::random_internal_fastmath
     absl::random_internal_traits
     absl::type_traits
@@ -690,7 +690,7 @@ absl_cc_library(
   LINKOPTS
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
-    absl::internal_bits
+    absl::bits
     absl::config
     absl::int128
 )
@@ -706,7 +706,7 @@ absl_cc_library(
   LINKOPTS
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
-    absl::internal_bits
+    absl::bits
 )
 
 # Internal-only target, do not depend on directly.
@@ -902,7 +902,7 @@ absl_cc_test(
   LINKOPTS
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
-    absl::internal_bits
+    absl::bits
     absl::flags
     absl::random_internal_generate_real
     gtest_main
@@ -1201,7 +1201,7 @@ absl_cc_test(
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS
     absl::random_internal_wide_multiply
-    absl::internal_bits
+    absl::bits
     absl::int128
     gtest_main
 )
diff --git a/absl/random/internal/BUILD.bazel b/absl/random/internal/BUILD.bazel
index 8485e28b..2c1a5f4a 100644
--- a/absl/random/internal/BUILD.bazel
+++ b/absl/random/internal/BUILD.bazel
@@ -175,8 +175,8 @@ cc_library(
     deps = [
         ":fastmath",
         ":traits",
-        "//absl/base:bits",
         "//absl/meta:type_traits",
+        "//absl/numeric:bits",
     ],
 )
 
@@ -187,7 +187,7 @@ cc_library(
     ],
     copts = ABSL_DEFAULT_COPTS,
     linkopts = ABSL_DEFAULT_LINKOPTS,
-    deps = ["//absl/base:bits"],
+    deps = ["//absl/numeric:bits"],
 )
 
 cc_library(
@@ -197,8 +197,8 @@ cc_library(
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
         ":traits",
-        "//absl/base:bits",
         "//absl/base:config",
+        "//absl/numeric:bits",
         "//absl/numeric:int128",
     ],
 )
@@ -229,6 +229,7 @@ cc_library(
         ":iostream_state_saver",
         "//absl/base:config",
         "//absl/meta:type_traits",
+        "//absl/numeric:bits",
         "//absl/numeric:int128",
     ],
 )
@@ -400,8 +401,8 @@ cc_test(
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
         ":generate_real",
-        "//absl/base:bits",
         "//absl/flags:flag",
+        "//absl/numeric:bits",
         "@com_google_googletest//:gtest_main",
     ],
 )
@@ -634,7 +635,7 @@ cc_test(
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
         ":wide_multiply",
-        "//absl/base:bits",
+        "//absl/numeric:bits",
         "//absl/numeric:int128",
         "@com_google_googletest//:gtest_main",
     ],
diff --git a/absl/random/internal/fastmath.h b/absl/random/internal/fastmath.h
index 6baeb5a7..963b7690 100644
--- a/absl/random/internal/fastmath.h
+++ b/absl/random/internal/fastmath.h
@@ -22,27 +22,22 @@
 #include <cmath>
 #include <cstdint>
 
-#include "absl/base/internal/bits.h"
+#include "absl/numeric/bits.h"
 
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace random_internal {
 
-// Returns the position of the first bit set.
-inline int LeadingSetBit(uint64_t n) {
-  return 64 - base_internal::CountLeadingZeros64(n);
-}
-
 // Compute log2(n) using integer operations.
 // While std::log2 is more accurate than std::log(n) / std::log(2), for
 // very large numbers--those close to std::numeric_limits<uint64_t>::max() - 2,
 // for instance--std::log2 rounds up rather than down, which introduces
 // definite skew in the results.
 inline int IntLog2Floor(uint64_t n) {
-  return (n <= 1) ? 0 : (63 - base_internal::CountLeadingZeros64(n));
+  return (n <= 1) ? 0 : (63 - countl_zero(n));
 }
 inline int IntLog2Ceil(uint64_t n) {
-  return (n <= 1) ? 0 : (64 - base_internal::CountLeadingZeros64(n - 1));
+  return (n <= 1) ? 0 : (64 - countl_zero(n - 1));
 }
 
 inline double StirlingLogFactorial(double n) {
@@ -55,18 +50,6 @@ inline double StirlingLogFactorial(double n) {
          (1.0 / 360.0) * ninv * ninv * ninv;
 }
 
-// Rotate value right.
-//
-// We only implement the uint32_t / uint64_t versions because
-// 1) those are the only ones we use, and
-// 2) those are the only ones where clang detects the rotate idiom correctly.
-inline constexpr uint32_t rotr(uint32_t value, uint8_t bits) {
-  return (value >> (bits & 31)) | (value << ((-bits) & 31));
-}
-inline constexpr uint64_t rotr(uint64_t value, uint8_t bits) {
-  return (value >> (bits & 63)) | (value << ((-bits) & 63));
-}
-
 }  // namespace random_internal
 ABSL_NAMESPACE_END
 }  // namespace absl
diff --git a/absl/random/internal/fastmath_test.cc b/absl/random/internal/fastmath_test.cc
index 65859c25..0d6f9dc1 100644
--- a/absl/random/internal/fastmath_test.cc
+++ b/absl/random/internal/fastmath_test.cc
@@ -27,19 +27,6 @@
 
 namespace {
 
-TEST(DistributionImplTest, LeadingSetBit) {
-  using absl::random_internal::LeadingSetBit;
-  constexpr uint64_t kZero = 0;
-  EXPECT_EQ(0, LeadingSetBit(kZero));
-  EXPECT_EQ(64, LeadingSetBit(~kZero));
-
-  for (int index = 0; index < 64; index++) {
-    uint64_t x = static_cast<uint64_t>(1) << index;
-    EXPECT_EQ(index + 1, LeadingSetBit(x)) << index;
-    EXPECT_EQ(index + 1, LeadingSetBit(x + x - 1)) << index;
-  }
-}
-
 TEST(FastMathTest, IntLog2FloorTest) {
   using absl::random_internal::IntLog2Floor;
   constexpr uint64_t kZero = 0;
diff --git a/absl/random/internal/generate_real.h b/absl/random/internal/generate_real.h
index 20f6d208..4f62873d 100644
--- a/absl/random/internal/generate_real.h
+++ b/absl/random/internal/generate_real.h
@@ -23,8 +23,8 @@
 #include <limits>
 #include <type_traits>
 
-#include "absl/base/internal/bits.h"
 #include "absl/meta/type_traits.h"
+#include "absl/numeric/bits.h"
 #include "absl/random/internal/fastmath.h"
 #include "absl/random/internal/traits.h"
 
@@ -120,7 +120,7 @@ inline RealType GenerateRealFromBits(uint64_t bits, int exp_bias = 0) {
 
   // Number of leading zeros is mapped to the exponent: 2^-clz
   // bits is 0..01xxxxxx. After shifting, we're left with 1xxx...0..0
-  int clz = base_internal::CountLeadingZeros64(bits);
+  int clz = countl_zero(bits);
   bits <<= (IncludeZero ? clz : (clz & 63));  // remove 0-bits.
   exp -= clz;                                 // set the exponent.
   bits >>= (63 - kExp);
diff --git a/absl/random/internal/generate_real_test.cc b/absl/random/internal/generate_real_test.cc
index 4bdc4534..b099dbf3 100644
--- a/absl/random/internal/generate_real_test.cc
+++ b/absl/random/internal/generate_real_test.cc
@@ -20,8 +20,8 @@
 #include <string>
 
 #include "gtest/gtest.h"
-#include "absl/base/internal/bits.h"
 #include "absl/flags/flag.h"
+#include "absl/numeric/bits.h"
 
 ABSL_FLAG(int64_t, absl_random_test_trials, 50000,
           "Number of trials for the probability tests.");
@@ -413,7 +413,6 @@ TEST(GenerateRealTest, U64ToDoubleSignedTest) {
 }
 
 TEST(GenerateRealTest, ExhaustiveFloat) {
-  using absl::base_internal::CountLeadingZeros64;
   auto ToFloat = [](uint64_t a) {
     return GenerateRealFromBits<float, GeneratePositiveTag, true>(a);
   };
@@ -464,7 +463,7 @@ TEST(GenerateRealTest, ExhaustiveFloat) {
 
     // Adjust decrement and check value based on how many leading 0
     // bits are set in the current value.
-    const int clz = CountLeadingZeros64(x);
+    const int clz = absl::countl_zero(x);
     if (clz < kDig) {
       dec <<= (kDig - clz);
       chk = (~uint64_t(0)) >> (clz + 1);
diff --git a/absl/random/internal/pcg_engine.h b/absl/random/internal/pcg_engine.h
index 53c23fe1..8efaf2e0 100644
--- a/absl/random/internal/pcg_engine.h
+++ b/absl/random/internal/pcg_engine.h
@@ -19,6 +19,7 @@
 
 #include "absl/base/config.h"
 #include "absl/meta/type_traits.h"
+#include "absl/numeric/bits.h"
 #include "absl/numeric/int128.h"
 #include "absl/random/internal/fastmath.h"
 #include "absl/random/internal/iostream_state_saver.h"
@@ -261,7 +262,7 @@ struct pcg_xsl_rr_128_64 {
     uint64_t rotate = h >> 58u;
     uint64_t s = Uint128Low64(state) ^ h;
 #endif
-    return random_internal::rotr(s, rotate);
+    return rotr(s, rotate);
   }
 };
 
@@ -281,8 +282,8 @@ struct pcg_xsh_rr_64_32 {
   using state_type = uint64_t;
   using result_type = uint32_t;
   inline uint32_t operator()(uint64_t state) {
-    return random_internal::rotr(
-        static_cast<uint32_t>(((state >> 18) ^ state) >> 27), state >> 59);
+    return rotr(static_cast<uint32_t>(((state >> 18) ^ state) >> 27),
+                state >> 59);
   }
 };
 
diff --git a/absl/random/internal/wide_multiply.h b/absl/random/internal/wide_multiply.h
index 0afcbe08..b6e6c4b6 100644
--- a/absl/random/internal/wide_multiply.h
+++ b/absl/random/internal/wide_multiply.h
@@ -26,7 +26,7 @@
 #endif
 
 #include "absl/base/config.h"
-#include "absl/base/internal/bits.h"
+#include "absl/numeric/bits.h"
 #include "absl/numeric/int128.h"
 #include "absl/random/internal/traits.h"
 
diff --git a/absl/random/internal/wide_multiply_test.cc b/absl/random/internal/wide_multiply_test.cc
index ca8ce923..e276cb51 100644
--- a/absl/random/internal/wide_multiply_test.cc
+++ b/absl/random/internal/wide_multiply_test.cc
@@ -15,7 +15,6 @@
 #include "absl/random/internal/wide_multiply.h"
 
 #include "gtest/gtest.h"
-#include "absl/base/internal/bits.h"
 #include "absl/numeric/int128.h"
 
 using absl::random_internal::MultiplyU64ToU128;
diff --git a/absl/random/log_uniform_int_distribution.h b/absl/random/log_uniform_int_distribution.h
index 960816e2..43e10116 100644
--- a/absl/random/log_uniform_int_distribution.h
+++ b/absl/random/log_uniform_int_distribution.h
@@ -23,6 +23,7 @@
 #include <ostream>
 #include <type_traits>
 
+#include "absl/numeric/bits.h"
 #include "absl/random/internal/fastmath.h"
 #include "absl/random/internal/generate_real.h"
 #include "absl/random/internal/iostream_state_saver.h"
@@ -68,8 +69,10 @@ class log_uniform_int_distribution {
       if (base_ == 2) {
         // Determine where the first set bit is on range(), giving a log2(range)
         // value which can be used to construct bounds.
-        log_range_ = (std::min)(random_internal::LeadingSetBit(range()),
-                                std::numeric_limits<unsigned_type>::digits);
+        log_range_ =
+            (std::min)(bit_width(range()),
+                       static_cast<unsigned_type>(
+                           std::numeric_limits<unsigned_type>::digits));
       } else {
         // NOTE: Computing the logN(x) introduces error from 2 sources:
         // 1. Conversion of int to double loses precision for values >=
diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel
index 3154d80d..70016791 100644
--- a/absl/strings/BUILD.bazel
+++ b/absl/strings/BUILD.bazel
@@ -69,7 +69,6 @@ cc_library(
     deps = [
         ":internal",
         "//absl/base",
-        "//absl/base:bits",
         "//absl/base:config",
         "//absl/base:core_headers",
         "//absl/base:endian",
@@ -77,6 +76,7 @@ cc_library(
         "//absl/base:throw_delegate",
         "//absl/memory",
         "//absl/meta:type_traits",
+        "//absl/numeric:bits",
         "//absl/numeric:int128",
     ],
 )
@@ -663,11 +663,11 @@ cc_library(
     visibility = ["//visibility:private"],
     deps = [
         ":strings",
-        "//absl/base:bits",
         "//absl/base:config",
         "//absl/base:core_headers",
         "//absl/functional:function_ref",
         "//absl/meta:type_traits",
+        "//absl/numeric:bits",
         "//absl/numeric:int128",
         "//absl/types:optional",
         "//absl/types:span",
diff --git a/absl/strings/CMakeLists.txt b/absl/strings/CMakeLists.txt
index fa61ff61..654d0fd6 100644
--- a/absl/strings/CMakeLists.txt
+++ b/absl/strings/CMakeLists.txt
@@ -56,7 +56,7 @@ absl_cc_library(
   DEPS
     absl::strings_internal
     absl::base
-    absl::internal_bits
+    absl::bits
     absl::config
     absl::core_headers
     absl::endian
@@ -406,7 +406,7 @@ absl_cc_library(
   COPTS
     ${ABSL_DEFAULT_COPTS}
   DEPS
-    absl::internal_bits
+    absl::bits
     absl::strings
     absl::config
     absl::core_headers
diff --git a/absl/strings/charconv.cc b/absl/strings/charconv.cc
index 3613a652..b8674c28 100644
--- a/absl/strings/charconv.cc
+++ b/absl/strings/charconv.cc
@@ -20,7 +20,7 @@
 #include <cstring>
 
 #include "absl/base/casts.h"
-#include "absl/base/internal/bits.h"
+#include "absl/numeric/bits.h"
 #include "absl/numeric/int128.h"
 #include "absl/strings/internal/charconv_bigint.h"
 #include "absl/strings/internal/charconv_parse.h"
@@ -242,11 +242,11 @@ struct CalculatedFloat {
 
 // Returns the bit width of the given uint128.  (Equivalently, returns 128
 // minus the number of leading zero bits.)
-int BitWidth(uint128 value) {
+unsigned BitWidth(uint128 value) {
   if (Uint128High64(value) == 0) {
-    return 64 - base_internal::CountLeadingZeros64(Uint128Low64(value));
+    return static_cast<unsigned>(bit_width(Uint128Low64(value)));
   }
-  return 128 - base_internal::CountLeadingZeros64(Uint128High64(value));
+  return 128 - countl_zero(Uint128High64(value));
 }
 
 // Calculates how far to the right a mantissa needs to be shifted to create a
@@ -519,7 +519,7 @@ CalculatedFloat CalculateFromParsedHexadecimal(
     const strings_internal::ParsedFloat& parsed_hex) {
   uint64_t mantissa = parsed_hex.mantissa;
   int exponent = parsed_hex.exponent;
-  int mantissa_width = 64 - base_internal::CountLeadingZeros64(mantissa);
+  auto mantissa_width = static_cast<unsigned>(bit_width(mantissa));
   const int shift = NormalizedShiftSize<FloatType>(mantissa_width, exponent);
   bool result_exact;
   exponent += shift;
diff --git a/absl/strings/charconv_test.cc b/absl/strings/charconv_test.cc
index 9090e9c8..b83de5a0 100644
--- a/absl/strings/charconv_test.cc
+++ b/absl/strings/charconv_test.cc
@@ -653,7 +653,9 @@ TEST(FromChars, NaNFloats) {
                      negative_from_chars_float);
     EXPECT_TRUE(std::signbit(negative_from_chars_float));
     EXPECT_FALSE(Identical(negative_from_chars_float, from_chars_float));
-    from_chars_float = std::copysign(from_chars_float, -1.0);
+    // Use the (float, float) overload of std::copysign to prevent narrowing;
+    // see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98251.
+    from_chars_float = std::copysign(from_chars_float, -1.0f);
     EXPECT_TRUE(Identical(negative_from_chars_float, from_chars_float));
   }
 }
diff --git a/absl/strings/internal/str_format/float_conversion.cc b/absl/strings/internal/str_format/float_conversion.cc
index 0ded0a66..2aa41aa7 100644
--- a/absl/strings/internal/str_format/float_conversion.cc
+++ b/absl/strings/internal/str_format/float_conversion.cc
@@ -24,10 +24,10 @@
 
 #include "absl/base/attributes.h"
 #include "absl/base/config.h"
-#include "absl/base/internal/bits.h"
 #include "absl/base/optimization.h"
 #include "absl/functional/function_ref.h"
 #include "absl/meta/type_traits.h"
+#include "absl/numeric/bits.h"
 #include "absl/numeric/int128.h"
 #include "absl/strings/numbers.h"
 #include "absl/types/optional.h"
@@ -315,12 +315,11 @@ class FractionalDigitGenerator {
 };
 
 // Count the number of leading zero bits.
-int LeadingZeros(uint64_t v) { return base_internal::CountLeadingZeros64(v); }
+int LeadingZeros(uint64_t v) { return countl_zero(v); }
 int LeadingZeros(uint128 v) {
   auto high = static_cast<uint64_t>(v >> 64);
   auto low = static_cast<uint64_t>(v);
-  return high != 0 ? base_internal::CountLeadingZeros64(high)
-                   : 64 + base_internal::CountLeadingZeros64(low);
+  return high != 0 ? countl_zero(high) : 64 + countl_zero(low);
 }
 
 // Round up the text digits starting at `p`.
diff --git a/absl/strings/numbers.cc b/absl/strings/numbers.cc
index 3da1059c..e6bf44ce 100644
--- a/absl/strings/numbers.cc
+++ b/absl/strings/numbers.cc
@@ -31,8 +31,8 @@
 #include <utility>
 
 #include "absl/base/attributes.h"
-#include "absl/base/internal/bits.h"
 #include "absl/base/internal/raw_logging.h"
+#include "absl/numeric/bits.h"
 #include "absl/strings/ascii.h"
 #include "absl/strings/charconv.h"
 #include "absl/strings/escaping.h"
@@ -303,7 +303,7 @@ static std::pair<uint64_t, uint64_t> Mul32(std::pair<uint64_t, uint64_t> num,
   uint64_t bits128_up = (bits96_127 >> 32) + (bits64_127 < bits64_95);
   if (bits128_up == 0) return {bits64_127, bits0_63};
 
-  int shift = 64 - base_internal::CountLeadingZeros64(bits128_up);
+  auto shift = static_cast<unsigned>(bit_width(bits128_up));
   uint64_t lo = (bits0_63 >> shift) + (bits64_127 << (64 - shift));
   uint64_t hi = (bits64_127 >> shift) + (bits128_up << (64 - shift));
   return {hi, lo};
@@ -334,7 +334,7 @@ static std::pair<uint64_t, uint64_t> PowFive(uint64_t num, int expfive) {
       5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5,
       5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5};
   result = Mul32(result, powers_of_five[expfive & 15]);
-  int shift = base_internal::CountLeadingZeros64(result.first);
+  int shift = countl_zero(result.first);
   if (shift != 0) {
     result.first = (result.first << shift) + (result.second >> (64 - shift));
     result.second = (result.second << shift);
diff --git a/absl/strings/numbers.h b/absl/strings/numbers.h
index 2e004b44..7966e250 100644
--- a/absl/strings/numbers.h
+++ b/absl/strings/numbers.h
@@ -37,7 +37,6 @@
 #include <type_traits>
 
 #include "absl/base/config.h"
-#include "absl/base/internal/bits.h"
 #ifdef __SSE4_2__
 // TODO(jorg): Remove this when we figure out the right way
 // to swap bytes on SSE 4.2 that works with the compilers
@@ -48,6 +47,7 @@
 #endif
 #include "absl/base/macros.h"
 #include "absl/base/port.h"
+#include "absl/numeric/bits.h"
 #include "absl/numeric/int128.h"
 #include "absl/strings/string_view.h"
 
@@ -240,7 +240,7 @@ inline size_t FastHexToBufferZeroPad16(uint64_t val, char* out) {
   }
 #endif
   // | 0x1 so that even 0 has 1 digit.
-  return 16 - absl::base_internal::CountLeadingZeros64(val | 0x1) / 4;
+  return 16 - countl_zero(val | 0x1) / 4;
 }
 
 }  // namespace numbers_internal