Export of internal Abseil changes

--
fcedaa5714efab8738446fa21620b827a40a3458 by Derek Mauro <dmauro@google.com>:

Uses Wyhash in the implementation of absl::Hash for hashing sequences
of more than 16 bytes on some platforms.

Due to the per-process randomization of the seed used by absl::Hash, users
should not notice this change, other than possibly getting better performance.

This change only affects platforms where absl::uint128 is implemented
with an intrinsic (and where sizeof(size_t)==8) since Wyhash relies on
fast 128-bit multiplication for speed.

PiperOrigin-RevId: 343956735

--
085e108c760084f19caa21dbeb2118de2be3f8f0 by Abseil Team <absl-team@google.com>:

Internal change for cord ring

PiperOrigin-RevId: 343919274

--
4c333278ad14d6692f203074b902506008ad624a by Jorg Brown <jorg@google.com>:

Minimize strings_internal::StringConstant further, by removing the need for the compiler to instantiate a compile-time class function.

PiperOrigin-RevId: 343878568

--
71c3c8c7b7821b67997e3d5345aaec67f93f266f by Abseil Team <absl-team@google.com>:

Internal change

PiperOrigin-RevId: 343838259
GitOrigin-RevId: fcedaa5714efab8738446fa21620b827a40a3458
Change-Id: Ifb91895a82d11e743acd42fe97ab7fb70712b7df

16 files changed, 800 insertions, 56 deletions

diff --git a/CMake/AbseilDll.cmake b/CMake/AbseilDll.cmake
index e0ff2492..8b664c24 100644
--- a/CMake/AbseilDll.cmake
+++ b/CMake/AbseilDll.cmake
@@ -122,6 +122,8 @@ set(ABSL_INTERNAL_DLL_FILES
   "hash/internal/hash.h"
   "hash/internal/hash.cc"
   "hash/internal/spy_hash_state.h"
+  "hash/internal/wyhash.h"
+  "hash/internal/wyhash.cc"
   "memory/memory.h"
   "meta/type_traits.h"
   "numeric/int128.cc"
diff --git a/absl/hash/BUILD.bazel b/absl/hash/BUILD.bazel
index 5b1e2d01..40c8f207 100644
--- a/absl/hash/BUILD.bazel
+++ b/absl/hash/BUILD.bazel
@@ -37,6 +37,7 @@ cc_library(
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
         ":city",
+        ":wyhash",
         "//absl/base:core_headers",
         "//absl/base:endian",
         "//absl/container:fixed_array",
@@ -120,3 +121,30 @@ cc_test(
         "@com_google_googletest//:gtest_main",
     ],
 )
+
+cc_library(
+    name = "wyhash",
+    srcs = ["internal/wyhash.cc"],
+    hdrs = ["internal/wyhash.h"],
+    copts = ABSL_DEFAULT_COPTS,
+    linkopts = ABSL_DEFAULT_LINKOPTS,
+    visibility = ["//visibility:private"],
+    deps = [
+        "//absl/base:config",
+        "//absl/base:endian",
+        "//absl/numeric:int128",
+    ],
+)
+
+cc_test(
+    name = "wyhash_test",
+    srcs = ["internal/wyhash_test.cc"],
+    copts = ABSL_TEST_COPTS,
+    linkopts = ABSL_DEFAULT_LINKOPTS,
+    visibility = ["//visibility:private"],
+    deps = [
+        ":wyhash",
+        "//absl/strings",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
diff --git a/absl/hash/CMakeLists.txt b/absl/hash/CMakeLists.txt
index 61365e9b..6d198775 100644
--- a/absl/hash/CMakeLists.txt
+++ b/absl/hash/CMakeLists.txt
@@ -24,7 +24,8 @@ absl_cc_library(
     "internal/hash.h"
   COPTS
     ${ABSL_DEFAULT_COPTS}
-  DEPS
+    DEPS
+    absl::city
     absl::core_headers
     absl::endian
     absl::fixed_array
@@ -34,7 +35,7 @@ absl_cc_library(
     absl::optional
     absl::variant
     absl::utility
-    absl::city
+    absl::wyhash
   PUBLIC
 )
 
@@ -114,3 +115,30 @@ absl_cc_test(
     gmock_main
 )
 
+absl_cc_library(
+  NAME
+    wyhash
+  HDRS
+    "internal/wyhash.h"
+  SRCS
+    "internal/wyhash.cc"
+  COPTS
+    ${ABSL_DEFAULT_COPTS}
+  DEPS
+    absl::config
+    absl::endian
+    absl::int128
+)
+
+absl_cc_test(
+  NAME
+    wyhash_test
+  SRCS
+    "internal/wyhash_test.cc"
+  COPTS
+    ${ABSL_TEST_COPTS}
+  DEPS
+    absl::wyhash
+    absl::strings
+    gmock_main
+)
diff --git a/absl/hash/internal/hash.cc b/absl/hash/internal/hash.cc
index b44ecb3a..1433eb9d 100644
--- a/absl/hash/internal/hash.cc
+++ b/absl/hash/internal/hash.cc
@@ -18,9 +18,9 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace hash_internal {
 
-uint64_t CityHashState::CombineLargeContiguousImpl32(uint64_t state,
-                                                     const unsigned char* first,
-                                                     size_t len) {
+uint64_t HashState::CombineLargeContiguousImpl32(uint64_t state,
+                                                 const unsigned char* first,
+                                                 size_t len) {
   while (len >= PiecewiseChunkSize()) {
     state =
         Mix(state, absl::hash_internal::CityHash32(reinterpret_cast<const char*>(first),
@@ -33,13 +33,11 @@ uint64_t CityHashState::CombineLargeContiguousImpl32(uint64_t state,
                                std::integral_constant<int, 4>{});
 }
 
-uint64_t CityHashState::CombineLargeContiguousImpl64(uint64_t state,
-                                                     const unsigned char* first,
-                                                     size_t len) {
+uint64_t HashState::CombineLargeContiguousImpl64(uint64_t state,
+                                                 const unsigned char* first,
+                                                 size_t len) {
   while (len >= PiecewiseChunkSize()) {
-    state =
-        Mix(state, absl::hash_internal::CityHash64(reinterpret_cast<const char*>(first),
-                                         PiecewiseChunkSize()));
+    state = Mix(state, Hash64(first, PiecewiseChunkSize()));
     len -= PiecewiseChunkSize();
     first += PiecewiseChunkSize();
   }
@@ -48,7 +46,24 @@ uint64_t CityHashState::CombineLargeContiguousImpl64(uint64_t state,
                                std::integral_constant<int, 8>{});
 }
 
-ABSL_CONST_INIT const void* const CityHashState::kSeed = &kSeed;
+ABSL_CONST_INIT const void* const HashState::kSeed = &kSeed;
+
+// The salt array used by Wyhash. This array is NOT the mechanism used to make
+// absl::Hash non-deterministic between program invocations.  See `Seed()` for
+// that mechanism.
+//
+// Any random values are fine. These values are just digits from the decimal
+// part of pi.
+// https://en.wikipedia.org/wiki/Nothing-up-my-sleeve_number
+constexpr uint64_t kWyhashSalt[5] = {
+    uint64_t{0x243F6A8885A308D3}, uint64_t{0x13198A2E03707344},
+    uint64_t{0xA4093822299F31D0}, uint64_t{0x082EFA98EC4E6C89},
+    uint64_t{0x452821E638D01377},
+};
+
+uint64_t HashState::WyhashImpl(const unsigned char* data, size_t len) {
+  return Wyhash(data, len, Seed(), kWyhashSalt);
+}
 
 }  // namespace hash_internal
 ABSL_NAMESPACE_END
diff --git a/absl/hash/internal/hash.h b/absl/hash/internal/hash.h
index b0132da2..eb3471d8 100644
--- a/absl/hash/internal/hash.h
+++ b/absl/hash/internal/hash.h
@@ -41,6 +41,7 @@
 #include "absl/base/internal/endian.h"
 #include "absl/base/port.h"
 #include "absl/container/fixed_array.h"
+#include "absl/hash/internal/wyhash.h"
 #include "absl/meta/type_traits.h"
 #include "absl/numeric/int128.h"
 #include "absl/strings/string_view.h"
@@ -712,9 +713,8 @@ template <typename T>
 struct is_hashable
     : std::integral_constant<bool, HashSelect::template Apply<T>::value> {};
 
-// CityHashState
-class ABSL_DLL CityHashState
-    : public HashStateBase<CityHashState> {
+// HashState
+class ABSL_DLL HashState : public HashStateBase<HashState> {
   // absl::uint128 is not an alias or a thin wrapper around the intrinsic.
   // We use the intrinsic when available to improve performance.
 #ifdef ABSL_HAVE_INTRINSIC_INT128
@@ -733,23 +733,22 @@ class ABSL_DLL CityHashState
 
  public:
   // Move only
-  CityHashState(CityHashState&&) = default;
-  CityHashState& operator=(CityHashState&&) = default;
+  HashState(HashState&&) = default;
+  HashState& operator=(HashState&&) = default;
 
-  // CityHashState::combine_contiguous()
+  // HashState::combine_contiguous()
   //
   // Fundamental base case for hash recursion: mixes the given range of bytes
   // into the hash state.
-  static CityHashState combine_contiguous(CityHashState hash_state,
-                                          const unsigned char* first,
-                                          size_t size) {
-    return CityHashState(
+  static HashState combine_contiguous(HashState hash_state,
+                                      const unsigned char* first, size_t size) {
+    return HashState(
         CombineContiguousImpl(hash_state.state_, first, size,
                               std::integral_constant<int, sizeof(size_t)>{}));
   }
-  using CityHashState::HashStateBase::combine_contiguous;
+  using HashState::HashStateBase::combine_contiguous;
 
-  // CityHashState::hash()
+  // HashState::hash()
   //
   // For performance reasons in non-opt mode, we specialize this for
   // integral types.
@@ -761,24 +760,24 @@ class ABSL_DLL CityHashState
     return static_cast<size_t>(Mix(Seed(), static_cast<uint64_t>(value)));
   }
 
-  // Overload of CityHashState::hash()
+  // Overload of HashState::hash()
   template <typename T, absl::enable_if_t<!IntegralFastPath<T>::value, int> = 0>
   static size_t hash(const T& value) {
-    return static_cast<size_t>(combine(CityHashState{}, value).state_);
+    return static_cast<size_t>(combine(HashState{}, value).state_);
   }
 
  private:
   // Invoked only once for a given argument; that plus the fact that this is
   // move-only ensures that there is only one non-moved-from object.
-  CityHashState() : state_(Seed()) {}
+  HashState() : state_(Seed()) {}
 
   // Workaround for MSVC bug.
   // We make the type copyable to fix the calling convention, even though we
   // never actually copy it. Keep it private to not affect the public API of the
   // type.
-  CityHashState(const CityHashState&) = default;
+  HashState(const HashState&) = default;
 
-  explicit CityHashState(uint64_t state) : state_(state) {}
+  explicit HashState(uint64_t state) : state_(state) {}
 
   // Implementation of the base case for combine_contiguous where we actually
   // mix the bytes into the state.
@@ -791,7 +790,8 @@ class ABSL_DLL CityHashState
   static uint64_t CombineContiguousImpl(uint64_t state,
                                         const unsigned char* first, size_t len,
                                         std::integral_constant<int, 8>
-                                        /* sizeof_size_t*/);
+                                        /* sizeof_size_t */);
+
 
   // Slow dispatch path for calls to CombineContiguousImpl with a size argument
   // larger than PiecewiseChunkSize().  Has the same effect as calling
@@ -838,6 +838,19 @@ class ABSL_DLL CityHashState
     return static_cast<uint64_t>(m ^ (m >> (sizeof(m) * 8 / 2)));
   }
 
+  // An extern to avoid bloat on a direct call to Wyhash() with fixed values for
+  // both the seed and salt parameters.
+  static uint64_t WyhashImpl(const unsigned char* data, size_t len);
+
+  ABSL_ATTRIBUTE_ALWAYS_INLINE static uint64_t Hash64(const unsigned char* data,
+                                                      size_t len) {
+#ifdef ABSL_HAVE_INTRINSIC_INT128
+    return WyhashImpl(data, len);
+#else
+    return absl::hash_internal::CityHash64(reinterpret_cast<const char*>(data), len);
+#endif
+  }
+
   // Seed()
   //
   // A non-deterministic seed.
@@ -869,8 +882,8 @@ class ABSL_DLL CityHashState
   uint64_t state_;
 };
 
-// CityHashState::CombineContiguousImpl()
-inline uint64_t CityHashState::CombineContiguousImpl(
+// HashState::CombineContiguousImpl()
+inline uint64_t HashState::CombineContiguousImpl(
     uint64_t state, const unsigned char* first, size_t len,
     std::integral_constant<int, 4> /* sizeof_size_t */) {
   // For large values we use CityHash, for small ones we just use a
@@ -892,18 +905,18 @@ inline uint64_t CityHashState::CombineContiguousImpl(
   return Mix(state, v);
 }
 
-// Overload of CityHashState::CombineContiguousImpl()
-inline uint64_t CityHashState::CombineContiguousImpl(
+// Overload of HashState::CombineContiguousImpl()
+inline uint64_t HashState::CombineContiguousImpl(
     uint64_t state, const unsigned char* first, size_t len,
     std::integral_constant<int, 8> /* sizeof_size_t */) {
-  // For large values we use CityHash, for small ones we just use a
-  // multiplicative hash.
+  // For large values we use Wyhash or CityHash depending on the platform, for
+  // small ones we just use a multiplicative hash.
   uint64_t v;
   if (len > 16) {
     if (ABSL_PREDICT_FALSE(len > PiecewiseChunkSize())) {
       return CombineLargeContiguousImpl64(state, first, len);
     }
-    v = absl::hash_internal::CityHash64(reinterpret_cast<const char*>(first), len);
+    v = Hash64(first, len);
   } else if (len > 8) {
     auto p = Read9To16(first, len);
     state = Mix(state, p.first);
@@ -934,7 +947,7 @@ struct PoisonedHash : private AggregateBarrier {
 
 template <typename T>
 struct HashImpl {
-  size_t operator()(const T& value) const { return CityHashState::hash(value); }
+  size_t operator()(const T& value) const { return HashState::hash(value); }
 };
 
 template <typename T>
diff --git a/absl/hash/internal/wyhash.cc b/absl/hash/internal/wyhash.cc
new file mode 100644
index 00000000..642bde43
--- /dev/null
+++ b/absl/hash/internal/wyhash.cc
@@ -0,0 +1,111 @@
+// Copyright 2020 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/hash/internal/wyhash.h"
+
+#include "absl/base/internal/unaligned_access.h"
+#include "absl/numeric/int128.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace hash_internal {
+
+static uint64_t WyhashMix(uint64_t v0, uint64_t v1) {
+  absl::uint128 p = v0;
+  p *= v1;
+  return absl::Uint128Low64(p) ^ absl::Uint128High64(p);
+}
+
+uint64_t Wyhash(const void* data, size_t len, uint64_t seed,
+                const uint64_t salt[]) {
+  const uint8_t* ptr = static_cast<const uint8_t*>(data);
+  uint64_t starting_length = static_cast<uint64_t>(len);
+  uint64_t current_state = seed ^ salt[0];
+
+  if (len > 64) {
+    // If we have more than 64 bytes, we're going to handle chunks of 64
+    // bytes at a time. We're going to build up two separate hash states
+    // which we will then hash together.
+    uint64_t duplicated_state = current_state;
+
+    do {
+      uint64_t a = absl::base_internal::UnalignedLoad64(ptr);
+      uint64_t b = absl::base_internal::UnalignedLoad64(ptr + 8);
+      uint64_t c = absl::base_internal::UnalignedLoad64(ptr + 16);
+      uint64_t d = absl::base_internal::UnalignedLoad64(ptr + 24);
+      uint64_t e = absl::base_internal::UnalignedLoad64(ptr + 32);
+      uint64_t f = absl::base_internal::UnalignedLoad64(ptr + 40);
+      uint64_t g = absl::base_internal::UnalignedLoad64(ptr + 48);
+      uint64_t h = absl::base_internal::UnalignedLoad64(ptr + 56);
+
+      uint64_t cs0 = WyhashMix(a ^ salt[1], b ^ current_state);
+      uint64_t cs1 = WyhashMix(c ^ salt[2], d ^ current_state);
+      current_state = (cs0 ^ cs1);
+
+      uint64_t ds0 = WyhashMix(e ^ salt[3], f ^ duplicated_state);
+      uint64_t ds1 = WyhashMix(g ^ salt[4], h ^ duplicated_state);
+      duplicated_state = (ds0 ^ ds1);
+
+      ptr += 64;
+      len -= 64;
+    } while (len > 64);
+
+    current_state = current_state ^ duplicated_state;
+  }
+
+  // We now have a data `ptr` with at most 64 bytes and the current state
+  // of the hashing state machine stored in current_state.
+  while (len > 16) {
+    uint64_t a = absl::base_internal::UnalignedLoad64(ptr);
+    uint64_t b = absl::base_internal::UnalignedLoad64(ptr + 8);
+
+    current_state = WyhashMix(a ^ salt[1], b ^ current_state);
+
+    ptr += 16;
+    len -= 16;
+  }
+
+  // We now have a data `ptr` with at most 16 bytes.
+  uint64_t a = 0;
+  uint64_t b = 0;
+  if (len > 8) {
+    // When we have at least 9 and at most 16 bytes, set A to the first 64
+    // bits of the input and B to the last 64 bits of the input. Yes, they will
+    // overlap in the middle if we are working with less than the full 16
+    // bytes.
+    a = absl::base_internal::UnalignedLoad64(ptr);
+    b = absl::base_internal::UnalignedLoad64(ptr + len - 8);
+  } else if (len > 3) {
+    // If we have at least 4 and at most 8 bytes, set A to the first 32
+    // bits and B to the last 32 bits.
+    a = absl::base_internal::UnalignedLoad32(ptr);
+    b = absl::base_internal::UnalignedLoad32(ptr + len - 4);
+  } else if (len > 0) {
+    // If we have at least 1 and at most 3 bytes, read all of the provided
+    // bits into A, with some adjustments.
+    a = ((ptr[0] << 16) | (ptr[len >> 1] << 8) | ptr[len - 1]);
+    b = 0;
+  } else {
+    a = 0;
+    b = 0;
+  }
+
+  uint64_t w = WyhashMix(a ^ salt[1], b ^ current_state);
+  uint64_t z = salt[1] ^ starting_length;
+  return WyhashMix(w, z);
+}
+
+}  // namespace hash_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
diff --git a/absl/hash/internal/wyhash.h b/absl/hash/internal/wyhash.h
new file mode 100644
index 00000000..4aff4e93
--- /dev/null
+++ b/absl/hash/internal/wyhash.h
@@ -0,0 +1,48 @@
+// Copyright 2020 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.
+//
+// This file provides the Google-internal implementation of the Wyhash
+// algorithm.
+//
+// Wyhash is a fast hash function for hash tables, the fastest we've currently
+// (late 2020) found that passes the SMHasher tests. The algorithm relies on
+// intrinsic 128-bit multiplication for speed. This is not meant to be secure -
+// just fast.
+
+#ifndef ABSL_HASH_INTERNAL_WYHASH_H_
+#define ABSL_HASH_INTERNAL_WYHASH_H_
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace hash_internal {
+
+// Hash function for a byte array. A 64-bit seed and a set of five 64-bit
+// integers are hashed into the result.
+//
+// To allow all hashable types (including string_view and Span) to depend on
+// this algoritm, we keep the API low-level, with as few dependencies as
+// possible.
+uint64_t Wyhash(const void* data, size_t len, uint64_t seed,
+                const uint64_t salt[5]);
+
+}  // namespace hash_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_HASH_INTERNAL_WYHASH_H_
diff --git a/absl/hash/internal/wyhash_test.cc b/absl/hash/internal/wyhash_test.cc
new file mode 100644
index 00000000..30dc9e34
--- /dev/null
+++ b/absl/hash/internal/wyhash_test.cc
@@ -0,0 +1,486 @@
+// Copyright 2020 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in cokSaltliance 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 ikSaltlied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/hash/internal/wyhash.h"
+
+#include "absl/strings/escaping.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace {
+
+static const uint64_t kCurrentSeed = 0;
+static const uint64_t kSalt[5] = {0xa0761d6478bd642f, 0xe7037ed1a0b428dbl,
+                                  0x8ebc6af09c88c6e3, 0x589965cc75374cc3l,
+                                  0x1d8e4e27c47d124f};
+
+// Note: We don't account for endianness, so the values here are only correct if
+// you're also running on a little endian platform.
+
+TEST(WyhashTest, EmptyString) {
+  const std::string s = "";
+  EXPECT_EQ(
+      absl::hash_internal::Wyhash(s.c_str(), s.length(), kCurrentSeed, kSalt),
+      4808886099364463827);
+}
+
+TEST(WyhashTest, Spaces) {
+  const std::string s = "   ";
+  EXPECT_EQ(
+      absl::hash_internal::Wyhash(s.c_str(), s.length(), kCurrentSeed, kSalt),
+      1686201463024549249);
+}
+
+TEST(WyhashTest, RepeatingString) {
+  const std::string s = "aaaa";
+  EXPECT_EQ(
+      absl::hash_internal::Wyhash(s.c_str(), s.length(), kCurrentSeed, kSalt),
+      6646112255271966632);
+}
+
+TEST(WyhashTest, HexString) {
+  const std::string small = "\x01\x02\x03";
+  const std::string med = "\x01\x02\x03\x04";
+
+  EXPECT_EQ(absl::hash_internal::Wyhash(small.c_str(), small.length(),
+                                        kCurrentSeed, kSalt),
+            11989428023081740911ULL);
+  EXPECT_EQ(absl::hash_internal::Wyhash(med.c_str(), med.length(), kCurrentSeed,
+                                        kSalt),
+            9765997711188871556ULL);
+}
+
+TEST(WyhashTest, Words) {
+  const std::string s = "third_party|wyhash|64";
+  EXPECT_EQ(
+      absl::hash_internal::Wyhash(s.c_str(), s.length(), kCurrentSeed, kSalt),
+      3702018632387611330);
+}
+
+TEST(WyhashTest, LongString) {
+  const std::string s =
+      "AbCdEfGhIjKlMnOpQrStUvWxYz0123456789AbCdEfGhIjKlMnOpQrStUvWxYz"
+      "0123456789AbCdEfGhIjKlMnOpQrStUvWxYz0123456789AbCdEfGhIjKlMnOp"
+      "QrStUvWxYz0123456789AbCdEfGhIjKlMnOpQrStUvWxYz0123456789AbCdEf"
+      "GhIjKlMnOpQrStUvWxYz0123456789AbCdEfGhIjKlMnOpQrStUvWxYz012345"
+      "6789AbCdEfGhIjKlMnOpQrStUvWxYz0123456789";
+
+  EXPECT_EQ(
+      absl::hash_internal::Wyhash(s.c_str(), s.length(), kCurrentSeed, kSalt),
+      9245411362605796064ULL);
+}
+
+TEST(WyhashTest, BigReference) {
+  struct ExpectedResult {
+    absl::string_view base64_data;
+    uint64_t seed;
+    uint64_t hash;
+  } expected_results[] = {
+      {"", uint64_t{0xec42b7ab404b8acb}, uint64_t{0xe5a40d39ab796423}},
+      {"Zw==", uint64_t{0xeeee074043a3ee0f}, uint64_t{0xa6564b468248c683}},
+      {"xmk=", uint64_t{0x857902089c393de}, uint64_t{0xef192f401b116e1c}},
+      {"c1H/", uint64_t{0x993df040024ca3af}, uint64_t{0xbe8dc0c54617639d}},
+      {"SuwpzQ==", uint64_t{0xc4e4c2acea740e96}, uint64_t{0x93d7f665b5521c8e}},
+      {"uqvy++M=", uint64_t{0x6a214b3db872d0cf}, uint64_t{0x646d70bb42445f28}},
+      {"RnzCVPgb", uint64_t{0x44343db6a89dba4d}, uint64_t{0x96a7b1e3cc9bd426}},
+      {"6OeNdlouYw==", uint64_t{0x77b5d6d1ae1dd483},
+       uint64_t{0x76020289ab0790c4}},
+      {"M5/JmmYyDbc=", uint64_t{0x89ab8ecb44d221f1},
+       uint64_t{0x39f842e4133b9b44}},
+      {"MVijWiVdBRdY", uint64_t{0x60244b17577ca81b},
+       uint64_t{0x2b8d7047be4bcaab}},
+      {"6V7Uq7LNxpu0VA==", uint64_t{0x59a08dcee0717067},
+       uint64_t{0x99628abef6716a97}},
+      {"EQ6CdEEhPdyHcOk=", uint64_t{0xf5f20db3ade57396},
+       uint64_t{0x4432e02ba42b2740}},
+      {"PqFB4fxnPgF+l+rc", uint64_t{0xbf8dee0751ad3efb},
+       uint64_t{0x74d810efcad7918a}},
+      {"a5aPOFwq7LA7+zKvPA==", uint64_t{0x6b7a06b268d63e30},
+       uint64_t{0x88c84e986002507f}},
+      {"VOwY21wCGv5D+/qqOvs=", uint64_t{0xb8c37f0ae0f54c82},
+       uint64_t{0x4f99acf193cf39b9}},
+      {"KdHmBTx8lHXYvmGJ+Vy7", uint64_t{0x9fcbed0c38e50eef},
+       uint64_t{0xd90e7a3655891e37}},
+      {"qJkPlbHr8bMF7/cA6aE65Q==", uint64_t{0x2af4bade1d8e3a1d},
+       uint64_t{0x3bb378b1d4df8fcf}},
+      {"ygvL0EhHZL0fIx6oHHtkxRQ=", uint64_t{0x714e3aa912da2f2c},
+       uint64_t{0xf78e94045c052d47}},
+      {"c1rFXkt5YztwZCQRngncqtSs", uint64_t{0xf5ee75e3cbb82c1c},
+       uint64_t{0x26da0b2130da6b40}},
+      {"8hsQrzszzeNQSEcVXLtvIhm6mw==", uint64_t{0x620e7007321b93b9},
+       uint64_t{0x30b4d426af8c6986}},
+      {"ffUL4RocfyP4KfikGxO1yk7omDI=", uint64_t{0xc08528cac2e551fc},
+       uint64_t{0x5413b4aaf3baaeae}},
+      {"OOB5TT00vF9Od/rLbAWshiErqhpV", uint64_t{0x6a1debf9cc3ad39},
+       uint64_t{0x756ab265370a1597}},
+      {"or5wtXM7BFzTNpSzr+Lw5J5PMhVJ/Q==", uint64_t{0x7e0a3c88111fc226},
+       uint64_t{0xdaf5f4b7d09814fb}},
+      {"gk6pCHDUsoopVEiaCrzVDhioRKxb844=", uint64_t{0x1301fef15df39edb},
+       uint64_t{0x8f874ae37742b75e}},
+      {"TNctmwlC5QbEM6/No4R/La3UdkfeMhzs", uint64_t{0x64e181f3d5817ab},
+       uint64_t{0x8fecd03956121ce8}},
+      {"SsQw9iAjhWz7sgcE9OwLuSC6hsM+BfHs2Q==", uint64_t{0xafafc44961078ecb},
+       uint64_t{0x229c292ea7a08285}},
+      {"ZzO3mVCj4xTT2TT3XqDyEKj2BZQBvrS8RHg=", uint64_t{0x4f7bb45549250094},
+       uint64_t{0xbb4bf0692d14bae}},
+      {"+klp5iPQGtppan5MflEls0iEUzqU+zGZkDJX", uint64_t{0xa30061abaa2818c},
+       uint64_t{0x207b24ca3bdac1db}},
+      {"RO6bvOnlJc8I9eniXlNgqtKy0IX6VNg16NRmgg==", uint64_t{0xd902ee3e44a5705f},
+       uint64_t{0x64f6cd6745d3825b}},
+      {"ZJjZqId1ZXBaij9igClE3nyliU5XWdNRrayGlYA=", uint64_t{0x316d36da516f583},
+       uint64_t{0xa2b2e1656b58df1e}},
+      {"7BfkhfGMDGbxfMB8uyL85GbaYQtjr2K8g7RpLzr/", uint64_t{0x402d83f9f834f616},
+       uint64_t{0xd01d30d9ee7a148}},
+      {"rycWk6wHH7htETQtje9PidS2YzXBx+Qkg2fY7ZYS7A==",
+       uint64_t{0x9c604164c016b72c}, uint64_t{0x1cb4cd00ab804e3b}},
+      {"RTkC2OUK+J13CdGllsH0H5WqgspsSa6QzRZouqx6pvI=",
+       uint64_t{0x3f4507e01f9e73ba}, uint64_t{0x4697f2637fd90999}},
+      {"tKjKmbLCNyrLCM9hycOAXm4DKNpM12oZ7dLTmUx5iwAi",
+       uint64_t{0xc3fe0d5be8d2c7c7}, uint64_t{0x8383a756b5688c07}},
+      {"VprUGNH+5NnNRaORxgH/ySrZFQFDL+4VAodhfBNinmn8cg==",
+       uint64_t{0x531858a40bfa7ea1}, uint64_t{0x695c29cb3696a975}},
+      {"gc1xZaY+q0nPcUvOOnWnT3bqfmT/geth/f7Dm2e/DemMfk4=",
+       uint64_t{0x86689478a7a7e8fa}, uint64_t{0xda2e5a5a5e971521}},
+      {"Mr35fIxqx1ukPAL0su1yFuzzAU3wABCLZ8+ZUFsXn47UmAph",
+       uint64_t{0x4ec948b8e7f27288}, uint64_t{0x7935d4befa056b2b}},
+      {"A9G8pw2+m7+rDtWYAdbl8tb2fT7FFo4hLi2vAsa5Y8mKH3CX3g==",
+       uint64_t{0xce46c7213c10032}, uint64_t{0x38dd541ca95420fe}},
+      {"DFaJGishGwEHDdj9ixbCoaTjz9KS0phLNWHVVdFsM93CvPft3hM=",
+       uint64_t{0xf63e96ee6f32a8b6}, uint64_t{0xcc06c7a4963f967f}},
+      {"7+Ugx+Kr3aRNgYgcUxru62YkTDt5Hqis+2po81hGBkcrJg4N0uuy",
+       uint64_t{0x1cfe85e65fc5225}, uint64_t{0xbf0f6f66e232fb20}},
+      {"H2w6O8BUKqu6Tvj2xxaecxEI2wRgIgqnTTG1WwOgDSINR13Nm4d4Vg==",
+       uint64_t{0x45c474f1cee1d2e8}, uint64_t{0xf7efb32d373fe71a}},
+      {"1XBMnIbqD5jy65xTDaf6WtiwtdtQwv1dCVoqpeKj+7cTR1SaMWMyI04=",
+       uint64_t{0x6e024e14015f329c}, uint64_t{0xe2e64634b1c12660}},
+      {"znZbdXG2TSFrKHEuJc83gPncYpzXGbAebUpP0XxzH0rpe8BaMQ17nDbt",
+       uint64_t{0x760c40502103ae1c}, uint64_t{0x285b8fd1638e306d}},
+      {"ylu8Atu13j1StlcC1MRMJJXIl7USgDDS22HgVv0WQ8hx/8pNtaiKB17hCQ==",
+       uint64_t{0x17fd05c3c560c320}, uint64_t{0x658e8a4e3b714d6c}},
+      {"M6ZVVzsd7vAvbiACSYHioH/440dp4xG2mLlBnxgiqEvI/aIEGpD0Sf4VS0g=",
+       uint64_t{0x8b34200a6f8e90d9}, uint64_t{0xf391fb968e0eb398}},
+      {"li3oFSXLXI+ubUVGJ4blP6mNinGKLHWkvGruun85AhVn6iuMtocbZPVhqxzn",
+       uint64_t{0x6be89e50818bdf69}, uint64_t{0x744a9ea0cc144bf2}},
+      {"kFuQHuUCqBF3Tc3hO4dgdIp223ShaCoog48d5Do5zMqUXOh5XpGK1t5XtxnfGA==",
+       uint64_t{0xfb389773315b47d8}, uint64_t{0x12636f2be11012f1}},
+      {"jWmOad0v0QhXVJd1OdGuBZtDYYS8wBVHlvOeTQx9ZZnm8wLEItPMeihj72E0nWY=",
+       uint64_t{0x4f2512a23f61efee}, uint64_t{0x29c57de825948f80}},
+      {"z+DHU52HaOQdW4JrZwDQAebEA6rm13Zg/9lPYA3txt3NjTBqFZlOMvTRnVzRbl23",
+       uint64_t{0x59ccd92fc16c6fda}, uint64_t{0x58c6f99ab0d1c021}},
+      {"MmBiGDfYeTayyJa/tVycg+rN7f9mPDFaDc+23j0TlW9094er0ADigsl4QX7V3gG/qw==",
+       uint64_t{0x25c5a7f5bd330919}, uint64_t{0x13e7b5a7b82fe3bb}},
+      {"774RK+9rOL4iFvs1q2qpo/JVc/I39buvNjqEFDtDvyoB0FXxPI2vXqOrk08VPfIHkmU=",
+       uint64_t{0x51df4174d34c97d7}, uint64_t{0x10fbc87901e02b63}},
+      {"+slatXiQ7/2lK0BkVUI1qzNxOOLP3I1iK6OfHaoxgqT63FpzbElwEXSwdsryq3UlHK0I",
+       uint64_t{0x80ce6d76f89cb57}, uint64_t{0xa24c9184901b748b}},
+      {"64mVTbQ47dHjHlOHGS/hjJwr/"
+       "K2frCNpn87exOqMzNUVYiPKmhCbfS7vBUce5tO6Ec9osQ==",
+       uint64_t{0x20961c911965f684}, uint64_t{0xcac4fd4c5080e581}},
+      {"fIsaG1r530SFrBqaDj1kqE0AJnvvK8MNEZbII2Yw1OK77v0V59xabIh0B5axaz/"
+       "+a2V5WpA=",
+       uint64_t{0x4e5b926ec83868e7}, uint64_t{0xc38bdb7483ba68e1}},
+      {"PGih0zDEOWCYGxuHGDFu9Ivbff/"
+       "iE7BNUq65tycTR2R76TerrXALRosnzaNYO5fjFhTi+CiS",
+       uint64_t{0x3927b30b922eecef}, uint64_t{0xdb2a8069b2ceaffa}},
+      {"RnpA/"
+       "zJnEnnLjmICORByRVb9bCOgxF44p3VMiW10G7PvW7IhwsWajlP9kIwNA9FjAD2GoQHk2Q="
+       "=",
+       uint64_t{0xbd0291284a49b61c}, uint64_t{0xdf9fe91d0d1c7887}},
+      {"qFklMceaTHqJpy2qavJE+EVBiNFOi6OxjOA3LeIcBop1K7w8xQi3TrDk+"
+       "BrWPRIbfprszSaPfrI=",
+       uint64_t{0x73a77c575bcc956}, uint64_t{0xe83f49e96e2e6a08}},
+      {"cLbfUtLl3EcQmITWoTskUR8da/VafRDYF/ylPYwk7/"
+       "zazk6ssyrzxMN3mmSyvrXR2yDGNZ3WDrTT",
+       uint64_t{0x766a0e2ade6d09a6}, uint64_t{0xc69e61b62ca2b62}},
+      {"s/"
+       "Jf1+"
+       "FbsbCpXWPTUSeWyMH6e4CvTFvPE5Fs6Z8hvFITGyr0dtukHzkI84oviVLxhM1xMxrMAy1db"
+       "w==",
+       uint64_t{0x2599f4f905115869}, uint64_t{0xb4a4f3f85f8298fe}},
+      {"FvyQ00+j7nmYZVQ8hI1Edxd0AWplhTfWuFGiu34AK5X8u2hLX1bE97sZM0CmeLe+"
+       "7LgoUT1fJ/axybE=",
+       uint64_t{0xd8256e5444d21e53}, uint64_t{0x167a1b39e1e95f41}},
+      {"L8ncxMaYLBH3g9buPu8hfpWZNlOF7nvWLNv9IozH07uQsIBWSKxoPy8+"
+       "LW4tTuzC6CIWbRGRRD1sQV/4",
+       uint64_t{0xf664a91333fb8dfd}, uint64_t{0xf8a2a5649855ee41}},
+      {"CDK0meI07yrgV2kQlZZ+"
+       "wuVqhc2NmzqeLH7bmcA6kchsRWFPeVF5Wqjjaj556ABeUoUr3yBmfU3kWOakkg==",
+       uint64_t{0x9625b859be372cd1}, uint64_t{0x27992565b595c498}},
+      {"d23/vc5ONh/"
+       "HkMiq+gYk4gaCNYyuFKwUkvn46t+dfVcKfBTYykr4kdvAPNXGYLjM4u1YkAEFpJP+"
+       "nX7eOvs=",
+       uint64_t{0x7b99940782e29898}, uint64_t{0x3e08cca5b71f9346}},
+      {"NUR3SRxBkxTSbtQORJpu/GdR6b/h6sSGfsMj/KFd99ahbh+9r7LSgSGmkGVB/"
+       "mGoT0pnMTQst7Lv2q6QN6Vm",
+       uint64_t{0x4fe12fa5383b51a8}, uint64_t{0xad406b10c770a6d2}},
+      {"2BOFlcI3Z0RYDtS9T9Ie9yJoXlOdigpPeeT+CRujb/"
+       "O39Ih5LPC9hP6RQk1kYESGyaLZZi3jtabHs7DiVx/VDg==",
+       uint64_t{0xe2ccb09ac0f5b4b6}, uint64_t{0xd1713ce6e552bcf2}},
+      {"FF2HQE1FxEvWBpg6Z9zAMH+Zlqx8S1JD/"
+       "wIlViL6ZDZY63alMDrxB0GJQahmAtjlm26RGLnjW7jmgQ4Ie3I+014=",
+       uint64_t{0x7d0a37adbd7b753b}, uint64_t{0x753b287194c73ad3}},
+      {"tHmO7mqVL/PX11nZrz50Hc+M17Poj5lpnqHkEN+4bpMx/"
+       "YGbkrGOaYjoQjgmt1X2QyypK7xClFrjeWrCMdlVYtbW",
+       uint64_t{0xd3ae96ef9f7185f2}, uint64_t{0x5ae41a95f600af1c}},
+      {"/WiHi9IQcxRImsudkA/KOTqGe8/"
+       "gXkhKIHkjddv5S9hi02M049dIK3EUyAEjkjpdGLUs+BN0QzPtZqjIYPOgwsYE9g==",
+       uint64_t{0x4fb88ea63f79a0d8}, uint64_t{0x4a61163b86a8bb4c}},
+      {"qds+1ExSnU11L4fTSDz/QE90g4Jh6ioqSh3KDOTOAo2pQGL1k/"
+       "9CCC7J23YF27dUTzrWsCQA2m4epXoCc3yPHb3xElA=",
+       uint64_t{0xed564e259bb5ebe9}, uint64_t{0x42eeaa79e760c7e4}},
+      {"8FVYHx40lSQPTHheh08Oq0/"
+       "pGm2OlG8BEf8ezvAxHuGGdgCkqpXIueJBF2mQJhTfDy5NncO8ntS7vaKs7sCNdDaNGOEi",
+       uint64_t{0x3e3256b60c428000}, uint64_t{0x698df622ef465b0a}},
+      {"4ZoEIrJtstiCkeew3oRzmyJHVt/pAs2pj0HgHFrBPztbQ10NsQ/"
+       "lM6DM439QVxpznnBSiHMgMQJhER+70l72LqFTO1JiIQ==",
+       uint64_t{0xfb05bad59ec8705}, uint64_t{0x157583111e1a6026}},
+      {"hQPtaYI+wJyxXgwD5n8jGIKFKaFA/"
+       "P83KqCKZfPthnjwdOFysqEOYwAaZuaaiv4cDyi9TyS8hk5cEbNP/jrI7q6pYGBLbsM=",
+       uint64_t{0xafdc251dbf97b5f8}, uint64_t{0xaa1388f078e793e0}},
+      {"S4gpMSKzMD7CWPsSfLeYyhSpfWOntyuVZdX1xSBjiGvsspwOZcxNKCRIOqAA0moUfOh3I5+"
+       "juQV4rsqYElMD/gWfDGpsWZKQ",
+       uint64_t{0x10ec9c92ddb5dcbc}, uint64_t{0xf10d68d0f3309360}},
+      {"oswxop+"
+       "bthuDLT4j0PcoSKby4LhF47ZKg8K17xxHf74UsGCzTBbOz0MM8hQEGlyqDT1iUiAYnaPaUp"
+       "L2mRK0rcIUYA4qLt5uOw==",
+       uint64_t{0x9a767d5822c7dac4}, uint64_t{0x2af056184457a3de}},
+      {"0II/"
+       "697p+"
+       "BtLSjxj5989OXI004TogEb94VUnDzOVSgMXie72cuYRvTFNIBgtXlKfkiUjeqVpd4a+"
+       "n5bxNOD1TGrjQtzKU5r7obo=",
+       uint64_t{0xee46254080d6e2db}, uint64_t{0x6d0058e1590b2489}},
+      {"E84YZW2qipAlMPmctrg7TKlwLZ68l4L+c0xRDUfyyFrA4MAti0q9sHq3TDFviH0Y+"
+       "Kq3tEE5srWFA8LM9oomtmvm5PYxoaarWPLc",
+       uint64_t{0xbbb669588d8bf398}, uint64_t{0x638f287f68817f12}},
+      {"x3pa4HIElyZG0Nj7Vdy9IdJIR4izLmypXw5PCmZB5y68QQ4uRaVVi3UthsoJROvbjDJkP2D"
+       "Q6L/eN8pFeLFzNPKBYzcmuMOb5Ull7w==",
+       uint64_t{0xdc2afaa529beef44}, uint64_t{0xc46b71fecefd5467}},
+      {"jVDKGYIuWOP/"
+       "QKLdd2wi8B2VJA8Wh0c8PwrXJVM8FOGM3voPDVPyDJOU6QsBDPseoR8uuKd19OZ/"
+       "zAvSCB+zlf6upAsBlheUKgCfKww=",
+       uint64_t{0xf1f67391d45013a8}, uint64_t{0x2c8e94679d964e0a}},
+      {"mkquunhmYe1aR2wmUz4vcvLEcKBoe6H+kjUok9VUn2+eTSkWs4oDDtJvNCWtY5efJwg/"
+       "j4PgjRYWtqnrCkhaqJaEvkkOwVfgMIwF3e+d",
+       uint64_t{0x16fce2b8c65a3429}, uint64_t{0x8612b797ce22503a}},
+      {"fRelvKYonTQ+s+rnnvQw+JzGfFoPixtna0vzcSjiDqX5s2Kg2//"
+       "UGrK+AVCyMUhO98WoB1DDbrsOYSw2QzrcPe0+3ck9sePvb+Q/IRaHbw==",
+       uint64_t{0xf4b096699f49fe67}, uint64_t{0x59f929babfba7170}},
+      {"DUwXFJzagljo44QeJ7/"
+       "6ZKw4QXV18lhkYT2jglMr8WB3CHUU4vdsytvw6AKv42ZcG6fRkZkq9fpnmXy6xG0aO3WPT1"
+       "eHuyFirAlkW+zKtwg=",
+       uint64_t{0xca584c4bc8198682}, uint64_t{0x9527556923fb49a0}},
+      {"cYmZCrOOBBongNTr7e4nYn52uQUy2mfe48s50JXx2AZ6cRAt/"
+       "xRHJ5QbEoEJOeOHsJyM4nbzwFm++SlT6gFZZHJpkXJ92JkR86uS/eV1hJUR",
+       uint64_t{0xed269fc3818b6aad}, uint64_t{0x1039ab644f5e150b}},
+      {"EXeHBDfhwzAKFhsMcH9+2RHwV+mJaN01+9oacF6vgm8mCXRd6jeN9U2oAb0of5c5cO4i+"
+       "Vb/LlHZSMI490SnHU0bejhSCC2gsC5d2K30ER3iNA==",
+       uint64_t{0x33f253cbb8fe66a8}, uint64_t{0x7816c83f3aa05e6d}},
+      {"FzkzRYoNjkxFhZDso94IHRZaJUP61nFYrh5MwDwv9FNoJ5jyNCY/"
+       "eazPZk+tbmzDyJIGw2h3GxaWZ9bSlsol/vK98SbkMKCQ/wbfrXRLcDzdd/8=",
+       uint64_t{0xd0b76b2c1523d99c}, uint64_t{0xf51d2f564518c619}},
+      {"Re4aXISCMlYY/XsX7zkIFR04ta03u4zkL9dVbLXMa/q6hlY/CImVIIYRN3VKP4pnd0AUr/"
+       "ugkyt36JcstAInb4h9rpAGQ7GMVOgBniiMBZ/MGU7H",
+       uint64_t{0xfd28f0811a2a237f}, uint64_t{0x67d494cff03ac004}},
+      {"ueLyMcqJXX+MhO4UApylCN9WlTQ+"
+       "ltJmItgG7vFUtqs2qNwBMjmAvr5u0sAKd8jpzV0dDPTwchbIeAW5zbtkA2NABJV6hFM48ib"
+       "4/J3A5mseA3cS8w==",
+       uint64_t{0x6261fb136482e84}, uint64_t{0x2802d636ced1cfbb}},
+      {"6Si7Yi11L+jZMkwaN+GUuzXMrlvEqviEkGOilNq0h8TdQyYKuFXzkYc/"
+       "q74gP3pVCyiwz9KpVGMM9vfnq36riMHRknkmhQutxLZs5fbmOgEO69HglCU=",
+       uint64_t{0x458efc750bca7c3a}, uint64_t{0xf64e20bad771cb12}},
+      {"Q6AbOofGuTJOegPh9Clm/"
+       "9crtUMQqylKrTc1fhfJo1tqvpXxhU4k08kntL1RG7woRnFrVh2UoMrL1kjin+s9CanT+"
+       "y4hHwLqRranl9FjvxfVKm3yvg68",
+       uint64_t{0xa7e69ff84e5e7c27}, uint64_t{0xb9a6cf84a83e15e}},
+      {"ieQEbIPvqY2YfIjHnqfJiO1/MIVRk0RoaG/WWi3kFrfIGiNLCczYoklgaecHMm/"
+       "1sZ96AjO+a5stQfZbJQwS7Sc1ODABEdJKcTsxeW2hbh9A6CFzpowP1A==",
+       uint64_t{0x3c59bfd0c29efe9e}, uint64_t{0x8da6630319609301}},
+      {"zQUv8hFB3zh2GGl3KTvCmnfzE+"
+       "SUgQPVaSVIELFX5H9cE3FuVFGmymkPQZJLAyzC90Cmi8GqYCvPqTuAAB//"
+       "XTJxy4bCcVArgZG9zJXpjowpNBfr3ngWrSE=",
+       uint64_t{0x10befacc6afd298d}, uint64_t{0x40946a86e2a996f3}},
+      {"US4hcC1+op5JKGC7eIs8CUgInjKWKlvKQkapulxW262E/"
+       "B2ye79QxOexf188u2mFwwe3WTISJHRZzS61IwljqAWAWoBAqkUnW8SHmIDwHUP31J0p5sGd"
+       "P47L",
+       uint64_t{0x41d5320b0a38efa7}, uint64_t{0xcab7f5997953fa76}},
+      {"9bHUWFna2LNaGF6fQLlkx1Hkt24nrkLE2CmFdWgTQV3FFbUe747SSqYw6ebpTa07MWSpWRP"
+       "sHesVo2B9tqHbe7eQmqYebPDFnNqrhSdZwFm9arLQVs+7a3Ic6A==",
+       uint64_t{0x58db1c7450fe17f3}, uint64_t{0x39129ca0e04fc465}},
+      {"Kb3DpHRUPhtyqgs3RuXjzA08jGb59hjKTOeFt1qhoINfYyfTt2buKhD6YVffRCPsgK9SeqZ"
+       "qRPJSyaqsa0ovyq1WnWW8jI/NhvAkZTVHUrX2pC+cD3OPYT05Dag=",
+       uint64_t{0x6098c055a335b7a6}, uint64_t{0x5238221fd685e1b8}},
+      {"gzxyMJIPlU+bJBwhFUCHSofZ/"
+       "319LxqMoqnt3+L6h2U2+ZXJCSsYpE80xmR0Ta77Jq54o92SMH87HV8dGOaCTuAYF+"
+       "lDL42SY1P316Cl0sZTS2ow3ZqwGbcPNs/1",
+       uint64_t{0x1bbacec67845a801}, uint64_t{0x175130c407dbcaab}},
+      {"uR7V0TW+FGVMpsifnaBAQ3IGlr1wx5sKd7TChuqRe6OvUXTlD4hKWy8S+"
+       "8yyOw8lQabism19vOQxfmocEOW/"
+       "vzY0pEa87qHrAZy4s9fH2Bltu8vaOIe+agYohhYORQ==",
+       uint64_t{0xc419cfc7442190}, uint64_t{0x2f20e7536c0b0df}},
+      {"1UR5eoo2aCwhacjZHaCh9bkOsITp6QunUxHQ2SfeHv0imHetzt/"
+       "Z70mhyWZBalv6eAx+YfWKCUib2SHDtz/"
+       "A2dc3hqUWX5VfAV7FQsghPUAtu6IiRatq4YSLpDvKZBQ=",
+       uint64_t{0xc95e510d94ba270c}, uint64_t{0x2742cb488a04ad56}},
+      {"opubR7H63BH7OtY+Avd7QyQ25UZ8kLBdFDsBTwZlY6gA/"
+       "u+x+"
+       "czC9AaZMgmQrUy15DH7YMGsvdXnviTtI4eVI4aF1H9Rl3NXMKZgwFOsdTfdcZeeHVRzBBKX"
+       "8jUfh1il",
+       uint64_t{0xff1ae05c98089c3f}, uint64_t{0xd6afb593879ff93b}},
+      {"DC0kXcSXtfQ9FbSRwirIn5tgPri0sbzHSa78aDZVDUKCMaBGyFU6BmrulywYX8yzvwprdLs"
+       "oOwTWN2wMjHlPDqrvVHNEjnmufRDblW+nSS+xtKNs3N5xsxXdv6JXDrAB/Q==",
+       uint64_t{0x90c02b8dceced493}, uint64_t{0xf50ad64caac0ca7f}},
+      {"BXRBk+3wEP3Lpm1y75wjoz+PgB0AMzLe8tQ1AYU2/"
+       "oqrQB2YMC6W+9QDbcOfkGbeH+b7IBkt/"
+       "gwCMw2HaQsRFEsurXtcQ3YwRuPz5XNaw5NAvrNa67Fm7eRzdE1+hWLKtA8=",
+       uint64_t{0x9f8a76697ab1aa36}, uint64_t{0x2ade95c4261364ae}},
+      {"RRBSvEGYnzR9E45Aps/+WSnpCo/X7gJLO4DRnUqFrJCV/kzWlusLE/"
+       "6ZU6RoUf2ROwcgEvUiXTGjLs7ts3t9SXnJHxC1KiOzxHdYLMhVvgNd3hVSAXODpKFSkVXND"
+       "55G2L1W",
+       uint64_t{0x6ba1bf3d811a531d}, uint64_t{0x5c4f3299faacd07a}},
+      {"jeh6Qazxmdi57pa9S3XSnnZFIRrnc6s8QLrah5OX3SB/V2ErSPoEAumavzQPkdKF1/"
+       "SfvmdL+qgF1C+Yawy562QaFqwVGq7+tW0yxP8FStb56ZRgNI4IOmI30s1Ei7iops9Uuw==",
+       uint64_t{0x6a418974109c67b4}, uint64_t{0xfffe3bff0ae5e9bc}},
+      {"6QO5nnDrY2/"
+       "wrUXpltlKy2dSBcmK15fOY092CR7KxAjNfaY+"
+       "aAmtWbbzQk3MjBg03x39afSUN1fkrWACdyQKRaGxgwq6MGNxI6W+8DLWJBHzIXrntrE/"
+       "ml6fnNXEpxplWJ1vEs4=",
+       uint64_t{0x8472f1c2b3d230a3}, uint64_t{0x1db785c0005166e4}},
+      {"0oPxeEHhqhcFuwonNfLd5jF3RNATGZS6NPoS0WklnzyokbTqcl4BeBkMn07+fDQv83j/"
+       "BpGUwcWO05f3+DYzocfnizpFjLJemFGsls3gxcBYxcbqWYev51tG3lN9EvRE+X9+Pwww",
+       uint64_t{0x5e06068f884e73a7}, uint64_t{0xea000d962ad18418}},
+      {"naSBSjtOKgAOg8XVbR5cHAW3Y+QL4Pb/JO9/"
+       "oy6L08wvVRZqo0BrssMwhzBP401Um7A4ppAupbQeJFdMrysY34AuSSNvtNUy5VxjNECwiNt"
+       "gwYHw7yakDUv8WvonctmnoSPKENegQg==",
+       uint64_t{0x55290b1a8f170f59}, uint64_t{0xe42aef38359362d9}},
+      {"vPyl8DxVeRe1OpilKb9KNwpGkQRtA94UpAHetNh+"
+       "95V7nIW38v7PpzhnTWIml5kw3So1Si0TXtIUPIbsu32BNhoH7QwFvLM+"
+       "JACgSpc5e3RjsL6Qwxxi11npwxRmRUqATDeMUfRAjxg=",
+       uint64_t{0x5501cfd83dfe706a}, uint64_t{0xc8e95657348a3891}},
+      {"QC9i2GjdTMuNC1xQJ74ngKfrlA4w3o58FhvNCltdIpuMhHP1YsDA78scQPLbZ3OCUgeQguY"
+       "f/vw6zAaVKSgwtaykqg5ka/4vhz4hYqWU5ficdXqClHl+zkWEY26slCNYOM5nnDlly8Cj",
+       uint64_t{0xe43ed13d13a66990}, uint64_t{0xc162eca864f238c6}},
+      {"7CNIgQhAHX27nxI0HeB5oUTnTdgKpRDYDKwRcXfSFGP1XeT9nQF6WKCMjL1tBV6x7KuJ91G"
+       "Zz11F4c+8s+MfqEAEpd4FHzamrMNjGcjCyrVtU6y+7HscMVzr7Q/"
+       "ODLcPEFztFnwjvCjmHw==",
+       uint64_t{0xdf43bc375cf5283f}, uint64_t{0xbe1fb373e20579ad}},
+      {"Qa/hC2RPXhANSospe+gUaPfjdK/yhQvfm4cCV6/pdvCYWPv8p1kMtKOX3h5/"
+       "8oZ31fsmx4Axphu5qXJokuhZKkBUJueuMpxRyXpwSWz2wELx5glxF7CM0Fn+"
+       "OevnkhUn5jsPlG2r5jYlVn8=",
+       uint64_t{0x8112b806d288d7b5}, uint64_t{0x628a1d4f40aa6ffd}},
+      {"kUw/0z4l3a89jTwN5jpG0SHY5km/"
+       "IVhTjgM5xCiPRLncg40aqWrJ5vcF891AOq5hEpSq0bUCJUMFXgct7kvnys905HjerV7Vs1G"
+       "y84tgVJ70/2+pAZTsB/PzNOE/G6sOj4+GbTzkQu819OLB",
+       uint64_t{0xd52a18abb001cb46}, uint64_t{0xa87bdb7456340f90}},
+      {"VDdfSDbO8Tdj3T5W0XM3EI7iHh5xpIutiM6dvcJ/fhe23V/srFEkDy5iZf/"
+       "VnA9kfi2C79ENnFnbOReeuZW1b3MUXB9lgC6U4pOTuC+"
+       "jHK3Qnpyiqzj7h3ISJSuo2pob7vY6VHZo6Fn7exEqHg==",
+       uint64_t{0xe12b76a2433a1236}, uint64_t{0x5960ef3ba982c801}},
+      {"Ldfvy3ORdquM/R2fIkhH/ONi69mcP1AEJ6n/"
+       "oropwecAsLJzQSgezSY8bEiEs0VnFTBBsW+RtZY6tDj03fnb3amNUOq1b7jbqyQkL9hpl+"
+       "2Z2J8IaVSeownWl+bQcsR5/xRktIMckC5AtF4YHfU=",
+       uint64_t{0x175bf7319cf1fa00}, uint64_t{0x5026586df9a431ec}},
+      {"BrbNpb42+"
+       "VzZAjJw6QLirXzhweCVRfwlczzZ0VX2xluskwBqyfnGovz5EuX79JJ31VNXa5hTkAyQat3l"
+       "YKRADTdAdwE5PqM1N7YaMqqsqoAAAeuYVXuk5eWCykYmClNdSspegwgCuT+403JigBzi",
+       uint64_t{0xd63d57b3f67525ae}, uint64_t{0xfe4b8a20fdf0840b}},
+      {"gB3NGHJJvVcuPyF0ZSvHwnWSIfmaI7La24VMPQVoIIWF7Z74NltPZZpx2f+cocESM+"
+       "ILzQW9p+BC8x5IWz7N4Str2WLGKMdgmaBfNkEhSHQDU0IJEOnpUt0HmjhFaBlx0/"
+       "LTmhua+rQ6Wup8ezLwfg==",
+       uint64_t{0x933faea858832b73}, uint64_t{0xdcb761867da7072f}},
+      {"hTKHlRxx6Pl4gjG+6ksvvj0CWFicUg3WrPdSJypDpq91LUWRni2KF6+"
+       "81ZoHBFhEBrCdogKqeK+hy9bLDnx7g6rAFUjtn1+cWzQ2YjiOpz4+"
+       "ROBB7lnwjyTGWzJD1rXtlso1g2qVH8XJVigC5M9AIxM=",
+       uint64_t{0x53d061e5f8e7c04f}, uint64_t{0xc10d4653667275b7}},
+      {"IWQBelSQnhrr0F3BhUpXUIDauhX6f95Qp+A0diFXiUK7irwPG1oqBiqHyK/SH/"
+       "9S+"
+       "rln9DlFROAmeFdH0OCJi2tFm4afxYzJTFR4HnR4cG4x12JqHaZLQx6iiu6CE3rtWBVz99oA"
+       "wCZUOEXIsLU24o2Y",
+       uint64_t{0xdb4124556dd515e0}, uint64_t{0x727720deec13110b}},
+      {"TKo+l+"
+       "1dOXdLvIrFqeLaHdm0HZnbcdEgOoLVcGRiCbAMR0j5pIFw8D36tefckAS1RCFOH5IgP8yiF"
+       "T0Gd0a2hI3+"
+       "fTKA7iK96NekxWeoeqzJyctc6QsoiyBlkZerRxs5RplrxoeNg29kKDTM0K94mnhD9g==",
+       uint64_t{0x4fb31a0dd681ee71}, uint64_t{0x710b009662858dc9}},
+      {"YU4e7G6EfQYvxCFoCrrT0EFgVLHFfOWRTJQJ5gxM3G2b+"
+       "1kJf9YPrpsxF6Xr6nYtS8reEEbDoZJYqnlk9lXSkVArm88Cqn6d25VCx3+"
+       "49MqC0trIlXtb7SXUUhwpJK16T0hJUfPH7s5cMZXc6YmmbFuBNPE=",
+       uint64_t{0x27cc72eefa138e4c}, uint64_t{0xfbf8f7a3ecac1eb7}},
+      {"/I/"
+       "eImMwPo1U6wekNFD1Jxjk9XQVi1D+"
+       "FPdqcHifYXQuP5aScNQfxMAmaPR2XhuOQhADV5tTVbBKwCDCX4E3jcDNHzCiPvViZF1W27t"
+       "xaf2BbFQdwKrNCmrtzcluBFYu0XZfc7RU1RmxK/RtnF1qHsq/O4pp",
+       uint64_t{0x44bc2dfba4bd3ced}, uint64_t{0xb6fc4fcd0722e3df}},
+      {"CJTT9WGcY2XykTdo8KodRIA29qsqY0iHzWZRjKHb9alwyJ7RZAE3V5Juv4MY3MeYEr1EPCC"
+       "MxO7yFXqT8XA8YTjaMp3bafRt17Pw8JC4iKJ1zN+WWKOESrj+"
+       "3aluGQqn8z1EzqY4PH7rLG575PYeWsP98BugdA==",
+       uint64_t{0x242da1e3a439bed8}, uint64_t{0x7cb86dcc55104aac}},
+      {"ZlhyQwLhXQyIUEnMH/"
+       "AEW27vh9xrbNKJxpWGtrEmKhd+nFqAfbeNBQjW0SfG1YI0xQkQMHXjuTt4P/"
+       "EpZRtA47ibZDVS8TtaxwyBjuIDwqcN09eCtpC+Ls+"
+       "vWDTLmBeDM3u4hmzz4DQAYsLiZYSJcldg9Q3wszw=",
+       uint64_t{0xdc559c746e35c139}, uint64_t{0x19e71e9b45c3a51e}},
+      {"v2KU8y0sCrBghmnm8lzGJlwo6D6ObccAxCf10heoDtYLosk4ztTpLlpSFEyu23MLA1tJkcg"
+       "Rko04h19QMG0mOw/"
+       "wc93EXAweriBqXfvdaP85sZABwiKO+6rtS9pacRVpYYhHJeVTQ5NzrvBvi1huxAr+"
+       "xswhVMfL",
+       uint64_t{0xd0b0350275b9989}, uint64_t{0x51de38573c2bea48}},
+      {"QhKlnIS6BuVCTQsnoE67E/"
+       "yrgogE8EwO7xLaEGei26m0gEU4OksefJgppDh3X0x0Cs78Dr9IHK5b977CmZlrTRmwhlP8p"
+       "M+UzXPNRNIZuN3ntOum/QhUWP8SGpirheXENWsXMQ/"
+       "nxtxakyEtrNkKk471Oov9juP8oQ==",
+       uint64_t{0xb04489e41d17730c}, uint64_t{0xa73ab6996d6df158}},
+      {"/ZRMgnoRt+Uo6fUPr9FqQvKX7syhgVqWu+"
+       "WUSsiQ68UlN0efSP6Eced5gJZL6tg9gcYJIkhjuQNITU0Q3TjVAnAcobgbJikCn6qZ6pRxK"
+       "BY4MTiAlfGD3T7R7hwJwx554MAy++Zb/YUFlnCaCJiwQMnowF7aQzwYFCo=",
+       uint64_t{0x2217285eb4572156}, uint64_t{0x55ef2b8c930817b2}},
+      {"NB7tU5fNE8nI+SXGfipc7sRkhnSkUF1krjeo6k+8FITaAtdyz+"
+       "o7mONgXmGLulBPH9bEwyYhKNVY0L+njNQrZ9YC2aXsFD3PdZsxAFaBT3VXEzh+"
+       "NGBTjDASNL3mXyS8Yv1iThGfHoY7T4aR0NYGJ+k+pR6f+KrPC96M",
+       uint64_t{0x12c2e8e68aede73b}, uint64_t{0xb2850bf5fae87157}},
+      {"8T6wrqCtEO6/rwxF6lvMeyuigVOLwPipX/FULvwyu+1wa5sQGav/"
+       "2FsLHUVn6cGSi0LlFwLewGHPFJDLR0u4t7ZUyM//"
+       "x6da0sWgOa5hzDqjsVGmjxEHXiaXKW3i4iSZNuxoNbMQkIbVML+"
+       "DkYu9ND0O2swg4itGeVSzXA==",
+       uint64_t{0x4d612125bdc4fd00}, uint64_t{0xecf3de1acd04651f}},
+      {"Ntf1bMRdondtMv1CYr3G80iDJ4WSAlKy5H34XdGruQiCrnRGDBa+"
+       "eUi7vKp4gp3BBcVGl8eYSasVQQjn7MLvb3BjtXx6c/"
+       "bCL7JtpzQKaDnPr9GWRxpBXVxKREgMM7d8lm35EODv0w+"
+       "hQLfVSh8OGs7fsBb68nNWPLeeSOo=",
+       uint64_t{0x81826b553954464e}, uint64_t{0xcc0a40552559ff32}},
+      {"VsSAw72Ro6xks02kaiLuiTEIWBC5bgqr4WDnmP8vglXzAhixk7td926rm9jNimL+"
+       "kroPSygZ9gl63aF5DCPOACXmsbmhDrAQuUzoh9ZKhWgElLQsrqo1KIjWoZT5b5QfVUXY9lS"
+       "IBg3U75SqORoTPq7HalxxoIT5diWOcJQi",
+       uint64_t{0xc2e5d345dc0ddd2d}, uint64_t{0xc385c374f20315b1}},
+      {"j+loZ+C87+"
+       "bJxNVebg94gU0mSLeDulcHs84tQT7BZM2rzDSLiCNxUedHr1ZWJ9ejTiBa0dqy2I2ABc++"
+       "xzOLcv+//YfibtjKtYggC6/3rv0XCc7xu6d/"
+       "O6xO+XOBhOWAQ+IHJVHf7wZnDxIXB8AUHsnjEISKj7823biqXjyP3g==",
+       uint64_t{0x3da6830a9e32631e}, uint64_t{0xb90208a4c7234183}},
+      {"f3LlpcPElMkspNtDq5xXyWU62erEaKn7RWKlo540gR6mZsNpK1czV/"
+       "sOmqaq8XAQLEn68LKj6/"
+       "cFkJukxRzCa4OF1a7cCAXYFp9+wZDu0bw4y63qbpjhdCl8GO6Z2lkcXy7KOzbPE01ukg7+"
+       "gN+7uKpoohgAhIwpAKQXmX5xtd0=",
+       uint64_t{0xc9ae5c8759b4877a}, uint64_t{0x58aa1ca7a4c075d9}},
+  };
+
+  for (const auto& expected_result : expected_results) {
+    std::string str;
+    ASSERT_TRUE(absl::Base64Unescape(expected_result.base64_data, &str));
+    EXPECT_EQ(absl::hash_internal::Wyhash(str.data(), str.size(),
+                                          expected_result.seed, kSalt),
+              expected_result.hash);
+  }
+}
+
+}  // namespace
diff --git a/absl/random/internal/randen.cc b/absl/random/internal/randen.cc
index 78a1e00c..c1bc0444 100644
--- a/absl/random/internal/randen.cc
+++ b/absl/random/internal/randen.cc
@@ -17,7 +17,7 @@
 #include "absl/base/internal/raw_logging.h"
 #include "absl/random/internal/randen_detect.h"
 
-// RANDen = RANDom generator or beetroots in Swiss German.
+// RANDen = RANDom generator or beetroots in Swiss High German.
 // 'Strong' (well-distributed, unpredictable, backtracking-resistant) random
 // generator, faster in some benchmarks than std::mt19937_64 and pcg64_c32.
 //
diff --git a/absl/random/internal/randen.h b/absl/random/internal/randen.h
index c2834aaf..9a3840b8 100644
--- a/absl/random/internal/randen.h
+++ b/absl/random/internal/randen.h
@@ -26,7 +26,7 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace random_internal {
 
-// RANDen = RANDom generator or beetroots in Swiss German.
+// RANDen = RANDom generator or beetroots in Swiss High German.
 // 'Strong' (well-distributed, unpredictable, backtracking-resistant) random
 // generator, faster in some benchmarks than std::mt19937_64 and pcg64_c32.
 //
diff --git a/absl/random/internal/randen_hwaes.h b/absl/random/internal/randen_hwaes.h
index bce36b52..71a7f69f 100644
--- a/absl/random/internal/randen_hwaes.h
+++ b/absl/random/internal/randen_hwaes.h
@@ -26,7 +26,7 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace random_internal {
 
-// RANDen = RANDom generator or beetroots in Swiss German.
+// RANDen = RANDom generator or beetroots in Swiss High German.
 // 'Strong' (well-distributed, unpredictable, backtracking-resistant) random
 // generator, faster in some benchmarks than std::mt19937_64 and pcg64_c32.
 //
diff --git a/absl/random/internal/randen_slow.h b/absl/random/internal/randen_slow.h
index b6f137eb..532c3a89 100644
--- a/absl/random/internal/randen_slow.h
+++ b/absl/random/internal/randen_slow.h
@@ -23,7 +23,7 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace random_internal {
 
-// RANDen = RANDom generator or beetroots in Swiss German.
+// RANDen = RANDom generator or beetroots in Swiss High German.
 // RandenSlow implements the basic state manipulation methods for
 // architectures lacking AES hardware acceleration intrinsics.
 class RandenSlow {
diff --git a/absl/random/internal/randen_traits.h b/absl/random/internal/randen_traits.h
index 53caa936..120022c9 100644
--- a/absl/random/internal/randen_traits.h
+++ b/absl/random/internal/randen_traits.h
@@ -28,7 +28,7 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace random_internal {
 
-// RANDen = RANDom generator or beetroots in Swiss German.
+// RANDen = RANDom generator or beetroots in Swiss High German.
 // 'Strong' (well-distributed, unpredictable, backtracking-resistant) random
 // generator, faster in some benchmarks than std::mt19937_64 and pcg64_c32.
 //
diff --git a/absl/strings/cord.cc b/absl/strings/cord.cc
index 9efd1357..ec1e9709 100644
--- a/absl/strings/cord.cc
+++ b/absl/strings/cord.cc
@@ -53,6 +53,7 @@ using ::absl::cord_internal::CordRepSubstring;
 using ::absl::cord_internal::CONCAT;
 using ::absl::cord_internal::EXTERNAL;
 using ::absl::cord_internal::FLAT;
+using ::absl::cord_internal::MAX_FLAT_TAG;
 using ::absl::cord_internal::SUBSTRING;
 
 namespace cord_internal {
@@ -95,9 +96,21 @@ static const size_t kFlatOverhead = offsetof(CordRep, data);
 // Flat allocation size is stored in tag, which currently can encode sizes up
 // to 4K, encoded as multiple of either 8 or 32 bytes.
 // If we allow for larger sizes, we need to change this to 8/64, 16/128, etc.
+// kMinFlatSize is bounded by tag needing to be at least FLAT * 8 bytes, and
+// ideally a 'nice' size aligning with allocation and cacheline sizes like 32.
+// kMaxFlatSize is bounded by the size resulting in a computed tag no greater
+// than MAX_FLAT_TAG. MAX_FLAT_TAG provides for additional 'high' tag values.
+static constexpr size_t kMinFlatSize = 32;
 static constexpr size_t kMaxFlatSize = 4096;
 static constexpr size_t kMaxFlatLength = kMaxFlatSize - kFlatOverhead;
-static constexpr size_t kMinFlatLength = 32 - kFlatOverhead;
+static constexpr size_t kMinFlatLength = kMinFlatSize - kFlatOverhead;
+
+static constexpr size_t AllocatedSizeToTagUnchecked(size_t size) {
+  return (size <= 1024) ? size / 8 : 128 + size / 32 - 1024 / 32;
+}
+
+static_assert(kMinFlatSize / 8 >= FLAT, "");
+static_assert(AllocatedSizeToTagUnchecked(kMaxFlatSize) <= MAX_FLAT_TAG, "");
 
 // Prefer copying blocks of at most this size, otherwise reference count.
 static const size_t kMaxBytesToCopy = 511;
@@ -117,7 +130,7 @@ static size_t RoundUpForTag(size_t size) {
 // undefined if the size exceeds the maximum size that can be encoded in
 // a tag, i.e., if size is larger than TagToAllocatedSize(<max tag>).
 static uint8_t AllocatedSizeToTag(size_t size) {
-  const size_t tag = (size <= 1024) ? size / 8 : 128 + size / 32 - 1024 / 32;
+  const size_t tag = AllocatedSizeToTagUnchecked(size);
   assert(tag <= std::numeric_limits<uint8_t>::max());
   return tag;
 }
diff --git a/absl/strings/internal/cord_internal.h b/absl/strings/internal/cord_internal.h
index aa91a691..195a7988 100644
--- a/absl/strings/internal/cord_internal.h
+++ b/absl/strings/internal/cord_internal.h
@@ -116,10 +116,16 @@ enum CordRepKind {
   CONCAT        = 0,
   EXTERNAL      = 1,
   SUBSTRING     = 2,
+  RING          = 3,
 
   // We have different tags for different sized flat arrays,
-  // starting with FLAT
-  FLAT          = 3,
+  // starting with FLAT, and limited to MAX_FLAT_TAG. The 224 value is based on
+  // the current 'size to tag' encoding of 8 / 32 bytes. If a new tag is needed
+  // in the future, then 'FLAT' and 'MAX_FLAT_TAG' should be adjusted as well
+  // as the Tag <---> Size logic so that FLAT stil represents the minimum flat
+  // allocation size. (32 bytes as of now).
+  FLAT = 4,
+  MAX_FLAT_TAG = 224,
 };
 
 struct CordRep {
diff --git a/absl/strings/internal/string_constant.h b/absl/strings/internal/string_constant.h
index b15f1d9b..a11336b7 100644
--- a/absl/strings/internal/string_constant.h
+++ b/absl/strings/internal/string_constant.h
@@ -35,18 +35,12 @@ namespace strings_internal {
 // below.
 template <typename T>
 struct StringConstant {
- private:
-  // Returns true if `view` points to constant data.
-  // Otherwise, it can't be constant evaluated.
-  static constexpr bool ValidateConstant(absl::string_view view) {
-    return view.empty() || 2 * view[0] != 1;
-  }
-
- public:
   static constexpr absl::string_view value = T{}();
   constexpr absl::string_view operator()() const { return value; }
 
-  static_assert(ValidateConstant(value),
+  // Check to be sure `view` points to constant data.
+  // Otherwise, it can't be constant evaluated.
+  static_assert(value.empty() || 2 * value[0] != 1,
                 "The input string_view must point to constant data.");
 };