Export of internal Abseil changes

--
007ce045d5d38a727ededdb5bf06e64785fd73bd by Martijn Vels <mvels@google.com>:

Add `cord_enable_btree` feature flag (default false).

PiperOrigin-RevId: 383729939

--
98e7dc6a0407b0fd7b8713d883cdb3a766e0583d by Benjamin Barenblat <bbaren@google.com>:

Eliminate some byte swapping from randen_slow

Stop swapping bytes when serializing randen_slow’s Vector128 into and
out of memory. Instead, simply index different bytes in the AES round
function. This requires byte swapping the te{0..3} lookup tables, but it
produces an 8% speedup on my Xeon W-2135.

PiperOrigin-RevId: 383689402

--
180b6bf45049188840d439b16a28e6b968669340 by Evan Brown <ezb@google.com>:

Minor simplification in drop_deletes_without_resize() - save probe_offset outside the lambda.

Also, add some consts, avoid an auto, and use lambda capture by value instead of reference.

I realized that the compiler can already optimize this - https://godbolt.org/z/Wxd9c4TfK, but I think this way makes the code a bit clearer.

PiperOrigin-RevId: 383646658

--
781706a974c4dc1c0abbb6b801fca0550229e883 by Martijn Vels <mvels@google.com>:

Change storage to contain 3 bytes.

As per the comments in the code, this allows us to utilize all available space in CordRep that may otherwise be 'lost' in padding in derived clases. For the upcoming CordrepBtree class, we want a strong guarantee on having a 64 bytes aligned implementation.

PiperOrigin-RevId: 383633963

--
8fe22ecf92492fa6649938a2215934ebfe01c714 by Derek Mauro <dmauro@google.com>:

Remove reference to str_format_arg.h, which no longer exists

PiperOrigin-RevId: 383517865

--
79397f3b18f18c1e2d7aea993b687329d626ce64 by Benjamin Barenblat <bbaren@google.com>:

Use absl::uint128 for AES random number generator

Replace randen’s internal 128-bit integer struct, u64x2, with
absl::uint128. This eliminates some code and improves support for
big-endian platforms.
PiperOrigin-RevId: 383475671
GitOrigin-RevId: 007ce045d5d38a727ededdb5bf06e64785fd73bd
Change-Id: Ia9d9c40de557221f1744fb0d6d4d6ca7ac569070

9 files changed, 268 insertions, 287 deletions

diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index 03f199a5..a9034b0b 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -1654,18 +1654,18 @@ class raw_hash_set {
     slot_type* slot = reinterpret_cast<slot_type*>(&raw);
     for (size_t i = 0; i != capacity_; ++i) {
       if (!IsDeleted(ctrl_[i])) continue;
-      size_t hash = PolicyTraits::apply(HashElement{hash_ref()},
-                                        PolicyTraits::element(slots_ + i));
-      auto target = find_first_non_full(ctrl_, hash, capacity_);
-      size_t new_i = target.offset;
+      const size_t hash = PolicyTraits::apply(
+          HashElement{hash_ref()}, PolicyTraits::element(slots_ + i));
+      const FindInfo target = find_first_non_full(ctrl_, hash, capacity_);
+      const size_t new_i = target.offset;
       total_probe_length += target.probe_length;
 
       // Verify if the old and new i fall within the same group wrt the hash.
       // If they do, we don't need to move the object as it falls already in the
       // best probe we can.
-      const auto probe_index = [&](size_t pos) {
-        return ((pos - probe(ctrl_, hash, capacity_).offset()) & capacity_) /
-               Group::kWidth;
+      const size_t probe_offset = probe(ctrl_, hash, capacity_).offset();
+      const auto probe_index = [probe_offset, this](size_t pos) {
+        return ((pos - probe_offset) & capacity_) / Group::kWidth;
       };
 
       // Element doesn't move.
diff --git a/absl/random/internal/BUILD.bazel b/absl/random/internal/BUILD.bazel
index 6e06fe9a..cf6b5389 100644
--- a/absl/random/internal/BUILD.bazel
+++ b/absl/random/internal/BUILD.bazel
@@ -297,6 +297,7 @@ cc_library(
         ":platform",
         "//absl/base:config",
         "//absl/base:core_headers",
+        "//absl/numeric:int128",
     ],
 )
 
@@ -337,6 +338,7 @@ cc_library(
         ":platform",
         "//absl/base:config",
         "//absl/base:core_headers",
+        "//absl/numeric:int128",
     ],
 )
 
diff --git a/absl/random/internal/randen_hwaes.cc b/absl/random/internal/randen_hwaes.cc
index 3738cc38..ab51e4a3 100644
--- a/absl/random/internal/randen_hwaes.cc
+++ b/absl/random/internal/randen_hwaes.cc
@@ -23,6 +23,7 @@
 #include <cstring>
 
 #include "absl/base/attributes.h"
+#include "absl/numeric/int128.h"
 #include "absl/random/internal/platform.h"
 #include "absl/random/internal/randen_traits.h"
 
@@ -120,11 +121,6 @@ namespace {
 
 using absl::random_internal::RandenTraits;
 
-// Randen operates on 128-bit vectors.
-struct alignas(16) u64x2 {
-  uint64_t data[2];
-};
-
 }  // namespace
 
 // TARGET_CRYPTO defines a crypto attribute for each architecture.
@@ -186,7 +182,7 @@ inline ABSL_TARGET_CRYPTO Vector128 AesRound(const Vector128& state,
 }
 
 // Enables native loads in the round loop by pre-swapping.
-inline ABSL_TARGET_CRYPTO void SwapEndian(u64x2* state) {
+inline ABSL_TARGET_CRYPTO void SwapEndian(absl::uint128* state) {
   for (uint32_t block = 0; block < RandenTraits::kFeistelBlocks; ++block) {
     Vector128Store(ReverseBytes(Vector128Load(state + block)), state + block);
   }
@@ -327,7 +323,7 @@ namespace {
 
 // Block shuffles applies a shuffle to the entire state between AES rounds.
 // Improved odd-even shuffle from "New criterion for diffusion property".
-inline ABSL_TARGET_CRYPTO void BlockShuffle(u64x2* state) {
+inline ABSL_TARGET_CRYPTO void BlockShuffle(absl::uint128* state) {
   static_assert(RandenTraits::kFeistelBlocks == 16,
                 "Expecting 16 FeistelBlocks.");
 
@@ -374,8 +370,9 @@ inline ABSL_TARGET_CRYPTO void BlockShuffle(u64x2* state) {
 // per 16 bytes (vs. 10 for AES-CTR). Computing eight round functions in
 // parallel hides the 7-cycle AESNI latency on HSW. Note that the Feistel
 // XORs are 'free' (included in the second AES instruction).
-inline ABSL_TARGET_CRYPTO const u64x2* FeistelRound(
-    u64x2* state, const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
+inline ABSL_TARGET_CRYPTO const absl::uint128* FeistelRound(
+    absl::uint128* state,
+    const absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
   static_assert(RandenTraits::kFeistelBlocks == 16,
                 "Expecting 16 FeistelBlocks.");
 
@@ -436,7 +433,8 @@ inline ABSL_TARGET_CRYPTO const u64x2* FeistelRound(
 // 2^64 queries if the round function is a PRF. This is similar to the b=8 case
 // of Simpira v2, but more efficient than its generic construction for b=16.
 inline ABSL_TARGET_CRYPTO void Permute(
-    u64x2* state, const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
+    absl::uint128* state,
+    const absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
   // (Successfully unrolled; the first iteration jumps into the second half)
 #ifdef __clang__
 #pragma clang loop unroll_count(2)
@@ -473,10 +471,11 @@ void ABSL_TARGET_CRYPTO RandenHwAes::Absorb(const void* seed_void,
   static_assert(RandenTraits::kStateBytes / sizeof(Vector128) == 16,
                 "Unexpected Randen kStateBlocks");
 
-  auto* state =
-      reinterpret_cast<u64x2 * ABSL_RANDOM_INTERNAL_RESTRICT>(state_void);
+  auto* state = reinterpret_cast<absl::uint128 * ABSL_RANDOM_INTERNAL_RESTRICT>(
+      state_void);
   const auto* seed =
-      reinterpret_cast<const u64x2 * ABSL_RANDOM_INTERNAL_RESTRICT>(seed_void);
+      reinterpret_cast<const absl::uint128 * ABSL_RANDOM_INTERNAL_RESTRICT>(
+          seed_void);
 
   Vector128 b1 = Vector128Load(state + 1);
   b1 ^= Vector128Load(seed + 0);
@@ -545,8 +544,8 @@ void ABSL_TARGET_CRYPTO RandenHwAes::Generate(const void* keys_void,
   static_assert(RandenTraits::kCapacityBytes == sizeof(Vector128),
                 "Capacity mismatch");
 
-  auto* state = reinterpret_cast<u64x2*>(state_void);
-  const auto* keys = reinterpret_cast<const u64x2*>(keys_void);
+  auto* state = reinterpret_cast<absl::uint128*>(state_void);
+  const auto* keys = reinterpret_cast<const absl::uint128*>(keys_void);
 
   const Vector128 prev_inner = Vector128Load(state);
 
diff --git a/absl/random/internal/randen_slow.cc b/absl/random/internal/randen_slow.cc
index 4e5f3dc1..56aeb030 100644
--- a/absl/random/internal/randen_slow.cc
+++ b/absl/random/internal/randen_slow.cc
@@ -19,6 +19,7 @@
 #include <cstring>
 
 #include "absl/base/attributes.h"
+#include "absl/numeric/int128.h"
 #include "absl/random/internal/platform.h"
 #include "absl/random/internal/randen_traits.h"
 
@@ -38,192 +39,193 @@
 namespace {
 
 // AES portions based on rijndael-alg-fst.c,
-// https://fastcrypto.org/front/misc/rijndael-alg-fst.c
+// https://fastcrypto.org/front/misc/rijndael-alg-fst.c, and modified for
+// little-endianness.
 //
 // Implementation of
 // http://www.csrc.nist.gov/publications/fips/fips197/fips-197.pdf
 constexpr uint32_t te0[256] = {
-    0xc66363a5, 0xf87c7c84, 0xee777799, 0xf67b7b8d, 0xfff2f20d, 0xd66b6bbd,
-    0xde6f6fb1, 0x91c5c554, 0x60303050, 0x02010103, 0xce6767a9, 0x562b2b7d,
-    0xe7fefe19, 0xb5d7d762, 0x4dababe6, 0xec76769a, 0x8fcaca45, 0x1f82829d,
-    0x89c9c940, 0xfa7d7d87, 0xeffafa15, 0xb25959eb, 0x8e4747c9, 0xfbf0f00b,
-    0x41adadec, 0xb3d4d467, 0x5fa2a2fd, 0x45afafea, 0x239c9cbf, 0x53a4a4f7,
-    0xe4727296, 0x9bc0c05b, 0x75b7b7c2, 0xe1fdfd1c, 0x3d9393ae, 0x4c26266a,
-    0x6c36365a, 0x7e3f3f41, 0xf5f7f702, 0x83cccc4f, 0x6834345c, 0x51a5a5f4,
-    0xd1e5e534, 0xf9f1f108, 0xe2717193, 0xabd8d873, 0x62313153, 0x2a15153f,
-    0x0804040c, 0x95c7c752, 0x46232365, 0x9dc3c35e, 0x30181828, 0x379696a1,
-    0x0a05050f, 0x2f9a9ab5, 0x0e070709, 0x24121236, 0x1b80809b, 0xdfe2e23d,
-    0xcdebeb26, 0x4e272769, 0x7fb2b2cd, 0xea75759f, 0x1209091b, 0x1d83839e,
-    0x582c2c74, 0x341a1a2e, 0x361b1b2d, 0xdc6e6eb2, 0xb45a5aee, 0x5ba0a0fb,
-    0xa45252f6, 0x763b3b4d, 0xb7d6d661, 0x7db3b3ce, 0x5229297b, 0xdde3e33e,
-    0x5e2f2f71, 0x13848497, 0xa65353f5, 0xb9d1d168, 0x00000000, 0xc1eded2c,
-    0x40202060, 0xe3fcfc1f, 0x79b1b1c8, 0xb65b5bed, 0xd46a6abe, 0x8dcbcb46,
-    0x67bebed9, 0x7239394b, 0x944a4ade, 0x984c4cd4, 0xb05858e8, 0x85cfcf4a,
-    0xbbd0d06b, 0xc5efef2a, 0x4faaaae5, 0xedfbfb16, 0x864343c5, 0x9a4d4dd7,
-    0x66333355, 0x11858594, 0x8a4545cf, 0xe9f9f910, 0x04020206, 0xfe7f7f81,
-    0xa05050f0, 0x783c3c44, 0x259f9fba, 0x4ba8a8e3, 0xa25151f3, 0x5da3a3fe,
-    0x804040c0, 0x058f8f8a, 0x3f9292ad, 0x219d9dbc, 0x70383848, 0xf1f5f504,
-    0x63bcbcdf, 0x77b6b6c1, 0xafdada75, 0x42212163, 0x20101030, 0xe5ffff1a,
-    0xfdf3f30e, 0xbfd2d26d, 0x81cdcd4c, 0x180c0c14, 0x26131335, 0xc3ecec2f,
-    0xbe5f5fe1, 0x359797a2, 0x884444cc, 0x2e171739, 0x93c4c457, 0x55a7a7f2,
-    0xfc7e7e82, 0x7a3d3d47, 0xc86464ac, 0xba5d5de7, 0x3219192b, 0xe6737395,
-    0xc06060a0, 0x19818198, 0x9e4f4fd1, 0xa3dcdc7f, 0x44222266, 0x542a2a7e,
-    0x3b9090ab, 0x0b888883, 0x8c4646ca, 0xc7eeee29, 0x6bb8b8d3, 0x2814143c,
-    0xa7dede79, 0xbc5e5ee2, 0x160b0b1d, 0xaddbdb76, 0xdbe0e03b, 0x64323256,
-    0x743a3a4e, 0x140a0a1e, 0x924949db, 0x0c06060a, 0x4824246c, 0xb85c5ce4,
-    0x9fc2c25d, 0xbdd3d36e, 0x43acacef, 0xc46262a6, 0x399191a8, 0x319595a4,
-    0xd3e4e437, 0xf279798b, 0xd5e7e732, 0x8bc8c843, 0x6e373759, 0xda6d6db7,
-    0x018d8d8c, 0xb1d5d564, 0x9c4e4ed2, 0x49a9a9e0, 0xd86c6cb4, 0xac5656fa,
-    0xf3f4f407, 0xcfeaea25, 0xca6565af, 0xf47a7a8e, 0x47aeaee9, 0x10080818,
-    0x6fbabad5, 0xf0787888, 0x4a25256f, 0x5c2e2e72, 0x381c1c24, 0x57a6a6f1,
-    0x73b4b4c7, 0x97c6c651, 0xcbe8e823, 0xa1dddd7c, 0xe874749c, 0x3e1f1f21,
-    0x964b4bdd, 0x61bdbddc, 0x0d8b8b86, 0x0f8a8a85, 0xe0707090, 0x7c3e3e42,
-    0x71b5b5c4, 0xcc6666aa, 0x904848d8, 0x06030305, 0xf7f6f601, 0x1c0e0e12,
-    0xc26161a3, 0x6a35355f, 0xae5757f9, 0x69b9b9d0, 0x17868691, 0x99c1c158,
-    0x3a1d1d27, 0x279e9eb9, 0xd9e1e138, 0xebf8f813, 0x2b9898b3, 0x22111133,
-    0xd26969bb, 0xa9d9d970, 0x078e8e89, 0x339494a7, 0x2d9b9bb6, 0x3c1e1e22,
-    0x15878792, 0xc9e9e920, 0x87cece49, 0xaa5555ff, 0x50282878, 0xa5dfdf7a,
-    0x038c8c8f, 0x59a1a1f8, 0x09898980, 0x1a0d0d17, 0x65bfbfda, 0xd7e6e631,
-    0x844242c6, 0xd06868b8, 0x824141c3, 0x299999b0, 0x5a2d2d77, 0x1e0f0f11,
-    0x7bb0b0cb, 0xa85454fc, 0x6dbbbbd6, 0x2c16163a,
+    0xa56363c6, 0x847c7cf8, 0x997777ee, 0x8d7b7bf6, 0x0df2f2ff, 0xbd6b6bd6,
+    0xb16f6fde, 0x54c5c591, 0x50303060, 0x03010102, 0xa96767ce, 0x7d2b2b56,
+    0x19fefee7, 0x62d7d7b5, 0xe6abab4d, 0x9a7676ec, 0x45caca8f, 0x9d82821f,
+    0x40c9c989, 0x877d7dfa, 0x15fafaef, 0xeb5959b2, 0xc947478e, 0x0bf0f0fb,
+    0xecadad41, 0x67d4d4b3, 0xfda2a25f, 0xeaafaf45, 0xbf9c9c23, 0xf7a4a453,
+    0x967272e4, 0x5bc0c09b, 0xc2b7b775, 0x1cfdfde1, 0xae93933d, 0x6a26264c,
+    0x5a36366c, 0x413f3f7e, 0x02f7f7f5, 0x4fcccc83, 0x5c343468, 0xf4a5a551,
+    0x34e5e5d1, 0x08f1f1f9, 0x937171e2, 0x73d8d8ab, 0x53313162, 0x3f15152a,
+    0x0c040408, 0x52c7c795, 0x65232346, 0x5ec3c39d, 0x28181830, 0xa1969637,
+    0x0f05050a, 0xb59a9a2f, 0x0907070e, 0x36121224, 0x9b80801b, 0x3de2e2df,
+    0x26ebebcd, 0x6927274e, 0xcdb2b27f, 0x9f7575ea, 0x1b090912, 0x9e83831d,
+    0x742c2c58, 0x2e1a1a34, 0x2d1b1b36, 0xb26e6edc, 0xee5a5ab4, 0xfba0a05b,
+    0xf65252a4, 0x4d3b3b76, 0x61d6d6b7, 0xceb3b37d, 0x7b292952, 0x3ee3e3dd,
+    0x712f2f5e, 0x97848413, 0xf55353a6, 0x68d1d1b9, 0x00000000, 0x2cededc1,
+    0x60202040, 0x1ffcfce3, 0xc8b1b179, 0xed5b5bb6, 0xbe6a6ad4, 0x46cbcb8d,
+    0xd9bebe67, 0x4b393972, 0xde4a4a94, 0xd44c4c98, 0xe85858b0, 0x4acfcf85,
+    0x6bd0d0bb, 0x2aefefc5, 0xe5aaaa4f, 0x16fbfbed, 0xc5434386, 0xd74d4d9a,
+    0x55333366, 0x94858511, 0xcf45458a, 0x10f9f9e9, 0x06020204, 0x817f7ffe,
+    0xf05050a0, 0x443c3c78, 0xba9f9f25, 0xe3a8a84b, 0xf35151a2, 0xfea3a35d,
+    0xc0404080, 0x8a8f8f05, 0xad92923f, 0xbc9d9d21, 0x48383870, 0x04f5f5f1,
+    0xdfbcbc63, 0xc1b6b677, 0x75dadaaf, 0x63212142, 0x30101020, 0x1affffe5,
+    0x0ef3f3fd, 0x6dd2d2bf, 0x4ccdcd81, 0x140c0c18, 0x35131326, 0x2fececc3,
+    0xe15f5fbe, 0xa2979735, 0xcc444488, 0x3917172e, 0x57c4c493, 0xf2a7a755,
+    0x827e7efc, 0x473d3d7a, 0xac6464c8, 0xe75d5dba, 0x2b191932, 0x957373e6,
+    0xa06060c0, 0x98818119, 0xd14f4f9e, 0x7fdcdca3, 0x66222244, 0x7e2a2a54,
+    0xab90903b, 0x8388880b, 0xca46468c, 0x29eeeec7, 0xd3b8b86b, 0x3c141428,
+    0x79dedea7, 0xe25e5ebc, 0x1d0b0b16, 0x76dbdbad, 0x3be0e0db, 0x56323264,
+    0x4e3a3a74, 0x1e0a0a14, 0xdb494992, 0x0a06060c, 0x6c242448, 0xe45c5cb8,
+    0x5dc2c29f, 0x6ed3d3bd, 0xefacac43, 0xa66262c4, 0xa8919139, 0xa4959531,
+    0x37e4e4d3, 0x8b7979f2, 0x32e7e7d5, 0x43c8c88b, 0x5937376e, 0xb76d6dda,
+    0x8c8d8d01, 0x64d5d5b1, 0xd24e4e9c, 0xe0a9a949, 0xb46c6cd8, 0xfa5656ac,
+    0x07f4f4f3, 0x25eaeacf, 0xaf6565ca, 0x8e7a7af4, 0xe9aeae47, 0x18080810,
+    0xd5baba6f, 0x887878f0, 0x6f25254a, 0x722e2e5c, 0x241c1c38, 0xf1a6a657,
+    0xc7b4b473, 0x51c6c697, 0x23e8e8cb, 0x7cdddda1, 0x9c7474e8, 0x211f1f3e,
+    0xdd4b4b96, 0xdcbdbd61, 0x868b8b0d, 0x858a8a0f, 0x907070e0, 0x423e3e7c,
+    0xc4b5b571, 0xaa6666cc, 0xd8484890, 0x05030306, 0x01f6f6f7, 0x120e0e1c,
+    0xa36161c2, 0x5f35356a, 0xf95757ae, 0xd0b9b969, 0x91868617, 0x58c1c199,
+    0x271d1d3a, 0xb99e9e27, 0x38e1e1d9, 0x13f8f8eb, 0xb398982b, 0x33111122,
+    0xbb6969d2, 0x70d9d9a9, 0x898e8e07, 0xa7949433, 0xb69b9b2d, 0x221e1e3c,
+    0x92878715, 0x20e9e9c9, 0x49cece87, 0xff5555aa, 0x78282850, 0x7adfdfa5,
+    0x8f8c8c03, 0xf8a1a159, 0x80898909, 0x170d0d1a, 0xdabfbf65, 0x31e6e6d7,
+    0xc6424284, 0xb86868d0, 0xc3414182, 0xb0999929, 0x772d2d5a, 0x110f0f1e,
+    0xcbb0b07b, 0xfc5454a8, 0xd6bbbb6d, 0x3a16162c,
 };
 
 constexpr uint32_t te1[256] = {
-    0xa5c66363, 0x84f87c7c, 0x99ee7777, 0x8df67b7b, 0x0dfff2f2, 0xbdd66b6b,
-    0xb1de6f6f, 0x5491c5c5, 0x50603030, 0x03020101, 0xa9ce6767, 0x7d562b2b,
-    0x19e7fefe, 0x62b5d7d7, 0xe64dabab, 0x9aec7676, 0x458fcaca, 0x9d1f8282,
-    0x4089c9c9, 0x87fa7d7d, 0x15effafa, 0xebb25959, 0xc98e4747, 0x0bfbf0f0,
-    0xec41adad, 0x67b3d4d4, 0xfd5fa2a2, 0xea45afaf, 0xbf239c9c, 0xf753a4a4,
-    0x96e47272, 0x5b9bc0c0, 0xc275b7b7, 0x1ce1fdfd, 0xae3d9393, 0x6a4c2626,
-    0x5a6c3636, 0x417e3f3f, 0x02f5f7f7, 0x4f83cccc, 0x5c683434, 0xf451a5a5,
-    0x34d1e5e5, 0x08f9f1f1, 0x93e27171, 0x73abd8d8, 0x53623131, 0x3f2a1515,
-    0x0c080404, 0x5295c7c7, 0x65462323, 0x5e9dc3c3, 0x28301818, 0xa1379696,
-    0x0f0a0505, 0xb52f9a9a, 0x090e0707, 0x36241212, 0x9b1b8080, 0x3ddfe2e2,
-    0x26cdebeb, 0x694e2727, 0xcd7fb2b2, 0x9fea7575, 0x1b120909, 0x9e1d8383,
-    0x74582c2c, 0x2e341a1a, 0x2d361b1b, 0xb2dc6e6e, 0xeeb45a5a, 0xfb5ba0a0,
-    0xf6a45252, 0x4d763b3b, 0x61b7d6d6, 0xce7db3b3, 0x7b522929, 0x3edde3e3,
-    0x715e2f2f, 0x97138484, 0xf5a65353, 0x68b9d1d1, 0x00000000, 0x2cc1eded,
-    0x60402020, 0x1fe3fcfc, 0xc879b1b1, 0xedb65b5b, 0xbed46a6a, 0x468dcbcb,
-    0xd967bebe, 0x4b723939, 0xde944a4a, 0xd4984c4c, 0xe8b05858, 0x4a85cfcf,
-    0x6bbbd0d0, 0x2ac5efef, 0xe54faaaa, 0x16edfbfb, 0xc5864343, 0xd79a4d4d,
-    0x55663333, 0x94118585, 0xcf8a4545, 0x10e9f9f9, 0x06040202, 0x81fe7f7f,
-    0xf0a05050, 0x44783c3c, 0xba259f9f, 0xe34ba8a8, 0xf3a25151, 0xfe5da3a3,
-    0xc0804040, 0x8a058f8f, 0xad3f9292, 0xbc219d9d, 0x48703838, 0x04f1f5f5,
-    0xdf63bcbc, 0xc177b6b6, 0x75afdada, 0x63422121, 0x30201010, 0x1ae5ffff,
-    0x0efdf3f3, 0x6dbfd2d2, 0x4c81cdcd, 0x14180c0c, 0x35261313, 0x2fc3ecec,
-    0xe1be5f5f, 0xa2359797, 0xcc884444, 0x392e1717, 0x5793c4c4, 0xf255a7a7,
-    0x82fc7e7e, 0x477a3d3d, 0xacc86464, 0xe7ba5d5d, 0x2b321919, 0x95e67373,
-    0xa0c06060, 0x98198181, 0xd19e4f4f, 0x7fa3dcdc, 0x66442222, 0x7e542a2a,
-    0xab3b9090, 0x830b8888, 0xca8c4646, 0x29c7eeee, 0xd36bb8b8, 0x3c281414,
-    0x79a7dede, 0xe2bc5e5e, 0x1d160b0b, 0x76addbdb, 0x3bdbe0e0, 0x56643232,
-    0x4e743a3a, 0x1e140a0a, 0xdb924949, 0x0a0c0606, 0x6c482424, 0xe4b85c5c,
-    0x5d9fc2c2, 0x6ebdd3d3, 0xef43acac, 0xa6c46262, 0xa8399191, 0xa4319595,
-    0x37d3e4e4, 0x8bf27979, 0x32d5e7e7, 0x438bc8c8, 0x596e3737, 0xb7da6d6d,
-    0x8c018d8d, 0x64b1d5d5, 0xd29c4e4e, 0xe049a9a9, 0xb4d86c6c, 0xfaac5656,
-    0x07f3f4f4, 0x25cfeaea, 0xafca6565, 0x8ef47a7a, 0xe947aeae, 0x18100808,
-    0xd56fbaba, 0x88f07878, 0x6f4a2525, 0x725c2e2e, 0x24381c1c, 0xf157a6a6,
-    0xc773b4b4, 0x5197c6c6, 0x23cbe8e8, 0x7ca1dddd, 0x9ce87474, 0x213e1f1f,
-    0xdd964b4b, 0xdc61bdbd, 0x860d8b8b, 0x850f8a8a, 0x90e07070, 0x427c3e3e,
-    0xc471b5b5, 0xaacc6666, 0xd8904848, 0x05060303, 0x01f7f6f6, 0x121c0e0e,
-    0xa3c26161, 0x5f6a3535, 0xf9ae5757, 0xd069b9b9, 0x91178686, 0x5899c1c1,
-    0x273a1d1d, 0xb9279e9e, 0x38d9e1e1, 0x13ebf8f8, 0xb32b9898, 0x33221111,
-    0xbbd26969, 0x70a9d9d9, 0x89078e8e, 0xa7339494, 0xb62d9b9b, 0x223c1e1e,
-    0x92158787, 0x20c9e9e9, 0x4987cece, 0xffaa5555, 0x78502828, 0x7aa5dfdf,
-    0x8f038c8c, 0xf859a1a1, 0x80098989, 0x171a0d0d, 0xda65bfbf, 0x31d7e6e6,
-    0xc6844242, 0xb8d06868, 0xc3824141, 0xb0299999, 0x775a2d2d, 0x111e0f0f,
-    0xcb7bb0b0, 0xfca85454, 0xd66dbbbb, 0x3a2c1616,
+    0x6363c6a5, 0x7c7cf884, 0x7777ee99, 0x7b7bf68d, 0xf2f2ff0d, 0x6b6bd6bd,
+    0x6f6fdeb1, 0xc5c59154, 0x30306050, 0x01010203, 0x6767cea9, 0x2b2b567d,
+    0xfefee719, 0xd7d7b562, 0xabab4de6, 0x7676ec9a, 0xcaca8f45, 0x82821f9d,
+    0xc9c98940, 0x7d7dfa87, 0xfafaef15, 0x5959b2eb, 0x47478ec9, 0xf0f0fb0b,
+    0xadad41ec, 0xd4d4b367, 0xa2a25ffd, 0xafaf45ea, 0x9c9c23bf, 0xa4a453f7,
+    0x7272e496, 0xc0c09b5b, 0xb7b775c2, 0xfdfde11c, 0x93933dae, 0x26264c6a,
+    0x36366c5a, 0x3f3f7e41, 0xf7f7f502, 0xcccc834f, 0x3434685c, 0xa5a551f4,
+    0xe5e5d134, 0xf1f1f908, 0x7171e293, 0xd8d8ab73, 0x31316253, 0x15152a3f,
+    0x0404080c, 0xc7c79552, 0x23234665, 0xc3c39d5e, 0x18183028, 0x969637a1,
+    0x05050a0f, 0x9a9a2fb5, 0x07070e09, 0x12122436, 0x80801b9b, 0xe2e2df3d,
+    0xebebcd26, 0x27274e69, 0xb2b27fcd, 0x7575ea9f, 0x0909121b, 0x83831d9e,
+    0x2c2c5874, 0x1a1a342e, 0x1b1b362d, 0x6e6edcb2, 0x5a5ab4ee, 0xa0a05bfb,
+    0x5252a4f6, 0x3b3b764d, 0xd6d6b761, 0xb3b37dce, 0x2929527b, 0xe3e3dd3e,
+    0x2f2f5e71, 0x84841397, 0x5353a6f5, 0xd1d1b968, 0x00000000, 0xededc12c,
+    0x20204060, 0xfcfce31f, 0xb1b179c8, 0x5b5bb6ed, 0x6a6ad4be, 0xcbcb8d46,
+    0xbebe67d9, 0x3939724b, 0x4a4a94de, 0x4c4c98d4, 0x5858b0e8, 0xcfcf854a,
+    0xd0d0bb6b, 0xefefc52a, 0xaaaa4fe5, 0xfbfbed16, 0x434386c5, 0x4d4d9ad7,
+    0x33336655, 0x85851194, 0x45458acf, 0xf9f9e910, 0x02020406, 0x7f7ffe81,
+    0x5050a0f0, 0x3c3c7844, 0x9f9f25ba, 0xa8a84be3, 0x5151a2f3, 0xa3a35dfe,
+    0x404080c0, 0x8f8f058a, 0x92923fad, 0x9d9d21bc, 0x38387048, 0xf5f5f104,
+    0xbcbc63df, 0xb6b677c1, 0xdadaaf75, 0x21214263, 0x10102030, 0xffffe51a,
+    0xf3f3fd0e, 0xd2d2bf6d, 0xcdcd814c, 0x0c0c1814, 0x13132635, 0xececc32f,
+    0x5f5fbee1, 0x979735a2, 0x444488cc, 0x17172e39, 0xc4c49357, 0xa7a755f2,
+    0x7e7efc82, 0x3d3d7a47, 0x6464c8ac, 0x5d5dbae7, 0x1919322b, 0x7373e695,
+    0x6060c0a0, 0x81811998, 0x4f4f9ed1, 0xdcdca37f, 0x22224466, 0x2a2a547e,
+    0x90903bab, 0x88880b83, 0x46468cca, 0xeeeec729, 0xb8b86bd3, 0x1414283c,
+    0xdedea779, 0x5e5ebce2, 0x0b0b161d, 0xdbdbad76, 0xe0e0db3b, 0x32326456,
+    0x3a3a744e, 0x0a0a141e, 0x494992db, 0x06060c0a, 0x2424486c, 0x5c5cb8e4,
+    0xc2c29f5d, 0xd3d3bd6e, 0xacac43ef, 0x6262c4a6, 0x919139a8, 0x959531a4,
+    0xe4e4d337, 0x7979f28b, 0xe7e7d532, 0xc8c88b43, 0x37376e59, 0x6d6ddab7,
+    0x8d8d018c, 0xd5d5b164, 0x4e4e9cd2, 0xa9a949e0, 0x6c6cd8b4, 0x5656acfa,
+    0xf4f4f307, 0xeaeacf25, 0x6565caaf, 0x7a7af48e, 0xaeae47e9, 0x08081018,
+    0xbaba6fd5, 0x7878f088, 0x25254a6f, 0x2e2e5c72, 0x1c1c3824, 0xa6a657f1,
+    0xb4b473c7, 0xc6c69751, 0xe8e8cb23, 0xdddda17c, 0x7474e89c, 0x1f1f3e21,
+    0x4b4b96dd, 0xbdbd61dc, 0x8b8b0d86, 0x8a8a0f85, 0x7070e090, 0x3e3e7c42,
+    0xb5b571c4, 0x6666ccaa, 0x484890d8, 0x03030605, 0xf6f6f701, 0x0e0e1c12,
+    0x6161c2a3, 0x35356a5f, 0x5757aef9, 0xb9b969d0, 0x86861791, 0xc1c19958,
+    0x1d1d3a27, 0x9e9e27b9, 0xe1e1d938, 0xf8f8eb13, 0x98982bb3, 0x11112233,
+    0x6969d2bb, 0xd9d9a970, 0x8e8e0789, 0x949433a7, 0x9b9b2db6, 0x1e1e3c22,
+    0x87871592, 0xe9e9c920, 0xcece8749, 0x5555aaff, 0x28285078, 0xdfdfa57a,
+    0x8c8c038f, 0xa1a159f8, 0x89890980, 0x0d0d1a17, 0xbfbf65da, 0xe6e6d731,
+    0x424284c6, 0x6868d0b8, 0x414182c3, 0x999929b0, 0x2d2d5a77, 0x0f0f1e11,
+    0xb0b07bcb, 0x5454a8fc, 0xbbbb6dd6, 0x16162c3a,
 };
 
 constexpr uint32_t te2[256] = {
-    0x63a5c663, 0x7c84f87c, 0x7799ee77, 0x7b8df67b, 0xf20dfff2, 0x6bbdd66b,
-    0x6fb1de6f, 0xc55491c5, 0x30506030, 0x01030201, 0x67a9ce67, 0x2b7d562b,
-    0xfe19e7fe, 0xd762b5d7, 0xabe64dab, 0x769aec76, 0xca458fca, 0x829d1f82,
-    0xc94089c9, 0x7d87fa7d, 0xfa15effa, 0x59ebb259, 0x47c98e47, 0xf00bfbf0,
-    0xadec41ad, 0xd467b3d4, 0xa2fd5fa2, 0xafea45af, 0x9cbf239c, 0xa4f753a4,
-    0x7296e472, 0xc05b9bc0, 0xb7c275b7, 0xfd1ce1fd, 0x93ae3d93, 0x266a4c26,
-    0x365a6c36, 0x3f417e3f, 0xf702f5f7, 0xcc4f83cc, 0x345c6834, 0xa5f451a5,
-    0xe534d1e5, 0xf108f9f1, 0x7193e271, 0xd873abd8, 0x31536231, 0x153f2a15,
-    0x040c0804, 0xc75295c7, 0x23654623, 0xc35e9dc3, 0x18283018, 0x96a13796,
-    0x050f0a05, 0x9ab52f9a, 0x07090e07, 0x12362412, 0x809b1b80, 0xe23ddfe2,
-    0xeb26cdeb, 0x27694e27, 0xb2cd7fb2, 0x759fea75, 0x091b1209, 0x839e1d83,
-    0x2c74582c, 0x1a2e341a, 0x1b2d361b, 0x6eb2dc6e, 0x5aeeb45a, 0xa0fb5ba0,
-    0x52f6a452, 0x3b4d763b, 0xd661b7d6, 0xb3ce7db3, 0x297b5229, 0xe33edde3,
-    0x2f715e2f, 0x84971384, 0x53f5a653, 0xd168b9d1, 0x00000000, 0xed2cc1ed,
-    0x20604020, 0xfc1fe3fc, 0xb1c879b1, 0x5bedb65b, 0x6abed46a, 0xcb468dcb,
-    0xbed967be, 0x394b7239, 0x4ade944a, 0x4cd4984c, 0x58e8b058, 0xcf4a85cf,
-    0xd06bbbd0, 0xef2ac5ef, 0xaae54faa, 0xfb16edfb, 0x43c58643, 0x4dd79a4d,
-    0x33556633, 0x85941185, 0x45cf8a45, 0xf910e9f9, 0x02060402, 0x7f81fe7f,
-    0x50f0a050, 0x3c44783c, 0x9fba259f, 0xa8e34ba8, 0x51f3a251, 0xa3fe5da3,
-    0x40c08040, 0x8f8a058f, 0x92ad3f92, 0x9dbc219d, 0x38487038, 0xf504f1f5,
-    0xbcdf63bc, 0xb6c177b6, 0xda75afda, 0x21634221, 0x10302010, 0xff1ae5ff,
-    0xf30efdf3, 0xd26dbfd2, 0xcd4c81cd, 0x0c14180c, 0x13352613, 0xec2fc3ec,
-    0x5fe1be5f, 0x97a23597, 0x44cc8844, 0x17392e17, 0xc45793c4, 0xa7f255a7,
-    0x7e82fc7e, 0x3d477a3d, 0x64acc864, 0x5de7ba5d, 0x192b3219, 0x7395e673,
-    0x60a0c060, 0x81981981, 0x4fd19e4f, 0xdc7fa3dc, 0x22664422, 0x2a7e542a,
-    0x90ab3b90, 0x88830b88, 0x46ca8c46, 0xee29c7ee, 0xb8d36bb8, 0x143c2814,
-    0xde79a7de, 0x5ee2bc5e, 0x0b1d160b, 0xdb76addb, 0xe03bdbe0, 0x32566432,
-    0x3a4e743a, 0x0a1e140a, 0x49db9249, 0x060a0c06, 0x246c4824, 0x5ce4b85c,
-    0xc25d9fc2, 0xd36ebdd3, 0xacef43ac, 0x62a6c462, 0x91a83991, 0x95a43195,
-    0xe437d3e4, 0x798bf279, 0xe732d5e7, 0xc8438bc8, 0x37596e37, 0x6db7da6d,
-    0x8d8c018d, 0xd564b1d5, 0x4ed29c4e, 0xa9e049a9, 0x6cb4d86c, 0x56faac56,
-    0xf407f3f4, 0xea25cfea, 0x65afca65, 0x7a8ef47a, 0xaee947ae, 0x08181008,
-    0xbad56fba, 0x7888f078, 0x256f4a25, 0x2e725c2e, 0x1c24381c, 0xa6f157a6,
-    0xb4c773b4, 0xc65197c6, 0xe823cbe8, 0xdd7ca1dd, 0x749ce874, 0x1f213e1f,
-    0x4bdd964b, 0xbddc61bd, 0x8b860d8b, 0x8a850f8a, 0x7090e070, 0x3e427c3e,
-    0xb5c471b5, 0x66aacc66, 0x48d89048, 0x03050603, 0xf601f7f6, 0x0e121c0e,
-    0x61a3c261, 0x355f6a35, 0x57f9ae57, 0xb9d069b9, 0x86911786, 0xc15899c1,
-    0x1d273a1d, 0x9eb9279e, 0xe138d9e1, 0xf813ebf8, 0x98b32b98, 0x11332211,
-    0x69bbd269, 0xd970a9d9, 0x8e89078e, 0x94a73394, 0x9bb62d9b, 0x1e223c1e,
-    0x87921587, 0xe920c9e9, 0xce4987ce, 0x55ffaa55, 0x28785028, 0xdf7aa5df,
-    0x8c8f038c, 0xa1f859a1, 0x89800989, 0x0d171a0d, 0xbfda65bf, 0xe631d7e6,
-    0x42c68442, 0x68b8d068, 0x41c38241, 0x99b02999, 0x2d775a2d, 0x0f111e0f,
-    0xb0cb7bb0, 0x54fca854, 0xbbd66dbb, 0x163a2c16,
+    0x63c6a563, 0x7cf8847c, 0x77ee9977, 0x7bf68d7b, 0xf2ff0df2, 0x6bd6bd6b,
+    0x6fdeb16f, 0xc59154c5, 0x30605030, 0x01020301, 0x67cea967, 0x2b567d2b,
+    0xfee719fe, 0xd7b562d7, 0xab4de6ab, 0x76ec9a76, 0xca8f45ca, 0x821f9d82,
+    0xc98940c9, 0x7dfa877d, 0xfaef15fa, 0x59b2eb59, 0x478ec947, 0xf0fb0bf0,
+    0xad41ecad, 0xd4b367d4, 0xa25ffda2, 0xaf45eaaf, 0x9c23bf9c, 0xa453f7a4,
+    0x72e49672, 0xc09b5bc0, 0xb775c2b7, 0xfde11cfd, 0x933dae93, 0x264c6a26,
+    0x366c5a36, 0x3f7e413f, 0xf7f502f7, 0xcc834fcc, 0x34685c34, 0xa551f4a5,
+    0xe5d134e5, 0xf1f908f1, 0x71e29371, 0xd8ab73d8, 0x31625331, 0x152a3f15,
+    0x04080c04, 0xc79552c7, 0x23466523, 0xc39d5ec3, 0x18302818, 0x9637a196,
+    0x050a0f05, 0x9a2fb59a, 0x070e0907, 0x12243612, 0x801b9b80, 0xe2df3de2,
+    0xebcd26eb, 0x274e6927, 0xb27fcdb2, 0x75ea9f75, 0x09121b09, 0x831d9e83,
+    0x2c58742c, 0x1a342e1a, 0x1b362d1b, 0x6edcb26e, 0x5ab4ee5a, 0xa05bfba0,
+    0x52a4f652, 0x3b764d3b, 0xd6b761d6, 0xb37dceb3, 0x29527b29, 0xe3dd3ee3,
+    0x2f5e712f, 0x84139784, 0x53a6f553, 0xd1b968d1, 0x00000000, 0xedc12ced,
+    0x20406020, 0xfce31ffc, 0xb179c8b1, 0x5bb6ed5b, 0x6ad4be6a, 0xcb8d46cb,
+    0xbe67d9be, 0x39724b39, 0x4a94de4a, 0x4c98d44c, 0x58b0e858, 0xcf854acf,
+    0xd0bb6bd0, 0xefc52aef, 0xaa4fe5aa, 0xfbed16fb, 0x4386c543, 0x4d9ad74d,
+    0x33665533, 0x85119485, 0x458acf45, 0xf9e910f9, 0x02040602, 0x7ffe817f,
+    0x50a0f050, 0x3c78443c, 0x9f25ba9f, 0xa84be3a8, 0x51a2f351, 0xa35dfea3,
+    0x4080c040, 0x8f058a8f, 0x923fad92, 0x9d21bc9d, 0x38704838, 0xf5f104f5,
+    0xbc63dfbc, 0xb677c1b6, 0xdaaf75da, 0x21426321, 0x10203010, 0xffe51aff,
+    0xf3fd0ef3, 0xd2bf6dd2, 0xcd814ccd, 0x0c18140c, 0x13263513, 0xecc32fec,
+    0x5fbee15f, 0x9735a297, 0x4488cc44, 0x172e3917, 0xc49357c4, 0xa755f2a7,
+    0x7efc827e, 0x3d7a473d, 0x64c8ac64, 0x5dbae75d, 0x19322b19, 0x73e69573,
+    0x60c0a060, 0x81199881, 0x4f9ed14f, 0xdca37fdc, 0x22446622, 0x2a547e2a,
+    0x903bab90, 0x880b8388, 0x468cca46, 0xeec729ee, 0xb86bd3b8, 0x14283c14,
+    0xdea779de, 0x5ebce25e, 0x0b161d0b, 0xdbad76db, 0xe0db3be0, 0x32645632,
+    0x3a744e3a, 0x0a141e0a, 0x4992db49, 0x060c0a06, 0x24486c24, 0x5cb8e45c,
+    0xc29f5dc2, 0xd3bd6ed3, 0xac43efac, 0x62c4a662, 0x9139a891, 0x9531a495,
+    0xe4d337e4, 0x79f28b79, 0xe7d532e7, 0xc88b43c8, 0x376e5937, 0x6ddab76d,
+    0x8d018c8d, 0xd5b164d5, 0x4e9cd24e, 0xa949e0a9, 0x6cd8b46c, 0x56acfa56,
+    0xf4f307f4, 0xeacf25ea, 0x65caaf65, 0x7af48e7a, 0xae47e9ae, 0x08101808,
+    0xba6fd5ba, 0x78f08878, 0x254a6f25, 0x2e5c722e, 0x1c38241c, 0xa657f1a6,
+    0xb473c7b4, 0xc69751c6, 0xe8cb23e8, 0xdda17cdd, 0x74e89c74, 0x1f3e211f,
+    0x4b96dd4b, 0xbd61dcbd, 0x8b0d868b, 0x8a0f858a, 0x70e09070, 0x3e7c423e,
+    0xb571c4b5, 0x66ccaa66, 0x4890d848, 0x03060503, 0xf6f701f6, 0x0e1c120e,
+    0x61c2a361, 0x356a5f35, 0x57aef957, 0xb969d0b9, 0x86179186, 0xc19958c1,
+    0x1d3a271d, 0x9e27b99e, 0xe1d938e1, 0xf8eb13f8, 0x982bb398, 0x11223311,
+    0x69d2bb69, 0xd9a970d9, 0x8e07898e, 0x9433a794, 0x9b2db69b, 0x1e3c221e,
+    0x87159287, 0xe9c920e9, 0xce8749ce, 0x55aaff55, 0x28507828, 0xdfa57adf,
+    0x8c038f8c, 0xa159f8a1, 0x89098089, 0x0d1a170d, 0xbf65dabf, 0xe6d731e6,
+    0x4284c642, 0x68d0b868, 0x4182c341, 0x9929b099, 0x2d5a772d, 0x0f1e110f,
+    0xb07bcbb0, 0x54a8fc54, 0xbb6dd6bb, 0x162c3a16,
 };
 
 constexpr uint32_t te3[256] = {
-    0x6363a5c6, 0x7c7c84f8, 0x777799ee, 0x7b7b8df6, 0xf2f20dff, 0x6b6bbdd6,
-    0x6f6fb1de, 0xc5c55491, 0x30305060, 0x01010302, 0x6767a9ce, 0x2b2b7d56,
-    0xfefe19e7, 0xd7d762b5, 0xababe64d, 0x76769aec, 0xcaca458f, 0x82829d1f,
-    0xc9c94089, 0x7d7d87fa, 0xfafa15ef, 0x5959ebb2, 0x4747c98e, 0xf0f00bfb,
-    0xadadec41, 0xd4d467b3, 0xa2a2fd5f, 0xafafea45, 0x9c9cbf23, 0xa4a4f753,
-    0x727296e4, 0xc0c05b9b, 0xb7b7c275, 0xfdfd1ce1, 0x9393ae3d, 0x26266a4c,
-    0x36365a6c, 0x3f3f417e, 0xf7f702f5, 0xcccc4f83, 0x34345c68, 0xa5a5f451,
-    0xe5e534d1, 0xf1f108f9, 0x717193e2, 0xd8d873ab, 0x31315362, 0x15153f2a,
-    0x04040c08, 0xc7c75295, 0x23236546, 0xc3c35e9d, 0x18182830, 0x9696a137,
-    0x05050f0a, 0x9a9ab52f, 0x0707090e, 0x12123624, 0x80809b1b, 0xe2e23ddf,
-    0xebeb26cd, 0x2727694e, 0xb2b2cd7f, 0x75759fea, 0x09091b12, 0x83839e1d,
-    0x2c2c7458, 0x1a1a2e34, 0x1b1b2d36, 0x6e6eb2dc, 0x5a5aeeb4, 0xa0a0fb5b,
-    0x5252f6a4, 0x3b3b4d76, 0xd6d661b7, 0xb3b3ce7d, 0x29297b52, 0xe3e33edd,
-    0x2f2f715e, 0x84849713, 0x5353f5a6, 0xd1d168b9, 0x00000000, 0xeded2cc1,
-    0x20206040, 0xfcfc1fe3, 0xb1b1c879, 0x5b5bedb6, 0x6a6abed4, 0xcbcb468d,
-    0xbebed967, 0x39394b72, 0x4a4ade94, 0x4c4cd498, 0x5858e8b0, 0xcfcf4a85,
-    0xd0d06bbb, 0xefef2ac5, 0xaaaae54f, 0xfbfb16ed, 0x4343c586, 0x4d4dd79a,
-    0x33335566, 0x85859411, 0x4545cf8a, 0xf9f910e9, 0x02020604, 0x7f7f81fe,
-    0x5050f0a0, 0x3c3c4478, 0x9f9fba25, 0xa8a8e34b, 0x5151f3a2, 0xa3a3fe5d,
-    0x4040c080, 0x8f8f8a05, 0x9292ad3f, 0x9d9dbc21, 0x38384870, 0xf5f504f1,
-    0xbcbcdf63, 0xb6b6c177, 0xdada75af, 0x21216342, 0x10103020, 0xffff1ae5,
-    0xf3f30efd, 0xd2d26dbf, 0xcdcd4c81, 0x0c0c1418, 0x13133526, 0xecec2fc3,
-    0x5f5fe1be, 0x9797a235, 0x4444cc88, 0x1717392e, 0xc4c45793, 0xa7a7f255,
-    0x7e7e82fc, 0x3d3d477a, 0x6464acc8, 0x5d5de7ba, 0x19192b32, 0x737395e6,
-    0x6060a0c0, 0x81819819, 0x4f4fd19e, 0xdcdc7fa3, 0x22226644, 0x2a2a7e54,
-    0x9090ab3b, 0x8888830b, 0x4646ca8c, 0xeeee29c7, 0xb8b8d36b, 0x14143c28,
-    0xdede79a7, 0x5e5ee2bc, 0x0b0b1d16, 0xdbdb76ad, 0xe0e03bdb, 0x32325664,
-    0x3a3a4e74, 0x0a0a1e14, 0x4949db92, 0x06060a0c, 0x24246c48, 0x5c5ce4b8,
-    0xc2c25d9f, 0xd3d36ebd, 0xacacef43, 0x6262a6c4, 0x9191a839, 0x9595a431,
-    0xe4e437d3, 0x79798bf2, 0xe7e732d5, 0xc8c8438b, 0x3737596e, 0x6d6db7da,
-    0x8d8d8c01, 0xd5d564b1, 0x4e4ed29c, 0xa9a9e049, 0x6c6cb4d8, 0x5656faac,
-    0xf4f407f3, 0xeaea25cf, 0x6565afca, 0x7a7a8ef4, 0xaeaee947, 0x08081810,
-    0xbabad56f, 0x787888f0, 0x25256f4a, 0x2e2e725c, 0x1c1c2438, 0xa6a6f157,
-    0xb4b4c773, 0xc6c65197, 0xe8e823cb, 0xdddd7ca1, 0x74749ce8, 0x1f1f213e,
-    0x4b4bdd96, 0xbdbddc61, 0x8b8b860d, 0x8a8a850f, 0x707090e0, 0x3e3e427c,
-    0xb5b5c471, 0x6666aacc, 0x4848d890, 0x03030506, 0xf6f601f7, 0x0e0e121c,
-    0x6161a3c2, 0x35355f6a, 0x5757f9ae, 0xb9b9d069, 0x86869117, 0xc1c15899,
-    0x1d1d273a, 0x9e9eb927, 0xe1e138d9, 0xf8f813eb, 0x9898b32b, 0x11113322,
-    0x6969bbd2, 0xd9d970a9, 0x8e8e8907, 0x9494a733, 0x9b9bb62d, 0x1e1e223c,
-    0x87879215, 0xe9e920c9, 0xcece4987, 0x5555ffaa, 0x28287850, 0xdfdf7aa5,
-    0x8c8c8f03, 0xa1a1f859, 0x89898009, 0x0d0d171a, 0xbfbfda65, 0xe6e631d7,
-    0x4242c684, 0x6868b8d0, 0x4141c382, 0x9999b029, 0x2d2d775a, 0x0f0f111e,
-    0xb0b0cb7b, 0x5454fca8, 0xbbbbd66d, 0x16163a2c,
+    0xc6a56363, 0xf8847c7c, 0xee997777, 0xf68d7b7b, 0xff0df2f2, 0xd6bd6b6b,
+    0xdeb16f6f, 0x9154c5c5, 0x60503030, 0x02030101, 0xcea96767, 0x567d2b2b,
+    0xe719fefe, 0xb562d7d7, 0x4de6abab, 0xec9a7676, 0x8f45caca, 0x1f9d8282,
+    0x8940c9c9, 0xfa877d7d, 0xef15fafa, 0xb2eb5959, 0x8ec94747, 0xfb0bf0f0,
+    0x41ecadad, 0xb367d4d4, 0x5ffda2a2, 0x45eaafaf, 0x23bf9c9c, 0x53f7a4a4,
+    0xe4967272, 0x9b5bc0c0, 0x75c2b7b7, 0xe11cfdfd, 0x3dae9393, 0x4c6a2626,
+    0x6c5a3636, 0x7e413f3f, 0xf502f7f7, 0x834fcccc, 0x685c3434, 0x51f4a5a5,
+    0xd134e5e5, 0xf908f1f1, 0xe2937171, 0xab73d8d8, 0x62533131, 0x2a3f1515,
+    0x080c0404, 0x9552c7c7, 0x46652323, 0x9d5ec3c3, 0x30281818, 0x37a19696,
+    0x0a0f0505, 0x2fb59a9a, 0x0e090707, 0x24361212, 0x1b9b8080, 0xdf3de2e2,
+    0xcd26ebeb, 0x4e692727, 0x7fcdb2b2, 0xea9f7575, 0x121b0909, 0x1d9e8383,
+    0x58742c2c, 0x342e1a1a, 0x362d1b1b, 0xdcb26e6e, 0xb4ee5a5a, 0x5bfba0a0,
+    0xa4f65252, 0x764d3b3b, 0xb761d6d6, 0x7dceb3b3, 0x527b2929, 0xdd3ee3e3,
+    0x5e712f2f, 0x13978484, 0xa6f55353, 0xb968d1d1, 0x00000000, 0xc12ceded,
+    0x40602020, 0xe31ffcfc, 0x79c8b1b1, 0xb6ed5b5b, 0xd4be6a6a, 0x8d46cbcb,
+    0x67d9bebe, 0x724b3939, 0x94de4a4a, 0x98d44c4c, 0xb0e85858, 0x854acfcf,
+    0xbb6bd0d0, 0xc52aefef, 0x4fe5aaaa, 0xed16fbfb, 0x86c54343, 0x9ad74d4d,
+    0x66553333, 0x11948585, 0x8acf4545, 0xe910f9f9, 0x04060202, 0xfe817f7f,
+    0xa0f05050, 0x78443c3c, 0x25ba9f9f, 0x4be3a8a8, 0xa2f35151, 0x5dfea3a3,
+    0x80c04040, 0x058a8f8f, 0x3fad9292, 0x21bc9d9d, 0x70483838, 0xf104f5f5,
+    0x63dfbcbc, 0x77c1b6b6, 0xaf75dada, 0x42632121, 0x20301010, 0xe51affff,
+    0xfd0ef3f3, 0xbf6dd2d2, 0x814ccdcd, 0x18140c0c, 0x26351313, 0xc32fecec,
+    0xbee15f5f, 0x35a29797, 0x88cc4444, 0x2e391717, 0x9357c4c4, 0x55f2a7a7,
+    0xfc827e7e, 0x7a473d3d, 0xc8ac6464, 0xbae75d5d, 0x322b1919, 0xe6957373,
+    0xc0a06060, 0x19988181, 0x9ed14f4f, 0xa37fdcdc, 0x44662222, 0x547e2a2a,
+    0x3bab9090, 0x0b838888, 0x8cca4646, 0xc729eeee, 0x6bd3b8b8, 0x283c1414,
+    0xa779dede, 0xbce25e5e, 0x161d0b0b, 0xad76dbdb, 0xdb3be0e0, 0x64563232,
+    0x744e3a3a, 0x141e0a0a, 0x92db4949, 0x0c0a0606, 0x486c2424, 0xb8e45c5c,
+    0x9f5dc2c2, 0xbd6ed3d3, 0x43efacac, 0xc4a66262, 0x39a89191, 0x31a49595,
+    0xd337e4e4, 0xf28b7979, 0xd532e7e7, 0x8b43c8c8, 0x6e593737, 0xdab76d6d,
+    0x018c8d8d, 0xb164d5d5, 0x9cd24e4e, 0x49e0a9a9, 0xd8b46c6c, 0xacfa5656,
+    0xf307f4f4, 0xcf25eaea, 0xcaaf6565, 0xf48e7a7a, 0x47e9aeae, 0x10180808,
+    0x6fd5baba, 0xf0887878, 0x4a6f2525, 0x5c722e2e, 0x38241c1c, 0x57f1a6a6,
+    0x73c7b4b4, 0x9751c6c6, 0xcb23e8e8, 0xa17cdddd, 0xe89c7474, 0x3e211f1f,
+    0x96dd4b4b, 0x61dcbdbd, 0x0d868b8b, 0x0f858a8a, 0xe0907070, 0x7c423e3e,
+    0x71c4b5b5, 0xccaa6666, 0x90d84848, 0x06050303, 0xf701f6f6, 0x1c120e0e,
+    0xc2a36161, 0x6a5f3535, 0xaef95757, 0x69d0b9b9, 0x17918686, 0x9958c1c1,
+    0x3a271d1d, 0x27b99e9e, 0xd938e1e1, 0xeb13f8f8, 0x2bb39898, 0x22331111,
+    0xd2bb6969, 0xa970d9d9, 0x07898e8e, 0x33a79494, 0x2db69b9b, 0x3c221e1e,
+    0x15928787, 0xc920e9e9, 0x8749cece, 0xaaff5555, 0x50782828, 0xa57adfdf,
+    0x038f8c8c, 0x59f8a1a1, 0x09808989, 0x1a170d0d, 0x65dabfbf, 0xd731e6e6,
+    0x84c64242, 0xd0b86868, 0x82c34141, 0x29b09999, 0x5a772d2d, 0x1e110f0f,
+    0x7bcbb0b0, 0xa8fc5454, 0x6dd6bbbb, 0x2c3a1616,
 };
 
 // Software implementation of the Vector128 class, using uint32_t
@@ -235,45 +237,13 @@ struct alignas(16) Vector128 {
 inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE Vector128
 Vector128Load(const void* from) {
   Vector128 result;
-  const uint8_t* src = reinterpret_cast<const uint8_t*>(from);
-  result.s[0] = static_cast<uint32_t>(src[0]) << 24 |
-                static_cast<uint32_t>(src[1]) << 16 |
-                static_cast<uint32_t>(src[2]) << 8 |
-                static_cast<uint32_t>(src[3]);
-  result.s[1] = static_cast<uint32_t>(src[4]) << 24 |
-                static_cast<uint32_t>(src[5]) << 16 |
-                static_cast<uint32_t>(src[6]) << 8 |
-                static_cast<uint32_t>(src[7]);
-  result.s[2] = static_cast<uint32_t>(src[8]) << 24 |
-                static_cast<uint32_t>(src[9]) << 16 |
-                static_cast<uint32_t>(src[10]) << 8 |
-                static_cast<uint32_t>(src[11]);
-  result.s[3] = static_cast<uint32_t>(src[12]) << 24 |
-                static_cast<uint32_t>(src[13]) << 16 |
-                static_cast<uint32_t>(src[14]) << 8 |
-                static_cast<uint32_t>(src[15]);
+  std::memcpy(result.s, from, sizeof(Vector128));
   return result;
 }
 
 inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void Vector128Store(
     const Vector128& v, void* to) {
-  uint8_t* dst = reinterpret_cast<uint8_t*>(to);
-  dst[0] = static_cast<uint8_t>(v.s[0] >> 24);
-  dst[1] = static_cast<uint8_t>(v.s[0] >> 16);
-  dst[2] = static_cast<uint8_t>(v.s[0] >> 8);
-  dst[3] = static_cast<uint8_t>(v.s[0]);
-  dst[4] = static_cast<uint8_t>(v.s[1] >> 24);
-  dst[5] = static_cast<uint8_t>(v.s[1] >> 16);
-  dst[6] = static_cast<uint8_t>(v.s[1] >> 8);
-  dst[7] = static_cast<uint8_t>(v.s[1]);
-  dst[8] = static_cast<uint8_t>(v.s[2] >> 24);
-  dst[9] = static_cast<uint8_t>(v.s[2] >> 16);
-  dst[10] = static_cast<uint8_t>(v.s[2] >> 8);
-  dst[11] = static_cast<uint8_t>(v.s[2]);
-  dst[12] = static_cast<uint8_t>(v.s[3] >> 24);
-  dst[13] = static_cast<uint8_t>(v.s[3] >> 16);
-  dst[14] = static_cast<uint8_t>(v.s[3] >> 8);
-  dst[15] = static_cast<uint8_t>(v.s[3]);
+  std::memcpy(to, v.s, sizeof(Vector128));
 }
 
 // One round of AES. "round_key" is a public constant for breaking the
@@ -282,38 +252,33 @@ inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE Vector128
 AesRound(const Vector128& state, const Vector128& round_key) {
   Vector128 result;
   result.s[0] = round_key.s[0] ^                  //
-                te0[uint8_t(state.s[0] >> 24)] ^  //
-                te1[uint8_t(state.s[1] >> 16)] ^  //
-                te2[uint8_t(state.s[2] >> 8)] ^   //
-                te3[uint8_t(state.s[3])];
+                te0[uint8_t(state.s[0])] ^        //
+                te1[uint8_t(state.s[1] >> 8)] ^   //
+                te2[uint8_t(state.s[2] >> 16)] ^  //
+                te3[uint8_t(state.s[3] >> 24)];
   result.s[1] = round_key.s[1] ^                  //
-                te0[uint8_t(state.s[1] >> 24)] ^  //
-                te1[uint8_t(state.s[2] >> 16)] ^  //
-                te2[uint8_t(state.s[3] >> 8)] ^   //
-                te3[uint8_t(state.s[0])];
+                te0[uint8_t(state.s[1])] ^        //
+                te1[uint8_t(state.s[2] >> 8)] ^   //
+                te2[uint8_t(state.s[3] >> 16)] ^  //
+                te3[uint8_t(state.s[0] >> 24)];
   result.s[2] = round_key.s[2] ^                  //
-                te0[uint8_t(state.s[2] >> 24)] ^  //
-                te1[uint8_t(state.s[3] >> 16)] ^  //
-                te2[uint8_t(state.s[0] >> 8)] ^   //
-                te3[uint8_t(state.s[1])];
+                te0[uint8_t(state.s[2])] ^        //
+                te1[uint8_t(state.s[3] >> 8)] ^   //
+                te2[uint8_t(state.s[0] >> 16)] ^  //
+                te3[uint8_t(state.s[1] >> 24)];
   result.s[3] = round_key.s[3] ^                  //
-                te0[uint8_t(state.s[3] >> 24)] ^  //
-                te1[uint8_t(state.s[0] >> 16)] ^  //
-                te2[uint8_t(state.s[1] >> 8)] ^   //
-                te3[uint8_t(state.s[2])];
+                te0[uint8_t(state.s[3])] ^        //
+                te1[uint8_t(state.s[0] >> 8)] ^   //
+                te2[uint8_t(state.s[1] >> 16)] ^  //
+                te3[uint8_t(state.s[2] >> 24)];
   return result;
 }
 
 using ::absl::random_internal::RandenTraits;
 
-// Randen operates on 128-bit vectors.
-struct alignas(16) u64x2 {
-  uint64_t data[2];
-};
-
 // The improved Feistel block shuffle function for 16 blocks.
 inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void BlockShuffle(
-    u64x2* state) {
+    absl::uint128* state) {
   static_assert(RandenTraits::kFeistelBlocks == 16,
                 "Feistel block shuffle only works for 16 blocks.");
 
@@ -323,31 +288,31 @@ inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void BlockShuffle(
   // The fully unrolled loop without the memcpy improves the speed by about
   // 30% over the equivalent:
 #if 0
-  u64x2 source[RandenTraits::kFeistelBlocks];
+  absl::uint128 source[RandenTraits::kFeistelBlocks];
   std::memcpy(source, state, sizeof(source));
   for (size_t i = 0; i < RandenTraits::kFeistelBlocks; i++) {
-    const u64x2 v0 = source[shuffle[i]];
+    const absl::uint128 v0 = source[shuffle[i]];
     state[i] = v0;
   }
   return;
 #endif
 
-  const u64x2 v0 = state[shuffle[0]];
-  const u64x2 v1 = state[shuffle[1]];
-  const u64x2 v2 = state[shuffle[2]];
-  const u64x2 v3 = state[shuffle[3]];
-  const u64x2 v4 = state[shuffle[4]];
-  const u64x2 v5 = state[shuffle[5]];
-  const u64x2 v6 = state[shuffle[6]];
-  const u64x2 v7 = state[shuffle[7]];
-  const u64x2 w0 = state[shuffle[8]];
-  const u64x2 w1 = state[shuffle[9]];
-  const u64x2 w2 = state[shuffle[10]];
-  const u64x2 w3 = state[shuffle[11]];
-  const u64x2 w4 = state[shuffle[12]];
-  const u64x2 w5 = state[shuffle[13]];
-  const u64x2 w6 = state[shuffle[14]];
-  const u64x2 w7 = state[shuffle[15]];
+  const absl::uint128 v0 = state[shuffle[0]];
+  const absl::uint128 v1 = state[shuffle[1]];
+  const absl::uint128 v2 = state[shuffle[2]];
+  const absl::uint128 v3 = state[shuffle[3]];
+  const absl::uint128 v4 = state[shuffle[4]];
+  const absl::uint128 v5 = state[shuffle[5]];
+  const absl::uint128 v6 = state[shuffle[6]];
+  const absl::uint128 v7 = state[shuffle[7]];
+  const absl::uint128 w0 = state[shuffle[8]];
+  const absl::uint128 w1 = state[shuffle[9]];
+  const absl::uint128 w2 = state[shuffle[10]];
+  const absl::uint128 w3 = state[shuffle[11]];
+  const absl::uint128 w4 = state[shuffle[12]];
+  const absl::uint128 w5 = state[shuffle[13]];
+  const absl::uint128 w6 = state[shuffle[14]];
+  const absl::uint128 w7 = state[shuffle[15]];
   state[0] = v0;
   state[1] = v1;
   state[2] = v2;
@@ -371,9 +336,9 @@ inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void BlockShuffle(
 // per 16 bytes (vs. 10 for AES-CTR). Computing eight round functions in
 // parallel hides the 7-cycle AESNI latency on HSW. Note that the Feistel
 // XORs are 'free' (included in the second AES instruction).
-inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE const u64x2* FeistelRound(
-    u64x2* ABSL_RANDOM_INTERNAL_RESTRICT state,
-    const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
+inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE const absl::uint128*
+FeistelRound(absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT state,
+             const absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
   for (size_t branch = 0; branch < RandenTraits::kFeistelBlocks; branch += 4) {
     const Vector128 s0 = Vector128Load(state + branch);
     const Vector128 s1 = Vector128Load(state + branch + 1);
@@ -398,7 +363,8 @@ inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE const u64x2* FeistelRound(
 // 2^64 queries if the round function is a PRF. This is similar to the b=8 case
 // of Simpira v2, but more efficient than its generic construction for b=16.
 inline ABSL_RANDOM_INTERNAL_ATTRIBUTE_ALWAYS_INLINE void Permute(
-    u64x2* state, const u64x2* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
+    absl::uint128* state,
+    const absl::uint128* ABSL_RANDOM_INTERNAL_RESTRICT keys) {
   for (size_t round = 0; round < RandenTraits::kFeistelRounds; ++round) {
     keys = FeistelRound(state, keys);
     BlockShuffle(state);
@@ -437,19 +403,18 @@ void RandenSlow::Absorb(const void* seed_void, void* state_void) {
 }
 
 void RandenSlow::Generate(const void* keys_void, void* state_void) {
-  static_assert(RandenTraits::kCapacityBytes == sizeof(u64x2),
+  static_assert(RandenTraits::kCapacityBytes == sizeof(absl::uint128),
                 "Capacity mismatch");
 
-  auto* state = reinterpret_cast<u64x2*>(state_void);
-  const auto* keys = reinterpret_cast<const u64x2*>(keys_void);
+  auto* state = reinterpret_cast<absl::uint128*>(state_void);
+  const auto* keys = reinterpret_cast<const absl::uint128*>(keys_void);
 
-  const u64x2 prev_inner = state[0];
+  const absl::uint128 prev_inner = state[0];
 
   Permute(state, keys);
 
   // Ensure backtracking resistance.
-  state[0].data[0] ^= prev_inner.data[0];
-  state[0].data[1] ^= prev_inner.data[1];
+  *state ^= prev_inner;
 }
 
 }  // namespace random_internal
diff --git a/absl/strings/cord_ring_test.cc b/absl/strings/cord_ring_test.cc
index cc8fbaf9..b1787edf 100644
--- a/absl/strings/cord_ring_test.cc
+++ b/absl/strings/cord_ring_test.cc
@@ -223,7 +223,7 @@ CordRepExternal* MakeFakeExternal(size_t length) {
     std::string s;
     explicit Rep(size_t len) {
       this->tag = EXTERNAL;
-      this->base = this->storage;
+      this->base = reinterpret_cast<const char*>(this->storage);
       this->length = len;
       this->releaser_invoker = [](CordRepExternal* self) {
         delete static_cast<Rep*>(self);
diff --git a/absl/strings/internal/cord_internal.cc b/absl/strings/internal/cord_internal.cc
index 905ffd0c..6a0b051c 100644
--- a/absl/strings/internal/cord_internal.cc
+++ b/absl/strings/internal/cord_internal.cc
@@ -25,6 +25,7 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace cord_internal {
 
+ABSL_CONST_INIT std::atomic<bool> cord_btree_enabled(kCordEnableBtreeDefault);
 ABSL_CONST_INIT std::atomic<bool> cord_ring_buffer_enabled(
     kCordEnableRingBufferDefault);
 ABSL_CONST_INIT std::atomic<bool> shallow_subcords_enabled(
diff --git a/absl/strings/internal/cord_internal.h b/absl/strings/internal/cord_internal.h
index bddc9815..371a7f9c 100644
--- a/absl/strings/internal/cord_internal.h
+++ b/absl/strings/internal/cord_internal.h
@@ -37,13 +37,19 @@ class CordzInfo;
 
 // Default feature enable states for cord ring buffers
 enum CordFeatureDefaults {
+  kCordEnableBtreeDefault = false,
   kCordEnableRingBufferDefault = false,
   kCordShallowSubcordsDefault = false
 };
 
+extern std::atomic<bool> cord_btree_enabled;
 extern std::atomic<bool> cord_ring_buffer_enabled;
 extern std::atomic<bool> shallow_subcords_enabled;
 
+inline void enable_cord_btree(bool enable) {
+  cord_btree_enabled.store(enable, std::memory_order_relaxed);
+}
+
 inline void enable_cord_ring_buffer(bool enable) {
   cord_ring_buffer_enabled.store(enable, std::memory_order_relaxed);
 }
@@ -193,7 +199,16 @@ struct CordRep {
   // If tag < FLAT, it represents CordRepKind and indicates the type of node.
   // Otherwise, the node type is CordRepFlat and the tag is the encoded size.
   uint8_t tag;
-  char storage[1];  // Starting point for flat array: MUST BE LAST FIELD
+
+  // `storage` provides two main purposes:
+  // - the starting point for FlatCordRep.Data() [flexible-array-member]
+  // - 3 bytes of additional storage for use by derived classes.
+  // The latter is used by CordrepConcat and CordRepBtree. CordRepConcat stores
+  // a 'depth' value in storage[0], and the (future) CordRepBtree class stores
+  // `height`, `begin` and `end` in the 3 entries. Otherwise we would need to
+  // allocate room for these in the derived class, as not all compilers reuse
+  // padding space from the base class (clang and gcc do, MSVC does not, etc)
+  uint8_t storage[3];
 
   inline CordRepRing* ring();
   inline const CordRepRing* ring() const;
@@ -228,8 +243,8 @@ struct CordRepConcat : public CordRep {
   CordRep* left;
   CordRep* right;
 
-  uint8_t depth() const { return static_cast<uint8_t>(storage[0]); }
-  void set_depth(uint8_t depth) { storage[0] = static_cast<char>(depth); }
+  uint8_t depth() const { return storage[0]; }
+  void set_depth(uint8_t depth) { storage[0] = depth; }
 };
 
 struct CordRepSubstring : public CordRep {
diff --git a/absl/strings/internal/cord_rep_flat.h b/absl/strings/internal/cord_rep_flat.h
index cddb282f..4d0f9886 100644
--- a/absl/strings/internal/cord_rep_flat.h
+++ b/absl/strings/internal/cord_rep_flat.h
@@ -118,8 +118,8 @@ struct CordRepFlat : public CordRep {
   }
 
   // Returns a pointer to the data inside this flat rep.
-  char* Data() { return storage; }
-  const char* Data() const { return storage; }
+  char* Data() { return reinterpret_cast<char*>(storage); }
+  const char* Data() const { return reinterpret_cast<const char*>(storage); }
 
   // Returns the maximum capacity (payload size) of this instance.
   size_t Capacity() const { return TagToLength(tag); }
diff --git a/absl/strings/str_format.h b/absl/strings/str_format.h
index 01465107..4b05c70c 100644
--- a/absl/strings/str_format.h
+++ b/absl/strings/str_format.h
@@ -536,8 +536,7 @@ using FormatArg = str_format_internal::FormatArgImpl;
 // The arguments are provided in an `absl::Span<const absl::FormatArg>`.
 // Each `absl::FormatArg` object binds to a single argument and keeps a
 // reference to it. The values used to create the `FormatArg` objects must
-// outlive this function call. (See `str_format_arg.h` for information on
-// the `FormatArg` class.)_
+// outlive this function call.
 //
 // Example:
 //