Adding upstream version 3.8.1.upstream/3.8.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 2003 insertions, 0 deletions

diff --git a/contrib/t1ha/CMakeLists.txt b/contrib/t1ha/CMakeLists.txt
new file mode 100644
index 0000000..c8de483
--- /dev/null
+++ b/contrib/t1ha/CMakeLists.txt
@@ -0,0 +1,6 @@
+SET(T1HASRC     t1ha1.c
+                t1ha2.c)
+
+ADD_LIBRARY(rspamd-t1ha STATIC ${T1HASRC})
+SET_TARGET_PROPERTIES(rspamd-t1ha PROPERTIES VERSION ${RSPAMD_VERSION})
+ADD_DEFINITIONS("-DT1HA_USE_FAST_ONESHOT_READ=0")
diff --git a/contrib/t1ha/LICENSE b/contrib/t1ha/LICENSE
new file mode 100644
index 0000000..d02db65
--- /dev/null
+++ b/contrib/t1ha/LICENSE
@@ -0,0 +1,21 @@
+ Copyright (c) 2016-2018 Positive Technologies, https://www.ptsecurity.com,
+ Fast Positive Hash.
+
+ Portions Copyright (c) 2010-2013 Leonid Yuriev <leo@yuriev.ru>,
+ The 1Hippeus project (t1h).
+
+ This software is provided 'as-is', without any express or implied
+ warranty. In no event will the authors be held liable for any damages
+ arising from the use of this software.
+
+ Permission is granted to anyone to use this software for any purpose,
+ including commercial applications, and to alter it and redistribute it
+ freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must not
+    claim that you wrote the original software. If you use this software
+    in a product, an acknowledgement in the product documentation would be
+    appreciated but is not required.
+ 2. Altered source versions must be plainly marked as such, and must not be
+    misrepresented as being the original software.
+ 3. This notice may not be removed or altered from any source distribution.
diff --git a/contrib/t1ha/t1ha.h b/contrib/t1ha/t1ha.h
new file mode 100644
index 0000000..e5f2dad
--- /dev/null
+++ b/contrib/t1ha/t1ha.h
@@ -0,0 +1,321 @@
+/*
+ *  Copyright (c) 2016-2018 Positive Technologies, https://www.ptsecurity.com,
+ *  Fast Positive Hash.
+ *
+ *  Portions Copyright (c) 2010-2018 Leonid Yuriev <leo@yuriev.ru>,
+ *  The 1Hippeus project (t1h).
+ *
+ *  This software is provided 'as-is', without any express or implied
+ *  warranty. In no event will the authors be held liable for any damages
+ *  arising from the use of this software.
+ *
+ *  Permission is granted to anyone to use this software for any purpose,
+ *  including commercial applications, and to alter it and redistribute it
+ *  freely, subject to the following restrictions:
+ *
+ *  1. The origin of this software must not be misrepresented; you must not
+ *     claim that you wrote the original software. If you use this software
+ *     in a product, an acknowledgement in the product documentation would be
+ *     appreciated but is not required.
+ *  2. Altered source versions must be plainly marked as such, and must not be
+ *     misrepresented as being the original software.
+ *  3. This notice may not be removed or altered from any source distribution.
+ */
+
+/*
+ * t1ha = { Fast Positive Hash, aka "Позитивный Хэш" }
+ * by [Positive Technologies](https://www.ptsecurity.ru)
+ *
+ * Briefly, it is a 64-bit Hash Function:
+ *  1. Created for 64-bit little-endian platforms, in predominantly for x86_64,
+ *     but portable and without penalties it can run on any 64-bit CPU.
+ *  2. In most cases up to 15% faster than City64, xxHash, mum-hash, metro-hash
+ *     and all others portable hash-functions (which do not use specific
+ *     hardware tricks).
+ *  3. Not suitable for cryptography.
+ *
+ * The Future will Positive. Всё будет хорошо.
+ *
+ * ACKNOWLEDGEMENT:
+ * The t1ha was originally developed by Leonid Yuriev (Леонид Юрьев)
+ * for The 1Hippeus project - zerocopy messaging in the spirit of Sparta!
+ */
+
+#pragma once
+
+#ifndef __has_attribute
+#define __has_attribute(x) (0)
+#endif
+
+#ifndef __has_include
+#define __has_include(x) (0)
+#endif
+
+#ifndef __GNUC_PREREQ
+#if defined(__GNUC__) && defined(__GNUC_MINOR__)
+#define __GNUC_PREREQ(maj, min)                                                \
+  ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+#else
+#define __GNUC_PREREQ(maj, min) 0
+#endif
+#endif /* __GNUC_PREREQ */
+
+#ifndef __CLANG_PREREQ
+#ifdef __clang__
+#define __CLANG_PREREQ(maj, min)                                               \
+  ((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))
+#else
+#define __CLANG_PREREQ(maj, min) (0)
+#endif
+#endif /* __CLANG_PREREQ */
+
+/*****************************************************************************/
+
+#ifdef _MSC_VER
+/* Avoid '16' bytes padding added after data member 't1ha_context::total'
+ * and other warnings from std-headers if warning-level > 3. */
+#pragma warning(push, 3)
+#endif
+
+#if defined(__cplusplus) && __cplusplus >= 201103L
+#include <climits>
+#include <cstddef>
+#include <cstdint>
+#else
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+#endif
+
+/*****************************************************************************/
+
+#if defined(i386) || defined(__386) || defined(__i386) || defined(__i386__) || \
+    defined(i486) || defined(__i486) || defined(__i486__) ||                   \
+    defined(i586) | defined(__i586) || defined(__i586__) || defined(i686) ||   \
+    defined(__i686) || defined(__i686__) || defined(_M_IX86) ||                \
+    defined(_X86_) || defined(__THW_INTEL__) || defined(__I86__) ||            \
+    defined(__INTEL__) || defined(__x86_64) || defined(__x86_64__) ||          \
+    defined(__amd64__) || defined(__amd64) || defined(_M_X64) ||               \
+    defined(_M_AMD64) || defined(__IA32__) || defined(__INTEL__)
+#ifndef __ia32__
+/* LY: define neutral __ia32__ for x86 and x86-64 archs */
+#define __ia32__ 1
+#endif /* __ia32__ */
+#if !defined(__amd64__) && (defined(__x86_64) || defined(__x86_64__) ||        \
+                            defined(__amd64) || defined(_M_X64))
+/* LY: define trusty __amd64__ for all AMD64/x86-64 arch */
+#define __amd64__ 1
+#endif /* __amd64__ */
+#endif /* all x86 */
+
+#if !defined(__BYTE_ORDER__) || !defined(__ORDER_LITTLE_ENDIAN__) ||           \
+    !defined(__ORDER_BIG_ENDIAN__)
+
+/* *INDENT-OFF* */
+/* clang-format off */
+
+#if defined(__GLIBC__) || defined(__GNU_LIBRARY__) || defined(__ANDROID__) ||  \
+    defined(HAVE_ENDIAN_H) || __has_include(<endian.h>)
+#include <endian.h>
+#elif defined(__APPLE__) || defined(__MACH__) || defined(__OpenBSD__) ||       \
+    defined(HAVE_MACHINE_ENDIAN_H) || __has_include(<machine/endian.h>)
+#include <machine/endian.h>
+#elif defined(HAVE_SYS_ISA_DEFS_H) || __has_include(<sys/isa_defs.h>)
+#include <sys/isa_defs.h>
+#elif (defined(HAVE_SYS_TYPES_H) && defined(HAVE_SYS_ENDIAN_H)) ||             \
+    (__has_include(<sys/types.h>) && __has_include(<sys/endian.h>))
+#include <sys/endian.h>
+#include <sys/types.h>
+#elif defined(__bsdi__) || defined(__DragonFly__) || defined(__FreeBSD__) ||   \
+    defined(__NETBSD__) || defined(__NetBSD__) ||                              \
+    defined(HAVE_SYS_PARAM_H) || __has_include(<sys/param.h>)
+#include <sys/param.h>
+#endif /* OS */
+
+/* *INDENT-ON* */
+/* clang-format on */
+
+#if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN)
+#define __ORDER_LITTLE_ENDIAN__ __LITTLE_ENDIAN
+#define __ORDER_BIG_ENDIAN__ __BIG_ENDIAN
+#define __BYTE_ORDER__ __BYTE_ORDER
+#elif defined(_BYTE_ORDER) && defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)
+#define __ORDER_LITTLE_ENDIAN__ _LITTLE_ENDIAN
+#define __ORDER_BIG_ENDIAN__ _BIG_ENDIAN
+#define __BYTE_ORDER__ _BYTE_ORDER
+#else
+#define __ORDER_LITTLE_ENDIAN__ 1234
+#define __ORDER_BIG_ENDIAN__ 4321
+
+#if defined(__LITTLE_ENDIAN__) ||                                              \
+    (defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN)) ||                      \
+    defined(__ARMEL__) || defined(__THUMBEL__) || defined(__AARCH64EL__) ||    \
+    defined(__MIPSEL__) || defined(_MIPSEL) || defined(__MIPSEL) ||            \
+    defined(_M_ARM) || defined(_M_ARM64) || defined(__e2k__) ||                \
+    defined(__elbrus_4c__) || defined(__elbrus_8c__) || defined(__bfin__) ||   \
+    defined(__BFIN__) || defined(__ia64__) || defined(_IA64) ||                \
+    defined(__IA64__) || defined(__ia64) || defined(_M_IA64) ||                \
+    defined(__itanium__) || defined(__ia32__) || defined(__CYGWIN__) ||        \
+    defined(_WIN64) || defined(_WIN32) || defined(__TOS_WIN__) ||              \
+    defined(__WINDOWS__)
+#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
+
+#elif defined(__BIG_ENDIAN__) ||                                               \
+    (defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)) ||                      \
+    defined(__ARMEB__) || defined(__THUMBEB__) || defined(__AARCH64EB__) ||    \
+    defined(__MIPSEB__) || defined(_MIPSEB) || defined(__MIPSEB) ||            \
+    defined(__m68k__) || defined(M68000) || defined(__hppa__) ||               \
+    defined(__hppa) || defined(__HPPA__) || defined(__sparc__) ||              \
+    defined(__sparc) || defined(__370__) || defined(__THW_370__) ||            \
+    defined(__s390__) || defined(__s390x__) || defined(__SYSC_ZARCH__)
+#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
+
+#else
+#error __BYTE_ORDER__ should be defined.
+#endif /* Arch */
+
+#endif
+#endif /* __BYTE_ORDER__ || __ORDER_LITTLE_ENDIAN__ || __ORDER_BIG_ENDIAN__ */
+
+/*****************************************************************************/
+
+#ifndef __dll_export
+#if defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__)
+#if defined(__GNUC__) || __has_attribute(dllexport)
+#define __dll_export __attribute__((dllexport))
+#elif defined(_MSC_VER)
+#define __dll_export __declspec(dllexport)
+#else
+#define __dll_export
+#endif
+#elif defined(__GNUC__) || __has_attribute(visibility)
+#define __dll_export __attribute__((visibility("default")))
+#else
+#define __dll_export
+#endif
+#endif /* __dll_export */
+
+#ifndef __dll_import
+#if defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__)
+#if defined(__GNUC__) || __has_attribute(dllimport)
+#define __dll_import __attribute__((dllimport))
+#elif defined(_MSC_VER)
+#define __dll_import __declspec(dllimport)
+#else
+#define __dll_import
+#endif
+#else
+#define __dll_import
+#endif
+#endif /* __dll_import */
+
+#if defined(t1ha_EXPORTS)
+#define T1HA_API __dll_export
+#elif defined(t1ha_IMPORTS)
+#define T1HA_API __dll_import
+#else
+#define T1HA_API
+#endif /* T1HA_API */
+
+#define T1HA_ALIGN_PREFIX
+#define T1HA_ALIGN_SUFFIX
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef union T1HA_ALIGN_PREFIX t1ha_state256 {
+  uint8_t bytes[32];
+  uint32_t u32[8];
+  uint64_t u64[4];
+  struct {
+    uint64_t a, b, c, d;
+  } n;
+} t1ha_state256_t T1HA_ALIGN_SUFFIX;
+
+typedef struct t1ha_context {
+  t1ha_state256_t state;
+  t1ha_state256_t buffer;
+  size_t partial;
+  uint64_t total;
+} t1ha_context_t;
+
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+/******************************************************************************
+ *
+ *  t1ha2 = 64 and 128-bit, SLIGHTLY MORE ATTENTION FOR QUALITY AND STRENGTH.
+ *
+ *    - The recommended version of "Fast Positive Hash" with good quality
+ *      for checksum, hash tables and fingerprinting.
+ *    - Portable and extremely efficiency on modern 64-bit CPUs.
+ *      Designed for 64-bit little-endian platforms,
+ *      in other cases will runs slowly.
+ *    - Great quality of hashing and still faster than other non-t1ha hashes.
+ *      Provides streaming mode and 128-bit result.
+ *
+ * Note: Due performance reason 64- and 128-bit results are completely
+ *       different each other, i.e. 64-bit result is NOT any part of 128-bit.
+ */
+
+/* The at-once variant with 64-bit result */
+T1HA_API uint64_t t1ha2_atonce(const void *data, size_t length, uint64_t seed);
+
+/* The at-once variant with 128-bit result.
+ * Argument `extra_result` is NOT optional and MUST be valid.
+ * The high 64-bit part of 128-bit hash will be always unconditionally
+ * stored to the address given by `extra_result` argument. */
+T1HA_API uint64_t t1ha2_atonce128(uint64_t *__restrict extra_result,
+                                  const void *__restrict data, size_t length,
+                                  uint64_t seed);
+
+/* The init/update/final trinity for streaming.
+ * Return 64 or 128-bit result depentently from `extra_result` argument. */
+T1HA_API void t1ha2_init(t1ha_context_t *ctx, uint64_t seed_x, uint64_t seed_y);
+T1HA_API void t1ha2_update(t1ha_context_t *__restrict ctx,
+                           const void *__restrict data, size_t length);
+
+/* Argument `extra_result` is optional and MAY be NULL.
+ *  - If `extra_result` is NOT NULL then the 128-bit hash will be calculated,
+ *    and high 64-bit part of it will be stored to the address given
+ *    by `extra_result` argument.
+ *  - Otherwise the 64-bit hash will be calculated
+ *    and returned from function directly.
+ *
+ * Note: Due performance reason 64- and 128-bit results are completely
+ *       different each other, i.e. 64-bit result is NOT any part of 128-bit. */
+T1HA_API uint64_t t1ha2_final(t1ha_context_t *__restrict ctx,
+                              uint64_t *__restrict extra_result /* optional */);
+
+/******************************************************************************
+ *
+ *  t1ha1 = 64-bit, BASELINE FAST PORTABLE HASH:
+ *
+ *    - Runs faster on 64-bit platforms in other cases may runs slowly.
+ *    - Portable and stable, returns same 64-bit result
+ *      on all architectures and CPUs.
+ *    - Unfortunately it fails the "strict avalanche criteria",
+ *      see test results at https://github.com/demerphq/smhasher.
+ *
+ *      This flaw is insignificant for the t1ha1() purposes and imperceptible
+ *      from a practical point of view.
+ *      However, nowadays this issue has resolved in the next t1ha2(),
+ *      that was initially planned to providing a bit more quality.
+ */
+
+/* The little-endian variant. */
+T1HA_API uint64_t t1ha1_le(const void *data, size_t length, uint64_t seed);
+
+/* The big-endian variant. */
+T1HA_API uint64_t t1ha1_be(const void *data, size_t length, uint64_t seed);
+
+/* The historical nicname for generic little-endian variant. */
+static __inline uint64_t t1ha(const void *data, size_t length, uint64_t seed) {
+  return t1ha1_le(data, length, seed);
+}
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/contrib/t1ha/t1ha1.c b/contrib/t1ha/t1ha1.c
new file mode 100644
index 0000000..6e25d37
--- /dev/null
+++ b/contrib/t1ha/t1ha1.c
@@ -0,0 +1,158 @@
+/*
+ *  Copyright (c) 2016-2018 Positive Technologies, https://www.ptsecurity.com,
+ *  Fast Positive Hash.
+ *
+ *  Portions Copyright (c) 2010-2018 Leonid Yuriev <leo@yuriev.ru>,
+ *  The 1Hippeus project (t1h).
+ *
+ *  This software is provided 'as-is', without any express or implied
+ *  warranty. In no event will the authors be held liable for any damages
+ *  arising from the use of this software.
+ *
+ *  Permission is granted to anyone to use this software for any purpose,
+ *  including commercial applications, and to alter it and redistribute it
+ *  freely, subject to the following restrictions:
+ *
+ *  1. The origin of this software must not be misrepresented; you must not
+ *     claim that you wrote the original software. If you use this software
+ *     in a product, an acknowledgement in the product documentation would be
+ *     appreciated but is not required.
+ *  2. Altered source versions must be plainly marked as such, and must not be
+ *     misrepresented as being the original software.
+ *  3. This notice may not be removed or altered from any source distribution.
+ */
+
+/*
+ * t1ha = { Fast Positive Hash, aka "Позитивный Хэш" }
+ * by [Positive Technologies](https://www.ptsecurity.ru)
+ *
+ * Briefly, it is a 64-bit Hash Function:
+ *  1. Created for 64-bit little-endian platforms, in predominantly for x86_64,
+ *     but portable and without penalties it can run on any 64-bit CPU.
+ *  2. In most cases up to 15% faster than City64, xxHash, mum-hash, metro-hash
+ *     and all others portable hash-functions (which do not use specific
+ *     hardware tricks).
+ *  3. Not suitable for cryptography.
+ *
+ * The Future will Positive. Всё будет хорошо.
+ *
+ * ACKNOWLEDGEMENT:
+ * The t1ha was originally developed by Leonid Yuriev (Леонид Юрьев)
+ * for The 1Hippeus project - zerocopy messaging in the spirit of Sparta!
+ */
+
+#include "config.h"
+#include "t1ha_bits.h"
+
+/* xor-mul-xor mixer */
+static __inline uint64_t mix64(uint64_t v, uint64_t p) {
+  v *= p;
+  return v ^ rot64(v, 41);
+}
+
+static __inline uint64_t final_weak_avalanche(uint64_t a, uint64_t b) {
+  /* LY: for performance reason on a some not high-end CPUs
+   * I replaced the second mux64() operation by mix64().
+   * Unfortunately this approach fails the "strict avalanche criteria",
+   * see test results at https://github.com/demerphq/smhasher. */
+  return mux64(rot64(a + b, 17), prime_4) + mix64(a ^ b, prime_0);
+}
+
+/* TODO: C++ template in the next version */
+#define T1HA1_BODY(ENDIANNES, ALIGNESS)                                        \
+  const uint64_t *v = (const uint64_t *)data;                                  \
+  if (unlikely(len > 32)) {                                                    \
+    uint64_t c = rot64(len, 17) + seed;                                        \
+    uint64_t d = len ^ rot64(seed, 17);                                        \
+    const uint64_t *detent =                                                   \
+        (const uint64_t *)((const uint8_t *)data + len - 31);                  \
+    do {                                                                       \
+      const uint64_t w0 = fetch64_##ENDIANNES##_##ALIGNESS(v + 0);             \
+      const uint64_t w1 = fetch64_##ENDIANNES##_##ALIGNESS(v + 1);             \
+      const uint64_t w2 = fetch64_##ENDIANNES##_##ALIGNESS(v + 2);             \
+      const uint64_t w3 = fetch64_##ENDIANNES##_##ALIGNESS(v + 3);             \
+      v += 4;                                                                  \
+      prefetch(v);                                                             \
+                                                                               \
+      const uint64_t d02 = w0 ^ rot64(w2 + d, 17);                             \
+      const uint64_t c13 = w1 ^ rot64(w3 + c, 17);                             \
+      c += a ^ rot64(w0, 41);                                                  \
+      d -= b ^ rot64(w1, 31);                                                  \
+      a ^= prime_1 * (d02 + w3);                                               \
+      b ^= prime_0 * (c13 + w2);                                               \
+    } while (likely(v < detent));                                              \
+                                                                               \
+    a ^= prime_6 * (rot64(c, 17) + d);                                         \
+    b ^= prime_5 * (c + rot64(d, 17));                                         \
+    len &= 31;                                                                 \
+  }                                                                            \
+                                                                               \
+  switch (len) {                                                               \
+  default:                                                                     \
+    b += mux64(fetch64_##ENDIANNES##_##ALIGNESS(v++), prime_4);                \
+  /* fall through */                                                           \
+  case 24:                                                                     \
+  case 23:                                                                     \
+  case 22:                                                                     \
+  case 21:                                                                     \
+  case 20:                                                                     \
+  case 19:                                                                     \
+  case 18:                                                                     \
+  case 17:                                                                     \
+    a += mux64(fetch64_##ENDIANNES##_##ALIGNESS(v++), prime_3);                \
+  /* fall through */                                                           \
+  case 16:                                                                     \
+  case 15:                                                                     \
+  case 14:                                                                     \
+  case 13:                                                                     \
+  case 12:                                                                     \
+  case 11:                                                                     \
+  case 10:                                                                     \
+  case 9:                                                                      \
+    b += mux64(fetch64_##ENDIANNES##_##ALIGNESS(v++), prime_2);                \
+  /* fall through */                                                           \
+  case 8:                                                                      \
+  case 7:                                                                      \
+  case 6:                                                                      \
+  case 5:                                                                      \
+  case 4:                                                                      \
+  case 3:                                                                      \
+  case 2:                                                                      \
+  case 1:                                                                      \
+    a += mux64(tail64_##ENDIANNES##_##ALIGNESS(v, len), prime_1);              \
+  /* fall through */                                                           \
+  case 0:                                                                      \
+    return final_weak_avalanche(a, b);                                         \
+  }
+
+uint64_t t1ha1_le(const void *data, size_t len, uint64_t seed) {
+  uint64_t a = seed;
+  uint64_t b = len;
+
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT
+  T1HA1_BODY(le, unaligned);
+#else
+  const bool misaligned = (((uintptr_t)data) & (ALIGNMENT_64 - 1)) != 0;
+  if (misaligned) {
+    T1HA1_BODY(le, unaligned);
+  } else {
+    T1HA1_BODY(le, aligned);
+  }
+#endif
+}
+
+uint64_t t1ha1_be(const void *data, size_t len, uint64_t seed) {
+  uint64_t a = seed;
+  uint64_t b = len;
+
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT
+  T1HA1_BODY(be, unaligned);
+#else
+  const bool misaligned = (((uintptr_t)data) & (ALIGNMENT_64 - 1)) != 0;
+  if (misaligned) {
+    T1HA1_BODY(be, unaligned);
+  } else {
+    T1HA1_BODY(be, aligned);
+  }
+#endif
+}
diff --git a/contrib/t1ha/t1ha2.c b/contrib/t1ha/t1ha2.c
new file mode 100644
index 0000000..4cb5281
--- /dev/null
+++ b/contrib/t1ha/t1ha2.c
@@ -0,0 +1,326 @@
+/*
+ *  Copyright (c) 2016-2018 Positive Technologies, https://www.ptsecurity.com,
+ *  Fast Positive Hash.
+ *
+ *  Portions Copyright (c) 2010-2018 Leonid Yuriev <leo@yuriev.ru>,
+ *  The 1Hippeus project (t1h).
+ *
+ *  This software is provided 'as-is', without any express or implied
+ *  warranty. In no event will the authors be held liable for any damages
+ *  arising from the use of this software.
+ *
+ *  Permission is granted to anyone to use this software for any purpose,
+ *  including commercial applications, and to alter it and redistribute it
+ *  freely, subject to the following restrictions:
+ *
+ *  1. The origin of this software must not be misrepresented; you must not
+ *     claim that you wrote the original software. If you use this software
+ *     in a product, an acknowledgement in the product documentation would be
+ *     appreciated but is not required.
+ *  2. Altered source versions must be plainly marked as such, and must not be
+ *     misrepresented as being the original software.
+ *  3. This notice may not be removed or altered from any source distribution.
+ */
+
+/*
+ * t1ha = { Fast Positive Hash, aka "Позитивный Хэш" }
+ * by [Positive Technologies](https://www.ptsecurity.ru)
+ *
+ * Briefly, it is a 64-bit Hash Function:
+ *  1. Created for 64-bit little-endian platforms, in predominantly for x86_64,
+ *     but portable and without penalties it can run on any 64-bit CPU.
+ *  2. In most cases up to 15% faster than City64, xxHash, mum-hash, metro-hash
+ *     and all others portable hash-functions (which do not use specific
+ *     hardware tricks).
+ *  3. Not suitable for cryptography.
+ *
+ * The Future will Positive. Всё будет хорошо.
+ *
+ * ACKNOWLEDGEMENT:
+ * The t1ha was originally developed by Leonid Yuriev (Леонид Юрьев)
+ * for The 1Hippeus project - zerocopy messaging in the spirit of Sparta!
+ */
+
+#include "config.h"
+#include "t1ha_bits.h"
+
+static __always_inline void init_ab(t1ha_state256_t *s, uint64_t x,
+                                    uint64_t y) {
+  s->n.a = x;
+  s->n.b = y;
+}
+
+static __always_inline void init_cd(t1ha_state256_t *s, uint64_t x,
+                                    uint64_t y) {
+  s->n.c = rot64(y, 23) + ~x;
+  s->n.d = ~y + rot64(x, 19);
+}
+
+/* TODO: C++ template in the next version */
+#define T1HA2_UPDATE(ENDIANNES, ALIGNESS, state, v)                            \
+  do {                                                                         \
+    t1ha_state256_t *const s = state;                                          \
+    const uint64_t w0 = fetch64_##ENDIANNES##_##ALIGNESS(v + 0);               \
+    const uint64_t w1 = fetch64_##ENDIANNES##_##ALIGNESS(v + 1);               \
+    const uint64_t w2 = fetch64_##ENDIANNES##_##ALIGNESS(v + 2);               \
+    const uint64_t w3 = fetch64_##ENDIANNES##_##ALIGNESS(v + 3);               \
+                                                                               \
+    const uint64_t d02 = w0 + rot64(w2 + s->n.d, 56);                          \
+    const uint64_t c13 = w1 + rot64(w3 + s->n.c, 19);                          \
+    s->n.c ^= s->n.a + rot64(w0, 57);                                          \
+    s->n.d ^= s->n.b + rot64(w1, 38);                                          \
+    s->n.b ^= prime_6 * (c13 + w2);                                            \
+    s->n.a ^= prime_5 * (d02 + w3);                                            \
+  } while (0)
+
+static __always_inline void squash(t1ha_state256_t *s) {
+  s->n.a ^= prime_6 * (s->n.c + rot64(s->n.d, 23));
+  s->n.b ^= prime_5 * (rot64(s->n.c, 19) + s->n.d);
+}
+
+/* TODO: C++ template in the next version */
+#define T1HA2_LOOP(ENDIANNES, ALIGNESS, state, data, len)                      \
+  do {                                                                         \
+    const void *detent = (const uint8_t *)data + len - 31;                     \
+    do {                                                                       \
+      const uint64_t *v = (const uint64_t *)data;                              \
+      data = (const uint64_t *)data + 4;                                       \
+      prefetch(data);                                                          \
+      T1HA2_UPDATE(le, ALIGNESS, state, v);                                    \
+    } while (likely(data < detent));                                           \
+  } while (0)
+
+/* TODO: C++ template in the next version */
+#define T1HA2_TAIL_AB(ENDIANNES, ALIGNESS, state, data, len)                   \
+  do {                                                                         \
+    t1ha_state256_t *const s = state;                                          \
+    const uint64_t *v = (const uint64_t *)data;                                \
+    switch (len) {                                                             \
+    default:                                                                   \
+      mixup64(&s->n.a, &s->n.b, fetch64_##ENDIANNES##_##ALIGNESS(v++),         \
+              prime_4);                                                        \
+    /* fall through */                                                         \
+    case 24:                                                                   \
+    case 23:                                                                   \
+    case 22:                                                                   \
+    case 21:                                                                   \
+    case 20:                                                                   \
+    case 19:                                                                   \
+    case 18:                                                                   \
+    case 17:                                                                   \
+      mixup64(&s->n.b, &s->n.a, fetch64_##ENDIANNES##_##ALIGNESS(v++),         \
+              prime_3);                                                        \
+    /* fall through */                                                         \
+    case 16:                                                                   \
+    case 15:                                                                   \
+    case 14:                                                                   \
+    case 13:                                                                   \
+    case 12:                                                                   \
+    case 11:                                                                   \
+    case 10:                                                                   \
+    case 9:                                                                    \
+      mixup64(&s->n.a, &s->n.b, fetch64_##ENDIANNES##_##ALIGNESS(v++),         \
+              prime_2);                                                        \
+    /* fall through */                                                         \
+    case 8:                                                                    \
+    case 7:                                                                    \
+    case 6:                                                                    \
+    case 5:                                                                    \
+    case 4:                                                                    \
+    case 3:                                                                    \
+    case 2:                                                                    \
+    case 1:                                                                    \
+      mixup64(&s->n.b, &s->n.a, tail64_##ENDIANNES##_##ALIGNESS(v, len),       \
+              prime_1);                                                        \
+    /* fall through */                                                         \
+    case 0:                                                                    \
+      return final64(s->n.a, s->n.b);                                          \
+    }                                                                          \
+  } while (0)
+
+/* TODO: C++ template in the next version */
+#define T1HA2_TAIL_ABCD(ENDIANNES, ALIGNESS, state, data, len)                 \
+  do {                                                                         \
+    t1ha_state256_t *const s = state;                                          \
+    const uint64_t *v = (const uint64_t *)data;                                \
+    switch (len) {                                                             \
+    default:                                                                   \
+      mixup64(&s->n.a, &s->n.d, fetch64_##ENDIANNES##_##ALIGNESS(v++),         \
+              prime_4);                                                        \
+    /* fall through */                                                         \
+    case 24:                                                                   \
+    case 23:                                                                   \
+    case 22:                                                                   \
+    case 21:                                                                   \
+    case 20:                                                                   \
+    case 19:                                                                   \
+    case 18:                                                                   \
+    case 17:                                                                   \
+      mixup64(&s->n.b, &s->n.a, fetch64_##ENDIANNES##_##ALIGNESS(v++),         \
+              prime_3);                                                        \
+    /* fall through */                                                         \
+    case 16:                                                                   \
+    case 15:                                                                   \
+    case 14:                                                                   \
+    case 13:                                                                   \
+    case 12:                                                                   \
+    case 11:                                                                   \
+    case 10:                                                                   \
+    case 9:                                                                    \
+      mixup64(&s->n.c, &s->n.b, fetch64_##ENDIANNES##_##ALIGNESS(v++),         \
+              prime_2);                                                        \
+    /* fall through */                                                         \
+    case 8:                                                                    \
+    case 7:                                                                    \
+    case 6:                                                                    \
+    case 5:                                                                    \
+    case 4:                                                                    \
+    case 3:                                                                    \
+    case 2:                                                                    \
+    case 1:                                                                    \
+      mixup64(&s->n.d, &s->n.c, tail64_##ENDIANNES##_##ALIGNESS(v, len),       \
+              prime_1);                                                        \
+    /* fall through */                                                         \
+    case 0:                                                                    \
+      return final128(s->n.a, s->n.b, s->n.c, s->n.d, extra_result);           \
+    }                                                                          \
+  } while (0)
+
+static __always_inline uint64_t final128(uint64_t a, uint64_t b, uint64_t c,
+                                         uint64_t d, uint64_t *h) {
+  mixup64(&a, &b, rot64(c, 41) ^ d, prime_0);
+  mixup64(&b, &c, rot64(d, 23) ^ a, prime_6);
+  mixup64(&c, &d, rot64(a, 19) ^ b, prime_5);
+  mixup64(&d, &a, rot64(b, 31) ^ c, prime_4);
+  *h = c + d;
+  return a ^ b;
+}
+
+//------------------------------------------------------------------------------
+
+uint64_t t1ha2_atonce(const void *data, size_t length, uint64_t seed) {
+  t1ha_state256_t state;
+  init_ab(&state, seed, length);
+
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT
+  if (unlikely(length > 32)) {
+    init_cd(&state, seed, length);
+    T1HA2_LOOP(le, unaligned, &state, data, length);
+    squash(&state);
+    length &= 31;
+  }
+  T1HA2_TAIL_AB(le, unaligned, &state, data, length);
+#else
+  const bool misaligned = (((uintptr_t)data) & (ALIGNMENT_64 - 1)) != 0;
+  if (misaligned) {
+    if (unlikely(length > 32)) {
+      init_cd(&state, seed, length);
+      T1HA2_LOOP(le, unaligned, &state, data, length);
+      squash(&state);
+      length &= 31;
+    }
+    T1HA2_TAIL_AB(le, unaligned, &state, data, length);
+  } else {
+    if (unlikely(length > 32)) {
+      init_cd(&state, seed, length);
+      T1HA2_LOOP(le, aligned, &state, data, length);
+      squash(&state);
+      length &= 31;
+    }
+    T1HA2_TAIL_AB(le, aligned, &state, data, length);
+  }
+#endif
+}
+
+uint64_t t1ha2_atonce128(uint64_t *__restrict extra_result,
+                         const void *__restrict data, size_t length,
+                         uint64_t seed) {
+  t1ha_state256_t state;
+  init_ab(&state, seed, length);
+  init_cd(&state, seed, length);
+
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT
+  if (unlikely(length > 32)) {
+    T1HA2_LOOP(le, unaligned, &state, data, length);
+    length &= 31;
+  }
+  T1HA2_TAIL_ABCD(le, unaligned, &state, data, length);
+#else
+  const bool misaligned = (((uintptr_t)data) & (ALIGNMENT_64 - 1)) != 0;
+  if (misaligned) {
+    if (unlikely(length > 32)) {
+      T1HA2_LOOP(le, unaligned, &state, data, length);
+      length &= 31;
+    }
+    T1HA2_TAIL_ABCD(le, unaligned, &state, data, length);
+  } else {
+    if (unlikely(length > 32)) {
+      T1HA2_LOOP(le, aligned, &state, data, length);
+      length &= 31;
+    }
+    T1HA2_TAIL_ABCD(le, aligned, &state, data, length);
+  }
+#endif
+}
+
+//------------------------------------------------------------------------------
+
+void t1ha2_init(t1ha_context_t *ctx, uint64_t seed_x, uint64_t seed_y) {
+  init_ab(&ctx->state, seed_x, seed_y);
+  init_cd(&ctx->state, seed_x, seed_y);
+  ctx->partial = 0;
+  ctx->total = 0;
+}
+
+void t1ha2_update(t1ha_context_t *__restrict ctx, const void *__restrict data,
+                  size_t length) {
+  ctx->total += length;
+
+  if (ctx->partial) {
+    const size_t left = 32 - ctx->partial;
+    const size_t chunk = (length >= left) ? left : length;
+    memcpy(ctx->buffer.bytes + ctx->partial, data, chunk);
+    ctx->partial += chunk;
+    if (ctx->partial < 32) {
+      assert(left >= length);
+      return;
+    }
+    ctx->partial = 0;
+    data = (const uint8_t *)data + chunk;
+    length -= chunk;
+    T1HA2_UPDATE(le, aligned, &ctx->state, ctx->buffer.u64);
+  }
+
+  if (length >= 32) {
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT
+    T1HA2_LOOP(le, unaligned, &ctx->state, data, length);
+#else
+    const bool misaligned = (((uintptr_t)data) & (ALIGNMENT_64 - 1)) != 0;
+    if (misaligned) {
+      T1HA2_LOOP(le, unaligned, &ctx->state, data, length);
+    } else {
+      T1HA2_LOOP(le, aligned, &ctx->state, data, length);
+    }
+#endif
+    length &= 31;
+  }
+
+  if (length)
+    memcpy(ctx->buffer.bytes, data, ctx->partial = length);
+}
+
+uint64_t t1ha2_final(t1ha_context_t *__restrict ctx,
+                     uint64_t *__restrict extra_result) {
+  uint64_t bits = (ctx->total << 3) ^ (UINT64_C(1) << 63);
+#if __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__
+  bits = bswap64(bits);
+#endif
+  t1ha2_update(ctx, &bits, 8);
+
+  if (likely(!extra_result)) {
+    squash(&ctx->state);
+    T1HA2_TAIL_AB(le, aligned, &ctx->state, ctx->buffer.u64, ctx->partial);
+  }
+
+  T1HA2_TAIL_ABCD(le, aligned, &ctx->state, ctx->buffer.u64, ctx->partial);
+}
diff --git a/contrib/t1ha/t1ha_bits.h b/contrib/t1ha/t1ha_bits.h
new file mode 100644
index 0000000..5710d2d
--- /dev/null
+++ b/contrib/t1ha/t1ha_bits.h
@@ -0,0 +1,1171 @@
+/*
+ *  Copyright (c) 2016-2018 Positive Technologies, https://www.ptsecurity.com,
+ *  Fast Positive Hash.
+ *
+ *  Portions Copyright (c) 2010-2018 Leonid Yuriev <leo@yuriev.ru>,
+ *  The 1Hippeus project (t1h).
+ *
+ *  This software is provided 'as-is', without any express or implied
+ *  warranty. In no event will the authors be held liable for any damages
+ *  arising from the use of this software.
+ *
+ *  Permission is granted to anyone to use this software for any purpose,
+ *  including commercial applications, and to alter it and redistribute it
+ *  freely, subject to the following restrictions:
+ *
+ *  1. The origin of this software must not be misrepresented; you must not
+ *     claim that you wrote the original software. If you use this software
+ *     in a product, an acknowledgement in the product documentation would be
+ *     appreciated but is not required.
+ *  2. Altered source versions must be plainly marked as such, and must not be
+ *     misrepresented as being the original software.
+ *  3. This notice may not be removed or altered from any source distribution.
+ */
+
+/*
+ * t1ha = { Fast Positive Hash, aka "Позитивный Хэш" }
+ * by [Positive Technologies](https://www.ptsecurity.ru)
+ *
+ * Briefly, it is a 64-bit Hash Function:
+ *  1. Created for 64-bit little-endian platforms, in predominantly for x86_64,
+ *     but portable and without penalties it can run on any 64-bit CPU.
+ *  2. In most cases up to 15% faster than City64, xxHash, mum-hash, metro-hash
+ *     and all others portable hash-functions (which do not use specific
+ *     hardware tricks).
+ *  3. Not suitable for cryptography.
+ *
+ * The Future will Positive. Всё будет хорошо.
+ *
+ * ACKNOWLEDGEMENT:
+ * The t1ha was originally developed by Leonid Yuriev (Леонид Юрьев)
+ * for The 1Hippeus project - zerocopy messaging in the spirit of Sparta!
+ */
+
+#pragma once
+
+#if defined(_MSC_VER)
+#pragma warning(disable : 4201) /* nameless struct/union */
+#if _MSC_VER > 1800
+#pragma warning(disable : 4464) /* relative include path contains '..' */
+#endif                          /* 1800 */
+#endif                          /* MSVC */
+
+#include "config.h"
+#include "t1ha.h"
+
+#ifndef T1HA_USE_FAST_ONESHOT_READ
+/* Define it to 1 for little bit faster code.
+ * Unfortunately this may triggering a false-positive alarms from Valgrind,
+ * AddressSanitizer and other similar tool.
+ * So, define it to 0 for calmness if doubt. */
+#define T1HA_USE_FAST_ONESHOT_READ 1
+#endif /* T1HA_USE_FAST_ONESHOT_READ */
+
+/*****************************************************************************/
+
+#include <assert.h>  /* for assert() */
+#include <stdbool.h> /* for bool */
+#include <string.h>  /* for memcpy() */
+
+#if __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__ &&                               \
+    __BYTE_ORDER__ != __ORDER_BIG_ENDIAN__
+#error Unsupported byte order.
+#endif
+
+#define T1HA_CONFIG_UNALIGNED_ACCESS__UNABLE 0
+#define T1HA_CONFIG_UNALIGNED_ACCESS__SLOW 1
+#define T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT 2
+
+#ifndef T1HA_CONFIG_UNALIGNED_ACCESS
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+#define T1HA_CONFIG_UNALIGNED_ACCESS T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT
+#elif defined(__ia32__)
+#define T1HA_CONFIG_UNALIGNED_ACCESS T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT
+#elif defined(__e2k__)
+#define T1HA_CONFIG_UNALIGNED_ACCESS T1HA_CONFIG_UNALIGNED_ACCESS__SLOW
+#elif defined(__ARM_FEATURE_UNALIGNED)
+#define T1HA_CONFIG_UNALIGNED_ACCESS T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT
+#else
+#define T1HA_CONFIG_UNALIGNED_ACCESS T1HA_CONFIG_UNALIGNED_ACCESS__UNABLE
+#endif
+#endif /* T1HA_CONFIG_UNALIGNED_ACCESS */
+
+#define ALIGNMENT_16 2
+#define ALIGNMENT_32 4
+#if UINTPTR_MAX > 0xffffFFFFul || ULONG_MAX > 0xffffFFFFul
+#define ALIGNMENT_64 8
+#else
+#define ALIGNMENT_64 4
+#endif
+
+#ifndef PAGESIZE
+#define PAGESIZE 4096
+#endif /* PAGESIZE */
+
+/***************************************************************************/
+
+#ifndef __has_builtin
+#define __has_builtin(x) (0)
+#endif
+
+#ifndef __has_warning
+#define __has_warning(x) (0)
+#endif
+
+#ifndef __has_feature
+#define __has_feature(x) (0)
+#endif
+
+#ifndef __has_extension
+#define __has_extension(x) (0)
+#endif
+
+#if __GNUC_PREREQ(4, 4) || defined(__clang__)
+
+#if defined(__ia32__) || defined(__e2k__)
+#include <x86intrin.h>
+#endif
+
+#if defined(__ia32__) && !defined(__cpuid_count)
+#include <cpuid.h>
+#endif
+
+#if defined(__e2k__)
+#include <e2kbuiltin.h>
+#endif
+
+#ifndef likely
+#define likely(cond) __builtin_expect(!!(cond), 1)
+#endif
+
+#ifndef unlikely
+#define unlikely(cond) __builtin_expect(!!(cond), 0)
+#endif
+
+#if __GNUC_PREREQ(4, 5) || __has_builtin(__builtin_unreachable)
+#define unreachable() __builtin_unreachable()
+#endif
+
+#define bswap64(v) __builtin_bswap64(v)
+#define bswap32(v) __builtin_bswap32(v)
+#if __GNUC_PREREQ(4, 8) || __has_builtin(__builtin_bswap16)
+#define bswap16(v) __builtin_bswap16(v)
+#endif
+
+#if !defined(__maybe_unused) && (__GNUC_PREREQ(4, 3) || __has_attribute(unused))
+#define __maybe_unused __attribute__((unused))
+#endif
+
+#if !defined(__always_inline) &&                                               \
+    (__GNUC_PREREQ(3, 2) || __has_attribute(always_inline))
+#define __always_inline __inline __attribute__((always_inline))
+#endif
+
+#if defined(__e2k__)
+
+#if __iset__ >= 3
+#define mul_64x64_high(a, b) __builtin_e2k_umulhd(a, b)
+#endif /* __iset__ >= 3 */
+
+#if __iset__ >= 5
+static __maybe_unused __always_inline unsigned
+e2k_add64carry_first(uint64_t base, uint64_t addend, uint64_t *sum) {
+  *sum = base + addend;
+  return (unsigned)__builtin_e2k_addcd_c(base, addend, 0);
+}
+#define add64carry_first(base, addend, sum)                                    \
+  e2k_add64carry_first(base, addend, sum)
+
+static __maybe_unused __always_inline unsigned
+e2k_add64carry_next(unsigned carry, uint64_t base, uint64_t addend,
+                    uint64_t *sum) {
+  *sum = __builtin_e2k_addcd(base, addend, carry);
+  return (unsigned)__builtin_e2k_addcd_c(base, addend, carry);
+}
+#define add64carry_next(carry, base, addend, sum)                              \
+  e2k_add64carry_next(carry, base, addend, sum)
+
+static __maybe_unused __always_inline void e2k_add64carry_last(unsigned carry,
+                                                               uint64_t base,
+                                                               uint64_t addend,
+                                                               uint64_t *sum) {
+  *sum = __builtin_e2k_addcd(base, addend, carry);
+}
+#define add64carry_last(carry, base, addend, sum)                              \
+  e2k_add64carry_last(carry, base, addend, sum)
+#endif /* __iset__ >= 5 */
+
+#define fetch64_be_aligned(ptr) ((uint64_t)__builtin_e2k_ld_64s_be(ptr))
+#define fetch32_be_aligned(ptr) ((uint32_t)__builtin_e2k_ld_32u_be(ptr))
+
+#endif /* __e2k__ Elbrus */
+
+#elif defined(_MSC_VER)
+
+#if _MSC_FULL_VER < 190024218 && defined(_M_IX86)
+#pragma message(                                                               \
+    "For AES-NI at least \"Microsoft C/C++ Compiler\" version 19.00.24218 (Visual Studio 2015 Update 5) is required.")
+#endif
+#if _MSC_FULL_VER < 191025019
+#pragma message(                                                               \
+    "It is recommended to use \"Microsoft C/C++ Compiler\" version 19.10.25019 (Visual Studio 2017) or newer.")
+#endif
+#if _MSC_FULL_VER < 180040629
+#error At least "Microsoft C/C++ Compiler" version 18.00.40629 (Visual Studio 2013 Update 5) is required.
+#endif
+
+#pragma warning(push, 1)
+
+#include <intrin.h>
+#include <stdlib.h>
+#define likely(cond) (cond)
+#define unlikely(cond) (cond)
+#define unreachable() __assume(0)
+#define bswap64(v) _byteswap_uint64(v)
+#define bswap32(v) _byteswap_ulong(v)
+#define bswap16(v) _byteswap_ushort(v)
+#define rot64(v, s) _rotr64(v, s)
+#define rot32(v, s) _rotr(v, s)
+#define __always_inline __forceinline
+
+#if defined(_M_X64) || defined(_M_IA64)
+#pragma intrinsic(_umul128)
+#define mul_64x64_128(a, b, ph) _umul128(a, b, ph)
+#pragma intrinsic(_addcarry_u64)
+#define add64carry_first(base, addend, sum) _addcarry_u64(0, base, addend, sum)
+#define add64carry_next(carry, base, addend, sum)                              \
+  _addcarry_u64(carry, base, addend, sum)
+#define add64carry_last(carry, base, addend, sum)                              \
+  (void)_addcarry_u64(carry, base, addend, sum)
+#endif
+
+#if defined(_M_ARM64) || defined(_M_X64) || defined(_M_IA64)
+#pragma intrinsic(__umulh)
+#define mul_64x64_high(a, b) __umulh(a, b)
+#endif
+
+#if defined(_M_IX86)
+#pragma intrinsic(__emulu)
+#define mul_32x32_64(a, b) __emulu(a, b)
+
+#if _MSC_FULL_VER >= 190024231 /* LY: workaround for optimizer bug */
+#pragma intrinsic(_addcarry_u32)
+#define add32carry_first(base, addend, sum) _addcarry_u32(0, base, addend, sum)
+#define add32carry_next(carry, base, addend, sum)                              \
+  _addcarry_u32(carry, base, addend, sum)
+#define add32carry_last(carry, base, addend, sum)                              \
+  (void)_addcarry_u32(carry, base, addend, sum)
+
+static __forceinline char
+msvc32_add64carry_first(uint64_t base, uint64_t addend, uint64_t *sum) {
+  uint32_t *const sum32 = (uint32_t *)sum;
+  const uint32_t base_32l = (uint32_t)base;
+  const uint32_t base_32h = (uint32_t)(base >> 32);
+  const uint32_t addend_32l = (uint32_t)addend;
+  const uint32_t addend_32h = (uint32_t)(addend >> 32);
+  return add32carry_next(add32carry_first(base_32l, addend_32l, sum32),
+                         base_32h, addend_32h, sum32 + 1);
+}
+#define add64carry_first(base, addend, sum)                                    \
+  msvc32_add64carry_first(base, addend, sum)
+
+static __forceinline char msvc32_add64carry_next(char carry, uint64_t base,
+                                                 uint64_t addend,
+                                                 uint64_t *sum) {
+  uint32_t *const sum32 = (uint32_t *)sum;
+  const uint32_t base_32l = (uint32_t)base;
+  const uint32_t base_32h = (uint32_t)(base >> 32);
+  const uint32_t addend_32l = (uint32_t)addend;
+  const uint32_t addend_32h = (uint32_t)(addend >> 32);
+  return add32carry_next(add32carry_next(carry, base_32l, addend_32l, sum32),
+                         base_32h, addend_32h, sum32 + 1);
+}
+#define add64carry_next(carry, base, addend, sum)                              \
+  msvc32_add64carry_next(carry, base, addend, sum)
+
+static __forceinline void msvc32_add64carry_last(char carry, uint64_t base,
+                                                 uint64_t addend,
+                                                 uint64_t *sum) {
+  uint32_t *const sum32 = (uint32_t *)sum;
+  const uint32_t base_32l = (uint32_t)base;
+  const uint32_t base_32h = (uint32_t)(base >> 32);
+  const uint32_t addend_32l = (uint32_t)addend;
+  const uint32_t addend_32h = (uint32_t)(addend >> 32);
+  add32carry_last(add32carry_next(carry, base_32l, addend_32l, sum32), base_32h,
+                  addend_32h, sum32 + 1);
+}
+#define add64carry_last(carry, base, addend, sum)                              \
+  msvc32_add64carry_last(carry, base, addend, sum)
+#endif /* _MSC_FULL_VER >= 190024231 */
+
+#elif defined(_M_ARM)
+#define mul_32x32_64(a, b) _arm_umull(a, b)
+#endif
+
+#pragma warning(pop)
+#pragma warning(disable : 4514) /* 'xyz': unreferenced inline function         \
+                                   has been removed */
+#pragma warning(disable : 4710) /* 'xyz': function not inlined */
+#pragma warning(disable : 4711) /* function 'xyz' selected for                 \
+                                   automatic inline expansion */
+#pragma warning(disable : 4127) /* conditional expression is constant */
+#pragma warning(disable : 4702) /* unreachable code */
+#endif                          /* Compiler */
+
+#ifndef likely
+#define likely(cond) (cond)
+#endif
+#ifndef unlikely
+#define unlikely(cond) (cond)
+#endif
+#ifndef __maybe_unused
+#define __maybe_unused
+#endif
+#ifndef __always_inline
+#define __always_inline __inline
+#endif
+#ifndef unreachable
+#define unreachable()                                                          \
+  do {                                                                         \
+  } while (1)
+#endif
+
+#ifndef bswap64
+#if defined(bswap_64)
+#define bswap64 bswap_64
+#elif defined(__bswap_64)
+#define bswap64 __bswap_64
+#else
+static __always_inline uint64_t bswap64(uint64_t v) {
+  return v << 56 | v >> 56 | ((v << 40) & UINT64_C(0x00ff000000000000)) |
+         ((v << 24) & UINT64_C(0x0000ff0000000000)) |
+         ((v << 8) & UINT64_C(0x000000ff00000000)) |
+         ((v >> 8) & UINT64_C(0x00000000ff000000)) |
+         ((v >> 24) & UINT64_C(0x0000000000ff0000)) |
+         ((v >> 40) & UINT64_C(0x000000000000ff00));
+}
+#endif
+#endif /* bswap64 */
+
+#ifndef bswap32
+#if defined(bswap_32)
+#define bswap32 bswap_32
+#elif defined(__bswap_32)
+#define bswap32 __bswap_32
+#else
+static __always_inline uint32_t bswap32(uint32_t v) {
+  return v << 24 | v >> 24 | ((v << 8) & UINT32_C(0x00ff0000)) |
+         ((v >> 8) & UINT32_C(0x0000ff00));
+}
+#endif
+#endif /* bswap32 */
+
+#ifndef bswap16
+#if defined(bswap_16)
+#define bswap16 bswap_16
+#elif defined(__bswap_16)
+#define bswap16 __bswap_16
+#else
+static __always_inline uint16_t bswap16(uint16_t v) { return v << 8 | v >> 8; }
+#endif
+#endif /* bswap16 */
+
+#ifndef read_unaligned
+#if defined(__GNUC__) || __has_attribute(packed)
+typedef struct {
+  uint8_t unaligned_8;
+  uint16_t unaligned_16;
+  uint32_t unaligned_32;
+  uint64_t unaligned_64;
+} __attribute__((packed)) t1ha_unaligned_proxy;
+#define read_unaligned(ptr, bits)                                              \
+  (((const t1ha_unaligned_proxy *)((const uint8_t *)(ptr)-offsetof(            \
+        t1ha_unaligned_proxy, unaligned_##bits)))                              \
+       ->unaligned_##bits)
+#elif defined(_MSC_VER)
+#pragma warning(                                                               \
+    disable : 4235) /* nonstandard extension used: '__unaligned'               \
+                     * keyword not supported on this architecture */
+#define read_unaligned(ptr, bits) (*(const __unaligned uint##bits##_t *)(ptr))
+#else
+#pragma pack(push, 1)
+typedef struct {
+  uint8_t unaligned_8;
+  uint16_t unaligned_16;
+  uint32_t unaligned_32;
+  uint64_t unaligned_64;
+} t1ha_unaligned_proxy;
+#pragma pack(pop)
+#define read_unaligned(ptr, bits)                                              \
+  (((const t1ha_unaligned_proxy *)((const uint8_t *)(ptr)-offsetof(            \
+        t1ha_unaligned_proxy, unaligned_##bits)))                              \
+       ->unaligned_##bits)
+#endif
+#endif /* read_unaligned */
+
+#ifndef read_aligned
+#if __GNUC_PREREQ(4, 8) || __has_builtin(__builtin_assume_aligned)
+#define read_aligned(ptr, bits)                                                \
+  (*(const uint##bits##_t *)__builtin_assume_aligned(ptr, ALIGNMENT_##bits))
+#elif (__GNUC_PREREQ(3, 3) || __has_attribute(aligned)) && !defined(__clang__)
+#define read_aligned(ptr, bits)                                                \
+  (*(const uint##bits##_t __attribute__((aligned(ALIGNMENT_##bits))) *)(ptr))
+#elif __has_attribute(assume_aligned)
+
+static __always_inline const
+    uint16_t *__attribute__((assume_aligned(ALIGNMENT_16)))
+    cast_aligned_16(const void *ptr) {
+  return (const uint16_t *)ptr;
+}
+static __always_inline const
+    uint32_t *__attribute__((assume_aligned(ALIGNMENT_32)))
+    cast_aligned_32(const void *ptr) {
+  return (const uint32_t *)ptr;
+}
+static __always_inline const
+    uint64_t *__attribute__((assume_aligned(ALIGNMENT_64)))
+    cast_aligned_64(const void *ptr) {
+  return (const uint64_t *)ptr;
+}
+
+#define read_aligned(ptr, bits) (*cast_aligned_##bits(ptr))
+
+#elif defined(_MSC_VER)
+#define read_aligned(ptr, bits)                                                \
+  (*(const __declspec(align(ALIGNMENT_##bits)) uint##bits##_t *)(ptr))
+#else
+#define read_aligned(ptr, bits) (*(const uint##bits##_t *)(ptr))
+#endif
+#endif /* read_aligned */
+
+#ifndef prefetch
+#if (__GNUC_PREREQ(4, 0) || __has_builtin(__builtin_prefetch)) &&              \
+    !defined(__ia32__)
+#define prefetch(ptr) __builtin_prefetch(ptr)
+#elif defined(_M_ARM64) || defined(_M_ARM)
+#define prefetch(ptr) __prefetch(ptr)
+#else
+#define prefetch(ptr)                                                          \
+  do {                                                                         \
+    (void)(ptr);                                                               \
+  } while (0)
+#endif
+#endif /* prefetch */
+
+#if __has_warning("-Wconstant-logical-operand")
+#if defined(__clang__)
+#pragma clang diagnostic ignored "-Wconstant-logical-operand"
+#elif defined(__GNUC__)
+#pragma GCC diagnostic ignored "-Wconstant-logical-operand"
+#else
+#pragma warning disable "constant-logical-operand"
+#endif
+#endif /* -Wconstant-logical-operand */
+
+#if __has_warning("-Wtautological-pointer-compare")
+#if defined(__clang__)
+#pragma clang diagnostic ignored "-Wtautological-pointer-compare"
+#elif defined(__GNUC__)
+#pragma GCC diagnostic ignored "-Wtautological-pointer-compare"
+#else
+#pragma warning disable "tautological-pointer-compare"
+#endif
+#endif /* -Wtautological-pointer-compare */
+
+/***************************************************************************/
+
+/*---------------------------------------------------------- Little Endian */
+
+#ifndef fetch16_le_aligned
+static __always_inline uint16_t fetch16_le_aligned(const void *v) {
+  assert(((uintptr_t)v) % ALIGNMENT_16 == 0);
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  return read_aligned(v, 16);
+#else
+  return bswap16(read_aligned(v, 16));
+#endif
+}
+#endif /* fetch16_le_aligned */
+
+#ifndef fetch16_le_unaligned
+static __always_inline uint16_t fetch16_le_unaligned(const void *v) {
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__UNABLE
+  const uint8_t *p = (const uint8_t *)v;
+  return p[0] | (uint16_t)p[1] << 8;
+#elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  return read_unaligned(v, 16);
+#else
+  return bswap16(read_unaligned(v, 16));
+#endif
+}
+#endif /* fetch16_le_unaligned */
+
+#ifndef fetch32_le_aligned
+static __always_inline uint32_t fetch32_le_aligned(const void *v) {
+  assert(((uintptr_t)v) % ALIGNMENT_32 == 0);
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  return read_aligned(v, 32);
+#else
+  return bswap32(read_aligned(v, 32));
+#endif
+}
+#endif /* fetch32_le_aligned */
+
+#ifndef fetch32_le_unaligned
+static __always_inline uint32_t fetch32_le_unaligned(const void *v) {
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__UNABLE
+  return fetch16_le_unaligned(v) |
+         (uint32_t)fetch16_le_unaligned((const uint8_t *)v + 2) << 16;
+#elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  return read_unaligned(v, 32);
+#else
+  return bswap32(read_unaligned(v, 32));
+#endif
+}
+#endif /* fetch32_le_unaligned */
+
+#ifndef fetch64_le_aligned
+static __always_inline uint64_t fetch64_le_aligned(const void *v) {
+  assert(((uintptr_t)v) % ALIGNMENT_64 == 0);
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  return read_aligned(v, 64);
+#else
+  return bswap64(read_aligned(v, 64));
+#endif
+}
+#endif /* fetch64_le_aligned */
+
+#ifndef fetch64_le_unaligned
+static __always_inline uint64_t fetch64_le_unaligned(const void *v) {
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__UNABLE
+  return fetch32_le_unaligned(v) |
+         (uint64_t)fetch32_le_unaligned((const uint8_t *)v + 4) << 32;
+#elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  return read_unaligned(v, 64);
+#else
+  return bswap64(read_unaligned(v, 64));
+#endif
+}
+#endif /* fetch64_le_unaligned */
+
+static __always_inline uint64_t tail64_le_aligned(const void *v, size_t tail) {
+  const uint8_t *const p = (const uint8_t *)v;
+#if T1HA_USE_FAST_ONESHOT_READ && !defined(__SANITIZE_ADDRESS__)
+  /* We can perform a 'oneshot' read, which is little bit faster. */
+  const unsigned shift = ((8 - tail) & 7) << 3;
+  return fetch64_le_aligned(p) & ((~UINT64_C(0)) >> shift);
+#else
+  uint64_t r = 0;
+  switch (tail & 7) {
+  default:
+    unreachable();
+/* fall through */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  /* For most CPUs this code is better when not needed byte reordering. */
+  case 0:
+    return fetch64_le_aligned(p);
+  case 7:
+    r = (uint64_t)p[6] << 8;
+  /* fall through */
+  case 6:
+    r += p[5];
+    r <<= 8;
+  /* fall through */
+  case 5:
+    r += p[4];
+    r <<= 32;
+  /* fall through */
+  case 4:
+    return r + fetch32_le_aligned(p);
+  case 3:
+    r = (uint64_t)p[2] << 16;
+  /* fall through */
+  case 2:
+    return r + fetch16_le_aligned(p);
+  case 1:
+    return p[0];
+#else
+  case 0:
+    r = p[7] << 8;
+  /* fall through */
+  case 7:
+    r += p[6];
+    r <<= 8;
+  /* fall through */
+  case 6:
+    r += p[5];
+    r <<= 8;
+  /* fall through */
+  case 5:
+    r += p[4];
+    r <<= 8;
+  /* fall through */
+  case 4:
+    r += p[3];
+    r <<= 8;
+  /* fall through */
+  case 3:
+    r += p[2];
+    r <<= 8;
+  /* fall through */
+  case 2:
+    r += p[1];
+    r <<= 8;
+  /* fall through */
+  case 1:
+    return r + p[0];
+#endif
+  }
+#endif /* T1HA_USE_FAST_ONESHOT_READ */
+}
+
+#if T1HA_USE_FAST_ONESHOT_READ &&                                              \
+    T1HA_CONFIG_UNALIGNED_ACCESS != T1HA_CONFIG_UNALIGNED_ACCESS__UNABLE &&    \
+    defined(PAGESIZE) && !defined(__sun) && !defined(__SANITIZE_ADDRESS__)
+#define can_read_underside(ptr, size)                                          \
+  ((size) <= sizeof(uintptr_t) && ((PAGESIZE - (size)) & (uintptr_t)(ptr)) != 0)
+#endif /* T1HA_USE_FAST_ONESHOT_READ */
+
+static __always_inline uint64_t tail64_le_unaligned(const void *v,
+                                                    size_t tail) {
+  const uint8_t *p = (const uint8_t *)v;
+#ifdef can_read_underside
+  /* On some systems (e.g. x86) we can perform a 'oneshot' read, which
+   * is little bit faster. Thanks Marcin Żukowski <marcin.zukowski@gmail.com>
+   * for the reminder. */
+  const unsigned offset = (8 - tail) & 7;
+  const unsigned shift = offset << 3;
+  if (likely(can_read_underside(p, 8))) {
+    p -= offset;
+    return fetch64_le_unaligned(p) >> shift;
+  }
+  return fetch64_le_unaligned(p) & ((~UINT64_C(0)) >> shift);
+#else
+  uint64_t r = 0;
+  switch (tail & 7) {
+  default:
+    unreachable();
+/* fall through */
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT && \
+    __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  /* For most CPUs this code is better when not needed
+   * copying for alignment or byte reordering. */
+  case 0:
+    return fetch64_le_unaligned(p);
+  case 7:
+    r = (uint64_t)p[6] << 8;
+  /* fall through */
+  case 6:
+    r += p[5];
+    r <<= 8;
+  /* fall through */
+  case 5:
+    r += p[4];
+    r <<= 32;
+  /* fall through */
+  case 4:
+    return r + fetch32_le_unaligned(p);
+  case 3:
+    r = (uint64_t)p[2] << 16;
+  /* fall through */
+  case 2:
+    return r + fetch16_le_unaligned(p);
+  case 1:
+    return p[0];
+#else
+  /* For most CPUs this code is better than a
+   * copying for alignment and/or byte reordering. */
+  case 0:
+    r = p[7] << 8;
+  /* fall through */
+  case 7:
+    r += p[6];
+    r <<= 8;
+  /* fall through */
+  case 6:
+    r += p[5];
+    r <<= 8;
+  /* fall through */
+  case 5:
+    r += p[4];
+    r <<= 8;
+  /* fall through */
+  case 4:
+    r += p[3];
+    r <<= 8;
+  /* fall through */
+  case 3:
+    r += p[2];
+    r <<= 8;
+  /* fall through */
+  case 2:
+    r += p[1];
+    r <<= 8;
+  /* fall through */
+  case 1:
+    return r + p[0];
+#endif
+  }
+#endif /* can_read_underside */
+}
+
+/*------------------------------------------------------------- Big Endian */
+
+#ifndef fetch16_be_aligned
+static __maybe_unused __always_inline uint16_t
+fetch16_be_aligned(const void *v) {
+  assert(((uintptr_t)v) % ALIGNMENT_16 == 0);
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  return read_aligned(v, 16);
+#else
+  return bswap16(read_aligned(v, 16));
+#endif
+}
+#endif /* fetch16_be_aligned */
+
+#ifndef fetch16_be_unaligned
+static __maybe_unused __always_inline uint16_t
+fetch16_be_unaligned(const void *v) {
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__UNABLE
+  const uint8_t *p = (const uint8_t *)v;
+  return (uint16_t)p[0] << 8 | p[1];
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  return read_unaligned(v, 16);
+#else
+  return bswap16(read_unaligned(v, 16));
+#endif
+}
+#endif /* fetch16_be_unaligned */
+
+#ifndef fetch32_be_aligned
+static __maybe_unused __always_inline uint32_t
+fetch32_be_aligned(const void *v) {
+  assert(((uintptr_t)v) % ALIGNMENT_32 == 0);
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  return read_aligned(v, 32);
+#else
+  return bswap32(read_aligned(v, 32));
+#endif
+}
+#endif /* fetch32_be_aligned */
+
+#ifndef fetch32_be_unaligned
+static __maybe_unused __always_inline uint32_t
+fetch32_be_unaligned(const void *v) {
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__UNABLE
+  return (uint32_t)fetch16_be_unaligned(v) << 16 |
+         fetch16_be_unaligned((const uint8_t *)v + 2);
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  return read_unaligned(v, 32);
+#else
+  return bswap32(read_unaligned(v, 32));
+#endif
+}
+#endif /* fetch32_be_unaligned */
+
+#ifndef fetch64_be_aligned
+static __maybe_unused __always_inline uint64_t
+fetch64_be_aligned(const void *v) {
+  assert(((uintptr_t)v) % ALIGNMENT_64 == 0);
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  return read_aligned(v, 64);
+#else
+  return bswap64(read_aligned(v, 64));
+#endif
+}
+#endif /* fetch64_be_aligned */
+
+#ifndef fetch64_be_unaligned
+static __maybe_unused __always_inline uint64_t
+fetch64_be_unaligned(const void *v) {
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__UNABLE
+  return (uint64_t)fetch32_be_unaligned(v) << 32 |
+         fetch32_be_unaligned((const uint8_t *)v + 4);
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  return read_unaligned(v, 64);
+#else
+  return bswap64(read_unaligned(v, 64));
+#endif
+}
+#endif /* fetch64_be_unaligned */
+
+static __maybe_unused __always_inline uint64_t tail64_be_aligned(const void *v,
+                                                                 size_t tail) {
+  const uint8_t *const p = (const uint8_t *)v;
+#if T1HA_USE_FAST_ONESHOT_READ && !defined(__SANITIZE_ADDRESS__)
+  /* We can perform a 'oneshot' read, which is little bit faster. */
+  const unsigned shift = ((8 - tail) & 7) << 3;
+  return fetch64_be_aligned(p) >> shift;
+#else
+  switch (tail & 7) {
+  default:
+    unreachable();
+/* fall through */
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  /* For most CPUs this code is better when not byte reordering. */
+  case 1:
+    return p[0];
+  case 2:
+    return fetch16_be_aligned(p);
+  case 3:
+    return (uint32_t)fetch16_be_aligned(p) << 8 | p[2];
+  case 4:
+    return fetch32_be_aligned(p);
+  case 5:
+    return (uint64_t)fetch32_be_aligned(p) << 8 | p[4];
+  case 6:
+    return (uint64_t)fetch32_be_aligned(p) << 16 | fetch16_be_aligned(p + 4);
+  case 7:
+    return (uint64_t)fetch32_be_aligned(p) << 24 |
+           (uint32_t)fetch16_be_aligned(p + 4) << 8 | p[6];
+  case 0:
+    return fetch64_be_aligned(p);
+#else
+  case 1:
+    return p[0];
+  case 2:
+    return p[1] | (uint32_t)p[0] << 8;
+  case 3:
+    return p[2] | (uint32_t)p[1] << 8 | (uint32_t)p[0] << 16;
+  case 4:
+    return p[3] | (uint32_t)p[2] << 8 | (uint32_t)p[1] << 16 |
+           (uint32_t)p[0] << 24;
+  case 5:
+    return p[4] | (uint32_t)p[3] << 8 | (uint32_t)p[2] << 16 |
+           (uint32_t)p[1] << 24 | (uint64_t)p[0] << 32;
+  case 6:
+    return p[5] | (uint32_t)p[4] << 8 | (uint32_t)p[3] << 16 |
+           (uint32_t)p[2] << 24 | (uint64_t)p[1] << 32 | (uint64_t)p[0] << 40;
+  case 7:
+    return p[6] | (uint32_t)p[5] << 8 | (uint32_t)p[4] << 16 |
+           (uint32_t)p[3] << 24 | (uint64_t)p[2] << 32 | (uint64_t)p[1] << 40 |
+           (uint64_t)p[0] << 48;
+  case 0:
+    return p[7] | (uint32_t)p[6] << 8 | (uint32_t)p[5] << 16 |
+           (uint32_t)p[4] << 24 | (uint64_t)p[3] << 32 | (uint64_t)p[2] << 40 |
+           (uint64_t)p[1] << 48 | (uint64_t)p[0] << 56;
+#endif
+  }
+#endif /* T1HA_USE_FAST_ONESHOT_READ */
+}
+
+static __maybe_unused __always_inline uint64_t
+tail64_be_unaligned(const void *v, size_t tail) {
+  const uint8_t *p = (const uint8_t *)v;
+#ifdef can_read_underside
+  /* On some systems we can perform a 'oneshot' read, which is little bit
+   * faster. Thanks Marcin Żukowski <marcin.zukowski@gmail.com> for the
+   * reminder. */
+  const unsigned offset = (8 - tail) & 7;
+  const unsigned shift = offset << 3;
+  if (likely(can_read_underside(p, 8))) {
+    p -= offset;
+    return fetch64_be_unaligned(p) & ((~UINT64_C(0)) >> shift);
+  }
+  return fetch64_be_unaligned(p) >> shift;
+#else
+  switch (tail & 7) {
+  default:
+    unreachable();
+/* fall through */
+#if T1HA_CONFIG_UNALIGNED_ACCESS == T1HA_CONFIG_UNALIGNED_ACCESS__EFFICIENT && \
+    __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  /* For most CPUs this code is better when not needed
+   * copying for alignment or byte reordering. */
+  case 1:
+    return p[0];
+  case 2:
+    return fetch16_be_unaligned(p);
+  case 3:
+    return (uint32_t)fetch16_be_unaligned(p) << 8 | p[2];
+  case 4:
+    return fetch32_be(p);
+  case 5:
+    return (uint64_t)fetch32_be_unaligned(p) << 8 | p[4];
+  case 6:
+    return (uint64_t)fetch32_be_unaligned(p) << 16 |
+           fetch16_be_unaligned(p + 4);
+  case 7:
+    return (uint64_t)fetch32_be_unaligned(p) << 24 |
+           (uint32_t)fetch16_be_unaligned(p + 4) << 8 | p[6];
+  case 0:
+    return fetch64_be_unaligned(p);
+#else
+  /* For most CPUs this code is better than a
+   * copying for alignment and/or byte reordering. */
+  case 1:
+    return p[0];
+  case 2:
+    return p[1] | (uint32_t)p[0] << 8;
+  case 3:
+    return p[2] | (uint32_t)p[1] << 8 | (uint32_t)p[0] << 16;
+  case 4:
+    return p[3] | (uint32_t)p[2] << 8 | (uint32_t)p[1] << 16 |
+           (uint32_t)p[0] << 24;
+  case 5:
+    return p[4] | (uint32_t)p[3] << 8 | (uint32_t)p[2] << 16 |
+           (uint32_t)p[1] << 24 | (uint64_t)p[0] << 32;
+  case 6:
+    return p[5] | (uint32_t)p[4] << 8 | (uint32_t)p[3] << 16 |
+           (uint32_t)p[2] << 24 | (uint64_t)p[1] << 32 | (uint64_t)p[0] << 40;
+  case 7:
+    return p[6] | (uint32_t)p[5] << 8 | (uint32_t)p[4] << 16 |
+           (uint32_t)p[3] << 24 | (uint64_t)p[2] << 32 | (uint64_t)p[1] << 40 |
+           (uint64_t)p[0] << 48;
+  case 0:
+    return p[7] | (uint32_t)p[6] << 8 | (uint32_t)p[5] << 16 |
+           (uint32_t)p[4] << 24 | (uint64_t)p[3] << 32 | (uint64_t)p[2] << 40 |
+           (uint64_t)p[1] << 48 | (uint64_t)p[0] << 56;
+#endif
+  }
+#endif /* can_read_underside */
+}
+
+/***************************************************************************/
+
+#ifndef rot64
+static __always_inline uint64_t rot64(uint64_t v, unsigned s) {
+  return (v >> s) | (v << (64 - s));
+}
+#endif /* rot64 */
+
+#ifndef mul_32x32_64
+static __always_inline uint64_t mul_32x32_64(uint32_t a, uint32_t b) {
+  return a * (uint64_t)b;
+}
+#endif /* mul_32x32_64 */
+
+#ifndef add64carry_first
+static __maybe_unused __always_inline unsigned
+add64carry_first(uint64_t base, uint64_t addend, uint64_t *sum) {
+#if __has_builtin(__builtin_addcll)
+  unsigned long long carryout;
+  *sum = __builtin_addcll(base, addend, 0, &carryout);
+  return (unsigned)carryout;
+#else
+  *sum = base + addend;
+  return *sum < addend;
+#endif /* __has_builtin(__builtin_addcll) */
+}
+#endif /* add64carry_fist */
+
+#ifndef add64carry_next
+static __maybe_unused __always_inline unsigned
+add64carry_next(unsigned carry, uint64_t base, uint64_t addend, uint64_t *sum) {
+#if __has_builtin(__builtin_addcll)
+  unsigned long long carryout;
+  *sum = __builtin_addcll(base, addend, carry, &carryout);
+  return (unsigned)carryout;
+#else
+  *sum = base + addend + carry;
+  return *sum < addend || (carry && *sum == addend);
+#endif /* __has_builtin(__builtin_addcll) */
+}
+#endif /* add64carry_next */
+
+#ifndef add64carry_last
+static __maybe_unused __always_inline void
+add64carry_last(unsigned carry, uint64_t base, uint64_t addend, uint64_t *sum) {
+#if __has_builtin(__builtin_addcll)
+  unsigned long long carryout;
+  *sum = __builtin_addcll(base, addend, carry, &carryout);
+  (void)carryout;
+#else
+  *sum = base + addend + carry;
+#endif /* __has_builtin(__builtin_addcll) */
+}
+#endif /* add64carry_last */
+
+#ifndef mul_64x64_128
+static __maybe_unused __always_inline uint64_t mul_64x64_128(uint64_t a,
+                                                             uint64_t b,
+                                                             uint64_t *h) {
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  __uint128_t r = (__uint128_t)a * (__uint128_t)b;
+  /* modern GCC could nicely optimize this */
+  *h = (uint64_t)(r >> 64);
+  return (uint64_t)r;
+#elif defined(mul_64x64_high)
+  *h = mul_64x64_high(a, b);
+  return a * b;
+#else
+  /* performs 64x64 to 128 bit multiplication */
+  const uint64_t ll = mul_32x32_64((uint32_t)a, (uint32_t)b);
+  const uint64_t lh = mul_32x32_64(a >> 32, (uint32_t)b);
+  const uint64_t hl = mul_32x32_64((uint32_t)a, b >> 32);
+  const uint64_t hh = mul_32x32_64(a >> 32, b >> 32);
+
+  /* Few simplification are possible here for 32-bit architectures,
+   * but thus we would lost compatibility with the original 64-bit
+   * version.  Think is very bad idea, because then 32-bit t1ha will
+   * still (relatively) very slowly and well yet not compatible. */
+  uint64_t l;
+  add64carry_last(add64carry_first(ll, lh << 32, &l), hh, lh >> 32, h);
+  add64carry_last(add64carry_first(l, hl << 32, &l), *h, hl >> 32, h);
+  return l;
+#endif
+}
+#endif /* mul_64x64_128() */
+
+#ifndef mul_64x64_high
+static __maybe_unused __always_inline uint64_t mul_64x64_high(uint64_t a,
+                                                              uint64_t b) {
+  uint64_t h;
+  mul_64x64_128(a, b, &h);
+  return h;
+}
+#endif /* mul_64x64_high */
+
+/***************************************************************************/
+
+/* 'magic' primes */
+static const uint64_t prime_0 = UINT64_C(0xEC99BF0D8372CAAB);
+static const uint64_t prime_1 = UINT64_C(0x82434FE90EDCEF39);
+static const uint64_t prime_2 = UINT64_C(0xD4F06DB99D67BE4B);
+static const uint64_t prime_3 = UINT64_C(0xBD9CACC22C6E9571);
+static const uint64_t prime_4 = UINT64_C(0x9C06FAF4D023E3AB);
+static const uint64_t prime_5 = UINT64_C(0xC060724A8424F345);
+static const uint64_t prime_6 = UINT64_C(0xCB5AF53AE3AAAC31);
+
+/* xor high and low parts of full 128-bit product */
+static __maybe_unused __always_inline uint64_t mux64(uint64_t v,
+                                                     uint64_t prime) {
+  uint64_t l, h;
+  l = mul_64x64_128(v, prime, &h);
+  return l ^ h;
+}
+
+static __always_inline uint64_t final64(uint64_t a, uint64_t b) {
+  uint64_t x = (a + rot64(b, 41)) * prime_0;
+  uint64_t y = (rot64(a, 23) + b) * prime_6;
+  return mux64(x ^ y, prime_5);
+}
+
+static __always_inline void mixup64(uint64_t *__restrict a,
+                                    uint64_t *__restrict b, uint64_t v,
+                                    uint64_t prime) {
+  uint64_t h;
+  *a ^= mul_64x64_128(*b + v, prime, &h);
+  *b += h;
+}
+
+/***************************************************************************/
+
+typedef union t1ha_uint128 {
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  __uint128_t v;
+#endif
+  struct {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+    uint64_t l;
+    uint64_t h;
+#else
+    uint64_t h;
+    uint64_t l;
+#endif
+  } p;
+} t1ha_uint128_t;
+
+static __always_inline t1ha_uint128_t not128(const t1ha_uint128_t v) {
+  t1ha_uint128_t r;
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  r.v = ~v.v;
+#else
+  r.p.l = ~v.p.l;
+  r.p.h = ~v.p.h;
+#endif
+  return r;
+}
+
+static __always_inline t1ha_uint128_t left128(const t1ha_uint128_t v,
+                                              unsigned s) {
+  t1ha_uint128_t r;
+  assert(s < 128);
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  r.v = v.v << s;
+#else
+  r.p.l = (s < 64) ? v.p.l << s : 0;
+  r.p.h = (s < 64) ? (v.p.h << s) | (s ? v.p.l >> (64 - s) : 0) : v.p.l << (s - 64);
+#endif
+  return r;
+}
+
+static __always_inline t1ha_uint128_t right128(const t1ha_uint128_t v,
+                                               unsigned s) {
+  t1ha_uint128_t r;
+  assert(s < 128);
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  r.v = v.v >> s;
+#else
+  r.p.l = (s < 64) ? (s ? v.p.h << (64 - s) : 0) | (v.p.l >> s) : v.p.h >> (s - 64);
+  r.p.h = (s < 64) ? v.p.h >> s : 0;
+#endif
+  return r;
+}
+
+static __always_inline t1ha_uint128_t or128(t1ha_uint128_t x,
+                                            t1ha_uint128_t y) {
+  t1ha_uint128_t r;
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  r.v = x.v | y.v;
+#else
+  r.p.l = x.p.l | y.p.l;
+  r.p.h = x.p.h | y.p.h;
+#endif
+  return r;
+}
+
+static __always_inline t1ha_uint128_t xor128(t1ha_uint128_t x,
+                                             t1ha_uint128_t y) {
+  t1ha_uint128_t r;
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  r.v = x.v ^ y.v;
+#else
+  r.p.l = x.p.l ^ y.p.l;
+  r.p.h = x.p.h ^ y.p.h;
+#endif
+  return r;
+}
+
+static __always_inline t1ha_uint128_t rot128(t1ha_uint128_t v, unsigned s) {
+  s &= 127;
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  v.v = (v.v << (128 - s)) | (v.v >> s);
+  return v;
+#else
+  return s ? or128(left128(v, 128 - s), right128(v, s)) : v;
+#endif
+}
+
+static __always_inline t1ha_uint128_t add128(t1ha_uint128_t x,
+                                             t1ha_uint128_t y) {
+  t1ha_uint128_t r;
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  r.v = x.v + y.v;
+#else
+  add64carry_last(add64carry_first(x.p.l, y.p.l, &r.p.l), x.p.h, y.p.h, &r.p.h);
+#endif
+  return r;
+}
+
+static __always_inline t1ha_uint128_t mul128(t1ha_uint128_t x,
+                                             t1ha_uint128_t y) {
+  t1ha_uint128_t r;
+#if defined(__SIZEOF_INT128__) ||                                              \
+    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
+  r.v = x.v * y.v;
+#else
+  r.p.l = mul_64x64_128(x.p.l, y.p.l, &r.p.h);
+  r.p.h += x.p.l * y.p.h + y.p.l * x.p.h;
+#endif
+  return r;
+}