Down-integrate from internal branch.

Change-Id: Ieb7a2c2fbf35bc2a8fa65b915a5ecb68c83863e4

9 files changed, 1242 insertions, 22 deletions

diff --git a/src/google/protobuf/stubs/common.cc b/src/google/protobuf/stubs/common.cc
index d470fc72..54dbafab 100644
--- a/src/google/protobuf/stubs/common.cc
+++ b/src/google/protobuf/stubs/common.cc
@@ -35,8 +35,10 @@
 #include <google/protobuf/stubs/status.h>
 #include <google/protobuf/stubs/stringpiece.h>
 #include <google/protobuf/stubs/strutil.h>
-#include <stdio.h>
+#include <google/protobuf/stubs/int128.h>
 #include <errno.h>
+#include <sstream>
+#include <stdio.h>
 #include <vector>
 
 #ifdef _WIN32
@@ -48,6 +50,9 @@
 #else
 #error "No suitable threading library available."
 #endif
+#if defined(__ANDROID__)
+#include <android/log.h>
+#endif
 
 namespace google {
 namespace protobuf {
@@ -104,7 +109,43 @@ string VersionString(int version) {
 // emulates google3/base/logging.cc
 
 namespace internal {
+#if defined(__ANDROID__)
+inline void DefaultLogHandler(LogLevel level, const char* filename, int line,
+                              const string& message) {
+#ifdef GOOGLE_PROTOBUF_MIN_LOG_LEVEL
+  if (level < GOOGLE_PROTOBUF_MIN_LOG_LEVEL) {
+    return;
+  }
+  static const char* level_names[] = {"INFO", "WARNING", "ERROR", "FATAL"};
+
+  static const int android_log_levels[] = {
+      ANDROID_LOG_INFO,   // LOG(INFO),
+      ANDROID_LOG_WARN,   // LOG(WARNING)
+      ANDROID_LOG_ERROR,  // LOG(ERROR)
+      ANDROID_LOG_FATAL,  // LOG(FATAL)
+  };
 
+  // Bound the logging level.
+  const int android_log_level = android_log_levels[level];
+  ::std::ostringstream ostr;
+  ostr << "[libprotobuf " << level_names[level] << " " << filename << ":"
+       << line << "] " << message.c_str();
+
+  // Output the log string the Android log at the appropriate level.
+  __android_log_write(android_log_level, "libprotobuf-native",
+                      ostr.str().c_str());
+  // Also output to std::cerr.
+  fprintf(stderr, "%s", ostr.str().c_str());
+  fflush(stderr);
+
+  // Indicate termination if needed.
+  if (android_log_level == ANDROID_LOG_FATAL) {
+    __android_log_write(ANDROID_LOG_FATAL, "libprotobuf-native",
+                        "terminating.\n");
+  }
+#endif
+}
+#else
 void DefaultLogHandler(LogLevel level, const char* filename, int line,
                        const string& message) {
   static const char* level_names[] = { "INFO", "WARNING", "ERROR", "FATAL" };
@@ -115,6 +156,7 @@ void DefaultLogHandler(LogLevel level, const char* filename, int line,
           level_names[level], filename, line, message.c_str());
   fflush(stderr);  // Needed on MSVC.
 }
+#endif
 
 void NullLogHandler(LogLevel /* level */, const char* /* filename */,
                     int /* line */, const string& /* message */) {
@@ -154,22 +196,19 @@ LogMessage& LogMessage::operator<<(const StringPiece& value) {
   return *this;
 }
 
-LogMessage& LogMessage::operator<<(long long value) {
-  message_ += SimpleItoa(value);
-  return *this;
-}
-
-LogMessage& LogMessage::operator<<(unsigned long long value) {
-  message_ += SimpleItoa(value);
-  return *this;
-}
-
 LogMessage& LogMessage::operator<<(
     const ::google::protobuf::util::Status& status) {
   message_ += status.ToString();
   return *this;
 }
 
+LogMessage& LogMessage::operator<<(const uint128& value) {
+  std::ostringstream str;
+  str << value;
+  message_ += str.str();
+  return *this;
+}
+
 // Since this is just for logging, we don't care if the current locale changes
 // the results -- in fact, we probably prefer that.  So we use snprintf()
 // instead of Simple*toa().
@@ -194,6 +233,8 @@ DECLARE_STREAM_OPERATOR(long         , "%ld")
 DECLARE_STREAM_OPERATOR(unsigned long, "%lu")
 DECLARE_STREAM_OPERATOR(double       , "%g" )
 DECLARE_STREAM_OPERATOR(void*        , "%p" )
+DECLARE_STREAM_OPERATOR(long long         , "%" GOOGLE_LL_FORMAT "d")
+DECLARE_STREAM_OPERATOR(unsigned long long, "%" GOOGLE_LL_FORMAT "u")
 #undef DECLARE_STREAM_OPERATOR
 
 LogMessage::LogMessage(LogLevel level, const char* filename, int line)
diff --git a/src/google/protobuf/stubs/common.h b/src/google/protobuf/stubs/common.h
index de866e14..88e7084f 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -35,6 +35,7 @@
 #ifndef GOOGLE_PROTOBUF_COMMON_H__
 #define GOOGLE_PROTOBUF_COMMON_H__
 
+#include <string>
 
 #include <google/protobuf/stubs/port.h>
 #include <google/protobuf/stubs/macros.h>
@@ -137,12 +138,35 @@ std::string LIBPROTOBUF_EXPORT VersionString(int version);
 // ===================================================================
 // from google3/util/utf8/public/unilib.h
 
+class StringPiece;
 namespace internal {
 
 // Checks if the buffer contains structurally-valid UTF-8.  Implemented in
 // structurally_valid.cc.
 LIBPROTOBUF_EXPORT bool IsStructurallyValidUTF8(const char* buf, int len);
 
+inline bool IsStructurallyValidUTF8(const std::string& str) {
+  return IsStructurallyValidUTF8(str.data(), str.length());
+}
+
+// Returns initial number of bytes of structually valid UTF-8.
+LIBPROTOBUF_EXPORT int UTF8SpnStructurallyValid(const StringPiece& str);
+
+// Coerce UTF-8 byte string in src_str to be
+// a structurally-valid equal-length string by selectively
+// overwriting illegal bytes with replace_char (typically ' ' or '?').
+// replace_char must be legal printable 7-bit Ascii 0x20..0x7e.
+// src_str is read-only.
+//
+// Returns pointer to output buffer, src_str.data() if no changes were made,
+//  or idst if some bytes were changed. idst is allocated by the caller
+//  and must be at least as big as src_str
+//
+// Optimized for: all structurally valid and no byte copying is done.
+//
+LIBPROTOBUF_EXPORT char* UTF8CoerceToStructurallyValid(
+    const StringPiece& str, char* dst, char replace_char);
+
 }  // namespace internal
 
 
diff --git a/src/google/protobuf/stubs/hash.h b/src/google/protobuf/stubs/hash.h
index 9a6b217a..0d94ad80 100755
--- a/src/google/protobuf/stubs/hash.h
+++ b/src/google/protobuf/stubs/hash.h
@@ -143,6 +143,21 @@
 # define GOOGLE_PROTOBUF_HASH_SET_CLASS unordered_set
 #endif
 
+#ifndef GOOGLE_PROTOBUF_HASH_NAMESPACE
+# define GOOGLE_PROTOBUF_HASH_NAMESPACE_DECLARATION_START
+# define GOOGLE_PROTOBUF_HASH_NAMESPACE_DECLARATION_END
+#elif !defined(GOOGLE_PROTOBUF_HAS_CXX11_HASH) &&       \
+  defined(GOOGLE_PROTOBUF_HAS_TR1)
+# define GOOGLE_PROTOBUF_HASH_NAMESPACE_DECLARATION_START       \
+  namespace std {                                               \
+  namespace tr1 {
+# define GOOGLE_PROTOBUF_HASH_NAMESPACE_DECLARATION_END }}
+#else
+# define GOOGLE_PROTOBUF_HASH_NAMESPACE_DECLARATION_START       \
+  namespace GOOGLE_PROTOBUF_HASH_NAMESPACE {
+# define GOOGLE_PROTOBUF_HASH_NAMESPACE_DECLARATION_END }
+#endif
+
 #undef GOOGLE_PROTOBUF_HAS_CXX11_HASH
 #undef GOOGLE_PROTOBUF_HAS_TR1
 
diff --git a/src/google/protobuf/stubs/int128.cc b/src/google/protobuf/stubs/int128.cc
new file mode 100644
index 00000000..9f4fb824
--- /dev/null
+++ b/src/google/protobuf/stubs/int128.cc
@@ -0,0 +1,200 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <google/protobuf/stubs/int128.h>
+
+#include <iomanip>
+#include <iostream>  // NOLINT(readability/streams)
+#include <sstream>
+
+namespace google {
+namespace protobuf {
+
+const uint128_pod kuint128max = {
+    static_cast<uint64>(GOOGLE_LONGLONG(0xFFFFFFFFFFFFFFFF)),
+    static_cast<uint64>(GOOGLE_LONGLONG(0xFFFFFFFFFFFFFFFF))
+};
+
+// Returns the 0-based position of the last set bit (i.e., most significant bit)
+// in the given uint64. The argument may not be 0.
+//
+// For example:
+//   Given: 5 (decimal) == 101 (binary)
+//   Returns: 2
+#define STEP(T, n, pos, sh)                   \
+  do {                                        \
+    if ((n) >= (static_cast<T>(1) << (sh))) { \
+      (n) = (n) >> (sh);                      \
+      (pos) |= (sh);                          \
+    }                                         \
+  } while (0)
+static inline int Fls64(uint64 n) {
+  GOOGLE_DCHECK_NE(0, n);
+  int pos = 0;
+  STEP(uint64, n, pos, 0x20);
+  uint32 n32 = n;
+  STEP(uint32, n32, pos, 0x10);
+  STEP(uint32, n32, pos, 0x08);
+  STEP(uint32, n32, pos, 0x04);
+  return pos + ((GOOGLE_ULONGLONG(0x3333333322221100) >> (n32 << 2)) & 0x3);
+}
+#undef STEP
+
+// Like Fls64() above, but returns the 0-based position of the last set bit
+// (i.e., most significant bit) in the given uint128. The argument may not be 0.
+static inline int Fls128(uint128 n) {
+  if (uint64 hi = Uint128High64(n)) {
+    return Fls64(hi) + 64;
+  }
+  return Fls64(Uint128Low64(n));
+}
+
+// Long division/modulo for uint128 implemented using the shift-subtract
+// division algorithm adapted from:
+// http://stackoverflow.com/questions/5386377/division-without-using
+void uint128::DivModImpl(uint128 dividend, uint128 divisor,
+                         uint128* quotient_ret, uint128* remainder_ret) {
+  if (divisor == 0) {
+    GOOGLE_LOG(FATAL) << "Division or mod by zero: dividend.hi=" << dividend.hi_
+                      << ", lo=" << dividend.lo_;
+  }
+
+  if (divisor > dividend) {
+    *quotient_ret = 0;
+    *remainder_ret = dividend;
+    return;
+  }
+
+  if (divisor == dividend) {
+    *quotient_ret = 1;
+    *remainder_ret = 0;
+    return;
+  }
+
+  uint128 denominator = divisor;
+  uint128 position = 1;
+  uint128 quotient = 0;
+
+  // Left aligns the MSB of the denominator and the dividend.
+  int shift = Fls128(dividend) - Fls128(denominator);
+  denominator <<= shift;
+  position <<= shift;
+
+  // Uses shift-subtract algorithm to divide dividend by denominator. The
+  // remainder will be left in dividend.
+  while (position > 0) {
+    if (dividend >= denominator) {
+      dividend -= denominator;
+      quotient |= position;
+    }
+    position >>= 1;
+    denominator >>= 1;
+  }
+
+  *quotient_ret = quotient;
+  *remainder_ret = dividend;
+}
+
+uint128& uint128::operator/=(const uint128& divisor) {
+  uint128 quotient = 0;
+  uint128 remainder = 0;
+  DivModImpl(*this, divisor, &quotient, &remainder);
+  *this = quotient;
+  return *this;
+}
+uint128& uint128::operator%=(const uint128& divisor) {
+  uint128 quotient = 0;
+  uint128 remainder = 0;
+  DivModImpl(*this, divisor, &quotient, &remainder);
+  *this = remainder;
+  return *this;
+}
+
+std::ostream& operator<<(std::ostream& o, const uint128& b) {
+  std::ios_base::fmtflags flags = o.flags();
+
+  // Select a divisor which is the largest power of the base < 2^64.
+  uint128 div;
+  std::streamsize div_base_log;
+  switch (flags & std::ios::basefield) {
+    case std::ios::hex:
+      div = GOOGLE_ULONGLONG(0x1000000000000000);  // 16^15
+      div_base_log = 15;
+      break;
+    case std::ios::oct:
+      div = GOOGLE_ULONGLONG(01000000000000000000000);  // 8^21
+      div_base_log = 21;
+      break;
+    default:  // std::ios::dec
+      div = GOOGLE_ULONGLONG(10000000000000000000);  // 10^19
+      div_base_log = 19;
+      break;
+  }
+
+  // Now piece together the uint128 representation from three chunks of
+  // the original value, each less than "div" and therefore representable
+  // as a uint64.
+  std::ostringstream os;
+  std::ios_base::fmtflags copy_mask =
+      std::ios::basefield | std::ios::showbase | std::ios::uppercase;
+  os.setf(flags & copy_mask, copy_mask);
+  uint128 high = b;
+  uint128 low;
+  uint128::DivModImpl(high, div, &high, &low);
+  uint128 mid;
+  uint128::DivModImpl(high, div, &high, &mid);
+  if (high.lo_ != 0) {
+    os << high.lo_;
+    os << std::noshowbase << std::setfill('0') << std::setw(div_base_log);
+    os << mid.lo_;
+    os << std::setw(div_base_log);
+  } else if (mid.lo_ != 0) {
+    os << mid.lo_;
+    os << std::noshowbase << std::setfill('0') << std::setw(div_base_log);
+  }
+  os << low.lo_;
+  std::string rep = os.str();
+
+  // Add the requisite padding.
+  std::streamsize width = o.width(0);
+  if (width > rep.size()) {
+    if ((flags & std::ios::adjustfield) == std::ios::left) {
+      rep.append(width - rep.size(), o.fill());
+    } else {
+      rep.insert(0, width - rep.size(), o.fill());
+    }
+  }
+
+  // Stream the final representation in a single "<<" call.
+  return o << rep;
+}
+
+}  // namespace protobuf
+}  // namespace google
diff --git a/src/google/protobuf/stubs/int128.h b/src/google/protobuf/stubs/int128.h
new file mode 100644
index 00000000..1e63037f
--- /dev/null
+++ b/src/google/protobuf/stubs/int128.h
@@ -0,0 +1,381 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#ifndef GOOGLE_PROTOBUF_STUBS_INT128_H_
+#define GOOGLE_PROTOBUF_STUBS_INT128_H_
+
+#include <google/protobuf/stubs/common.h>
+
+#include <iosfwd>
+
+namespace google {
+namespace protobuf {
+
+struct uint128_pod;
+
+// TODO(xiaofeng): Define GOOGLE_PROTOBUF_HAS_CONSTEXPR when constexpr is
+// available.
+#ifdef GOOGLE_PROTOBUF_HAS_CONSTEXPR
+# define UINT128_CONSTEXPR constexpr
+#else
+# define UINT128_CONSTEXPR
+#endif
+
+// An unsigned 128-bit integer type. Thread-compatible.
+class uint128 {
+ public:
+  UINT128_CONSTEXPR uint128();  // Sets to 0, but don't trust on this behavior.
+  UINT128_CONSTEXPR uint128(uint64 top, uint64 bottom);
+#ifndef SWIG
+  UINT128_CONSTEXPR uint128(int bottom);
+  UINT128_CONSTEXPR uint128(uint32 bottom);   // Top 96 bits = 0
+#endif
+  UINT128_CONSTEXPR uint128(uint64 bottom);   // hi_ = 0
+  UINT128_CONSTEXPR uint128(const uint128_pod &val);
+
+  // Trivial copy constructor, assignment operator and destructor.
+
+  void Initialize(uint64 top, uint64 bottom);
+
+  // Arithmetic operators.
+  uint128& operator+=(const uint128& b);
+  uint128& operator-=(const uint128& b);
+  uint128& operator*=(const uint128& b);
+  // Long division/modulo for uint128.
+  uint128& operator/=(const uint128& b);
+  uint128& operator%=(const uint128& b);
+  uint128 operator++(int);
+  uint128 operator--(int);
+  uint128& operator<<=(int);
+  uint128& operator>>=(int);
+  uint128& operator&=(const uint128& b);
+  uint128& operator|=(const uint128& b);
+  uint128& operator^=(const uint128& b);
+  uint128& operator++();
+  uint128& operator--();
+
+  friend uint64 Uint128Low64(const uint128& v);
+  friend uint64 Uint128High64(const uint128& v);
+
+  // We add "std::" to avoid including all of port.h.
+  friend std::ostream& operator<<(std::ostream& o, const uint128& b);
+
+ private:
+  static void DivModImpl(uint128 dividend, uint128 divisor,
+                         uint128* quotient_ret, uint128* remainder_ret);
+
+  // Little-endian memory order optimizations can benefit from
+  // having lo_ first, hi_ last.
+  // See util/endian/endian.h and Load128/Store128 for storing a uint128.
+  uint64        lo_;
+  uint64        hi_;
+
+  // Not implemented, just declared for catching automatic type conversions.
+  uint128(uint8);
+  uint128(uint16);
+  uint128(float v);
+  uint128(double v);
+};
+
+// This is a POD form of uint128 which can be used for static variables which
+// need to be operated on as uint128.
+struct uint128_pod {
+  // Note: The ordering of fields is different than 'class uint128' but the
+  // same as its 2-arg constructor.  This enables more obvious initialization
+  // of static instances, which is the primary reason for this struct in the
+  // first place.  This does not seem to defeat any optimizations wrt
+  // operations involving this struct.
+  uint64 hi;
+  uint64 lo;
+};
+
+extern const uint128_pod kuint128max;
+
+// allow uint128 to be logged
+extern std::ostream& operator<<(std::ostream& o, const uint128& b);
+
+// Methods to access low and high pieces of 128-bit value.
+// Defined externally from uint128 to facilitate conversion
+// to native 128-bit types when compilers support them.
+inline uint64 Uint128Low64(const uint128& v) { return v.lo_; }
+inline uint64 Uint128High64(const uint128& v) { return v.hi_; }
+
+// TODO: perhaps it would be nice to have int128, a signed 128-bit type?
+
+// --------------------------------------------------------------------------
+//                      Implementation details follow
+// --------------------------------------------------------------------------
+inline bool operator==(const uint128& lhs, const uint128& rhs) {
+  return (Uint128Low64(lhs) == Uint128Low64(rhs) &&
+          Uint128High64(lhs) == Uint128High64(rhs));
+}
+inline bool operator!=(const uint128& lhs, const uint128& rhs) {
+  return !(lhs == rhs);
+}
+
+inline UINT128_CONSTEXPR uint128::uint128() : lo_(0), hi_(0) {}
+inline UINT128_CONSTEXPR uint128::uint128(uint64 top, uint64 bottom)
+    : lo_(bottom), hi_(top) {}
+inline UINT128_CONSTEXPR uint128::uint128(const uint128_pod& v)
+    : lo_(v.lo), hi_(v.hi) {}
+inline UINT128_CONSTEXPR uint128::uint128(uint64 bottom)
+    : lo_(bottom), hi_(0) {}
+#ifndef SWIG
+inline UINT128_CONSTEXPR uint128::uint128(uint32 bottom)
+    : lo_(bottom), hi_(0) {}
+inline UINT128_CONSTEXPR uint128::uint128(int bottom)
+    : lo_(bottom), hi_(static_cast<int64>((bottom < 0) ? -1 : 0)) {}
+#endif
+
+#undef UINT128_CONSTEXPR
+
+inline void uint128::Initialize(uint64 top, uint64 bottom) {
+  hi_ = top;
+  lo_ = bottom;
+}
+
+// Comparison operators.
+
+#define CMP128(op)                                                \
+inline bool operator op(const uint128& lhs, const uint128& rhs) { \
+  return (Uint128High64(lhs) == Uint128High64(rhs)) ?             \
+      (Uint128Low64(lhs) op Uint128Low64(rhs)) :                  \
+      (Uint128High64(lhs) op Uint128High64(rhs));                 \
+}
+
+CMP128(<)
+CMP128(>)
+CMP128(>=)
+CMP128(<=)
+
+#undef CMP128
+
+// Unary operators
+
+inline uint128 operator-(const uint128& val) {
+  const uint64 hi_flip = ~Uint128High64(val);
+  const uint64 lo_flip = ~Uint128Low64(val);
+  const uint64 lo_add = lo_flip + 1;
+  if (lo_add < lo_flip) {
+    return uint128(hi_flip + 1, lo_add);
+  }
+  return uint128(hi_flip, lo_add);
+}
+
+inline bool operator!(const uint128& val) {
+  return !Uint128High64(val) && !Uint128Low64(val);
+}
+
+// Logical operators.
+
+inline uint128 operator~(const uint128& val) {
+  return uint128(~Uint128High64(val), ~Uint128Low64(val));
+}
+
+#define LOGIC128(op)                                                 \
+inline uint128 operator op(const uint128& lhs, const uint128& rhs) { \
+  return uint128(Uint128High64(lhs) op Uint128High64(rhs),           \
+                 Uint128Low64(lhs) op Uint128Low64(rhs));            \
+}
+
+LOGIC128(|)
+LOGIC128(&)
+LOGIC128(^)
+
+#undef LOGIC128
+
+#define LOGICASSIGN128(op)                                   \
+inline uint128& uint128::operator op(const uint128& other) { \
+  hi_ op other.hi_;                                          \
+  lo_ op other.lo_;                                          \
+  return *this;                                              \
+}
+
+LOGICASSIGN128(|=)
+LOGICASSIGN128(&=)
+LOGICASSIGN128(^=)
+
+#undef LOGICASSIGN128
+
+// Shift operators.
+
+inline uint128 operator<<(const uint128& val, int amount) {
+  // uint64 shifts of >= 64 are undefined, so we will need some special-casing.
+  if (amount < 64) {
+    if (amount == 0) {
+      return val;
+    }
+    uint64 new_hi = (Uint128High64(val) << amount) |
+                    (Uint128Low64(val) >> (64 - amount));
+    uint64 new_lo = Uint128Low64(val) << amount;
+    return uint128(new_hi, new_lo);
+  } else if (amount < 128) {
+    return uint128(Uint128Low64(val) << (amount - 64), 0);
+  } else {
+    return uint128(0, 0);
+  }
+}
+
+inline uint128 operator>>(const uint128& val, int amount) {
+  // uint64 shifts of >= 64 are undefined, so we will need some special-casing.
+  if (amount < 64) {
+    if (amount == 0) {
+      return val;
+    }
+    uint64 new_hi = Uint128High64(val) >> amount;
+    uint64 new_lo = (Uint128Low64(val) >> amount) |
+                    (Uint128High64(val) << (64 - amount));
+    return uint128(new_hi, new_lo);
+  } else if (amount < 128) {
+    return uint128(0, Uint128High64(val) >> (amount - 64));
+  } else {
+    return uint128(0, 0);
+  }
+}
+
+inline uint128& uint128::operator<<=(int amount) {
+  // uint64 shifts of >= 64 are undefined, so we will need some special-casing.
+  if (amount < 64) {
+    if (amount != 0) {
+      hi_ = (hi_ << amount) | (lo_ >> (64 - amount));
+      lo_ = lo_ << amount;
+    }
+  } else if (amount < 128) {
+    hi_ = lo_ << (amount - 64);
+    lo_ = 0;
+  } else {
+    hi_ = 0;
+    lo_ = 0;
+  }
+  return *this;
+}
+
+inline uint128& uint128::operator>>=(int amount) {
+  // uint64 shifts of >= 64 are undefined, so we will need some special-casing.
+  if (amount < 64) {
+    if (amount != 0) {
+      lo_ = (lo_ >> amount) | (hi_ << (64 - amount));
+      hi_ = hi_ >> amount;
+    }
+  } else if (amount < 128) {
+    lo_ = hi_ >> (amount - 64);
+    hi_ = 0;
+  } else {
+    lo_ = 0;
+    hi_ = 0;
+  }
+  return *this;
+}
+
+inline uint128 operator+(const uint128& lhs, const uint128& rhs) {
+  return uint128(lhs) += rhs;
+}
+
+inline uint128 operator-(const uint128& lhs, const uint128& rhs) {
+  return uint128(lhs) -= rhs;
+}
+
+inline uint128 operator*(const uint128& lhs, const uint128& rhs) {
+  return uint128(lhs) *= rhs;
+}
+
+inline uint128 operator/(const uint128& lhs, const uint128& rhs) {
+  return uint128(lhs) /= rhs;
+}
+
+inline uint128 operator%(const uint128& lhs, const uint128& rhs) {
+  return uint128(lhs) %= rhs;
+}
+
+inline uint128& uint128::operator+=(const uint128& b) {
+  hi_ += b.hi_;
+  uint64 lolo = lo_ + b.lo_;
+  if (lolo < lo_)
+    ++hi_;
+  lo_ = lolo;
+  return *this;
+}
+
+inline uint128& uint128::operator-=(const uint128& b) {
+  hi_ -= b.hi_;
+  if (b.lo_ > lo_)
+    --hi_;
+  lo_ -= b.lo_;
+  return *this;
+}
+
+inline uint128& uint128::operator*=(const uint128& b) {
+  uint64 a96 = hi_ >> 32;
+  uint64 a64 = hi_ & 0xffffffffu;
+  uint64 a32 = lo_ >> 32;
+  uint64 a00 = lo_ & 0xffffffffu;
+  uint64 b96 = b.hi_ >> 32;
+  uint64 b64 = b.hi_ & 0xffffffffu;
+  uint64 b32 = b.lo_ >> 32;
+  uint64 b00 = b.lo_ & 0xffffffffu;
+  // multiply [a96 .. a00] x [b96 .. b00]
+  // terms higher than c96 disappear off the high side
+  // terms c96 and c64 are safe to ignore carry bit
+  uint64 c96 = a96 * b00 + a64 * b32 + a32 * b64 + a00 * b96;
+  uint64 c64 = a64 * b00 + a32 * b32 + a00 * b64;
+  this->hi_ = (c96 << 32) + c64;
+  this->lo_ = 0;
+  // add terms after this one at a time to capture carry
+  *this += uint128(a32 * b00) << 32;
+  *this += uint128(a00 * b32) << 32;
+  *this += a00 * b00;
+  return *this;
+}
+
+inline uint128 uint128::operator++(int) {
+  uint128 tmp(*this);
+  *this += 1;
+  return tmp;
+}
+
+inline uint128 uint128::operator--(int) {
+  uint128 tmp(*this);
+  *this -= 1;
+  return tmp;
+}
+
+inline uint128& uint128::operator++() {
+  *this += 1;
+  return *this;
+}
+
+inline uint128& uint128::operator--() {
+  *this -= 1;
+  return *this;
+}
+
+}  // namespace protobuf
+}  // namespace google
+
+#endif  // GOOGLE_PROTOBUF_STUBS_INT128_H_
diff --git a/src/google/protobuf/stubs/int128_unittest.cc b/src/google/protobuf/stubs/int128_unittest.cc
new file mode 100644
index 00000000..5d33292c
--- /dev/null
+++ b/src/google/protobuf/stubs/int128_unittest.cc
@@ -0,0 +1,513 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <google/protobuf/stubs/int128.h>
+
+#include <algorithm>
+#include <sstream>
+#include <utility>
+
+#include <google/protobuf/testing/googletest.h>
+#include <gtest/gtest.h>
+
+namespace google {
+namespace protobuf {
+
+TEST(Int128, AllTests) {
+  uint128 zero(0);
+  uint128 one(1);
+  uint128 one_2arg(0, 1);
+  uint128 two(0, 2);
+  uint128 three(0, 3);
+  uint128 big(2000, 2);
+  uint128 big_minus_one(2000, 1);
+  uint128 bigger(2001, 1);
+  uint128 biggest(kuint128max);
+  uint128 high_low(1, 0);
+  uint128 low_high(0, kuint64max);
+  EXPECT_LT(one, two);
+  EXPECT_GT(two, one);
+  EXPECT_LT(one, big);
+  EXPECT_LT(one, big);
+  EXPECT_EQ(one, one_2arg);
+  EXPECT_NE(one, two);
+  EXPECT_GT(big, one);
+  EXPECT_GE(big, two);
+  EXPECT_GE(big, big_minus_one);
+  EXPECT_GT(big, big_minus_one);
+  EXPECT_LT(big_minus_one, big);
+  EXPECT_LE(big_minus_one, big);
+  EXPECT_NE(big_minus_one, big);
+  EXPECT_LT(big, biggest);
+  EXPECT_LE(big, biggest);
+  EXPECT_GT(biggest, big);
+  EXPECT_GE(biggest, big);
+  EXPECT_EQ(big, ~~big);
+  EXPECT_EQ(one, one | one);
+  EXPECT_EQ(big, big | big);
+  EXPECT_EQ(one, one | zero);
+  EXPECT_EQ(one, one & one);
+  EXPECT_EQ(big, big & big);
+  EXPECT_EQ(zero, one & zero);
+  EXPECT_EQ(zero, big & ~big);
+  EXPECT_EQ(zero, one ^ one);
+  EXPECT_EQ(zero, big ^ big);
+  EXPECT_EQ(one, one ^ zero);
+
+  // Shift operators.
+  EXPECT_EQ(big, big << 0);
+  EXPECT_EQ(big, big >> 0);
+  EXPECT_GT(big << 1, big);
+  EXPECT_LT(big >> 1, big);
+  EXPECT_EQ(big, (big << 10) >> 10);
+  EXPECT_EQ(big, (big >> 1) << 1);
+  EXPECT_EQ(one, (one << 80) >> 80);
+  EXPECT_EQ(zero, (one >> 80) << 80);
+  EXPECT_EQ(zero, big >> 128);
+  EXPECT_EQ(zero, big << 128);
+
+  // Shift assignments.
+  uint128 big_copy = big;
+  EXPECT_EQ(big << 0, big_copy <<= 0);
+  big_copy = big;
+  EXPECT_EQ(big >> 0, big_copy >>= 0);
+  big_copy = big;
+  EXPECT_EQ(big << 1, big_copy <<= 1);
+  big_copy = big;
+  EXPECT_EQ(big >> 1, big_copy >>= 1);
+  big_copy = big;
+  EXPECT_EQ(big << 10, big_copy <<= 10);
+  big_copy = big;
+  EXPECT_EQ(big >> 10, big_copy >>= 10);
+  big_copy = big;
+  EXPECT_EQ(big << 64, big_copy <<= 64);
+  big_copy = big;
+  EXPECT_EQ(big >> 64, big_copy >>= 64);
+  big_copy = big;
+  EXPECT_EQ(big << 73, big_copy <<= 73);
+  big_copy = big;
+  EXPECT_EQ(big >> 73, big_copy >>= 73);
+  big_copy = big;
+  EXPECT_EQ(big << 128, big_copy <<= 128);
+  big_copy = big;
+  EXPECT_EQ(big >> 128, big_copy >>= 128);
+
+  EXPECT_EQ(Uint128High64(biggest), kuint64max);
+  EXPECT_EQ(Uint128Low64(biggest), kuint64max);
+  EXPECT_EQ(zero + one, one);
+  EXPECT_EQ(one + one, two);
+  EXPECT_EQ(big_minus_one + one, big);
+  EXPECT_EQ(one - one, zero);
+  EXPECT_EQ(one - zero, one);
+  EXPECT_EQ(zero - one, biggest);
+  EXPECT_EQ(big - big, zero);
+  EXPECT_EQ(big - one, big_minus_one);
+  EXPECT_EQ(big + kuint64max, bigger);
+  EXPECT_EQ(biggest + 1, zero);
+  EXPECT_EQ(zero - 1, biggest);
+  EXPECT_EQ(high_low - one, low_high);
+  EXPECT_EQ(low_high + one, high_low);
+  EXPECT_EQ(Uint128High64((uint128(1) << 64) - 1), 0);
+  EXPECT_EQ(Uint128Low64((uint128(1) << 64) - 1), kuint64max);
+  EXPECT_TRUE(!!one);
+  EXPECT_TRUE(!!high_low);
+  EXPECT_FALSE(!!zero);
+  EXPECT_FALSE(!one);
+  EXPECT_FALSE(!high_low);
+  EXPECT_TRUE(!zero);
+  EXPECT_TRUE(zero == 0);
+  EXPECT_FALSE(zero != 0);
+  EXPECT_FALSE(one == 0);
+  EXPECT_TRUE(one != 0);
+
+  uint128 test = zero;
+  EXPECT_EQ(++test, one);
+  EXPECT_EQ(test, one);
+  EXPECT_EQ(test++, one);
+  EXPECT_EQ(test, two);
+  EXPECT_EQ(test -= 2, zero);
+  EXPECT_EQ(test, zero);
+  EXPECT_EQ(test += 2, two);
+  EXPECT_EQ(test, two);
+  EXPECT_EQ(--test, one);
+  EXPECT_EQ(test, one);
+  EXPECT_EQ(test--, one);
+  EXPECT_EQ(test, zero);
+  EXPECT_EQ(test |= three, three);
+  EXPECT_EQ(test &= one, one);
+  EXPECT_EQ(test ^= three, two);
+  EXPECT_EQ(test >>= 1, one);
+  EXPECT_EQ(test <<= 1, two);
+
+  EXPECT_EQ(big, -(-big));
+  EXPECT_EQ(two, -((-one) - 1));
+  EXPECT_EQ(kuint128max, -one);
+  EXPECT_EQ(zero, -zero);
+
+  GOOGLE_LOG(INFO) << one;
+  GOOGLE_LOG(INFO) << big_minus_one;
+}
+
+TEST(Int128, PodTests) {
+  uint128_pod pod = { 12345, 67890 };
+  uint128 from_pod(pod);
+  EXPECT_EQ(12345, Uint128High64(from_pod));
+  EXPECT_EQ(67890, Uint128Low64(from_pod));
+
+  uint128 zero(0);
+  uint128_pod zero_pod = {0, 0};
+  uint128 one(1);
+  uint128_pod one_pod = {0, 1};
+  uint128 two(2);
+  uint128_pod two_pod = {0, 2};
+  uint128 three(3);
+  uint128_pod three_pod = {0, 3};
+  uint128 big(1, 0);
+  uint128_pod big_pod = {1, 0};
+
+  EXPECT_EQ(zero, zero_pod);
+  EXPECT_EQ(zero_pod, zero);
+  EXPECT_EQ(zero_pod, zero_pod);
+  EXPECT_EQ(one, one_pod);
+  EXPECT_EQ(one_pod, one);
+  EXPECT_EQ(one_pod, one_pod);
+  EXPECT_EQ(two, two_pod);
+  EXPECT_EQ(two_pod, two);
+  EXPECT_EQ(two_pod, two_pod);
+
+  EXPECT_NE(one, two_pod);
+  EXPECT_NE(one_pod, two);
+  EXPECT_NE(one_pod, two_pod);
+
+  EXPECT_LT(one, two_pod);
+  EXPECT_LT(one_pod, two);
+  EXPECT_LT(one_pod, two_pod);
+  EXPECT_LE(one, one_pod);
+  EXPECT_LE(one_pod, one);
+  EXPECT_LE(one_pod, one_pod);
+  EXPECT_LE(one, two_pod);
+  EXPECT_LE(one_pod, two);
+  EXPECT_LE(one_pod, two_pod);
+
+  EXPECT_GT(two, one_pod);
+  EXPECT_GT(two_pod, one);
+  EXPECT_GT(two_pod, one_pod);
+  EXPECT_GE(two, two_pod);
+  EXPECT_GE(two_pod, two);
+  EXPECT_GE(two_pod, two_pod);
+  EXPECT_GE(two, one_pod);
+  EXPECT_GE(two_pod, one);
+  EXPECT_GE(two_pod, one_pod);
+
+  EXPECT_EQ(three, one | two_pod);
+  EXPECT_EQ(three, one_pod | two);
+  EXPECT_EQ(three, one_pod | two_pod);
+  EXPECT_EQ(one, three & one_pod);
+  EXPECT_EQ(one, three_pod & one);
+  EXPECT_EQ(one, three_pod & one_pod);
+  EXPECT_EQ(two, three ^ one_pod);
+  EXPECT_EQ(two, three_pod ^ one);
+  EXPECT_EQ(two, three_pod ^ one_pod);
+  EXPECT_EQ(two, three & (~one));
+  EXPECT_EQ(three, ~~three);
+
+  EXPECT_EQ(two, two_pod << 0);
+  EXPECT_EQ(two, one_pod << 1);
+  EXPECT_EQ(big, one_pod << 64);
+  EXPECT_EQ(zero, one_pod << 128);
+  EXPECT_EQ(two, two_pod >> 0);
+  EXPECT_EQ(one, two_pod >> 1);
+  EXPECT_EQ(one, big_pod >> 64);
+
+  EXPECT_EQ(one, zero + one_pod);
+  EXPECT_EQ(one, zero_pod + one);
+  EXPECT_EQ(one, zero_pod + one_pod);
+  EXPECT_EQ(one, two - one_pod);
+  EXPECT_EQ(one, two_pod - one);
+  EXPECT_EQ(one, two_pod - one_pod);
+}
+
+TEST(Int128, OperatorAssignReturnRef) {
+  uint128 v(1);
+  (v += 4) -= 3;
+  EXPECT_EQ(2, v);
+}
+
+TEST(Int128, Multiply) {
+  uint128 a, b, c;
+
+  // Zero test.
+  a = 0;
+  b = 0;
+  c = a * b;
+  EXPECT_EQ(0, c);
+
+  // Max carries.
+  a = uint128(0) - 1;
+  b = uint128(0) - 1;
+  c = a * b;
+  EXPECT_EQ(1, c);
+
+  // Self-operation with max carries.
+  c = uint128(0) - 1;
+  c *= c;
+  EXPECT_EQ(1, c);
+
+  // 1-bit x 1-bit.
+  for (int i = 0; i < 64; ++i) {
+    for (int j = 0; j < 64; ++j) {
+      a = uint128(1) << i;
+      b = uint128(1) << j;
+      c = a * b;
+      EXPECT_EQ(uint128(1) << (i+j), c);
+    }
+  }
+
+  // Verified with dc.
+  a = uint128(GOOGLE_ULONGLONG(0xffffeeeeddddcccc),
+              GOOGLE_ULONGLONG(0xbbbbaaaa99998888));
+  b = uint128(GOOGLE_ULONGLONG(0x7777666655554444),
+              GOOGLE_ULONGLONG(0x3333222211110000));
+  c = a * b;
+  EXPECT_EQ(uint128(GOOGLE_ULONGLONG(0x530EDA741C71D4C3),
+                    GOOGLE_ULONGLONG(0xBF25975319080000)), c);
+  EXPECT_EQ(0, c - b * a);
+  EXPECT_EQ(a*a - b*b, (a+b) * (a-b));
+
+  // Verified with dc.
+  a = uint128(GOOGLE_ULONGLONG(0x0123456789abcdef),
+              GOOGLE_ULONGLONG(0xfedcba9876543210));
+  b = uint128(GOOGLE_ULONGLONG(0x02468ace13579bdf),
+              GOOGLE_ULONGLONG(0xfdb97531eca86420));
+  c = a * b;
+  EXPECT_EQ(uint128(GOOGLE_ULONGLONG(0x97a87f4f261ba3f2),
+                    GOOGLE_ULONGLONG(0x342d0bbf48948200)), c);
+  EXPECT_EQ(0, c - b * a);
+  EXPECT_EQ(a*a - b*b, (a+b) * (a-b));
+}
+
+TEST(Int128, AliasTests) {
+  uint128 x1(1, 2);
+  uint128 x2(2, 4);
+  x1 += x1;
+  EXPECT_EQ(x2, x1);
+
+  uint128 x3(1, static_cast<uint64>(1) << 63);
+  uint128 x4(3, 0);
+  x3 += x3;
+  EXPECT_EQ(x4, x3);
+}
+
+#ifdef PROTOBUF_HAS_DEATH_TEST
+TEST(Int128, DivideByZeroCheckFails) {
+  uint128 a = 0;
+  uint128 b = 0;
+  EXPECT_DEATH(a / b, "Division or mod by zero:");
+  a = 123;
+  EXPECT_DEATH(a / b, "Division or mod by zero:");
+}
+
+TEST(Int128, ModByZeroCheckFails) {
+  uint128 a = 0;
+  uint128 b = 0;
+  EXPECT_DEATH(a % b, "Division or mod by zero:");
+  a = 123;
+  EXPECT_DEATH(a % b, "Division or mod by zero:");
+}
+#endif  // PROTOBUF_HAS_DEATH_TEST
+
+TEST(Int128, DivideAndMod) {
+  // a := q * b + r
+  uint128 a, b, q, r;
+
+  // Zero test.
+  a = 0;
+  b = 123;
+  q = a / b;
+  r = a % b;
+  EXPECT_EQ(0, q);
+  EXPECT_EQ(0, r);
+
+  a = uint128(GOOGLE_ULONGLONG(0x530eda741c71d4c3),
+              GOOGLE_ULONGLONG(0xbf25975319080000));
+  q = uint128(GOOGLE_ULONGLONG(0x4de2cab081),
+              GOOGLE_ULONGLONG(0x14c34ab4676e4bab));
+  b = uint128(0x1110001);
+  r = uint128(0x3eb455);
+  ASSERT_EQ(a, q * b + r);  // Sanity-check.
+
+  uint128 result_q, result_r;
+  result_q = a / b;
+  result_r = a % b;
+  EXPECT_EQ(q, result_q);
+  EXPECT_EQ(r, result_r);
+
+  // Try the other way around.
+  swap(q, b);
+  result_q = a / b;
+  result_r = a % b;
+  EXPECT_EQ(q, result_q);
+  EXPECT_EQ(r, result_r);
+  // Restore.
+  swap(b, q);
+
+  // Dividend < divisor; result should be q:0 r:<dividend>.
+  swap(a, b);
+  result_q = a / b;
+  result_r = a % b;
+  EXPECT_EQ(0, result_q);
+  EXPECT_EQ(a, result_r);
+  // Try the other way around.
+  swap(a, q);
+  result_q = a / b;
+  result_r = a % b;
+  EXPECT_EQ(0, result_q);
+  EXPECT_EQ(a, result_r);
+  // Restore.
+  swap(q, a);
+  swap(b, a);
+
+  // Try a large remainder.
+  b = a / 2 + 1;
+  uint128 expected_r(GOOGLE_ULONGLONG(0x29876d3a0e38ea61),
+                     GOOGLE_ULONGLONG(0xdf92cba98c83ffff));
+  // Sanity checks.
+  ASSERT_EQ(a / 2 - 1, expected_r);
+  ASSERT_EQ(a, b + expected_r);
+  result_q = a / b;
+  result_r = a % b;
+  EXPECT_EQ(1, result_q);
+  EXPECT_EQ(expected_r, result_r);
+}
+
+static uint64 RandomUint64() {
+  uint64 v1 = rand();
+  uint64 v2 = rand();
+  uint64 v3 = rand();
+  return v1 * v2 + v3;
+}
+
+TEST(Int128, DivideAndModRandomInputs) {
+  const int kNumIters = 1 << 18;
+  for (int i = 0; i < kNumIters; ++i) {
+    const uint128 a(RandomUint64(), RandomUint64());
+    const uint128 b(RandomUint64(), RandomUint64());
+    if (b == 0) {
+      continue;  // Avoid a div-by-zero.
+    }
+    const uint128 q = a / b;
+    const uint128 r = a % b;
+    ASSERT_EQ(a, b * q + r);
+  }
+}
+
+#ifdef GOOGLE_PROTOBUF_HAS_CONSTEXPR
+TEST(Int128, ConstexprTest) {
+  constexpr uint128 zero;
+  constexpr uint128 one = 1;
+  constexpr uint128_pod pod = {2, 3};
+  constexpr uint128 from_pod = pod;
+  constexpr uint128 minus_two = -2;
+  EXPECT_EQ(one, uint128(1));
+  EXPECT_EQ(from_pod, uint128(2, 3));
+  EXPECT_EQ(minus_two, uint128(-1ULL, -2ULL));
+}
+
+TEST(Int128, Traits) {
+  EXPECT_TRUE(std::is_trivially_copy_constructible<uint128>::value);
+  EXPECT_TRUE(std::is_trivially_copy_assignable<uint128>::value);
+  EXPECT_TRUE(std::is_trivially_destructible<uint128>::value);
+}
+#endif  // GOOGLE_PROTOBUF_HAS_CONSTEXPR
+
+TEST(Int128, OStream) {
+  struct {
+    uint128 val;
+    std::ios_base::fmtflags flags;
+    std::streamsize width;
+    char fill;
+    const char* rep;
+  } cases[] = {
+        // zero with different bases
+        {uint128(0), std::ios::dec, 0, '_', "0"},
+        {uint128(0), std::ios::oct, 0, '_', "0"},
+        {uint128(0), std::ios::hex, 0, '_', "0"},
+        // crossover between lo_ and hi_
+        {uint128(0, -1), std::ios::dec, 0, '_', "18446744073709551615"},
+        {uint128(0, -1), std::ios::oct, 0, '_', "1777777777777777777777"},
+        {uint128(0, -1), std::ios::hex, 0, '_', "ffffffffffffffff"},
+        {uint128(1, 0), std::ios::dec, 0, '_', "18446744073709551616"},
+        {uint128(1, 0), std::ios::oct, 0, '_', "2000000000000000000000"},
+        {uint128(1, 0), std::ios::hex, 0, '_', "10000000000000000"},
+        // just the top bit
+        {uint128(GOOGLE_ULONGLONG(0x8000000000000000), 0), std::ios::dec, 0, '_',
+         "170141183460469231731687303715884105728"},
+        {uint128(GOOGLE_ULONGLONG(0x8000000000000000), 0), std::ios::oct, 0, '_',
+         "2000000000000000000000000000000000000000000"},
+        {uint128(GOOGLE_ULONGLONG(0x8000000000000000), 0), std::ios::hex, 0, '_',
+         "80000000000000000000000000000000"},
+        // maximum uint128 value
+        {uint128(-1, -1), std::ios::dec, 0, '_',
+         "340282366920938463463374607431768211455"},
+        {uint128(-1, -1), std::ios::oct, 0, '_',
+         "3777777777777777777777777777777777777777777"},
+        {uint128(-1, -1), std::ios::hex, 0, '_',
+         "ffffffffffffffffffffffffffffffff"},
+        // uppercase
+        {uint128(-1, -1), std::ios::hex | std::ios::uppercase, 0, '_',
+         "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"},
+        // showbase
+        {uint128(1), std::ios::dec | std::ios::showbase, 0, '_', "1"},
+        {uint128(1), std::ios::oct | std::ios::showbase, 0, '_', "01"},
+        {uint128(1), std::ios::hex | std::ios::showbase, 0, '_', "0x1"},
+        // showbase does nothing on zero
+        {uint128(0), std::ios::dec | std::ios::showbase, 0, '_', "0"},
+        {uint128(0), std::ios::oct | std::ios::showbase, 0, '_', "0"},
+        {uint128(0), std::ios::hex | std::ios::showbase, 0, '_', "0"},
+        // showpos does nothing on unsigned types
+        {uint128(1), std::ios::dec | std::ios::showpos, 0, '_', "1"},
+        // padding
+        {uint128(9), std::ios::dec, 6, '_', "_____9"},
+        {uint128(12345), std::ios::dec, 6, '_', "_12345"},
+        // left adjustment
+        {uint128(9), std::ios::dec | std::ios::left, 6, '_', "9_____"},
+        {uint128(12345), std::ios::dec | std::ios::left, 6, '_', "12345_"},
+  };
+  for (size_t i = 0; i < GOOGLE_ARRAYSIZE(cases); ++i) {
+    ostringstream os;
+    os.flags(cases[i].flags);
+    os.width(cases[i].width);
+    os.fill(cases[i].fill);
+    os << cases[i].val;
+    EXPECT_EQ(cases[i].rep, os.str());
+  }
+}
+}  // namespace protobuf
+}  // namespace google
diff --git a/src/google/protobuf/stubs/logging.h b/src/google/protobuf/stubs/logging.h
index 330d33d2..3108db8c 100644
--- a/src/google/protobuf/stubs/logging.h
+++ b/src/google/protobuf/stubs/logging.h
@@ -65,6 +65,7 @@ class StringPiece;
 namespace util {
 class Status;
 }
+class uint128;
 namespace internal {
 
 class LogFinisher;
@@ -78,7 +79,7 @@ class LIBPROTOBUF_EXPORT LogMessage {
   LogMessage& operator<<(const char* value);
   LogMessage& operator<<(char value);
   LogMessage& operator<<(int value);
-  LogMessage& operator<<(unsigned int value);
+  LogMessage& operator<<(uint value);
   LogMessage& operator<<(long value);
   LogMessage& operator<<(unsigned long value);
   LogMessage& operator<<(long long value);
@@ -87,6 +88,7 @@ class LIBPROTOBUF_EXPORT LogMessage {
   LogMessage& operator<<(void* value);
   LogMessage& operator<<(const StringPiece& value);
   LogMessage& operator<<(const ::google::protobuf::util::Status& status);
+  LogMessage& operator<<(const uint128& value);
 
  private:
   friend class LogFinisher;
diff --git a/src/google/protobuf/stubs/port.h b/src/google/protobuf/stubs/port.h
index c86cf35b..7d84b92f 100644
--- a/src/google/protobuf/stubs/port.h
+++ b/src/google/protobuf/stubs/port.h
@@ -100,20 +100,12 @@ typedef unsigned __int64 uint64;
 typedef signed char  int8;
 typedef short int16;
 typedef int int32;
-// NOTE: This should be "long long" for consistency with upstream, but
-// something is stacked against this particular type for 64bit hashing.
-// Switching it causes an obvious missing hash function (with an unobvious
-// cause) when building the tests.
-typedef int64_t int64;
+typedef long long int64;
 
 typedef unsigned char  uint8;
 typedef unsigned short uint16;
 typedef unsigned int uint32;
-// NOTE: This should be "unsigned long long" for consistency with upstream, but
-// something is stacked against this particular type for 64bit hashing.
-// Switching it causes an obvious missing hash function (with an unobvious
-// cause) when building the tests.
-typedef uint64_t uint64;
+typedef unsigned long long uint64;
 #endif
 
 // long long macros to be used because gcc and vc++ use different suffixes,
diff --git a/src/google/protobuf/stubs/structurally_valid.cc b/src/google/protobuf/stubs/structurally_valid.cc
index 0f6afe6d..d79a6ee4 100644
--- a/src/google/protobuf/stubs/structurally_valid.cc
+++ b/src/google/protobuf/stubs/structurally_valid.cc
@@ -3,6 +3,8 @@
 
 #include <google/protobuf/stubs/common.h>
 
+#include <google/protobuf/stubs/stringpiece.h>
+
 namespace google {
 namespace protobuf {
 namespace internal {
@@ -531,6 +533,56 @@ bool IsStructurallyValidUTF8(const char* buf, int len) {
   return (bytes_consumed == len);
 }
 
+int UTF8SpnStructurallyValid(const StringPiece& str) {
+  if (!module_initialized_) return str.size();
+
+  int bytes_consumed = 0;
+  UTF8GenericScanFastAscii(&utf8acceptnonsurrogates_obj,
+                           str.data(), str.size(), &bytes_consumed);
+  return bytes_consumed;
+}
+
+// Coerce UTF-8 byte string in src_str to be
+// a structurally-valid equal-length string by selectively
+// overwriting illegal bytes with replace_char (typically blank).
+// replace_char must be legal printable 7-bit Ascii 0x20..0x7e.
+// src_str is read-only. If any overwriting is needed, a modified byte string
+// is created in idst, length isrclen.
+//
+// Returns pointer to output buffer, isrc if no changes were made,
+//  or idst if some bytes were changed.
+//
+// Fast case: all is structurally valid and no byte copying is done.
+//
+char* UTF8CoerceToStructurallyValid(const StringPiece& src_str,
+                                    char* idst,
+                                    const char replace_char) {
+  const char* isrc = src_str.data();
+  const int len = src_str.length();
+  int n = UTF8SpnStructurallyValid(src_str);
+  if (n == len) {               // Normal case -- all is cool, return
+    return const_cast<char*>(isrc);
+  } else {                      // Unusual case -- copy w/o bad bytes
+    const char* src = isrc;
+    const char* srclimit = isrc + len;
+    char* dst = idst;
+    memmove(dst, src, n);       // Copy initial good chunk
+    src += n;
+    dst += n;
+    while (src < srclimit) {    // src points to bogus byte or is off the end
+      dst[0] = replace_char;                    // replace one bad byte
+      src++;
+      dst++;
+      StringPiece str2(src, srclimit - src);
+      n = UTF8SpnStructurallyValid(str2);       // scan the remainder
+      memmove(dst, src, n);                     // copy next good chunk
+      src += n;
+      dst += n;
+    }
+  }
+  return idst;
+}
+
 }  // namespace internal
 }  // namespace protobuf
 }  // namespace google