Update //third_party/protobuf to version 3.

third_party/protobuf/src/google/protobuf/stubs/fastmem.h

Index: third_party/protobuf/src/google/protobuf/stubs/fastmem.h
diff --git a/third_party/protobuf/src/google/protobuf/stubs/fastmem.h b/third_party/protobuf/src/google/protobuf/stubs/fastmem.h
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index 0000000000000000000000000000000000000000..763a6e6024bc4b20fd566421a3b4d340a79f03d6
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+// Protocol Buffers - Google's data interchange format
+// Copyright 2014 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.
+
+// Fast memory copying and comparison routines.
+//   strings::fastmemcmp_inlined() replaces memcmp()
+//   strings::memcpy_inlined() replaces memcpy()
+//   strings::memeq(a, b, n) replaces memcmp(a, b, n) == 0
+//
+// strings::*_inlined() routines are inline versions of the
+// routines exported by this module.  Sometimes using the inlined
+// versions is faster.  Measure before using the inlined versions.
+//
+// Performance measurement:
+//   strings::fastmemcmp_inlined
+//     Analysis: memcmp, fastmemcmp_inlined, fastmemcmp
+//     2012-01-30
+
+#ifndef GOOGLE_PROTOBUF_STUBS_FASTMEM_H_
+#define GOOGLE_PROTOBUF_STUBS_FASTMEM_H_
+
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <google/protobuf/stubs/common.h>
+
+namespace google {
+namespace protobuf {
+namespace internal {
+
+// Return true if the n bytes at a equal the n bytes at b.
+// The regions are allowed to overlap.
+//
+// The performance is similar to the performance memcmp(), but faster for
+// moderately-sized inputs, or inputs that share a common prefix and differ
+// somewhere in their last 8 bytes. Further optimizations can be added later
+// if it makes sense to do so.:w
+inline bool memeq(const char* a, const char* b, size_t n) {
+  size_t n_rounded_down = n & ~static_cast<size_t>(7);
+  if (GOOGLE_PREDICT_FALSE(n_rounded_down == 0)) {  // n <= 7
+    return memcmp(a, b, n) == 0;
+  }
+  // n >= 8
+  uint64 u = GOOGLE_UNALIGNED_LOAD64(a) ^ GOOGLE_UNALIGNED_LOAD64(b);
+  uint64 v = GOOGLE_UNALIGNED_LOAD64(a + n - 8) ^ GOOGLE_UNALIGNED_LOAD64(b + n - 8);
+  if ((u | v) != 0) {  // The first or last 8 bytes differ.
+    return false;
+  }
+  a += 8;
+  b += 8;
+  n = n_rounded_down - 8;
+  if (n > 128) {
+    // As of 2012, memcmp on x86-64 uses a big unrolled loop with SSE2
+    // instructions, and while we could try to do something faster, it
+    // doesn't seem worth pursuing.
+    return memcmp(a, b, n) == 0;
+  }
+  for (; n >= 16; n -= 16) {
+    uint64 x = GOOGLE_UNALIGNED_LOAD64(a) ^ GOOGLE_UNALIGNED_LOAD64(b);
+    uint64 y = GOOGLE_UNALIGNED_LOAD64(a + 8) ^ GOOGLE_UNALIGNED_LOAD64(b + 8);
+    if ((x | y) != 0) {
+      return false;
+    }
+    a += 16;
+    b += 16;
+  }
+  // n must be 0 or 8 now because it was a multiple of 8 at the top of the loop.
+  return n == 0 || GOOGLE_UNALIGNED_LOAD64(a) == GOOGLE_UNALIGNED_LOAD64(b);
+}
+
+inline int fastmemcmp_inlined(const char *a, const char *b, size_t n) {
+  if (n >= 64) {
+    return memcmp(a, b, n);
+  }
+  const char* a_limit = a + n;
+  while (a + sizeof(uint64) <= a_limit &&
+         GOOGLE_UNALIGNED_LOAD64(a) == GOOGLE_UNALIGNED_LOAD64(b)) {
+    a += sizeof(uint64);
+    b += sizeof(uint64);
+  }
+  if (a + sizeof(uint32) <= a_limit &&
+      GOOGLE_UNALIGNED_LOAD32(a) == GOOGLE_UNALIGNED_LOAD32(b)) {
+    a += sizeof(uint32);
+    b += sizeof(uint32);
+  }
+  while (a < a_limit) {
+    int d = static_cast<uint32>(*a++) - static_cast<uint32>(*b++);
+    if (d) return d;
+  }
+  return 0;
+}
+
+// The standard memcpy operation is slow for variable small sizes.
+// This implementation inlines the optimal realization for sizes 1 to 16.
+// To avoid code bloat don't use it in case of not performance-critical spots,
+// nor when you don't expect very frequent values of size <= 16.
+inline void memcpy_inlined(char *dst, const char *src, size_t size) {
+  // Compiler inlines code with minimal amount of data movement when third
+  // parameter of memcpy is a constant.
+  switch (size) {
+    case  1: memcpy(dst, src, 1); break;
+    case  2: memcpy(dst, src, 2); break;
+    case  3: memcpy(dst, src, 3); break;
+    case  4: memcpy(dst, src, 4); break;
+    case  5: memcpy(dst, src, 5); break;
+    case  6: memcpy(dst, src, 6); break;
+    case  7: memcpy(dst, src, 7); break;
+    case  8: memcpy(dst, src, 8); break;
+    case  9: memcpy(dst, src, 9); break;
+    case 10: memcpy(dst, src, 10); break;
+    case 11: memcpy(dst, src, 11); break;
+    case 12: memcpy(dst, src, 12); break;
+    case 13: memcpy(dst, src, 13); break;
+    case 14: memcpy(dst, src, 14); break;
+    case 15: memcpy(dst, src, 15); break;
+    case 16: memcpy(dst, src, 16); break;
+    default: memcpy(dst, src, size); break;
+  }
+}
+
+}  // namespace internal
+}  // namespace protobuf
+}  // namespace google
+
+#endif  // GOOGLE_PROTOBUF_STUBS_FASTMEM_H_