Revert https://codereview.chromium.org/1291903002 (protobuf roll).

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
deleted file mode 100644
index 763a6e6024bc4b20fd566421a3b4d340a79f03d6..0000000000000000000000000000000000000000
--- a/third_party/protobuf/src/google/protobuf/stubs/fastmem.h
+++ /dev/null
@@ -1,152 +0,0 @@
-// 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_