Move utils.h and utils.cc from runtime/vm to runtime/platform

runtime/vm/utils.cc

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-#include "vm/utils.h"
-
-namespace dart {
-
-// Implementation is from "Hacker's Delight" by Henry S. Warren, Jr.,
-// figure 3-3, page 48, where the function is called clp2.
-uint32_t Utils::RoundUpToPowerOfTwo(uint32_t x) {
-  x = x - 1;
-  x = x | (x >> 1);
-  x = x | (x >> 2);
-  x = x | (x >> 4);
-  x = x | (x >> 8);
-  x = x | (x >> 16);
-  return x + 1;
-}
-
-
-// Implementation is from "Hacker's Delight" by Henry S. Warren, Jr.,
-// figure 5-2, page 66, where the function is called pop.
-int Utils::CountOneBits(uint32_t x) {
-  x = x - ((x >> 1) & 0x55555555);
-  x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
-  x = (x + (x >> 4)) & 0x0F0F0F0F;
-  x = x + (x >> 8);
-  x = x + (x >> 16);
-  return static_cast<int>(x & 0x0000003F);
-}
-
-
-uint32_t Utils::StringHash(const char* data, int length) {
-  // This implementation is based on the public domain MurmurHash
-  // version 2.0. It assumes that the underlying CPU can read from
-  // unaligned addresses. The constants M and R have been determined
-  // to work well experimentally.
-  // TODO(3158902): need to account for unaligned address access on ARM.
-  const uint32_t M = 0x5bd1e995;
-  const int R = 24;
-  int size = length;
-  uint32_t hash = size;
-
-  // Mix four bytes at a time into the hash.
-  const uint8_t* cursor = reinterpret_cast<const uint8_t*>(data);
-  while (size >= 4) {
-    uint32_t part = *reinterpret_cast<const uint32_t*>(cursor);
-    part *= M;
-    part ^= part >> R;
-    part *= M;
-    hash *= M;
-    hash ^= part;
-    cursor += 4;
-    size -= 4;
-  }
-
-  // Handle the last few bytes of the string.
-  switch (size) {
-    case 3:
-      hash ^= cursor[2] << 16;
-    case 2:
-      hash ^= cursor[1] << 8;
-    case 1:
-      hash ^= cursor[0];
-      hash *= M;
-  }
-
-  // Do a few final mixes of the hash to ensure the last few bytes are
-  // well-incorporated.
-  hash ^= hash >> 13;
-  hash *= M;
-  hash ^= hash >> 15;
-  return hash;
-}
-
-
-uint32_t WordHash(word key) {
-  // TODO(iposva): Need to check hash spreading.
-  // This example is from http://www.concentric.net/~Ttwang/tech/inthash.htm
-  uword a = static_cast<uword>(key);
-  a = (a + 0x7ed55d16) + (a << 12);
-  a = (a ^ 0xc761c23c) ^ (a >> 19);
-  a = (a + 0x165667b1) + (a << 5);
-  a = (a + 0xd3a2646c) ^ (a << 9);
-  a = (a + 0xfd7046c5) + (a << 3);
-  a = (a ^ 0xb55a4f09) ^ (a >> 16);
-  return static_cast<uint32_t>(a);
-}
-
-}  // namespace dart