- Use the unified dart:math library in the VM.

runtime/lib/math_patch.dart

+// Copyright (c) 2012, 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.
+
+// A VM patch of the dart:math library.
+
+patch int parseInt(String str) => MathNatives.parseInt(str);
+
+patch double parseDouble(String str) => MathNatives.parseDouble(str);
+
+patch double atan2(num a, num b) => MathNatives.atan2(a, b);
+
+patch num pow(num x, num exponent) => MathNatives.pow(x, exponent);
+
+patch double sin(num x) => MathNatives.sin(x);
+patch double cos(num x) => MathNatives.cos(x);
+patch double tan(num x) => MathNatives.tan(x);
+patch double acos(num x) => MathNatives.acos(x);
+patch double asin(num x) => MathNatives.asin(x);
+patch double atan(num x) => MathNatives.atan(x);
+patch double sqrt(num x) => MathNatives.sqrt(x);
+patch double exp(num x) => MathNatives.exp(x);
+patch double log(num x) => MathNatives.log(x);
+
+
+// TODO(iposva): Handle patch methods within a patch class correctly.
+patch class Random {
+
+  /*patch*/ factory Random([int seed]) {
+    if (seed == null) {
+      seed = _Random._nextSeed();
+    }
+    do {
+      seed = (seed + 0x5A17) & _Random._MASK_64;
+    } while (seed == 0);
+    return new _Random._internal(seed);
+  }
+}
+
+
+class _Random implements Random {
+  // Internal state of the random number generator.
+  var _state;
+
+  _Random._internal(this._state);
+  
+  // The algorithm used here is Multiply with Carry (MWC) with a Base b = 2^32.
+  // http://en.wikipedia.org/wiki/Multiply-with-carry
+  // The constant A is selected from "Numerical Recipes 3rd Edition" p.348 B1.
+  int _nextInt32() {
+    _state = ((_A * (_state & _MASK_32)) + (_state >> 32)) & _MASK_64;
+    return _state & _MASK_32;
+  }
+
+  int nextInt(int max) {
+    if (max <= 0 || max > _POW2_32) {
+      throw new IllegalArgumentException("max must be positive and < 2^32:"
+                                         " $max");
+    }
+    if ((max & -max) == max) {
+      // Fast case for powers of two.
+      return _nextInt32() & (max - 1);
+    }
+
+    var rnd32;
+    var result;
+    do {
+      rnd32 = _nextInt32();
+      result = rnd32 % max;
+    } while (rnd32 - result + max >= _POW2_32);
+    return result;
+  }
+
+  double nextDouble() {
+    return ((nextInt(1 << (26)) << 27) + nextInt(1 << 27)) / _POW2_53_D;
+  }
+
+  bool nextBool() {
+    return nextInt(1) == 0;
+  }
+
+  // Constants used by the algorithm or masking.
+  static final _MASK_32 = (1 << 32) - 1;
+  static final _MASK_64 = (1 << 64) - 1;
+  static final _POW2_32 = 1 << 32;
+  static final _POW2_53_D = 1.0 * (1 << 53);
+
+  static final _A = 0xffffda61;
+
+  // Use a singleton Random object to get a new seed if no seed was passed.
+  static var _prng = null;
+
+  static int _nextSeed() {
+    if (_prng == null) {
+      // TODO(iposva): Use system to get a random seed.
+      _prng = new Random(new Date.now().millisecondsSinceEpoch);
+    }
+    // Trigger the PRNG once to change the internal state.
+    _prng._nextInt32();
+    return _prng._state;
+  }
+}