Change the implementation of Math.random to use George...

src/v8.cc

Index: src/v8.cc
===================================================================
--- src/v8.cc	(revision 2155)
+++ src/v8.cc	(working copy)
@@ -138,4 +138,27 @@
 }
 
 
+uint32_t V8::Random() {
+  // Random number generator using George Marsaglia's
+  // multiply-with-carry algorithm.
+  static uint32_t hi = 0;
+  static uint32_t lo = 0;

[Dean McNamee, 2009/06/15 07:39:25]

why not just static uint32_t hi = random() ?

+
+  // Initialize seed using the system random().
+  if (hi == 0) hi = random();
+  if (lo == 0) lo = random();
+
+  // Mix the bits.
+  hi = 36969 * (hi & 0xFFFF) + (hi >> 16);
+  lo = 18273 * (lo & 0xFFFF) + (lo >> 16);
+  return (hi << 16) + (lo & 0xFFFF);
+}
+
+
+Smi* V8::RandomPositiveSmi() {
+  uint32_t random = Random();
+  ASSERT(IsPowerOf2(Smi::kMaxValue + 1));
+  return Smi::FromInt(random & Smi::kMaxValue);
+}
+
 } }  // namespace v8::internal