+
+/// xorshift64star Pseudo-Random Number Generator
+/// This class is based on original code written and dedicated
+/// to the public domain by Sebastiano Vigna (2014).
+/// It has the following characteristics:
+///
+/// - Outputs 64-bit numbers
+/// - Passes Dieharder and SmallCrush test batteries
+/// - Does not require warm-up, no zeroland to escape
+/// - Internal state is a single 64-bit integer
+/// - Period is 2^64 - 1
+/// - Speed: 1.60 ns/call (Core i7 @3.40GHz)
+///
+/// For further analysis see
+/// <http://vigna.di.unimi.it/ftp/papers/xorshift.pdf>
+
+class PRNG {
+
+ uint64_t s;
+
+ uint64_t rand64() {
+
+ s ^= s >> 12, s ^= s << 25, s ^= s >> 27;
+ return s * 2685821657736338717LL;
+ }
+
+public:
+ PRNG(uint64_t seed) : s(seed) { assert(seed); }
+
+ template<typename T> T rand() { return T(rand64()); }
+
+ /// Special generator used to fast init magic numbers.
+ /// Output values only have 1/8th of their bits set on average.
+ template<typename T> T sparse_rand()
+ { return T(rand64() & rand64() & rand64()); }
+};
+
+
+/// Under Windows it is not possible for a process to run on more than one
+/// logical processor group. This usually means to be limited to use max 64
+/// cores. To overcome this, some special platform specific API should be
+/// called to set group affinity for each thread. Original code from Texel by
+/// Peter Ă–sterlund.
+
+namespace WinProcGroup {
+ void bindThisThread(size_t idx);
+}
+