+// 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());
+ }
+};
+
+inline uint64_t mul_hi64(uint64_t a, uint64_t b) {
+#if defined(__GNUC__) && defined(IS_64BIT)
+ __extension__ using uint128 = unsigned __int128;
+ return (uint128(a) * uint128(b)) >> 64;
+#else
+ uint64_t aL = uint32_t(a), aH = a >> 32;
+ uint64_t bL = uint32_t(b), bH = b >> 32;
+ uint64_t c1 = (aL * bL) >> 32;
+ uint64_t c2 = aH * bL + c1;
+ uint64_t c3 = aL * bH + uint32_t(c2);
+ return aH * bH + (c2 >> 32) + (c3 >> 32);
+#endif
+}
+
+// Under Windows it is not possible for a process to run on more than one
+// logical processor group. This usually means being limited to using 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);
+}
+
+namespace CommandLine {
+void init(int argc, char* argv[]);
+
+extern std::string binaryDirectory; // path of the executable directory
+extern std::string workingDirectory; // path of the working directory
+}