2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2022 The Stockfish developers (see AUTHORS file)
5 Stockfish is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 Stockfish is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
19 #ifndef MISC_H_INCLUDED
20 #define MISC_H_INCLUDED
33 std::string engine_info(bool to_uci = false);
34 std::string compiler_info();
35 void prefetch(void* addr);
36 void start_logger(const std::string& fname);
37 void* std_aligned_alloc(size_t alignment, size_t size);
38 void std_aligned_free(void* ptr);
39 void* aligned_large_pages_alloc(size_t size); // memory aligned by page size, min alignment: 4096 bytes
40 void aligned_large_pages_free(void* mem); // nop if mem == nullptr
42 void dbg_hit_on(bool b);
43 void dbg_hit_on(bool c, bool b);
44 void dbg_mean_of(int v);
47 typedef std::chrono::milliseconds::rep TimePoint; // A value in milliseconds
48 static_assert(sizeof(TimePoint) == sizeof(int64_t), "TimePoint should be 64 bits");
49 inline TimePoint now() {
50 return std::chrono::duration_cast<std::chrono::milliseconds>
51 (std::chrono::steady_clock::now().time_since_epoch()).count();
54 template<class Entry, int Size>
56 Entry* operator[](Key key) { return &table[(uint32_t)key & (Size - 1)]; }
59 std::vector<Entry> table = std::vector<Entry>(Size); // Allocate on the heap
63 enum SyncCout { IO_LOCK, IO_UNLOCK };
64 std::ostream& operator<<(std::ostream&, SyncCout);
66 #define sync_cout std::cout << IO_LOCK
67 #define sync_endl std::endl << IO_UNLOCK
70 // align_ptr_up() : get the first aligned element of an array.
71 // ptr must point to an array of size at least `sizeof(T) * N + alignment` bytes,
72 // where N is the number of elements in the array.
73 template <uintptr_t Alignment, typename T>
74 T* align_ptr_up(T* ptr)
76 static_assert(alignof(T) < Alignment);
78 const uintptr_t ptrint = reinterpret_cast<uintptr_t>(reinterpret_cast<char*>(ptr));
79 return reinterpret_cast<T*>(reinterpret_cast<char*>((ptrint + (Alignment - 1)) / Alignment * Alignment));
83 // IsLittleEndian : true if and only if the binary is compiled on a little endian machine
84 static inline const union { uint32_t i; char c[4]; } Le = { 0x01020304 };
85 static inline const bool IsLittleEndian = (Le.c[0] == 4);
88 // RunningAverage : a class to calculate a running average of a series of values.
89 // For efficiency, all computations are done with integers.
90 class RunningAverage {
93 // Reset the running average to rational value p / q
94 void set(int64_t p, int64_t q)
95 { average = p * PERIOD * RESOLUTION / q; }
97 // Update average with value v
98 void update(int64_t v)
99 { average = RESOLUTION * v + (PERIOD - 1) * average / PERIOD; }
101 // Test if average is strictly greater than rational a / b
102 bool is_greater(int64_t a, int64_t b) const
103 { return b * average > a * (PERIOD * RESOLUTION); }
105 int64_t value() const
106 { return average / (PERIOD * RESOLUTION); }
109 static constexpr int64_t PERIOD = 4096;
110 static constexpr int64_t RESOLUTION = 1024;
114 template <typename T, std::size_t MaxSize>
118 std::size_t size() const { return size_; }
119 void push_back(const T& value) { values_[size_++] = value; }
120 const T* begin() const { return values_; }
121 const T* end() const { return values_ + size_; }
125 std::size_t size_ = 0;
129 /// sigmoid(t, x0, y0, C, P, Q) implements a sigmoid-like function using only integers,
130 /// with the following properties:
132 /// - sigmoid is centered in (x0, y0)
133 /// - sigmoid has amplitude [-P/Q , P/Q] instead of [-1 , +1]
134 /// - limit is (y0 - P/Q) when t tends to -infinity
135 /// - limit is (y0 + P/Q) when t tends to +infinity
136 /// - the slope can be adjusted using C > 0, smaller C giving a steeper sigmoid
137 /// - the slope of the sigmoid when t = x0 is P/(Q*C)
138 /// - sigmoid is increasing with t when P > 0 and Q > 0
139 /// - to get a decreasing sigmoid, change sign of P
140 /// - mean value of the sigmoid is y0
142 /// Use <https://www.desmos.com/calculator/jhh83sqq92> to draw the sigmoid
144 inline int64_t sigmoid(int64_t t, int64_t x0,
152 return y0 + P * (t-x0) / (Q * (std::abs(t-x0) + C)) ;
156 /// xorshift64star Pseudo-Random Number Generator
157 /// This class is based on original code written and dedicated
158 /// to the public domain by Sebastiano Vigna (2014).
159 /// It has the following characteristics:
161 /// - Outputs 64-bit numbers
162 /// - Passes Dieharder and SmallCrush test batteries
163 /// - Does not require warm-up, no zeroland to escape
164 /// - Internal state is a single 64-bit integer
165 /// - Period is 2^64 - 1
166 /// - Speed: 1.60 ns/call (Core i7 @3.40GHz)
168 /// For further analysis see
169 /// <http://vigna.di.unimi.it/ftp/papers/xorshift.pdf>
177 s ^= s >> 12, s ^= s << 25, s ^= s >> 27;
178 return s * 2685821657736338717LL;
182 PRNG(uint64_t seed) : s(seed) { assert(seed); }
184 template<typename T> T rand() { return T(rand64()); }
186 /// Special generator used to fast init magic numbers.
187 /// Output values only have 1/8th of their bits set on average.
188 template<typename T> T sparse_rand()
189 { return T(rand64() & rand64() & rand64()); }
192 inline uint64_t mul_hi64(uint64_t a, uint64_t b) {
193 #if defined(__GNUC__) && defined(IS_64BIT)
194 __extension__ typedef unsigned __int128 uint128;
195 return ((uint128)a * (uint128)b) >> 64;
197 uint64_t aL = (uint32_t)a, aH = a >> 32;
198 uint64_t bL = (uint32_t)b, bH = b >> 32;
199 uint64_t c1 = (aL * bL) >> 32;
200 uint64_t c2 = aH * bL + c1;
201 uint64_t c3 = aL * bH + (uint32_t)c2;
202 return aH * bH + (c2 >> 32) + (c3 >> 32);
206 /// Under Windows it is not possible for a process to run on more than one
207 /// logical processor group. This usually means to be limited to use max 64
208 /// cores. To overcome this, some special platform specific API should be
209 /// called to set group affinity for each thread. Original code from Texel by
210 /// Peter Ă–sterlund.
212 namespace WinProcGroup {
213 void bindThisThread(size_t idx);
216 namespace CommandLine {
217 void init(int argc, char* argv[]);
219 extern std::string binaryDirectory; // path of the executable directory
220 extern std::string workingDirectory; // path of the working directory
223 } // namespace Stockfish
225 #endif // #ifndef MISC_H_INCLUDED