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 {
96 // Reset the running average to rational value p / q
97 void set(int64_t p, int64_t q)
98 { average = p * PERIOD * RESOLUTION / q; }
100 // Update average with value v
101 void update(int64_t v)
102 { average = RESOLUTION * v + (PERIOD - 1) * average / PERIOD; }
104 // Test if average is strictly greater than rational a / b
105 bool is_greater(int64_t a, int64_t b)
106 { return b * average > a * PERIOD * RESOLUTION ; }
109 { return average / (PERIOD * RESOLUTION); }
112 static constexpr int64_t PERIOD = 4096;
113 static constexpr int64_t RESOLUTION = 1024;
117 template <typename T, std::size_t MaxSize>
121 std::size_t size() const { return size_; }
122 void resize(std::size_t newSize) { size_ = newSize; }
123 void push_back(const T& value) { values_[size_++] = value; }
124 T& operator[](std::size_t index) { return values_[index]; }
125 T* begin() { return values_; }
126 T* end() { return values_ + size_; }
127 const T& operator[](std::size_t index) const { return values_[index]; }
128 const T* begin() const { return values_; }
129 const T* end() const { return values_ + size_; }
131 void swap(ValueList& other) {
132 const std::size_t maxSize = std::max(size_, other.size_);
133 for (std::size_t i = 0; i < maxSize; ++i) {
134 std::swap(values_[i], other.values_[i]);
136 std::swap(size_, other.size_);
141 std::size_t size_ = 0;
145 /// sigmoid(t, x0, y0, C, P, Q) implements a sigmoid-like function using only integers,
146 /// with the following properties:
148 /// - sigmoid is centered in (x0, y0)
149 /// - sigmoid has amplitude [-P/Q , P/Q] instead of [-1 , +1]
150 /// - limit is (y0 - P/Q) when t tends to -infinity
151 /// - limit is (y0 + P/Q) when t tends to +infinity
152 /// - the slope can be adjusted using C > 0, smaller C giving a steeper sigmoid
153 /// - the slope of the sigmoid when t = x0 is P/(Q*C)
154 /// - sigmoid is increasing with t when P > 0 and Q > 0
155 /// - to get a decreasing sigmoid, change sign of P
156 /// - mean value of the sigmoid is y0
158 /// Use <https://www.desmos.com/calculator/jhh83sqq92> to draw the sigmoid
160 inline int64_t sigmoid(int64_t t, int64_t x0,
168 return y0 + P * (t-x0) / (Q * (std::abs(t-x0) + C)) ;
172 /// xorshift64star Pseudo-Random Number Generator
173 /// This class is based on original code written and dedicated
174 /// to the public domain by Sebastiano Vigna (2014).
175 /// It has the following characteristics:
177 /// - Outputs 64-bit numbers
178 /// - Passes Dieharder and SmallCrush test batteries
179 /// - Does not require warm-up, no zeroland to escape
180 /// - Internal state is a single 64-bit integer
181 /// - Period is 2^64 - 1
182 /// - Speed: 1.60 ns/call (Core i7 @3.40GHz)
184 /// For further analysis see
185 /// <http://vigna.di.unimi.it/ftp/papers/xorshift.pdf>
193 s ^= s >> 12, s ^= s << 25, s ^= s >> 27;
194 return s * 2685821657736338717LL;
198 PRNG(uint64_t seed) : s(seed) { assert(seed); }
200 template<typename T> T rand() { return T(rand64()); }
202 /// Special generator used to fast init magic numbers.
203 /// Output values only have 1/8th of their bits set on average.
204 template<typename T> T sparse_rand()
205 { return T(rand64() & rand64() & rand64()); }
208 inline uint64_t mul_hi64(uint64_t a, uint64_t b) {
209 #if defined(__GNUC__) && defined(IS_64BIT)
210 __extension__ typedef unsigned __int128 uint128;
211 return ((uint128)a * (uint128)b) >> 64;
213 uint64_t aL = (uint32_t)a, aH = a >> 32;
214 uint64_t bL = (uint32_t)b, bH = b >> 32;
215 uint64_t c1 = (aL * bL) >> 32;
216 uint64_t c2 = aH * bL + c1;
217 uint64_t c3 = aL * bH + (uint32_t)c2;
218 return aH * bH + (c2 >> 32) + (c3 >> 32);
222 /// Under Windows it is not possible for a process to run on more than one
223 /// logical processor group. This usually means to be limited to use max 64
224 /// cores. To overcome this, some special platform specific API should be
225 /// called to set group affinity for each thread. Original code from Texel by
226 /// Peter Ă–sterlund.
228 namespace WinProcGroup {
229 void bindThisThread(size_t idx);
232 namespace CommandLine {
233 void init(int argc, char* argv[]);
235 extern std::string binaryDirectory; // path of the executable directory
236 extern std::string workingDirectory; // path of the working directory
239 } // namespace Stockfish
241 #endif // #ifndef MISC_H_INCLUDED