1 | #pragma once |
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2 | |
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3 | #include <cassert> |
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4 | #include <cstddef> |
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5 | #include <atomic> |
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6 | #include <chrono> |
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7 | #include <fstream> |
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8 | #include <iostream> |
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9 | |
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10 | #include <unistd.h> |
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11 | #include <sys/sysinfo.h> |
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12 | |
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13 | #include <x86intrin.h> |
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14 | |
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15 | // Barrier from |
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16 | class barrier_t { |
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17 | public: |
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18 | barrier_t(size_t total) |
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19 | : waiting(0) |
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20 | , total(total) |
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21 | {} |
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22 | |
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23 | void wait(unsigned) { |
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24 | size_t target = waiting++; |
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25 | target = (target - (target % total)) + total; |
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26 | while(waiting < target) |
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27 | asm volatile("pause"); |
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28 | |
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29 | assert(waiting < (1ul << 60)); |
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30 | } |
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31 | |
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32 | private: |
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33 | std::atomic<size_t> waiting; |
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34 | size_t total; |
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35 | }; |
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36 | |
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37 | class Random { |
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38 | private: |
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39 | unsigned int seed; |
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40 | public: |
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41 | Random(int seed) { |
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42 | this->seed = seed; |
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43 | } |
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44 | |
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45 | /** returns pseudorandom x satisfying 0 <= x < n. **/ |
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46 | unsigned int next() { |
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47 | seed ^= seed << 6; |
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48 | seed ^= seed >> 21; |
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49 | seed ^= seed << 7; |
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50 | return seed; |
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51 | } |
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52 | }; |
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53 | |
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54 | static inline long long rdtscl(void) { |
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55 | unsigned int lo, hi; |
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56 | __asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi)); |
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57 | return ( (unsigned long long)lo)|( ((unsigned long long)hi)<<32 ); |
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58 | } |
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59 | |
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60 | void affinity(int tid) { |
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61 | static int cpus = get_nprocs(); |
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62 | |
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63 | cpu_set_t mask; |
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64 | CPU_ZERO(&mask); |
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65 | int cpu = cpus - tid; // Set CPU affinity to tid, starting from the end |
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66 | CPU_SET(cpu, &mask); |
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67 | auto result = sched_setaffinity(0, sizeof(mask), &mask); |
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68 | if(result != 0) { |
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69 | std::cerr << "Affinity set failed with " << result<< ", wanted " << cpu << std::endl; |
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70 | } |
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71 | } |
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72 | |
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73 | static const constexpr std::size_t cache_line_size = 64; |
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74 | void check_cache_line_size() { |
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75 | std::cout << "Checking cache line size" << std::endl; |
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76 | const std::string cache_file = "/sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size"; |
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77 | |
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78 | std::ifstream ifs (cache_file, std::ifstream::in); |
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79 | |
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80 | if(!ifs.good()) { |
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81 | std::cerr << "Could not open file to check cache line size" << std::endl; |
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82 | std::cerr << "Looking for: " << cache_file << std::endl; |
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83 | std::exit(2); |
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84 | } |
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85 | |
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86 | size_t got; |
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87 | ifs >> got; |
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88 | |
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89 | ifs.close(); |
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90 | |
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91 | if(cache_line_size != got) { |
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92 | std::cerr << "Cache line has incorrect size : " << got << std::endl; |
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93 | std::exit(1); |
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94 | } |
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95 | |
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96 | std::cout << "Done" << std::endl; |
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97 | } |
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98 | |
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99 | using Clock = std::chrono::high_resolution_clock; |
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100 | using duration_t = std::chrono::duration<double>; |
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101 | using std::chrono::nanoseconds; |
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102 | |
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103 | template<typename Ratio, typename T> |
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104 | T duration_cast(T seconds) { |
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105 | return std::chrono::duration_cast<std::chrono::duration<T, Ratio>>(std::chrono::duration<T>(seconds)).count(); |
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106 | } |
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107 | |
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108 | // from geeksforgeeks |
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109 | const constexpr unsigned num_to_bits[16] = {0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4}; |
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110 | |
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111 | /* Recursively get nibble of a given number |
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112 | and map them in the array */ |
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113 | __attribute__((noinline)) unsigned countSetBits(size_t num) { |
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114 | unsigned nibble = 0; |
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115 | if (0 == num) |
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116 | return num_to_bits[0]; |
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117 | |
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118 | // Find last nibble |
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119 | nibble = num & 0xf; |
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120 | |
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121 | // Use pre-stored values to find count |
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122 | // in last nibble plus recursively add |
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123 | // remaining nibbles. |
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124 | return num_to_bits[nibble] + countSetBits(num >> 4); |
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125 | } |
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126 | |
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127 | __attribute__((noinline)) unsigned nthSetBit(size_t mask, unsigned bit) { |
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128 | uint64_t v = mask; // Input value to find position with rank r. |
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129 | unsigned int r = bit;// Input: bit's desired rank [1-64]. |
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130 | unsigned int s; // Output: Resulting position of bit with rank r [1-64] |
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131 | uint64_t a, b, c, d; // Intermediate temporaries for bit count. |
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132 | unsigned int t; // Bit count temporary. |
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133 | |
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134 | // Do a normal parallel bit count for a 64-bit integer, |
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135 | // but store all intermediate steps. |
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136 | // a = (v & 0x5555...) + ((v >> 1) & 0x5555...); |
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137 | a = v - ((v >> 1) & ~0UL/3); |
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138 | // b = (a & 0x3333...) + ((a >> 2) & 0x3333...); |
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139 | b = (a & ~0UL/5) + ((a >> 2) & ~0UL/5); |
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140 | // c = (b & 0x0f0f...) + ((b >> 4) & 0x0f0f...); |
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141 | c = (b + (b >> 4)) & ~0UL/0x11; |
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142 | // d = (c & 0x00ff...) + ((c >> 8) & 0x00ff...); |
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143 | d = (c + (c >> 8)) & ~0UL/0x101; |
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144 | |
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145 | |
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146 | t = (d >> 32) + (d >> 48); |
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147 | // Now do branchless select! |
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148 | s = 64; |
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149 | // if (r > t) {s -= 32; r -= t;} |
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150 | s -= ((t - r) & 256) >> 3; r -= (t & ((t - r) >> 8)); |
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151 | t = (d >> (s - 16)) & 0xff; |
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152 | // if (r > t) {s -= 16; r -= t;} |
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153 | s -= ((t - r) & 256) >> 4; r -= (t & ((t - r) >> 8)); |
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154 | t = (c >> (s - 8)) & 0xf; |
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155 | // if (r > t) {s -= 8; r -= t;} |
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156 | s -= ((t - r) & 256) >> 5; r -= (t & ((t - r) >> 8)); |
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157 | t = (b >> (s - 4)) & 0x7; |
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158 | // if (r > t) {s -= 4; r -= t;} |
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159 | s -= ((t - r) & 256) >> 6; r -= (t & ((t - r) >> 8)); |
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160 | t = (a >> (s - 2)) & 0x3; |
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161 | // if (r > t) {s -= 2; r -= t;} |
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162 | s -= ((t - r) & 256) >> 7; r -= (t & ((t - r) >> 8)); |
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163 | t = (v >> (s - 1)) & 0x1; |
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164 | // if (r > t) s--; |
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165 | s -= ((t - r) & 256) >> 8; |
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166 | s = 65 - s; |
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167 | return s; |
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168 | } |
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169 | |
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170 | // __attribute__((noinline)) unsigned int nth_bit_set(uint64_t value, unsigned int n) |
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171 | // { |
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172 | // uint64_t mask = 0x00000000FFFFFFFFul; |
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173 | // unsigned int size = 32u; |
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174 | // unsigned int base = 0u; |
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175 | |
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176 | // if(value == 0) return 0; |
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177 | // assertf(n < (unsigned)__builtin_popcountl(value), "%u < %d (%zu)", n, __builtin_popcountl(value), value); |
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178 | // n++; |
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179 | // while (size > 0) { |
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180 | // const unsigned int count = __builtin_popcountl(value & mask); |
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181 | // if (n > count) { |
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182 | // base += size; |
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183 | // size >>= 1; |
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184 | // mask |= mask << size; |
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185 | // } else { |
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186 | // size >>= 1; |
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187 | // mask >>= size; |
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188 | // } |
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189 | // } |
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190 | |
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191 | // return base; |
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192 | // } |
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193 | |
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194 | |
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195 | static inline uint64_t rotl64 (uint64_t n, unsigned int c) { |
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196 | const unsigned int mask = (8*sizeof(n) - 1); // assumes width is a power of 2. |
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197 | |
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198 | c &= mask; |
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199 | return (n<<c) | (n>>( (-c)&mask )); |
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200 | } |
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201 | |
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202 | static inline uint64_t rotr64 (uint64_t n, unsigned int c) |
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203 | { |
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204 | const unsigned int mask = (8*sizeof(n) - 1); |
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205 | |
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206 | // assert ( (c<=mask) &&"rotate by type width or more"); |
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207 | c &= mask; |
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208 | return (n>>c) | (n<<( (-c)&mask )); |
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209 | } |
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