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1 | 13 | up20180614 | /* $NetBSD: bitops.h,v 1.11 2012/12/07 02:27:58 christos Exp $ */
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2 | |||
3 | /*-
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4 | * Copyright (c) 2007, 2010 The NetBSD Foundation, Inc.
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5 | * All rights reserved.
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6 | *
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7 | * This code is derived from software contributed to The NetBSD Foundation
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8 | * by Christos Zoulas and Joerg Sonnenberger.
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9 | *
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10 | * Redistribution and use in source and binary forms, with or without
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11 | * modification, are permitted provided that the following conditions
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12 | * are met:
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13 | * 1. Redistributions of source code must retain the above copyright
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14 | * notice, this list of conditions and the following disclaimer.
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15 | * 2. Redistributions in binary form must reproduce the above copyright
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16 | * notice, this list of conditions and the following disclaimer in the
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17 | * documentation and/or other materials provided with the distribution.
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18 | *
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19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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29 | * POSSIBILITY OF SUCH DAMAGE.
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30 | */
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31 | #ifndef _SYS_BITOPS_H_
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32 | #define _SYS_BITOPS_H_
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33 | |||
34 | #include <sys/stdint.h> |
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35 | |||
36 | /*
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37 | * Find First Set functions
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38 | */
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39 | #ifndef ffs32
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40 | static __inline int __unused |
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41 | ffs32(uint32_t _n) |
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42 | { |
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43 | int _v;
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44 | |||
45 | if (!_n)
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46 | return 0; |
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47 | |||
48 | _v = 1;
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49 | if ((_n & 0x0000FFFFU) == 0) { |
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50 | _n >>= 16;
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51 | _v += 16;
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52 | } |
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53 | if ((_n & 0x000000FFU) == 0) { |
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54 | _n >>= 8;
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55 | _v += 8;
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56 | } |
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57 | if ((_n & 0x0000000FU) == 0) { |
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58 | _n >>= 4;
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59 | _v += 4;
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60 | } |
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61 | if ((_n & 0x00000003U) == 0) { |
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62 | _n >>= 2;
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63 | _v += 2;
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64 | } |
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65 | if ((_n & 0x00000001U) == 0) { |
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66 | _n >>= 1;
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67 | _v += 1;
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68 | } |
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69 | return _v;
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70 | } |
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71 | #endif
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72 | |||
73 | #ifndef ffs64
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74 | static __inline int __unused |
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75 | ffs64(uint64_t _n) |
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76 | { |
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77 | int _v;
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78 | |||
79 | if (!_n)
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80 | return 0; |
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81 | |||
82 | _v = 1;
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83 | if ((_n & 0x00000000FFFFFFFFULL) == 0) { |
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84 | _n >>= 32;
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85 | _v += 32;
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86 | } |
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87 | if ((_n & 0x000000000000FFFFULL) == 0) { |
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88 | _n >>= 16;
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89 | _v += 16;
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90 | } |
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91 | if ((_n & 0x00000000000000FFULL) == 0) { |
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92 | _n >>= 8;
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93 | _v += 8;
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94 | } |
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95 | if ((_n & 0x000000000000000FULL) == 0) { |
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96 | _n >>= 4;
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97 | _v += 4;
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98 | } |
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99 | if ((_n & 0x0000000000000003ULL) == 0) { |
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100 | _n >>= 2;
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101 | _v += 2;
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102 | } |
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103 | if ((_n & 0x0000000000000001ULL) == 0) { |
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104 | _n >>= 1;
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105 | _v += 1;
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106 | } |
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107 | return _v;
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108 | } |
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109 | #endif
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110 | |||
111 | /*
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112 | * Find Last Set functions
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113 | */
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114 | #ifndef fls32
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115 | static __inline int __unused |
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116 | fls32(uint32_t _n) |
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117 | { |
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118 | int _v;
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119 | |||
120 | if (!_n)
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121 | return 0; |
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122 | |||
123 | _v = 32;
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124 | if ((_n & 0xFFFF0000U) == 0) { |
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125 | _n <<= 16;
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126 | _v -= 16;
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127 | } |
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128 | if ((_n & 0xFF000000U) == 0) { |
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129 | _n <<= 8;
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130 | _v -= 8;
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131 | } |
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132 | if ((_n & 0xF0000000U) == 0) { |
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133 | _n <<= 4;
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134 | _v -= 4;
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135 | } |
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136 | if ((_n & 0xC0000000U) == 0) { |
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137 | _n <<= 2;
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138 | _v -= 2;
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139 | } |
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140 | if ((_n & 0x80000000U) == 0) { |
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141 | _n <<= 1;
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142 | _v -= 1;
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143 | } |
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144 | return _v;
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145 | } |
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146 | #endif
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147 | |||
148 | #ifndef fls64
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149 | static __inline int __unused |
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150 | fls64(uint64_t _n) |
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151 | { |
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152 | int _v;
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153 | |||
154 | if (!_n)
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155 | return 0; |
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156 | |||
157 | _v = 64;
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158 | if ((_n & 0xFFFFFFFF00000000ULL) == 0) { |
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159 | _n <<= 32;
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160 | _v -= 32;
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161 | } |
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162 | if ((_n & 0xFFFF000000000000ULL) == 0) { |
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163 | _n <<= 16;
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164 | _v -= 16;
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165 | } |
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166 | if ((_n & 0xFF00000000000000ULL) == 0) { |
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167 | _n <<= 8;
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168 | _v -= 8;
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169 | } |
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170 | if ((_n & 0xF000000000000000ULL) == 0) { |
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171 | _n <<= 4;
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172 | _v -= 4;
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173 | } |
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174 | if ((_n & 0xC000000000000000ULL) == 0) { |
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175 | _n <<= 2;
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176 | _v -= 2;
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177 | } |
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178 | if ((_n & 0x8000000000000000ULL) == 0) { |
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179 | _n <<= 1;
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180 | _v -= 1;
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181 | } |
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182 | return _v;
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183 | } |
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184 | #endif
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185 | |||
186 | /*
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187 | * Integer logarithm, returns -1 on error. Inspired by the linux
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188 | * version written by David Howells.
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189 | */
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190 | #define _ilog2_helper(_n, _x) ((_n) & (1ULL << (_x))) ? _x : |
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191 | #define _ilog2_const(_n) ( \
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192 | _ilog2_helper(_n, 63) \
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193 | _ilog2_helper(_n, 62) \
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194 | _ilog2_helper(_n, 61) \
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195 | _ilog2_helper(_n, 60) \
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196 | _ilog2_helper(_n, 59) \
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197 | _ilog2_helper(_n, 58) \
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198 | _ilog2_helper(_n, 57) \
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199 | _ilog2_helper(_n, 56) \
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200 | _ilog2_helper(_n, 55) \
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201 | _ilog2_helper(_n, 54) \
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202 | _ilog2_helper(_n, 53) \
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203 | _ilog2_helper(_n, 52) \
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204 | _ilog2_helper(_n, 51) \
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205 | _ilog2_helper(_n, 50) \
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206 | _ilog2_helper(_n, 49) \
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207 | _ilog2_helper(_n, 48) \
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208 | _ilog2_helper(_n, 47) \
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209 | _ilog2_helper(_n, 46) \
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210 | _ilog2_helper(_n, 45) \
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211 | _ilog2_helper(_n, 44) \
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212 | _ilog2_helper(_n, 43) \
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213 | _ilog2_helper(_n, 42) \
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214 | _ilog2_helper(_n, 41) \
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215 | _ilog2_helper(_n, 40) \
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216 | _ilog2_helper(_n, 39) \
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217 | _ilog2_helper(_n, 38) \
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218 | _ilog2_helper(_n, 37) \
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219 | _ilog2_helper(_n, 36) \
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220 | _ilog2_helper(_n, 35) \
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221 | _ilog2_helper(_n, 34) \
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222 | _ilog2_helper(_n, 33) \
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223 | _ilog2_helper(_n, 32) \
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224 | _ilog2_helper(_n, 31) \
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225 | _ilog2_helper(_n, 30) \
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226 | _ilog2_helper(_n, 29) \
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227 | _ilog2_helper(_n, 28) \
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228 | _ilog2_helper(_n, 27) \
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229 | _ilog2_helper(_n, 26) \
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230 | _ilog2_helper(_n, 25) \
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231 | _ilog2_helper(_n, 24) \
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232 | _ilog2_helper(_n, 23) \
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233 | _ilog2_helper(_n, 22) \
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234 | _ilog2_helper(_n, 21) \
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235 | _ilog2_helper(_n, 20) \
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236 | _ilog2_helper(_n, 19) \
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237 | _ilog2_helper(_n, 18) \
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238 | _ilog2_helper(_n, 17) \
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239 | _ilog2_helper(_n, 16) \
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240 | _ilog2_helper(_n, 15) \
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241 | _ilog2_helper(_n, 14) \
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242 | _ilog2_helper(_n, 13) \
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243 | _ilog2_helper(_n, 12) \
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244 | _ilog2_helper(_n, 11) \
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245 | _ilog2_helper(_n, 10) \
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246 | _ilog2_helper(_n, 9) \
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247 | _ilog2_helper(_n, 8) \
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248 | _ilog2_helper(_n, 7) \
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249 | _ilog2_helper(_n, 6) \
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250 | _ilog2_helper(_n, 5) \
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251 | _ilog2_helper(_n, 4) \
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252 | _ilog2_helper(_n, 3) \
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253 | _ilog2_helper(_n, 2) \
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254 | _ilog2_helper(_n, 1) \
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255 | _ilog2_helper(_n, 0) \
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256 | -1)
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257 | |||
258 | #define ilog2(_n) \
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259 | ( \ |
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260 | __builtin_constant_p(_n) ? _ilog2_const(_n) : \ |
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261 | ((sizeof(_n) > 4 ? fls64(_n) : fls32(_n)) - 1) \ |
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262 | ) |
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263 | |||
264 | static __inline void |
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265 | fast_divide32_prepare(uint32_t _div, uint32_t * __restrict _m, |
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266 | uint8_t *__restrict _s1, uint8_t *__restrict _s2) |
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267 | { |
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268 | uint64_t _mt; |
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269 | int _l;
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270 | |||
271 | _l = fls32(_div - 1);
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272 | _mt = (uint64_t)(0x100000000ULL * ((1ULL << _l) - _div)); |
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273 | *_m = (uint32_t)(_mt / _div + 1);
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274 | *_s1 = (_l > 1) ? 1 : _l; |
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275 | *_s2 = (_l == 0) ? 0 : _l - 1; |
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276 | } |
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277 | |||
278 | /* ARGSUSED */
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279 | static __inline uint32_t
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280 | fast_divide32(uint32_t _v, uint32_t _div __unused, uint32_t _m, uint8_t _s1, |
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281 | uint8_t _s2) |
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282 | { |
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283 | uint32_t _t; |
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284 | |||
285 | _t = (uint32_t)(((uint64_t)_v * _m) >> 32);
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286 | return (_t + ((_v - _t) >> _s1)) >> _s2;
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287 | } |
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288 | |||
289 | static __inline uint32_t
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290 | fast_remainder32(uint32_t _v, uint32_t _div, uint32_t _m, uint8_t _s1, |
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291 | uint8_t _s2) |
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292 | { |
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293 | |||
294 | return _v - _div * fast_divide32(_v, _div, _m, _s1, _s2);
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295 | } |
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296 | |||
297 | #define __BITMAP_TYPE(__s, __t, __n) struct __s { \ |
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298 | __t _b[__BITMAP_SIZE(__t, __n)]; \ |
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299 | } |
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300 | |||
301 | #define __BITMAP_BITS(__t) (sizeof(__t) * NBBY) |
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302 | #define __BITMAP_SHIFT(__t) (ilog2(__BITMAP_BITS(__t)))
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303 | #define __BITMAP_MASK(__t) (__BITMAP_BITS(__t) - 1) |
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304 | #define __BITMAP_SIZE(__t, __n) \
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305 | (((__n) + (__BITMAP_BITS(__t) - 1)) / __BITMAP_BITS(__t))
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306 | #define __BITMAP_BIT(__n, __v) \
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307 | (1 << ((__n) & __BITMAP_MASK(*(__v)->_b)))
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308 | #define __BITMAP_WORD(__n, __v) \
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309 | ((__n) >> __BITMAP_SHIFT(*(__v)->_b)) |
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310 | |||
311 | #define __BITMAP_SET(__n, __v) \
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312 | ((__v)->_b[__BITMAP_WORD(__n, __v)] |= __BITMAP_BIT(__n, __v)) |
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313 | #define __BITMAP_CLR(__n, __v) \
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314 | ((__v)->_b[__BITMAP_WORD(__n, __v)] &= ~__BITMAP_BIT(__n, __v)) |
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315 | #define __BITMAP_ISSET(__n, __v) \
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316 | ((__v)->_b[__BITMAP_WORD(__n, __v)] & __BITMAP_BIT(__n, __v)) |
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317 | |||
318 | #if __GNUC_PREREQ__(2, 95) |
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319 | #define __BITMAP_ZERO(__v) \
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320 | (void)__builtin_memset((__v), 0, sizeof(*__v)) |
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321 | #else
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322 | #define __BITMAP_ZERO(__v) do { \ |
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323 | size_t __i; \ |
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324 | for (__i = 0; __i < __arraycount(__v->_b); __i++) \ |
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325 | (__v)->_b[__i] = 0; \
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326 | } while (/* CONSTCOND */ 0) |
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327 | #endif /* GCC 2.95 */ |
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328 | |||
329 | #endif /* _SYS_BITOPS_H_ */ |