1 | /*
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2 | * bzip2 is written by Julian Seward <jseward@bzip.org>.
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3 | * Adapted for busybox by Denys Vlasenko <vda.linux@googlemail.com>.
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4 | * See README and LICENSE files in this directory for more information.
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5 | */
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6 |
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7 | /*-------------------------------------------------------------*/
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8 | /*--- Block sorting machinery ---*/
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9 | /*--- blocksort.c ---*/
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10 | /*-------------------------------------------------------------*/
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11 |
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12 | /* ------------------------------------------------------------------
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13 | This file is part of bzip2/libbzip2, a program and library for
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14 | lossless, block-sorting data compression.
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15 |
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16 | bzip2/libbzip2 version 1.0.4 of 20 December 2006
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17 | Copyright (C) 1996-2006 Julian Seward <jseward@bzip.org>
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18 |
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19 | Please read the WARNING, DISCLAIMER and PATENTS sections in the
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20 | README file.
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21 |
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22 | This program is released under the terms of the license contained
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23 | in the file LICENSE.
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24 | ------------------------------------------------------------------ */
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25 |
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26 | /* #include "bzlib_private.h" */
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27 |
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28 | #define mswap(zz1, zz2) \
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29 | { \
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30 | int32_t zztmp = zz1; \
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31 | zz1 = zz2; \
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32 | zz2 = zztmp; \
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33 | }
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34 |
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35 | static
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36 | /* No measurable speed gain with inlining */
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37 | /* ALWAYS_INLINE */
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38 | void mvswap(uint32_t* ptr, int32_t zzp1, int32_t zzp2, int32_t zzn)
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39 | {
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40 | while (zzn > 0) {
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41 | mswap(ptr[zzp1], ptr[zzp2]);
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42 | zzp1++;
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43 | zzp2++;
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44 | zzn--;
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45 | }
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46 | }
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47 |
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48 | static
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49 | ALWAYS_INLINE
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50 | int32_t mmin(int32_t a, int32_t b)
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51 | {
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52 | return (a < b) ? a : b;
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53 | }
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54 |
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55 |
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56 | /*---------------------------------------------*/
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57 | /*--- Fallback O(N log(N)^2) sorting ---*/
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58 | /*--- algorithm, for repetitive blocks ---*/
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59 | /*---------------------------------------------*/
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60 |
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61 | /*---------------------------------------------*/
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62 | static
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63 | inline
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64 | void fallbackSimpleSort(uint32_t* fmap,
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65 | uint32_t* eclass,
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66 | int32_t lo,
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67 | int32_t hi)
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68 | {
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69 | int32_t i, j, tmp;
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70 | uint32_t ec_tmp;
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71 |
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72 | if (lo == hi) return;
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73 |
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74 | if (hi - lo > 3) {
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75 | for (i = hi-4; i >= lo; i--) {
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76 | tmp = fmap[i];
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77 | ec_tmp = eclass[tmp];
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78 | for (j = i+4; j <= hi && ec_tmp > eclass[fmap[j]]; j += 4)
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79 | fmap[j-4] = fmap[j];
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80 | fmap[j-4] = tmp;
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81 | }
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82 | }
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83 |
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84 | for (i = hi-1; i >= lo; i--) {
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85 | tmp = fmap[i];
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86 | ec_tmp = eclass[tmp];
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87 | for (j = i+1; j <= hi && ec_tmp > eclass[fmap[j]]; j++)
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88 | fmap[j-1] = fmap[j];
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89 | fmap[j-1] = tmp;
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90 | }
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91 | }
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92 |
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93 |
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94 | /*---------------------------------------------*/
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95 | #define fpush(lz,hz) { \
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96 | stackLo[sp] = lz; \
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97 | stackHi[sp] = hz; \
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98 | sp++; \
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99 | }
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100 |
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101 | #define fpop(lz,hz) { \
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102 | sp--; \
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103 | lz = stackLo[sp]; \
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104 | hz = stackHi[sp]; \
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105 | }
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106 |
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107 | #define FALLBACK_QSORT_SMALL_THRESH 10
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108 | #define FALLBACK_QSORT_STACK_SIZE 100
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109 |
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110 | static
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111 | void fallbackQSort3(uint32_t* fmap,
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112 | uint32_t* eclass,
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113 | int32_t loSt,
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114 | int32_t hiSt)
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115 | {
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116 | int32_t unLo, unHi, ltLo, gtHi, n, m;
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117 | int32_t sp, lo, hi;
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118 | uint32_t med, r, r3;
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119 | int32_t stackLo[FALLBACK_QSORT_STACK_SIZE];
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120 | int32_t stackHi[FALLBACK_QSORT_STACK_SIZE];
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121 |
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122 | r = 0;
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123 |
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124 | sp = 0;
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125 | fpush(loSt, hiSt);
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126 |
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127 | while (sp > 0) {
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128 | AssertH(sp < FALLBACK_QSORT_STACK_SIZE - 1, 1004);
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129 |
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130 | fpop(lo, hi);
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131 | if (hi - lo < FALLBACK_QSORT_SMALL_THRESH) {
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132 | fallbackSimpleSort(fmap, eclass, lo, hi);
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133 | continue;
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134 | }
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135 |
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136 | /* Random partitioning. Median of 3 sometimes fails to
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137 | * avoid bad cases. Median of 9 seems to help but
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138 | * looks rather expensive. This too seems to work but
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139 | * is cheaper. Guidance for the magic constants
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140 | * 7621 and 32768 is taken from Sedgewick's algorithms
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141 | * book, chapter 35.
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142 | */
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143 | r = ((r * 7621) + 1) % 32768;
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144 | r3 = r % 3;
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145 | if (r3 == 0)
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146 | med = eclass[fmap[lo]];
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147 | else if (r3 == 1)
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148 | med = eclass[fmap[(lo+hi)>>1]];
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149 | else
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150 | med = eclass[fmap[hi]];
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151 |
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152 | unLo = ltLo = lo;
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153 | unHi = gtHi = hi;
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154 |
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155 | while (1) {
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156 | while (1) {
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157 | if (unLo > unHi) break;
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158 | n = (int32_t)eclass[fmap[unLo]] - (int32_t)med;
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159 | if (n == 0) {
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160 | mswap(fmap[unLo], fmap[ltLo]);
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161 | ltLo++;
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162 | unLo++;
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163 | continue;
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164 | };
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165 | if (n > 0) break;
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166 | unLo++;
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167 | }
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168 | while (1) {
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169 | if (unLo > unHi) break;
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170 | n = (int32_t)eclass[fmap[unHi]] - (int32_t)med;
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171 | if (n == 0) {
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172 | mswap(fmap[unHi], fmap[gtHi]);
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173 | gtHi--; unHi--;
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174 | continue;
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175 | };
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176 | if (n < 0) break;
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177 | unHi--;
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178 | }
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179 | if (unLo > unHi) break;
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180 | mswap(fmap[unLo], fmap[unHi]); unLo++; unHi--;
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181 | }
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182 |
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183 | AssertD(unHi == unLo-1, "fallbackQSort3(2)");
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184 |
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185 | if (gtHi < ltLo) continue;
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186 |
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187 | n = mmin(ltLo-lo, unLo-ltLo); mvswap(fmap, lo, unLo-n, n);
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188 | m = mmin(hi-gtHi, gtHi-unHi); mvswap(fmap, unLo, hi-m+1, m);
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189 |
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190 | n = lo + unLo - ltLo - 1;
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191 | m = hi - (gtHi - unHi) + 1;
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192 |
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193 | if (n - lo > hi - m) {
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194 | fpush(lo, n);
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195 | fpush(m, hi);
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196 | } else {
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197 | fpush(m, hi);
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198 | fpush(lo, n);
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199 | }
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200 | }
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201 | }
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202 |
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203 | #undef fpush
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204 | #undef fpop
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205 | #undef FALLBACK_QSORT_SMALL_THRESH
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206 | #undef FALLBACK_QSORT_STACK_SIZE
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207 |
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208 |
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209 | /*---------------------------------------------*/
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210 | /* Pre:
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211 | * nblock > 0
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212 | * eclass exists for [0 .. nblock-1]
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213 | * ((uint8_t*)eclass) [0 .. nblock-1] holds block
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214 | * ptr exists for [0 .. nblock-1]
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215 | *
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216 | * Post:
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217 | * ((uint8_t*)eclass) [0 .. nblock-1] holds block
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218 | * All other areas of eclass destroyed
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219 | * fmap [0 .. nblock-1] holds sorted order
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220 | * bhtab[0 .. 2+(nblock/32)] destroyed
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221 | */
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222 |
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223 | #define SET_BH(zz) bhtab[(zz) >> 5] |= (1 << ((zz) & 31))
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224 | #define CLEAR_BH(zz) bhtab[(zz) >> 5] &= ~(1 << ((zz) & 31))
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225 | #define ISSET_BH(zz) (bhtab[(zz) >> 5] & (1 << ((zz) & 31)))
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226 | #define WORD_BH(zz) bhtab[(zz) >> 5]
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227 | #define UNALIGNED_BH(zz) ((zz) & 0x01f)
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228 |
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229 | static
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230 | void fallbackSort(uint32_t* fmap,
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231 | uint32_t* eclass,
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232 | uint32_t* bhtab,
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233 | int32_t nblock)
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234 | {
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235 | int32_t ftab[257];
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236 | int32_t ftabCopy[256];
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237 | int32_t H, i, j, k, l, r, cc, cc1;
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238 | int32_t nNotDone;
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239 | int32_t nBhtab;
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240 | uint8_t* eclass8 = (uint8_t*)eclass;
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241 |
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242 | /*
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243 | * Initial 1-char radix sort to generate
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244 | * initial fmap and initial BH bits.
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245 | */
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246 | for (i = 0; i < 257; i++) ftab[i] = 0;
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247 | for (i = 0; i < nblock; i++) ftab[eclass8[i]]++;
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248 | for (i = 0; i < 256; i++) ftabCopy[i] = ftab[i];
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249 |
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250 | j = ftab[0]; /* bbox: optimized */
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251 | for (i = 1; i < 257; i++) {
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252 | j += ftab[i];
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253 | ftab[i] = j;
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254 | }
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255 |
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256 | for (i = 0; i < nblock; i++) {
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257 | j = eclass8[i];
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258 | k = ftab[j] - 1;
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259 | ftab[j] = k;
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260 | fmap[k] = i;
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261 | }
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262 |
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263 | nBhtab = 2 + ((uint32_t)nblock / 32); /* bbox: unsigned div is easier */
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264 | for (i = 0; i < nBhtab; i++) bhtab[i] = 0;
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265 | for (i = 0; i < 256; i++) SET_BH(ftab[i]);
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266 |
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267 | /*
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268 | * Inductively refine the buckets. Kind-of an
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269 | * "exponential radix sort" (!), inspired by the
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270 | * Manber-Myers suffix array construction algorithm.
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271 | */
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272 |
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273 | /*-- set sentinel bits for block-end detection --*/
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274 | for (i = 0; i < 32; i++) {
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275 | SET_BH(nblock + 2*i);
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276 | CLEAR_BH(nblock + 2*i + 1);
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277 | }
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278 |
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279 | /*-- the log(N) loop --*/
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280 | H = 1;
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281 | while (1) {
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282 | j = 0;
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283 | for (i = 0; i < nblock; i++) {
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284 | if (ISSET_BH(i))
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285 | j = i;
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286 | k = fmap[i] - H;
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287 | if (k < 0)
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288 | k += nblock;
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289 | eclass[k] = j;
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290 | }
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291 |
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292 | nNotDone = 0;
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293 | r = -1;
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294 | while (1) {
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295 |
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296 | /*-- find the next non-singleton bucket --*/
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297 | k = r + 1;
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298 | while (ISSET_BH(k) && UNALIGNED_BH(k))
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299 | k++;
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300 | if (ISSET_BH(k)) {
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301 | while (WORD_BH(k) == 0xffffffff) k += 32;
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302 | while (ISSET_BH(k)) k++;
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303 | }
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304 | l = k - 1;
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305 | if (l >= nblock)
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306 | break;
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307 | while (!ISSET_BH(k) && UNALIGNED_BH(k))
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308 | k++;
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309 | if (!ISSET_BH(k)) {
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310 | while (WORD_BH(k) == 0x00000000) k += 32;
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311 | while (!ISSET_BH(k)) k++;
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312 | }
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313 | r = k - 1;
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314 | if (r >= nblock)
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315 | break;
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316 |
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317 | /*-- now [l, r] bracket current bucket --*/
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318 | if (r > l) {
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319 | nNotDone += (r - l + 1);
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320 | fallbackQSort3(fmap, eclass, l, r);
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321 |
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322 | /*-- scan bucket and generate header bits-- */
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323 | cc = -1;
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324 | for (i = l; i <= r; i++) {
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325 | cc1 = eclass[fmap[i]];
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326 | if (cc != cc1) {
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327 | SET_BH(i);
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328 | cc = cc1;
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329 | };
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330 | }
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331 | }
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332 | }
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333 |
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334 | H *= 2;
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335 | if (H > nblock || nNotDone == 0)
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336 | break;
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337 | }
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338 |
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339 | /*
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340 | * Reconstruct the original block in
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341 | * eclass8 [0 .. nblock-1], since the
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342 | * previous phase destroyed it.
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343 | */
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344 | j = 0;
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345 | for (i = 0; i < nblock; i++) {
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346 | while (ftabCopy[j] == 0)
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347 | j++;
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348 | ftabCopy[j]--;
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349 | eclass8[fmap[i]] = (uint8_t)j;
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350 | }
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351 | AssertH(j < 256, 1005);
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352 | }
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353 |
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354 | #undef SET_BH
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355 | #undef CLEAR_BH
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356 | #undef ISSET_BH
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357 | #undef WORD_BH
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358 | #undef UNALIGNED_BH
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359 |
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360 |
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361 | /*---------------------------------------------*/
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362 | /*--- The main, O(N^2 log(N)) sorting ---*/
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363 | /*--- algorithm. Faster for "normal" ---*/
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364 | /*--- non-repetitive blocks. ---*/
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365 | /*---------------------------------------------*/
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366 |
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367 | /*---------------------------------------------*/
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368 | static
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369 | NOINLINE
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370 | int mainGtU(
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371 | uint32_t i1,
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372 | uint32_t i2,
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373 | uint8_t* block,
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374 | uint16_t* quadrant,
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375 | uint32_t nblock,
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376 | int32_t* budget)
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377 | {
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378 | int32_t k;
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379 | uint8_t c1, c2;
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380 | uint16_t s1, s2;
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381 |
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382 | /* Loop unrolling here is actually very useful
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383 | * (generated code is much simpler),
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384 | * code size increase is only 270 bytes (i386)
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385 | * but speeds up compression 10% overall
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386 | */
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387 |
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388 | #if CONFIG_BZIP2_FEATURE_SPEED >= 1
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389 |
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390 | #define TIMES_8(code) \
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391 | code; code; code; code; \
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392 | code; code; code; code;
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393 | #define TIMES_12(code) \
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394 | code; code; code; code; \
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395 | code; code; code; code; \
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396 | code; code; code; code;
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397 |
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398 | #else
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399 |
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400 | #define TIMES_8(code) \
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401 | { \
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402 | int nn = 8; \
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403 | do { \
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404 | code; \
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405 | } while (--nn); \
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406 | }
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407 | #define TIMES_12(code) \
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408 | { \
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409 | int nn = 12; \
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410 | do { \
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411 | code; \
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412 | } while (--nn); \
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413 | }
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414 |
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415 | #endif
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416 |
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417 | AssertD(i1 != i2, "mainGtU");
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418 | TIMES_12(
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419 | c1 = block[i1]; c2 = block[i2];
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420 | if (c1 != c2) return (c1 > c2);
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421 | i1++; i2++;
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422 | )
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423 |
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424 | k = nblock + 8;
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425 |
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426 | do {
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427 | TIMES_8(
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428 | c1 = block[i1]; c2 = block[i2];
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429 | if (c1 != c2) return (c1 > c2);
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430 | s1 = quadrant[i1]; s2 = quadrant[i2];
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431 | if (s1 != s2) return (s1 > s2);
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432 | i1++; i2++;
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433 | )
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434 |
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435 | if (i1 >= nblock) i1 -= nblock;
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436 | if (i2 >= nblock) i2 -= nblock;
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437 |
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438 | (*budget)--;
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439 | k -= 8;
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440 | } while (k >= 0);
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441 |
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442 | return False;
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443 | }
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444 | #undef TIMES_8
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445 | #undef TIMES_12
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446 |
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447 | /*---------------------------------------------*/
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448 | /*
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449 | * Knuth's increments seem to work better
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450 | * than Incerpi-Sedgewick here. Possibly
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451 | * because the number of elems to sort is
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452 | * usually small, typically <= 20.
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453 | */
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454 | static
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455 | const int32_t incs[14] = {
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456 | 1, 4, 13, 40, 121, 364, 1093, 3280,
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457 | 9841, 29524, 88573, 265720,
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458 | 797161, 2391484
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459 | };
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460 |
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461 | static
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462 | void mainSimpleSort(uint32_t* ptr,
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463 | uint8_t* block,
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464 | uint16_t* quadrant,
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465 | int32_t nblock,
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466 | int32_t lo,
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467 | int32_t hi,
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468 | int32_t d,
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469 | int32_t* budget)
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470 | {
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471 | int32_t i, j, h, bigN, hp;
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472 | uint32_t v;
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473 |
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474 | bigN = hi - lo + 1;
|
---|
475 | if (bigN < 2) return;
|
---|
476 |
|
---|
477 | hp = 0;
|
---|
478 | while (incs[hp] < bigN) hp++;
|
---|
479 | hp--;
|
---|
480 |
|
---|
481 | for (; hp >= 0; hp--) {
|
---|
482 | h = incs[hp];
|
---|
483 |
|
---|
484 | i = lo + h;
|
---|
485 | while (1) {
|
---|
486 | /*-- copy 1 --*/
|
---|
487 | if (i > hi) break;
|
---|
488 | v = ptr[i];
|
---|
489 | j = i;
|
---|
490 | while (mainGtU(ptr[j-h]+d, v+d, block, quadrant, nblock, budget)) {
|
---|
491 | ptr[j] = ptr[j-h];
|
---|
492 | j = j - h;
|
---|
493 | if (j <= (lo + h - 1)) break;
|
---|
494 | }
|
---|
495 | ptr[j] = v;
|
---|
496 | i++;
|
---|
497 |
|
---|
498 | /* 1.5% overall speedup, +290 bytes */
|
---|
499 | #if CONFIG_BZIP2_FEATURE_SPEED >= 3
|
---|
500 | /*-- copy 2 --*/
|
---|
501 | if (i > hi) break;
|
---|
502 | v = ptr[i];
|
---|
503 | j = i;
|
---|
504 | while (mainGtU(ptr[j-h]+d, v+d, block, quadrant, nblock, budget)) {
|
---|
505 | ptr[j] = ptr[j-h];
|
---|
506 | j = j - h;
|
---|
507 | if (j <= (lo + h - 1)) break;
|
---|
508 | }
|
---|
509 | ptr[j] = v;
|
---|
510 | i++;
|
---|
511 |
|
---|
512 | /*-- copy 3 --*/
|
---|
513 | if (i > hi) break;
|
---|
514 | v = ptr[i];
|
---|
515 | j = i;
|
---|
516 | while (mainGtU(ptr[j-h]+d, v+d, block, quadrant, nblock, budget)) {
|
---|
517 | ptr[j] = ptr[j-h];
|
---|
518 | j = j - h;
|
---|
519 | if (j <= (lo + h - 1)) break;
|
---|
520 | }
|
---|
521 | ptr[j] = v;
|
---|
522 | i++;
|
---|
523 | #endif
|
---|
524 | if (*budget < 0) return;
|
---|
525 | }
|
---|
526 | }
|
---|
527 | }
|
---|
528 |
|
---|
529 |
|
---|
530 | /*---------------------------------------------*/
|
---|
531 | /*
|
---|
532 | * The following is an implementation of
|
---|
533 | * an elegant 3-way quicksort for strings,
|
---|
534 | * described in a paper "Fast Algorithms for
|
---|
535 | * Sorting and Searching Strings", by Robert
|
---|
536 | * Sedgewick and Jon L. Bentley.
|
---|
537 | */
|
---|
538 |
|
---|
539 | static
|
---|
540 | ALWAYS_INLINE
|
---|
541 | uint8_t mmed3(uint8_t a, uint8_t b, uint8_t c)
|
---|
542 | {
|
---|
543 | uint8_t t;
|
---|
544 | if (a > b) {
|
---|
545 | t = a;
|
---|
546 | a = b;
|
---|
547 | b = t;
|
---|
548 | };
|
---|
549 | /* here b >= a */
|
---|
550 | if (b > c) {
|
---|
551 | b = c;
|
---|
552 | if (a > b)
|
---|
553 | b = a;
|
---|
554 | }
|
---|
555 | return b;
|
---|
556 | }
|
---|
557 |
|
---|
558 | #define mpush(lz,hz,dz) \
|
---|
559 | { \
|
---|
560 | stackLo[sp] = lz; \
|
---|
561 | stackHi[sp] = hz; \
|
---|
562 | stackD [sp] = dz; \
|
---|
563 | sp++; \
|
---|
564 | }
|
---|
565 |
|
---|
566 | #define mpop(lz,hz,dz) \
|
---|
567 | { \
|
---|
568 | sp--; \
|
---|
569 | lz = stackLo[sp]; \
|
---|
570 | hz = stackHi[sp]; \
|
---|
571 | dz = stackD [sp]; \
|
---|
572 | }
|
---|
573 |
|
---|
574 | #define mnextsize(az) (nextHi[az] - nextLo[az])
|
---|
575 |
|
---|
576 | #define mnextswap(az,bz) \
|
---|
577 | { \
|
---|
578 | int32_t tz; \
|
---|
579 | tz = nextLo[az]; nextLo[az] = nextLo[bz]; nextLo[bz] = tz; \
|
---|
580 | tz = nextHi[az]; nextHi[az] = nextHi[bz]; nextHi[bz] = tz; \
|
---|
581 | tz = nextD [az]; nextD [az] = nextD [bz]; nextD [bz] = tz; \
|
---|
582 | }
|
---|
583 |
|
---|
584 | #define MAIN_QSORT_SMALL_THRESH 20
|
---|
585 | #define MAIN_QSORT_DEPTH_THRESH (BZ_N_RADIX + BZ_N_QSORT)
|
---|
586 | #define MAIN_QSORT_STACK_SIZE 100
|
---|
587 |
|
---|
588 | static NOINLINE
|
---|
589 | void mainQSort3(uint32_t* ptr,
|
---|
590 | uint8_t* block,
|
---|
591 | uint16_t* quadrant,
|
---|
592 | int32_t nblock,
|
---|
593 | int32_t loSt,
|
---|
594 | int32_t hiSt,
|
---|
595 | int32_t dSt,
|
---|
596 | int32_t* budget)
|
---|
597 | {
|
---|
598 | int32_t unLo, unHi, ltLo, gtHi, n, m, med;
|
---|
599 | int32_t sp, lo, hi, d;
|
---|
600 |
|
---|
601 | int32_t stackLo[MAIN_QSORT_STACK_SIZE];
|
---|
602 | int32_t stackHi[MAIN_QSORT_STACK_SIZE];
|
---|
603 | int32_t stackD [MAIN_QSORT_STACK_SIZE];
|
---|
604 |
|
---|
605 | int32_t nextLo[3];
|
---|
606 | int32_t nextHi[3];
|
---|
607 | int32_t nextD [3];
|
---|
608 |
|
---|
609 | sp = 0;
|
---|
610 | mpush(loSt, hiSt, dSt);
|
---|
611 |
|
---|
612 | while (sp > 0) {
|
---|
613 | AssertH(sp < MAIN_QSORT_STACK_SIZE - 2, 1001);
|
---|
614 |
|
---|
615 | mpop(lo, hi, d);
|
---|
616 | if (hi - lo < MAIN_QSORT_SMALL_THRESH
|
---|
617 | || d > MAIN_QSORT_DEPTH_THRESH
|
---|
618 | ) {
|
---|
619 | mainSimpleSort(ptr, block, quadrant, nblock, lo, hi, d, budget);
|
---|
620 | if (*budget < 0)
|
---|
621 | return;
|
---|
622 | continue;
|
---|
623 | }
|
---|
624 | med = (int32_t) mmed3(block[ptr[lo ] + d],
|
---|
625 | block[ptr[hi ] + d],
|
---|
626 | block[ptr[(lo+hi) >> 1] + d]);
|
---|
627 |
|
---|
628 | unLo = ltLo = lo;
|
---|
629 | unHi = gtHi = hi;
|
---|
630 |
|
---|
631 | while (1) {
|
---|
632 | while (1) {
|
---|
633 | if (unLo > unHi)
|
---|
634 | break;
|
---|
635 | n = ((int32_t)block[ptr[unLo]+d]) - med;
|
---|
636 | if (n == 0) {
|
---|
637 | mswap(ptr[unLo], ptr[ltLo]);
|
---|
638 | ltLo++;
|
---|
639 | unLo++;
|
---|
640 | continue;
|
---|
641 | };
|
---|
642 | if (n > 0) break;
|
---|
643 | unLo++;
|
---|
644 | }
|
---|
645 | while (1) {
|
---|
646 | if (unLo > unHi)
|
---|
647 | break;
|
---|
648 | n = ((int32_t)block[ptr[unHi]+d]) - med;
|
---|
649 | if (n == 0) {
|
---|
650 | mswap(ptr[unHi], ptr[gtHi]);
|
---|
651 | gtHi--;
|
---|
652 | unHi--;
|
---|
653 | continue;
|
---|
654 | };
|
---|
655 | if (n < 0) break;
|
---|
656 | unHi--;
|
---|
657 | }
|
---|
658 | if (unLo > unHi)
|
---|
659 | break;
|
---|
660 | mswap(ptr[unLo], ptr[unHi]);
|
---|
661 | unLo++;
|
---|
662 | unHi--;
|
---|
663 | }
|
---|
664 |
|
---|
665 | AssertD(unHi == unLo-1, "mainQSort3(2)");
|
---|
666 |
|
---|
667 | if (gtHi < ltLo) {
|
---|
668 | mpush(lo, hi, d + 1);
|
---|
669 | continue;
|
---|
670 | }
|
---|
671 |
|
---|
672 | n = mmin(ltLo-lo, unLo-ltLo); mvswap(ptr, lo, unLo-n, n);
|
---|
673 | m = mmin(hi-gtHi, gtHi-unHi); mvswap(ptr, unLo, hi-m+1, m);
|
---|
674 |
|
---|
675 | n = lo + unLo - ltLo - 1;
|
---|
676 | m = hi - (gtHi - unHi) + 1;
|
---|
677 |
|
---|
678 | nextLo[0] = lo; nextHi[0] = n; nextD[0] = d;
|
---|
679 | nextLo[1] = m; nextHi[1] = hi; nextD[1] = d;
|
---|
680 | nextLo[2] = n+1; nextHi[2] = m-1; nextD[2] = d+1;
|
---|
681 |
|
---|
682 | if (mnextsize(0) < mnextsize(1)) mnextswap(0, 1);
|
---|
683 | if (mnextsize(1) < mnextsize(2)) mnextswap(1, 2);
|
---|
684 | if (mnextsize(0) < mnextsize(1)) mnextswap(0, 1);
|
---|
685 |
|
---|
686 | AssertD (mnextsize(0) >= mnextsize(1), "mainQSort3(8)");
|
---|
687 | AssertD (mnextsize(1) >= mnextsize(2), "mainQSort3(9)");
|
---|
688 |
|
---|
689 | mpush(nextLo[0], nextHi[0], nextD[0]);
|
---|
690 | mpush(nextLo[1], nextHi[1], nextD[1]);
|
---|
691 | mpush(nextLo[2], nextHi[2], nextD[2]);
|
---|
692 | }
|
---|
693 | }
|
---|
694 |
|
---|
695 | #undef mpush
|
---|
696 | #undef mpop
|
---|
697 | #undef mnextsize
|
---|
698 | #undef mnextswap
|
---|
699 | #undef MAIN_QSORT_SMALL_THRESH
|
---|
700 | #undef MAIN_QSORT_DEPTH_THRESH
|
---|
701 | #undef MAIN_QSORT_STACK_SIZE
|
---|
702 |
|
---|
703 |
|
---|
704 | /*---------------------------------------------*/
|
---|
705 | /* Pre:
|
---|
706 | * nblock > N_OVERSHOOT
|
---|
707 | * block32 exists for [0 .. nblock-1 +N_OVERSHOOT]
|
---|
708 | * ((uint8_t*)block32) [0 .. nblock-1] holds block
|
---|
709 | * ptr exists for [0 .. nblock-1]
|
---|
710 | *
|
---|
711 | * Post:
|
---|
712 | * ((uint8_t*)block32) [0 .. nblock-1] holds block
|
---|
713 | * All other areas of block32 destroyed
|
---|
714 | * ftab[0 .. 65536] destroyed
|
---|
715 | * ptr [0 .. nblock-1] holds sorted order
|
---|
716 | * if (*budget < 0), sorting was abandoned
|
---|
717 | */
|
---|
718 |
|
---|
719 | #define BIGFREQ(b) (ftab[((b)+1) << 8] - ftab[(b) << 8])
|
---|
720 | #define SETMASK (1 << 21)
|
---|
721 | #define CLEARMASK (~(SETMASK))
|
---|
722 |
|
---|
723 | static NOINLINE
|
---|
724 | void mainSort(EState* state,
|
---|
725 | uint32_t* ptr,
|
---|
726 | uint8_t* block,
|
---|
727 | uint16_t* quadrant,
|
---|
728 | uint32_t* ftab,
|
---|
729 | int32_t nblock,
|
---|
730 | int32_t* budget)
|
---|
731 | {
|
---|
732 | int32_t i, j, k, ss, sb;
|
---|
733 | uint8_t c1;
|
---|
734 | int32_t numQSorted;
|
---|
735 | uint16_t s;
|
---|
736 | Bool bigDone[256];
|
---|
737 | /* bbox: moved to EState to save stack
|
---|
738 | int32_t runningOrder[256];
|
---|
739 | int32_t copyStart[256];
|
---|
740 | int32_t copyEnd [256];
|
---|
741 | */
|
---|
742 | #define runningOrder (state->mainSort__runningOrder)
|
---|
743 | #define copyStart (state->mainSort__copyStart)
|
---|
744 | #define copyEnd (state->mainSort__copyEnd)
|
---|
745 |
|
---|
746 | /*-- set up the 2-byte frequency table --*/
|
---|
747 | /* was: for (i = 65536; i >= 0; i--) ftab[i] = 0; */
|
---|
748 | memset(ftab, 0, 65537 * sizeof(ftab[0]));
|
---|
749 |
|
---|
750 | j = block[0] << 8;
|
---|
751 | i = nblock - 1;
|
---|
752 | /* 3%, +300 bytes */
|
---|
753 | #if CONFIG_BZIP2_FEATURE_SPEED >= 2
|
---|
754 | for (; i >= 3; i -= 4) {
|
---|
755 | quadrant[i] = 0;
|
---|
756 | j = (j >> 8) | (((uint16_t)block[i]) << 8);
|
---|
757 | ftab[j]++;
|
---|
758 | quadrant[i-1] = 0;
|
---|
759 | j = (j >> 8) | (((uint16_t)block[i-1]) << 8);
|
---|
760 | ftab[j]++;
|
---|
761 | quadrant[i-2] = 0;
|
---|
762 | j = (j >> 8) | (((uint16_t)block[i-2]) << 8);
|
---|
763 | ftab[j]++;
|
---|
764 | quadrant[i-3] = 0;
|
---|
765 | j = (j >> 8) | (((uint16_t)block[i-3]) << 8);
|
---|
766 | ftab[j]++;
|
---|
767 | }
|
---|
768 | #endif
|
---|
769 | for (; i >= 0; i--) {
|
---|
770 | quadrant[i] = 0;
|
---|
771 | j = (j >> 8) | (((uint16_t)block[i]) << 8);
|
---|
772 | ftab[j]++;
|
---|
773 | }
|
---|
774 |
|
---|
775 | /*-- (emphasises close relationship of block & quadrant) --*/
|
---|
776 | for (i = 0; i < BZ_N_OVERSHOOT; i++) {
|
---|
777 | block [nblock+i] = block[i];
|
---|
778 | quadrant[nblock+i] = 0;
|
---|
779 | }
|
---|
780 |
|
---|
781 | /*-- Complete the initial radix sort --*/
|
---|
782 | j = ftab[0]; /* bbox: optimized */
|
---|
783 | for (i = 1; i <= 65536; i++) {
|
---|
784 | j += ftab[i];
|
---|
785 | ftab[i] = j;
|
---|
786 | }
|
---|
787 |
|
---|
788 | s = block[0] << 8;
|
---|
789 | i = nblock - 1;
|
---|
790 | #if CONFIG_BZIP2_FEATURE_SPEED >= 2
|
---|
791 | for (; i >= 3; i -= 4) {
|
---|
792 | s = (s >> 8) | (block[i] << 8);
|
---|
793 | j = ftab[s] - 1;
|
---|
794 | ftab[s] = j;
|
---|
795 | ptr[j] = i;
|
---|
796 | s = (s >> 8) | (block[i-1] << 8);
|
---|
797 | j = ftab[s] - 1;
|
---|
798 | ftab[s] = j;
|
---|
799 | ptr[j] = i-1;
|
---|
800 | s = (s >> 8) | (block[i-2] << 8);
|
---|
801 | j = ftab[s] - 1;
|
---|
802 | ftab[s] = j;
|
---|
803 | ptr[j] = i-2;
|
---|
804 | s = (s >> 8) | (block[i-3] << 8);
|
---|
805 | j = ftab[s] - 1;
|
---|
806 | ftab[s] = j;
|
---|
807 | ptr[j] = i-3;
|
---|
808 | }
|
---|
809 | #endif
|
---|
810 | for (; i >= 0; i--) {
|
---|
811 | s = (s >> 8) | (block[i] << 8);
|
---|
812 | j = ftab[s] - 1;
|
---|
813 | ftab[s] = j;
|
---|
814 | ptr[j] = i;
|
---|
815 | }
|
---|
816 |
|
---|
817 | /*
|
---|
818 | * Now ftab contains the first loc of every small bucket.
|
---|
819 | * Calculate the running order, from smallest to largest
|
---|
820 | * big bucket.
|
---|
821 | */
|
---|
822 | for (i = 0; i <= 255; i++) {
|
---|
823 | bigDone [i] = False;
|
---|
824 | runningOrder[i] = i;
|
---|
825 | }
|
---|
826 |
|
---|
827 | {
|
---|
828 | int32_t vv;
|
---|
829 | /* bbox: was: int32_t h = 1; */
|
---|
830 | /* do h = 3 * h + 1; while (h <= 256); */
|
---|
831 | uint32_t h = 364;
|
---|
832 |
|
---|
833 | do {
|
---|
834 | /*h = h / 3;*/
|
---|
835 | h = (h * 171) >> 9; /* bbox: fast h/3 */
|
---|
836 | for (i = h; i <= 255; i++) {
|
---|
837 | vv = runningOrder[i];
|
---|
838 | j = i;
|
---|
839 | while (BIGFREQ(runningOrder[j-h]) > BIGFREQ(vv)) {
|
---|
840 | runningOrder[j] = runningOrder[j-h];
|
---|
841 | j = j - h;
|
---|
842 | if (j <= (h - 1))
|
---|
843 | goto zero;
|
---|
844 | }
|
---|
845 | zero:
|
---|
846 | runningOrder[j] = vv;
|
---|
847 | }
|
---|
848 | } while (h != 1);
|
---|
849 | }
|
---|
850 |
|
---|
851 | /*
|
---|
852 | * The main sorting loop.
|
---|
853 | */
|
---|
854 |
|
---|
855 | numQSorted = 0;
|
---|
856 |
|
---|
857 | for (i = 0; i <= 255; i++) {
|
---|
858 |
|
---|
859 | /*
|
---|
860 | * Process big buckets, starting with the least full.
|
---|
861 | * Basically this is a 3-step process in which we call
|
---|
862 | * mainQSort3 to sort the small buckets [ss, j], but
|
---|
863 | * also make a big effort to avoid the calls if we can.
|
---|
864 | */
|
---|
865 | ss = runningOrder[i];
|
---|
866 |
|
---|
867 | /*
|
---|
868 | * Step 1:
|
---|
869 | * Complete the big bucket [ss] by quicksorting
|
---|
870 | * any unsorted small buckets [ss, j], for j != ss.
|
---|
871 | * Hopefully previous pointer-scanning phases have already
|
---|
872 | * completed many of the small buckets [ss, j], so
|
---|
873 | * we don't have to sort them at all.
|
---|
874 | */
|
---|
875 | for (j = 0; j <= 255; j++) {
|
---|
876 | if (j != ss) {
|
---|
877 | sb = (ss << 8) + j;
|
---|
878 | if (!(ftab[sb] & SETMASK)) {
|
---|
879 | int32_t lo = ftab[sb] & CLEARMASK;
|
---|
880 | int32_t hi = (ftab[sb+1] & CLEARMASK) - 1;
|
---|
881 | if (hi > lo) {
|
---|
882 | mainQSort3(
|
---|
883 | ptr, block, quadrant, nblock,
|
---|
884 | lo, hi, BZ_N_RADIX, budget
|
---|
885 | );
|
---|
886 | if (*budget < 0) return;
|
---|
887 | numQSorted += (hi - lo + 1);
|
---|
888 | }
|
---|
889 | }
|
---|
890 | ftab[sb] |= SETMASK;
|
---|
891 | }
|
---|
892 | }
|
---|
893 |
|
---|
894 | AssertH(!bigDone[ss], 1006);
|
---|
895 |
|
---|
896 | /*
|
---|
897 | * Step 2:
|
---|
898 | * Now scan this big bucket [ss] so as to synthesise the
|
---|
899 | * sorted order for small buckets [t, ss] for all t,
|
---|
900 | * including, magically, the bucket [ss,ss] too.
|
---|
901 | * This will avoid doing Real Work in subsequent Step 1's.
|
---|
902 | */
|
---|
903 | {
|
---|
904 | for (j = 0; j <= 255; j++) {
|
---|
905 | copyStart[j] = ftab[(j << 8) + ss] & CLEARMASK;
|
---|
906 | copyEnd [j] = (ftab[(j << 8) + ss + 1] & CLEARMASK) - 1;
|
---|
907 | }
|
---|
908 | for (j = ftab[ss << 8] & CLEARMASK; j < copyStart[ss]; j++) {
|
---|
909 | k = ptr[j] - 1;
|
---|
910 | if (k < 0)
|
---|
911 | k += nblock;
|
---|
912 | c1 = block[k];
|
---|
913 | if (!bigDone[c1])
|
---|
914 | ptr[copyStart[c1]++] = k;
|
---|
915 | }
|
---|
916 | for (j = (ftab[(ss+1) << 8] & CLEARMASK) - 1; j > copyEnd[ss]; j--) {
|
---|
917 | k = ptr[j]-1;
|
---|
918 | if (k < 0)
|
---|
919 | k += nblock;
|
---|
920 | c1 = block[k];
|
---|
921 | if (!bigDone[c1])
|
---|
922 | ptr[copyEnd[c1]--] = k;
|
---|
923 | }
|
---|
924 | }
|
---|
925 |
|
---|
926 | /* Extremely rare case missing in bzip2-1.0.0 and 1.0.1.
|
---|
927 | * Necessity for this case is demonstrated by compressing
|
---|
928 | * a sequence of approximately 48.5 million of character
|
---|
929 | * 251; 1.0.0/1.0.1 will then die here. */
|
---|
930 | AssertH((copyStart[ss]-1 == copyEnd[ss]) \
|
---|
931 | || (copyStart[ss] == 0 && copyEnd[ss] == nblock-1), 1007);
|
---|
932 |
|
---|
933 | for (j = 0; j <= 255; j++)
|
---|
934 | ftab[(j << 8) + ss] |= SETMASK;
|
---|
935 |
|
---|
936 | /*
|
---|
937 | * Step 3:
|
---|
938 | * The [ss] big bucket is now done. Record this fact,
|
---|
939 | * and update the quadrant descriptors. Remember to
|
---|
940 | * update quadrants in the overshoot area too, if
|
---|
941 | * necessary. The "if (i < 255)" test merely skips
|
---|
942 | * this updating for the last bucket processed, since
|
---|
943 | * updating for the last bucket is pointless.
|
---|
944 | *
|
---|
945 | * The quadrant array provides a way to incrementally
|
---|
946 | * cache sort orderings, as they appear, so as to
|
---|
947 | * make subsequent comparisons in fullGtU() complete
|
---|
948 | * faster. For repetitive blocks this makes a big
|
---|
949 | * difference (but not big enough to be able to avoid
|
---|
950 | * the fallback sorting mechanism, exponential radix sort).
|
---|
951 | *
|
---|
952 | * The precise meaning is: at all times:
|
---|
953 | *
|
---|
954 | * for 0 <= i < nblock and 0 <= j <= nblock
|
---|
955 | *
|
---|
956 | * if block[i] != block[j],
|
---|
957 | *
|
---|
958 | * then the relative values of quadrant[i] and
|
---|
959 | * quadrant[j] are meaningless.
|
---|
960 | *
|
---|
961 | * else {
|
---|
962 | * if quadrant[i] < quadrant[j]
|
---|
963 | * then the string starting at i lexicographically
|
---|
964 | * precedes the string starting at j
|
---|
965 | *
|
---|
966 | * else if quadrant[i] > quadrant[j]
|
---|
967 | * then the string starting at j lexicographically
|
---|
968 | * precedes the string starting at i
|
---|
969 | *
|
---|
970 | * else
|
---|
971 | * the relative ordering of the strings starting
|
---|
972 | * at i and j has not yet been determined.
|
---|
973 | * }
|
---|
974 | */
|
---|
975 | bigDone[ss] = True;
|
---|
976 |
|
---|
977 | if (i < 255) {
|
---|
978 | int32_t bbStart = ftab[ss << 8] & CLEARMASK;
|
---|
979 | int32_t bbSize = (ftab[(ss+1) << 8] & CLEARMASK) - bbStart;
|
---|
980 | int32_t shifts = 0;
|
---|
981 |
|
---|
982 | while ((bbSize >> shifts) > 65534) shifts++;
|
---|
983 |
|
---|
984 | for (j = bbSize-1; j >= 0; j--) {
|
---|
985 | int32_t a2update = ptr[bbStart + j];
|
---|
986 | uint16_t qVal = (uint16_t)(j >> shifts);
|
---|
987 | quadrant[a2update] = qVal;
|
---|
988 | if (a2update < BZ_N_OVERSHOOT)
|
---|
989 | quadrant[a2update + nblock] = qVal;
|
---|
990 | }
|
---|
991 | AssertH(((bbSize-1) >> shifts) <= 65535, 1002);
|
---|
992 | }
|
---|
993 | }
|
---|
994 | #undef runningOrder
|
---|
995 | #undef copyStart
|
---|
996 | #undef copyEnd
|
---|
997 | }
|
---|
998 |
|
---|
999 | #undef BIGFREQ
|
---|
1000 | #undef SETMASK
|
---|
1001 | #undef CLEARMASK
|
---|
1002 |
|
---|
1003 |
|
---|
1004 | /*---------------------------------------------*/
|
---|
1005 | /* Pre:
|
---|
1006 | * nblock > 0
|
---|
1007 | * arr2 exists for [0 .. nblock-1 +N_OVERSHOOT]
|
---|
1008 | * ((uint8_t*)arr2)[0 .. nblock-1] holds block
|
---|
1009 | * arr1 exists for [0 .. nblock-1]
|
---|
1010 | *
|
---|
1011 | * Post:
|
---|
1012 | * ((uint8_t*)arr2) [0 .. nblock-1] holds block
|
---|
1013 | * All other areas of block destroyed
|
---|
1014 | * ftab[0 .. 65536] destroyed
|
---|
1015 | * arr1[0 .. nblock-1] holds sorted order
|
---|
1016 | */
|
---|
1017 | static NOINLINE
|
---|
1018 | void BZ2_blockSort(EState* s)
|
---|
1019 | {
|
---|
1020 | /* In original bzip2 1.0.4, it's a parameter, but 30
|
---|
1021 | * (which was the default) should work ok. */
|
---|
1022 | enum { wfact = 30 };
|
---|
1023 |
|
---|
1024 | uint32_t* ptr = s->ptr;
|
---|
1025 | uint8_t* block = s->block;
|
---|
1026 | uint32_t* ftab = s->ftab;
|
---|
1027 | int32_t nblock = s->nblock;
|
---|
1028 | uint16_t* quadrant;
|
---|
1029 | int32_t budget;
|
---|
1030 | int32_t i;
|
---|
1031 |
|
---|
1032 | if (nblock < 10000) {
|
---|
1033 | fallbackSort(s->arr1, s->arr2, ftab, nblock);
|
---|
1034 | } else {
|
---|
1035 | /* Calculate the location for quadrant, remembering to get
|
---|
1036 | * the alignment right. Assumes that &(block[0]) is at least
|
---|
1037 | * 2-byte aligned -- this should be ok since block is really
|
---|
1038 | * the first section of arr2.
|
---|
1039 | */
|
---|
1040 | i = nblock + BZ_N_OVERSHOOT;
|
---|
1041 | if (i & 1) i++;
|
---|
1042 | quadrant = (uint16_t*)(&(block[i]));
|
---|
1043 |
|
---|
1044 | /* (wfact-1) / 3 puts the default-factor-30
|
---|
1045 | * transition point at very roughly the same place as
|
---|
1046 | * with v0.1 and v0.9.0.
|
---|
1047 | * Not that it particularly matters any more, since the
|
---|
1048 | * resulting compressed stream is now the same regardless
|
---|
1049 | * of whether or not we use the main sort or fallback sort.
|
---|
1050 | */
|
---|
1051 | budget = nblock * ((wfact-1) / 3);
|
---|
1052 |
|
---|
1053 | mainSort(s, ptr, block, quadrant, ftab, nblock, &budget);
|
---|
1054 | if (budget < 0) {
|
---|
1055 | fallbackSort(s->arr1, s->arr2, ftab, nblock);
|
---|
1056 | }
|
---|
1057 | }
|
---|
1058 |
|
---|
1059 | s->origPtr = -1;
|
---|
1060 | for (i = 0; i < s->nblock; i++)
|
---|
1061 | if (ptr[i] == 0) {
|
---|
1062 | s->origPtr = i;
|
---|
1063 | break;
|
---|
1064 | };
|
---|
1065 |
|
---|
1066 | AssertH(s->origPtr != -1, 1003);
|
---|
1067 | }
|
---|
1068 |
|
---|
1069 |
|
---|
1070 | /*-------------------------------------------------------------*/
|
---|
1071 | /*--- end blocksort.c ---*/
|
---|
1072 | /*-------------------------------------------------------------*/
|
---|