Coverage Report

Created: 2023-03-26 06:14

/src/libxml2/timsort.h
Line
Count
Source (jump to first uncovered line)
1
/*
2
 * Taken from https://github.com/swenson/sort
3
 * Revision: 05fd77bfec049ce8b7c408c4d3dd2d51ee061a15
4
 * Removed all code unrelated to Timsort and made minor adjustments for
5
 * cross-platform compatibility.
6
 */
7
8
/*
9
 * The MIT License (MIT)
10
 *
11
 * Copyright (c) 2010-2017 Christopher Swenson.
12
 * Copyright (c) 2012 Vojtech Fried.
13
 * Copyright (c) 2012 Google Inc. All Rights Reserved.
14
 *
15
 * Permission is hereby granted, free of charge, to any person obtaining a
16
 * copy of this software and associated documentation files (the "Software"),
17
 * to deal in the Software without restriction, including without limitation
18
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19
 * and/or sell copies of the Software, and to permit persons to whom the
20
 * Software is furnished to do so, subject to the following conditions:
21
 *
22
 * The above copyright notice and this permission notice shall be included in
23
 * all copies or substantial portions of the Software.
24
 *
25
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
31
 * DEALINGS IN THE SOFTWARE.
32
 */
33
34
#include <stdlib.h>
35
#include <stdio.h>
36
#include <string.h>
37
#ifdef HAVE_STDINT_H
38
#include <stdint.h>
39
#elif defined(_WIN32)
40
typedef unsigned __int64 uint64_t;
41
#endif
42
43
#ifndef SORT_NAME
44
#error "Must declare SORT_NAME"
45
#endif
46
47
#ifndef SORT_TYPE
48
#error "Must declare SORT_TYPE"
49
#endif
50
51
#ifndef SORT_CMP
52
#define SORT_CMP(x, y)  ((x) < (y) ? -1 : ((x) == (y) ? 0 : 1))
53
#endif
54
55
#ifndef TIM_SORT_STACK_SIZE
56
#define TIM_SORT_STACK_SIZE 128
57
#endif
58
59
3.33k
#define SORT_SWAP(x,y) {SORT_TYPE __SORT_SWAP_t = (x); (x) = (y); (y) = __SORT_SWAP_t;}
60
61
62
/* Common, type-agnostic functions and constants that we don't want to declare twice. */
63
#ifndef SORT_COMMON_H
64
#define SORT_COMMON_H
65
66
#ifndef MAX
67
9.91k
#define MAX(x,y) (((x) > (y) ? (x) : (y)))
68
#endif
69
70
#ifndef MIN
71
17.1k
#define MIN(x,y) (((x) < (y) ? (x) : (y)))
72
#endif
73
74
static int compute_minrun(const uint64_t);
75
76
#ifndef CLZ
77
#if defined(__GNUC__) && ((__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || (__GNUC__ > 3))
78
9.91k
#define CLZ __builtin_clzll
79
#else
80
81
static int clzll(uint64_t);
82
83
/* adapted from Hacker's Delight */
84
static int clzll(uint64_t x) {
85
  int n;
86
87
  if (x == 0) {
88
    return 64;
89
  }
90
91
  n = 0;
92
93
  if (x <= 0x00000000FFFFFFFFL) {
94
    n = n + 32;
95
    x = x << 32;
96
  }
97
98
  if (x <= 0x0000FFFFFFFFFFFFL) {
99
    n = n + 16;
100
    x = x << 16;
101
  }
102
103
  if (x <= 0x00FFFFFFFFFFFFFFL) {
104
    n = n + 8;
105
    x = x << 8;
106
  }
107
108
  if (x <= 0x0FFFFFFFFFFFFFFFL) {
109
    n = n + 4;
110
    x = x << 4;
111
  }
112
113
  if (x <= 0x3FFFFFFFFFFFFFFFL) {
114
    n = n + 2;
115
    x = x << 2;
116
  }
117
118
  if (x <= 0x7FFFFFFFFFFFFFFFL) {
119
    n = n + 1;
120
  }
121
122
  return n;
123
}
124
125
#define CLZ clzll
126
#endif
127
#endif
128
129
9.91k
static __inline int compute_minrun(const uint64_t size) {
130
9.91k
  const int top_bit = 64 - CLZ(size);
131
9.91k
  const int shift = MAX(top_bit, 6) - 6;
132
9.91k
  const int minrun = size >> shift;
133
9.91k
  const uint64_t mask = (1ULL << shift) - 1;
134
135
9.91k
  if (mask & size) {
136
6.76k
    return minrun + 1;
137
6.76k
  }
138
139
3.15k
  return minrun;
140
9.91k
}
141
142
#endif /* SORT_COMMON_H */
143
144
703k
#define SORT_CONCAT(x, y) x ## _ ## y
145
703k
#define SORT_MAKE_STR1(x, y) SORT_CONCAT(x,y)
146
703k
#define SORT_MAKE_STR(x) SORT_MAKE_STR1(SORT_NAME,x)
147
148
267k
#define BINARY_INSERTION_FIND          SORT_MAKE_STR(binary_insertion_find)
149
184k
#define BINARY_INSERTION_SORT_START    SORT_MAKE_STR(binary_insertion_sort_start)
150
175k
#define BINARY_INSERTION_SORT          SORT_MAKE_STR(binary_insertion_sort)
151
3.09k
#define REVERSE_ELEMENTS               SORT_MAKE_STR(reverse_elements)
152
27.1k
#define COUNT_RUN                      SORT_MAKE_STR(count_run)
153
7.89k
#define CHECK_INVARIANT                SORT_MAKE_STR(check_invariant)
154
#define TIM_SORT                       SORT_MAKE_STR(tim_sort)
155
17.1k
#define TIM_SORT_RESIZE                SORT_MAKE_STR(tim_sort_resize)
156
17.1k
#define TIM_SORT_MERGE                 SORT_MAKE_STR(tim_sort_merge)
157
3.42k
#define TIM_SORT_COLLAPSE              SORT_MAKE_STR(tim_sort_collapse)
158
159
#ifndef MAX
160
#define MAX(x,y) (((x) > (y) ? (x) : (y)))
161
#endif
162
#ifndef MIN
163
#define MIN(x,y) (((x) < (y) ? (x) : (y)))
164
#endif
165
166
typedef struct {
167
  size_t start;
168
  size_t length;
169
} TIM_SORT_RUN_T;
170
171
172
void BINARY_INSERTION_SORT(SORT_TYPE *dst, const size_t size);
173
void TIM_SORT(SORT_TYPE *dst, const size_t size);
174
175
176
/* Function used to do a binary search for binary insertion sort */
177
static __inline size_t BINARY_INSERTION_FIND(SORT_TYPE *dst, const SORT_TYPE x,
178
267k
    const size_t size) {
179
267k
  size_t l, c, r;
180
267k
  SORT_TYPE cx;
181
267k
  l = 0;
182
267k
  r = size - 1;
183
267k
  c = r >> 1;
184
185
  /* check for out of bounds at the beginning. */
186
267k
  if (SORT_CMP(x, dst[0]) < 0) {
187
25.1k
    return 0;
188
242k
  } else if (SORT_CMP(x, dst[r]) > 0) {
189
0
    return r;
190
0
  }
191
192
242k
  cx = dst[c];
193
194
929k
  while (1) {
195
929k
    const int val = SORT_CMP(x, cx);
196
197
929k
    if (val < 0) {
198
140k
      if (c - l <= 1) {
199
52.3k
        return c;
200
52.3k
      }
201
202
88.4k
      r = c;
203
788k
    } else { /* allow = for stability. The binary search favors the right. */
204
788k
      if (r - c <= 1) {
205
189k
        return c + 1;
206
189k
      }
207
208
599k
      l = c;
209
599k
    }
210
211
687k
    c = l + ((r - l) >> 1);
212
687k
    cx = dst[c];
213
687k
  }
214
242k
}
215
216
/* Binary insertion sort, but knowing that the first "start" entries are sorted.  Used in timsort. */
217
184k
static void BINARY_INSERTION_SORT_START(SORT_TYPE *dst, const size_t start, const size_t size) {
218
184k
  size_t i;
219
220
1.43M
  for (i = start; i < size; i++) {
221
1.25M
    size_t j;
222
1.25M
    SORT_TYPE x;
223
1.25M
    size_t location;
224
225
    /* If this entry is already correct, just move along */
226
1.25M
    if (SORT_CMP(dst[i - 1], dst[i]) <= 0) {
227
987k
      continue;
228
987k
    }
229
230
    /* Else we need to find the right place, shift everything over, and squeeze in */
231
267k
    x = dst[i];
232
267k
    location = BINARY_INSERTION_FIND(dst, x, i);
233
234
1.25M
    for (j = i - 1; j >= location; j--) {
235
1.01M
      dst[j + 1] = dst[j];
236
237
1.01M
      if (j == 0) { /* check edge case because j is unsigned */
238
25.1k
        break;
239
25.1k
      }
240
1.01M
    }
241
242
267k
    dst[location] = x;
243
267k
  }
244
184k
}
245
246
/* Binary insertion sort */
247
175k
void BINARY_INSERTION_SORT(SORT_TYPE *dst, const size_t size) {
248
  /* don't bother sorting an array of size <= 1 */
249
175k
  if (size <= 1) {
250
0
    return;
251
0
  }
252
253
175k
  BINARY_INSERTION_SORT_START(dst, 1, size);
254
175k
}
255
256
/* timsort implementation, based on timsort.txt */
257
258
3.09k
static __inline void REVERSE_ELEMENTS(SORT_TYPE *dst, size_t start, size_t end) {
259
6.43k
  while (1) {
260
6.43k
    if (start >= end) {
261
3.09k
      return;
262
3.09k
    }
263
264
3.33k
    SORT_SWAP(dst[start], dst[end]);
265
3.33k
    start++;
266
3.33k
    end--;
267
3.33k
  }
268
3.09k
}
269
270
27.1k
static size_t COUNT_RUN(SORT_TYPE *dst, const size_t start, const size_t size) {
271
27.1k
  size_t curr;
272
273
27.1k
  if (size - start == 1) {
274
7.15k
    return 1;
275
7.15k
  }
276
277
19.9k
  if (start >= size - 2) {
278
113
    if (SORT_CMP(dst[size - 2], dst[size - 1]) > 0) {
279
0
      SORT_SWAP(dst[size - 2], dst[size - 1]);
280
0
    }
281
282
113
    return 2;
283
113
  }
284
285
19.8k
  curr = start + 2;
286
287
19.8k
  if (SORT_CMP(dst[start], dst[start + 1]) <= 0) {
288
    /* increasing run */
289
1.97M
    while (1) {
290
1.97M
      if (curr == size - 1) {
291
8.91k
        break;
292
8.91k
      }
293
294
1.96M
      if (SORT_CMP(dst[curr - 1], dst[curr]) > 0) {
295
7.82k
        break;
296
7.82k
      }
297
298
1.95M
      curr++;
299
1.95M
    }
300
301
16.7k
    return curr - start;
302
16.7k
  } else {
303
    /* decreasing run */
304
3.79k
    while (1) {
305
3.79k
      if (curr == size - 1) {
306
7
        break;
307
7
      }
308
309
3.78k
      if (SORT_CMP(dst[curr - 1], dst[curr]) <= 0) {
310
3.09k
        break;
311
3.09k
      }
312
313
696
      curr++;
314
696
    }
315
316
    /* reverse in-place */
317
3.09k
    REVERSE_ELEMENTS(dst, start, curr - 1);
318
3.09k
    return curr - start;
319
3.09k
  }
320
19.8k
}
321
322
7.89k
static int CHECK_INVARIANT(TIM_SORT_RUN_T *stack, const int stack_curr) {
323
7.89k
  size_t A, B, C;
324
325
7.89k
  if (stack_curr < 2) {
326
2.02k
    return 1;
327
2.02k
  }
328
329
5.87k
  if (stack_curr == 2) {
330
1.74k
    const size_t A1 = stack[stack_curr - 2].length;
331
1.74k
    const size_t B1 = stack[stack_curr - 1].length;
332
333
1.74k
    if (A1 <= B1) {
334
93
      return 0;
335
93
    }
336
337
1.65k
    return 1;
338
1.74k
  }
339
340
4.13k
  A = stack[stack_curr - 3].length;
341
4.13k
  B = stack[stack_curr - 2].length;
342
4.13k
  C = stack[stack_curr - 1].length;
343
344
4.13k
  if ((A <= B + C) || (B <= C)) {
345
3.33k
    return 0;
346
3.33k
  }
347
348
797
  return 1;
349
4.13k
}
350
351
typedef struct {
352
  size_t alloc;
353
  SORT_TYPE *storage;
354
} TEMP_STORAGE_T;
355
356
17.1k
static void TIM_SORT_RESIZE(TEMP_STORAGE_T *store, const size_t new_size) {
357
17.1k
  if (store->alloc < new_size) {
358
12.3k
    SORT_TYPE *tempstore = (SORT_TYPE *)realloc(store->storage, new_size * sizeof(SORT_TYPE));
359
360
12.3k
    if (tempstore == NULL) {
361
0
      fprintf(stderr, "Error allocating temporary storage for tim sort: need %lu bytes",
362
0
              (unsigned long)(sizeof(SORT_TYPE) * new_size));
363
0
      exit(1);
364
0
    }
365
366
12.3k
    store->storage = tempstore;
367
12.3k
    store->alloc = new_size;
368
12.3k
  }
369
17.1k
}
370
371
static void TIM_SORT_MERGE(SORT_TYPE *dst, const TIM_SORT_RUN_T *stack, const int stack_curr,
372
17.1k
                           TEMP_STORAGE_T *store) {
373
17.1k
  const size_t A = stack[stack_curr - 2].length;
374
17.1k
  const size_t B = stack[stack_curr - 1].length;
375
17.1k
  const size_t curr = stack[stack_curr - 2].start;
376
17.1k
  SORT_TYPE *storage;
377
17.1k
  size_t i, j, k;
378
17.1k
  TIM_SORT_RESIZE(store, MIN(A, B));
379
17.1k
  storage = store->storage;
380
381
  /* left merge */
382
17.1k
  if (A < B) {
383
5.13k
    memcpy(storage, &dst[curr], A * sizeof(SORT_TYPE));
384
5.13k
    i = 0;
385
5.13k
    j = curr + A;
386
387
596k
    for (k = curr; k < curr + A + B; k++) {
388
594k
      if ((i < A) && (j < curr + A + B)) {
389
584k
        if (SORT_CMP(storage[i], dst[j]) <= 0) {
390
290k
          dst[k] = storage[i++];
391
293k
        } else {
392
293k
          dst[k] = dst[j++];
393
293k
        }
394
584k
      } else if (i < A) {
395
6.75k
        dst[k] = storage[i++];
396
6.75k
      } else {
397
3.80k
        break;
398
3.80k
      }
399
594k
    }
400
12.0k
  } else {
401
    /* right merge */
402
12.0k
    memcpy(storage, &dst[curr + A], B * sizeof(SORT_TYPE));
403
12.0k
    i = B;
404
12.0k
    j = curr + A;
405
12.0k
    k = curr + A + B;
406
407
393k
    while (k > curr) {
408
393k
      k--;
409
393k
      if ((i > 0) && (j > curr)) {
410
374k
        if (SORT_CMP(dst[j - 1], storage[i - 1]) > 0) {
411
105k
          dst[k] = dst[--j];
412
268k
        } else {
413
268k
          dst[k] = storage[--i];
414
268k
        }
415
374k
      } else if (i > 0) {
416
7.64k
        dst[k] = storage[--i];
417
11.4k
      } else {
418
11.4k
        break;
419
11.4k
      }
420
393k
    }
421
12.0k
  }
422
17.1k
}
423
424
static int TIM_SORT_COLLAPSE(SORT_TYPE *dst, TIM_SORT_RUN_T *stack, int stack_curr,
425
3.42k
                             TEMP_STORAGE_T *store, const size_t size) {
426
7.16k
  while (1) {
427
7.16k
    size_t A, B, C, D;
428
7.16k
    int ABC, BCD, CD;
429
430
    /* if the stack only has one thing on it, we are done with the collapse */
431
7.16k
    if (stack_curr <= 1) {
432
0
      break;
433
0
    }
434
435
    /* if this is the last merge, just do it */
436
7.16k
    if ((stack_curr == 2) && (stack[0].length + stack[1].length == size)) {
437
0
      TIM_SORT_MERGE(dst, stack, stack_curr, store);
438
0
      stack[0].length += stack[1].length;
439
0
      stack_curr--;
440
0
      break;
441
0
    }
442
    /* check if the invariant is off for a stack of 2 elements */
443
7.16k
    else if ((stack_curr == 2) && (stack[0].length <= stack[1].length)) {
444
2.02k
      TIM_SORT_MERGE(dst, stack, stack_curr, store);
445
2.02k
      stack[0].length += stack[1].length;
446
2.02k
      stack_curr--;
447
2.02k
      break;
448
5.14k
    } else if (stack_curr == 2) {
449
1.15k
      break;
450
1.15k
    }
451
452
3.99k
    B = stack[stack_curr - 3].length;
453
3.99k
    C = stack[stack_curr - 2].length;
454
3.99k
    D = stack[stack_curr - 1].length;
455
456
3.99k
    if (stack_curr >= 4) {
457
729
      A = stack[stack_curr - 4].length;
458
729
      ABC = (A <= B + C);
459
3.26k
    } else {
460
3.26k
      ABC = 0;
461
3.26k
    }
462
463
3.99k
    BCD = (B <= C + D) || ABC;
464
3.99k
    CD = (C <= D);
465
466
    /* Both invariants are good */
467
3.99k
    if (!BCD && !CD) {
468
257
      break;
469
257
    }
470
471
    /* left merge */
472
3.73k
    if (BCD && !CD) {
473
801
      TIM_SORT_MERGE(dst, stack, stack_curr - 1, store);
474
801
      stack[stack_curr - 3].length += stack[stack_curr - 2].length;
475
801
      stack[stack_curr - 2] = stack[stack_curr - 1];
476
801
      stack_curr--;
477
2.93k
    } else {
478
      /* right merge */
479
2.93k
      TIM_SORT_MERGE(dst, stack, stack_curr, store);
480
2.93k
      stack[stack_curr - 2].length += stack[stack_curr - 1].length;
481
2.93k
      stack_curr--;
482
2.93k
    }
483
3.73k
  }
484
485
3.42k
  return stack_curr;
486
3.42k
}
487
488
static __inline int PUSH_NEXT(SORT_TYPE *dst,
489
                              const size_t size,
490
                              TEMP_STORAGE_T *store,
491
                              const size_t minrun,
492
                              TIM_SORT_RUN_T *run_stack,
493
                              size_t *stack_curr,
494
27.1k
                              size_t *curr) {
495
27.1k
  size_t len = COUNT_RUN(dst, *curr, size);
496
27.1k
  size_t run = minrun;
497
498
27.1k
  if (run > size - *curr) {
499
8.78k
    run = size - *curr;
500
8.78k
  }
501
502
27.1k
  if (run > len) {
503
9.55k
    BINARY_INSERTION_SORT_START(&dst[*curr], len, run);
504
9.55k
    len = run;
505
9.55k
  }
506
507
27.1k
  run_stack[*stack_curr].start = *curr;
508
27.1k
  run_stack[*stack_curr].length = len;
509
27.1k
  (*stack_curr)++;
510
27.1k
  *curr += len;
511
512
27.1k
  if (*curr == size) {
513
    /* finish up */
514
21.3k
    while (*stack_curr > 1) {
515
11.4k
      TIM_SORT_MERGE(dst, run_stack, *stack_curr, store);
516
11.4k
      run_stack[*stack_curr - 2].length += run_stack[*stack_curr - 1].length;
517
11.4k
      (*stack_curr)--;
518
11.4k
    }
519
520
9.91k
    if (store->storage != NULL) {
521
9.91k
      free(store->storage);
522
9.91k
      store->storage = NULL;
523
9.91k
    }
524
525
9.91k
    return 0;
526
9.91k
  }
527
528
17.1k
  return 1;
529
27.1k
}
530
531
475k
void TIM_SORT(SORT_TYPE *dst, const size_t size) {
532
475k
  size_t minrun;
533
475k
  TEMP_STORAGE_T _store, *store;
534
475k
  TIM_SORT_RUN_T run_stack[TIM_SORT_STACK_SIZE];
535
475k
  size_t stack_curr = 0;
536
475k
  size_t curr = 0;
537
538
  /* don't bother sorting an array of size 1 */
539
475k
  if (size <= 1) {
540
290k
    return;
541
290k
  }
542
543
185k
  if (size < 64) {
544
175k
    BINARY_INSERTION_SORT(dst, size);
545
175k
    return;
546
175k
  }
547
548
  /* compute the minimum run length */
549
9.91k
  minrun = compute_minrun(size);
550
  /* temporary storage for merges */
551
9.91k
  store = &_store;
552
9.91k
  store->alloc = 0;
553
9.91k
  store->storage = NULL;
554
555
9.91k
  if (!PUSH_NEXT(dst, size, store, minrun, run_stack, &stack_curr, &curr)) {
556
0
    return;
557
0
  }
558
559
9.91k
  if (!PUSH_NEXT(dst, size, store, minrun, run_stack, &stack_curr, &curr)) {
560
7.11k
    return;
561
7.11k
  }
562
563
2.80k
  if (!PUSH_NEXT(dst, size, store, minrun, run_stack, &stack_curr, &curr)) {
564
782
    return;
565
782
  }
566
567
7.89k
  while (1) {
568
7.89k
    if (!CHECK_INVARIANT(run_stack, stack_curr)) {
569
3.42k
      stack_curr = TIM_SORT_COLLAPSE(dst, run_stack, stack_curr, store, size);
570
3.42k
      continue;
571
3.42k
    }
572
573
4.46k
    if (!PUSH_NEXT(dst, size, store, minrun, run_stack, &stack_curr, &curr)) {
574
2.01k
      return;
575
2.01k
    }
576
4.46k
  }
577
2.01k
}
578
579
#undef SORT_CONCAT
580
#undef SORT_MAKE_STR1
581
#undef SORT_MAKE_STR
582
#undef SORT_NAME
583
#undef SORT_TYPE
584
#undef SORT_CMP
585
#undef TEMP_STORAGE_T
586
#undef TIM_SORT_RUN_T
587
#undef PUSH_NEXT
588
#undef SORT_SWAP
589
#undef SORT_CONCAT
590
#undef SORT_MAKE_STR1
591
#undef SORT_MAKE_STR
592
#undef BINARY_INSERTION_FIND
593
#undef BINARY_INSERTION_SORT_START
594
#undef BINARY_INSERTION_SORT
595
#undef REVERSE_ELEMENTS
596
#undef COUNT_RUN
597
#undef TIM_SORT
598
#undef TIM_SORT_RESIZE
599
#undef TIM_SORT_COLLAPSE
600
#undef TIM_SORT_RUN_T
601
#undef TEMP_STORAGE_T