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c90cfc225b
Use MINSTD to generate pseudo-random numbers consistently instead of using rand(3), whose output can vary from system to system, and reset its seed before filling in the test values. This gives repeatable results across versions and systems, which simplifies sharing and comparing of results between developers. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
412 lines
8.3 KiB
C
412 lines
8.3 KiB
C
#include "test-tool.h"
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#include "cache.h"
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#include "mergesort.h"
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static uint32_t minstd_rand(uint32_t *state)
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{
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*state = (uint64_t)*state * 48271 % 2147483647;
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return *state;
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}
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struct line {
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char *text;
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struct line *next;
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};
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static void *get_next(const void *a)
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{
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return ((const struct line *)a)->next;
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}
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static void set_next(void *a, void *b)
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{
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((struct line *)a)->next = b;
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}
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static int compare_strings(const void *a, const void *b)
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{
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const struct line *x = a, *y = b;
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return strcmp(x->text, y->text);
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}
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static int sort_stdin(void)
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{
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struct line *line, *p = NULL, *lines = NULL;
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struct strbuf sb = STRBUF_INIT;
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while (!strbuf_getline(&sb, stdin)) {
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line = xmalloc(sizeof(struct line));
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line->text = strbuf_detach(&sb, NULL);
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if (p) {
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line->next = p->next;
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p->next = line;
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} else {
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line->next = NULL;
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lines = line;
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}
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p = line;
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}
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lines = llist_mergesort(lines, get_next, set_next, compare_strings);
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while (lines) {
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puts(lines->text);
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lines = lines->next;
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}
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return 0;
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}
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static void dist_sawtooth(int *arr, int n, int m)
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{
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int i;
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for (i = 0; i < n; i++)
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arr[i] = i % m;
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}
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static void dist_rand(int *arr, int n, int m)
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{
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int i;
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uint32_t seed = 1;
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for (i = 0; i < n; i++)
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arr[i] = minstd_rand(&seed) % m;
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}
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static void dist_stagger(int *arr, int n, int m)
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{
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int i;
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for (i = 0; i < n; i++)
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arr[i] = (i * m + i) % n;
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}
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static void dist_plateau(int *arr, int n, int m)
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{
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int i;
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for (i = 0; i < n; i++)
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arr[i] = (i < m) ? i : m;
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}
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static void dist_shuffle(int *arr, int n, int m)
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{
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int i, j, k;
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uint32_t seed = 1;
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for (i = j = 0, k = 1; i < n; i++)
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arr[i] = minstd_rand(&seed) % m ? (j += 2) : (k += 2);
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}
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#define DIST(name) { #name, dist_##name }
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static struct dist {
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const char *name;
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void (*fn)(int *arr, int n, int m);
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} dist[] = {
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DIST(sawtooth),
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DIST(rand),
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DIST(stagger),
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DIST(plateau),
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DIST(shuffle),
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};
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static const struct dist *get_dist_by_name(const char *name)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(dist); i++) {
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if (!strcmp(dist[i].name, name))
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return &dist[i];
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}
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return NULL;
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}
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static void mode_copy(int *arr, int n)
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{
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/* nothing */
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}
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static void mode_reverse(int *arr, int n)
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{
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int i, j;
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for (i = 0, j = n - 1; i < j; i++, j--)
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SWAP(arr[i], arr[j]);
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}
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static void mode_reverse_1st_half(int *arr, int n)
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{
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mode_reverse(arr, n / 2);
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}
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static void mode_reverse_2nd_half(int *arr, int n)
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{
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int half = n / 2;
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mode_reverse(arr + half, n - half);
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}
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static int compare_ints(const void *av, const void *bv)
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{
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const int *ap = av, *bp = bv;
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int a = *ap, b = *bp;
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return (a > b) - (a < b);
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}
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static void mode_sort(int *arr, int n)
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{
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QSORT(arr, n, compare_ints);
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}
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static void mode_dither(int *arr, int n)
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{
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int i;
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for (i = 0; i < n; i++)
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arr[i] += i % 5;
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}
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static void unriffle(int *arr, int n, int *tmp)
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{
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int i, j;
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COPY_ARRAY(tmp, arr, n);
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for (i = j = 0; i < n; i += 2)
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arr[j++] = tmp[i];
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for (i = 1; i < n; i += 2)
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arr[j++] = tmp[i];
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}
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static void unriffle_recursively(int *arr, int n, int *tmp)
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{
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if (n > 1) {
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int half = n / 2;
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unriffle(arr, n, tmp);
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unriffle_recursively(arr, half, tmp);
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unriffle_recursively(arr + half, n - half, tmp);
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}
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}
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static void mode_unriffle(int *arr, int n)
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{
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int *tmp;
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ALLOC_ARRAY(tmp, n);
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unriffle_recursively(arr, n, tmp);
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free(tmp);
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}
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static unsigned int prev_pow2(unsigned int n)
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{
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unsigned int pow2 = 1;
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while (pow2 * 2 < n)
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pow2 *= 2;
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return pow2;
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}
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static void unriffle_recursively_skewed(int *arr, int n, int *tmp)
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{
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if (n > 1) {
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int pow2 = prev_pow2(n);
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int rest = n - pow2;
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unriffle(arr + pow2 - rest, rest * 2, tmp);
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unriffle_recursively_skewed(arr, pow2, tmp);
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unriffle_recursively_skewed(arr + pow2, rest, tmp);
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}
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}
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static void mode_unriffle_skewed(int *arr, int n)
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{
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int *tmp;
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ALLOC_ARRAY(tmp, n);
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unriffle_recursively_skewed(arr, n, tmp);
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free(tmp);
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}
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#define MODE(name) { #name, mode_##name }
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static struct mode {
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const char *name;
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void (*fn)(int *arr, int n);
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} mode[] = {
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MODE(copy),
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MODE(reverse),
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MODE(reverse_1st_half),
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MODE(reverse_2nd_half),
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MODE(sort),
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MODE(dither),
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MODE(unriffle),
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MODE(unriffle_skewed),
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};
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static const struct mode *get_mode_by_name(const char *name)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(mode); i++) {
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if (!strcmp(mode[i].name, name))
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return &mode[i];
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}
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return NULL;
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}
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static int generate(int argc, const char **argv)
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{
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const struct dist *dist = NULL;
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const struct mode *mode = NULL;
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int i, n, m, *arr;
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if (argc != 4)
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return 1;
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dist = get_dist_by_name(argv[0]);
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mode = get_mode_by_name(argv[1]);
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n = strtol(argv[2], NULL, 10);
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m = strtol(argv[3], NULL, 10);
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if (!dist || !mode)
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return 1;
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ALLOC_ARRAY(arr, n);
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dist->fn(arr, n, m);
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mode->fn(arr, n);
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for (i = 0; i < n; i++)
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printf("%08x\n", arr[i]);
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free(arr);
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return 0;
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}
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static struct stats {
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int get_next, set_next, compare;
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} stats;
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struct number {
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int value, rank;
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struct number *next;
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};
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static void *get_next_number(const void *a)
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{
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stats.get_next++;
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return ((const struct number *)a)->next;
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}
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static void set_next_number(void *a, void *b)
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{
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stats.set_next++;
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((struct number *)a)->next = b;
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}
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static int compare_numbers(const void *av, const void *bv)
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{
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const struct number *an = av, *bn = bv;
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int a = an->value, b = bn->value;
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stats.compare++;
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return (a > b) - (a < b);
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}
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static void clear_numbers(struct number *list)
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{
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while (list) {
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struct number *next = list->next;
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free(list);
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list = next;
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}
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}
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static int test(const struct dist *dist, const struct mode *mode, int n, int m)
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{
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int *arr;
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size_t i;
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struct number *curr, *list, **tail;
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int is_sorted = 1;
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int is_stable = 1;
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const char *verdict;
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int result = -1;
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ALLOC_ARRAY(arr, n);
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dist->fn(arr, n, m);
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mode->fn(arr, n);
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for (i = 0, tail = &list; i < n; i++) {
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curr = xmalloc(sizeof(*curr));
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curr->value = arr[i];
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curr->rank = i;
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*tail = curr;
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tail = &curr->next;
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}
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*tail = NULL;
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stats.get_next = stats.set_next = stats.compare = 0;
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list = llist_mergesort(list, get_next_number, set_next_number,
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compare_numbers);
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QSORT(arr, n, compare_ints);
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for (i = 0, curr = list; i < n && curr; i++, curr = curr->next) {
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if (arr[i] != curr->value)
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is_sorted = 0;
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if (curr->next && curr->value == curr->next->value &&
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curr->rank >= curr->next->rank)
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is_stable = 0;
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}
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if (i < n) {
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verdict = "too short";
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} else if (curr) {
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verdict = "too long";
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} else if (!is_sorted) {
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verdict = "not sorted";
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} else if (!is_stable) {
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verdict = "unstable";
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} else {
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verdict = "OK";
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result = 0;
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}
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printf("%-9s %-16s %8d %8d %8d %8d %8d %s\n",
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dist->name, mode->name, n, m, stats.get_next, stats.set_next,
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stats.compare, verdict);
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clear_numbers(list);
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free(arr);
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return result;
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}
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/*
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* A version of the qsort certification program from "Engineering a Sort
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* Function" by Bentley and McIlroy, Software—Practice and Experience,
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* Volume 23, Issue 11, 1249–1265 (November 1993).
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*/
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static int run_tests(int argc, const char **argv)
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{
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const char *argv_default[] = { "100", "1023", "1024", "1025" };
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if (!argc)
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return run_tests(ARRAY_SIZE(argv_default), argv_default);
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printf("%-9s %-16s %8s %8s %8s %8s %8s %s\n",
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"distribut", "mode", "n", "m", "get_next", "set_next",
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"compare", "verdict");
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while (argc--) {
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int i, j, m, n = strtol(*argv++, NULL, 10);
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for (i = 0; i < ARRAY_SIZE(dist); i++) {
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for (j = 0; j < ARRAY_SIZE(mode); j++) {
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for (m = 1; m < 2 * n; m *= 2) {
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if (test(&dist[i], &mode[j], n, m))
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return 1;
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}
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}
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}
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}
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return 0;
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}
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int cmd__mergesort(int argc, const char **argv)
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{
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int i;
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const char *sep;
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if (argc == 6 && !strcmp(argv[1], "generate"))
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return generate(argc - 2, argv + 2);
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if (argc == 2 && !strcmp(argv[1], "sort"))
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return sort_stdin();
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if (argc > 1 && !strcmp(argv[1], "test"))
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return run_tests(argc - 2, argv + 2);
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fprintf(stderr, "usage: test-tool mergesort generate <distribution> <mode> <n> <m>\n");
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fprintf(stderr, " or: test-tool mergesort sort\n");
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fprintf(stderr, " or: test-tool mergesort test [<n>...]\n");
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fprintf(stderr, "\n");
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for (i = 0, sep = "distributions: "; i < ARRAY_SIZE(dist); i++, sep = ", ")
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fprintf(stderr, "%s%s", sep, dist[i].name);
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fprintf(stderr, "\n");
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for (i = 0, sep = "modes: "; i < ARRAY_SIZE(mode); i++, sep = ", ")
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fprintf(stderr, "%s%s", sep, mode[i].name);
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fprintf(stderr, "\n");
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return 129;
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}
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