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Import musl qsort as the Sortix one turned out to use a buggy algorithm.
This commit is contained in:
Jonas 'Sortie' Termansen
parent
2e03bd94d3
commit
5351bd0719
1 changed files with 238 additions and 21 deletions
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@ -1,35 +1,252 @@
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/*
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* Copyright (c) 2012, 2014 Jonas 'Sortie' Termansen.
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/* Copyright (C) 2011 by Valentin Ochs
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to
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* deal in the Software without restriction, including without limitation the
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* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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* sell copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* stdlib/qsort.c
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* Sort an array.
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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/* Minor changes by Rich Felker for integration in musl, 2011-04-27. */
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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static int compare_wrapper(const void* a, const void* b, void* arg)
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#ifndef a_ctz_64
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#define a_ctz_64 a_ctz_64
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static inline int a_ctz_64(uint64_t x)
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{
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return ((int (*)(const void*, const void*)) arg)(a, b);
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static const char debruijn64[64] = {
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0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28,
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62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11,
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63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10,
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51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12
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};
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static const char debruijn32[32] = {
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0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13,
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31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14
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};
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if (sizeof(long) < 8) {
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uint32_t y = x;
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if (!y) {
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y = x>>32;
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return 32 + debruijn32[(y&-y)*0x076be629 >> 27];
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}
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return debruijn32[(y&-y)*0x076be629 >> 27];
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}
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return debruijn64[(x&-x)*0x022fdd63cc95386dull >> 58];
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}
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#endif
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#ifndef a_ctz_l
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#define a_ctz_l a_ctz_l
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static inline int a_ctz_l(unsigned long x)
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{
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static const char debruijn32[32] = {
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0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13,
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31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14
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};
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if (sizeof(long) == 8) return a_ctz_64(x);
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return debruijn32[(x&-x)*0x076be629 >> 27];
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}
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#endif
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#define ntz(x) a_ctz_l((x))
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typedef int (*cmpfun)(const void *, const void *);
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static inline int pntz(size_t p[2]) {
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int r = ntz(p[0] - 1);
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if(r != 0 || (r = 8*sizeof(size_t) + ntz(p[1])) != 8*sizeof(size_t)) {
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return r;
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}
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return 0;
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}
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void qsort(void* base_ptr,
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size_t num_elements,
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size_t element_size,
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int (*compare)(const void*, const void*))
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static void cycle(size_t width, unsigned char* ar[], int n)
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{
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qsort_r(base_ptr, num_elements, element_size, compare_wrapper, (void*) compare);
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unsigned char tmp[256];
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size_t l;
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int i;
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if(n < 2) {
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return;
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}
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ar[n] = tmp;
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while(width) {
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l = sizeof(tmp) < width ? sizeof(tmp) : width;
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memcpy(ar[n], ar[0], l);
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for(i = 0; i < n; i++) {
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memcpy(ar[i], ar[i + 1], l);
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ar[i] += l;
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}
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width -= l;
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}
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}
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/* shl() and shr() need n > 0 */
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static inline void shl(size_t p[2], int n)
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{
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if(n >= 8 * sizeof(size_t)) {
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n -= 8 * sizeof(size_t);
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p[1] = p[0];
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p[0] = 0;
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}
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p[1] <<= n;
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p[1] |= p[0] >> (sizeof(size_t) * 8 - n);
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p[0] <<= n;
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}
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static inline void shr(size_t p[2], int n)
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{
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if(n >= 8 * sizeof(size_t)) {
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n -= 8 * sizeof(size_t);
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p[0] = p[1];
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p[1] = 0;
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}
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p[0] >>= n;
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p[0] |= p[1] << (sizeof(size_t) * 8 - n);
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p[1] >>= n;
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}
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static void sift(unsigned char *head, size_t width, cmpfun cmp, int pshift, size_t lp[])
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{
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unsigned char *rt, *lf;
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unsigned char *ar[14 * sizeof(size_t) + 1];
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int i = 1;
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ar[0] = head;
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while(pshift > 1) {
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rt = head - width;
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lf = head - width - lp[pshift - 2];
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if((*cmp)(ar[0], lf) >= 0 && (*cmp)(ar[0], rt) >= 0) {
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break;
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}
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if((*cmp)(lf, rt) >= 0) {
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ar[i++] = lf;
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head = lf;
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pshift -= 1;
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} else {
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ar[i++] = rt;
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head = rt;
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pshift -= 2;
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}
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}
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cycle(width, ar, i);
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}
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static void trinkle(unsigned char *head, size_t width, cmpfun cmp, size_t pp[2], int pshift, int trusty, size_t lp[])
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{
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unsigned char *stepson,
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*rt, *lf;
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size_t p[2];
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unsigned char *ar[14 * sizeof(size_t) + 1];
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int i = 1;
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int trail;
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p[0] = pp[0];
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p[1] = pp[1];
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ar[0] = head;
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while(p[0] != 1 || p[1] != 0) {
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stepson = head - lp[pshift];
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if((*cmp)(stepson, ar[0]) <= 0) {
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break;
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}
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if(!trusty && pshift > 1) {
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rt = head - width;
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lf = head - width - lp[pshift - 2];
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if((*cmp)(rt, stepson) >= 0 || (*cmp)(lf, stepson) >= 0) {
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break;
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}
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}
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ar[i++] = stepson;
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head = stepson;
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trail = pntz(p);
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shr(p, trail);
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pshift += trail;
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trusty = 0;
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}
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if(!trusty) {
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cycle(width, ar, i);
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sift(head, width, cmp, pshift, lp);
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}
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}
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void qsort(void *base, size_t nel, size_t width, cmpfun cmp)
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{
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size_t lp[12*sizeof(size_t)];
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size_t i, size = width * nel;
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unsigned char *head, *high;
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size_t p[2] = {1, 0};
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int pshift = 1;
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int trail;
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if (!size) return;
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head = base;
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high = head + size - width;
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/* Precompute Leonardo numbers, scaled by element width */
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for(lp[0]=lp[1]=width, i=2; (lp[i]=lp[i-2]+lp[i-1]+width) < size; i++);
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while(head < high) {
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if((p[0] & 3) == 3) {
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sift(head, width, cmp, pshift, lp);
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shr(p, 2);
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pshift += 2;
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} else {
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if(lp[pshift - 1] >= high - head) {
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trinkle(head, width, cmp, p, pshift, 0, lp);
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} else {
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sift(head, width, cmp, pshift, lp);
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}
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if(pshift == 1) {
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shl(p, 1);
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pshift = 0;
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} else {
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shl(p, pshift - 1);
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pshift = 1;
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}
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}
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p[0] |= 1;
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head += width;
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}
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trinkle(head, width, cmp, p, pshift, 0, lp);
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while(pshift != 1 || p[0] != 1 || p[1] != 0) {
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if(pshift <= 1) {
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trail = pntz(p);
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shr(p, trail);
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pshift += trail;
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} else {
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shl(p, 2);
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pshift -= 2;
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p[0] ^= 7;
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shr(p, 1);
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trinkle(head - lp[pshift] - width, width, cmp, p, pshift + 1, 1, lp);
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shl(p, 1);
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p[0] |= 1;
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trinkle(head - width, width, cmp, p, pshift, 1, lp);
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}
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head -= width;
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}
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}
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