8bef79bf3c
These don't need to be in common.h so move them out into a new header. Also add some missing comments. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Tom Rini <trini@konsulko.com>
142 lines
3.1 KiB
C
142 lines
3.1 KiB
C
// SPDX-License-Identifier: BSD-3-Clause
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/*
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*/
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#include "yportenv.h"
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#include <sort.h>
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/* #include <linux/string.h> */
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/*
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* Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
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*/
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#define swapcode(TYPE, parmi, parmj, n) do { \
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long i = (n) / sizeof(TYPE); \
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register TYPE *pi = (TYPE *) (parmi); \
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register TYPE *pj = (TYPE *) (parmj); \
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do { \
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register TYPE t = *pi; \
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*pi++ = *pj; \
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*pj++ = t; \
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} while (--i > 0); \
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} while (0)
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#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
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es % sizeof(long) ? 2 : es == sizeof(long) ? 0 : 1;
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static inline void
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swapfunc(char *a, char *b, int n, int swaptype)
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{
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if (swaptype <= 1)
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swapcode(long, a, b, n);
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else
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swapcode(char, a, b, n);
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}
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#define yswap(a, b) do { \
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if (swaptype == 0) { \
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long t = *(long *)(a); \
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*(long *)(a) = *(long *)(b); \
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*(long *)(b) = t; \
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} else \
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swapfunc(a, b, es, swaptype); \
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} while (0)
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#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
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static inline char *
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med3(char *a, char *b, char *c, int (*cmp)(const void *, const void *))
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{
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return cmp(a, b) < 0 ?
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(cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a))
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: (cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c));
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}
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#ifndef min
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#define min(a, b) (((a) < (b)) ? (a) : (b))
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#endif
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void
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yaffs_qsort(void *aa, size_t n, size_t es,
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int (*cmp)(const void *, const void *))
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{
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char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
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int d, r, swaptype, swap_cnt;
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register char *a = aa;
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loop: SWAPINIT(a, es);
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swap_cnt = 0;
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if (n < 7) {
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for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es)
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for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
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pl -= es)
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yswap(pl, pl - es);
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return;
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}
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pm = (char *)a + (n / 2) * es;
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if (n > 7) {
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pl = (char *)a;
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pn = (char *)a + (n - 1) * es;
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if (n > 40) {
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d = (n / 8) * es;
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pl = med3(pl, pl + d, pl + 2 * d, cmp);
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pm = med3(pm - d, pm, pm + d, cmp);
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pn = med3(pn - 2 * d, pn - d, pn, cmp);
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}
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pm = med3(pl, pm, pn, cmp);
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}
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yswap(a, pm);
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pa = pb = (char *)a + es;
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pc = pd = (char *)a + (n - 1) * es;
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for (;;) {
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while (pb <= pc && (r = cmp(pb, a)) <= 0) {
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if (r == 0) {
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swap_cnt = 1;
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yswap(pa, pb);
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pa += es;
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}
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pb += es;
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}
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while (pb <= pc && (r = cmp(pc, a)) >= 0) {
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if (r == 0) {
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swap_cnt = 1;
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yswap(pc, pd);
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pd -= es;
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}
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pc -= es;
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}
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if (pb > pc)
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break;
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yswap(pb, pc);
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swap_cnt = 1;
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pb += es;
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pc -= es;
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}
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if (swap_cnt == 0) { /* Switch to insertion sort */
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for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
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for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
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pl -= es)
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yswap(pl, pl - es);
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return;
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}
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pn = (char *)a + n * es;
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r = min(pa - (char *)a, pb - pa);
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vecswap(a, pb - r, r);
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r = min((long)(pd - pc), (long)(pn - pd - es));
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vecswap(pb, pn - r, r);
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r = pb - pa;
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if (r > es)
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yaffs_qsort(a, r / es, es, cmp);
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r = pd - pc;
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if (r > es) {
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/* Iterate rather than recurse to save stack space */
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a = pn - r;
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n = r / es;
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goto loop;
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}
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/* yaffs_qsort(pn - r, r / es, es, cmp);*/
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}
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