2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
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31 #if defined(LIBC_SCCS) && !defined(lint)
32 static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93";
33 #endif /* LIBC_SCCS and not lint */
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
47 typedef int cmp_t(void *, const void *, const void *);
49 typedef int cmp_t(const void *, const void *);
51 static inline char *med3(char *, char *, char *, cmp_t *, void *);
52 static inline void swapfunc(char *, char *, int, int);
55 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
57 #define swapcode(TYPE, parmi, parmj, n) { \
58 long i = (n) / sizeof (TYPE); \
59 TYPE *pi = (TYPE *) (parmi); \
60 TYPE *pj = (TYPE *) (parmj); \
68 #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
69 es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
72 swapfunc(a, b, n, swaptype)
77 swapcode(long, a, b, n)
79 swapcode(char, a, b, n)
83 if (swaptype == 0) { \
84 long t = *(long *)(a); \
85 *(long *)(a) = *(long *)(b); \
88 swapfunc(a, b, es, swaptype)
90 #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
93 #define CMP(t, x, y) (cmp((t), (x), (y)))
95 #define CMP(t, x, y) (cmp((x), (y)))
99 med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk
105 return CMP(thunk, a, b) < 0 ?
106 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a ))
107 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));
112 rk_qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
116 rk_qsort(void *a, size_t n, size_t es, cmp_t *cmp)
119 char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
122 int swaptype, swap_cnt;
124 loop: SWAPINIT(a, es);
127 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
129 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
134 pm = (char *)a + (n / 2) * es;
137 pn = (char *)a + (n - 1) * es;
140 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);
141 pm = med3(pm - d, pm, pm + d, cmp, thunk);
142 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk);
144 pm = med3(pl, pm, pn, cmp, thunk);
147 pa = pb = (char *)a + es;
149 pc = pd = (char *)a + (n - 1) * es;
151 while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) {
152 if (cmp_result == 0) {
159 while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) {
160 if (cmp_result == 0) {
174 if (swap_cnt == 0) { /* Switch to insertion sort */
175 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
177 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
183 pn = (char *)a + n * es;
184 r = min(pa - (char *)a, pb - pa);
185 vecswap(a, pb - r, r);
186 r = min(pd - pc, pn - pd - es);
187 vecswap(pb, pn - r, r);
188 if ((r = pb - pa) > es)
190 rk_qsort_r(a, r / es, es, thunk, cmp);
192 rk_qsort(a, r / es, es, cmp);
194 if ((r = pd - pc) > es) {
195 /* Iterate rather than recurse to save stack space */
200 /* rk_qsort(pn - r, r / es, es, cmp);*/
203 #endif /* NEED_QSORT */