2 * Modifications from vanilla NetBSD source:
3 * Add do ... while() macro fix
4 * Remove __inline, _DIAGASSERTs, __P
6 * $PostgreSQL: pgsql/src/port/qsort.c,v 1.8 2005/10/15 02:49:51 momjian Exp $
9 /* $NetBSD: qsort.c,v 1.13 2003/08/07 16:43:42 agc Exp $ */
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43 static char *med3(char *, char *, char *,
44 int (*) (const void *, const void *));
45 static void swapfunc(char *, char *, size_t, int);
47 #define min(a, b) ((a) < (b) ? (a) : (b))
50 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
52 #define swapcode(TYPE, parmi, parmj, n) \
54 size_t i = (n) / sizeof (TYPE); \
55 TYPE *pi = (TYPE *)(void *)(parmi); \
56 TYPE *pj = (TYPE *)(void *)(parmj); \
64 #define SWAPINIT(a, es) swaptype = ((char *)(a) - (char *)0) % sizeof(long) || \
65 (es) % sizeof(long) ? 2 : (es) == sizeof(long)? 0 : 1;
68 swapfunc(a, b, n, swaptype)
75 swapcode(long, a, b, n);
77 swapcode(char, a, b, n);
81 if (swaptype == 0) { \
82 long t = *(long *)(void *)(a); \
83 *(long *)(void *)(a) = *(long *)(void *)(b); \
84 *(long *)(void *)(b) = t; \
86 swapfunc(a, b, es, swaptype)
88 #define vecswap(a, b, n) if ((n) > 0) swapfunc((a), (b), (size_t)(n), swaptype)
95 int (*cmp) (const void *, const void *);
97 return cmp(a, b) < 0 ?
98 (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a))
99 : (cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c));
107 int (*cmp) (const void *, const void *);
121 loop:SWAPINIT(a, es);
125 for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
126 for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
131 pm = (char *) a + (n / 2) * es;
135 pn = (char *) a + (n - 1) * es;
139 pl = med3(pl, pl + d, pl + 2 * d, cmp);
140 pm = med3(pm - d, pm, pm + d, cmp);
141 pn = med3(pn - 2 * d, pn - d, pn, cmp);
143 pm = med3(pl, pm, pn, cmp);
146 pa = pb = (char *) a + es;
148 pc = pd = (char *) a + (n - 1) * es;
151 while (pb <= pc && (r = cmp(pb, a)) <= 0)
161 while (pb <= pc && (r = cmp(pc, a)) >= 0)
179 { /* Switch to insertion sort */
180 for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
181 for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
187 pn = (char *) a + n * es;
188 r = min(pa - (char *) a, pb - pa);
189 vecswap(a, pb - r, r);
190 r = min(pd - pc, pn - pd - es);
191 vecswap(pb, pn - r, r);
192 if ((r = pb - pa) > es)
193 qsort(a, r / es, es, cmp);
194 if ((r = pd - pc) > es)
196 /* Iterate rather than recurse to save stack space */
201 /* qsort(pn - r, r / es, es, cmp);*/