libc: import qsort from freebsd

libc/build.mak

@@ -11,3 +11,4 @@ libc += time.o
 libc += ctype.o
 libc += signal.o
 libc += mman.o
+libc += qsort.o

libc/qsort.c

+/*-
+ * Copyright (c) 1992, 1993
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)qsort.c     8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/cdefs.h>
+//__FBSDID("$FreeBSD$");
+
+#define __unused __attribute__((unused))
+
+#include <stdlib.h>
+
+#ifdef I_AM_QSORT_R
+typedef int              cmp_t(void *, const void *, const void *);
+#else
+typedef int              cmp_t(const void *, const void *);
+#endif
+static inline char      *med3(char *, char *, char *, cmp_t *, void *);
+static inline void       swapfunc(char *, char *, int, int);
+
+#define min(a, b)       (a) < (b) ? a : b
+
+/*
+ * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
+ */
+#define swapcode(TYPE, parmi, parmj, n) {               \
+        long i = (n) / sizeof (TYPE);                   \
+        TYPE *pi = (TYPE *) (parmi);            \
+        TYPE *pj = (TYPE *) (parmj);            \
+        do {                                            \
+                TYPE    t = *pi;                \
+                *pi++ = *pj;                            \
+                *pj++ = t;                              \
+        } while (--i > 0);                              \
+}
+
+#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
+        es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
+
+static inline void
+swapfunc(a, b, n, swaptype)
+        char *a, *b;
+        int n, swaptype;
+{
+        if(swaptype <= 1)
+                swapcode(long, a, b, n)
+        else
+                swapcode(char, a, b, n)
+}
+
+#define swap(a, b)                                      \
+        if (swaptype == 0) {                            \
+                long t = *(long *)(a);                  \
+                *(long *)(a) = *(long *)(b);            \
+                *(long *)(b) = t;                       \
+        } else                                          \
+                swapfunc(a, b, es, swaptype)
+
+#define vecswap(a, b, n)        if ((n) > 0) swapfunc(a, b, n, swaptype)
+
+#ifdef I_AM_QSORT_R
+#define CMP(t, x, y) (cmp((t), (x), (y)))
+#else
+#define CMP(t, x, y) (cmp((x), (y)))
+#endif
+
+static inline char *
+med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk
+#ifndef I_AM_QSORT_R
+__unused
+#endif
+)
+{
+        return CMP(thunk, a, b) < 0 ?
+               (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a ))
+              :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));
+}
+
+#ifdef I_AM_QSORT_R
+void
+qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
+#else
+#define thunk NULL
+void
+qsort(void *a, size_t n, size_t es, cmp_t *cmp)
+#endif
+{
+        char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
+        size_t d, r;
+        int cmp_result;
+        int swaptype, swap_cnt;
+
+loop:   SWAPINIT(a, es);
+        swap_cnt = 0;
+        if (n < 7) {
+                for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
+                        for (pl = pm;
+                             pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
+                             pl -= es)
+                                swap(pl, pl - es);
+                return;
+        }
+        pm = (char *)a + (n / 2) * es;
+        if (n > 7) {
+                pl = a;
+                pn = (char *)a + (n - 1) * es;
+                if (n > 40) {
+                        d = (n / 8) * es;
+                        pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);
+                        pm = med3(pm - d, pm, pm + d, cmp, thunk);
+                        pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk);
+                }
+                pm = med3(pl, pm, pn, cmp, thunk);
+        }
+        swap(a, pm);
+        pa = pb = (char *)a + es;
+
+        pc = pd = (char *)a + (n - 1) * es;
+        for (;;) {
+                while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) {
+                        if (cmp_result == 0) {
+                                swap_cnt = 1;
+                                swap(pa, pb);
+                                pa += es;
+                        }
+                        pb += es;
+                }
+                while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) {
+                        if (cmp_result == 0) {
+                                swap_cnt = 1;
+                                swap(pc, pd);
+                                pd -= es;
+                        }
+                        pc -= es;
+                }
+                if (pb > pc)
+                        break;
+                swap(pb, pc);
+                swap_cnt = 1;
+                pb += es;
+                pc -= es;
+        }
+        if (swap_cnt == 0) {  /* Switch to insertion sort */
+                for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
+                        for (pl = pm;
+                             pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
+                             pl -= es)
+                                swap(pl, pl - es);
+                return;
+        }
+
+        pn = (char *)a + n * es;
+        r = min(pa - (char *)a, pb - pa);
+        vecswap(a, pb - r, r);
+        r = min(pd - pc, pn - pd - es);
+        vecswap(pb, pn - r, r);
+        if ((r = pb - pa) > es)
+#ifdef I_AM_QSORT_R
+                qsort_r(a, r / es, es, thunk, cmp);
+#else
+                qsort(a, r / es, es, cmp);
+#endif
+        if ((r = pd - pc) > es) {
+                /* Iterate rather than recurse to save stack space */
+                a = pn - r;
+                n = r / es;
+                goto loop;
+        }
+/*              qsort(pn - r, r / es, es, cmp);*/
+}