denyhosts/clamav/libclamav/qsort.c

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/*-
* 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 HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <stdlib.h>
#include "clamav.h"
#include "platform.h"
#include "others.h"
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// clang-format off
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static inline char *med3(char *, char *, char *, int (*)(const void *, const void *));
static inline char *med3_r(void *, char *, char *, char *, int (*)(const void *, const void *, const void *));
static inline void swapfunc(char *, char *, int, int);
/*
* Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
*/
#define swapcode(TYPE, parmi, parmj, n) \
{ \
long i = (n) / sizeof(TYPE); \
register TYPE *pi = (TYPE *)(parmi); \
register TYPE *pj = (TYPE *)(parmj); \
do { \
register 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 \
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: es == sizeof(long) ? 0 \
: 1;
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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)
#define CMP1(a, b) ((int)(*((uint32_t *)(a)) - *((uint32_t *)(b))))
#define CMP(a, b) (cmp ? (cmp(a, b)) : CMP1(a, b))
#define CMP_R(arg, a, b) (cmp ? (cmp(arg, a, b)) : CMP1(a, b))
#define MED3(a, b, c, d) (d ? (med3(a, b, c, d)) : (CMP1(a, b) < 0 ? (CMP1(b, c) < 0 ? (b) : (CMP1(a, c) < 0 ? (c) : (a))) : (CMP1(b, c) > 0 ? (b) : (CMP1(a, c) < 0 ? (a) : (c)))))
#define MED3_R(arg, a, b, c, d) (d ? (med3_r(arg, a, b, c, d)) : (CMP1(a, b) < 0 ? (CMP1(b, c) < 0 ? (b) : (CMP1(a, c) < 0 ? (c) : (a))) : (CMP1(b, c) > 0 ? (b) : (CMP1(a, c) < 0 ? (a) : (c)))))
static inline char *
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med3(a, b, c, cmp) char *a, *b, *c;
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int (*cmp)(const void *, const void *);
{
return CMP(a, b) < 0 ? (CMP(b, c) < 0 ? b : (CMP(a, c) < 0 ? c : a))
: (CMP(b, c) > 0 ? b : (CMP(a, c) < 0 ? a : c));
}
static inline char *
med3_r(arg, a, b, c, cmp) void *arg;
char *a, *b, *c;
int (*cmp)(const void *, const void *, const void *);
{
return CMP_R(arg, a, b) < 0 ? (CMP_R(arg, b, c) < 0 ? b : (CMP_R(arg, a, c) < 0 ? c : a))
: (CMP_R(arg, b, c) > 0 ? b : (CMP_R(arg, a, c) < 0 ? a : c));
}
void cli_qsort(void *a, size_t n, size_t es, int (*cmp)(const void *, const void *))
{
char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
int d, r, 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(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);
pm = MED3(pm - d, pm, pm + d, cmp);
pn = MED3(pn - 2 * d, pn - d, pn, cmp);
}
pm = MED3(pl, pm, pn, cmp);
}
swap(a, pm);
pa = pb = (char *)a + es;
pc = pd = (char *)a + (n - 1) * es;
for (;;) {
while (pb <= pc && (r = CMP(pb, a)) <= 0) {
if (r == 0) {
swap_cnt = 1;
swap(pa, pb);
pa += es;
}
pb += es;
}
while (pb <= pc && (r = CMP(pc, a)) >= 0) {
if (r == 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(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((size_t)(pd - pc), (size_t)(pn - pd - es));
vecswap(pb, pn - r, r);
if ((size_t)(r = pb - pa) > es)
cli_qsort(a, r / es, es, cmp);
if ((size_t)(r = pd - pc) > es) {
/* Iterate rather than recurse to save stack space */
a = pn - r;
n = r / es;
goto loop;
}
/* cli_qsort(pn - r, r / es, es, cmp);*/
}
void cli_qsort_r(void *a, size_t n, size_t es, int (*cmp)(const void *, const void *, const void *), void *arg)
{
char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
int d, r, 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_R(arg, 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_R(arg, pl, pl + d, pl + 2 * d, cmp);
pm = MED3_R(arg, pm - d, pm, pm + d, cmp);
pn = MED3_R(arg, pn - 2 * d, pn - d, pn, cmp);
}
pm = MED3_R(arg, pl, pm, pn, cmp);
}
swap(a, pm);
pa = pb = (char *)a + es;
pc = pd = (char *)a + (n - 1) * es;
for (;;) {
while (pb <= pc && (r = CMP_R(arg, pb, a)) <= 0) {
if (r == 0) {
swap_cnt = 1;
swap(pa, pb);
pa += es;
}
pb += es;
}
while (pb <= pc && (r = CMP_R(arg, pc, a)) >= 0) {
if (r == 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_R(arg, 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((size_t)(pd - pc), (size_t)(pn - pd - es));
vecswap(pb, pn - r, r);
if ((size_t)(r = pb - pa) > es)
cli_qsort_r(a, r / es, es, cmp, arg);
if ((size_t)(r = pd - pc) > es) {
/* Iterate rather than recurse to save stack space */
a = pn - r;
n = r / es;
goto loop;
}
/* cli_qsort_r(pn - r, r / es, es, cmp);*/
}
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// clang-format on