mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
d861d2787b
OpenBSD's qsort() function is more secure than the ones used by FreeBSD, NetBSD and MacOS. The best part is it goes faster too! This change also imports the OpenBSD mergesort() and heapsort()
362 lines
11 KiB
C
362 lines
11 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
|
|
│vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi│
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright (c) 1991, 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. │
|
|
│ 3. 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. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/macros.internal.h"
|
|
#include "libc/mem/alg.h"
|
|
#include "libc/mem/mem.h"
|
|
#include "libc/str/str.h"
|
|
#include "libc/sysv/errfuns.h"
|
|
// clang-format off
|
|
|
|
asm(".ident\t\"\\n\\n\
|
|
OpenBSD Sorting (BSD-3)\\n\
|
|
Copyright 1993 The Regents of the University of California\"");
|
|
asm(".include \"libc/disclaimer.inc\"");
|
|
|
|
/*
|
|
* Hybrid exponential search/linear search merge sort with hybrid
|
|
* natural/pairwise first pass. Requires about .3% more comparisons
|
|
* for random data than LSMS with pairwise first pass alone.
|
|
* It works for objects as small as two bytes.
|
|
*/
|
|
|
|
#define NATURAL
|
|
#define THRESHOLD 16 /* Best choice for natural merge cut-off. */
|
|
|
|
/* #define NATURAL to get hybrid natural merge.
|
|
* (The default is pairwise merging.)
|
|
*/
|
|
|
|
static void setup(uint8_t *, uint8_t *, size_t, size_t, int (*)(), void *);
|
|
static void insertionsort(uint8_t *, size_t, size_t, int (*)(), void *);
|
|
|
|
#define ISIZE sizeof(int)
|
|
#define PSIZE sizeof(uint8_t *)
|
|
#define ICOPY_LIST(src, dst, last) \
|
|
do \
|
|
*(int*)dst = *(int*)src, src += ISIZE, dst += ISIZE; \
|
|
while(src < last)
|
|
#define ICOPY_ELT(src, dst, i) \
|
|
do \
|
|
*(int*) dst = *(int*) src, src += ISIZE, dst += ISIZE; \
|
|
while (i -= ISIZE)
|
|
|
|
#define CCOPY_LIST(src, dst, last) \
|
|
do \
|
|
*dst++ = *src++; \
|
|
while (src < last)
|
|
#define CCOPY_ELT(src, dst, i) \
|
|
do \
|
|
*dst++ = *src++; \
|
|
while (i -= 1)
|
|
|
|
/*
|
|
* Find the next possible pointer head. (Trickery for forcing an array
|
|
* to do double duty as a linked list when objects do not align with word
|
|
* boundaries.
|
|
*/
|
|
/* Assumption: PSIZE is a power of 2. */
|
|
#define EVAL(p) (uint8_t **) \
|
|
((uint8_t *)0 + \
|
|
(((uint8_t *)p + PSIZE - 1 - (uint8_t *) 0) & ~(PSIZE - 1)))
|
|
|
|
/**
|
|
* Sorts array.
|
|
*
|
|
* @param vbase is base of array
|
|
* @param nmemb is item count
|
|
* @param size is item width
|
|
* @param cmp is a callback returning <0, 0, or >0
|
|
* @see mergesort_r()
|
|
* @see heapsort()
|
|
* @see qsort()
|
|
*/
|
|
int
|
|
mergesort(void *base, size_t nmemb, size_t size,
|
|
int (*cmp)(const void *, const void *))
|
|
{
|
|
return mergesort_r(base, nmemb, size, (void *)cmp, 0);
|
|
}
|
|
|
|
/**
|
|
* Sorts array w/ optional callback argument.
|
|
*
|
|
* @param base is base of array
|
|
* @param nmemb is item count
|
|
* @param size is item width
|
|
* @param cmp is a callback returning <0, 0, or >0
|
|
* @param z will optionally be passed as the third argument to cmp
|
|
* @see mergesort()
|
|
*/
|
|
int
|
|
mergesort_r(void *base, size_t nmemb, size_t size,
|
|
int (*cmp)(const void *, const void *, void *), void *z)
|
|
{
|
|
int i, sense;
|
|
int big, iflag;
|
|
uint8_t *f1, *f2, *t, *b, *tp2, *q, *l1, *l2;
|
|
uint8_t *list2, *list1, *p2, *p, *last, **p1;
|
|
|
|
if (size < PSIZE / 2) /* Pointers must fit into 2 * size. */
|
|
return (einval());
|
|
|
|
if (nmemb == 0)
|
|
return (0);
|
|
|
|
/*
|
|
* XXX
|
|
* Stupid subtraction for the Cray.
|
|
*/
|
|
iflag = 0;
|
|
if (!(size % ISIZE) && !(((char *)base - (char *)0) % ISIZE))
|
|
iflag = 1;
|
|
|
|
if ((list2 = malloc(nmemb * size + PSIZE)) == NULL)
|
|
return (-1);
|
|
|
|
list1 = base;
|
|
setup(list1, list2, nmemb, size, cmp, z);
|
|
last = list2 + nmemb * size;
|
|
i = big = 0;
|
|
while (*EVAL(list2) != last) {
|
|
l2 = list1;
|
|
p1 = EVAL(list1);
|
|
for (tp2 = p2 = list2; p2 != last; p1 = EVAL(l2)) {
|
|
p2 = *EVAL(p2);
|
|
f1 = l2;
|
|
f2 = l1 = list1 + (p2 - list2);
|
|
if (p2 != last)
|
|
p2 = *EVAL(p2);
|
|
l2 = list1 + (p2 - list2);
|
|
while (f1 < l1 && f2 < l2) {
|
|
if ((*cmp)(f1, f2, z) <= 0) {
|
|
q = f2;
|
|
b = f1, t = l1;
|
|
sense = -1;
|
|
} else {
|
|
q = f1;
|
|
b = f2, t = l2;
|
|
sense = 0;
|
|
}
|
|
if (!big) { /* here i = 0 */
|
|
while ((b += size) < t && cmp(q, b, z) >sense)
|
|
if (++i == 6) {
|
|
big = 1;
|
|
goto EXPONENTIAL;
|
|
}
|
|
} else {
|
|
EXPONENTIAL: for (i = size; ; i <<= 1)
|
|
if ((p = (b + i)) >= t) {
|
|
if ((p = t - size) > b &&
|
|
(*cmp)(q, p, z) <= sense)
|
|
t = p;
|
|
else
|
|
b = p;
|
|
break;
|
|
} else if ((*cmp)(q, p, z) <= sense) {
|
|
t = p;
|
|
if (i == size)
|
|
big = 0;
|
|
goto FASTCASE;
|
|
} else
|
|
b = p;
|
|
while (t > b+size) {
|
|
i = (((t - b) / size) >> 1) * size;
|
|
if ((*cmp)(q, p = b + i, z) <= sense)
|
|
t = p;
|
|
else
|
|
b = p;
|
|
}
|
|
goto COPY;
|
|
FASTCASE: while (i > size)
|
|
if ((*cmp)(q, p = b + (i >>= 1), z)
|
|
<= sense)
|
|
t = p;
|
|
else
|
|
b = p;
|
|
COPY: b = t;
|
|
}
|
|
i = size;
|
|
if (q == f1) {
|
|
if (iflag) {
|
|
ICOPY_LIST(f2, tp2, b);
|
|
ICOPY_ELT(f1, tp2, i);
|
|
} else {
|
|
CCOPY_LIST(f2, tp2, b);
|
|
CCOPY_ELT(f1, tp2, i);
|
|
}
|
|
} else {
|
|
if (iflag) {
|
|
ICOPY_LIST(f1, tp2, b);
|
|
ICOPY_ELT(f2, tp2, i);
|
|
} else {
|
|
CCOPY_LIST(f1, tp2, b);
|
|
CCOPY_ELT(f2, tp2, i);
|
|
}
|
|
}
|
|
}
|
|
if (f2 < l2) {
|
|
if (iflag)
|
|
ICOPY_LIST(f2, tp2, l2);
|
|
else
|
|
CCOPY_LIST(f2, tp2, l2);
|
|
} else if (f1 < l1) {
|
|
if (iflag)
|
|
ICOPY_LIST(f1, tp2, l1);
|
|
else
|
|
CCOPY_LIST(f1, tp2, l1);
|
|
}
|
|
*p1 = l2;
|
|
}
|
|
tp2 = list1; /* swap list1, list2 */
|
|
list1 = list2;
|
|
list2 = tp2;
|
|
last = list2 + nmemb*size;
|
|
}
|
|
if (base == list2) {
|
|
memmove(list2, list1, nmemb*size);
|
|
list2 = list1;
|
|
}
|
|
free(list2);
|
|
return (0);
|
|
}
|
|
|
|
#define swap(a, b) { \
|
|
s = b; \
|
|
i = size; \
|
|
do { \
|
|
tmp = *a; *a++ = *s; *s++ = tmp; \
|
|
} while (--i); \
|
|
a -= size; \
|
|
}
|
|
#define reverse(bot, top) { \
|
|
s = top; \
|
|
do { \
|
|
i = size; \
|
|
do { \
|
|
tmp = *bot; *bot++ = *s; *s++ = tmp; \
|
|
} while (--i); \
|
|
s -= size2; \
|
|
} while(bot < s); \
|
|
}
|
|
|
|
/*
|
|
* Optional hybrid natural/pairwise first pass. Eats up list1 in runs of
|
|
* increasing order, list2 in a corresponding linked list. Checks for runs
|
|
* when THRESHOLD/2 pairs compare with same sense. (Only used when NATURAL
|
|
* is defined. Otherwise simple pairwise merging is used.)
|
|
*/
|
|
void
|
|
setup(uint8_t *list1, uint8_t *list2, size_t n, size_t size,
|
|
int (*cmp)(const void *, const void *, void *), void *z)
|
|
{
|
|
int i, length, size2, sense;
|
|
uint8_t tmp, *f1, *f2, *s, *l2, *last, *p2;
|
|
|
|
size2 = size*2;
|
|
if (n <= 5) {
|
|
insertionsort(list1, n, size, cmp, z);
|
|
*EVAL(list2) = (uint8_t*) list2 + n*size;
|
|
return;
|
|
}
|
|
/*
|
|
* Avoid running pointers out of bounds; limit n to evens
|
|
* for simplicity.
|
|
*/
|
|
i = 4 + (n & 1);
|
|
insertionsort(list1 + (n - i) * size, i, size, cmp, z);
|
|
last = list1 + size * (n - i);
|
|
*EVAL(list2 + (last - list1)) = list2 + n * size;
|
|
|
|
#ifdef NATURAL
|
|
p2 = list2;
|
|
f1 = list1;
|
|
sense = (cmp(f1, f1 + size, z) > 0);
|
|
for (; f1 < last; sense = !sense) {
|
|
length = 2;
|
|
/* Find pairs with same sense. */
|
|
for (f2 = f1 + size2; f2 < last; f2 += size2) {
|
|
if ((cmp(f2, f2+ size, z) > 0) != sense)
|
|
break;
|
|
length += 2;
|
|
}
|
|
if (length < THRESHOLD) { /* Pairwise merge */
|
|
do {
|
|
p2 = *EVAL(p2) = f1 + size2 - list1 + list2;
|
|
if (sense > 0)
|
|
swap (f1, f1 + size);
|
|
} while ((f1 += size2) < f2);
|
|
} else { /* Natural merge */
|
|
l2 = f2;
|
|
for (f2 = f1 + size2; f2 < l2; f2 += size2) {
|
|
if ((cmp(f2-size, f2, z) > 0) != sense) {
|
|
p2 = *EVAL(p2) = f2 - list1 + list2;
|
|
if (sense > 0)
|
|
reverse(f1, f2-size);
|
|
f1 = f2;
|
|
}
|
|
}
|
|
if (sense > 0)
|
|
reverse (f1, f2-size);
|
|
f1 = f2;
|
|
if (f2 < last || cmp(f2 - size, f2, z) > 0)
|
|
p2 = *EVAL(p2) = f2 - list1 + list2;
|
|
else
|
|
p2 = *EVAL(p2) = list2 + n*size;
|
|
}
|
|
}
|
|
#else /* pairwise merge only. */
|
|
for (f1 = list1, p2 = list2; f1 < last; f1 += size2) {
|
|
p2 = *EVAL(p2) = p2 + size2;
|
|
if (cmp (f1, f1 + size, z) > 0)
|
|
swap(f1, f1 + size);
|
|
}
|
|
#endif /* NATURAL */
|
|
}
|
|
|
|
/*
|
|
* This is to avoid out-of-bounds addresses in sorting the
|
|
* last 4 elements.
|
|
*/
|
|
static void
|
|
insertionsort(uint8_t *a, size_t n, size_t size,
|
|
int (*cmp)(const void *, const void *, void *), void *z)
|
|
{
|
|
uint8_t *ai, *s, *t, *u, tmp;
|
|
int i;
|
|
|
|
for (ai = a+size; --n >= 1; ai += size)
|
|
for (t = ai; t > a; t -= size) {
|
|
u = t - size;
|
|
if (cmp(u, t, z) <= 0)
|
|
break;
|
|
swap(u, t);
|
|
}
|
|
}
|