glibc/stdlib/msort.c
Roland McGrath 600927014b Wed Sep 20 18:02:03 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu>
* locale/locale.c: Include errno.h.
	* locale/localedef.c: Likewise.

Tue Sep 19 00:02:06 1995  Roland McGrath  <roland@churchy.gnu.ai.mit.edu>

	* Makefile (distclean-1): Remove config.cache, config.log, config.h.
	(parent-mostlyclean): Remove all flavors of the parent library.

	* misc/mntent.c (getmntent): Skip multiple whitespace chars
	between fields.

	* hurd/hurdstartup.c (_hurd_startup): If RPC returns
	EXEC_STACK_ARGS flag, get args from stack.
	If args on stack but have info from RPC, relocate args on stack to make
	space for struct hurd_startup_data.

	* elf/dl-object.c: Include errno.h.
	* posix/execvp.c: Likewise.
	* dirent/scandir.c: Likewise.
	* sysdeps/posix/system.c: Likewise.
	* sysdeps/generic/setenv.c: Likewise.
	* stdlib/msort.c: Likewise.
	* stdio/memstream.c: Likewise.
	* stdio/fclose.c: Likewise.
	* stdio/getdelim.c: Likewise.
	* stdio/setvbuf.c: Likewise.
	* sysdeps/ieee754/ldexp.c: Likewise.
	* locale/locfile-parse.c: Likewise.

	* stdlib/lcong48_r.c: Don't check for null argument; let it fault.
	* stdlib/seed48_r.c: Likewise.
	* stdlib/srand48_r.c: Likewise.
	* stdlib/jrand48_r.c: Likewise.
	* stdlib/nrand48_r.c: Likewise.

	* misc/search.h: Many decls for hsearch functions.
1995-09-21 04:01:40 +00:00

117 lines
2.7 KiB
C

/* msort -- an alternative to qsort, with an identical interface.
Copyright (C) 1992, 1995 Free Software Foundation, Inc.
Written by Mike Haertel, September 1988.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <stdlib.h>
#include <string.h>
#include <memcopy.h>
#include <errno.h>
static void
DEFUN(msort_with_tmp, (b, n, s, cmp, t),
PTR b AND size_t n AND size_t s AND __compar_fn_t cmp AND char *t)
{
char *tmp;
char *b1, *b2;
size_t n1, n2;
if (n <= 1)
return;
n1 = n / 2;
n2 = n - n1;
b1 = b;
b2 = (char *) b + (n1 * s);
msort_with_tmp (b1, n1, s, cmp, t);
msort_with_tmp (b2, n2, s, cmp, t);
tmp = t;
if (s == OPSIZ && (b1 - (char *) 0) % OPSIZ == 0)
/* We are operating on aligned words. Use direct word stores. */
while (n1 > 0 && n2 > 0)
{
if ((*cmp) (b1, b2) <= 0)
{
--n1;
*((op_t *) tmp)++ = *((op_t *) b1)++;
}
else
{
--n2;
*((op_t *) tmp)++ = *((op_t *) b2)++;
}
}
else
while (n1 > 0 && n2 > 0)
{
if ((*cmp) (b1, b2) <= 0)
{
memcpy (tmp, b1, s);
b1 += s;
--n1;
}
else
{
memcpy (tmp, b2, s);
b2 += s;
--n2;
}
tmp += s;
}
if (n1 > 0)
memcpy (tmp, b1, n1 * s);
memcpy (b, t, (n - n2) * s);
}
void
DEFUN(qsort, (b, n, s, cmp),
PTR b AND size_t n AND size_t s AND __compar_fn_t cmp)
{
CONST size_t size = n * s;
if (size < 1024)
/* The temporary array is small, so put it on the stack. */
msort_with_tmp (b, n, s, cmp, __alloca (size));
else
{
/* It's somewhat large, so malloc it. */
int save = errno;
char *tmp = malloc (size);
if (tmp == NULL)
{
/* Couldn't get space, so use the slower algorithm
that doesn't need a temporary array. */
extern void EXFUN(_quicksort, (PTR __base,
size_t __nmemb, size_t __size,
__compar_fn_t __compar));
_quicksort (b, n, s, cmp);
}
else
{
msort_with_tmp (b, n, s, cmp, tmp);
free (tmp);
}
errno = save;
}
}