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authorUlrich Drepper <drepper@redhat.com>1996-12-20 01:39:50 +0000
committerUlrich Drepper <drepper@redhat.com>1996-12-20 01:39:50 +0000
commit6d52618b15cbe25ed4822ac51321db292f28ccda (patch)
treebafef072c0f5cb67c09d7c1789888d4310ac568f /stdlib/qsort.c
parent10dc2a90b7f86d9bc1be9d1b9305a781882f7ac5 (diff)
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Update from main archive 961219cvs/libc-961220
Thu Dec 19 23:28:33 1996 Ulrich Drepper <drepper@cygnus.com> * resolv/resolv.h: Update from BIND 4.9.5-P1. * resolv/res_comp.c: Likewise. * resolv/res_debug.c: Likewise. * resolv/Banner: Update version number. Thu Dec 19 20:58:53 1996 Ulrich Drepper <drepper@cygnus.com> * elf/dlfcn.h: Add extern "C" wrapper. * io/utime.h: Don't define NULL since this isn't allowed in POSIX. * io/sys/stat.h: Declare `lstat' only if __USE_BSD || __USE_XOPEN_EXTENDED. * locale/locale.h: Define NULL. * math/math.c: Don't include <errno.h> to define math errors. * stdlib/stdlib.h: Likewise. * posix/unistd.h: Don't declare environ. * posix/sys/utsname.h (struct utsname): Declare member domainname as __domainname is !__USE_GNU. * signal/signal.h: Declare size_t only if __USE_BSD || __USE_XOPEN_EXTENDED. * stdio/stdio.h: Don't declare cuserid when __USE_POSIX, but instead when __USE_XOPEN. * string/string.h: Define strndup only if __USE_GNU. * sysdeps/unix/sysv/linux/clock.c: New file. * sysdeps/unix/sysv/linux/timebits.h: Define CLOCKS_PER_SEC as 1000000 per X/Open standard. * features.h: Add code to recognize _POSIX_C_SOURCE value 199309. Define __USE_POSIX199309. * posix/unistd.h: Declare fdatasync only if __USE_POSIX199309. * time/time.c: Declare nanosleep only if __USE_POSIX199309. Patches by Rüdiger Helsch <rh@unifix.de>. * locale/locale.h: Add declaration of newlocale and freelocale. * new-malloc/Makefile (distibute): Add mtrace.awk. (dist-routines): Add mcheck and mtrace. (install-lib, non-lib.a): Define as libmcheck.a. * new-malloc/malloc.h: Add declaration of __malloc_initialized. * new-malloc/mcheck.c: New file. * new-malloc/mcheck.h: New file. * new-malloc/mtrace.c: New file. * new-malloc/mtrace.awk: New file. * posix/unistd.h: Correct prototype for usleep. * sysdeps/unix/bsd/usleep.c: De-ANSI-declfy. Correct return type. * sysdeps/unix/sysv/linux/usleep.c: Real implementation based on nanosleep. * signal/signal.h: Change protoype of __sigpause to take two arguments. Remove prototype for sigpause. Add two different macros named sigpause selected when __USE_BSD or __USE_XOPEN are defined. This is necessary since the old BSD definition of theis function collides with the X/Open definition. * sysdeps/posix/sigpause.c: Change function definition to also fit X/Open definition. * sysdeps/libm-i387/e_exp.S: Make sure stack is empty when the function is left. * sysdeps/libm-i387/e_expl.S: Likewise. Patch by HJ Lu. 1996-12-17 Paul Eggert <eggert@twinsun.com> * many, many files: Spelling corrections. * catgets/catgetsinfo.h (mmapped): Renamed from mmaped (in struct catalog_info.status). * mach/err_kern.sub (err_codes_unix), string/stratcliff.c (main): Fix spelling in message. * po/libc.pot: Fix spelling in message for `zic'; this anticipates a fix in the tzcode distribution. Wed Dec 18 15:48:02 1996 Ulrich Drepper <drepper@cygnus.com> * time/strftime.c: Implement ^ flag to cause output be converted to use upper case characters. * time/zic.c: Update from ADO tzcode1996n. Wed Dec 18 14:29:24 1996 Erik Naggum <erik@naggum.no> * time/strftime.c (add): Don't change global `i' until all is over. Define NULL is not already defined. Tue Dec 17 09:49:03 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * libio/iovsprintf.c (_IO_vsprintf): Change `&sf' to `&sf._sbf._f' to avoid the need for a cast. * libio/iovsscanf.c (_IO_vsscanf): Likewise. * sunrpc/rpc/xdr.h: Add prototype for xdr_free.
Diffstat (limited to 'stdlib/qsort.c')
-rw-r--r--stdlib/qsort.c83
1 files changed, 41 insertions, 42 deletions
diff --git a/stdlib/qsort.c b/stdlib/qsort.c
index bc8d171b79..0c83c48569 100644
--- a/stdlib/qsort.c
+++ b/stdlib/qsort.c
@@ -1,21 +1,21 @@
-/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
-Written by Douglas C. Schmidt (schmidt@ics.uci.edu).
+/* Copyright (C) 1991, 1992, 1996 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Written by Douglas C. Schmidt (schmidt@ics.uci.edu).
-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 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.
+ 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. */
+ 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., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
#include <ansidecl.h>
#include <stdlib.h>
@@ -40,7 +40,7 @@ Cambridge, MA 02139, USA. */
#define MAX_THRESH 4
/* Stack node declarations used to store unfulfilled partition obligations. */
-typedef struct
+typedef struct
{
char *lo;
char *hi;
@@ -50,26 +50,26 @@ typedef struct
#define STACK_SIZE (8 * sizeof(unsigned long int))
#define PUSH(low, high) ((void) ((top->lo = (low)), (top->hi = (high)), ++top))
#define POP(low, high) ((void) (--top, (low = top->lo), (high = top->hi)))
-#define STACK_NOT_EMPTY (stack < top)
+#define STACK_NOT_EMPTY (stack < top)
/* Order size using quicksort. This implementation incorporates
four optimizations discussed in Sedgewick:
- 1. Non-recursive, using an explicit stack of pointer that store the
- next array partition to sort. To save time, this maximum amount
- of space required to store an array of MAX_INT is allocated on the
- stack. Assuming a 32-bit integer, this needs only 32 *
+ 1. Non-recursive, using an explicit stack of pointer that store the
+ next array partition to sort. To save time, this maximum amount
+ of space required to store an array of MAX_INT is allocated on the
+ stack. Assuming a 32-bit integer, this needs only 32 *
sizeof(stack_node) == 136 bits. Pretty cheap, actually.
2. Chose the pivot element using a median-of-three decision tree.
- This reduces the probability of selecting a bad pivot value and
+ This reduces the probability of selecting a bad pivot value and
eliminates certain extraneous comparisons.
3. Only quicksorts TOTAL_ELEMS / MAX_THRESH partitions, leaving
- insertion sort to order the MAX_THRESH items within each partition.
+ insertion sort to order the MAX_THRESH items within each partition.
This is a big win, since insertion sort is faster for small, mostly
- sorted array segements.
+ sorted array segments.
4. The larger of the two sub-partitions is always pushed onto the
stack first, with the algorithm then concentrating on the
@@ -108,8 +108,8 @@ DEFUN(_quicksort, (pbase, total_elems, size, cmp),
char *pivot = pivot_buffer;
/* Select median value from among LO, MID, and HI. Rearrange
- LO and HI so the three values are sorted. This lowers the
- probability of picking a pathological pivot value and
+ LO and HI so the three values are sorted. This lowers the
+ probability of picking a pathological pivot value and
skips a comparison for both the LEFT_PTR and RIGHT_PTR. */
char *mid = lo + size * ((hi - lo) / size >> 1);
@@ -118,7 +118,7 @@ DEFUN(_quicksort, (pbase, total_elems, size, cmp),
SWAP(mid, lo, size);
if ((*cmp)((PTR) hi, (PTR) mid) < 0)
SWAP(mid, hi, size);
- else
+ else
goto jump_over;
if ((*cmp)((PTR) mid, (PTR) lo) < 0)
SWAP(mid, lo, size);
@@ -127,12 +127,12 @@ DEFUN(_quicksort, (pbase, total_elems, size, cmp),
pivot = pivot_buffer;
left_ptr = lo + size;
- right_ptr = hi - size;
+ right_ptr = hi - size;
- /* Here's the famous ``collapse the walls'' section of quicksort.
- Gotta like those tight inner loops! They are the main reason
+ /* Here's the famous ``collapse the walls'' section of quicksort.
+ Gotta like those tight inner loops! They are the main reason
that this algorithm runs much faster than others. */
- do
+ do
{
while ((*cmp)((PTR) left_ptr, (PTR) pivot) < 0)
left_ptr += size;
@@ -140,23 +140,23 @@ DEFUN(_quicksort, (pbase, total_elems, size, cmp),
while ((*cmp)((PTR) pivot, (PTR) right_ptr) < 0)
right_ptr -= size;
- if (left_ptr < right_ptr)
+ if (left_ptr < right_ptr)
{
SWAP(left_ptr, right_ptr, size);
left_ptr += size;
right_ptr -= size;
}
- else if (left_ptr == right_ptr)
+ else if (left_ptr == right_ptr)
{
left_ptr += size;
right_ptr -= size;
break;
}
- }
+ }
while (left_ptr <= right_ptr);
/* Set up pointers for next iteration. First determine whether
- left and right partitions are below the threshold size. If so,
+ left and right partitions are below the threshold size. If so,
ignore one or both. Otherwise, push the larger partition's
bounds on the stack and continue sorting the smaller one. */
@@ -164,22 +164,22 @@ DEFUN(_quicksort, (pbase, total_elems, size, cmp),
{
if ((size_t) (hi - left_ptr) <= max_thresh)
/* Ignore both small partitions. */
- POP(lo, hi);
+ POP(lo, hi);
else
- /* Ignore small left partition. */
+ /* Ignore small left partition. */
lo = left_ptr;
}
else if ((size_t) (hi - left_ptr) <= max_thresh)
/* Ignore small right partition. */
hi = right_ptr;
else if ((right_ptr - lo) > (hi - left_ptr))
- {
+ {
/* Push larger left partition indices. */
PUSH(lo, right_ptr);
lo = left_ptr;
}
else
- {
+ {
/* Push larger right partition indices. */
PUSH(left_ptr, hi);
hi = right_ptr;
@@ -188,8 +188,8 @@ DEFUN(_quicksort, (pbase, total_elems, size, cmp),
}
/* Once the BASE_PTR array is partially sorted by quicksort the rest
- is completely sorted using insertion sort, since this is efficient
- for partitions below MAX_THRESH size. BASE_PTR points to the beginning
+ is completely sorted using insertion sort, since this is efficient
+ for partitions below MAX_THRESH size. BASE_PTR points to the beginning
of the array to sort, and END_PTR points at the very last element in
the array (*not* one beyond it!). */
@@ -240,4 +240,3 @@ DEFUN(_quicksort, (pbase, total_elems, size, cmp),
}
}
}
-