annotate src/stdlib/SDL_qsort.c @ 3230:816a7a65a59a

Fixed compiling SDL_fsaudio.c against fusionsound 1.0.0
author Couriersud <couriersud@arcor.de>
date Mon, 03 Aug 2009 18:07:31 +0000
parents dc1eb82ffdaa
children 0aaa7f52d1c6
rev   line source
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
1 /* qsort.c
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
2 * (c) 1998 Gareth McCaughan
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
3 *
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
4 * This is a drop-in replacement for the C library's |qsort()| routine.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
5 *
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
6 * Features:
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
7 * - Median-of-three pivoting (and more)
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
8 * - Truncation and final polishing by a single insertion sort
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
9 * - Early truncation when no swaps needed in pivoting step
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
10 * - Explicit recursion, guaranteed not to overflow
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
11 * - A few little wrinkles stolen from the GNU |qsort()|.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
12 * - separate code for non-aligned / aligned / word-size objects
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
13 *
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
14 * This code may be reproduced freely provided
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
15 * - this file is retained unaltered apart from minor
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
16 * changes for portability and efficiency
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
17 * - no changes are made to this comment
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
18 * - any changes that *are* made are clearly flagged
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
19 * - the _ID string below is altered by inserting, after
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
20 * the date, the string " altered" followed at your option
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
21 * by other material. (Exceptions: you may change the name
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
22 * of the exported routine without changing the ID string.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
23 * You may change the values of the macros TRUNC_* and
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
24 * PIVOT_THRESHOLD without changing the ID string, provided
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
25 * they remain constants with TRUNC_nonaligned, TRUNC_aligned
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
26 * and TRUNC_words/WORD_BYTES between 8 and 24, and
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
27 * PIVOT_THRESHOLD between 32 and 200.)
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
28 *
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
29 * You may use it in anything you like; you may make money
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
30 * out of it; you may distribute it in object form or as
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
31 * part of an executable without including source code;
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
32 * you don't have to credit me. (But it would be nice if
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
33 * you did.)
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
34 *
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
35 * If you find problems with this code, or find ways of
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
36 * making it significantly faster, please let me know!
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
37 * My e-mail address, valid as of early 1998 and certainly
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
38 * OK for at least the next 18 months, is
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
39 * gjm11@dpmms.cam.ac.uk
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
40 * Thanks!
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
41 *
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
42 * Gareth McCaughan Peterhouse Cambridge 1998
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
43 */
1402
d910939febfa Use consistent identifiers for the various platforms we support.
Sam Lantinga <slouken@libsdl.org>
parents: 1354
diff changeset
44 #include "SDL_config.h"
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
45
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
46 /*
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
47 #include <assert.h>
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
48 #include <stdlib.h>
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
49 #include <string.h>
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
50 */
1354
22f39393668a Fixed build problem with SDL_string.c
Sam Lantinga <slouken@libsdl.org>
parents: 1337
diff changeset
51 #include "SDL_stdinc.h"
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
52
1337
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
53 #define assert(X)
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
54 #define malloc SDL_malloc
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
55 #define free SDL_free
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
56 #define memcpy SDL_memcpy
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
57 #define memmove SDL_memmove
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
58 #define qsort SDL_qsort
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
59
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
60
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
61 #ifndef HAVE_QSORT
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
62
3162
dc1eb82ffdaa Von: Thomas Zimmermann
Sam Lantinga <slouken@libsdl.org>
parents: 1895
diff changeset
63 static const char _ID[] = "<qsort.c gjm 1.12 1998-03-19>";
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
64
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
65 /* How many bytes are there per word? (Must be a power of 2,
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
66 * and must in fact equal sizeof(int).)
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
67 */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
68 #define WORD_BYTES sizeof(int)
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
69
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
70 /* How big does our stack need to be? Answer: one entry per
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
71 * bit in a |size_t|.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
72 */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
73 #define STACK_SIZE (8*sizeof(size_t))
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
74
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
75 /* Different situations have slightly different requirements,
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
76 * and we make life epsilon easier by using different truncation
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
77 * points for the three different cases.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
78 * So far, I have tuned TRUNC_words and guessed that the same
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
79 * value might work well for the other two cases. Of course
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
80 * what works well on my machine might work badly on yours.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
81 */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
82 #define TRUNC_nonaligned 12
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
83 #define TRUNC_aligned 12
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
84 #define TRUNC_words 12*WORD_BYTES /* nb different meaning */
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
85
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
86 /* We use a simple pivoting algorithm for shortish sub-arrays
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
87 * and a more complicated one for larger ones. The threshold
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
88 * is PIVOT_THRESHOLD.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
89 */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
90 #define PIVOT_THRESHOLD 40
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
91
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
92 typedef struct
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
93 {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
94 char *first;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
95 char *last;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
96 } stack_entry;
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
97 #define pushLeft {stack[stacktop].first=ffirst;stack[stacktop++].last=last;}
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
98 #define pushRight {stack[stacktop].first=first;stack[stacktop++].last=llast;}
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
99 #define doLeft {first=ffirst;llast=last;continue;}
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
100 #define doRight {ffirst=first;last=llast;continue;}
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
101 #define pop {if (--stacktop<0) break;\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
102 first=ffirst=stack[stacktop].first;\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
103 last=llast=stack[stacktop].last;\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
104 continue;}
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
105
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
106 /* Some comments on the implementation.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
107 * 1. When we finish partitioning the array into "low"
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
108 * and "high", we forget entirely about short subarrays,
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
109 * because they'll be done later by insertion sort.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
110 * Doing lots of little insertion sorts might be a win
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
111 * on large datasets for locality-of-reference reasons,
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
112 * but it makes the code much nastier and increases
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
113 * bookkeeping overhead.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
114 * 2. We always save the shorter and get to work on the
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
115 * longer. This guarantees that every time we push
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
116 * an item onto the stack its size is <= 1/2 of that
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
117 * of its parent; so the stack can't need more than
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
118 * log_2(max-array-size) entries.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
119 * 3. We choose a pivot by looking at the first, last
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
120 * and middle elements. We arrange them into order
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
121 * because it's easy to do that in conjunction with
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
122 * choosing the pivot, and it makes things a little
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
123 * easier in the partitioning step. Anyway, the pivot
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
124 * is the middle of these three. It's still possible
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
125 * to construct datasets where the algorithm takes
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
126 * time of order n^2, but it simply never happens in
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
127 * practice.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
128 * 3' Newsflash: On further investigation I find that
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
129 * it's easy to construct datasets where median-of-3
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
130 * simply isn't good enough. So on large-ish subarrays
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
131 * we do a more sophisticated pivoting: we take three
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
132 * sets of 3 elements, find their medians, and then
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
133 * take the median of those.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
134 * 4. We copy the pivot element to a separate place
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
135 * because that way we can always do our comparisons
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
136 * directly against a pointer to that separate place,
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
137 * and don't have to wonder "did we move the pivot
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
138 * element?". This makes the inner loop better.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
139 * 5. It's possible to make the pivoting even more
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
140 * reliable by looking at more candidates when n
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
141 * is larger. (Taking this to its logical conclusion
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
142 * results in a variant of quicksort that doesn't
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
143 * have that n^2 worst case.) However, the overhead
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
144 * from the extra bookkeeping means that it's just
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
145 * not worth while.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
146 * 6. This is pretty clean and portable code. Here are
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
147 * all the potential portability pitfalls and problems
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
148 * I know of:
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
149 * - In one place (the insertion sort) I construct
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
150 * a pointer that points just past the end of the
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
151 * supplied array, and assume that (a) it won't
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
152 * compare equal to any pointer within the array,
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
153 * and (b) it will compare equal to a pointer
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
154 * obtained by stepping off the end of the array.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
155 * These might fail on some segmented architectures.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
156 * - I assume that there are 8 bits in a |char| when
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
157 * computing the size of stack needed. This would
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
158 * fail on machines with 9-bit or 16-bit bytes.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
159 * - I assume that if |((int)base&(sizeof(int)-1))==0|
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
160 * and |(size&(sizeof(int)-1))==0| then it's safe to
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
161 * get at array elements via |int*|s, and that if
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
162 * actually |size==sizeof(int)| as well then it's
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
163 * safe to treat the elements as |int|s. This might
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
164 * fail on systems that convert pointers to integers
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
165 * in non-standard ways.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
166 * - I assume that |8*sizeof(size_t)<=INT_MAX|. This
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
167 * would be false on a machine with 8-bit |char|s,
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
168 * 16-bit |int|s and 4096-bit |size_t|s. :-)
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
169 */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
170
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
171 /* The recursion logic is the same in each case: */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
172 #define Recurse(Trunc) \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
173 { size_t l=last-ffirst,r=llast-first; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
174 if (l<Trunc) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
175 if (r>=Trunc) doRight \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
176 else pop \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
177 } \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
178 else if (l<=r) { pushLeft; doRight } \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
179 else if (r>=Trunc) { pushRight; doLeft }\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
180 else doLeft \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
181 }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
182
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
183 /* and so is the pivoting logic: */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
184 #define Pivot(swapper,sz) \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
185 if ((size_t)(last-first)>PIVOT_THRESHOLD*sz) mid=pivot_big(first,mid,last,sz,compare);\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
186 else { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
187 if (compare(first,mid)<0) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
188 if (compare(mid,last)>0) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
189 swapper(mid,last); \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
190 if (compare(first,mid)>0) swapper(first,mid);\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
191 } \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
192 } \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
193 else { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
194 if (compare(mid,last)>0) swapper(first,last)\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
195 else { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
196 swapper(first,mid); \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
197 if (compare(mid,last)>0) swapper(mid,last);\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
198 } \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
199 } \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
200 first+=sz; last-=sz; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
201 }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
202
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
203 #ifdef DEBUG_QSORT
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
204 #include <stdio.h>
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
205 #endif
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
206
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
207 /* and so is the partitioning logic: */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
208 #define Partition(swapper,sz) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
209 int swapped=0; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
210 do { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
211 while (compare(first,pivot)<0) first+=sz; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
212 while (compare(pivot,last)<0) last-=sz; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
213 if (first<last) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
214 swapper(first,last); swapped=1; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
215 first+=sz; last-=sz; } \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
216 else if (first==last) { first+=sz; last-=sz; break; }\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
217 } while (first<=last); \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
218 if (!swapped) pop \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
219 }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
220
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
221 /* and so is the pre-insertion-sort operation of putting
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
222 * the smallest element into place as a sentinel.
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
223 * Doing this makes the inner loop nicer. I got this
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
224 * idea from the GNU implementation of qsort().
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
225 */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
226 #define PreInsertion(swapper,limit,sz) \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
227 first=base; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
228 last=first + (nmemb>limit ? limit : nmemb-1)*sz;\
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
229 while (last!=base) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
230 if (compare(first,last)>0) first=last; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
231 last-=sz; } \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
232 if (first!=base) swapper(first,(char*)base);
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
233
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
234 /* and so is the insertion sort, in the first two cases: */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
235 #define Insertion(swapper) \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
236 last=((char*)base)+nmemb*size; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
237 for (first=((char*)base)+size;first!=last;first+=size) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
238 char *test; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
239 /* Find the right place for |first|. \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
240 * My apologies for var reuse. */ \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
241 for (test=first-size;compare(test,first)>0;test-=size) ; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
242 test+=size; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
243 if (test!=first) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
244 /* Shift everything in [test,first) \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
245 * up by one, and place |first| \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
246 * where |test| is. */ \
1337
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
247 memcpy(pivot,first,size); \
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
248 memmove(test+size,test,first-test); \
c687f06c7473 Don't touch code that we brought in from other sources
Sam Lantinga <slouken@libsdl.org>
parents: 1336
diff changeset
249 memcpy(test,pivot,size); \
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
250 } \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
251 }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
252
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
253 #define SWAP_nonaligned(a,b) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
254 register char *aa=(a),*bb=(b); \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
255 register size_t sz=size; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
256 do { register char t=*aa; *aa++=*bb; *bb++=t; } while (--sz); }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
257
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
258 #define SWAP_aligned(a,b) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
259 register int *aa=(int*)(a),*bb=(int*)(b); \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
260 register size_t sz=size; \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
261 do { register int t=*aa;*aa++=*bb; *bb++=t; } while (sz-=WORD_BYTES); }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
262
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
263 #define SWAP_words(a,b) { \
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
264 register int t=*((int*)a); *((int*)a)=*((int*)b); *((int*)b)=t; }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
265
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
266 /* ---------------------------------------------------------------------- */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
267
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
268 static char *
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
269 pivot_big(char *first, char *mid, char *last, size_t size,
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
270 int compare(const void *, const void *))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
271 {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
272 size_t d = (((last - first) / size) >> 3) * size;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
273 char *m1, *m2, *m3;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
274 {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
275 char *a = first, *b = first + d, *c = first + 2 * d;
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
276 #ifdef DEBUG_QSORT
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
277 fprintf(stderr, "< %d %d %d\n", *(int *) a, *(int *) b, *(int *) c);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
278 #endif
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
279 m1 = compare(a, b) < 0 ?
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
280 (compare(b, c) < 0 ? b : (compare(a, c) < 0 ? c : a))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
281 : (compare(a, c) < 0 ? a : (compare(b, c) < 0 ? c : b));
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
282 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
283 {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
284 char *a = mid - d, *b = mid, *c = mid + d;
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
285 #ifdef DEBUG_QSORT
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
286 fprintf(stderr, ". %d %d %d\n", *(int *) a, *(int *) b, *(int *) c);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
287 #endif
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
288 m2 = compare(a, b) < 0 ?
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
289 (compare(b, c) < 0 ? b : (compare(a, c) < 0 ? c : a))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
290 : (compare(a, c) < 0 ? a : (compare(b, c) < 0 ? c : b));
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
291 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
292 {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
293 char *a = last - 2 * d, *b = last - d, *c = last;
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
294 #ifdef DEBUG_QSORT
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
295 fprintf(stderr, "> %d %d %d\n", *(int *) a, *(int *) b, *(int *) c);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
296 #endif
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
297 m3 = compare(a, b) < 0 ?
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
298 (compare(b, c) < 0 ? b : (compare(a, c) < 0 ? c : a))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
299 : (compare(a, c) < 0 ? a : (compare(b, c) < 0 ? c : b));
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
300 }
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
301 #ifdef DEBUG_QSORT
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
302 fprintf(stderr, "-> %d %d %d\n", *(int *) m1, *(int *) m2, *(int *) m3);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
303 #endif
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
304 return compare(m1, m2) < 0 ?
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
305 (compare(m2, m3) < 0 ? m2 : (compare(m1, m3) < 0 ? m3 : m1))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
306 : (compare(m1, m3) < 0 ? m1 : (compare(m2, m3) < 0 ? m3 : m2));
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
307 }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
308
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
309 /* ---------------------------------------------------------------------- */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
310
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
311 static void
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
312 qsort_nonaligned(void *base, size_t nmemb, size_t size,
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
313 int (*compare) (const void *, const void *))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
314 {
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
315
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
316 stack_entry stack[STACK_SIZE];
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
317 int stacktop = 0;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
318 char *first, *last;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
319 char *pivot = malloc(size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
320 size_t trunc = TRUNC_nonaligned * size;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
321 assert(pivot != 0);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
322
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
323 first = (char *) base;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
324 last = first + (nmemb - 1) * size;
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
325
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
326 if ((size_t) (last - first) > trunc) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
327 char *ffirst = first, *llast = last;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
328 while (1) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
329 /* Select pivot */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
330 {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
331 char *mid = first + size * ((last - first) / size >> 1);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
332 Pivot(SWAP_nonaligned, size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
333 memcpy(pivot, mid, size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
334 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
335 /* Partition. */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
336 Partition(SWAP_nonaligned, size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
337 /* Prepare to recurse/iterate. */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
338 Recurse(trunc)}
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
339 }
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
340 PreInsertion(SWAP_nonaligned, TRUNC_nonaligned, size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
341 Insertion(SWAP_nonaligned);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
342 free(pivot);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
343 }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
344
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
345 static void
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
346 qsort_aligned(void *base, size_t nmemb, size_t size,
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
347 int (*compare) (const void *, const void *))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
348 {
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
349
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
350 stack_entry stack[STACK_SIZE];
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
351 int stacktop = 0;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
352 char *first, *last;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
353 char *pivot = malloc(size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
354 size_t trunc = TRUNC_aligned * size;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
355 assert(pivot != 0);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
356
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
357 first = (char *) base;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
358 last = first + (nmemb - 1) * size;
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
359
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
360 if ((size_t) (last - first) > trunc) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
361 char *ffirst = first, *llast = last;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
362 while (1) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
363 /* Select pivot */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
364 {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
365 char *mid = first + size * ((last - first) / size >> 1);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
366 Pivot(SWAP_aligned, size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
367 memcpy(pivot, mid, size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
368 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
369 /* Partition. */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
370 Partition(SWAP_aligned, size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
371 /* Prepare to recurse/iterate. */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
372 Recurse(trunc)}
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
373 }
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
374 PreInsertion(SWAP_aligned, TRUNC_aligned, size);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
375 Insertion(SWAP_aligned);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
376 free(pivot);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
377 }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
378
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
379 static void
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
380 qsort_words(void *base, size_t nmemb,
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
381 int (*compare) (const void *, const void *))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
382 {
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
383
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
384 stack_entry stack[STACK_SIZE];
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
385 int stacktop = 0;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
386 char *first, *last;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
387 char *pivot = malloc(WORD_BYTES);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
388 assert(pivot != 0);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
389
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
390 first = (char *) base;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
391 last = first + (nmemb - 1) * WORD_BYTES;
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
392
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
393 if (last - first > TRUNC_words) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
394 char *ffirst = first, *llast = last;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
395 while (1) {
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
396 #ifdef DEBUG_QSORT
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
397 fprintf(stderr, "Doing %d:%d: ",
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
398 (first - (char *) base) / WORD_BYTES,
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
399 (last - (char *) base) / WORD_BYTES);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
400 #endif
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
401 /* Select pivot */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
402 {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
403 char *mid =
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
404 first + WORD_BYTES * ((last - first) / (2 * WORD_BYTES));
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
405 Pivot(SWAP_words, WORD_BYTES);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
406 *(int *) pivot = *(int *) mid;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
407 }
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
408 #ifdef DEBUG_QSORT
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
409 fprintf(stderr, "pivot=%d\n", *(int *) pivot);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
410 #endif
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
411 /* Partition. */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
412 Partition(SWAP_words, WORD_BYTES);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
413 /* Prepare to recurse/iterate. */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
414 Recurse(TRUNC_words)}
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
415 }
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
416 PreInsertion(SWAP_words, (TRUNC_words / WORD_BYTES), WORD_BYTES);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
417 /* Now do insertion sort. */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
418 last = ((char *) base) + nmemb * WORD_BYTES;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
419 for (first = ((char *) base) + WORD_BYTES; first != last;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
420 first += WORD_BYTES) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
421 /* Find the right place for |first|. My apologies for var reuse */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
422 int *pl = (int *) (first - WORD_BYTES), *pr = (int *) first;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
423 *(int *) pivot = *(int *) first;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
424 for (; compare(pl, pivot) > 0; pr = pl, --pl) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
425 *pr = *pl;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
426 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
427 if (pr != (int *) first)
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
428 *pr = *(int *) pivot;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
429 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
430 free(pivot);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
431 }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
432
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
433 /* ---------------------------------------------------------------------- */
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
434
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
435 void
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
436 qsort(void *base, size_t nmemb, size_t size,
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
437 int (*compare) (const void *, const void *))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
438 {
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
439
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
440 if (nmemb <= 1)
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
441 return;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
442 if (((uintptr_t) base | size) & (WORD_BYTES - 1))
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
443 qsort_nonaligned(base, nmemb, size, compare);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
444 else if (size != WORD_BYTES)
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
445 qsort_aligned(base, nmemb, size, compare);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
446 else
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
447 qsort_words(base, nmemb, compare);
1330
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
448 }
450721ad5436 It's now possible to build SDL without any C runtime at all on Windows,
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
449
1331
1cbaeee565b1 A few fixes to get this building on Linux again
Sam Lantinga <slouken@libsdl.org>
parents: 1330
diff changeset
450 #endif /* !HAVE_QSORT */
1895
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
Sam Lantinga <slouken@libsdl.org>
parents: 1456
diff changeset
451 /* vi: set ts=4 sw=4 expandtab: */