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1/* pp_sort.c
2 *
4bb101f2 3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
241d1a3b 4 * 2000, 2001, 2002, 2003, 2004, 2005, by Larry Wall and others
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5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
8 *
9 */
10
11/*
12 * ...they shuffled back towards the rear of the line. 'No, not at the
13 * rear!' the slave-driver shouted. 'Three files up. And stay there...
14 */
15
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16/* This file contains pp ("push/pop") functions that
17 * execute the opcodes that make up a perl program. A typical pp function
18 * expects to find its arguments on the stack, and usually pushes its
19 * results onto the stack, hence the 'pp' terminology. Each OP structure
20 * contains a pointer to the relevant pp_foo() function.
21 *
22 * This particular file just contains pp_sort(), which is complex
23 * enough to merit its own file! See the other pp*.c files for the rest of
24 * the pp_ functions.
25 */
26
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27#include "EXTERN.h"
28#define PERL_IN_PP_SORT_C
29#include "perl.h"
30
42165d27
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31#if defined(UNDER_CE)
32/* looks like 'small' is reserved word for WINCE (or somesuch)*/
33#define small xsmall
34#endif
35
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36static I32 sortcv(pTHX_ SV *a, SV *b);
37static I32 sortcv_stacked(pTHX_ SV *a, SV *b);
38static I32 sortcv_xsub(pTHX_ SV *a, SV *b);
39static I32 sv_ncmp(pTHX_ SV *a, SV *b);
40static I32 sv_i_ncmp(pTHX_ SV *a, SV *b);
41static I32 amagic_ncmp(pTHX_ SV *a, SV *b);
42static I32 amagic_i_ncmp(pTHX_ SV *a, SV *b);
43static I32 amagic_cmp(pTHX_ SV *a, SV *b);
44static I32 amagic_cmp_locale(pTHX_ SV *a, SV *b);
45
46#define sv_cmp_static Perl_sv_cmp
47#define sv_cmp_locale_static Perl_sv_cmp_locale
48
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49#define SORTHINTS(hintsv) \
50 (((hintsv) = GvSV(gv_fetchpv("sort::hints", GV_ADDMULTI, SVt_IV))), \
51 (SvIOK(hintsv) ? ((I32)SvIV(hintsv)) : 0))
84d4ea48 52
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53#ifndef SMALLSORT
54#define SMALLSORT (200)
55#endif
56
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57/*
58 * The mergesort implementation is by Peter M. Mcilroy <pmcilroy@lucent.com>.
59 *
60 * The original code was written in conjunction with BSD Computer Software
61 * Research Group at University of California, Berkeley.
62 *
63 * See also: "Optimistic Merge Sort" (SODA '92)
64 *
65 * The integration to Perl is by John P. Linderman <jpl@research.att.com>.
66 *
67 * The code can be distributed under the same terms as Perl itself.
68 *
69 */
70
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71
72typedef char * aptr; /* pointer for arithmetic on sizes */
73typedef SV * gptr; /* pointers in our lists */
74
75/* Binary merge internal sort, with a few special mods
76** for the special perl environment it now finds itself in.
77**
78** Things that were once options have been hotwired
79** to values suitable for this use. In particular, we'll always
80** initialize looking for natural runs, we'll always produce stable
81** output, and we'll always do Peter McIlroy's binary merge.
82*/
83
84/* Pointer types for arithmetic and storage and convenience casts */
85
86#define APTR(P) ((aptr)(P))
87#define GPTP(P) ((gptr *)(P))
88#define GPPP(P) ((gptr **)(P))
89
90
91/* byte offset from pointer P to (larger) pointer Q */
92#define BYTEOFF(P, Q) (APTR(Q) - APTR(P))
93
94#define PSIZE sizeof(gptr)
95
96/* If PSIZE is power of 2, make PSHIFT that power, if that helps */
97
98#ifdef PSHIFT
99#define PNELEM(P, Q) (BYTEOFF(P,Q) >> (PSHIFT))
100#define PNBYTE(N) ((N) << (PSHIFT))
101#define PINDEX(P, N) (GPTP(APTR(P) + PNBYTE(N)))
102#else
103/* Leave optimization to compiler */
104#define PNELEM(P, Q) (GPTP(Q) - GPTP(P))
105#define PNBYTE(N) ((N) * (PSIZE))
106#define PINDEX(P, N) (GPTP(P) + (N))
107#endif
108
109/* Pointer into other corresponding to pointer into this */
110#define POTHER(P, THIS, OTHER) GPTP(APTR(OTHER) + BYTEOFF(THIS,P))
111
112#define FROMTOUPTO(src, dst, lim) do *dst++ = *src++; while(src<lim)
113
114
115/* Runs are identified by a pointer in the auxilliary list.
116** The pointer is at the start of the list,
117** and it points to the start of the next list.
118** NEXT is used as an lvalue, too.
119*/
120
121#define NEXT(P) (*GPPP(P))
122
123
124/* PTHRESH is the minimum number of pairs with the same sense to justify
125** checking for a run and extending it. Note that PTHRESH counts PAIRS,
126** not just elements, so PTHRESH == 8 means a run of 16.
127*/
128
129#define PTHRESH (8)
130
131/* RTHRESH is the number of elements in a run that must compare low
132** to the low element from the opposing run before we justify
133** doing a binary rampup instead of single stepping.
134** In random input, N in a row low should only happen with
135** probability 2^(1-N), so we can risk that we are dealing
136** with orderly input without paying much when we aren't.
137*/
138
139#define RTHRESH (6)
140
141
142/*
143** Overview of algorithm and variables.
144** The array of elements at list1 will be organized into runs of length 2,
145** or runs of length >= 2 * PTHRESH. We only try to form long runs when
146** PTHRESH adjacent pairs compare in the same way, suggesting overall order.
147**
148** Unless otherwise specified, pair pointers address the first of two elements.
149**
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150** b and b+1 are a pair that compare with sense "sense".
151** b is the "bottom" of adjacent pairs that might form a longer run.
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152**
153** p2 parallels b in the list2 array, where runs are defined by
154** a pointer chain.
155**
a0288114 156** t represents the "top" of the adjacent pairs that might extend
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157** the run beginning at b. Usually, t addresses a pair
158** that compares with opposite sense from (b,b+1).
159** However, it may also address a singleton element at the end of list1,
a0288114 160** or it may be equal to "last", the first element beyond list1.
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161**
162** r addresses the Nth pair following b. If this would be beyond t,
163** we back it off to t. Only when r is less than t do we consider the
164** run long enough to consider checking.
165**
166** q addresses a pair such that the pairs at b through q already form a run.
167** Often, q will equal b, indicating we only are sure of the pair itself.
168** However, a search on the previous cycle may have revealed a longer run,
169** so q may be greater than b.
170**
171** p is used to work back from a candidate r, trying to reach q,
172** which would mean b through r would be a run. If we discover such a run,
173** we start q at r and try to push it further towards t.
174** If b through r is NOT a run, we detect the wrong order at (p-1,p).
175** In any event, after the check (if any), we have two main cases.
176**
177** 1) Short run. b <= q < p <= r <= t.
178** b through q is a run (perhaps trivial)
179** q through p are uninteresting pairs
180** p through r is a run
181**
182** 2) Long run. b < r <= q < t.
183** b through q is a run (of length >= 2 * PTHRESH)
184**
185** Note that degenerate cases are not only possible, but likely.
186** For example, if the pair following b compares with opposite sense,
187** then b == q < p == r == t.
188*/
189
190
957d8989 191static IV
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192dynprep(pTHX_ gptr *list1, gptr *list2, size_t nmemb, SVCOMPARE_t cmp)
193{
957d8989 194 I32 sense;
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195 register gptr *b, *p, *q, *t, *p2;
196 register gptr c, *last, *r;
197 gptr *savep;
957d8989 198 IV runs = 0;
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199
200 b = list1;
201 last = PINDEX(b, nmemb);
202 sense = (cmp(aTHX_ *b, *(b+1)) > 0);
203 for (p2 = list2; b < last; ) {
204 /* We just started, or just reversed sense.
205 ** Set t at end of pairs with the prevailing sense.
206 */
207 for (p = b+2, t = p; ++p < last; t = ++p) {
208 if ((cmp(aTHX_ *t, *p) > 0) != sense) break;
209 }
210 q = b;
211 /* Having laid out the playing field, look for long runs */
212 do {
213 p = r = b + (2 * PTHRESH);
214 if (r >= t) p = r = t; /* too short to care about */
215 else {
216 while (((cmp(aTHX_ *(p-1), *p) > 0) == sense) &&
217 ((p -= 2) > q));
218 if (p <= q) {
219 /* b through r is a (long) run.
220 ** Extend it as far as possible.
221 */
222 p = q = r;
223 while (((p += 2) < t) &&
224 ((cmp(aTHX_ *(p-1), *p) > 0) == sense)) q = p;
225 r = p = q + 2; /* no simple pairs, no after-run */
226 }
227 }
228 if (q > b) { /* run of greater than 2 at b */
229 savep = p;
230 p = q += 2;
231 /* pick up singleton, if possible */
232 if ((p == t) &&
233 ((t + 1) == last) &&
234 ((cmp(aTHX_ *(p-1), *p) > 0) == sense))
235 savep = r = p = q = last;
957d8989 236 p2 = NEXT(p2) = p2 + (p - b); ++runs;
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237 if (sense) while (b < --p) {
238 c = *b;
239 *b++ = *p;
240 *p = c;
241 }
242 p = savep;
243 }
244 while (q < p) { /* simple pairs */
957d8989 245 p2 = NEXT(p2) = p2 + 2; ++runs;
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246 if (sense) {
247 c = *q++;
248 *(q-1) = *q;
249 *q++ = c;
250 } else q += 2;
251 }
252 if (((b = p) == t) && ((t+1) == last)) {
957d8989 253 NEXT(p2) = p2 + 1; ++runs;
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254 b++;
255 }
256 q = r;
257 } while (b < t);
258 sense = !sense;
259 }
957d8989 260 return runs;
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261}
262
263
3fe0b9a9 264/* The original merge sort, in use since 5.7, was as fast as, or faster than,
957d8989 265 * qsort on many platforms, but slower than qsort, conspicuously so,
3fe0b9a9 266 * on others. The most likely explanation was platform-specific
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267 * differences in cache sizes and relative speeds.
268 *
269 * The quicksort divide-and-conquer algorithm guarantees that, as the
270 * problem is subdivided into smaller and smaller parts, the parts
271 * fit into smaller (and faster) caches. So it doesn't matter how
272 * many levels of cache exist, quicksort will "find" them, and,
273 * as long as smaller is faster, take advanatge of them.
274 *
3fe0b9a9 275 * By contrast, consider how the original mergesort algorithm worked.
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276 * Suppose we have five runs (each typically of length 2 after dynprep).
277 *
278 * pass base aux
279 * 0 1 2 3 4 5
280 * 1 12 34 5
281 * 2 1234 5
282 * 3 12345
283 * 4 12345
284 *
285 * Adjacent pairs are merged in "grand sweeps" through the input.
286 * This means, on pass 1, the records in runs 1 and 2 aren't revisited until
287 * runs 3 and 4 are merged and the runs from run 5 have been copied.
288 * The only cache that matters is one large enough to hold *all* the input.
289 * On some platforms, this may be many times slower than smaller caches.
290 *
291 * The following pseudo-code uses the same basic merge algorithm,
292 * but in a divide-and-conquer way.
293 *
294 * # merge $runs runs at offset $offset of list $list1 into $list2.
295 * # all unmerged runs ($runs == 1) originate in list $base.
296 * sub mgsort2 {
297 * my ($offset, $runs, $base, $list1, $list2) = @_;
298 *
299 * if ($runs == 1) {
300 * if ($list1 is $base) copy run to $list2
301 * return offset of end of list (or copy)
302 * } else {
303 * $off2 = mgsort2($offset, $runs-($runs/2), $base, $list2, $list1)
304 * mgsort2($off2, $runs/2, $base, $list2, $list1)
305 * merge the adjacent runs at $offset of $list1 into $list2
306 * return the offset of the end of the merged runs
307 * }
308 * }
309 * mgsort2(0, $runs, $base, $aux, $base);
310 *
311 * For our 5 runs, the tree of calls looks like
312 *
313 * 5
314 * 3 2
315 * 2 1 1 1
316 * 1 1
317 *
318 * 1 2 3 4 5
319 *
320 * and the corresponding activity looks like
321 *
322 * copy runs 1 and 2 from base to aux
323 * merge runs 1 and 2 from aux to base
324 * (run 3 is where it belongs, no copy needed)
325 * merge runs 12 and 3 from base to aux
326 * (runs 4 and 5 are where they belong, no copy needed)
327 * merge runs 4 and 5 from base to aux
328 * merge runs 123 and 45 from aux to base
329 *
330 * Note that we merge runs 1 and 2 immediately after copying them,
331 * while they are still likely to be in fast cache. Similarly,
332 * run 3 is merged with run 12 while it still may be lingering in cache.
333 * This implementation should therefore enjoy much of the cache-friendly
334 * behavior that quicksort does. In addition, it does less copying
335 * than the original mergesort implementation (only runs 1 and 2 are copied)
336 * and the "balancing" of merges is better (merged runs comprise more nearly
337 * equal numbers of original runs).
338 *
339 * The actual cache-friendly implementation will use a pseudo-stack
340 * to avoid recursion, and will unroll processing of runs of length 2,
341 * but it is otherwise similar to the recursive implementation.
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342 */
343
344typedef struct {
345 IV offset; /* offset of 1st of 2 runs at this level */
346 IV runs; /* how many runs must be combined into 1 */
347} off_runs; /* pseudo-stack element */
348
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349
350static I32
351cmp_desc(pTHX_ gptr a, gptr b)
352{
353 return -PL_sort_RealCmp(aTHX_ a, b);
354}
355
957d8989 356STATIC void
6c3fb703 357S_mergesortsv(pTHX_ gptr *base, size_t nmemb, SVCOMPARE_t cmp, U32 flags)
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358{
359 IV i, run, runs, offset;
360 I32 sense, level;
361 int iwhich;
362 register gptr *f1, *f2, *t, *b, *p, *tp2, *l1, *l2, *q;
363 gptr *aux, *list1, *list2;
364 gptr *p1;
365 gptr small[SMALLSORT];
366 gptr *which[3];
367 off_runs stack[60], *stackp;
a80036c6 368 SVCOMPARE_t savecmp = 0;
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369
370 if (nmemb <= 1) return; /* sorted trivially */
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371
372 if (flags) {
373 savecmp = PL_sort_RealCmp; /* Save current comparison routine, if any */
374 PL_sort_RealCmp = cmp; /* Put comparison routine where cmp_desc can find it */
375 cmp = cmp_desc;
376 }
377
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378 if (nmemb <= SMALLSORT) aux = small; /* use stack for aux array */
379 else { New(799,aux,nmemb,gptr); } /* allocate auxilliary array */
380 level = 0;
381 stackp = stack;
382 stackp->runs = dynprep(aTHX_ base, aux, nmemb, cmp);
383 stackp->offset = offset = 0;
384 which[0] = which[2] = base;
385 which[1] = aux;
386 for (;;) {
387 /* On levels where both runs have be constructed (stackp->runs == 0),
388 * merge them, and note the offset of their end, in case the offset
389 * is needed at the next level up. Hop up a level, and,
390 * as long as stackp->runs is 0, keep merging.
391 */
392 if ((runs = stackp->runs) == 0) {
393 iwhich = level & 1;
394 list1 = which[iwhich]; /* area where runs are now */
395 list2 = which[++iwhich]; /* area for merged runs */
396 do {
397 offset = stackp->offset;
398 f1 = p1 = list1 + offset; /* start of first run */
399 p = tp2 = list2 + offset; /* where merged run will go */
400 t = NEXT(p); /* where first run ends */
401 f2 = l1 = POTHER(t, list2, list1); /* ... on the other side */
402 t = NEXT(t); /* where second runs ends */
403 l2 = POTHER(t, list2, list1); /* ... on the other side */
404 offset = PNELEM(list2, t);
405 while (f1 < l1 && f2 < l2) {
406 /* If head 1 is larger than head 2, find ALL the elements
407 ** in list 2 strictly less than head1, write them all,
408 ** then head 1. Then compare the new heads, and repeat,
409 ** until one or both lists are exhausted.
410 **
411 ** In all comparisons (after establishing
412 ** which head to merge) the item to merge
413 ** (at pointer q) is the first operand of
414 ** the comparison. When we want to know
a0288114 415 ** if "q is strictly less than the other",
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416 ** we can't just do
417 ** cmp(q, other) < 0
418 ** because stability demands that we treat equality
419 ** as high when q comes from l2, and as low when
420 ** q was from l1. So we ask the question by doing
421 ** cmp(q, other) <= sense
422 ** and make sense == 0 when equality should look low,
423 ** and -1 when equality should look high.
424 */
425
426
427 if (cmp(aTHX_ *f1, *f2) <= 0) {
428 q = f2; b = f1; t = l1;
429 sense = -1;
430 } else {
431 q = f1; b = f2; t = l2;
432 sense = 0;
433 }
434
435
436 /* ramp up
437 **
438 ** Leave t at something strictly
439 ** greater than q (or at the end of the list),
440 ** and b at something strictly less than q.
441 */
442 for (i = 1, run = 0 ;;) {
443 if ((p = PINDEX(b, i)) >= t) {
444 /* off the end */
445 if (((p = PINDEX(t, -1)) > b) &&
446 (cmp(aTHX_ *q, *p) <= sense))
447 t = p;
448 else b = p;
449 break;
450 } else if (cmp(aTHX_ *q, *p) <= sense) {
451 t = p;
452 break;
453 } else b = p;
454 if (++run >= RTHRESH) i += i;
455 }
456
457
458 /* q is known to follow b and must be inserted before t.
459 ** Increment b, so the range of possibilities is [b,t).
460 ** Round binary split down, to favor early appearance.
461 ** Adjust b and t until q belongs just before t.
462 */
463
464 b++;
465 while (b < t) {
466 p = PINDEX(b, (PNELEM(b, t) - 1) / 2);
467 if (cmp(aTHX_ *q, *p) <= sense) {
468 t = p;
469 } else b = p + 1;
470 }
471
472
473 /* Copy all the strictly low elements */
474
475 if (q == f1) {
476 FROMTOUPTO(f2, tp2, t);
477 *tp2++ = *f1++;
478 } else {
479 FROMTOUPTO(f1, tp2, t);
480 *tp2++ = *f2++;
481 }
482 }
483
484
485 /* Run out remaining list */
486 if (f1 == l1) {
487 if (f2 < l2) FROMTOUPTO(f2, tp2, l2);
488 } else FROMTOUPTO(f1, tp2, l1);
489 p1 = NEXT(p1) = POTHER(tp2, list2, list1);
490
491 if (--level == 0) goto done;
492 --stackp;
493 t = list1; list1 = list2; list2 = t; /* swap lists */
494 } while ((runs = stackp->runs) == 0);
495 }
496
497
498 stackp->runs = 0; /* current run will finish level */
499 /* While there are more than 2 runs remaining,
500 * turn them into exactly 2 runs (at the "other" level),
501 * each made up of approximately half the runs.
502 * Stack the second half for later processing,
503 * and set about producing the first half now.
504 */
505 while (runs > 2) {
506 ++level;
507 ++stackp;
508 stackp->offset = offset;
509 runs -= stackp->runs = runs / 2;
510 }
511 /* We must construct a single run from 1 or 2 runs.
512 * All the original runs are in which[0] == base.
513 * The run we construct must end up in which[level&1].
514 */
515 iwhich = level & 1;
516 if (runs == 1) {
517 /* Constructing a single run from a single run.
518 * If it's where it belongs already, there's nothing to do.
519 * Otherwise, copy it to where it belongs.
520 * A run of 1 is either a singleton at level 0,
521 * or the second half of a split 3. In neither event
522 * is it necessary to set offset. It will be set by the merge
523 * that immediately follows.
524 */
525 if (iwhich) { /* Belongs in aux, currently in base */
526 f1 = b = PINDEX(base, offset); /* where list starts */
527 f2 = PINDEX(aux, offset); /* where list goes */
528 t = NEXT(f2); /* where list will end */
529 offset = PNELEM(aux, t); /* offset thereof */
530 t = PINDEX(base, offset); /* where it currently ends */
531 FROMTOUPTO(f1, f2, t); /* copy */
532 NEXT(b) = t; /* set up parallel pointer */
533 } else if (level == 0) goto done; /* single run at level 0 */
534 } else {
535 /* Constructing a single run from two runs.
536 * The merge code at the top will do that.
537 * We need only make sure the two runs are in the "other" array,
538 * so they'll end up in the correct array after the merge.
539 */
540 ++level;
541 ++stackp;
542 stackp->offset = offset;
543 stackp->runs = 0; /* take care of both runs, trigger merge */
544 if (!iwhich) { /* Merged runs belong in aux, copy 1st */
545 f1 = b = PINDEX(base, offset); /* where first run starts */
546 f2 = PINDEX(aux, offset); /* where it will be copied */
547 t = NEXT(f2); /* where first run will end */
548 offset = PNELEM(aux, t); /* offset thereof */
549 p = PINDEX(base, offset); /* end of first run */
550 t = NEXT(t); /* where second run will end */
551 t = PINDEX(base, PNELEM(aux, t)); /* where it now ends */
552 FROMTOUPTO(f1, f2, t); /* copy both runs */
553 NEXT(b) = p; /* paralled pointer for 1st */
554 NEXT(p) = t; /* ... and for second */
555 }
556 }
557 }
558done:
559 if (aux != small) Safefree(aux); /* free iff allocated */
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560 if (flags) {
561 PL_sort_RealCmp = savecmp; /* Restore current comparison routine, if any */
562 }
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563 return;
564}
565
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566/*
567 * The quicksort implementation was derived from source code contributed
568 * by Tom Horsley.
569 *
570 * NOTE: this code was derived from Tom Horsley's qsort replacement
571 * and should not be confused with the original code.
572 */
573
574/* Copyright (C) Tom Horsley, 1997. All rights reserved.
575
576 Permission granted to distribute under the same terms as perl which are
577 (briefly):
578
579 This program is free software; you can redistribute it and/or modify
580 it under the terms of either:
581
582 a) the GNU General Public License as published by the Free
583 Software Foundation; either version 1, or (at your option) any
584 later version, or
585
586 b) the "Artistic License" which comes with this Kit.
587
588 Details on the perl license can be found in the perl source code which
589 may be located via the www.perl.com web page.
590
591 This is the most wonderfulest possible qsort I can come up with (and
592 still be mostly portable) My (limited) tests indicate it consistently
593 does about 20% fewer calls to compare than does the qsort in the Visual
594 C++ library, other vendors may vary.
595
596 Some of the ideas in here can be found in "Algorithms" by Sedgewick,
597 others I invented myself (or more likely re-invented since they seemed
598 pretty obvious once I watched the algorithm operate for a while).
599
600 Most of this code was written while watching the Marlins sweep the Giants
601 in the 1997 National League Playoffs - no Braves fans allowed to use this
602 code (just kidding :-).
603
604 I realize that if I wanted to be true to the perl tradition, the only
605 comment in this file would be something like:
606
607 ...they shuffled back towards the rear of the line. 'No, not at the
608 rear!' the slave-driver shouted. 'Three files up. And stay there...
609
610 However, I really needed to violate that tradition just so I could keep
611 track of what happens myself, not to mention some poor fool trying to
612 understand this years from now :-).
613*/
614
615/* ********************************************************** Configuration */
616
617#ifndef QSORT_ORDER_GUESS
618#define QSORT_ORDER_GUESS 2 /* Select doubling version of the netBSD trick */
619#endif
620
621/* QSORT_MAX_STACK is the largest number of partitions that can be stacked up for
622 future processing - a good max upper bound is log base 2 of memory size
623 (32 on 32 bit machines, 64 on 64 bit machines, etc). In reality can
624 safely be smaller than that since the program is taking up some space and
625 most operating systems only let you grab some subset of contiguous
626 memory (not to mention that you are normally sorting data larger than
627 1 byte element size :-).
628*/
629#ifndef QSORT_MAX_STACK
630#define QSORT_MAX_STACK 32
631#endif
632
633/* QSORT_BREAK_EVEN is the size of the largest partition we should insertion sort.
634 Anything bigger and we use qsort. If you make this too small, the qsort
635 will probably break (or become less efficient), because it doesn't expect
636 the middle element of a partition to be the same as the right or left -
637 you have been warned).
638*/
639#ifndef QSORT_BREAK_EVEN
640#define QSORT_BREAK_EVEN 6
641#endif
642
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643/* QSORT_PLAY_SAFE is the size of the largest partition we're willing
644 to go quadratic on. We innoculate larger partitions against
645 quadratic behavior by shuffling them before sorting. This is not
646 an absolute guarantee of non-quadratic behavior, but it would take
647 staggeringly bad luck to pick extreme elements as the pivot
648 from randomized data.
649*/
650#ifndef QSORT_PLAY_SAFE
651#define QSORT_PLAY_SAFE 255
652#endif
653
84d4ea48
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654/* ************************************************************* Data Types */
655
656/* hold left and right index values of a partition waiting to be sorted (the
657 partition includes both left and right - right is NOT one past the end or
658 anything like that).
659*/
660struct partition_stack_entry {
661 int left;
662 int right;
663#ifdef QSORT_ORDER_GUESS
664 int qsort_break_even;
665#endif
666};
667
668/* ******************************************************* Shorthand Macros */
669
670/* Note that these macros will be used from inside the qsort function where
671 we happen to know that the variable 'elt_size' contains the size of an
672 array element and the variable 'temp' points to enough space to hold a
673 temp element and the variable 'array' points to the array being sorted
674 and 'compare' is the pointer to the compare routine.
675
676 Also note that there are very many highly architecture specific ways
677 these might be sped up, but this is simply the most generally portable
678 code I could think of.
679*/
680
681/* Return < 0 == 0 or > 0 as the value of elt1 is < elt2, == elt2, > elt2
682*/
683#define qsort_cmp(elt1, elt2) \
684 ((*compare)(aTHX_ array[elt1], array[elt2]))
685
686#ifdef QSORT_ORDER_GUESS
687#define QSORT_NOTICE_SWAP swapped++;
688#else
689#define QSORT_NOTICE_SWAP
690#endif
691
692/* swaps contents of array elements elt1, elt2.
693*/
694#define qsort_swap(elt1, elt2) \
695 STMT_START { \
696 QSORT_NOTICE_SWAP \
697 temp = array[elt1]; \
698 array[elt1] = array[elt2]; \
699 array[elt2] = temp; \
700 } STMT_END
701
702/* rotate contents of elt1, elt2, elt3 such that elt1 gets elt2, elt2 gets
703 elt3 and elt3 gets elt1.
704*/
705#define qsort_rotate(elt1, elt2, elt3) \
706 STMT_START { \
707 QSORT_NOTICE_SWAP \
708 temp = array[elt1]; \
709 array[elt1] = array[elt2]; \
710 array[elt2] = array[elt3]; \
711 array[elt3] = temp; \
712 } STMT_END
713
714/* ************************************************************ Debug stuff */
715
716#ifdef QSORT_DEBUG
717
718static void
719break_here()
720{
721 return; /* good place to set a breakpoint */
722}
723
724#define qsort_assert(t) (void)( (t) || (break_here(), 0) )
725
726static void
727doqsort_all_asserts(
728 void * array,
729 size_t num_elts,
730 size_t elt_size,
731 int (*compare)(const void * elt1, const void * elt2),
732 int pc_left, int pc_right, int u_left, int u_right)
733{
734 int i;
735
736 qsort_assert(pc_left <= pc_right);
737 qsort_assert(u_right < pc_left);
738 qsort_assert(pc_right < u_left);
739 for (i = u_right + 1; i < pc_left; ++i) {
740 qsort_assert(qsort_cmp(i, pc_left) < 0);
741 }
742 for (i = pc_left; i < pc_right; ++i) {
743 qsort_assert(qsort_cmp(i, pc_right) == 0);
744 }
745 for (i = pc_right + 1; i < u_left; ++i) {
746 qsort_assert(qsort_cmp(pc_right, i) < 0);
747 }
748}
749
750#define qsort_all_asserts(PC_LEFT, PC_RIGHT, U_LEFT, U_RIGHT) \
751 doqsort_all_asserts(array, num_elts, elt_size, compare, \
752 PC_LEFT, PC_RIGHT, U_LEFT, U_RIGHT)
753
754#else
755
756#define qsort_assert(t) ((void)0)
757
758#define qsort_all_asserts(PC_LEFT, PC_RIGHT, U_LEFT, U_RIGHT) ((void)0)
759
760#endif
761
762/* ****************************************************************** qsort */
763
764STATIC void /* the standard unstable (u) quicksort (qsort) */
765S_qsortsvu(pTHX_ SV ** array, size_t num_elts, SVCOMPARE_t compare)
766{
767 register SV * temp;
768
769 struct partition_stack_entry partition_stack[QSORT_MAX_STACK];
770 int next_stack_entry = 0;
771
772 int part_left;
773 int part_right;
774#ifdef QSORT_ORDER_GUESS
775 int qsort_break_even;
776 int swapped;
777#endif
778
779 /* Make sure we actually have work to do.
780 */
781 if (num_elts <= 1) {
782 return;
783 }
784
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785 /* Innoculate large partitions against quadratic behavior */
786 if (num_elts > QSORT_PLAY_SAFE) {
787 register size_t n, j;
788 register SV **q;
789 for (n = num_elts, q = array; n > 1; ) {
eb160463 790 j = (size_t)(n-- * Drand01());
4eb872f6
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791 temp = q[j];
792 q[j] = q[n];
793 q[n] = temp;
794 }
795 }
796
84d4ea48
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797 /* Setup the initial partition definition and fall into the sorting loop
798 */
799 part_left = 0;
800 part_right = (int)(num_elts - 1);
801#ifdef QSORT_ORDER_GUESS
802 qsort_break_even = QSORT_BREAK_EVEN;
803#else
804#define qsort_break_even QSORT_BREAK_EVEN
805#endif
806 for ( ; ; ) {
807 if ((part_right - part_left) >= qsort_break_even) {
808 /* OK, this is gonna get hairy, so lets try to document all the
809 concepts and abbreviations and variables and what they keep
810 track of:
811
812 pc: pivot chunk - the set of array elements we accumulate in the
813 middle of the partition, all equal in value to the original
814 pivot element selected. The pc is defined by:
815
816 pc_left - the leftmost array index of the pc
817 pc_right - the rightmost array index of the pc
818
819 we start with pc_left == pc_right and only one element
820 in the pivot chunk (but it can grow during the scan).
821
822 u: uncompared elements - the set of elements in the partition
823 we have not yet compared to the pivot value. There are two
824 uncompared sets during the scan - one to the left of the pc
825 and one to the right.
826
827 u_right - the rightmost index of the left side's uncompared set
828 u_left - the leftmost index of the right side's uncompared set
829
830 The leftmost index of the left sides's uncompared set
831 doesn't need its own variable because it is always defined
832 by the leftmost edge of the whole partition (part_left). The
833 same goes for the rightmost edge of the right partition
834 (part_right).
835
836 We know there are no uncompared elements on the left once we
837 get u_right < part_left and no uncompared elements on the
838 right once u_left > part_right. When both these conditions
839 are met, we have completed the scan of the partition.
840
841 Any elements which are between the pivot chunk and the
842 uncompared elements should be less than the pivot value on
843 the left side and greater than the pivot value on the right
844 side (in fact, the goal of the whole algorithm is to arrange
845 for that to be true and make the groups of less-than and
846 greater-then elements into new partitions to sort again).
847
848 As you marvel at the complexity of the code and wonder why it
849 has to be so confusing. Consider some of the things this level
850 of confusion brings:
851
852 Once I do a compare, I squeeze every ounce of juice out of it. I
853 never do compare calls I don't have to do, and I certainly never
854 do redundant calls.
855
856 I also never swap any elements unless I can prove there is a
857 good reason. Many sort algorithms will swap a known value with
858 an uncompared value just to get things in the right place (or
859 avoid complexity :-), but that uncompared value, once it gets
860 compared, may then have to be swapped again. A lot of the
861 complexity of this code is due to the fact that it never swaps
862 anything except compared values, and it only swaps them when the
863 compare shows they are out of position.
864 */
865 int pc_left, pc_right;
866 int u_right, u_left;
867
868 int s;
869
870 pc_left = ((part_left + part_right) / 2);
871 pc_right = pc_left;
872 u_right = pc_left - 1;
873 u_left = pc_right + 1;
874
875 /* Qsort works best when the pivot value is also the median value
876 in the partition (unfortunately you can't find the median value
877 without first sorting :-), so to give the algorithm a helping
878 hand, we pick 3 elements and sort them and use the median value
879 of that tiny set as the pivot value.
880
881 Some versions of qsort like to use the left middle and right as
882 the 3 elements to sort so they can insure the ends of the
883 partition will contain values which will stop the scan in the
884 compare loop, but when you have to call an arbitrarily complex
885 routine to do a compare, its really better to just keep track of
886 array index values to know when you hit the edge of the
887 partition and avoid the extra compare. An even better reason to
888 avoid using a compare call is the fact that you can drop off the
889 edge of the array if someone foolishly provides you with an
890 unstable compare function that doesn't always provide consistent
891 results.
892
893 So, since it is simpler for us to compare the three adjacent
894 elements in the middle of the partition, those are the ones we
895 pick here (conveniently pointed at by u_right, pc_left, and
896 u_left). The values of the left, center, and right elements
897 are refered to as l c and r in the following comments.
898 */
899
900#ifdef QSORT_ORDER_GUESS
901 swapped = 0;
902#endif
903 s = qsort_cmp(u_right, pc_left);
904 if (s < 0) {
905 /* l < c */
906 s = qsort_cmp(pc_left, u_left);
907 /* if l < c, c < r - already in order - nothing to do */
908 if (s == 0) {
909 /* l < c, c == r - already in order, pc grows */
910 ++pc_right;
911 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
912 } else if (s > 0) {
913 /* l < c, c > r - need to know more */
914 s = qsort_cmp(u_right, u_left);
915 if (s < 0) {
916 /* l < c, c > r, l < r - swap c & r to get ordered */
917 qsort_swap(pc_left, u_left);
918 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
919 } else if (s == 0) {
920 /* l < c, c > r, l == r - swap c&r, grow pc */
921 qsort_swap(pc_left, u_left);
922 --pc_left;
923 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
924 } else {
925 /* l < c, c > r, l > r - make lcr into rlc to get ordered */
926 qsort_rotate(pc_left, u_right, u_left);
927 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
928 }
929 }
930 } else if (s == 0) {
931 /* l == c */
932 s = qsort_cmp(pc_left, u_left);
933 if (s < 0) {
934 /* l == c, c < r - already in order, grow pc */
935 --pc_left;
936 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
937 } else if (s == 0) {
938 /* l == c, c == r - already in order, grow pc both ways */
939 --pc_left;
940 ++pc_right;
941 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
942 } else {
943 /* l == c, c > r - swap l & r, grow pc */
944 qsort_swap(u_right, u_left);
945 ++pc_right;
946 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
947 }
948 } else {
949 /* l > c */
950 s = qsort_cmp(pc_left, u_left);
951 if (s < 0) {
952 /* l > c, c < r - need to know more */
953 s = qsort_cmp(u_right, u_left);
954 if (s < 0) {
955 /* l > c, c < r, l < r - swap l & c to get ordered */
956 qsort_swap(u_right, pc_left);
957 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
958 } else if (s == 0) {
959 /* l > c, c < r, l == r - swap l & c, grow pc */
960 qsort_swap(u_right, pc_left);
961 ++pc_right;
962 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
963 } else {
964 /* l > c, c < r, l > r - rotate lcr into crl to order */
965 qsort_rotate(u_right, pc_left, u_left);
966 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
967 }
968 } else if (s == 0) {
969 /* l > c, c == r - swap ends, grow pc */
970 qsort_swap(u_right, u_left);
971 --pc_left;
972 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
973 } else {
974 /* l > c, c > r - swap ends to get in order */
975 qsort_swap(u_right, u_left);
976 qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1);
977 }
978 }
979 /* We now know the 3 middle elements have been compared and
980 arranged in the desired order, so we can shrink the uncompared
981 sets on both sides
982 */
983 --u_right;
984 ++u_left;
985 qsort_all_asserts(pc_left, pc_right, u_left, u_right);
986
987 /* The above massive nested if was the simple part :-). We now have
988 the middle 3 elements ordered and we need to scan through the
989 uncompared sets on either side, swapping elements that are on
990 the wrong side or simply shuffling equal elements around to get
991 all equal elements into the pivot chunk.
992 */
993
994 for ( ; ; ) {
995 int still_work_on_left;
996 int still_work_on_right;
997
998 /* Scan the uncompared values on the left. If I find a value
999 equal to the pivot value, move it over so it is adjacent to
1000 the pivot chunk and expand the pivot chunk. If I find a value
1001 less than the pivot value, then just leave it - its already
1002 on the correct side of the partition. If I find a greater
1003 value, then stop the scan.
1004 */
1005 while ((still_work_on_left = (u_right >= part_left))) {
1006 s = qsort_cmp(u_right, pc_left);
1007 if (s < 0) {
1008 --u_right;
1009 } else if (s == 0) {
1010 --pc_left;
1011 if (pc_left != u_right) {
1012 qsort_swap(u_right, pc_left);
1013 }
1014 --u_right;
1015 } else {
1016 break;
1017 }
1018 qsort_assert(u_right < pc_left);
1019 qsort_assert(pc_left <= pc_right);
1020 qsort_assert(qsort_cmp(u_right + 1, pc_left) <= 0);
1021 qsort_assert(qsort_cmp(pc_left, pc_right) == 0);
1022 }
1023
1024 /* Do a mirror image scan of uncompared values on the right
1025 */
1026 while ((still_work_on_right = (u_left <= part_right))) {
1027 s = qsort_cmp(pc_right, u_left);
1028 if (s < 0) {
1029 ++u_left;
1030 } else if (s == 0) {
1031 ++pc_right;
1032 if (pc_right != u_left) {
1033 qsort_swap(pc_right, u_left);
1034 }
1035 ++u_left;
1036 } else {
1037 break;
1038 }
1039 qsort_assert(u_left > pc_right);
1040 qsort_assert(pc_left <= pc_right);
1041 qsort_assert(qsort_cmp(pc_right, u_left - 1) <= 0);
1042 qsort_assert(qsort_cmp(pc_left, pc_right) == 0);
1043 }
1044
1045 if (still_work_on_left) {
1046 /* I know I have a value on the left side which needs to be
1047 on the right side, but I need to know more to decide
1048 exactly the best thing to do with it.
1049 */
1050 if (still_work_on_right) {
1051 /* I know I have values on both side which are out of
1052 position. This is a big win because I kill two birds
1053 with one swap (so to speak). I can advance the
1054 uncompared pointers on both sides after swapping both
1055 of them into the right place.
1056 */
1057 qsort_swap(u_right, u_left);
1058 --u_right;
1059 ++u_left;
1060 qsort_all_asserts(pc_left, pc_right, u_left, u_right);
1061 } else {
1062 /* I have an out of position value on the left, but the
1063 right is fully scanned, so I "slide" the pivot chunk
1064 and any less-than values left one to make room for the
1065 greater value over on the right. If the out of position
1066 value is immediately adjacent to the pivot chunk (there
1067 are no less-than values), I can do that with a swap,
1068 otherwise, I have to rotate one of the less than values
1069 into the former position of the out of position value
1070 and the right end of the pivot chunk into the left end
1071 (got all that?).
1072 */
1073 --pc_left;
1074 if (pc_left == u_right) {
1075 qsort_swap(u_right, pc_right);
1076 qsort_all_asserts(pc_left, pc_right-1, u_left, u_right-1);
1077 } else {
1078 qsort_rotate(u_right, pc_left, pc_right);
1079 qsort_all_asserts(pc_left, pc_right-1, u_left, u_right-1);
1080 }
1081 --pc_right;
1082 --u_right;
1083 }
1084 } else if (still_work_on_right) {
1085 /* Mirror image of complex case above: I have an out of
1086 position value on the right, but the left is fully
1087 scanned, so I need to shuffle things around to make room
1088 for the right value on the left.
1089 */
1090 ++pc_right;
1091 if (pc_right == u_left) {
1092 qsort_swap(u_left, pc_left);
1093 qsort_all_asserts(pc_left+1, pc_right, u_left+1, u_right);
1094 } else {
1095 qsort_rotate(pc_right, pc_left, u_left);
1096 qsort_all_asserts(pc_left+1, pc_right, u_left+1, u_right);
1097 }
1098 ++pc_left;
1099 ++u_left;
1100 } else {
1101 /* No more scanning required on either side of partition,
1102 break out of loop and figure out next set of partitions
1103 */
1104 break;
1105 }
1106 }
1107
1108 /* The elements in the pivot chunk are now in the right place. They
1109 will never move or be compared again. All I have to do is decide
1110 what to do with the stuff to the left and right of the pivot
1111 chunk.
1112
1113 Notes on the QSORT_ORDER_GUESS ifdef code:
1114
1115 1. If I just built these partitions without swapping any (or
1116 very many) elements, there is a chance that the elements are
1117 already ordered properly (being properly ordered will
1118 certainly result in no swapping, but the converse can't be
1119 proved :-).
1120
1121 2. A (properly written) insertion sort will run faster on
1122 already ordered data than qsort will.
1123
1124 3. Perhaps there is some way to make a good guess about
1125 switching to an insertion sort earlier than partition size 6
1126 (for instance - we could save the partition size on the stack
1127 and increase the size each time we find we didn't swap, thus
1128 switching to insertion sort earlier for partitions with a
1129 history of not swapping).
1130
1131 4. Naturally, if I just switch right away, it will make
1132 artificial benchmarks with pure ascending (or descending)
1133 data look really good, but is that a good reason in general?
1134 Hard to say...
1135 */
1136
1137#ifdef QSORT_ORDER_GUESS
1138 if (swapped < 3) {
1139#if QSORT_ORDER_GUESS == 1
1140 qsort_break_even = (part_right - part_left) + 1;
1141#endif
1142#if QSORT_ORDER_GUESS == 2
1143 qsort_break_even *= 2;
1144#endif
1145#if QSORT_ORDER_GUESS == 3
1146 int prev_break = qsort_break_even;
1147 qsort_break_even *= qsort_break_even;
1148 if (qsort_break_even < prev_break) {
1149 qsort_break_even = (part_right - part_left) + 1;
1150 }
1151#endif
1152 } else {
1153 qsort_break_even = QSORT_BREAK_EVEN;
1154 }
1155#endif
1156
1157 if (part_left < pc_left) {
1158 /* There are elements on the left which need more processing.
1159 Check the right as well before deciding what to do.
1160 */
1161 if (pc_right < part_right) {
1162 /* We have two partitions to be sorted. Stack the biggest one
1163 and process the smallest one on the next iteration. This
1164 minimizes the stack height by insuring that any additional
1165 stack entries must come from the smallest partition which
1166 (because it is smallest) will have the fewest
1167 opportunities to generate additional stack entries.
1168 */
1169 if ((part_right - pc_right) > (pc_left - part_left)) {
1170 /* stack the right partition, process the left */
1171 partition_stack[next_stack_entry].left = pc_right + 1;
1172 partition_stack[next_stack_entry].right = part_right;
1173#ifdef QSORT_ORDER_GUESS
1174 partition_stack[next_stack_entry].qsort_break_even = qsort_break_even;
1175#endif
1176 part_right = pc_left - 1;
1177 } else {
1178 /* stack the left partition, process the right */
1179 partition_stack[next_stack_entry].left = part_left;
1180 partition_stack[next_stack_entry].right = pc_left - 1;
1181#ifdef QSORT_ORDER_GUESS
1182 partition_stack[next_stack_entry].qsort_break_even = qsort_break_even;
1183#endif
1184 part_left = pc_right + 1;
1185 }
1186 qsort_assert(next_stack_entry < QSORT_MAX_STACK);
1187 ++next_stack_entry;
1188 } else {
1189 /* The elements on the left are the only remaining elements
1190 that need sorting, arrange for them to be processed as the
1191 next partition.
1192 */
1193 part_right = pc_left - 1;
1194 }
1195 } else if (pc_right < part_right) {
1196 /* There is only one chunk on the right to be sorted, make it
1197 the new partition and loop back around.
1198 */
1199 part_left = pc_right + 1;
1200 } else {
1201 /* This whole partition wound up in the pivot chunk, so
1202 we need to get a new partition off the stack.
1203 */
1204 if (next_stack_entry == 0) {
1205 /* the stack is empty - we are done */
1206 break;
1207 }
1208 --next_stack_entry;
1209 part_left = partition_stack[next_stack_entry].left;
1210 part_right = partition_stack[next_stack_entry].right;
1211#ifdef QSORT_ORDER_GUESS
1212 qsort_break_even = partition_stack[next_stack_entry].qsort_break_even;
1213#endif
1214 }
1215 } else {
1216 /* This partition is too small to fool with qsort complexity, just
1217 do an ordinary insertion sort to minimize overhead.
1218 */
1219 int i;
1220 /* Assume 1st element is in right place already, and start checking
1221 at 2nd element to see where it should be inserted.
1222 */
1223 for (i = part_left + 1; i <= part_right; ++i) {
1224 int j;
1225 /* Scan (backwards - just in case 'i' is already in right place)
1226 through the elements already sorted to see if the ith element
1227 belongs ahead of one of them.
1228 */
1229 for (j = i - 1; j >= part_left; --j) {
1230 if (qsort_cmp(i, j) >= 0) {
1231 /* i belongs right after j
1232 */
1233 break;
1234 }
1235 }
1236 ++j;
1237 if (j != i) {
1238 /* Looks like we really need to move some things
1239 */
1240 int k;
1241 temp = array[i];
1242 for (k = i - 1; k >= j; --k)
1243 array[k + 1] = array[k];
1244 array[j] = temp;
1245 }
1246 }
1247
1248 /* That partition is now sorted, grab the next one, or get out
1249 of the loop if there aren't any more.
1250 */
1251
1252 if (next_stack_entry == 0) {
1253 /* the stack is empty - we are done */
1254 break;
1255 }
1256 --next_stack_entry;
1257 part_left = partition_stack[next_stack_entry].left;
1258 part_right = partition_stack[next_stack_entry].right;
1259#ifdef QSORT_ORDER_GUESS
1260 qsort_break_even = partition_stack[next_stack_entry].qsort_break_even;
1261#endif
1262 }
1263 }
1264
1265 /* Believe it or not, the array is sorted at this point! */
1266}
1267
84d4ea48
JH
1268/* Stabilize what is, presumably, an otherwise unstable sort method.
1269 * We do that by allocating (or having on hand) an array of pointers
1270 * that is the same size as the original array of elements to be sorted.
1271 * We initialize this parallel array with the addresses of the original
1272 * array elements. This indirection can make you crazy.
1273 * Some pictures can help. After initializing, we have
1274 *
1275 * indir list1
1276 * +----+ +----+
1277 * | | --------------> | | ------> first element to be sorted
1278 * +----+ +----+
1279 * | | --------------> | | ------> second element to be sorted
1280 * +----+ +----+
1281 * | | --------------> | | ------> third element to be sorted
1282 * +----+ +----+
1283 * ...
1284 * +----+ +----+
1285 * | | --------------> | | ------> n-1st element to be sorted
1286 * +----+ +----+
1287 * | | --------------> | | ------> n-th element to be sorted
1288 * +----+ +----+
1289 *
1290 * During the sort phase, we leave the elements of list1 where they are,
1291 * and sort the pointers in the indirect array in the same order determined
1292 * by the original comparison routine on the elements pointed to.
1293 * Because we don't move the elements of list1 around through
1294 * this phase, we can break ties on elements that compare equal
1295 * using their address in the list1 array, ensuring stabilty.
1296 * This leaves us with something looking like
1297 *
1298 * indir list1
1299 * +----+ +----+
1300 * | | --+ +---> | | ------> first element to be sorted
1301 * +----+ | | +----+
1302 * | | --|-------|---> | | ------> second element to be sorted
1303 * +----+ | | +----+
1304 * | | --|-------+ +-> | | ------> third element to be sorted
1305 * +----+ | | +----+
1306 * ...
1307 * +----+ | | | | +----+
1308 * | | ---|-+ | +--> | | ------> n-1st element to be sorted
1309 * +----+ | | +----+
1310 * | | ---+ +----> | | ------> n-th element to be sorted
1311 * +----+ +----+
1312 *
1313 * where the i-th element of the indirect array points to the element
1314 * that should be i-th in the sorted array. After the sort phase,
1315 * we have to put the elements of list1 into the places
1316 * dictated by the indirect array.
1317 */
1318
84d4ea48
JH
1319
1320static I32
1321cmpindir(pTHX_ gptr a, gptr b)
1322{
1323 I32 sense;
1324 gptr *ap = (gptr *)a;
1325 gptr *bp = (gptr *)b;
1326
147f47de 1327 if ((sense = PL_sort_RealCmp(aTHX_ *ap, *bp)) == 0)
84d4ea48
JH
1328 sense = (ap > bp) ? 1 : ((ap < bp) ? -1 : 0);
1329 return sense;
1330}
1331
6c3fb703
NC
1332static I32
1333cmpindir_desc(pTHX_ gptr a, gptr b)
1334{
1335 I32 sense;
1336 gptr *ap = (gptr *)a;
1337 gptr *bp = (gptr *)b;
1338
1339 /* Reverse the default */
1340 if ((sense = PL_sort_RealCmp(aTHX_ *ap, *bp)))
1341 return -sense;
1342 /* But don't reverse the stability test. */
1343 return (ap > bp) ? 1 : ((ap < bp) ? -1 : 0);
1344
1345}
1346
84d4ea48 1347STATIC void
6c3fb703 1348S_qsortsv(pTHX_ gptr *list1, size_t nmemb, SVCOMPARE_t cmp, U32 flags)
84d4ea48 1349{
045ac317 1350 SV *hintsv;
84d4ea48 1351
045ac317 1352 if (SORTHINTS(hintsv) & HINT_SORT_STABLE) {
84d4ea48
JH
1353 register gptr **pp, *q;
1354 register size_t n, j, i;
1355 gptr *small[SMALLSORT], **indir, tmp;
1356 SVCOMPARE_t savecmp;
1357 if (nmemb <= 1) return; /* sorted trivially */
4eb872f6 1358
84d4ea48
JH
1359 /* Small arrays can use the stack, big ones must be allocated */
1360 if (nmemb <= SMALLSORT) indir = small;
1361 else { New(1799, indir, nmemb, gptr *); }
4eb872f6 1362
84d4ea48
JH
1363 /* Copy pointers to original array elements into indirect array */
1364 for (n = nmemb, pp = indir, q = list1; n--; ) *pp++ = q++;
4eb872f6 1365
147f47de
AB
1366 savecmp = PL_sort_RealCmp; /* Save current comparison routine, if any */
1367 PL_sort_RealCmp = cmp; /* Put comparison routine where cmpindir can find it */
4eb872f6 1368
84d4ea48 1369 /* sort, with indirection */
6c3fb703
NC
1370 S_qsortsvu(aTHX_ (gptr *)indir, nmemb,
1371 flags ? cmpindir_desc : cmpindir);
4eb872f6 1372
84d4ea48
JH
1373 pp = indir;
1374 q = list1;
1375 for (n = nmemb; n--; ) {
1376 /* Assert A: all elements of q with index > n are already
1377 * in place. This is vacuosly true at the start, and we
1378 * put element n where it belongs below (if it wasn't
1379 * already where it belonged). Assert B: we only move
1380 * elements that aren't where they belong,
1381 * so, by A, we never tamper with elements above n.
1382 */
1383 j = pp[n] - q; /* This sets j so that q[j] is
1384 * at pp[n]. *pp[j] belongs in
1385 * q[j], by construction.
1386 */
1387 if (n != j) { /* all's well if n == j */
1388 tmp = q[j]; /* save what's in q[j] */
1389 do {
1390 q[j] = *pp[j]; /* put *pp[j] where it belongs */
1391 i = pp[j] - q; /* the index in q of the element
1392 * just moved */
1393 pp[j] = q + j; /* this is ok now */
1394 } while ((j = i) != n);
1395 /* There are only finitely many (nmemb) addresses
1396 * in the pp array.
1397 * So we must eventually revisit an index we saw before.
1398 * Suppose the first revisited index is k != n.
1399 * An index is visited because something else belongs there.
1400 * If we visit k twice, then two different elements must
1401 * belong in the same place, which cannot be.
1402 * So j must get back to n, the loop terminates,
1403 * and we put the saved element where it belongs.
1404 */
1405 q[n] = tmp; /* put what belongs into
1406 * the n-th element */
1407 }
1408 }
1409
1410 /* free iff allocated */
1411 if (indir != small) { Safefree(indir); }
1412 /* restore prevailing comparison routine */
147f47de 1413 PL_sort_RealCmp = savecmp;
6c3fb703
NC
1414 } else if (flags) {
1415 SVCOMPARE_t savecmp = PL_sort_RealCmp; /* Save current comparison routine, if any */
1416 PL_sort_RealCmp = cmp; /* Put comparison routine where cmp_desc can find it */
1417 cmp = cmp_desc;
1418 S_qsortsvu(aTHX_ list1, nmemb, cmp);
1419 /* restore prevailing comparison routine */
1420 PL_sort_RealCmp = savecmp;
c53fc8a6
JH
1421 } else {
1422 S_qsortsvu(aTHX_ list1, nmemb, cmp);
84d4ea48
JH
1423 }
1424}
4eb872f6
JL
1425
1426/*
ccfc67b7
JH
1427=head1 Array Manipulation Functions
1428
84d4ea48
JH
1429=for apidoc sortsv
1430
1431Sort an array. Here is an example:
1432
4eb872f6 1433 sortsv(AvARRAY(av), av_len(av)+1, Perl_sv_cmp_locale);
84d4ea48 1434
78210658
AD
1435See lib/sort.pm for details about controlling the sorting algorithm.
1436
84d4ea48
JH
1437=cut
1438*/
4eb872f6 1439
84d4ea48
JH
1440void
1441Perl_sortsv(pTHX_ SV **array, size_t nmemb, SVCOMPARE_t cmp)
1442{
6c3fb703
NC
1443 void (*sortsvp)(pTHX_ SV **array, size_t nmemb, SVCOMPARE_t cmp, U32 flags)
1444 = S_mergesortsv;
045ac317 1445 SV *hintsv;
84d4ea48 1446 I32 hints;
4eb872f6 1447
78210658
AD
1448 /* Sun's Compiler (cc: WorkShop Compilers 4.2 30 Oct 1996 C 4.2) used
1449 to miscompile this function under optimization -O. If you get test
1450 errors related to picking the correct sort() function, try recompiling
1451 this file without optimiziation. -- A.D. 4/2002.
1452 */
045ac317 1453 hints = SORTHINTS(hintsv);
78210658
AD
1454 if (hints & HINT_SORT_QUICKSORT) {
1455 sortsvp = S_qsortsv;
1456 }
1457 else {
1458 /* The default as of 5.8.0 is mergesort */
1459 sortsvp = S_mergesortsv;
84d4ea48 1460 }
4eb872f6 1461
6c3fb703
NC
1462 sortsvp(aTHX_ array, nmemb, cmp, 0);
1463}
1464
1465
b7787f18 1466static void
6c3fb703
NC
1467S_sortsv_desc(pTHX_ SV **array, size_t nmemb, SVCOMPARE_t cmp)
1468{
1469 void (*sortsvp)(pTHX_ SV **array, size_t nmemb, SVCOMPARE_t cmp, U32 flags)
1470 = S_mergesortsv;
1471 SV *hintsv;
1472 I32 hints;
1473
1474 /* Sun's Compiler (cc: WorkShop Compilers 4.2 30 Oct 1996 C 4.2) used
1475 to miscompile this function under optimization -O. If you get test
1476 errors related to picking the correct sort() function, try recompiling
1477 this file without optimiziation. -- A.D. 4/2002.
1478 */
1479 hints = SORTHINTS(hintsv);
1480 if (hints & HINT_SORT_QUICKSORT) {
1481 sortsvp = S_qsortsv;
1482 }
1483 else {
1484 /* The default as of 5.8.0 is mergesort */
1485 sortsvp = S_mergesortsv;
1486 }
1487
1488 sortsvp(aTHX_ array, nmemb, cmp, 1);
84d4ea48
JH
1489}
1490
4d562308
SF
1491#define SvNSIOK(sv) ((SvFLAGS(sv) & SVf_NOK) || ((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV)) == SVf_IOK))
1492#define SvSIOK(sv) ((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV)) == SVf_IOK)
1493#define SvNSIV(sv) ( SvNOK(sv) ? SvNVX(sv) : ( SvSIOK(sv) ? SvIVX(sv) : sv_2nv(sv) ) )
1494
84d4ea48
JH
1495PP(pp_sort)
1496{
27da23d5 1497 dVAR; dSP; dMARK; dORIGMARK;
fe1bc4cf
DM
1498 register SV **p1 = ORIGMARK+1, **p2;
1499 register I32 max, i;
1500 AV* av = Nullav;
84d4ea48
JH
1501 HV *stash;
1502 GV *gv;
1503 CV *cv = 0;
1504 I32 gimme = GIMME;
1505 OP* nextop = PL_op->op_next;
1506 I32 overloading = 0;
1507 bool hasargs = FALSE;
1508 I32 is_xsub = 0;
fe1bc4cf 1509 I32 sorting_av = 0;
0723351e 1510 U8 priv = PL_op->op_private;
471178c0 1511 U8 flags = PL_op->op_flags;
6c3fb703
NC
1512 void (*sortsvp)(pTHX_ SV **array, size_t nmemb, SVCOMPARE_t cmp)
1513 = Perl_sortsv;
4d562308 1514 I32 all_SIVs = 1;
84d4ea48
JH
1515
1516 if (gimme != G_ARRAY) {
1517 SP = MARK;
1518 RETPUSHUNDEF;
1519 }
1520
1521 ENTER;
1522 SAVEVPTR(PL_sortcop);
471178c0
NC
1523 if (flags & OPf_STACKED) {
1524 if (flags & OPf_SPECIAL) {
84d4ea48
JH
1525 OP *kid = cLISTOP->op_first->op_sibling; /* pass pushmark */
1526 kid = kUNOP->op_first; /* pass rv2gv */
1527 kid = kUNOP->op_first; /* pass leave */
1528 PL_sortcop = kid->op_next;
1529 stash = CopSTASH(PL_curcop);
1530 }
1531 else {
1532 cv = sv_2cv(*++MARK, &stash, &gv, 0);
1533 if (cv && SvPOK(cv)) {
349d4f2f 1534 const char *proto = SvPV_nolen_const((SV*)cv);
84d4ea48
JH
1535 if (proto && strEQ(proto, "$$")) {
1536 hasargs = TRUE;
1537 }
1538 }
1539 if (!(cv && CvROOT(cv))) {
1540 if (cv && CvXSUB(cv)) {
1541 is_xsub = 1;
1542 }
1543 else if (gv) {
1544 SV *tmpstr = sv_newmortal();
1545 gv_efullname3(tmpstr, gv, Nullch);
35c1215d
NC
1546 DIE(aTHX_ "Undefined sort subroutine \"%"SVf"\" called",
1547 tmpstr);
84d4ea48
JH
1548 }
1549 else {
1550 DIE(aTHX_ "Undefined subroutine in sort");
1551 }
1552 }
1553
1554 if (is_xsub)
1555 PL_sortcop = (OP*)cv;
1556 else {
1557 PL_sortcop = CvSTART(cv);
1558 SAVEVPTR(CvROOT(cv)->op_ppaddr);
1559 CvROOT(cv)->op_ppaddr = PL_ppaddr[OP_NULL];
1560
dd2155a4 1561 PAD_SET_CUR(CvPADLIST(cv), 1);
84d4ea48
JH
1562 }
1563 }
1564 }
1565 else {
1566 PL_sortcop = Nullop;
1567 stash = CopSTASH(PL_curcop);
1568 }
1569
fe1bc4cf
DM
1570 /* optimiser converts "@a = sort @a" to "sort \@a";
1571 * in case of tied @a, pessimise: push (@a) onto stack, then assign
1572 * result back to @a at the end of this function */
0723351e 1573 if (priv & OPpSORT_INPLACE) {
fe1bc4cf
DM
1574 assert( MARK+1 == SP && *SP && SvTYPE(*SP) == SVt_PVAV);
1575 (void)POPMARK; /* remove mark associated with ex-OP_AASSIGN */
1576 av = (AV*)(*SP);
1577 max = AvFILL(av) + 1;
1578 if (SvMAGICAL(av)) {
1579 MEXTEND(SP, max);
1580 p2 = SP;
fe2774ed 1581 for (i=0; i < max; i++) {
fe1bc4cf
DM
1582 SV **svp = av_fetch(av, i, FALSE);
1583 *SP++ = (svp) ? *svp : Nullsv;
1584 }
1585 }
1586 else {
1587 p1 = p2 = AvARRAY(av);
1588 sorting_av = 1;
1589 }
1590 }
1591 else {
1592 p2 = MARK+1;
1593 max = SP - MARK;
1594 }
1595
0723351e 1596 if (priv & OPpSORT_DESCEND) {
6c3fb703
NC
1597 sortsvp = S_sortsv_desc;
1598 }
1599
83a44efe
SF
1600 /* shuffle stack down, removing optional initial cv (p1!=p2), plus
1601 * any nulls; also stringify or converting to integer or number as
1602 * required any args */
fe1bc4cf
DM
1603 for (i=max; i > 0 ; i--) {
1604 if ((*p1 = *p2++)) { /* Weed out nulls. */
1605 SvTEMP_off(*p1);
83a44efe
SF
1606 if (!PL_sortcop) {
1607 if (priv & OPpSORT_NUMERIC) {
1608 if (priv & OPpSORT_INTEGER) {
1609 if (!SvIOK(*p1)) {
1610 if (SvAMAGIC(*p1))
1611 overloading = 1;
1612 else
1613 (void)sv_2iv(*p1);
1614 }
1615 }
1616 else {
4d562308 1617 if (!SvNSIOK(*p1)) {
83a44efe
SF
1618 if (SvAMAGIC(*p1))
1619 overloading = 1;
1620 else
1621 (void)sv_2nv(*p1);
1622 }
4d562308
SF
1623 if (all_SIVs && !SvSIOK(*p1))
1624 all_SIVs = 0;
83a44efe
SF
1625 }
1626 }
1627 else {
1628 if (!SvPOK(*p1)) {
83a44efe
SF
1629 if (SvAMAGIC(*p1))
1630 overloading = 1;
1631 else
83003860
NC
1632 (void)sv_2pv_flags(*p1, 0,
1633 SV_GMAGIC|SV_CONST_RETURN);
83a44efe
SF
1634 }
1635 }
84d4ea48 1636 }
fe1bc4cf 1637 p1++;
84d4ea48 1638 }
fe1bc4cf
DM
1639 else
1640 max--;
84d4ea48 1641 }
fe1bc4cf
DM
1642 if (sorting_av)
1643 AvFILLp(av) = max-1;
1644
1645 if (max > 1) {
471178c0 1646 SV **start;
fe1bc4cf 1647 if (PL_sortcop) {
84d4ea48
JH
1648 PERL_CONTEXT *cx;
1649 SV** newsp;
1650 bool oldcatch = CATCH_GET;
1651
1652 SAVETMPS;
1653 SAVEOP();
1654
1655 CATCH_SET(TRUE);
1656 PUSHSTACKi(PERLSI_SORT);
1657 if (!hasargs && !is_xsub) {
1658 if (PL_sortstash != stash || !PL_firstgv || !PL_secondgv) {
1659 SAVESPTR(PL_firstgv);
1660 SAVESPTR(PL_secondgv);
1661 PL_firstgv = gv_fetchpv("a", TRUE, SVt_PV);
1662 PL_secondgv = gv_fetchpv("b", TRUE, SVt_PV);
1663 PL_sortstash = stash;
1664 }
84d4ea48
JH
1665 SAVESPTR(GvSV(PL_firstgv));
1666 SAVESPTR(GvSV(PL_secondgv));
1667 }
1668
1669 PUSHBLOCK(cx, CXt_NULL, PL_stack_base);
471178c0 1670 if (!(flags & OPf_SPECIAL)) {
84d4ea48
JH
1671 cx->cx_type = CXt_SUB;
1672 cx->blk_gimme = G_SCALAR;
1673 PUSHSUB(cx);
84d4ea48
JH
1674 }
1675 PL_sortcxix = cxstack_ix;
1676
1677 if (hasargs && !is_xsub) {
1678 /* This is mostly copied from pp_entersub */
dd2155a4 1679 AV *av = (AV*)PAD_SVl(0);
84d4ea48 1680
84d4ea48
JH
1681 cx->blk_sub.savearray = GvAV(PL_defgv);
1682 GvAV(PL_defgv) = (AV*)SvREFCNT_inc(av);
dd2155a4 1683 CX_CURPAD_SAVE(cx->blk_sub);
84d4ea48
JH
1684 cx->blk_sub.argarray = av;
1685 }
471178c0
NC
1686
1687 start = p1 - max;
1688 sortsvp(aTHX_ start, max,
1689 is_xsub ? sortcv_xsub : hasargs ? sortcv_stacked : sortcv);
84d4ea48
JH
1690
1691 POPBLOCK(cx,PL_curpm);
1692 PL_stack_sp = newsp;
1693 POPSTACK;
1694 CATCH_SET(oldcatch);
1695 }
fe1bc4cf 1696 else {
84d4ea48 1697 MEXTEND(SP, 20); /* Can't afford stack realloc on signal. */
471178c0
NC
1698 start = sorting_av ? AvARRAY(av) : ORIGMARK+1;
1699 sortsvp(aTHX_ start, max,
0723351e 1700 (priv & OPpSORT_NUMERIC)
4d562308 1701 ? ( ( ( priv & OPpSORT_INTEGER) || all_SIVs)
84d4ea48 1702 ? ( overloading ? amagic_i_ncmp : sv_i_ncmp)
4d562308 1703 : ( overloading ? amagic_ncmp : sv_ncmp ) )
84d4ea48
JH
1704 : ( IN_LOCALE_RUNTIME
1705 ? ( overloading
1706 ? amagic_cmp_locale
1707 : sv_cmp_locale_static)
1708 : ( overloading ? amagic_cmp : sv_cmp_static)));
471178c0 1709 }
0723351e 1710 if (priv & OPpSORT_REVERSE) {
471178c0
NC
1711 SV **q = start+max-1;
1712 while (start < q) {
1713 SV *tmp = *start;
1714 *start++ = *q;
1715 *q-- = tmp;
84d4ea48
JH
1716 }
1717 }
1718 }
fe1bc4cf
DM
1719 if (av && !sorting_av) {
1720 /* simulate pp_aassign of tied AV */
1721 SV *sv;
1722 SV** base, **didstore;
1723 for (base = ORIGMARK+1, i=0; i < max; i++) {
f2b990bf 1724 sv = newSVsv(base[i]);
fe1bc4cf
DM
1725 base[i] = sv;
1726 }
1727 av_clear(av);
1728 av_extend(av, max);
1729 for (i=0; i < max; i++) {
1730 sv = base[i];
1731 didstore = av_store(av, i, sv);
1732 if (SvSMAGICAL(sv))
1733 mg_set(sv);
1734 if (!didstore)
1735 sv_2mortal(sv);
1736 }
1737 }
84d4ea48 1738 LEAVE;
fe1bc4cf 1739 PL_stack_sp = ORIGMARK + (sorting_av ? 0 : max);
84d4ea48
JH
1740 return nextop;
1741}
1742
1743static I32
1744sortcv(pTHX_ SV *a, SV *b)
1745{
27da23d5 1746 dVAR;
84d4ea48
JH
1747 I32 oldsaveix = PL_savestack_ix;
1748 I32 oldscopeix = PL_scopestack_ix;
1749 I32 result;
1750 GvSV(PL_firstgv) = a;
1751 GvSV(PL_secondgv) = b;
1752 PL_stack_sp = PL_stack_base;
1753 PL_op = PL_sortcop;
1754 CALLRUNOPS(aTHX);
1755 if (PL_stack_sp != PL_stack_base + 1)
1756 Perl_croak(aTHX_ "Sort subroutine didn't return single value");
1757 if (!SvNIOKp(*PL_stack_sp))
1758 Perl_croak(aTHX_ "Sort subroutine didn't return a numeric value");
1759 result = SvIV(*PL_stack_sp);
1760 while (PL_scopestack_ix > oldscopeix) {
1761 LEAVE;
1762 }
1763 leave_scope(oldsaveix);
1764 return result;
1765}
1766
1767static I32
1768sortcv_stacked(pTHX_ SV *a, SV *b)
1769{
27da23d5 1770 dVAR;
84d4ea48
JH
1771 I32 oldsaveix = PL_savestack_ix;
1772 I32 oldscopeix = PL_scopestack_ix;
1773 I32 result;
1774 AV *av;
1775
84d4ea48 1776 av = GvAV(PL_defgv);
84d4ea48
JH
1777
1778 if (AvMAX(av) < 1) {
1779 SV** ary = AvALLOC(av);
1780 if (AvARRAY(av) != ary) {
1781 AvMAX(av) += AvARRAY(av) - AvALLOC(av);
f880fe2f 1782 SvPV_set(av, (char*)ary);
84d4ea48
JH
1783 }
1784 if (AvMAX(av) < 1) {
1785 AvMAX(av) = 1;
1786 Renew(ary,2,SV*);
f880fe2f 1787 SvPV_set(av, (char*)ary);
84d4ea48
JH
1788 }
1789 }
1790 AvFILLp(av) = 1;
1791
1792 AvARRAY(av)[0] = a;
1793 AvARRAY(av)[1] = b;
1794 PL_stack_sp = PL_stack_base;
1795 PL_op = PL_sortcop;
1796 CALLRUNOPS(aTHX);
1797 if (PL_stack_sp != PL_stack_base + 1)
1798 Perl_croak(aTHX_ "Sort subroutine didn't return single value");
1799 if (!SvNIOKp(*PL_stack_sp))
1800 Perl_croak(aTHX_ "Sort subroutine didn't return a numeric value");
1801 result = SvIV(*PL_stack_sp);
1802 while (PL_scopestack_ix > oldscopeix) {
1803 LEAVE;
1804 }
1805 leave_scope(oldsaveix);
1806 return result;
1807}
1808
1809static I32
1810sortcv_xsub(pTHX_ SV *a, SV *b)
1811{
27da23d5 1812 dVAR; dSP;
84d4ea48
JH
1813 I32 oldsaveix = PL_savestack_ix;
1814 I32 oldscopeix = PL_scopestack_ix;
1815 I32 result;
1816 CV *cv=(CV*)PL_sortcop;
1817
1818 SP = PL_stack_base;
1819 PUSHMARK(SP);
1820 EXTEND(SP, 2);
1821 *++SP = a;
1822 *++SP = b;
1823 PUTBACK;
1824 (void)(*CvXSUB(cv))(aTHX_ cv);
1825 if (PL_stack_sp != PL_stack_base + 1)
1826 Perl_croak(aTHX_ "Sort subroutine didn't return single value");
1827 if (!SvNIOKp(*PL_stack_sp))
1828 Perl_croak(aTHX_ "Sort subroutine didn't return a numeric value");
1829 result = SvIV(*PL_stack_sp);
1830 while (PL_scopestack_ix > oldscopeix) {
1831 LEAVE;
1832 }
1833 leave_scope(oldsaveix);
1834 return result;
1835}
1836
1837
1838static I32
1839sv_ncmp(pTHX_ SV *a, SV *b)
1840{
4d562308
SF
1841 NV nv1 = SvNSIV(a);
1842 NV nv2 = SvNSIV(b);
84d4ea48
JH
1843 return nv1 < nv2 ? -1 : nv1 > nv2 ? 1 : 0;
1844}
1845
1846static I32
1847sv_i_ncmp(pTHX_ SV *a, SV *b)
1848{
1849 IV iv1 = SvIV(a);
1850 IV iv2 = SvIV(b);
1851 return iv1 < iv2 ? -1 : iv1 > iv2 ? 1 : 0;
1852}
1853#define tryCALL_AMAGICbin(left,right,meth,svp) STMT_START { \
1854 *svp = Nullsv; \
1855 if (PL_amagic_generation) { \
1856 if (SvAMAGIC(left)||SvAMAGIC(right))\
1857 *svp = amagic_call(left, \
1858 right, \
1859 CAT2(meth,_amg), \
1860 0); \
1861 } \
1862 } STMT_END
1863
1864static I32
1865amagic_ncmp(pTHX_ register SV *a, register SV *b)
1866{
1867 SV *tmpsv;
1868 tryCALL_AMAGICbin(a,b,ncmp,&tmpsv);
1869 if (tmpsv) {
1870 NV d;
4eb872f6 1871
84d4ea48
JH
1872 if (SvIOK(tmpsv)) {
1873 I32 i = SvIVX(tmpsv);
1874 if (i > 0)
1875 return 1;
1876 return i? -1 : 0;
1877 }
1878 d = SvNV(tmpsv);
1879 if (d > 0)
1880 return 1;
1881 return d? -1 : 0;
1882 }
1883 return sv_ncmp(aTHX_ a, b);
1884}
1885
1886static I32
1887amagic_i_ncmp(pTHX_ register SV *a, register SV *b)
1888{
1889 SV *tmpsv;
1890 tryCALL_AMAGICbin(a,b,ncmp,&tmpsv);
1891 if (tmpsv) {
1892 NV d;
4eb872f6 1893
84d4ea48
JH
1894 if (SvIOK(tmpsv)) {
1895 I32 i = SvIVX(tmpsv);
1896 if (i > 0)
1897 return 1;
1898 return i? -1 : 0;
1899 }
1900 d = SvNV(tmpsv);
1901 if (d > 0)
1902 return 1;
1903 return d? -1 : 0;
1904 }
1905 return sv_i_ncmp(aTHX_ a, b);
1906}
1907
1908static I32
1909amagic_cmp(pTHX_ register SV *str1, register SV *str2)
1910{
1911 SV *tmpsv;
1912 tryCALL_AMAGICbin(str1,str2,scmp,&tmpsv);
1913 if (tmpsv) {
1914 NV d;
4eb872f6 1915
84d4ea48
JH
1916 if (SvIOK(tmpsv)) {
1917 I32 i = SvIVX(tmpsv);
1918 if (i > 0)
1919 return 1;
1920 return i? -1 : 0;
1921 }
1922 d = SvNV(tmpsv);
1923 if (d > 0)
1924 return 1;
1925 return d? -1 : 0;
1926 }
1927 return sv_cmp(str1, str2);
1928}
1929
1930static I32
1931amagic_cmp_locale(pTHX_ register SV *str1, register SV *str2)
1932{
1933 SV *tmpsv;
1934 tryCALL_AMAGICbin(str1,str2,scmp,&tmpsv);
1935 if (tmpsv) {
1936 NV d;
4eb872f6 1937
84d4ea48
JH
1938 if (SvIOK(tmpsv)) {
1939 I32 i = SvIVX(tmpsv);
1940 if (i > 0)
1941 return 1;
1942 return i? -1 : 0;
1943 }
1944 d = SvNV(tmpsv);
1945 if (d > 0)
1946 return 1;
1947 return d? -1 : 0;
1948 }
1949 return sv_cmp_locale(str1, str2);
1950}
241d1a3b
NC
1951
1952/*
1953 * Local variables:
1954 * c-indentation-style: bsd
1955 * c-basic-offset: 4
1956 * indent-tabs-mode: t
1957 * End:
1958 *
37442d52
RGS
1959 * ex: set ts=8 sts=4 sw=4 noet:
1960 */