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84d4ea48 JH |
1 | /* pp_sort.c |
2 | * | |
1129b882 NC |
3 | * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, |
4 | * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others | |
84d4ea48 JH |
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 | /* | |
4ac71550 TC |
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 | * [p.931 of _The Lord of the Rings_, VI/ii: "The Land of Shadow"] | |
84d4ea48 JH |
16 | */ |
17 | ||
166f8a29 DM |
18 | /* This file contains pp ("push/pop") functions that |
19 | * execute the opcodes that make up a perl program. A typical pp function | |
20 | * expects to find its arguments on the stack, and usually pushes its | |
21 | * results onto the stack, hence the 'pp' terminology. Each OP structure | |
22 | * contains a pointer to the relevant pp_foo() function. | |
23 | * | |
24 | * This particular file just contains pp_sort(), which is complex | |
25 | * enough to merit its own file! See the other pp*.c files for the rest of | |
26 | * the pp_ functions. | |
27 | */ | |
28 | ||
84d4ea48 JH |
29 | #include "EXTERN.h" |
30 | #define PERL_IN_PP_SORT_C | |
31 | #include "perl.h" | |
32 | ||
42165d27 VK |
33 | #if defined(UNDER_CE) |
34 | /* looks like 'small' is reserved word for WINCE (or somesuch)*/ | |
35 | #define small xsmall | |
36 | #endif | |
37 | ||
84d4ea48 JH |
38 | #define sv_cmp_static Perl_sv_cmp |
39 | #define sv_cmp_locale_static Perl_sv_cmp_locale | |
40 | ||
c53fc8a6 JH |
41 | #ifndef SMALLSORT |
42 | #define SMALLSORT (200) | |
43 | #endif | |
44 | ||
7b9ef140 RH |
45 | /* Flags for qsortsv and mergesortsv */ |
46 | #define SORTf_DESC 1 | |
47 | #define SORTf_STABLE 2 | |
48 | #define SORTf_QSORT 4 | |
49 | ||
84d4ea48 JH |
50 | /* |
51 | * The mergesort implementation is by Peter M. Mcilroy <pmcilroy@lucent.com>. | |
52 | * | |
53 | * The original code was written in conjunction with BSD Computer Software | |
54 | * Research Group at University of California, Berkeley. | |
55 | * | |
56 | * See also: "Optimistic Merge Sort" (SODA '92) | |
57 | * | |
58 | * The integration to Perl is by John P. Linderman <jpl@research.att.com>. | |
59 | * | |
60 | * The code can be distributed under the same terms as Perl itself. | |
61 | * | |
62 | */ | |
63 | ||
84d4ea48 JH |
64 | |
65 | typedef char * aptr; /* pointer for arithmetic on sizes */ | |
66 | typedef SV * gptr; /* pointers in our lists */ | |
67 | ||
68 | /* Binary merge internal sort, with a few special mods | |
69 | ** for the special perl environment it now finds itself in. | |
70 | ** | |
71 | ** Things that were once options have been hotwired | |
72 | ** to values suitable for this use. In particular, we'll always | |
73 | ** initialize looking for natural runs, we'll always produce stable | |
74 | ** output, and we'll always do Peter McIlroy's binary merge. | |
75 | */ | |
76 | ||
77 | /* Pointer types for arithmetic and storage and convenience casts */ | |
78 | ||
79 | #define APTR(P) ((aptr)(P)) | |
80 | #define GPTP(P) ((gptr *)(P)) | |
81 | #define GPPP(P) ((gptr **)(P)) | |
82 | ||
83 | ||
84 | /* byte offset from pointer P to (larger) pointer Q */ | |
85 | #define BYTEOFF(P, Q) (APTR(Q) - APTR(P)) | |
86 | ||
87 | #define PSIZE sizeof(gptr) | |
88 | ||
89 | /* If PSIZE is power of 2, make PSHIFT that power, if that helps */ | |
90 | ||
91 | #ifdef PSHIFT | |
92 | #define PNELEM(P, Q) (BYTEOFF(P,Q) >> (PSHIFT)) | |
93 | #define PNBYTE(N) ((N) << (PSHIFT)) | |
94 | #define PINDEX(P, N) (GPTP(APTR(P) + PNBYTE(N))) | |
95 | #else | |
96 | /* Leave optimization to compiler */ | |
97 | #define PNELEM(P, Q) (GPTP(Q) - GPTP(P)) | |
98 | #define PNBYTE(N) ((N) * (PSIZE)) | |
99 | #define PINDEX(P, N) (GPTP(P) + (N)) | |
100 | #endif | |
101 | ||
102 | /* Pointer into other corresponding to pointer into this */ | |
103 | #define POTHER(P, THIS, OTHER) GPTP(APTR(OTHER) + BYTEOFF(THIS,P)) | |
104 | ||
105 | #define FROMTOUPTO(src, dst, lim) do *dst++ = *src++; while(src<lim) | |
106 | ||
107 | ||
108 | /* Runs are identified by a pointer in the auxilliary list. | |
109 | ** The pointer is at the start of the list, | |
110 | ** and it points to the start of the next list. | |
111 | ** NEXT is used as an lvalue, too. | |
112 | */ | |
113 | ||
114 | #define NEXT(P) (*GPPP(P)) | |
115 | ||
116 | ||
117 | /* PTHRESH is the minimum number of pairs with the same sense to justify | |
118 | ** checking for a run and extending it. Note that PTHRESH counts PAIRS, | |
119 | ** not just elements, so PTHRESH == 8 means a run of 16. | |
120 | */ | |
121 | ||
122 | #define PTHRESH (8) | |
123 | ||
124 | /* RTHRESH is the number of elements in a run that must compare low | |
125 | ** to the low element from the opposing run before we justify | |
126 | ** doing a binary rampup instead of single stepping. | |
127 | ** In random input, N in a row low should only happen with | |
128 | ** probability 2^(1-N), so we can risk that we are dealing | |
129 | ** with orderly input without paying much when we aren't. | |
130 | */ | |
131 | ||
132 | #define RTHRESH (6) | |
133 | ||
134 | ||
135 | /* | |
136 | ** Overview of algorithm and variables. | |
137 | ** The array of elements at list1 will be organized into runs of length 2, | |
138 | ** or runs of length >= 2 * PTHRESH. We only try to form long runs when | |
139 | ** PTHRESH adjacent pairs compare in the same way, suggesting overall order. | |
140 | ** | |
141 | ** Unless otherwise specified, pair pointers address the first of two elements. | |
142 | ** | |
a0288114 AL |
143 | ** b and b+1 are a pair that compare with sense "sense". |
144 | ** b is the "bottom" of adjacent pairs that might form a longer run. | |
84d4ea48 JH |
145 | ** |
146 | ** p2 parallels b in the list2 array, where runs are defined by | |
147 | ** a pointer chain. | |
148 | ** | |
a0288114 | 149 | ** t represents the "top" of the adjacent pairs that might extend |
84d4ea48 JH |
150 | ** the run beginning at b. Usually, t addresses a pair |
151 | ** that compares with opposite sense from (b,b+1). | |
152 | ** However, it may also address a singleton element at the end of list1, | |
a0288114 | 153 | ** or it may be equal to "last", the first element beyond list1. |
84d4ea48 JH |
154 | ** |
155 | ** r addresses the Nth pair following b. If this would be beyond t, | |
156 | ** we back it off to t. Only when r is less than t do we consider the | |
157 | ** run long enough to consider checking. | |
158 | ** | |
159 | ** q addresses a pair such that the pairs at b through q already form a run. | |
160 | ** Often, q will equal b, indicating we only are sure of the pair itself. | |
161 | ** However, a search on the previous cycle may have revealed a longer run, | |
162 | ** so q may be greater than b. | |
163 | ** | |
164 | ** p is used to work back from a candidate r, trying to reach q, | |
165 | ** which would mean b through r would be a run. If we discover such a run, | |
166 | ** we start q at r and try to push it further towards t. | |
167 | ** If b through r is NOT a run, we detect the wrong order at (p-1,p). | |
168 | ** In any event, after the check (if any), we have two main cases. | |
169 | ** | |
170 | ** 1) Short run. b <= q < p <= r <= t. | |
171 | ** b through q is a run (perhaps trivial) | |
172 | ** q through p are uninteresting pairs | |
173 | ** p through r is a run | |
174 | ** | |
175 | ** 2) Long run. b < r <= q < t. | |
176 | ** b through q is a run (of length >= 2 * PTHRESH) | |
177 | ** | |
178 | ** Note that degenerate cases are not only possible, but likely. | |
179 | ** For example, if the pair following b compares with opposite sense, | |
180 | ** then b == q < p == r == t. | |
181 | */ | |
182 | ||
183 | ||
957d8989 | 184 | static IV |
d4c19fe8 | 185 | dynprep(pTHX_ gptr *list1, gptr *list2, size_t nmemb, const SVCOMPARE_t cmp) |
84d4ea48 | 186 | { |
957d8989 | 187 | I32 sense; |
84d4ea48 | 188 | register gptr *b, *p, *q, *t, *p2; |
d4c19fe8 | 189 | register gptr *last, *r; |
957d8989 | 190 | IV runs = 0; |
84d4ea48 JH |
191 | |
192 | b = list1; | |
193 | last = PINDEX(b, nmemb); | |
194 | sense = (cmp(aTHX_ *b, *(b+1)) > 0); | |
195 | for (p2 = list2; b < last; ) { | |
196 | /* We just started, or just reversed sense. | |
197 | ** Set t at end of pairs with the prevailing sense. | |
198 | */ | |
199 | for (p = b+2, t = p; ++p < last; t = ++p) { | |
200 | if ((cmp(aTHX_ *t, *p) > 0) != sense) break; | |
201 | } | |
202 | q = b; | |
203 | /* Having laid out the playing field, look for long runs */ | |
204 | do { | |
205 | p = r = b + (2 * PTHRESH); | |
206 | if (r >= t) p = r = t; /* too short to care about */ | |
207 | else { | |
208 | while (((cmp(aTHX_ *(p-1), *p) > 0) == sense) && | |
47127b64 | 209 | ((p -= 2) > q)) {} |
84d4ea48 JH |
210 | if (p <= q) { |
211 | /* b through r is a (long) run. | |
212 | ** Extend it as far as possible. | |
213 | */ | |
214 | p = q = r; | |
215 | while (((p += 2) < t) && | |
216 | ((cmp(aTHX_ *(p-1), *p) > 0) == sense)) q = p; | |
217 | r = p = q + 2; /* no simple pairs, no after-run */ | |
218 | } | |
219 | } | |
220 | if (q > b) { /* run of greater than 2 at b */ | |
d4c19fe8 AL |
221 | gptr *savep = p; |
222 | ||
84d4ea48 JH |
223 | p = q += 2; |
224 | /* pick up singleton, if possible */ | |
225 | if ((p == t) && | |
226 | ((t + 1) == last) && | |
227 | ((cmp(aTHX_ *(p-1), *p) > 0) == sense)) | |
228 | savep = r = p = q = last; | |
957d8989 | 229 | p2 = NEXT(p2) = p2 + (p - b); ++runs; |
d4c19fe8 AL |
230 | if (sense) |
231 | while (b < --p) { | |
232 | const gptr c = *b; | |
233 | *b++ = *p; | |
234 | *p = c; | |
235 | } | |
84d4ea48 JH |
236 | p = savep; |
237 | } | |
238 | while (q < p) { /* simple pairs */ | |
957d8989 | 239 | p2 = NEXT(p2) = p2 + 2; ++runs; |
84d4ea48 | 240 | if (sense) { |
d4c19fe8 | 241 | const gptr c = *q++; |
84d4ea48 JH |
242 | *(q-1) = *q; |
243 | *q++ = c; | |
244 | } else q += 2; | |
245 | } | |
246 | if (((b = p) == t) && ((t+1) == last)) { | |
957d8989 | 247 | NEXT(p2) = p2 + 1; ++runs; |
84d4ea48 JH |
248 | b++; |
249 | } | |
250 | q = r; | |
251 | } while (b < t); | |
252 | sense = !sense; | |
253 | } | |
957d8989 | 254 | return runs; |
84d4ea48 JH |
255 | } |
256 | ||
257 | ||
3fe0b9a9 | 258 | /* The original merge sort, in use since 5.7, was as fast as, or faster than, |
957d8989 | 259 | * qsort on many platforms, but slower than qsort, conspicuously so, |
3fe0b9a9 | 260 | * on others. The most likely explanation was platform-specific |
957d8989 JL |
261 | * differences in cache sizes and relative speeds. |
262 | * | |
263 | * The quicksort divide-and-conquer algorithm guarantees that, as the | |
264 | * problem is subdivided into smaller and smaller parts, the parts | |
265 | * fit into smaller (and faster) caches. So it doesn't matter how | |
266 | * many levels of cache exist, quicksort will "find" them, and, | |
e62b3022 | 267 | * as long as smaller is faster, take advantage of them. |
957d8989 | 268 | * |
3fe0b9a9 | 269 | * By contrast, consider how the original mergesort algorithm worked. |
957d8989 JL |
270 | * Suppose we have five runs (each typically of length 2 after dynprep). |
271 | * | |
272 | * pass base aux | |
273 | * 0 1 2 3 4 5 | |
274 | * 1 12 34 5 | |
275 | * 2 1234 5 | |
276 | * 3 12345 | |
277 | * 4 12345 | |
278 | * | |
279 | * Adjacent pairs are merged in "grand sweeps" through the input. | |
280 | * This means, on pass 1, the records in runs 1 and 2 aren't revisited until | |
281 | * runs 3 and 4 are merged and the runs from run 5 have been copied. | |
282 | * The only cache that matters is one large enough to hold *all* the input. | |
283 | * On some platforms, this may be many times slower than smaller caches. | |
284 | * | |
285 | * The following pseudo-code uses the same basic merge algorithm, | |
286 | * but in a divide-and-conquer way. | |
287 | * | |
288 | * # merge $runs runs at offset $offset of list $list1 into $list2. | |
289 | * # all unmerged runs ($runs == 1) originate in list $base. | |
290 | * sub mgsort2 { | |
291 | * my ($offset, $runs, $base, $list1, $list2) = @_; | |
292 | * | |
293 | * if ($runs == 1) { | |
294 | * if ($list1 is $base) copy run to $list2 | |
295 | * return offset of end of list (or copy) | |
296 | * } else { | |
297 | * $off2 = mgsort2($offset, $runs-($runs/2), $base, $list2, $list1) | |
298 | * mgsort2($off2, $runs/2, $base, $list2, $list1) | |
299 | * merge the adjacent runs at $offset of $list1 into $list2 | |
300 | * return the offset of the end of the merged runs | |
301 | * } | |
302 | * } | |
303 | * mgsort2(0, $runs, $base, $aux, $base); | |
304 | * | |
305 | * For our 5 runs, the tree of calls looks like | |
306 | * | |
307 | * 5 | |
308 | * 3 2 | |
309 | * 2 1 1 1 | |
310 | * 1 1 | |
311 | * | |
312 | * 1 2 3 4 5 | |
313 | * | |
314 | * and the corresponding activity looks like | |
315 | * | |
316 | * copy runs 1 and 2 from base to aux | |
317 | * merge runs 1 and 2 from aux to base | |
318 | * (run 3 is where it belongs, no copy needed) | |
319 | * merge runs 12 and 3 from base to aux | |
320 | * (runs 4 and 5 are where they belong, no copy needed) | |
321 | * merge runs 4 and 5 from base to aux | |
322 | * merge runs 123 and 45 from aux to base | |
323 | * | |
324 | * Note that we merge runs 1 and 2 immediately after copying them, | |
325 | * while they are still likely to be in fast cache. Similarly, | |
326 | * run 3 is merged with run 12 while it still may be lingering in cache. | |
327 | * This implementation should therefore enjoy much of the cache-friendly | |
328 | * behavior that quicksort does. In addition, it does less copying | |
329 | * than the original mergesort implementation (only runs 1 and 2 are copied) | |
330 | * and the "balancing" of merges is better (merged runs comprise more nearly | |
331 | * equal numbers of original runs). | |
332 | * | |
333 | * The actual cache-friendly implementation will use a pseudo-stack | |
334 | * to avoid recursion, and will unroll processing of runs of length 2, | |
335 | * but it is otherwise similar to the recursive implementation. | |
957d8989 JL |
336 | */ |
337 | ||
338 | typedef struct { | |
339 | IV offset; /* offset of 1st of 2 runs at this level */ | |
340 | IV runs; /* how many runs must be combined into 1 */ | |
341 | } off_runs; /* pseudo-stack element */ | |
342 | ||
6c3fb703 NC |
343 | |
344 | static I32 | |
31e9e0a3 | 345 | cmp_desc(pTHX_ gptr const a, gptr const b) |
6c3fb703 | 346 | { |
97aff369 | 347 | dVAR; |
6c3fb703 NC |
348 | return -PL_sort_RealCmp(aTHX_ a, b); |
349 | } | |
350 | ||
957d8989 | 351 | STATIC void |
6c3fb703 | 352 | S_mergesortsv(pTHX_ gptr *base, size_t nmemb, SVCOMPARE_t cmp, U32 flags) |
957d8989 | 353 | { |
97aff369 | 354 | dVAR; |
551405c4 | 355 | IV i, run, offset; |
957d8989 | 356 | I32 sense, level; |
551405c4 | 357 | register gptr *f1, *f2, *t, *b, *p; |
957d8989 | 358 | int iwhich; |
551405c4 | 359 | gptr *aux; |
957d8989 JL |
360 | gptr *p1; |
361 | gptr small[SMALLSORT]; | |
362 | gptr *which[3]; | |
363 | off_runs stack[60], *stackp; | |
d4c19fe8 | 364 | SVCOMPARE_t savecmp = NULL; |
957d8989 JL |
365 | |
366 | if (nmemb <= 1) return; /* sorted trivially */ | |
6c3fb703 | 367 | |
f4f44d65 | 368 | if ((flags & SORTf_DESC) != 0) { |
6c3fb703 NC |
369 | savecmp = PL_sort_RealCmp; /* Save current comparison routine, if any */ |
370 | PL_sort_RealCmp = cmp; /* Put comparison routine where cmp_desc can find it */ | |
371 | cmp = cmp_desc; | |
372 | } | |
373 | ||
957d8989 | 374 | if (nmemb <= SMALLSORT) aux = small; /* use stack for aux array */ |
a02a5408 | 375 | else { Newx(aux,nmemb,gptr); } /* allocate auxilliary array */ |
957d8989 JL |
376 | level = 0; |
377 | stackp = stack; | |
378 | stackp->runs = dynprep(aTHX_ base, aux, nmemb, cmp); | |
379 | stackp->offset = offset = 0; | |
380 | which[0] = which[2] = base; | |
381 | which[1] = aux; | |
382 | for (;;) { | |
383 | /* On levels where both runs have be constructed (stackp->runs == 0), | |
384 | * merge them, and note the offset of their end, in case the offset | |
385 | * is needed at the next level up. Hop up a level, and, | |
386 | * as long as stackp->runs is 0, keep merging. | |
387 | */ | |
551405c4 AL |
388 | IV runs = stackp->runs; |
389 | if (runs == 0) { | |
390 | gptr *list1, *list2; | |
957d8989 JL |
391 | iwhich = level & 1; |
392 | list1 = which[iwhich]; /* area where runs are now */ | |
393 | list2 = which[++iwhich]; /* area for merged runs */ | |
394 | do { | |
551405c4 | 395 | register gptr *l1, *l2, *tp2; |
957d8989 JL |
396 | offset = stackp->offset; |
397 | f1 = p1 = list1 + offset; /* start of first run */ | |
398 | p = tp2 = list2 + offset; /* where merged run will go */ | |
399 | t = NEXT(p); /* where first run ends */ | |
400 | f2 = l1 = POTHER(t, list2, list1); /* ... on the other side */ | |
401 | t = NEXT(t); /* where second runs ends */ | |
402 | l2 = POTHER(t, list2, list1); /* ... on the other side */ | |
403 | offset = PNELEM(list2, t); | |
404 | while (f1 < l1 && f2 < l2) { | |
405 | /* If head 1 is larger than head 2, find ALL the elements | |
406 | ** in list 2 strictly less than head1, write them all, | |
407 | ** then head 1. Then compare the new heads, and repeat, | |
408 | ** until one or both lists are exhausted. | |
409 | ** | |
410 | ** In all comparisons (after establishing | |
411 | ** which head to merge) the item to merge | |
412 | ** (at pointer q) is the first operand of | |
413 | ** the comparison. When we want to know | |
a0288114 | 414 | ** if "q is strictly less than the other", |
957d8989 JL |
415 | ** we can't just do |
416 | ** cmp(q, other) < 0 | |
417 | ** because stability demands that we treat equality | |
418 | ** as high when q comes from l2, and as low when | |
419 | ** q was from l1. So we ask the question by doing | |
420 | ** cmp(q, other) <= sense | |
421 | ** and make sense == 0 when equality should look low, | |
422 | ** and -1 when equality should look high. | |
423 | */ | |
424 | ||
551405c4 | 425 | register gptr *q; |
957d8989 JL |
426 | if (cmp(aTHX_ *f1, *f2) <= 0) { |
427 | q = f2; b = f1; t = l1; | |
428 | sense = -1; | |
429 | } else { | |
430 | q = f1; b = f2; t = l2; | |
431 | sense = 0; | |
432 | } | |
433 | ||
434 | ||
435 | /* ramp up | |
436 | ** | |
437 | ** Leave t at something strictly | |
438 | ** greater than q (or at the end of the list), | |
439 | ** and b at something strictly less than q. | |
440 | */ | |
441 | for (i = 1, run = 0 ;;) { | |
442 | if ((p = PINDEX(b, i)) >= t) { | |
443 | /* off the end */ | |
444 | if (((p = PINDEX(t, -1)) > b) && | |
445 | (cmp(aTHX_ *q, *p) <= sense)) | |
446 | t = p; | |
447 | else b = p; | |
448 | break; | |
449 | } else if (cmp(aTHX_ *q, *p) <= sense) { | |
450 | t = p; | |
451 | break; | |
452 | } else b = p; | |
453 | if (++run >= RTHRESH) i += i; | |
454 | } | |
455 | ||
456 | ||
457 | /* q is known to follow b and must be inserted before t. | |
458 | ** Increment b, so the range of possibilities is [b,t). | |
459 | ** Round binary split down, to favor early appearance. | |
460 | ** Adjust b and t until q belongs just before t. | |
461 | */ | |
462 | ||
463 | b++; | |
464 | while (b < t) { | |
465 | p = PINDEX(b, (PNELEM(b, t) - 1) / 2); | |
466 | if (cmp(aTHX_ *q, *p) <= sense) { | |
467 | t = p; | |
468 | } else b = p + 1; | |
469 | } | |
470 | ||
471 | ||
472 | /* Copy all the strictly low elements */ | |
473 | ||
474 | if (q == f1) { | |
475 | FROMTOUPTO(f2, tp2, t); | |
476 | *tp2++ = *f1++; | |
477 | } else { | |
478 | FROMTOUPTO(f1, tp2, t); | |
479 | *tp2++ = *f2++; | |
480 | } | |
481 | } | |
482 | ||
483 | ||
484 | /* Run out remaining list */ | |
485 | if (f1 == l1) { | |
486 | if (f2 < l2) FROMTOUPTO(f2, tp2, l2); | |
487 | } else FROMTOUPTO(f1, tp2, l1); | |
488 | p1 = NEXT(p1) = POTHER(tp2, list2, list1); | |
489 | ||
490 | if (--level == 0) goto done; | |
491 | --stackp; | |
492 | t = list1; list1 = list2; list2 = t; /* swap lists */ | |
493 | } while ((runs = stackp->runs) == 0); | |
494 | } | |
495 | ||
496 | ||
497 | stackp->runs = 0; /* current run will finish level */ | |
498 | /* While there are more than 2 runs remaining, | |
499 | * turn them into exactly 2 runs (at the "other" level), | |
500 | * each made up of approximately half the runs. | |
501 | * Stack the second half for later processing, | |
502 | * and set about producing the first half now. | |
503 | */ | |
504 | while (runs > 2) { | |
505 | ++level; | |
506 | ++stackp; | |
507 | stackp->offset = offset; | |
508 | runs -= stackp->runs = runs / 2; | |
509 | } | |
510 | /* We must construct a single run from 1 or 2 runs. | |
511 | * All the original runs are in which[0] == base. | |
512 | * The run we construct must end up in which[level&1]. | |
513 | */ | |
514 | iwhich = level & 1; | |
515 | if (runs == 1) { | |
516 | /* Constructing a single run from a single run. | |
517 | * If it's where it belongs already, there's nothing to do. | |
518 | * Otherwise, copy it to where it belongs. | |
519 | * A run of 1 is either a singleton at level 0, | |
520 | * or the second half of a split 3. In neither event | |
521 | * is it necessary to set offset. It will be set by the merge | |
522 | * that immediately follows. | |
523 | */ | |
524 | if (iwhich) { /* Belongs in aux, currently in base */ | |
525 | f1 = b = PINDEX(base, offset); /* where list starts */ | |
526 | f2 = PINDEX(aux, offset); /* where list goes */ | |
527 | t = NEXT(f2); /* where list will end */ | |
528 | offset = PNELEM(aux, t); /* offset thereof */ | |
529 | t = PINDEX(base, offset); /* where it currently ends */ | |
530 | FROMTOUPTO(f1, f2, t); /* copy */ | |
531 | NEXT(b) = t; /* set up parallel pointer */ | |
532 | } else if (level == 0) goto done; /* single run at level 0 */ | |
533 | } else { | |
534 | /* Constructing a single run from two runs. | |
535 | * The merge code at the top will do that. | |
536 | * We need only make sure the two runs are in the "other" array, | |
537 | * so they'll end up in the correct array after the merge. | |
538 | */ | |
539 | ++level; | |
540 | ++stackp; | |
541 | stackp->offset = offset; | |
542 | stackp->runs = 0; /* take care of both runs, trigger merge */ | |
543 | if (!iwhich) { /* Merged runs belong in aux, copy 1st */ | |
544 | f1 = b = PINDEX(base, offset); /* where first run starts */ | |
545 | f2 = PINDEX(aux, offset); /* where it will be copied */ | |
546 | t = NEXT(f2); /* where first run will end */ | |
547 | offset = PNELEM(aux, t); /* offset thereof */ | |
548 | p = PINDEX(base, offset); /* end of first run */ | |
549 | t = NEXT(t); /* where second run will end */ | |
550 | t = PINDEX(base, PNELEM(aux, t)); /* where it now ends */ | |
551 | FROMTOUPTO(f1, f2, t); /* copy both runs */ | |
552 | NEXT(b) = p; /* paralled pointer for 1st */ | |
553 | NEXT(p) = t; /* ... and for second */ | |
554 | } | |
555 | } | |
556 | } | |
557 | done: | |
558 | if (aux != small) Safefree(aux); /* free iff allocated */ | |
6c3fb703 NC |
559 | if (flags) { |
560 | PL_sort_RealCmp = savecmp; /* Restore current comparison routine, if any */ | |
561 | } | |
957d8989 JL |
562 | return; |
563 | } | |
564 | ||
84d4ea48 JH |
565 | /* |
566 | * The quicksort implementation was derived from source code contributed | |
567 | * by Tom Horsley. | |
568 | * | |
569 | * NOTE: this code was derived from Tom Horsley's qsort replacement | |
570 | * and should not be confused with the original code. | |
571 | */ | |
572 | ||
573 | /* Copyright (C) Tom Horsley, 1997. All rights reserved. | |
574 | ||
575 | Permission granted to distribute under the same terms as perl which are | |
576 | (briefly): | |
577 | ||
578 | This program is free software; you can redistribute it and/or modify | |
579 | it under the terms of either: | |
580 | ||
581 | a) the GNU General Public License as published by the Free | |
582 | Software Foundation; either version 1, or (at your option) any | |
583 | later version, or | |
584 | ||
585 | b) the "Artistic License" which comes with this Kit. | |
586 | ||
587 | Details on the perl license can be found in the perl source code which | |
588 | may be located via the www.perl.com web page. | |
589 | ||
590 | This is the most wonderfulest possible qsort I can come up with (and | |
591 | still be mostly portable) My (limited) tests indicate it consistently | |
592 | does about 20% fewer calls to compare than does the qsort in the Visual | |
593 | C++ library, other vendors may vary. | |
594 | ||
595 | Some of the ideas in here can be found in "Algorithms" by Sedgewick, | |
596 | others I invented myself (or more likely re-invented since they seemed | |
597 | pretty obvious once I watched the algorithm operate for a while). | |
598 | ||
599 | Most of this code was written while watching the Marlins sweep the Giants | |
600 | in the 1997 National League Playoffs - no Braves fans allowed to use this | |
601 | code (just kidding :-). | |
602 | ||
603 | I realize that if I wanted to be true to the perl tradition, the only | |
604 | comment in this file would be something like: | |
605 | ||
606 | ...they shuffled back towards the rear of the line. 'No, not at the | |
607 | rear!' the slave-driver shouted. 'Three files up. And stay there... | |
608 | ||
609 | However, I really needed to violate that tradition just so I could keep | |
610 | track of what happens myself, not to mention some poor fool trying to | |
611 | understand this years from now :-). | |
612 | */ | |
613 | ||
614 | /* ********************************************************** Configuration */ | |
615 | ||
616 | #ifndef QSORT_ORDER_GUESS | |
617 | #define QSORT_ORDER_GUESS 2 /* Select doubling version of the netBSD trick */ | |
618 | #endif | |
619 | ||
620 | /* QSORT_MAX_STACK is the largest number of partitions that can be stacked up for | |
621 | future processing - a good max upper bound is log base 2 of memory size | |
622 | (32 on 32 bit machines, 64 on 64 bit machines, etc). In reality can | |
623 | safely be smaller than that since the program is taking up some space and | |
624 | most operating systems only let you grab some subset of contiguous | |
625 | memory (not to mention that you are normally sorting data larger than | |
626 | 1 byte element size :-). | |
627 | */ | |
628 | #ifndef QSORT_MAX_STACK | |
629 | #define QSORT_MAX_STACK 32 | |
630 | #endif | |
631 | ||
632 | /* QSORT_BREAK_EVEN is the size of the largest partition we should insertion sort. | |
633 | Anything bigger and we use qsort. If you make this too small, the qsort | |
634 | will probably break (or become less efficient), because it doesn't expect | |
635 | the middle element of a partition to be the same as the right or left - | |
636 | you have been warned). | |
637 | */ | |
638 | #ifndef QSORT_BREAK_EVEN | |
639 | #define QSORT_BREAK_EVEN 6 | |
640 | #endif | |
641 | ||
4eb872f6 JL |
642 | /* QSORT_PLAY_SAFE is the size of the largest partition we're willing |
643 | to go quadratic on. We innoculate larger partitions against | |
644 | quadratic behavior by shuffling them before sorting. This is not | |
645 | an absolute guarantee of non-quadratic behavior, but it would take | |
646 | staggeringly bad luck to pick extreme elements as the pivot | |
647 | from randomized data. | |
648 | */ | |
649 | #ifndef QSORT_PLAY_SAFE | |
650 | #define QSORT_PLAY_SAFE 255 | |
651 | #endif | |
652 | ||
84d4ea48 JH |
653 | /* ************************************************************* Data Types */ |
654 | ||
655 | /* hold left and right index values of a partition waiting to be sorted (the | |
656 | partition includes both left and right - right is NOT one past the end or | |
657 | anything like that). | |
658 | */ | |
659 | struct partition_stack_entry { | |
660 | int left; | |
661 | int right; | |
662 | #ifdef QSORT_ORDER_GUESS | |
663 | int qsort_break_even; | |
664 | #endif | |
665 | }; | |
666 | ||
667 | /* ******************************************************* Shorthand Macros */ | |
668 | ||
669 | /* Note that these macros will be used from inside the qsort function where | |
670 | we happen to know that the variable 'elt_size' contains the size of an | |
671 | array element and the variable 'temp' points to enough space to hold a | |
672 | temp element and the variable 'array' points to the array being sorted | |
673 | and 'compare' is the pointer to the compare routine. | |
674 | ||
675 | Also note that there are very many highly architecture specific ways | |
676 | these might be sped up, but this is simply the most generally portable | |
677 | code I could think of. | |
678 | */ | |
679 | ||
680 | /* Return < 0 == 0 or > 0 as the value of elt1 is < elt2, == elt2, > elt2 | |
681 | */ | |
682 | #define qsort_cmp(elt1, elt2) \ | |
683 | ((*compare)(aTHX_ array[elt1], array[elt2])) | |
684 | ||
685 | #ifdef QSORT_ORDER_GUESS | |
686 | #define QSORT_NOTICE_SWAP swapped++; | |
687 | #else | |
688 | #define QSORT_NOTICE_SWAP | |
689 | #endif | |
690 | ||
691 | /* swaps contents of array elements elt1, elt2. | |
692 | */ | |
693 | #define qsort_swap(elt1, elt2) \ | |
694 | STMT_START { \ | |
695 | QSORT_NOTICE_SWAP \ | |
696 | temp = array[elt1]; \ | |
697 | array[elt1] = array[elt2]; \ | |
698 | array[elt2] = temp; \ | |
699 | } STMT_END | |
700 | ||
701 | /* rotate contents of elt1, elt2, elt3 such that elt1 gets elt2, elt2 gets | |
702 | elt3 and elt3 gets elt1. | |
703 | */ | |
704 | #define qsort_rotate(elt1, elt2, elt3) \ | |
705 | STMT_START { \ | |
706 | QSORT_NOTICE_SWAP \ | |
707 | temp = array[elt1]; \ | |
708 | array[elt1] = array[elt2]; \ | |
709 | array[elt2] = array[elt3]; \ | |
710 | array[elt3] = temp; \ | |
711 | } STMT_END | |
712 | ||
713 | /* ************************************************************ Debug stuff */ | |
714 | ||
715 | #ifdef QSORT_DEBUG | |
716 | ||
717 | static void | |
718 | break_here() | |
719 | { | |
720 | return; /* good place to set a breakpoint */ | |
721 | } | |
722 | ||
723 | #define qsort_assert(t) (void)( (t) || (break_here(), 0) ) | |
724 | ||
725 | static void | |
726 | doqsort_all_asserts( | |
727 | void * array, | |
728 | size_t num_elts, | |
729 | size_t elt_size, | |
730 | int (*compare)(const void * elt1, const void * elt2), | |
731 | int pc_left, int pc_right, int u_left, int u_right) | |
732 | { | |
733 | int i; | |
734 | ||
735 | qsort_assert(pc_left <= pc_right); | |
736 | qsort_assert(u_right < pc_left); | |
737 | qsort_assert(pc_right < u_left); | |
738 | for (i = u_right + 1; i < pc_left; ++i) { | |
739 | qsort_assert(qsort_cmp(i, pc_left) < 0); | |
740 | } | |
741 | for (i = pc_left; i < pc_right; ++i) { | |
742 | qsort_assert(qsort_cmp(i, pc_right) == 0); | |
743 | } | |
744 | for (i = pc_right + 1; i < u_left; ++i) { | |
745 | qsort_assert(qsort_cmp(pc_right, i) < 0); | |
746 | } | |
747 | } | |
748 | ||
749 | #define qsort_all_asserts(PC_LEFT, PC_RIGHT, U_LEFT, U_RIGHT) \ | |
750 | doqsort_all_asserts(array, num_elts, elt_size, compare, \ | |
751 | PC_LEFT, PC_RIGHT, U_LEFT, U_RIGHT) | |
752 | ||
753 | #else | |
754 | ||
755 | #define qsort_assert(t) ((void)0) | |
756 | ||
757 | #define qsort_all_asserts(PC_LEFT, PC_RIGHT, U_LEFT, U_RIGHT) ((void)0) | |
758 | ||
759 | #endif | |
760 | ||
761 | /* ****************************************************************** qsort */ | |
762 | ||
763 | STATIC void /* the standard unstable (u) quicksort (qsort) */ | |
764 | S_qsortsvu(pTHX_ SV ** array, size_t num_elts, SVCOMPARE_t compare) | |
765 | { | |
766 | register SV * temp; | |
84d4ea48 JH |
767 | struct partition_stack_entry partition_stack[QSORT_MAX_STACK]; |
768 | int next_stack_entry = 0; | |
84d4ea48 JH |
769 | int part_left; |
770 | int part_right; | |
771 | #ifdef QSORT_ORDER_GUESS | |
772 | int qsort_break_even; | |
773 | int swapped; | |
774 | #endif | |
775 | ||
7918f24d NC |
776 | PERL_ARGS_ASSERT_QSORTSVU; |
777 | ||
84d4ea48 JH |
778 | /* Make sure we actually have work to do. |
779 | */ | |
780 | if (num_elts <= 1) { | |
781 | return; | |
782 | } | |
783 | ||
4eb872f6 JL |
784 | /* Innoculate large partitions against quadratic behavior */ |
785 | if (num_elts > QSORT_PLAY_SAFE) { | |
901017d6 AL |
786 | register size_t n; |
787 | register SV ** const q = array; | |
788 | for (n = num_elts; n > 1; ) { | |
789 | register const size_t j = (size_t)(n-- * Drand01()); | |
4eb872f6 JL |
790 | temp = q[j]; |
791 | q[j] = q[n]; | |
792 | q[n] = temp; | |
793 | } | |
794 | } | |
795 | ||
84d4ea48 JH |
796 | /* Setup the initial partition definition and fall into the sorting loop |
797 | */ | |
798 | part_left = 0; | |
799 | part_right = (int)(num_elts - 1); | |
800 | #ifdef QSORT_ORDER_GUESS | |
801 | qsort_break_even = QSORT_BREAK_EVEN; | |
802 | #else | |
803 | #define qsort_break_even QSORT_BREAK_EVEN | |
804 | #endif | |
805 | for ( ; ; ) { | |
806 | if ((part_right - part_left) >= qsort_break_even) { | |
807 | /* OK, this is gonna get hairy, so lets try to document all the | |
808 | concepts and abbreviations and variables and what they keep | |
809 | track of: | |
810 | ||
811 | pc: pivot chunk - the set of array elements we accumulate in the | |
812 | middle of the partition, all equal in value to the original | |
813 | pivot element selected. The pc is defined by: | |
814 | ||
815 | pc_left - the leftmost array index of the pc | |
816 | pc_right - the rightmost array index of the pc | |
817 | ||
818 | we start with pc_left == pc_right and only one element | |
819 | in the pivot chunk (but it can grow during the scan). | |
820 | ||
821 | u: uncompared elements - the set of elements in the partition | |
822 | we have not yet compared to the pivot value. There are two | |
823 | uncompared sets during the scan - one to the left of the pc | |
824 | and one to the right. | |
825 | ||
826 | u_right - the rightmost index of the left side's uncompared set | |
827 | u_left - the leftmost index of the right side's uncompared set | |
828 | ||
829 | The leftmost index of the left sides's uncompared set | |
830 | doesn't need its own variable because it is always defined | |
831 | by the leftmost edge of the whole partition (part_left). The | |
832 | same goes for the rightmost edge of the right partition | |
833 | (part_right). | |
834 | ||
835 | We know there are no uncompared elements on the left once we | |
836 | get u_right < part_left and no uncompared elements on the | |
837 | right once u_left > part_right. When both these conditions | |
838 | are met, we have completed the scan of the partition. | |
839 | ||
840 | Any elements which are between the pivot chunk and the | |
841 | uncompared elements should be less than the pivot value on | |
842 | the left side and greater than the pivot value on the right | |
843 | side (in fact, the goal of the whole algorithm is to arrange | |
844 | for that to be true and make the groups of less-than and | |
845 | greater-then elements into new partitions to sort again). | |
846 | ||
847 | As you marvel at the complexity of the code and wonder why it | |
848 | has to be so confusing. Consider some of the things this level | |
849 | of confusion brings: | |
850 | ||
851 | Once I do a compare, I squeeze every ounce of juice out of it. I | |
852 | never do compare calls I don't have to do, and I certainly never | |
853 | do redundant calls. | |
854 | ||
855 | I also never swap any elements unless I can prove there is a | |
856 | good reason. Many sort algorithms will swap a known value with | |
857 | an uncompared value just to get things in the right place (or | |
858 | avoid complexity :-), but that uncompared value, once it gets | |
859 | compared, may then have to be swapped again. A lot of the | |
860 | complexity of this code is due to the fact that it never swaps | |
861 | anything except compared values, and it only swaps them when the | |
862 | compare shows they are out of position. | |
863 | */ | |
864 | int pc_left, pc_right; | |
865 | int u_right, u_left; | |
866 | ||
867 | int s; | |
868 | ||
869 | pc_left = ((part_left + part_right) / 2); | |
870 | pc_right = pc_left; | |
871 | u_right = pc_left - 1; | |
872 | u_left = pc_right + 1; | |
873 | ||
874 | /* Qsort works best when the pivot value is also the median value | |
875 | in the partition (unfortunately you can't find the median value | |
876 | without first sorting :-), so to give the algorithm a helping | |
877 | hand, we pick 3 elements and sort them and use the median value | |
878 | of that tiny set as the pivot value. | |
879 | ||
880 | Some versions of qsort like to use the left middle and right as | |
881 | the 3 elements to sort so they can insure the ends of the | |
882 | partition will contain values which will stop the scan in the | |
883 | compare loop, but when you have to call an arbitrarily complex | |
884 | routine to do a compare, its really better to just keep track of | |
885 | array index values to know when you hit the edge of the | |
886 | partition and avoid the extra compare. An even better reason to | |
887 | avoid using a compare call is the fact that you can drop off the | |
888 | edge of the array if someone foolishly provides you with an | |
889 | unstable compare function that doesn't always provide consistent | |
890 | results. | |
891 | ||
892 | So, since it is simpler for us to compare the three adjacent | |
893 | elements in the middle of the partition, those are the ones we | |
894 | pick here (conveniently pointed at by u_right, pc_left, and | |
895 | u_left). The values of the left, center, and right elements | |
896 | are refered to as l c and r in the following comments. | |
897 | */ | |
898 | ||
899 | #ifdef QSORT_ORDER_GUESS | |
900 | swapped = 0; | |
901 | #endif | |
902 | s = qsort_cmp(u_right, pc_left); | |
903 | if (s < 0) { | |
904 | /* l < c */ | |
905 | s = qsort_cmp(pc_left, u_left); | |
906 | /* if l < c, c < r - already in order - nothing to do */ | |
907 | if (s == 0) { | |
908 | /* l < c, c == r - already in order, pc grows */ | |
909 | ++pc_right; | |
910 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
911 | } else if (s > 0) { | |
912 | /* l < c, c > r - need to know more */ | |
913 | s = qsort_cmp(u_right, u_left); | |
914 | if (s < 0) { | |
915 | /* l < c, c > r, l < r - swap c & r to get ordered */ | |
916 | qsort_swap(pc_left, u_left); | |
917 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
918 | } else if (s == 0) { | |
919 | /* l < c, c > r, l == r - swap c&r, grow pc */ | |
920 | qsort_swap(pc_left, u_left); | |
921 | --pc_left; | |
922 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
923 | } else { | |
924 | /* l < c, c > r, l > r - make lcr into rlc to get ordered */ | |
925 | qsort_rotate(pc_left, u_right, u_left); | |
926 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
927 | } | |
928 | } | |
929 | } else if (s == 0) { | |
930 | /* l == c */ | |
931 | s = qsort_cmp(pc_left, u_left); | |
932 | if (s < 0) { | |
933 | /* l == c, c < r - already in order, grow pc */ | |
934 | --pc_left; | |
935 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
936 | } else if (s == 0) { | |
937 | /* l == c, c == r - already in order, grow pc both ways */ | |
938 | --pc_left; | |
939 | ++pc_right; | |
940 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
941 | } else { | |
942 | /* l == c, c > r - swap l & r, grow pc */ | |
943 | qsort_swap(u_right, u_left); | |
944 | ++pc_right; | |
945 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
946 | } | |
947 | } else { | |
948 | /* l > c */ | |
949 | s = qsort_cmp(pc_left, u_left); | |
950 | if (s < 0) { | |
951 | /* l > c, c < r - need to know more */ | |
952 | s = qsort_cmp(u_right, u_left); | |
953 | if (s < 0) { | |
954 | /* l > c, c < r, l < r - swap l & c to get ordered */ | |
955 | qsort_swap(u_right, pc_left); | |
956 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
957 | } else if (s == 0) { | |
958 | /* l > c, c < r, l == r - swap l & c, grow pc */ | |
959 | qsort_swap(u_right, pc_left); | |
960 | ++pc_right; | |
961 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
962 | } else { | |
963 | /* l > c, c < r, l > r - rotate lcr into crl to order */ | |
964 | qsort_rotate(u_right, pc_left, u_left); | |
965 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
966 | } | |
967 | } else if (s == 0) { | |
968 | /* l > c, c == r - swap ends, grow pc */ | |
969 | qsort_swap(u_right, u_left); | |
970 | --pc_left; | |
971 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
972 | } else { | |
973 | /* l > c, c > r - swap ends to get in order */ | |
974 | qsort_swap(u_right, u_left); | |
975 | qsort_all_asserts(pc_left, pc_right, u_left + 1, u_right - 1); | |
976 | } | |
977 | } | |
978 | /* We now know the 3 middle elements have been compared and | |
979 | arranged in the desired order, so we can shrink the uncompared | |
980 | sets on both sides | |
981 | */ | |
982 | --u_right; | |
983 | ++u_left; | |
984 | qsort_all_asserts(pc_left, pc_right, u_left, u_right); | |
985 | ||
986 | /* The above massive nested if was the simple part :-). We now have | |
987 | the middle 3 elements ordered and we need to scan through the | |
988 | uncompared sets on either side, swapping elements that are on | |
989 | the wrong side or simply shuffling equal elements around to get | |
990 | all equal elements into the pivot chunk. | |
991 | */ | |
992 | ||
993 | for ( ; ; ) { | |
994 | int still_work_on_left; | |
995 | int still_work_on_right; | |
996 | ||
997 | /* Scan the uncompared values on the left. If I find a value | |
998 | equal to the pivot value, move it over so it is adjacent to | |
999 | the pivot chunk and expand the pivot chunk. If I find a value | |
1000 | less than the pivot value, then just leave it - its already | |
1001 | on the correct side of the partition. If I find a greater | |
1002 | value, then stop the scan. | |
1003 | */ | |
1004 | while ((still_work_on_left = (u_right >= part_left))) { | |
1005 | s = qsort_cmp(u_right, pc_left); | |
1006 | if (s < 0) { | |
1007 | --u_right; | |
1008 | } else if (s == 0) { | |
1009 | --pc_left; | |
1010 | if (pc_left != u_right) { | |
1011 | qsort_swap(u_right, pc_left); | |
1012 | } | |
1013 | --u_right; | |
1014 | } else { | |
1015 | break; | |
1016 | } | |
1017 | qsort_assert(u_right < pc_left); | |
1018 | qsort_assert(pc_left <= pc_right); | |
1019 | qsort_assert(qsort_cmp(u_right + 1, pc_left) <= 0); | |
1020 | qsort_assert(qsort_cmp(pc_left, pc_right) == 0); | |
1021 | } | |
1022 | ||
1023 | /* Do a mirror image scan of uncompared values on the right | |
1024 | */ | |
1025 | while ((still_work_on_right = (u_left <= part_right))) { | |
1026 | s = qsort_cmp(pc_right, u_left); | |
1027 | if (s < 0) { | |
1028 | ++u_left; | |
1029 | } else if (s == 0) { | |
1030 | ++pc_right; | |
1031 | if (pc_right != u_left) { | |
1032 | qsort_swap(pc_right, u_left); | |
1033 | } | |
1034 | ++u_left; | |
1035 | } else { | |
1036 | break; | |
1037 | } | |
1038 | qsort_assert(u_left > pc_right); | |
1039 | qsort_assert(pc_left <= pc_right); | |
1040 | qsort_assert(qsort_cmp(pc_right, u_left - 1) <= 0); | |
1041 | qsort_assert(qsort_cmp(pc_left, pc_right) == 0); | |
1042 | } | |
1043 | ||
1044 | if (still_work_on_left) { | |
1045 | /* I know I have a value on the left side which needs to be | |
1046 | on the right side, but I need to know more to decide | |
1047 | exactly the best thing to do with it. | |
1048 | */ | |
1049 | if (still_work_on_right) { | |
1050 | /* I know I have values on both side which are out of | |
1051 | position. This is a big win because I kill two birds | |
1052 | with one swap (so to speak). I can advance the | |
1053 | uncompared pointers on both sides after swapping both | |
1054 | of them into the right place. | |
1055 | */ | |
1056 | qsort_swap(u_right, u_left); | |
1057 | --u_right; | |
1058 | ++u_left; | |
1059 | qsort_all_asserts(pc_left, pc_right, u_left, u_right); | |
1060 | } else { | |
1061 | /* I have an out of position value on the left, but the | |
1062 | right is fully scanned, so I "slide" the pivot chunk | |
1063 | and any less-than values left one to make room for the | |
1064 | greater value over on the right. If the out of position | |
1065 | value is immediately adjacent to the pivot chunk (there | |
1066 | are no less-than values), I can do that with a swap, | |
1067 | otherwise, I have to rotate one of the less than values | |
1068 | into the former position of the out of position value | |
1069 | and the right end of the pivot chunk into the left end | |
1070 | (got all that?). | |
1071 | */ | |
1072 | --pc_left; | |
1073 | if (pc_left == u_right) { | |
1074 | qsort_swap(u_right, pc_right); | |
1075 | qsort_all_asserts(pc_left, pc_right-1, u_left, u_right-1); | |
1076 | } else { | |
1077 | qsort_rotate(u_right, pc_left, pc_right); | |
1078 | qsort_all_asserts(pc_left, pc_right-1, u_left, u_right-1); | |
1079 | } | |
1080 | --pc_right; | |
1081 | --u_right; | |
1082 | } | |
1083 | } else if (still_work_on_right) { | |
1084 | /* Mirror image of complex case above: I have an out of | |
1085 | position value on the right, but the left is fully | |
1086 | scanned, so I need to shuffle things around to make room | |
1087 | for the right value on the left. | |
1088 | */ | |
1089 | ++pc_right; | |
1090 | if (pc_right == u_left) { | |
1091 | qsort_swap(u_left, pc_left); | |
1092 | qsort_all_asserts(pc_left+1, pc_right, u_left+1, u_right); | |
1093 | } else { | |
1094 | qsort_rotate(pc_right, pc_left, u_left); | |
1095 | qsort_all_asserts(pc_left+1, pc_right, u_left+1, u_right); | |
1096 | } | |
1097 | ++pc_left; | |
1098 | ++u_left; | |
1099 | } else { | |
1100 | /* No more scanning required on either side of partition, | |
1101 | break out of loop and figure out next set of partitions | |
1102 | */ | |
1103 | break; | |
1104 | } | |
1105 | } | |
1106 | ||
1107 | /* The elements in the pivot chunk are now in the right place. They | |
1108 | will never move or be compared again. All I have to do is decide | |
1109 | what to do with the stuff to the left and right of the pivot | |
1110 | chunk. | |
1111 | ||
1112 | Notes on the QSORT_ORDER_GUESS ifdef code: | |
1113 | ||
1114 | 1. If I just built these partitions without swapping any (or | |
1115 | very many) elements, there is a chance that the elements are | |
1116 | already ordered properly (being properly ordered will | |
1117 | certainly result in no swapping, but the converse can't be | |
1118 | proved :-). | |
1119 | ||
1120 | 2. A (properly written) insertion sort will run faster on | |
1121 | already ordered data than qsort will. | |
1122 | ||
1123 | 3. Perhaps there is some way to make a good guess about | |
1124 | switching to an insertion sort earlier than partition size 6 | |
1125 | (for instance - we could save the partition size on the stack | |
1126 | and increase the size each time we find we didn't swap, thus | |
1127 | switching to insertion sort earlier for partitions with a | |
1128 | history of not swapping). | |
1129 | ||
1130 | 4. Naturally, if I just switch right away, it will make | |
1131 | artificial benchmarks with pure ascending (or descending) | |
1132 | data look really good, but is that a good reason in general? | |
1133 | Hard to say... | |
1134 | */ | |
1135 | ||
1136 | #ifdef QSORT_ORDER_GUESS | |
1137 | if (swapped < 3) { | |
1138 | #if QSORT_ORDER_GUESS == 1 | |
1139 | qsort_break_even = (part_right - part_left) + 1; | |
1140 | #endif | |
1141 | #if QSORT_ORDER_GUESS == 2 | |
1142 | qsort_break_even *= 2; | |
1143 | #endif | |
1144 | #if QSORT_ORDER_GUESS == 3 | |
901017d6 | 1145 | const int prev_break = qsort_break_even; |
84d4ea48 JH |
1146 | qsort_break_even *= qsort_break_even; |
1147 | if (qsort_break_even < prev_break) { | |
1148 | qsort_break_even = (part_right - part_left) + 1; | |
1149 | } | |
1150 | #endif | |
1151 | } else { | |
1152 | qsort_break_even = QSORT_BREAK_EVEN; | |
1153 | } | |
1154 | #endif | |
1155 | ||
1156 | if (part_left < pc_left) { | |
1157 | /* There are elements on the left which need more processing. | |
1158 | Check the right as well before deciding what to do. | |
1159 | */ | |
1160 | if (pc_right < part_right) { | |
1161 | /* We have two partitions to be sorted. Stack the biggest one | |
1162 | and process the smallest one on the next iteration. This | |
1163 | minimizes the stack height by insuring that any additional | |
1164 | stack entries must come from the smallest partition which | |
1165 | (because it is smallest) will have the fewest | |
1166 | opportunities to generate additional stack entries. | |
1167 | */ | |
1168 | if ((part_right - pc_right) > (pc_left - part_left)) { | |
1169 | /* stack the right partition, process the left */ | |
1170 | partition_stack[next_stack_entry].left = pc_right + 1; | |
1171 | partition_stack[next_stack_entry].right = part_right; | |
1172 | #ifdef QSORT_ORDER_GUESS | |
1173 | partition_stack[next_stack_entry].qsort_break_even = qsort_break_even; | |
1174 | #endif | |
1175 | part_right = pc_left - 1; | |
1176 | } else { | |
1177 | /* stack the left partition, process the right */ | |
1178 | partition_stack[next_stack_entry].left = part_left; | |
1179 | partition_stack[next_stack_entry].right = pc_left - 1; | |
1180 | #ifdef QSORT_ORDER_GUESS | |
1181 | partition_stack[next_stack_entry].qsort_break_even = qsort_break_even; | |
1182 | #endif | |
1183 | part_left = pc_right + 1; | |
1184 | } | |
1185 | qsort_assert(next_stack_entry < QSORT_MAX_STACK); | |
1186 | ++next_stack_entry; | |
1187 | } else { | |
1188 | /* The elements on the left are the only remaining elements | |
1189 | that need sorting, arrange for them to be processed as the | |
1190 | next partition. | |
1191 | */ | |
1192 | part_right = pc_left - 1; | |
1193 | } | |
1194 | } else if (pc_right < part_right) { | |
1195 | /* There is only one chunk on the right to be sorted, make it | |
1196 | the new partition and loop back around. | |
1197 | */ | |
1198 | part_left = pc_right + 1; | |
1199 | } else { | |
1200 | /* This whole partition wound up in the pivot chunk, so | |
1201 | we need to get a new partition off the stack. | |
1202 | */ | |
1203 | if (next_stack_entry == 0) { | |
1204 | /* the stack is empty - we are done */ | |
1205 | break; | |
1206 | } | |
1207 | --next_stack_entry; | |
1208 | part_left = partition_stack[next_stack_entry].left; | |
1209 | part_right = partition_stack[next_stack_entry].right; | |
1210 | #ifdef QSORT_ORDER_GUESS | |
1211 | qsort_break_even = partition_stack[next_stack_entry].qsort_break_even; | |
1212 | #endif | |
1213 | } | |
1214 | } else { | |
1215 | /* This partition is too small to fool with qsort complexity, just | |
1216 | do an ordinary insertion sort to minimize overhead. | |
1217 | */ | |
1218 | int i; | |
1219 | /* Assume 1st element is in right place already, and start checking | |
1220 | at 2nd element to see where it should be inserted. | |
1221 | */ | |
1222 | for (i = part_left + 1; i <= part_right; ++i) { | |
1223 | int j; | |
1224 | /* Scan (backwards - just in case 'i' is already in right place) | |
1225 | through the elements already sorted to see if the ith element | |
1226 | belongs ahead of one of them. | |
1227 | */ | |
1228 | for (j = i - 1; j >= part_left; --j) { | |
1229 | if (qsort_cmp(i, j) >= 0) { | |
1230 | /* i belongs right after j | |
1231 | */ | |
1232 | break; | |
1233 | } | |
1234 | } | |
1235 | ++j; | |
1236 | if (j != i) { | |
1237 | /* Looks like we really need to move some things | |
1238 | */ | |
1239 | int k; | |
1240 | temp = array[i]; | |
1241 | for (k = i - 1; k >= j; --k) | |
1242 | array[k + 1] = array[k]; | |
1243 | array[j] = temp; | |
1244 | } | |
1245 | } | |
1246 | ||
1247 | /* That partition is now sorted, grab the next one, or get out | |
1248 | of the loop if there aren't any more. | |
1249 | */ | |
1250 | ||
1251 | if (next_stack_entry == 0) { | |
1252 | /* the stack is empty - we are done */ | |
1253 | break; | |
1254 | } | |
1255 | --next_stack_entry; | |
1256 | part_left = partition_stack[next_stack_entry].left; | |
1257 | part_right = partition_stack[next_stack_entry].right; | |
1258 | #ifdef QSORT_ORDER_GUESS | |
1259 | qsort_break_even = partition_stack[next_stack_entry].qsort_break_even; | |
1260 | #endif | |
1261 | } | |
1262 | } | |
1263 | ||
1264 | /* Believe it or not, the array is sorted at this point! */ | |
1265 | } | |
1266 | ||
84d4ea48 JH |
1267 | /* Stabilize what is, presumably, an otherwise unstable sort method. |
1268 | * We do that by allocating (or having on hand) an array of pointers | |
1269 | * that is the same size as the original array of elements to be sorted. | |
1270 | * We initialize this parallel array with the addresses of the original | |
1271 | * array elements. This indirection can make you crazy. | |
1272 | * Some pictures can help. After initializing, we have | |
1273 | * | |
1274 | * indir list1 | |
1275 | * +----+ +----+ | |
1276 | * | | --------------> | | ------> first element to be sorted | |
1277 | * +----+ +----+ | |
1278 | * | | --------------> | | ------> second element to be sorted | |
1279 | * +----+ +----+ | |
1280 | * | | --------------> | | ------> third element to be sorted | |
1281 | * +----+ +----+ | |
1282 | * ... | |
1283 | * +----+ +----+ | |
1284 | * | | --------------> | | ------> n-1st element to be sorted | |
1285 | * +----+ +----+ | |
1286 | * | | --------------> | | ------> n-th element to be sorted | |
1287 | * +----+ +----+ | |
1288 | * | |
1289 | * During the sort phase, we leave the elements of list1 where they are, | |
1290 | * and sort the pointers in the indirect array in the same order determined | |
1291 | * by the original comparison routine on the elements pointed to. | |
1292 | * Because we don't move the elements of list1 around through | |
1293 | * this phase, we can break ties on elements that compare equal | |
1294 | * using their address in the list1 array, ensuring stabilty. | |
1295 | * This leaves us with something looking like | |
1296 | * | |
1297 | * indir list1 | |
1298 | * +----+ +----+ | |
1299 | * | | --+ +---> | | ------> first element to be sorted | |
1300 | * +----+ | | +----+ | |
1301 | * | | --|-------|---> | | ------> second element to be sorted | |
1302 | * +----+ | | +----+ | |
1303 | * | | --|-------+ +-> | | ------> third element to be sorted | |
1304 | * +----+ | | +----+ | |
1305 | * ... | |
1306 | * +----+ | | | | +----+ | |
1307 | * | | ---|-+ | +--> | | ------> n-1st element to be sorted | |
1308 | * +----+ | | +----+ | |
1309 | * | | ---+ +----> | | ------> n-th element to be sorted | |
1310 | * +----+ +----+ | |
1311 | * | |
1312 | * where the i-th element of the indirect array points to the element | |
1313 | * that should be i-th in the sorted array. After the sort phase, | |
1314 | * we have to put the elements of list1 into the places | |
1315 | * dictated by the indirect array. | |
1316 | */ | |
1317 | ||
84d4ea48 JH |
1318 | |
1319 | static I32 | |
31e9e0a3 | 1320 | cmpindir(pTHX_ gptr const a, gptr const b) |
84d4ea48 | 1321 | { |
97aff369 | 1322 | dVAR; |
901017d6 AL |
1323 | gptr * const ap = (gptr *)a; |
1324 | gptr * const bp = (gptr *)b; | |
0bcc34c2 | 1325 | const I32 sense = PL_sort_RealCmp(aTHX_ *ap, *bp); |
84d4ea48 | 1326 | |
0bcc34c2 AL |
1327 | if (sense) |
1328 | return sense; | |
1329 | return (ap > bp) ? 1 : ((ap < bp) ? -1 : 0); | |
84d4ea48 JH |
1330 | } |
1331 | ||
6c3fb703 | 1332 | static I32 |
31e9e0a3 | 1333 | cmpindir_desc(pTHX_ gptr const a, gptr const b) |
6c3fb703 | 1334 | { |
97aff369 | 1335 | dVAR; |
901017d6 AL |
1336 | gptr * const ap = (gptr *)a; |
1337 | gptr * const bp = (gptr *)b; | |
0bcc34c2 | 1338 | const I32 sense = PL_sort_RealCmp(aTHX_ *ap, *bp); |
6c3fb703 NC |
1339 | |
1340 | /* Reverse the default */ | |
0bcc34c2 | 1341 | if (sense) |
6c3fb703 NC |
1342 | return -sense; |
1343 | /* But don't reverse the stability test. */ | |
1344 | return (ap > bp) ? 1 : ((ap < bp) ? -1 : 0); | |
1345 | ||
1346 | } | |
1347 | ||
84d4ea48 | 1348 | STATIC void |
6c3fb703 | 1349 | S_qsortsv(pTHX_ gptr *list1, size_t nmemb, SVCOMPARE_t cmp, U32 flags) |
84d4ea48 | 1350 | { |
97aff369 | 1351 | dVAR; |
7b9ef140 | 1352 | if ((flags & SORTf_STABLE) != 0) { |
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; | |
a02a5408 | 1361 | else { Newx(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 */ |
fe2ae508 AL |
1370 | if (flags & SORTf_DESC) |
1371 | qsortsvu((gptr *)indir, nmemb, cmpindir_desc); | |
1372 | else | |
1373 | qsortsvu((gptr *)indir, nmemb, cmpindir); | |
4eb872f6 | 1374 | |
84d4ea48 JH |
1375 | pp = indir; |
1376 | q = list1; | |
1377 | for (n = nmemb; n--; ) { | |
1378 | /* Assert A: all elements of q with index > n are already | |
1379 | * in place. This is vacuosly true at the start, and we | |
1380 | * put element n where it belongs below (if it wasn't | |
1381 | * already where it belonged). Assert B: we only move | |
1382 | * elements that aren't where they belong, | |
1383 | * so, by A, we never tamper with elements above n. | |
1384 | */ | |
1385 | j = pp[n] - q; /* This sets j so that q[j] is | |
1386 | * at pp[n]. *pp[j] belongs in | |
1387 | * q[j], by construction. | |
1388 | */ | |
1389 | if (n != j) { /* all's well if n == j */ | |
1390 | tmp = q[j]; /* save what's in q[j] */ | |
1391 | do { | |
1392 | q[j] = *pp[j]; /* put *pp[j] where it belongs */ | |
1393 | i = pp[j] - q; /* the index in q of the element | |
1394 | * just moved */ | |
1395 | pp[j] = q + j; /* this is ok now */ | |
1396 | } while ((j = i) != n); | |
1397 | /* There are only finitely many (nmemb) addresses | |
1398 | * in the pp array. | |
1399 | * So we must eventually revisit an index we saw before. | |
1400 | * Suppose the first revisited index is k != n. | |
1401 | * An index is visited because something else belongs there. | |
1402 | * If we visit k twice, then two different elements must | |
1403 | * belong in the same place, which cannot be. | |
1404 | * So j must get back to n, the loop terminates, | |
1405 | * and we put the saved element where it belongs. | |
1406 | */ | |
1407 | q[n] = tmp; /* put what belongs into | |
1408 | * the n-th element */ | |
1409 | } | |
1410 | } | |
1411 | ||
1412 | /* free iff allocated */ | |
1413 | if (indir != small) { Safefree(indir); } | |
1414 | /* restore prevailing comparison routine */ | |
147f47de | 1415 | PL_sort_RealCmp = savecmp; |
7b9ef140 | 1416 | } else if ((flags & SORTf_DESC) != 0) { |
d4c19fe8 | 1417 | const SVCOMPARE_t savecmp = PL_sort_RealCmp; /* Save current comparison routine, if any */ |
6c3fb703 NC |
1418 | PL_sort_RealCmp = cmp; /* Put comparison routine where cmp_desc can find it */ |
1419 | cmp = cmp_desc; | |
fe2ae508 | 1420 | qsortsvu(list1, nmemb, cmp); |
6c3fb703 NC |
1421 | /* restore prevailing comparison routine */ |
1422 | PL_sort_RealCmp = savecmp; | |
c53fc8a6 | 1423 | } else { |
fe2ae508 | 1424 | qsortsvu(list1, nmemb, cmp); |
84d4ea48 JH |
1425 | } |
1426 | } | |
4eb872f6 JL |
1427 | |
1428 | /* | |
ccfc67b7 JH |
1429 | =head1 Array Manipulation Functions |
1430 | ||
84d4ea48 JH |
1431 | =for apidoc sortsv |
1432 | ||
1433 | Sort an array. Here is an example: | |
1434 | ||
4eb872f6 | 1435 | sortsv(AvARRAY(av), av_len(av)+1, Perl_sv_cmp_locale); |
84d4ea48 | 1436 | |
7b9ef140 RH |
1437 | Currently this always uses mergesort. See sortsv_flags for a more |
1438 | flexible routine. | |
78210658 | 1439 | |
84d4ea48 JH |
1440 | =cut |
1441 | */ | |
4eb872f6 | 1442 | |
84d4ea48 JH |
1443 | void |
1444 | Perl_sortsv(pTHX_ SV **array, size_t nmemb, SVCOMPARE_t cmp) | |
1445 | { | |
7918f24d NC |
1446 | PERL_ARGS_ASSERT_SORTSV; |
1447 | ||
7b9ef140 | 1448 | sortsv_flags(array, nmemb, cmp, 0); |
6c3fb703 NC |
1449 | } |
1450 | ||
7b9ef140 RH |
1451 | /* |
1452 | =for apidoc sortsv_flags | |
6c3fb703 | 1453 | |
7b9ef140 RH |
1454 | Sort an array, with various options. |
1455 | ||
1456 | =cut | |
1457 | */ | |
1458 | void | |
1459 | Perl_sortsv_flags(pTHX_ SV **array, size_t nmemb, SVCOMPARE_t cmp, U32 flags) | |
6c3fb703 | 1460 | { |
7918f24d NC |
1461 | PERL_ARGS_ASSERT_SORTSV_FLAGS; |
1462 | ||
d4c19fe8 AL |
1463 | if (flags & SORTf_QSORT) |
1464 | S_qsortsv(aTHX_ array, nmemb, cmp, flags); | |
1465 | else | |
1466 | S_mergesortsv(aTHX_ array, nmemb, cmp, flags); | |
84d4ea48 JH |
1467 | } |
1468 | ||
4d562308 SF |
1469 | #define SvNSIOK(sv) ((SvFLAGS(sv) & SVf_NOK) || ((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV)) == SVf_IOK)) |
1470 | #define SvSIOK(sv) ((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV)) == SVf_IOK) | |
1471 | #define SvNSIV(sv) ( SvNOK(sv) ? SvNVX(sv) : ( SvSIOK(sv) ? SvIVX(sv) : sv_2nv(sv) ) ) | |
1472 | ||
84d4ea48 JH |
1473 | PP(pp_sort) |
1474 | { | |
27da23d5 | 1475 | dVAR; dSP; dMARK; dORIGMARK; |
fe1bc4cf DM |
1476 | register SV **p1 = ORIGMARK+1, **p2; |
1477 | register I32 max, i; | |
7d49f689 | 1478 | AV* av = NULL; |
84d4ea48 JH |
1479 | HV *stash; |
1480 | GV *gv; | |
cbbf8932 | 1481 | CV *cv = NULL; |
84d4ea48 | 1482 | I32 gimme = GIMME; |
0bcc34c2 | 1483 | OP* const nextop = PL_op->op_next; |
84d4ea48 JH |
1484 | I32 overloading = 0; |
1485 | bool hasargs = FALSE; | |
1486 | I32 is_xsub = 0; | |
fe1bc4cf | 1487 | I32 sorting_av = 0; |
901017d6 AL |
1488 | const U8 priv = PL_op->op_private; |
1489 | const U8 flags = PL_op->op_flags; | |
7b9ef140 RH |
1490 | U32 sort_flags = 0; |
1491 | void (*sortsvp)(pTHX_ SV **array, size_t nmemb, SVCOMPARE_t cmp, U32 flags) | |
1492 | = Perl_sortsv_flags; | |
4d562308 | 1493 | I32 all_SIVs = 1; |
84d4ea48 | 1494 | |
7b9ef140 RH |
1495 | if ((priv & OPpSORT_DESCEND) != 0) |
1496 | sort_flags |= SORTf_DESC; | |
1497 | if ((priv & OPpSORT_QSORT) != 0) | |
1498 | sort_flags |= SORTf_QSORT; | |
1499 | if ((priv & OPpSORT_STABLE) != 0) | |
1500 | sort_flags |= SORTf_STABLE; | |
1501 | ||
84d4ea48 JH |
1502 | if (gimme != G_ARRAY) { |
1503 | SP = MARK; | |
b59aed67 | 1504 | EXTEND(SP,1); |
84d4ea48 JH |
1505 | RETPUSHUNDEF; |
1506 | } | |
1507 | ||
1508 | ENTER; | |
1509 | SAVEVPTR(PL_sortcop); | |
471178c0 NC |
1510 | if (flags & OPf_STACKED) { |
1511 | if (flags & OPf_SPECIAL) { | |
84d4ea48 JH |
1512 | OP *kid = cLISTOP->op_first->op_sibling; /* pass pushmark */ |
1513 | kid = kUNOP->op_first; /* pass rv2gv */ | |
1514 | kid = kUNOP->op_first; /* pass leave */ | |
1515 | PL_sortcop = kid->op_next; | |
1516 | stash = CopSTASH(PL_curcop); | |
1517 | } | |
1518 | else { | |
1519 | cv = sv_2cv(*++MARK, &stash, &gv, 0); | |
1520 | if (cv && SvPOK(cv)) { | |
ad64d0ec | 1521 | const char * const proto = SvPV_nolen_const(MUTABLE_SV(cv)); |
84d4ea48 JH |
1522 | if (proto && strEQ(proto, "$$")) { |
1523 | hasargs = TRUE; | |
1524 | } | |
1525 | } | |
1526 | if (!(cv && CvROOT(cv))) { | |
aed2304a | 1527 | if (cv && CvISXSUB(cv)) { |
84d4ea48 JH |
1528 | is_xsub = 1; |
1529 | } | |
1530 | else if (gv) { | |
1531 | SV *tmpstr = sv_newmortal(); | |
bd61b366 | 1532 | gv_efullname3(tmpstr, gv, NULL); |
35c1215d | 1533 | DIE(aTHX_ "Undefined sort subroutine \"%"SVf"\" called", |
be2597df | 1534 | SVfARG(tmpstr)); |
84d4ea48 JH |
1535 | } |
1536 | else { | |
1537 | DIE(aTHX_ "Undefined subroutine in sort"); | |
1538 | } | |
1539 | } | |
1540 | ||
1541 | if (is_xsub) | |
1542 | PL_sortcop = (OP*)cv; | |
9850bf21 | 1543 | else |
84d4ea48 | 1544 | PL_sortcop = CvSTART(cv); |
84d4ea48 JH |
1545 | } |
1546 | } | |
1547 | else { | |
5f66b61c | 1548 | PL_sortcop = NULL; |
84d4ea48 JH |
1549 | stash = CopSTASH(PL_curcop); |
1550 | } | |
1551 | ||
fe1bc4cf DM |
1552 | /* optimiser converts "@a = sort @a" to "sort \@a"; |
1553 | * in case of tied @a, pessimise: push (@a) onto stack, then assign | |
1554 | * result back to @a at the end of this function */ | |
0723351e | 1555 | if (priv & OPpSORT_INPLACE) { |
fe1bc4cf DM |
1556 | assert( MARK+1 == SP && *SP && SvTYPE(*SP) == SVt_PVAV); |
1557 | (void)POPMARK; /* remove mark associated with ex-OP_AASSIGN */ | |
502c6561 | 1558 | av = MUTABLE_AV((*SP)); |
fe1bc4cf DM |
1559 | max = AvFILL(av) + 1; |
1560 | if (SvMAGICAL(av)) { | |
1561 | MEXTEND(SP, max); | |
fe2774ed | 1562 | for (i=0; i < max; i++) { |
fe1bc4cf | 1563 | SV **svp = av_fetch(av, i, FALSE); |
a0714e2c | 1564 | *SP++ = (svp) ? *svp : NULL; |
fe1bc4cf | 1565 | } |
62b40d24 DM |
1566 | SP--; |
1567 | p1 = p2 = SP - (max-1); | |
fe1bc4cf DM |
1568 | } |
1569 | else { | |
9850bf21 | 1570 | if (SvREADONLY(av)) |
f1f66076 | 1571 | Perl_croak(aTHX_ "%s", PL_no_modify); |
9850bf21 RH |
1572 | else |
1573 | SvREADONLY_on(av); | |
fe1bc4cf DM |
1574 | p1 = p2 = AvARRAY(av); |
1575 | sorting_av = 1; | |
1576 | } | |
1577 | } | |
1578 | else { | |
1579 | p2 = MARK+1; | |
1580 | max = SP - MARK; | |
1581 | } | |
1582 | ||
83a44efe SF |
1583 | /* shuffle stack down, removing optional initial cv (p1!=p2), plus |
1584 | * any nulls; also stringify or converting to integer or number as | |
1585 | * required any args */ | |
fe1bc4cf DM |
1586 | for (i=max; i > 0 ; i--) { |
1587 | if ((*p1 = *p2++)) { /* Weed out nulls. */ | |
1588 | SvTEMP_off(*p1); | |
83a44efe SF |
1589 | if (!PL_sortcop) { |
1590 | if (priv & OPpSORT_NUMERIC) { | |
1591 | if (priv & OPpSORT_INTEGER) { | |
1592 | if (!SvIOK(*p1)) { | |
1593 | if (SvAMAGIC(*p1)) | |
1594 | overloading = 1; | |
1595 | else | |
1596 | (void)sv_2iv(*p1); | |
1597 | } | |
1598 | } | |
1599 | else { | |
4d562308 | 1600 | if (!SvNSIOK(*p1)) { |
83a44efe SF |
1601 | if (SvAMAGIC(*p1)) |
1602 | overloading = 1; | |
1603 | else | |
1604 | (void)sv_2nv(*p1); | |
1605 | } | |
4d562308 SF |
1606 | if (all_SIVs && !SvSIOK(*p1)) |
1607 | all_SIVs = 0; | |
83a44efe SF |
1608 | } |
1609 | } | |
1610 | else { | |
1611 | if (!SvPOK(*p1)) { | |
83a44efe SF |
1612 | if (SvAMAGIC(*p1)) |
1613 | overloading = 1; | |
1614 | else | |
83003860 NC |
1615 | (void)sv_2pv_flags(*p1, 0, |
1616 | SV_GMAGIC|SV_CONST_RETURN); | |
83a44efe SF |
1617 | } |
1618 | } | |
84d4ea48 | 1619 | } |
fe1bc4cf | 1620 | p1++; |
84d4ea48 | 1621 | } |
fe1bc4cf DM |
1622 | else |
1623 | max--; | |
84d4ea48 | 1624 | } |
fe1bc4cf DM |
1625 | if (sorting_av) |
1626 | AvFILLp(av) = max-1; | |
1627 | ||
1628 | if (max > 1) { | |
471178c0 | 1629 | SV **start; |
fe1bc4cf | 1630 | if (PL_sortcop) { |
84d4ea48 JH |
1631 | PERL_CONTEXT *cx; |
1632 | SV** newsp; | |
901017d6 | 1633 | const bool oldcatch = CATCH_GET; |
84d4ea48 JH |
1634 | |
1635 | SAVETMPS; | |
1636 | SAVEOP(); | |
1637 | ||
1638 | CATCH_SET(TRUE); | |
1639 | PUSHSTACKi(PERLSI_SORT); | |
1640 | if (!hasargs && !is_xsub) { | |
9850bf21 RH |
1641 | SAVESPTR(PL_firstgv); |
1642 | SAVESPTR(PL_secondgv); | |
1643 | SAVESPTR(PL_sortstash); | |
fafc274c NC |
1644 | PL_firstgv = gv_fetchpvs("a", GV_ADD|GV_NOTQUAL, SVt_PV); |
1645 | PL_secondgv = gv_fetchpvs("b", GV_ADD|GV_NOTQUAL, SVt_PV); | |
9850bf21 | 1646 | PL_sortstash = stash; |
84d4ea48 JH |
1647 | SAVESPTR(GvSV(PL_firstgv)); |
1648 | SAVESPTR(GvSV(PL_secondgv)); | |
1649 | } | |
1650 | ||
1651 | PUSHBLOCK(cx, CXt_NULL, PL_stack_base); | |
471178c0 | 1652 | if (!(flags & OPf_SPECIAL)) { |
84d4ea48 JH |
1653 | cx->cx_type = CXt_SUB; |
1654 | cx->blk_gimme = G_SCALAR; | |
1655 | PUSHSUB(cx); | |
9850bf21 | 1656 | if (!is_xsub) { |
0bcc34c2 | 1657 | AV* const padlist = CvPADLIST(cv); |
9850bf21 RH |
1658 | |
1659 | if (++CvDEPTH(cv) >= 2) { | |
1660 | PERL_STACK_OVERFLOW_CHECK(); | |
1661 | pad_push(padlist, CvDEPTH(cv)); | |
1662 | } | |
1663 | SAVECOMPPAD(); | |
1664 | PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv)); | |
84d4ea48 | 1665 | |
9850bf21 RH |
1666 | if (hasargs) { |
1667 | /* This is mostly copied from pp_entersub */ | |
502c6561 | 1668 | AV * const av = MUTABLE_AV(PAD_SVl(0)); |
84d4ea48 | 1669 | |
9850bf21 | 1670 | cx->blk_sub.savearray = GvAV(PL_defgv); |
502c6561 | 1671 | GvAV(PL_defgv) = MUTABLE_AV(SvREFCNT_inc_simple(av)); |
9850bf21 RH |
1672 | CX_CURPAD_SAVE(cx->blk_sub); |
1673 | cx->blk_sub.argarray = av; | |
1674 | } | |
1675 | ||
1676 | } | |
84d4ea48 | 1677 | } |
9850bf21 | 1678 | cx->cx_type |= CXp_MULTICALL; |
471178c0 NC |
1679 | |
1680 | start = p1 - max; | |
1681 | sortsvp(aTHX_ start, max, | |
7b9ef140 RH |
1682 | (is_xsub ? S_sortcv_xsub : hasargs ? S_sortcv_stacked : S_sortcv), |
1683 | sort_flags); | |
84d4ea48 | 1684 | |
9850bf21 RH |
1685 | if (!(flags & OPf_SPECIAL)) { |
1686 | LEAVESUB(cv); | |
1687 | if (!is_xsub) | |
1688 | CvDEPTH(cv)--; | |
1689 | } | |
84d4ea48 JH |
1690 | POPBLOCK(cx,PL_curpm); |
1691 | PL_stack_sp = newsp; | |
1692 | POPSTACK; | |
1693 | CATCH_SET(oldcatch); | |
1694 | } | |
fe1bc4cf | 1695 | else { |
84d4ea48 | 1696 | MEXTEND(SP, 20); /* Can't afford stack realloc on signal. */ |
471178c0 NC |
1697 | start = sorting_av ? AvARRAY(av) : ORIGMARK+1; |
1698 | sortsvp(aTHX_ start, max, | |
0723351e | 1699 | (priv & OPpSORT_NUMERIC) |
4d562308 | 1700 | ? ( ( ( priv & OPpSORT_INTEGER) || all_SIVs) |
f0f5dc9d AL |
1701 | ? ( overloading ? S_amagic_i_ncmp : S_sv_i_ncmp) |
1702 | : ( overloading ? S_amagic_ncmp : S_sv_ncmp ) ) | |
84d4ea48 JH |
1703 | : ( IN_LOCALE_RUNTIME |
1704 | ? ( overloading | |
d3fcec1f SP |
1705 | ? (SVCOMPARE_t)S_amagic_cmp_locale |
1706 | : (SVCOMPARE_t)sv_cmp_locale_static) | |
1707 | : ( overloading ? (SVCOMPARE_t)S_amagic_cmp : (SVCOMPARE_t)sv_cmp_static)), | |
7b9ef140 | 1708 | sort_flags); |
471178c0 | 1709 | } |
7b9ef140 | 1710 | if ((priv & OPpSORT_REVERSE) != 0) { |
471178c0 NC |
1711 | SV **q = start+max-1; |
1712 | while (start < q) { | |
0bcc34c2 | 1713 | SV * const tmp = *start; |
471178c0 NC |
1714 | *start++ = *q; |
1715 | *q-- = tmp; | |
84d4ea48 JH |
1716 | } |
1717 | } | |
1718 | } | |
9850bf21 RH |
1719 | if (sorting_av) |
1720 | SvREADONLY_off(av); | |
1721 | else if (av && !sorting_av) { | |
fe1bc4cf | 1722 | /* simulate pp_aassign of tied AV */ |
62b40d24 | 1723 | SV** const base = MARK+1; |
901017d6 AL |
1724 | for (i=0; i < max; i++) { |
1725 | base[i] = newSVsv(base[i]); | |
fe1bc4cf DM |
1726 | } |
1727 | av_clear(av); | |
1728 | av_extend(av, max); | |
1729 | for (i=0; i < max; i++) { | |
901017d6 | 1730 | SV * const sv = base[i]; |
551405c4 | 1731 | SV ** const didstore = av_store(av, i, sv); |
fe1bc4cf DM |
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 | ||
1743 | static I32 | |
31e9e0a3 | 1744 | S_sortcv(pTHX_ SV *const a, SV *const b) |
84d4ea48 | 1745 | { |
27da23d5 | 1746 | dVAR; |
901017d6 AL |
1747 | const I32 oldsaveix = PL_savestack_ix; |
1748 | const I32 oldscopeix = PL_scopestack_ix; | |
84d4ea48 | 1749 | I32 result; |
7918f24d NC |
1750 | |
1751 | PERL_ARGS_ASSERT_SORTCV; | |
1752 | ||
84d4ea48 JH |
1753 | GvSV(PL_firstgv) = a; |
1754 | GvSV(PL_secondgv) = b; | |
1755 | PL_stack_sp = PL_stack_base; | |
1756 | PL_op = PL_sortcop; | |
1757 | CALLRUNOPS(aTHX); | |
1758 | if (PL_stack_sp != PL_stack_base + 1) | |
1759 | Perl_croak(aTHX_ "Sort subroutine didn't return single value"); | |
1760 | if (!SvNIOKp(*PL_stack_sp)) | |
1761 | Perl_croak(aTHX_ "Sort subroutine didn't return a numeric value"); | |
1762 | result = SvIV(*PL_stack_sp); | |
1763 | while (PL_scopestack_ix > oldscopeix) { | |
1764 | LEAVE; | |
1765 | } | |
1766 | leave_scope(oldsaveix); | |
1767 | return result; | |
1768 | } | |
1769 | ||
1770 | static I32 | |
31e9e0a3 | 1771 | S_sortcv_stacked(pTHX_ SV *const a, SV *const b) |
84d4ea48 | 1772 | { |
27da23d5 | 1773 | dVAR; |
901017d6 AL |
1774 | const I32 oldsaveix = PL_savestack_ix; |
1775 | const I32 oldscopeix = PL_scopestack_ix; | |
84d4ea48 | 1776 | I32 result; |
901017d6 | 1777 | AV * const av = GvAV(PL_defgv); |
84d4ea48 | 1778 | |
7918f24d NC |
1779 | PERL_ARGS_ASSERT_SORTCV_STACKED; |
1780 | ||
84d4ea48 JH |
1781 | if (AvMAX(av) < 1) { |
1782 | SV** ary = AvALLOC(av); | |
1783 | if (AvARRAY(av) != ary) { | |
1784 | AvMAX(av) += AvARRAY(av) - AvALLOC(av); | |
9c6bc640 | 1785 | AvARRAY(av) = ary; |
84d4ea48 JH |
1786 | } |
1787 | if (AvMAX(av) < 1) { | |
1788 | AvMAX(av) = 1; | |
1789 | Renew(ary,2,SV*); | |
9c6bc640 | 1790 | AvARRAY(av) = ary; |
84d4ea48 JH |
1791 | } |
1792 | } | |
1793 | AvFILLp(av) = 1; | |
1794 | ||
1795 | AvARRAY(av)[0] = a; | |
1796 | AvARRAY(av)[1] = b; | |
1797 | PL_stack_sp = PL_stack_base; | |
1798 | PL_op = PL_sortcop; | |
1799 | CALLRUNOPS(aTHX); | |
1800 | if (PL_stack_sp != PL_stack_base + 1) | |
1801 | Perl_croak(aTHX_ "Sort subroutine didn't return single value"); | |
1802 | if (!SvNIOKp(*PL_stack_sp)) | |
1803 | Perl_croak(aTHX_ "Sort subroutine didn't return a numeric value"); | |
1804 | result = SvIV(*PL_stack_sp); | |
1805 | while (PL_scopestack_ix > oldscopeix) { | |
1806 | LEAVE; | |
1807 | } | |
1808 | leave_scope(oldsaveix); | |
1809 | return result; | |
1810 | } | |
1811 | ||
1812 | static I32 | |
31e9e0a3 | 1813 | S_sortcv_xsub(pTHX_ SV *const a, SV *const b) |
84d4ea48 | 1814 | { |
27da23d5 | 1815 | dVAR; dSP; |
901017d6 AL |
1816 | const I32 oldsaveix = PL_savestack_ix; |
1817 | const I32 oldscopeix = PL_scopestack_ix; | |
ea726b52 | 1818 | CV * const cv=MUTABLE_CV(PL_sortcop); |
84d4ea48 | 1819 | I32 result; |
84d4ea48 | 1820 | |
7918f24d NC |
1821 | PERL_ARGS_ASSERT_SORTCV_XSUB; |
1822 | ||
84d4ea48 JH |
1823 | SP = PL_stack_base; |
1824 | PUSHMARK(SP); | |
1825 | EXTEND(SP, 2); | |
1826 | *++SP = a; | |
1827 | *++SP = b; | |
1828 | PUTBACK; | |
1829 | (void)(*CvXSUB(cv))(aTHX_ cv); | |
1830 | if (PL_stack_sp != PL_stack_base + 1) | |
1831 | Perl_croak(aTHX_ "Sort subroutine didn't return single value"); | |
1832 | if (!SvNIOKp(*PL_stack_sp)) | |
1833 | Perl_croak(aTHX_ "Sort subroutine didn't return a numeric value"); | |
1834 | result = SvIV(*PL_stack_sp); | |
1835 | while (PL_scopestack_ix > oldscopeix) { | |
1836 | LEAVE; | |
1837 | } | |
1838 | leave_scope(oldsaveix); | |
1839 | return result; | |
1840 | } | |
1841 | ||
1842 | ||
1843 | static I32 | |
31e9e0a3 | 1844 | S_sv_ncmp(pTHX_ SV *const a, SV *const b) |
84d4ea48 | 1845 | { |
901017d6 AL |
1846 | const NV nv1 = SvNSIV(a); |
1847 | const NV nv2 = SvNSIV(b); | |
7918f24d NC |
1848 | |
1849 | PERL_ARGS_ASSERT_SV_NCMP; | |
1850 | ||
84d4ea48 JH |
1851 | return nv1 < nv2 ? -1 : nv1 > nv2 ? 1 : 0; |
1852 | } | |
1853 | ||
1854 | static I32 | |
31e9e0a3 | 1855 | S_sv_i_ncmp(pTHX_ SV *const a, SV *const b) |
84d4ea48 | 1856 | { |
901017d6 AL |
1857 | const IV iv1 = SvIV(a); |
1858 | const IV iv2 = SvIV(b); | |
7918f24d NC |
1859 | |
1860 | PERL_ARGS_ASSERT_SV_I_NCMP; | |
1861 | ||
84d4ea48 JH |
1862 | return iv1 < iv2 ? -1 : iv1 > iv2 ? 1 : 0; |
1863 | } | |
901017d6 AL |
1864 | |
1865 | #define tryCALL_AMAGICbin(left,right,meth) \ | |
1866 | (PL_amagic_generation && (SvAMAGIC(left)||SvAMAGIC(right))) \ | |
1867 | ? amagic_call(left, right, CAT2(meth,_amg), 0) \ | |
a0714e2c | 1868 | : NULL; |
84d4ea48 | 1869 | |
eeb9de02 TS |
1870 | #define SORT_NORMAL_RETURN_VALUE(val) (((val) > 0) ? 1 : ((val) ? -1 : 0)) |
1871 | ||
84d4ea48 | 1872 | static I32 |
31e9e0a3 | 1873 | S_amagic_ncmp(pTHX_ register SV *const a, register SV *const b) |
84d4ea48 | 1874 | { |
97aff369 | 1875 | dVAR; |
901017d6 | 1876 | SV * const tmpsv = tryCALL_AMAGICbin(a,b,ncmp); |
7918f24d NC |
1877 | |
1878 | PERL_ARGS_ASSERT_AMAGIC_NCMP; | |
1879 | ||
84d4ea48 | 1880 | if (tmpsv) { |
84d4ea48 | 1881 | if (SvIOK(tmpsv)) { |
901017d6 | 1882 | const I32 i = SvIVX(tmpsv); |
eeb9de02 | 1883 | return SORT_NORMAL_RETURN_VALUE(i); |
84d4ea48 | 1884 | } |
901017d6 AL |
1885 | else { |
1886 | const NV d = SvNV(tmpsv); | |
eeb9de02 | 1887 | return SORT_NORMAL_RETURN_VALUE(d); |
901017d6 | 1888 | } |
84d4ea48 | 1889 | } |
f0f5dc9d | 1890 | return S_sv_ncmp(aTHX_ a, b); |
84d4ea48 JH |
1891 | } |
1892 | ||
1893 | static I32 | |
31e9e0a3 | 1894 | S_amagic_i_ncmp(pTHX_ register SV *const a, register SV *const b) |
84d4ea48 | 1895 | { |
97aff369 | 1896 | dVAR; |
901017d6 | 1897 | SV * const tmpsv = tryCALL_AMAGICbin(a,b,ncmp); |
7918f24d NC |
1898 | |
1899 | PERL_ARGS_ASSERT_AMAGIC_I_NCMP; | |
1900 | ||
84d4ea48 | 1901 | if (tmpsv) { |
84d4ea48 | 1902 | if (SvIOK(tmpsv)) { |
901017d6 | 1903 | const I32 i = SvIVX(tmpsv); |
eeb9de02 | 1904 | return SORT_NORMAL_RETURN_VALUE(i); |
84d4ea48 | 1905 | } |
901017d6 AL |
1906 | else { |
1907 | const NV d = SvNV(tmpsv); | |
eeb9de02 | 1908 | return SORT_NORMAL_RETURN_VALUE(d); |
901017d6 | 1909 | } |
84d4ea48 | 1910 | } |
f0f5dc9d | 1911 | return S_sv_i_ncmp(aTHX_ a, b); |
84d4ea48 JH |
1912 | } |
1913 | ||
1914 | static I32 | |
31e9e0a3 | 1915 | S_amagic_cmp(pTHX_ register SV *const str1, register SV *const str2) |
84d4ea48 | 1916 | { |
97aff369 | 1917 | dVAR; |
901017d6 | 1918 | SV * const tmpsv = tryCALL_AMAGICbin(str1,str2,scmp); |
7918f24d NC |
1919 | |
1920 | PERL_ARGS_ASSERT_AMAGIC_CMP; | |
1921 | ||
84d4ea48 | 1922 | if (tmpsv) { |
84d4ea48 | 1923 | if (SvIOK(tmpsv)) { |
901017d6 | 1924 | const I32 i = SvIVX(tmpsv); |
eeb9de02 | 1925 | return SORT_NORMAL_RETURN_VALUE(i); |
84d4ea48 | 1926 | } |
901017d6 AL |
1927 | else { |
1928 | const NV d = SvNV(tmpsv); | |
eeb9de02 | 1929 | return SORT_NORMAL_RETURN_VALUE(d); |
901017d6 | 1930 | } |
84d4ea48 JH |
1931 | } |
1932 | return sv_cmp(str1, str2); | |
1933 | } | |
1934 | ||
1935 | static I32 | |
31e9e0a3 | 1936 | S_amagic_cmp_locale(pTHX_ register SV *const str1, register SV *const str2) |
84d4ea48 | 1937 | { |
97aff369 | 1938 | dVAR; |
901017d6 | 1939 | SV * const tmpsv = tryCALL_AMAGICbin(str1,str2,scmp); |
7918f24d NC |
1940 | |
1941 | PERL_ARGS_ASSERT_AMAGIC_CMP_LOCALE; | |
1942 | ||
84d4ea48 | 1943 | if (tmpsv) { |
84d4ea48 | 1944 | if (SvIOK(tmpsv)) { |
901017d6 | 1945 | const I32 i = SvIVX(tmpsv); |
eeb9de02 | 1946 | return SORT_NORMAL_RETURN_VALUE(i); |
84d4ea48 | 1947 | } |
901017d6 AL |
1948 | else { |
1949 | const NV d = SvNV(tmpsv); | |
eeb9de02 | 1950 | return SORT_NORMAL_RETURN_VALUE(d); |
901017d6 | 1951 | } |
84d4ea48 JH |
1952 | } |
1953 | return sv_cmp_locale(str1, str2); | |
1954 | } | |
241d1a3b NC |
1955 | |
1956 | /* | |
1957 | * Local variables: | |
1958 | * c-indentation-style: bsd | |
1959 | * c-basic-offset: 4 | |
1960 | * indent-tabs-mode: t | |
1961 | * End: | |
1962 | * | |
37442d52 RGS |
1963 | * ex: set ts=8 sts=4 sw=4 noet: |
1964 | */ |