2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief double ended queue of generic pointers.
23 * @author Christian von Roques
24 * @date 1999 by getting from fiasco
44 /* Pointer Double Ended Queue */
45 #define PDEQ_MAGIC1 FOURCC('P','D','E','1')
46 #define PDEQ_MAGIC2 FOURCC('P','D','E','2')
48 /** Size of pdeq block cache. */
49 #define TUNE_NSAVED_PDEQS 16
52 * Maximal number of data items in a pdeq chunk.
54 #define NDATA ((int)((PREF_MALLOC_SIZE - offsetof (pdeq, data)) / sizeof (void *)))
57 # define VRFY(dq) ((void)0)
59 # define VRFY(dq) assert((dq) && ((dq)->magic == PDEQ_MAGIC1))
63 * A pointer double ended queue.
64 * This structure is used as a list chunk either.
68 unsigned magic; /**< debug magic */
70 pdeq *l_end, *r_end; /**< left and right ends of the queue */
71 pdeq *l, *r; /**< left and right neighbor */
72 int n; /**< number of elements in the current chunk */
73 int p; /**< the read/write pointer */
74 const void *data[1]; /**< storage for elements */
79 * cache of unused, pdeq blocks to speed up new_pdeq and del_pdeq.
80 * +1 for compilers that can't grok empty arrays
82 static pdeq *pdeq_block_cache[TUNE_NSAVED_PDEQS+1];
85 * Number of pdeqs in pdeq_store.
87 static unsigned pdeqs_cached;
90 * Free a pdeq chunk, put in into the cache if possible.
92 * @param p The pdeq chunk.
94 static inline void free_pdeq_block (pdeq *p)
97 p->magic = 0xbadf00d1;
99 if (pdeqs_cached < TUNE_NSAVED_PDEQS) {
100 pdeq_block_cache[pdeqs_cached++] = p;
107 * Allocate a new pdeq chunk, get it from the cache if possible.
109 * @return A new pdeq chunk.
111 static inline pdeq *alloc_pdeq_block (void)
114 if (TUNE_NSAVED_PDEQS && pdeqs_cached) {
115 p = pdeq_block_cache[--pdeqs_cached];
117 p = xmalloc(PREF_MALLOC_SIZE);
125 * Verify a double ended list, assert if failure.
127 * @param dq The list to verify.
129 void _pdeq_vrfy(pdeq *dq)
134 && (dq->magic == PDEQ_MAGIC1)
135 && (dq->l_end && dq->r_end));
138 assert ( ((q == dq) || (q->magic == PDEQ_MAGIC2))
139 && ((q == dq->l_end) ^ (q->l != NULL))
140 && ((q == dq->r_end) ^ (q->r != NULL))
141 && (!q->l || (q == q->l->r))
142 && ((q->n >= 0) && (q->n <= NDATA))
143 && ((q == dq->l_end) || (q == dq->r_end) || (q->n == NDATA))
144 && ((q->p >= 0) && (q->p < NDATA)));
150 /* Creates a new double ended pointer list. */
155 dq = alloc_pdeq_block();
158 dq->magic = PDEQ_MAGIC1;
160 dq->l_end = dq->r_end = dq;
161 dq->l = dq->r = NULL;
168 /* Creates a new double ended pointer list and puts an initial pointer element in. */
169 pdeq *new_pdeq1(const void *x)
171 return pdeq_putr(new_pdeq(), x);
174 /* Delete a double ended pointer list. */
175 void del_pdeq(pdeq *dq)
181 q = dq->l_end; /* left end of chain */
182 /* pdeq trunk empty, but !pdeq_empty() ==> trunk not in chain */
183 if (dq->n == 0 && dq->l_end != dq ) {
187 /* Free all blocks in the pdeq chain */
195 /* Checks if a list is empty. */
196 int pdeq_empty(pdeq *dq)
199 return dq->l_end->n == 0;
202 /* Returns the length of a double ended pointer list. */
203 int pdeq_len(pdeq *dq)
220 /* Add a pointer to the right site of a double ended pointer list. */
221 pdeq *pdeq_putr(pdeq *dq, const void *x)
229 if (rdq->n >= NDATA) { /* tailblock full */
232 ndq = dq; /* try to reuse trunk, but ... */
233 if (dq->n) { /* ... if trunk used */
234 /* allocate and init new block */
235 ndq = alloc_pdeq_block();
237 ndq->magic = PDEQ_MAGIC2;
239 ndq->l_end = ndq->r_end = NULL;
243 ndq->l = rdq; rdq->r = ndq;
244 ndq->n = 0; ndq->p = 0;
249 n = rdq->n++ + rdq->p;
250 if (n >= NDATA) n -= NDATA;
258 /* Add a pointer to the left site of a double ended pointer list. */
259 pdeq *pdeq_putl(pdeq *dq, const void *x)
267 if (ldq->n >= NDATA) { /* headblock full */
270 ndq = dq; /* try to reuse trunk, but ... */
271 if (dq->n) { /* ... if trunk used */
272 /* allocate and init new block */
273 ndq = alloc_pdeq_block();
275 ndq->magic = PDEQ_MAGIC2;
277 ndq->l_end = ndq->r_end = NULL;
281 ndq->r = ldq; ldq->l = ndq;
282 ndq->n = 0; ndq->p = 0;
289 if (p < 0) p += NDATA;
298 /* Retrieve a pointer from the right site of a double ended pointer list. */
299 void *pdeq_getr(pdeq *dq)
306 assert(dq->l_end->n);
309 n = rdq->p + --rdq->n;
310 if (n >= NDATA) n -= NDATA;
319 dq->r_end = dq->l_end = dq;
322 free_pdeq_block(rdq);
330 /* Retrieve a pointer from the left site of a double ended pointer list. */
331 void *pdeq_getl(pdeq *dq)
338 assert(dq->l_end->n);
343 if (++p >= NDATA) p = 0;
352 dq->l_end = dq->r_end = dq;
355 free_pdeq_block(ldq);
364 * Returns non-zero if a double ended pointer list
365 * contains a pointer x.
367 int pdeq_contains(pdeq *dq, const void *x)
377 p = q->p; ep = p + q->n;
381 if (q->data[p] == x) return 1;
382 } while (++p < NDATA);
388 if (q->data[p++] == x) return 1;
398 * Search a key in a double ended pointer list, the search
399 * is controlled by a compare function.
400 * An element is found, if the compare function returns 0.
401 * The search is started from the left site of the list.
403 void *pdeq_search(pdeq *dq, cmp_fun cmp, const void *key)
414 p = q->p; ep = p + q->n;
418 if (!cmp (q->data[p], key)) return (void *)q->data[p-1];
419 } while (++p < NDATA);
425 if (!cmp (q->data[p++], key)) return (void *)q->data[p-1];
435 * Convert the double ended pointer list into a linear array beginning from
436 * left, the first element in the linear array will be the left one.
438 void **pdeq_copyl(pdeq *dq, const void **dst)
441 const void **d = dst;
453 memcpy((void *) d, &q->data[p], nn * sizeof(void *)); d += nn;
457 memcpy((void *) d, &q->data[p], n * sizeof(void *)); d += n;
466 * Convert the double ended pointer list into a linear array beginning from
467 * right, the first element in the linear array will be the right one.
469 void **pdeq_copyr(pdeq *dq, const void **dst)
472 const void **d = dst;
480 p = q->p; i = q->n + p - 1;
483 do *d++ = q->data[i]; while (--i >= 0);
487 do *d++ = q->data[i]; while (--i >= p);