Annotation of src/usr.bin/lex/tblcmp.c, Revision 1.8
1.8 ! tedu 1: /* $OpenBSD: tblcmp.c,v 1.7 2015/11/19 19:43:40 tedu Exp $ */
1.2 deraadt 2:
1.1 deraadt 3: /* tblcmp - table compression routines */
4:
1.7 tedu 5: /* Copyright (c) 1990 The Regents of the University of California. */
6: /* All rights reserved. */
7:
8: /* This code is derived from software contributed to Berkeley by */
9: /* Vern Paxson. */
1.1 deraadt 10:
1.7 tedu 11: /* The United States Government has rights in this work pursuant */
12: /* to contract no. DE-AC03-76SF00098 between the United States */
13: /* Department of Energy and the University of California. */
14:
15: /* This file is part of flex. */
16:
17: /* Redistribution and use in source and binary forms, with or without */
18: /* modification, are permitted provided that the following conditions */
19: /* are met: */
20:
21: /* 1. Redistributions of source code must retain the above copyright */
22: /* notice, this list of conditions and the following disclaimer. */
23: /* 2. Redistributions in binary form must reproduce the above copyright */
24: /* notice, this list of conditions and the following disclaimer in the */
25: /* documentation and/or other materials provided with the distribution. */
26:
27: /* Neither the name of the University nor the names of its contributors */
28: /* may be used to endorse or promote products derived from this software */
29: /* without specific prior written permission. */
30:
31: /* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
32: /* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
33: /* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
34: /* PURPOSE. */
1.1 deraadt 35:
36: #include "flexdef.h"
37:
38:
39: /* declarations for functions that have forward references */
40:
1.8 ! tedu 41: void mkentry PROTO((int *, int, int, int, int));
! 42: void mkprot PROTO((int[], int, int));
! 43: void mktemplate PROTO((int[], int, int));
! 44: void mv2front PROTO((int));
! 45: int tbldiff PROTO((int[], int, int[]));
1.1 deraadt 46:
47:
48: /* bldtbl - build table entries for dfa state
49: *
50: * synopsis
51: * int state[numecs], statenum, totaltrans, comstate, comfreq;
52: * bldtbl( state, statenum, totaltrans, comstate, comfreq );
53: *
54: * State is the statenum'th dfa state. It is indexed by equivalence class and
55: * gives the number of the state to enter for a given equivalence class.
56: * totaltrans is the total number of transitions out of the state. Comstate
57: * is that state which is the destination of the most transitions out of State.
58: * Comfreq is how many transitions there are out of State to Comstate.
59: *
60: * A note on terminology:
61: * "protos" are transition tables which have a high probability of
62: * either being redundant (a state processed later will have an identical
63: * transition table) or nearly redundant (a state processed later will have
64: * many of the same out-transitions). A "most recently used" queue of
65: * protos is kept around with the hope that most states will find a proto
66: * which is similar enough to be usable, and therefore compacting the
67: * output tables.
68: * "templates" are a special type of proto. If a transition table is
69: * homogeneous or nearly homogeneous (all transitions go to the same
70: * destination) then the odds are good that future states will also go
71: * to the same destination state on basically the same character set.
72: * These homogeneous states are so common when dealing with large rule
73: * sets that they merit special attention. If the transition table were
74: * simply made into a proto, then (typically) each subsequent, similar
75: * state will differ from the proto for two out-transitions. One of these
76: * out-transitions will be that character on which the proto does not go
77: * to the common destination, and one will be that character on which the
78: * state does not go to the common destination. Templates, on the other
79: * hand, go to the common state on EVERY transition character, and therefore
80: * cost only one difference.
81: */
82:
1.8 ! tedu 83: void
! 84: bldtbl(state, statenum, totaltrans, comstate, comfreq)
! 85: int state[], statenum, totaltrans, comstate, comfreq;
! 86: {
! 87: int extptr, extrct[2][CSIZE + 1];
! 88: int mindiff, minprot, i, d;
! 89:
! 90: /*
! 91: * If extptr is 0 then the first array of extrct holds the result of
! 92: * the "best difference" to date, which is those transitions which
! 93: * occur in "state" but not in the proto which, to date, has the
! 94: * fewest differences between itself and "state". If extptr is 1
! 95: * then the second array of extrct hold the best difference. The two
! 96: * arrays are toggled between so that the best difference to date can
! 97: * be kept around and also a difference just created by checking
! 98: * against a candidate "best" proto.
1.1 deraadt 99: */
100:
101: extptr = 0;
102:
1.8 ! tedu 103: /*
! 104: * If the state has too few out-transitions, don't bother trying to
1.1 deraadt 105: * compact its tables.
106: */
107:
1.7 tedu 108: if ((totaltrans * 100) < (numecs * PROTO_SIZE_PERCENTAGE))
1.8 ! tedu 109: mkentry(state, numecs, statenum, JAMSTATE, totaltrans);
1.1 deraadt 110:
1.7 tedu 111: else {
1.8 ! tedu 112: /*
! 113: * "checkcom" is true if we should only check "state" against
1.1 deraadt 114: * protos which have the same "comstate" value.
115: */
1.8 ! tedu 116: int checkcom =
1.7 tedu 117:
1.8 ! tedu 118: comfreq * 100 > totaltrans * CHECK_COM_PERCENTAGE;
1.1 deraadt 119:
120: minprot = firstprot;
121: mindiff = totaltrans;
122:
1.7 tedu 123: if (checkcom) {
1.1 deraadt 124: /* Find first proto which has the same "comstate". */
1.7 tedu 125: for (i = firstprot; i != NIL; i = protnext[i])
126: if (protcomst[i] == comstate) {
1.1 deraadt 127: minprot = i;
1.8 ! tedu 128: mindiff = tbldiff(state, minprot,
! 129: extrct[extptr]);
1.1 deraadt 130: break;
1.7 tedu 131: }
1.8 ! tedu 132: } else {
! 133: /*
! 134: * Since we've decided that the most common
! 135: * destination out of "state" does not occur with a
! 136: * high enough frequency, we set the "comstate" to
! 137: * zero, assuring that if this state is entered into
! 138: * the proto list, it will not be considered a
! 139: * template.
1.1 deraadt 140: */
141: comstate = 0;
142:
1.7 tedu 143: if (firstprot != NIL) {
1.1 deraadt 144: minprot = firstprot;
1.8 ! tedu 145: mindiff = tbldiff(state, minprot,
! 146: extrct[extptr]);
1.1 deraadt 147: }
1.7 tedu 148: }
1.1 deraadt 149:
1.8 ! tedu 150: /*
! 151: * We now have the first interesting proto in "minprot". If
1.1 deraadt 152: * it matches within the tolerances set for the first proto,
1.8 ! tedu 153: * we don't want to bother scanning the rest of the proto
! 154: * list to see if we have any other reasonable matches.
1.1 deraadt 155: */
156:
1.7 tedu 157: if (mindiff * 100 >
158: totaltrans * FIRST_MATCH_DIFF_PERCENTAGE) {
1.8 ! tedu 159: /*
! 160: * Not a good enough match. Scan the rest of the
1.1 deraadt 161: * protos.
162: */
1.7 tedu 163: for (i = minprot; i != NIL; i = protnext[i]) {
1.8 ! tedu 164: d = tbldiff(state, i, extrct[1 - extptr]);
1.7 tedu 165: if (d < mindiff) {
1.1 deraadt 166: extptr = 1 - extptr;
167: mindiff = d;
168: minprot = i;
169: }
170: }
1.7 tedu 171: }
1.8 ! tedu 172: /*
! 173: * Check if the proto we've decided on as our best bet is
! 174: * close enough to the state we want to match to be usable.
1.1 deraadt 175: */
176:
1.7 tedu 177: if (mindiff * 100 >
178: totaltrans * ACCEPTABLE_DIFF_PERCENTAGE) {
1.8 ! tedu 179: /*
! 180: * No good. If the state is homogeneous enough, we
! 181: * make a template out of it. Otherwise, we make a
! 182: * proto.
1.1 deraadt 183: */
184:
1.7 tedu 185: if (comfreq * 100 >=
186: totaltrans * TEMPLATE_SAME_PERCENTAGE)
1.8 ! tedu 187: mktemplate(state, statenum,
! 188: comstate);
1.1 deraadt 189:
1.7 tedu 190: else {
1.8 ! tedu 191: mkprot(state, statenum, comstate);
! 192: mkentry(state, numecs, statenum,
! 193: JAMSTATE, totaltrans);
1.1 deraadt 194: }
1.8 ! tedu 195: } else { /* use the proto */
! 196: mkentry(extrct[extptr], numecs, statenum,
! 197: prottbl[minprot], mindiff);
1.1 deraadt 198:
1.8 ! tedu 199: /*
! 200: * If this state was sufficiently different from the
1.1 deraadt 201: * proto we built it from, make it, too, a proto.
202: */
203:
1.7 tedu 204: if (mindiff * 100 >=
205: totaltrans * NEW_PROTO_DIFF_PERCENTAGE)
1.8 ! tedu 206: mkprot(state, statenum, comstate);
1.1 deraadt 207:
1.8 ! tedu 208: /*
! 209: * Since mkprot added a new proto to the proto queue,
1.1 deraadt 210: * it's possible that "minprot" is no longer on the
211: * proto queue (if it happened to have been the last
212: * entry, it would have been bumped off). If it's
213: * not there, then the new proto took its physical
214: * place (though logically the new proto is at the
215: * beginning of the queue), so in that case the
216: * following call will do nothing.
217: */
218:
1.8 ! tedu 219: mv2front(minprot);
1.1 deraadt 220: }
221: }
1.7 tedu 222: }
1.1 deraadt 223:
224:
225: /* cmptmps - compress template table entries
226: *
227: * Template tables are compressed by using the 'template equivalence
228: * classes', which are collections of transition character equivalence
229: * classes which always appear together in templates - really meta-equivalence
230: * classes.
231: */
232:
1.8 ! tedu 233: void
! 234: cmptmps()
1.7 tedu 235: {
1.8 ! tedu 236: int tmpstorage[CSIZE + 1];
1.5 mpech 237: int *tmp = tmpstorage, i, j;
1.8 ! tedu 238: int totaltrans, trans;
1.1 deraadt 239:
240: peakpairs = numtemps * numecs + tblend;
241:
1.7 tedu 242: if (usemecs) {
1.8 ! tedu 243: /*
! 244: * Create equivalence classes based on data gathered on
1.1 deraadt 245: * template transitions.
246: */
1.8 ! tedu 247: nummecs = cre8ecs(tecfwd, tecbck, numecs);
! 248: } else
1.1 deraadt 249: nummecs = numecs;
250:
1.7 tedu 251: while (lastdfa + numtemps + 1 >= current_max_dfas)
1.8 ! tedu 252: increase_max_dfas();
1.1 deraadt 253:
254: /* Loop through each template. */
255:
1.7 tedu 256: for (i = 1; i <= numtemps; ++i) {
1.1 deraadt 257: /* Number of non-jam transitions out of this template. */
258: totaltrans = 0;
259:
1.7 tedu 260: for (j = 1; j <= numecs; ++j) {
1.1 deraadt 261: trans = tnxt[numecs * i + j];
262:
1.7 tedu 263: if (usemecs) {
1.8 ! tedu 264: /*
! 265: * The absolute value of tecbck is the
1.1 deraadt 266: * meta-equivalence class of a given
267: * equivalence class, as set up by cre8ecs().
268: */
1.7 tedu 269: if (tecbck[j] > 0) {
1.1 deraadt 270: tmp[tecbck[j]] = trans;
271:
1.7 tedu 272: if (trans > 0)
1.1 deraadt 273: ++totaltrans;
274: }
1.8 ! tedu 275: } else {
1.1 deraadt 276: tmp[j] = trans;
277:
1.7 tedu 278: if (trans > 0)
1.1 deraadt 279: ++totaltrans;
280: }
1.7 tedu 281: }
1.1 deraadt 282:
1.8 ! tedu 283: /*
! 284: * It is assumed (in a rather subtle way) in the skeleton
1.1 deraadt 285: * that if we're using meta-equivalence classes, the def[]
286: * entry for all templates is the jam template, i.e.,
287: * templates never default to other non-jam table entries
288: * (e.g., another template)
289: */
290:
291: /* Leave room for the jam-state after the last real state. */
1.8 ! tedu 292: mkentry(tmp, nummecs, lastdfa + i + 1, JAMSTATE,
! 293: totaltrans);
1.1 deraadt 294: }
1.7 tedu 295: }
1.1 deraadt 296:
297:
298:
299: /* expand_nxt_chk - expand the next check arrays */
300:
1.8 ! tedu 301: void
! 302: expand_nxt_chk()
1.7 tedu 303: {
1.5 mpech 304: int old_max = current_max_xpairs;
1.1 deraadt 305:
306: current_max_xpairs += MAX_XPAIRS_INCREMENT;
307:
308: ++num_reallocs;
309:
1.8 ! tedu 310: nxt = reallocate_integer_array(nxt, current_max_xpairs);
! 311: chk = reallocate_integer_array(chk, current_max_xpairs);
1.1 deraadt 312:
1.8 ! tedu 313: zero_out((char *) (chk + old_max),
! 314: (size_t) (MAX_XPAIRS_INCREMENT * sizeof(int)));
1.7 tedu 315: }
1.1 deraadt 316:
317:
318: /* find_table_space - finds a space in the table for a state to be placed
319: *
320: * synopsis
321: * int *state, numtrans, block_start;
322: * int find_table_space();
323: *
324: * block_start = find_table_space( state, numtrans );
325: *
326: * State is the state to be added to the full speed transition table.
327: * Numtrans is the number of out-transitions for the state.
328: *
329: * find_table_space() returns the position of the start of the first block (in
330: * chk) able to accommodate the state
331: *
332: * In determining if a state will or will not fit, find_table_space() must take
333: * into account the fact that an end-of-buffer state will be added at [0],
334: * and an action number will be added in [-1].
335: */
336:
1.8 ! tedu 337: int
! 338: find_table_space(state, numtrans)
! 339: int *state, numtrans;
1.7 tedu 340: {
1.8 ! tedu 341: /*
! 342: * Firstfree is the position of the first possible occurrence of two
1.1 deraadt 343: * consecutive unused records in the chk and nxt arrays.
344: */
1.5 mpech 345: int i;
346: int *state_ptr, *chk_ptr;
347: int *ptr_to_last_entry_in_state;
1.1 deraadt 348:
1.8 ! tedu 349: /*
! 350: * If there are too many out-transitions, put the state at the end of
1.1 deraadt 351: * nxt and chk.
352: */
1.7 tedu 353: if (numtrans > MAX_XTIONS_FULL_INTERIOR_FIT) {
1.8 ! tedu 354: /*
! 355: * If table is empty, return the first available spot in
1.1 deraadt 356: * chk/nxt, which should be 1.
357: */
1.7 tedu 358: if (tblend < 2)
1.1 deraadt 359: return 1;
360:
1.8 ! tedu 361: /*
! 362: * Start searching for table space near the end of chk/nxt
! 363: * arrays.
1.1 deraadt 364: */
365: i = tblend - numecs;
1.8 ! tedu 366: } else
! 367: /*
! 368: * Start searching for table space from the beginning
! 369: * (skipping only the elements which will definitely not hold
! 370: * the new state).
1.1 deraadt 371: */
372: i = firstfree;
373:
1.7 tedu 374: while (1) { /* loops until a space is found */
375: while (i + numecs >= current_max_xpairs)
1.8 ! tedu 376: expand_nxt_chk();
1.1 deraadt 377:
1.8 ! tedu 378: /*
! 379: * Loops until space for end-of-buffer and action number are
! 380: * found.
1.1 deraadt 381: */
1.7 tedu 382: while (1) {
1.1 deraadt 383: /* Check for action number space. */
1.7 tedu 384: if (chk[i - 1] == 0) {
1.1 deraadt 385: /* Check for end-of-buffer space. */
1.7 tedu 386: if (chk[i] == 0)
1.1 deraadt 387: break;
388:
389: else
1.8 ! tedu 390: /*
! 391: * Since i != 0, there is no use
1.1 deraadt 392: * checking to see if (++i) - 1 == 0,
393: * because that's the same as i == 0,
394: * so we skip a space.
395: */
396: i += 2;
1.8 ! tedu 397: } else
1.1 deraadt 398: ++i;
399:
1.7 tedu 400: while (i + numecs >= current_max_xpairs)
1.8 ! tedu 401: expand_nxt_chk();
1.7 tedu 402: }
1.1 deraadt 403:
1.8 ! tedu 404: /*
! 405: * If we started search from the beginning, store the new
1.1 deraadt 406: * firstfree for the next call of find_table_space().
407: */
1.7 tedu 408: if (numtrans <= MAX_XTIONS_FULL_INTERIOR_FIT)
1.1 deraadt 409: firstfree = i + 1;
410:
1.8 ! tedu 411: /*
! 412: * Check to see if all elements in chk (and therefore nxt)
1.1 deraadt 413: * that are needed for the new state have not yet been taken.
414: */
415:
416: state_ptr = &state[1];
417: ptr_to_last_entry_in_state = &chk[i + numecs + 1];
418:
1.7 tedu 419: for (chk_ptr = &chk[i + 1];
1.8 ! tedu 420: chk_ptr != ptr_to_last_entry_in_state; ++chk_ptr)
1.7 tedu 421: if (*(state_ptr++) != 0 && *chk_ptr != 0)
1.1 deraadt 422: break;
423:
1.7 tedu 424: if (chk_ptr == ptr_to_last_entry_in_state)
1.1 deraadt 425: return i;
426:
427: else
1.7 tedu 428: ++i;
1.1 deraadt 429: }
1.7 tedu 430: }
1.1 deraadt 431:
432:
433: /* inittbl - initialize transition tables
434: *
435: * Initializes "firstfree" to be one beyond the end of the table. Initializes
436: * all "chk" entries to be zero.
437: */
1.8 ! tedu 438: void
! 439: inittbl()
1.7 tedu 440: {
1.5 mpech 441: int i;
1.1 deraadt 442:
1.8 ! tedu 443: zero_out((char *) chk,
1.7 tedu 444:
1.8 ! tedu 445: (size_t) (current_max_xpairs * sizeof(int)));
1.1 deraadt 446:
447: tblend = 0;
448: firstfree = tblend + 1;
449: numtemps = 0;
450:
1.7 tedu 451: if (usemecs) {
1.8 ! tedu 452: /*
! 453: * Set up doubly-linked meta-equivalence classes; these are
! 454: * sets of equivalence classes which all have identical
1.1 deraadt 455: * transitions out of TEMPLATES.
456: */
457:
458: tecbck[1] = NIL;
459:
1.7 tedu 460: for (i = 2; i <= numecs; ++i) {
1.1 deraadt 461: tecbck[i] = i - 1;
462: tecfwd[i - 1] = i;
1.7 tedu 463: }
1.1 deraadt 464:
465: tecfwd[numecs] = NIL;
466: }
1.7 tedu 467: }
1.1 deraadt 468:
469:
470: /* mkdeftbl - make the default, "jam" table entries */
471:
1.8 ! tedu 472: void
! 473: mkdeftbl()
1.7 tedu 474: {
1.8 ! tedu 475: int i;
1.1 deraadt 476:
477: jamstate = lastdfa + 1;
478:
1.8 ! tedu 479: ++tblend; /* room for transition on end-of-buffer
! 480: * character */
1.1 deraadt 481:
1.7 tedu 482: while (tblend + numecs >= current_max_xpairs)
1.8 ! tedu 483: expand_nxt_chk();
1.1 deraadt 484:
485: /* Add in default end-of-buffer transition. */
486: nxt[tblend] = end_of_buffer_state;
487: chk[tblend] = jamstate;
488:
1.7 tedu 489: for (i = 1; i <= numecs; ++i) {
1.1 deraadt 490: nxt[tblend + i] = 0;
491: chk[tblend + i] = jamstate;
1.7 tedu 492: }
1.1 deraadt 493:
494: jambase = tblend;
495:
496: base[jamstate] = jambase;
497: def[jamstate] = 0;
498:
499: tblend += numecs;
500: ++numtemps;
1.7 tedu 501: }
1.1 deraadt 502:
503:
504: /* mkentry - create base/def and nxt/chk entries for transition array
505: *
506: * synopsis
507: * int state[numchars + 1], numchars, statenum, deflink, totaltrans;
508: * mkentry( state, numchars, statenum, deflink, totaltrans );
509: *
510: * "state" is a transition array "numchars" characters in size, "statenum"
511: * is the offset to be used into the base/def tables, and "deflink" is the
512: * entry to put in the "def" table entry. If "deflink" is equal to
513: * "JAMSTATE", then no attempt will be made to fit zero entries of "state"
514: * (i.e., jam entries) into the table. It is assumed that by linking to
515: * "JAMSTATE" they will be taken care of. In any case, entries in "state"
516: * marking transitions to "SAME_TRANS" are treated as though they will be
517: * taken care of by whereever "deflink" points. "totaltrans" is the total
518: * number of transitions out of the state. If it is below a certain threshold,
519: * the tables are searched for an interior spot that will accommodate the
520: * state array.
521: */
522:
1.8 ! tedu 523: void
! 524: mkentry(state, numchars, statenum, deflink, totaltrans)
! 525: int *state;
! 526: int numchars, statenum, deflink, totaltrans;
1.7 tedu 527: {
1.5 mpech 528: int minec, maxec, i, baseaddr;
1.8 ! tedu 529: int tblbase, tbllast;
1.1 deraadt 530:
1.7 tedu 531: if (totaltrans == 0) { /* there are no out-transitions */
532: if (deflink == JAMSTATE)
1.1 deraadt 533: base[statenum] = JAMSTATE;
534: else
535: base[statenum] = 0;
536:
537: def[statenum] = deflink;
538: return;
1.7 tedu 539: }
540: for (minec = 1; minec <= numchars; ++minec) {
541: if (state[minec] != SAME_TRANS)
542: if (state[minec] != 0 || deflink != JAMSTATE)
1.1 deraadt 543: break;
1.7 tedu 544: }
1.1 deraadt 545:
1.7 tedu 546: if (totaltrans == 1) {
1.8 ! tedu 547: /*
! 548: * There's only one out-transition. Save it for later to
! 549: * fill in holes in the tables.
1.1 deraadt 550: */
1.8 ! tedu 551: stack1(statenum, minec, state[minec], deflink);
1.1 deraadt 552: return;
1.7 tedu 553: }
554: for (maxec = numchars; maxec > 0; --maxec) {
555: if (state[maxec] != SAME_TRANS)
556: if (state[maxec] != 0 || deflink != JAMSTATE)
1.1 deraadt 557: break;
1.7 tedu 558: }
1.1 deraadt 559:
1.8 ! tedu 560: /*
! 561: * Whether we try to fit the state table in the middle of the table
1.1 deraadt 562: * entries we have already generated, or if we just take the state
563: * table at the end of the nxt/chk tables, we must make sure that we
564: * have a valid base address (i.e., non-negative). Note that
565: * negative base addresses dangerous at run-time (because indexing
566: * the nxt array with one and a low-valued character will access
567: * memory before the start of the array.
568: */
569:
570: /* Find the first transition of state that we need to worry about. */
1.7 tedu 571: if (totaltrans * 100 <= numchars * INTERIOR_FIT_PERCENTAGE) {
1.1 deraadt 572: /* Attempt to squeeze it into the middle of the tables. */
573: baseaddr = firstfree;
574:
1.7 tedu 575: while (baseaddr < minec) {
1.8 ! tedu 576: /*
! 577: * Using baseaddr would result in a negative base
1.1 deraadt 578: * address below; find the next free slot.
579: */
1.8 ! tedu 580: for (++baseaddr; chk[baseaddr] != 0; ++baseaddr);
1.7 tedu 581: }
1.1 deraadt 582:
1.7 tedu 583: while (baseaddr + maxec - minec + 1 >= current_max_xpairs)
1.8 ! tedu 584: expand_nxt_chk();
1.1 deraadt 585:
1.7 tedu 586: for (i = minec; i <= maxec; ++i)
587: if (state[i] != SAME_TRANS &&
588: (state[i] != 0 || deflink != JAMSTATE) &&
1.8 ! tedu 589: chk[baseaddr + i - minec] != 0) { /* baseaddr unsuitable -
! 590: * find another */
1.7 tedu 591: for (++baseaddr;
1.8 ! tedu 592: baseaddr < current_max_xpairs &&
! 593: chk[baseaddr] != 0; ++baseaddr);
1.7 tedu 594:
595: while (baseaddr + maxec - minec + 1 >=
1.8 ! tedu 596: current_max_xpairs)
! 597: expand_nxt_chk();
1.1 deraadt 598:
1.8 ! tedu 599: /*
! 600: * Reset the loop counter so we'll start all
1.1 deraadt 601: * over again next time it's incremented.
602: */
603:
604: i = minec - 1;
1.7 tedu 605: }
1.8 ! tedu 606: } else {
! 607: /*
! 608: * Ensure that the base address we eventually generate is
1.1 deraadt 609: * non-negative.
610: */
1.8 ! tedu 611: baseaddr = MAX(tblend + 1, minec);
1.7 tedu 612: }
1.1 deraadt 613:
614: tblbase = baseaddr - minec;
615: tbllast = tblbase + maxec;
616:
1.7 tedu 617: while (tbllast + 1 >= current_max_xpairs)
1.8 ! tedu 618: expand_nxt_chk();
1.1 deraadt 619:
620: base[statenum] = tblbase;
621: def[statenum] = deflink;
622:
1.7 tedu 623: for (i = minec; i <= maxec; ++i)
624: if (state[i] != SAME_TRANS)
625: if (state[i] != 0 || deflink != JAMSTATE) {
1.1 deraadt 626: nxt[tblbase + i] = state[i];
627: chk[tblbase + i] = statenum;
1.7 tedu 628: }
629: if (baseaddr == firstfree)
1.1 deraadt 630: /* Find next free slot in tables. */
1.8 ! tedu 631: for (++firstfree; chk[firstfree] != 0; ++firstfree);
1.1 deraadt 632:
1.8 ! tedu 633: tblend = MAX(tblend, tbllast);
1.7 tedu 634: }
1.1 deraadt 635:
636:
637: /* mk1tbl - create table entries for a state (or state fragment) which
638: * has only one out-transition
639: */
640:
1.8 ! tedu 641: void
! 642: mk1tbl(state, sym, onenxt, onedef)
! 643: int state, sym, onenxt, onedef;
1.7 tedu 644: {
645: if (firstfree < sym)
1.1 deraadt 646: firstfree = sym;
647:
1.7 tedu 648: while (chk[firstfree] != 0)
649: if (++firstfree >= current_max_xpairs)
1.8 ! tedu 650: expand_nxt_chk();
1.1 deraadt 651:
652: base[state] = firstfree - sym;
653: def[state] = onedef;
654: chk[firstfree] = state;
655: nxt[firstfree] = onenxt;
656:
1.7 tedu 657: if (firstfree > tblend) {
1.1 deraadt 658: tblend = firstfree++;
659:
1.7 tedu 660: if (firstfree >= current_max_xpairs)
1.8 ! tedu 661: expand_nxt_chk();
1.1 deraadt 662: }
1.7 tedu 663: }
1.1 deraadt 664:
665:
666: /* mkprot - create new proto entry */
667:
1.8 ! tedu 668: void
! 669: mkprot(state, statenum, comstate)
! 670: int state[], statenum, comstate;
1.7 tedu 671: {
1.8 ! tedu 672: int i, slot, tblbase;
1.1 deraadt 673:
1.7 tedu 674: if (++numprots >= MSP || numecs * numprots >= PROT_SAVE_SIZE) {
1.8 ! tedu 675: /*
! 676: * Gotta make room for the new proto by dropping last entry
! 677: * in the queue.
1.1 deraadt 678: */
679: slot = lastprot;
680: lastprot = protprev[lastprot];
681: protnext[lastprot] = NIL;
1.8 ! tedu 682: } else
1.1 deraadt 683: slot = numprots;
684:
685: protnext[slot] = firstprot;
686:
1.7 tedu 687: if (firstprot != NIL)
1.1 deraadt 688: protprev[firstprot] = slot;
689:
690: firstprot = slot;
691: prottbl[slot] = statenum;
692: protcomst[slot] = comstate;
693:
694: /* Copy state into save area so it can be compared with rapidly. */
695: tblbase = numecs * (slot - 1);
696:
1.7 tedu 697: for (i = 1; i <= numecs; ++i)
1.1 deraadt 698: protsave[tblbase + i] = state[i];
1.7 tedu 699: }
1.1 deraadt 700:
701:
702: /* mktemplate - create a template entry based on a state, and connect the state
703: * to it
704: */
705:
1.8 ! tedu 706: void
! 707: mktemplate(state, statenum, comstate)
! 708: int state[], statenum, comstate;
! 709: {
! 710: int i, numdiff, tmpbase, tmp[CSIZE + 1];
! 711: Char transset[CSIZE + 1];
! 712: int tsptr;
1.1 deraadt 713:
714: ++numtemps;
715:
716: tsptr = 0;
717:
1.8 ! tedu 718: /*
! 719: * Calculate where we will temporarily store the transition table of
! 720: * the template in the tnxt[] array. The final transition table gets
! 721: * created by cmptmps().
1.1 deraadt 722: */
723:
724: tmpbase = numtemps * numecs;
725:
1.7 tedu 726: if (tmpbase + numecs >= current_max_template_xpairs) {
727: current_max_template_xpairs +=
1.8 ! tedu 728: MAX_TEMPLATE_XPAIRS_INCREMENT;
1.1 deraadt 729:
730: ++num_reallocs;
731:
1.8 ! tedu 732: tnxt = reallocate_integer_array(tnxt,
! 733: current_max_template_xpairs);
1.7 tedu 734: }
735: for (i = 1; i <= numecs; ++i)
736: if (state[i] == 0)
1.1 deraadt 737: tnxt[tmpbase + i] = 0;
1.7 tedu 738: else {
1.1 deraadt 739: transset[tsptr++] = i;
740: tnxt[tmpbase + i] = comstate;
1.7 tedu 741: }
1.1 deraadt 742:
1.7 tedu 743: if (usemecs)
1.8 ! tedu 744: mkeccl(transset, tsptr, tecfwd, tecbck, numecs, 0);
1.1 deraadt 745:
1.8 ! tedu 746: mkprot(tnxt + tmpbase, -numtemps, comstate);
1.1 deraadt 747:
1.8 ! tedu 748: /*
! 749: * We rely on the fact that mkprot adds things to the beginning of
! 750: * the proto queue.
1.1 deraadt 751: */
752:
1.8 ! tedu 753: numdiff = tbldiff(state, firstprot, tmp);
! 754: mkentry(tmp, numecs, statenum, -numtemps, numdiff);
1.7 tedu 755: }
1.1 deraadt 756:
757:
758: /* mv2front - move proto queue element to front of queue */
759:
1.8 ! tedu 760: void
! 761: mv2front(qelm)
! 762: int qelm;
1.7 tedu 763: {
764: if (firstprot != qelm) {
765: if (qelm == lastprot)
1.1 deraadt 766: lastprot = protprev[lastprot];
767:
768: protnext[protprev[qelm]] = protnext[qelm];
769:
1.7 tedu 770: if (protnext[qelm] != NIL)
1.1 deraadt 771: protprev[protnext[qelm]] = protprev[qelm];
772:
773: protprev[qelm] = NIL;
774: protnext[qelm] = firstprot;
775: protprev[firstprot] = qelm;
776: firstprot = qelm;
777: }
1.7 tedu 778: }
1.1 deraadt 779:
780:
781: /* place_state - place a state into full speed transition table
782: *
783: * State is the statenum'th state. It is indexed by equivalence class and
784: * gives the number of the state to enter for a given equivalence class.
785: * Transnum is the number of out-transitions for the state.
786: */
787:
1.8 ! tedu 788: void
! 789: place_state(state, statenum, transnum)
! 790: int *state, statenum, transnum;
1.7 tedu 791: {
1.5 mpech 792: int i;
793: int *state_ptr;
1.8 ! tedu 794: int position = find_table_space(state, transnum);
1.1 deraadt 795:
796: /* "base" is the table of start positions. */
797: base[statenum] = position;
798:
1.8 ! tedu 799: /*
! 800: * Put in action number marker; this non-zero number makes sure that
1.1 deraadt 801: * find_table_space() knows that this position in chk/nxt is taken
802: * and should not be used for another accepting number in another
803: * state.
804: */
805: chk[position - 1] = 1;
806:
1.8 ! tedu 807: /*
! 808: * Put in end-of-buffer marker; this is for the same purposes as
1.1 deraadt 809: * above.
810: */
811: chk[position] = 1;
812:
813: /* Place the state into chk and nxt. */
814: state_ptr = &state[1];
815:
1.7 tedu 816: for (i = 1; i <= numecs; ++i, ++state_ptr)
817: if (*state_ptr != 0) {
1.1 deraadt 818: chk[position + i] = i;
819: nxt[position + i] = *state_ptr;
1.7 tedu 820: }
821: if (position + numecs > tblend)
1.1 deraadt 822: tblend = position + numecs;
1.7 tedu 823: }
1.1 deraadt 824:
825:
826: /* stack1 - save states with only one out-transition to be processed later
827: *
828: * If there's room for another state on the "one-transition" stack, the
829: * state is pushed onto it, to be processed later by mk1tbl. If there's
830: * no room, we process the sucker right now.
831: */
832:
1.8 ! tedu 833: void
! 834: stack1(statenum, sym, nextstate, deflink)
! 835: int statenum, sym, nextstate, deflink;
1.7 tedu 836: {
837: if (onesp >= ONE_STACK_SIZE - 1)
1.8 ! tedu 838: mk1tbl(statenum, sym, nextstate, deflink);
1.1 deraadt 839:
1.7 tedu 840: else {
1.1 deraadt 841: ++onesp;
842: onestate[onesp] = statenum;
843: onesym[onesp] = sym;
844: onenext[onesp] = nextstate;
845: onedef[onesp] = deflink;
846: }
1.7 tedu 847: }
1.1 deraadt 848:
849:
850: /* tbldiff - compute differences between two state tables
851: *
852: * "state" is the state array which is to be extracted from the pr'th
853: * proto. "pr" is both the number of the proto we are extracting from
854: * and an index into the save area where we can find the proto's complete
855: * state table. Each entry in "state" which differs from the corresponding
856: * entry of "pr" will appear in "ext".
857: *
858: * Entries which are the same in both "state" and "pr" will be marked
859: * as transitions to "SAME_TRANS" in "ext". The total number of differences
860: * between "state" and "pr" is returned as function value. Note that this
861: * number is "numecs" minus the number of "SAME_TRANS" entries in "ext".
862: */
863:
1.8 ! tedu 864: int
! 865: tbldiff(state, pr, ext)
! 866: int state[], pr, ext[];
1.7 tedu 867: {
1.5 mpech 868: int i, *sp = state, *ep = ext, *protp;
869: int numdiff = 0;
1.1 deraadt 870:
871: protp = &protsave[numecs * (pr - 1)];
872:
1.7 tedu 873: for (i = numecs; i > 0; --i) {
874: if (*++protp == *++sp)
1.1 deraadt 875: *++ep = SAME_TRANS;
1.7 tedu 876: else {
1.1 deraadt 877: *++ep = *sp;
878: ++numdiff;
879: }
1.7 tedu 880: }
1.1 deraadt 881:
882: return numdiff;
1.7 tedu 883: }
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