summaryrefslogtreecommitdiff
path: root/tblcmp.c
blob: a56aaabce1794ab2ccf4ceb55695ffbc5a6a6d06 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
/* tblcmp - table compression routines */

/*  Copyright (c) 1990 The Regents of the University of California. */
/*  All rights reserved. */

/*  This code is derived from software contributed to Berkeley by */
/*  Vern Paxson. */

/*  The United States Government has rights in this work pursuant */
/*  to contract no. DE-AC03-76SF00098 between the United States */
/*  Department of Energy and the University of California. */

/*  This file is part of flex. */

/*  Redistribution and use in source and binary forms, with or without */
/*  modification, are permitted provided that the following conditions */
/*  are met: */

/*  1. Redistributions of source code must retain the above copyright */
/*     notice, this list of conditions and the following disclaimer. */
/*  2. Redistributions in binary form must reproduce the above copyright */
/*     notice, this list of conditions and the following disclaimer in the */
/*     documentation and/or other materials provided with the distribution. */

/*  Neither the name of the University nor the names of its contributors */
/*  may be used to endorse or promote products derived from this software */
/*  without specific prior written permission. */

/*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
/*  IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
/*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
/*  PURPOSE. */

#include "flexdef.h"


/* declarations for functions that have forward references */

void mkentry PROTO ((register int *, int, int, int, int));
void mkprot PROTO ((int[], int, int));
void mktemplate PROTO ((int[], int, int));
void mv2front PROTO ((int));
int tbldiff PROTO ((int[], int, int[]));


/* bldtbl - build table entries for dfa state
 *
 * synopsis
 *   int state[numecs], statenum, totaltrans, comstate, comfreq;
 *   bldtbl( state, statenum, totaltrans, comstate, comfreq );
 *
 * State is the statenum'th dfa state.  It is indexed by equivalence class and
 * gives the number of the state to enter for a given equivalence class.
 * totaltrans is the total number of transitions out of the state.  Comstate
 * is that state which is the destination of the most transitions out of State.
 * Comfreq is how many transitions there are out of State to Comstate.
 *
 * A note on terminology:
 *    "protos" are transition tables which have a high probability of
 * either being redundant (a state processed later will have an identical
 * transition table) or nearly redundant (a state processed later will have
 * many of the same out-transitions).  A "most recently used" queue of
 * protos is kept around with the hope that most states will find a proto
 * which is similar enough to be usable, and therefore compacting the
 * output tables.
 *    "templates" are a special type of proto.  If a transition table is
 * homogeneous or nearly homogeneous (all transitions go to the same
 * destination) then the odds are good that future states will also go
 * to the same destination state on basically the same character set.
 * These homogeneous states are so common when dealing with large rule
 * sets that they merit special attention.  If the transition table were
 * simply made into a proto, then (typically) each subsequent, similar
 * state will differ from the proto for two out-transitions.  One of these
 * out-transitions will be that character on which the proto does not go
 * to the common destination, and one will be that character on which the
 * state does not go to the common destination.  Templates, on the other
 * hand, go to the common state on EVERY transition character, and therefore
 * cost only one difference.
 */

void    bldtbl (state, statenum, totaltrans, comstate, comfreq)
     int     state[], statenum, totaltrans, comstate, comfreq;
{
	int     extptr, extrct[2][CSIZE + 1];
	int     mindiff, minprot, i, d;

	/* If extptr is 0 then the first array of extrct holds the result
	 * of the "best difference" to date, which is those transitions
	 * which occur in "state" but not in the proto which, to date,
	 * has the fewest differences between itself and "state".  If
	 * extptr is 1 then the second array of extrct hold the best
	 * difference.  The two arrays are toggled between so that the
	 * best difference to date can be kept around and also a difference
	 * just created by checking against a candidate "best" proto.
	 */

	extptr = 0;

	/* If the state has too few out-transitions, don't bother trying to
	 * compact its tables.
	 */

	if ((totaltrans * 100) < (numecs * PROTO_SIZE_PERCENTAGE))
		mkentry (state, numecs, statenum, JAMSTATE, totaltrans);

	else {
		/* "checkcom" is true if we should only check "state" against
		 * protos which have the same "comstate" value.
		 */
		int     checkcom =

			comfreq * 100 > totaltrans * CHECK_COM_PERCENTAGE;

		minprot = firstprot;
		mindiff = totaltrans;

		if (checkcom) {
			/* Find first proto which has the same "comstate". */
			for (i = firstprot; i != NIL; i = protnext[i])
				if (protcomst[i] == comstate) {
					minprot = i;
					mindiff = tbldiff (state, minprot,
							   extrct[extptr]);
					break;
				}
		}

		else {
			/* Since we've decided that the most common destination
			 * out of "state" does not occur with a high enough
			 * frequency, we set the "comstate" to zero, assuring
			 * that if this state is entered into the proto list,
			 * it will not be considered a template.
			 */
			comstate = 0;

			if (firstprot != NIL) {
				minprot = firstprot;
				mindiff = tbldiff (state, minprot,
						   extrct[extptr]);
			}
		}

		/* We now have the first interesting proto in "minprot".  If
		 * it matches within the tolerances set for the first proto,
		 * we don't want to bother scanning the rest of the proto list
		 * to see if we have any other reasonable matches.
		 */

		if (mindiff * 100 >
		    totaltrans * FIRST_MATCH_DIFF_PERCENTAGE) {
			/* Not a good enough match.  Scan the rest of the
			 * protos.
			 */
			for (i = minprot; i != NIL; i = protnext[i]) {
				d = tbldiff (state, i, extrct[1 - extptr]);
				if (d < mindiff) {
					extptr = 1 - extptr;
					mindiff = d;
					minprot = i;
				}
			}
		}

		/* Check if the proto we've decided on as our best bet is close
		 * enough to the state we want to match to be usable.
		 */

		if (mindiff * 100 >
		    totaltrans * ACCEPTABLE_DIFF_PERCENTAGE) {
			/* No good.  If the state is homogeneous enough,
			 * we make a template out of it.  Otherwise, we
			 * make a proto.
			 */

			if (comfreq * 100 >=
			    totaltrans * TEMPLATE_SAME_PERCENTAGE)
					mktemplate (state, statenum,
						    comstate);

			else {
				mkprot (state, statenum, comstate);
				mkentry (state, numecs, statenum,
					 JAMSTATE, totaltrans);
			}
		}

		else {		/* use the proto */
			mkentry (extrct[extptr], numecs, statenum,
				 prottbl[minprot], mindiff);

			/* If this state was sufficiently different from the
			 * proto we built it from, make it, too, a proto.
			 */

			if (mindiff * 100 >=
			    totaltrans * NEW_PROTO_DIFF_PERCENTAGE)
					mkprot (state, statenum, comstate);

			/* Since mkprot added a new proto to the proto queue,
			 * it's possible that "minprot" is no longer on the
			 * proto queue (if it happened to have been the last
			 * entry, it would have been bumped off).  If it's
			 * not there, then the new proto took its physical
			 * place (though logically the new proto is at the
			 * beginning of the queue), so in that case the
			 * following call will do nothing.
			 */

			mv2front (minprot);
		}
	}
}


/* cmptmps - compress template table entries
 *
 * Template tables are compressed by using the 'template equivalence
 * classes', which are collections of transition character equivalence
 * classes which always appear together in templates - really meta-equivalence
 * classes.
 */

void    cmptmps ()
{
	int     tmpstorage[CSIZE + 1];
	register int *tmp = tmpstorage, i, j;
	int     totaltrans, trans;

	peakpairs = numtemps * numecs + tblend;

	if (usemecs) {
		/* Create equivalence classes based on data gathered on
		 * template transitions.
		 */
		nummecs = cre8ecs (tecfwd, tecbck, numecs);
	}

	else
		nummecs = numecs;

	while (lastdfa + numtemps + 1 >= current_max_dfas)
		increase_max_dfas ();

	/* Loop through each template. */

	for (i = 1; i <= numtemps; ++i) {
		/* Number of non-jam transitions out of this template. */
		totaltrans = 0;

		for (j = 1; j <= numecs; ++j) {
			trans = tnxt[numecs * i + j];

			if (usemecs) {
				/* The absolute value of tecbck is the
				 * meta-equivalence class of a given
				 * equivalence class, as set up by cre8ecs().
				 */
				if (tecbck[j] > 0) {
					tmp[tecbck[j]] = trans;

					if (trans > 0)
						++totaltrans;
				}
			}

			else {
				tmp[j] = trans;

				if (trans > 0)
					++totaltrans;
			}
		}

		/* It is assumed (in a rather subtle way) in the skeleton
		 * that if we're using meta-equivalence classes, the def[]
		 * entry for all templates is the jam template, i.e.,
		 * templates never default to other non-jam table entries
		 * (e.g., another template)
		 */

		/* Leave room for the jam-state after the last real state. */
		mkentry (tmp, nummecs, lastdfa + i + 1, JAMSTATE,
			 totaltrans);
	}
}



/* expand_nxt_chk - expand the next check arrays */

void    expand_nxt_chk ()
{
	register int old_max = current_max_xpairs;

	current_max_xpairs += MAX_XPAIRS_INCREMENT;

	++num_reallocs;

	nxt = reallocate_integer_array (nxt, current_max_xpairs);
	chk = reallocate_integer_array (chk, current_max_xpairs);

	zero_out ((char *) (chk + old_max),
		  (size_t) (MAX_XPAIRS_INCREMENT * sizeof (int)));
}


/* find_table_space - finds a space in the table for a state to be placed
 *
 * synopsis
 *     int *state, numtrans, block_start;
 *     int find_table_space();
 *
 *     block_start = find_table_space( state, numtrans );
 *
 * State is the state to be added to the full speed transition table.
 * Numtrans is the number of out-transitions for the state.
 *
 * find_table_space() returns the position of the start of the first block (in
 * chk) able to accommodate the state
 *
 * In determining if a state will or will not fit, find_table_space() must take
 * into account the fact that an end-of-buffer state will be added at [0],
 * and an action number will be added in [-1].
 */

int     find_table_space (state, numtrans)
     int    *state, numtrans;
{
	/* Firstfree is the position of the first possible occurrence of two
	 * consecutive unused records in the chk and nxt arrays.
	 */
	register int i;
	register int *state_ptr, *chk_ptr;
	register int *ptr_to_last_entry_in_state;

	/* If there are too many out-transitions, put the state at the end of
	 * nxt and chk.
	 */
	if (numtrans > MAX_XTIONS_FULL_INTERIOR_FIT) {
		/* If table is empty, return the first available spot in
		 * chk/nxt, which should be 1.
		 */
		if (tblend < 2)
			return 1;

		/* Start searching for table space near the end of
		 * chk/nxt arrays.
		 */
		i = tblend - numecs;
	}

	else
		/* Start searching for table space from the beginning
		 * (skipping only the elements which will definitely not
		 * hold the new state).
		 */
		i = firstfree;

	while (1) {		/* loops until a space is found */
		while (i + numecs >= current_max_xpairs)
			expand_nxt_chk ();

		/* Loops until space for end-of-buffer and action number
		 * are found.
		 */
		while (1) {
			/* Check for action number space. */
			if (chk[i - 1] == 0) {
				/* Check for end-of-buffer space. */
				if (chk[i] == 0)
					break;

				else
					/* Since i != 0, there is no use
					 * checking to see if (++i) - 1 == 0,
					 * because that's the same as i == 0,
					 * so we skip a space.
					 */
					i += 2;
			}

			else
				++i;

			while (i + numecs >= current_max_xpairs)
				expand_nxt_chk ();
		}

		/* If we started search from the beginning, store the new
		 * firstfree for the next call of find_table_space().
		 */
		if (numtrans <= MAX_XTIONS_FULL_INTERIOR_FIT)
			firstfree = i + 1;

		/* Check to see if all elements in chk (and therefore nxt)
		 * that are needed for the new state have not yet been taken.
		 */

		state_ptr = &state[1];
		ptr_to_last_entry_in_state = &chk[i + numecs + 1];

		for (chk_ptr = &chk[i + 1];
		     chk_ptr != ptr_to_last_entry_in_state; ++chk_ptr)
			if (*(state_ptr++) != 0 && *chk_ptr != 0)
				break;

		if (chk_ptr == ptr_to_last_entry_in_state)
			return i;

		else
			++i;
	}
}


/* inittbl - initialize transition tables
 *
 * Initializes "firstfree" to be one beyond the end of the table.  Initializes
 * all "chk" entries to be zero.
 */
void    inittbl ()
{
	register int i;

	zero_out ((char *) chk,

		  (size_t) (current_max_xpairs * sizeof (int)));

	tblend = 0;
	firstfree = tblend + 1;
	numtemps = 0;

	if (usemecs) {
		/* Set up doubly-linked meta-equivalence classes; these
		 * are sets of equivalence classes which all have identical
		 * transitions out of TEMPLATES.
		 */

		tecbck[1] = NIL;

		for (i = 2; i <= numecs; ++i) {
			tecbck[i] = i - 1;
			tecfwd[i - 1] = i;
		}

		tecfwd[numecs] = NIL;
	}
}


/* mkdeftbl - make the default, "jam" table entries */

void    mkdeftbl ()
{
	int     i;

	jamstate = lastdfa + 1;

	++tblend;		/* room for transition on end-of-buffer character */

	while (tblend + numecs >= current_max_xpairs)
		expand_nxt_chk ();

	/* Add in default end-of-buffer transition. */
	nxt[tblend] = end_of_buffer_state;
	chk[tblend] = jamstate;

	for (i = 1; i <= numecs; ++i) {
		nxt[tblend + i] = 0;
		chk[tblend + i] = jamstate;
	}

	jambase = tblend;

	base[jamstate] = jambase;
	def[jamstate] = 0;

	tblend += numecs;
	++numtemps;
}


/* mkentry - create base/def and nxt/chk entries for transition array
 *
 * synopsis
 *   int state[numchars + 1], numchars, statenum, deflink, totaltrans;
 *   mkentry( state, numchars, statenum, deflink, totaltrans );
 *
 * "state" is a transition array "numchars" characters in size, "statenum"
 * is the offset to be used into the base/def tables, and "deflink" is the
 * entry to put in the "def" table entry.  If "deflink" is equal to
 * "JAMSTATE", then no attempt will be made to fit zero entries of "state"
 * (i.e., jam entries) into the table.  It is assumed that by linking to
 * "JAMSTATE" they will be taken care of.  In any case, entries in "state"
 * marking transitions to "SAME_TRANS" are treated as though they will be
 * taken care of by whereever "deflink" points.  "totaltrans" is the total
 * number of transitions out of the state.  If it is below a certain threshold,
 * the tables are searched for an interior spot that will accommodate the
 * state array.
 */

void    mkentry (state, numchars, statenum, deflink, totaltrans)
     register int *state;
     int     numchars, statenum, deflink, totaltrans;
{
	register int minec, maxec, i, baseaddr;
	int     tblbase, tbllast;

	if (totaltrans == 0) {	/* there are no out-transitions */
		if (deflink == JAMSTATE)
			base[statenum] = JAMSTATE;
		else
			base[statenum] = 0;

		def[statenum] = deflink;
		return;
	}

	for (minec = 1; minec <= numchars; ++minec) {
		if (state[minec] != SAME_TRANS)
			if (state[minec] != 0 || deflink != JAMSTATE)
				break;
	}

	if (totaltrans == 1) {
		/* There's only one out-transition.  Save it for later to fill
		 * in holes in the tables.
		 */
		stack1 (statenum, minec, state[minec], deflink);
		return;
	}

	for (maxec = numchars; maxec > 0; --maxec) {
		if (state[maxec] != SAME_TRANS)
			if (state[maxec] != 0 || deflink != JAMSTATE)
				break;
	}

	/* Whether we try to fit the state table in the middle of the table
	 * entries we have already generated, or if we just take the state
	 * table at the end of the nxt/chk tables, we must make sure that we
	 * have a valid base address (i.e., non-negative).  Note that
	 * negative base addresses dangerous at run-time (because indexing
	 * the nxt array with one and a low-valued character will access
	 * memory before the start of the array.
	 */

	/* Find the first transition of state that we need to worry about. */
	if (totaltrans * 100 <= numchars * INTERIOR_FIT_PERCENTAGE) {
		/* Attempt to squeeze it into the middle of the tables. */
		baseaddr = firstfree;

		while (baseaddr < minec) {
			/* Using baseaddr would result in a negative base
			 * address below; find the next free slot.
			 */
			for (++baseaddr; chk[baseaddr] != 0; ++baseaddr) ;
		}

		while (baseaddr + maxec - minec + 1 >= current_max_xpairs)
			expand_nxt_chk ();

		for (i = minec; i <= maxec; ++i)
			if (state[i] != SAME_TRANS &&
			    (state[i] != 0 || deflink != JAMSTATE) &&
			    chk[baseaddr + i - minec] != 0) {	/* baseaddr unsuitable - find another */
				for (++baseaddr;
				     baseaddr < current_max_xpairs &&
				     chk[baseaddr] != 0; ++baseaddr) ;

				while (baseaddr + maxec - minec + 1 >=
				       current_max_xpairs)
						expand_nxt_chk ();

				/* Reset the loop counter so we'll start all
				 * over again next time it's incremented.
				 */

				i = minec - 1;
			}
	}

	else {
		/* Ensure that the base address we eventually generate is
		 * non-negative.
		 */
		baseaddr = MAX (tblend + 1, minec);
	}

	tblbase = baseaddr - minec;
	tbllast = tblbase + maxec;

	while (tbllast + 1 >= current_max_xpairs)
		expand_nxt_chk ();

	base[statenum] = tblbase;
	def[statenum] = deflink;

	for (i = minec; i <= maxec; ++i)
		if (state[i] != SAME_TRANS)
			if (state[i] != 0 || deflink != JAMSTATE) {
				nxt[tblbase + i] = state[i];
				chk[tblbase + i] = statenum;
			}

	if (baseaddr == firstfree)
		/* Find next free slot in tables. */
		for (++firstfree; chk[firstfree] != 0; ++firstfree) ;

	tblend = MAX (tblend, tbllast);
}


/* mk1tbl - create table entries for a state (or state fragment) which
 *            has only one out-transition
 */

void    mk1tbl (state, sym, onenxt, onedef)
     int     state, sym, onenxt, onedef;
{
	if (firstfree < sym)
		firstfree = sym;

	while (chk[firstfree] != 0)
		if (++firstfree >= current_max_xpairs)
			expand_nxt_chk ();

	base[state] = firstfree - sym;
	def[state] = onedef;
	chk[firstfree] = state;
	nxt[firstfree] = onenxt;

	if (firstfree > tblend) {
		tblend = firstfree++;

		if (firstfree >= current_max_xpairs)
			expand_nxt_chk ();
	}
}


/* mkprot - create new proto entry */

void    mkprot (state, statenum, comstate)
     int     state[], statenum, comstate;
{
	int     i, slot, tblbase;

	if (++numprots >= MSP || numecs * numprots >= PROT_SAVE_SIZE) {
		/* Gotta make room for the new proto by dropping last entry in
		 * the queue.
		 */
		slot = lastprot;
		lastprot = protprev[lastprot];
		protnext[lastprot] = NIL;
	}

	else
		slot = numprots;

	protnext[slot] = firstprot;

	if (firstprot != NIL)
		protprev[firstprot] = slot;

	firstprot = slot;
	prottbl[slot] = statenum;
	protcomst[slot] = comstate;

	/* Copy state into save area so it can be compared with rapidly. */
	tblbase = numecs * (slot - 1);

	for (i = 1; i <= numecs; ++i)
		protsave[tblbase + i] = state[i];
}


/* mktemplate - create a template entry based on a state, and connect the state
 *              to it
 */

void    mktemplate (state, statenum, comstate)
     int     state[], statenum, comstate;
{
	int     i, numdiff, tmpbase, tmp[CSIZE + 1];
	Char    transset[CSIZE + 1];
	int     tsptr;

	++numtemps;

	tsptr = 0;

	/* Calculate where we will temporarily store the transition table
	 * of the template in the tnxt[] array.  The final transition table
	 * gets created by cmptmps().
	 */

	tmpbase = numtemps * numecs;

	if (tmpbase + numecs >= current_max_template_xpairs) {
		current_max_template_xpairs +=
			MAX_TEMPLATE_XPAIRS_INCREMENT;

		++num_reallocs;

		tnxt = reallocate_integer_array (tnxt,
						 current_max_template_xpairs);
	}

	for (i = 1; i <= numecs; ++i)
		if (state[i] == 0)
			tnxt[tmpbase + i] = 0;
		else {
			transset[tsptr++] = i;
			tnxt[tmpbase + i] = comstate;
		}

	if (usemecs)
		mkeccl (transset, tsptr, tecfwd, tecbck, numecs, 0);

	mkprot (tnxt + tmpbase, -numtemps, comstate);

	/* We rely on the fact that mkprot adds things to the beginning
	 * of the proto queue.
	 */

	numdiff = tbldiff (state, firstprot, tmp);
	mkentry (tmp, numecs, statenum, -numtemps, numdiff);
}


/* mv2front - move proto queue element to front of queue */

void    mv2front (qelm)
     int     qelm;
{
	if (firstprot != qelm) {
		if (qelm == lastprot)
			lastprot = protprev[lastprot];

		protnext[protprev[qelm]] = protnext[qelm];

		if (protnext[qelm] != NIL)
			protprev[protnext[qelm]] = protprev[qelm];

		protprev[qelm] = NIL;
		protnext[qelm] = firstprot;
		protprev[firstprot] = qelm;
		firstprot = qelm;
	}
}


/* place_state - place a state into full speed transition table
 *
 * State is the statenum'th state.  It is indexed by equivalence class and
 * gives the number of the state to enter for a given equivalence class.
 * Transnum is the number of out-transitions for the state.
 */

void    place_state (state, statenum, transnum)
     int    *state, statenum, transnum;
{
	register int i;
	register int *state_ptr;
	int     position = find_table_space (state, transnum);

	/* "base" is the table of start positions. */
	base[statenum] = position;

	/* Put in action number marker; this non-zero number makes sure that
	 * find_table_space() knows that this position in chk/nxt is taken
	 * and should not be used for another accepting number in another
	 * state.
	 */
	chk[position - 1] = 1;

	/* Put in end-of-buffer marker; this is for the same purposes as
	 * above.
	 */
	chk[position] = 1;

	/* Place the state into chk and nxt. */
	state_ptr = &state[1];

	for (i = 1; i <= numecs; ++i, ++state_ptr)
		if (*state_ptr != 0) {
			chk[position + i] = i;
			nxt[position + i] = *state_ptr;
		}

	if (position + numecs > tblend)
		tblend = position + numecs;
}


/* stack1 - save states with only one out-transition to be processed later
 *
 * If there's room for another state on the "one-transition" stack, the
 * state is pushed onto it, to be processed later by mk1tbl.  If there's
 * no room, we process the sucker right now.
 */

void    stack1 (statenum, sym, nextstate, deflink)
     int     statenum, sym, nextstate, deflink;
{
	if (onesp >= ONE_STACK_SIZE - 1)
		mk1tbl (statenum, sym, nextstate, deflink);

	else {
		++onesp;
		onestate[onesp] = statenum;
		onesym[onesp] = sym;
		onenext[onesp] = nextstate;
		onedef[onesp] = deflink;
	}
}


/* tbldiff - compute differences between two state tables
 *
 * "state" is the state array which is to be extracted from the pr'th
 * proto.  "pr" is both the number of the proto we are extracting from
 * and an index into the save area where we can find the proto's complete
 * state table.  Each entry in "state" which differs from the corresponding
 * entry of "pr" will appear in "ext".
 *
 * Entries which are the same in both "state" and "pr" will be marked
 * as transitions to "SAME_TRANS" in "ext".  The total number of differences
 * between "state" and "pr" is returned as function value.  Note that this
 * number is "numecs" minus the number of "SAME_TRANS" entries in "ext".
 */

int     tbldiff (state, pr, ext)
     int     state[], pr, ext[];
{
	register int i, *sp = state, *ep = ext, *protp;
	register int numdiff = 0;

	protp = &protsave[numecs * (pr - 1)];

	for (i = numecs; i > 0; --i) {
		if (*++protp == *++sp)
			*++ep = SAME_TRANS;
		else {
			*++ep = *sp;
			++numdiff;
		}
	}

	return numdiff;
}