Flex version 2.4.7 from LBL

Reviewed by:	Geoff.

1 files changed, 888 insertions, 0 deletions

diff --git a/usr.bin/lex/tblcmp.c b/usr.bin/lex/tblcmp.c
new file mode 100644
index 0000000..224dd13
--- /dev/null
+++ b/usr.bin/lex/tblcmp.c
@@ -0,0 +1,888 @@
+/* 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.
+ *
+ * Redistribution and use in source and binary forms are permitted provided
+ * that: (1) source distributions retain this entire copyright notice and
+ * comment, and (2) distributions including binaries display the following
+ * acknowledgement:  ``This product includes software developed by the
+ * University of California, Berkeley and its contributors'' in the
+ * documentation or other materials provided with the distribution and in
+ * all advertising materials mentioning features or use of this software.
+ * 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.
+ */
+
+/* $Header: /home/daffy/u0/vern/flex/RCS/tblcmp.c,v 2.10 93/12/07 10:18:30 vern Exp $ */
+
+#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),
+		MAX_XPAIRS_INCREMENT * sizeof( int ) / sizeof( char ) );
+	}
+
+
+/* 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,
+		current_max_xpairs * sizeof( int ) / sizeof( char ) );
+
+	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;
+	}