summaryrefslogtreecommitdiff
path: root/tblcmp.c
diff options
context:
space:
mode:
Diffstat (limited to 'tblcmp.c')
-rw-r--r--tblcmp.c853
1 files changed, 853 insertions, 0 deletions
diff --git a/tblcmp.c b/tblcmp.c
new file mode 100644
index 0000000..a56aaab
--- /dev/null
+++ b/tblcmp.c
@@ -0,0 +1,853 @@
+/* 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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 08:34:36 +0000