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TBLCMP.C
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1988-10-09
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/* tblcmp - table compression routines */
/*
* Copyright (c) 1987, the University of California
*
* 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 program may be redistributed. Enhancements and derivative works
* may be created provided the new works, if made available to the general
* public, are made available for use by anyone.
*/
#include "flexdef.h"
/* 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.
*/
bldtbl( state, statenum, totaltrans, comstate, comfreq )
int state[], statenum, totaltrans, comstate, comfreq;
{
int extptr, extrct[2][CSIZE + 1];
int mindiff, minprot, i, d;
int checkcom;
/* 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
*/
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
*
* synopsis
* cmptmps();
*
* 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. until this point, the tables for templates have been stored
* up at the top end of the nxt array; they will now be compressed and have
* table entries made for them.
*/
cmptmps()
{
int tmpstorage[CSIZE + 1];
register int *tmp = tmpstorage, i, j;
int totaltrans, trans;
peakpairs = numtemps * numecs + tblend;
if ( usemecs )
{
/* create equivalence classes base on data gathered on template
* transitions
*/
nummecs = cre8ecs( tecfwd, tecbck, numecs );
}
else
nummecs = numecs;
if ( lastdfa + numtemps + 1 >= current_max_dfas )
increase_max_dfas();
/* loop through each template */
for ( i = 1; i <= numtemps; ++i )
{
totaltrans = 0; /* number of non-jam transitions out of this template */
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 */
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 );
bzero( (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_FOR_FULL_INTERIOR_FIT )
{
/* if table is empty, return the first available spot in chk/nxt,
* which should be 1
*/
if ( tblend < 2 )
return ( 1 );
i = tblend - numecs; /* start searching for table space near the
* end of chk/nxt arrays
*/
}
else
i = firstfree; /* start searching for table space from the
* beginning (skipping only the elements
* which will definitely not hold the new
* state)
*/
while ( 1 ) /* loops until a space is found */
{
if ( i + numecs > current_max_xpairs )
expand_nxt_chk();
/* loops until space for end-of-buffer and action number are found */
while ( 1 )
{
if ( chk[i - 1] == 0 ) /* check for action number space */
{
if ( chk[i] == 0 ) /* check for end-of-buffer space */
break;
else
i += 2; /* 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
*/
}
else
++i;
if ( 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_FOR_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;
}
}
/* genctbl - generates full speed compressed transition table
*
* synopsis
* genctbl();
*/
genctbl()
{
register int i;
/* table of verify for transition and offset to next state */
printf( "static struct yy_trans_info yy_transition[%d] =\n",
tblend + numecs + 1 );
printf( " {\n" );
/* We want the transition to be represented as the offset to the
* next state, not the actual state number, which is what it currently is.
* The offset is base[nxt[i]] - base[chk[i]]. That's just the
* difference between the starting points of the two involved states
* (to - from).
*
* first, though, we need to find some way to put in our end-of-buffer
* flags and states. We do this by making a state with absolutely no
* transitions. We put it at the end of the table.
*/
/* at this point, we're guaranteed that there's enough room in nxt[]
* and chk[] to hold tblend + numecs entries. We need just two slots.
* One for the action and one for the end-of-buffer transition. We
* now *assume* that we're guaranteed the only character we'll try to
* index this nxt/chk pair with is EOB, i.e., 0, so we don't have to
* make sure there's room for jam entries for other characters.
*/
base[lastdfa + 1] = tblend + 2;
nxt[tblend + 1] = END_OF_BUFFER_ACTION;
chk[tblend + 1] = numecs + 1;
chk[tblend + 2] = 1; /* anything but EOB */
nxt[tblend + 2] = 0; /* so that "make test" won't show arb. differences */
/* make sure every state has a end-of-buffer transition and an action # */
for ( i = 0; i <= lastdfa; ++i )
{
chk[base[i]] = EOB_POSITION;
chk[base[i] - 1] = ACTION_POSITION;
nxt[base[i] - 1] = dfaacc[i].dfaacc_state; /* action number */
}
for ( i = 0; i <= lastsc * 2; ++i )
nxt[base[i] - 1] = DEFAULT_ACTION;
dataline = 0;
datapos = 0;
for ( i = 0; i <= tblend; ++i )
{
if ( chk[i] == EOB_POSITION )
transition_struct_out( 0, base[lastdfa + 1] - i );
else if ( chk[i] == ACTION_POSITION )
transition_struct_out( 0, nxt[i] );
else if ( chk[i] > numecs || chk[i] == 0 )
transition_struct_out( 0, 0 ); /* unused slot */
else /* verify, transition */
transition_struct_out( chk[i], base[nxt[i]] - (i - chk[i]) );
}
/* here's the final, end-of-buffer state */
transition_struct_out( chk[tblend + 1], nxt[tblend + 1] );
transition_struct_out( chk[tblend + 2], nxt[tblend + 2] );
printf( " };\n" );
printf( "\n" );
/* table of pointers to start states */
printf( "static struct yy_trans_info *yy_state_ptr[%d] =\n",
lastsc * 2 + 1 );
printf( " {\n" );
for ( i = 0; i <= lastsc * 2; ++i )
printf( " &yy_transition[%d],\n", base[i] );
printf( " };\n" );
if ( useecs )
genecs();
}
/* gentabs - generate data statements for the transition tables
*
* synopsis
* gentabs();
*/
gentabs()
{
int i, j, k, *accset, nacc, *acc_array;
char clower();
/* *everything* is done in terms of arrays starting at 1, so provide
* a null entry for the zero element of all FTL arrays
*/
static char ftl_long_decl[] = "static long int %c[%d] =\n { 0,\n";
static char ftl_short_decl[] = "static short int %c[%d] =\n { 0,\n";
static char ftl_char_decl[] = "static char %c[%d] =\n { 0,\n";
acc_array = allocate_integer_array( current_max_dfas );
nummt = 0;
if ( fulltbl )
jambase = lastdfa + 1; /* home of "jam" pseudo-state */
printf( "#define YY_JAM %d\n", jamstate );
printf( "#define YY_JAM_BASE %d\n", jambase );
if ( usemecs )
printf( "#define YY_TEMPLATE %d\n", lastdfa + 2 );
if ( reject )
{
/* write out accepting list and pointer list
* first we generate the ACCEPT array. In the process, we compute
* the indices that will go into the ALIST array, and save the
* indices in the dfaacc array
*/
printf( accnum > 127 ? ftl_short_decl : ftl_char_decl,
ACCEPT, max( numas, 1 ) + 1 );
j = 1; /* index into ACCEPT array */
for ( i = 1; i <= lastdfa; ++i )
{
acc_array[i] = j;
if ( accsiz[i] != 0 )
{
accset = dfaacc[i].dfaacc_set;
nacc = accsiz[i];
if ( trace )
fprintf( stderr, "state # %d accepts: ", i );
for ( k = 1; k <= nacc; ++k )
{
++j;
mkdata( accset[k] );
if ( trace )
{
fprintf( stderr, "[%d]", accset[k] );
if ( k < nacc )
fputs( ", ", stderr );
else
putc( '\n', stderr );
}
}
}
}
/* add accepting number for the "jam" state */
acc_array[i] = j;
dataend();
}
else
{
for ( i = 1; i <= lastdfa; ++i )
acc_array[i] = dfaacc[i].dfaacc_state;
acc_array[i] = 0; /* add (null) accepting number for jam state */
}
/* spit out ALIST array. If we're doing "reject", it'll be pointers
* into the ACCEPT array. Otherwise it's actual accepting numbers.
* In either case, we just dump the numbers.
*/
/* "lastdfa + 2" is the size of ALIST; includes room for FTL arrays
* beginning at 0 and for "jam" state
*/
k = lastdfa + 2;
if ( reject )
/* we put a "cap" on the table associating lists of accepting
* numbers with state numbers. This is needed because we tell
* where the end of an accepting list is by looking at where
* the list for the next state starts.
*/
++k;
printf( ((reject && numas > 126) || accnum > 127) ?
ftl_short_decl : ftl_char_decl, ALIST, k );
/* set up default actions */
for ( i = 1; i <= lastsc * 2; ++i )
acc_array[i] = DEFAULT_ACTION;
acc_array[end_of_buffer_state] = END_OF_BUFFER_ACTION;
for ( i = 1; i <= lastdfa; ++i )
{
mkdata( acc_array[i] );
if ( ! reject && trace && acc_array[i] )
fprintf( stderr, "state # %d accepts: [%d]\n", i, acc_array[i] );
}
/* add entry for "jam" state */
mkdata( acc_array[i] );
if ( reject )
/* add "cap" for the list */
mkdata( acc_array[i] );
dataend();
if ( useecs )
genecs();
if ( usemecs )
{
/* write out meta-equivalence classes (used to index templates with) */
if ( trace )
fputs( "\n\nMeta-Equivalence Classes:\n", stderr );
printf( ftl_char_decl, MATCHARRAY, numecs + 1 );
for ( i = 1; i <= numecs; ++i )
{
if ( trace )
fprintf( stderr, "%d = %d\n", i, abs( tecbck[i] ) );
mkdata( abs( tecbck[i] ) );
}
dataend();
}
if ( ! fulltbl )
{
int total_states = lastdfa + numtemps;
printf( tblend > MAX_SHORT ? ftl_long_decl : ftl_short_decl,
BASEARRAY, total_states + 1 );
for ( i = 1; i <= lastdfa; ++i )
{
register int d = def[i];
if ( base[i] == JAMSTATE )
base[i] = jambase;
if ( d == JAMSTATE )
def[i] = jamstate;
else if ( d < 0 )
{
/* template reference */
++tmpuses;
def[i] = lastdfa - d + 1;
}
mkdata( base[i] );
}
/* generate jam state's base index */
mkdata( base[i] );
for ( ++i /* skip jam state */; i <= total_states; ++i )
{
mkdata( base[i] );
def[i] = jamstate;
}
dataend();
printf( tblend > MAX_SHORT ? ftl_long_decl : ftl_short_decl,
DEFARRAY, total_states + 1 );
for ( i = 1; i <= total_states; ++i )
mkdata( def[i] );
dataend();
printf( lastdfa > MAX_SHORT ? ftl_long_decl : ftl_short_decl,
NEXTARRAY, tblend + 1 );
for ( i = 1; i <= tblend; ++i )
{
if ( nxt[i] == 0 || chk[i] == 0 )
nxt[i] = jamstate; /* new state is the JAM state */
mkdata( nxt[i] );
}
dataend();
printf( lastdfa > MAX_SHORT ? ftl_long_decl : ftl_short_decl,
CHECKARRAY, tblend + 1 );
for ( i = 1; i <= tblend; ++i )
{
if ( chk[i] == 0 )
++nummt;
mkdata( chk[i] );
}
dataend();
}
}
/* generate equivalence-class tables */
genecs()
{
register int i, j;
static char ftl_char_decl[] = "static char %c[%d] =\n { 0,\n";
int numrows;
printf( ftl_char_decl, ECARRAY, CSIZE + 1 );
for ( i = 1; i <= CSIZE; ++i )
{
if ( caseins && (i >= 'A') && (i <= 'Z') )
ecgroup[i] = ecgroup[clower( i )];
ecgroup[i] = abs( ecgroup[i] );
mkdata( ecgroup[i] );
}
dataend();
if ( trace )
{
fputs( "\n\nEquivalence Classes:\n\n", stderr );
numrows = (CSIZE + 1) / 8;
for ( j = 1; j <= numrows; ++j )
{
for ( i = j; i <= CSIZE; i = i + numrows )
{
if ( i >= 1 && i <= 31 )
fprintf( stderr, "^%c = %-2d",
'A' + i - 1, ecgroup[i] );
else if ( i >= 32 && i <= 126 )
fprintf( stderr, " %c = %-2d", i, ecgroup[i] );
else if ( i == 127 )
fprintf( stderr, "^@ = %-2d", ecgroup[i] );
else
fprintf( stderr, "\nSomething Weird: %d = %d\n", i,
ecgroup[i] );
putc( '\t', stderr );
}
putc( '\n', stderr );
}
}
}
/* inittbl - initialize transition tables
*
* synopsis
* inittbl();
*
* Initializes "firstfree" to be one beyond the end of the table. Initializes
* all "chk" entries to be zero. Note that templates are built in their
* own tbase/tdef tables. They are shifted down to be contiguous
* with the non-template entries during table generation.
*/
inittbl()
{
register int i;
bzero( (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;
}
}
/* make_tables - generate transition tables
*
* synopsis
* make_tables();
*
* Generates transition tables and finishes generating output file
*/
make_tables()
{
if ( fullspd )
{ /* need to define YY_TRANS_OFFSET_TYPE as a size large
* enough to hold the biggest offset
*/
int total_table_size = tblend + numecs + 1;
printf( "#define YY_TRANS_OFFSET_TYPE %s\n",
total_table_size > MAX_SHORT ? "long" : "short" );
}
if ( fullspd || fulltbl )
skelout();
/* compute the tables and copy them to output file */
if ( fullspd )
genctbl();
else
gentabs();
skelout();
(void) fclose( temp_action_file );
temp_action_file = fopen( action_file_name, "r" );
/* copy prolog from action_file to output file */
action_out();
skelout();
/* copy actions from action_file to output file */
action_out();
skelout();
/* copy remainder of input to output */
line_directive_out( stdout );
(void) flexscan(); /* copy remainder of input to output */
}
/* mkdeftbl - make the default, "jam" table entries
*
* synopsis
* mkdeftbl();
*/
mkdeftbl()
{
int i;
jamstate = lastdfa + 1;
if ( tblend + numecs > current_max_xpairs )
expand_nxt_chk();
for ( i = 1; i <= numecs; ++i )
{
nxt[tblend + i] = 0;
chk[tblend + i] = jamstate;
}
jambase = tblend;
base[jamstate] = jambase;
/* should generate a run-time array bounds check if
* ever used as a default
*/
def[jamstate] = BAD_SUBSCRIPT;
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.
*/
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 not only are
* negative base addresses dangerous at run-time (because indexing the
* next array with one and a low-valued character might generate an
* array-out-of-bounds error message), but at compile-time negative
* base addresses denote TEMPLATES.
*/
/* 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 tabls */
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 )
;
}
if ( baseaddr + maxec - minec >= current_max_xpairs )
expand_nxt_chk();
for ( i = minec; i <= maxec; ++i )
if ( state[i] != SAME_TRANS )
if ( state[i] != 0 || deflink != JAMSTATE )
if ( chk[baseaddr + i - minec] != 0 )
{ /* baseaddr unsuitable - find another */
for ( ++baseaddr;
baseaddr < current_max_xpairs &&
chk[baseaddr] != 0;
++baseaddr )
;
if ( baseaddr + maxec - minec >= 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;
if ( tbllast >= 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
*
* synopsis
* int state, sym, onenxt, onedef;
* mk1tbl( state, sym, onenxt, onedef );
*/
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
*
* synopsis
* int state[], statenum, comstate;
* mkprot( state, statenum, comstate );
*/
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
*
* synopsis
* int state[], statenum, comstate, totaltrans;
* mktemplate( state, statenum, comstate, totaltrans );
*/
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 );
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
*
* synopsis
* int qelm;
* mv2front( qelm );
*/
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;
}
}
/* ntod - convert an ndfa to a dfa
*
* synopsis
* ntod();
*
* creates the dfa corresponding to the ndfa we've constructed. the
* dfa starts out in state #1.
*/
ntod()
{
int *accset, ds, nacc, newds;
int duplist[CSIZE + 1], sym, hashval, numstates, dsize;
int targfreq[CSIZE + 1], targstate[CSIZE + 1], state[CSIZE + 1];
int *nset, *dset;
int targptr, totaltrans, i, comstate, comfreq, targ;
int *epsclosure(), snstods(), symlist[CSIZE + 1];
/* this is so find_table_space(...) will know where to start looking in
* chk/nxt for unused records for space to put in the state
*/
if ( fullspd )
firstfree = 0;
accset = allocate_integer_array( accnum + 1 );
nset = allocate_integer_array( current_max_dfa_size );
todo_head = todo_next = 0;
#define ADD_QUEUE_ELEMENT(element) \
if ( ++element >= current_max_dfas ) \
{ /* check for queue overflowing */ \
if ( todo_head == 0 ) \
increase_max_dfas(); \
else \
element = 0; \
}
#define NEXT_QUEUE_ELEMENT(element) ((element + 1) % (current_max_dfas + 1))
for ( i = 0; i <= CSIZE; ++i )
{
duplist[i] = NIL;
symlist[i] = false;
}
for ( i = 0; i <= accnum; ++i )
accset[i] = NIL;
if ( trace )
{
dumpnfa( scset[1] );
fputs( "\n\nDFA Dump:\n\n", stderr );
}
inittbl();
if ( fullspd )
{
for ( i = 0; i <= numecs; ++i )
state[i] = 0;
place_state( state, 0, 0 );
}
if ( fulltbl )
{
/* declare it "short" because it's a real long-shot that that
* won't be large enough
*/
printf( "static short int %c[][%d] =\n {\n", NEXTARRAY,
numecs + 1 ); /* '}' so vi doesn't get too confused */
/* generate 0 entries for state #0 */
for ( i = 0; i <= numecs; ++i )
mk2data( 0 );
/* force ',' and dataflush() next call to mk2data */
datapos = NUMDATAITEMS;
/* force extra blank line next dataflush() */
dataline = NUMDATALINES;
}
/* create the first states */
for ( i = 1; i <= lastsc * 2; ++i )
{
numstates = 1;
/* for each start condition, make one state for the case when
* we're at the beginning of the line (the '%' operator) and
* one for the case when we're not
*/
if ( i % 2 == 1 )
nset[numstates] = scset[(i / 2) + 1];
else
nset[numstates] = mkbranch( scbol[i / 2], scset[i / 2] );
nset = epsclosure( nset, &numstates, accset, &nacc, &hashval );
if ( snstods( nset, numstates, accset, nacc, hashval, &ds ) )
{
numas = numas + nacc;
totnst = totnst + numstates;
todo[todo_next] = ds;
ADD_QUEUE_ELEMENT(todo_next);
}
}
if ( fulltbl )
{
if ( ! snstods( nset, 0, accset, 0, 0, &end_of_buffer_state ) )
flexfatal( "could not create unique end-of-buffer state" );
numas += 1;
todo[todo_next] = end_of_buffer_state;
ADD_QUEUE_ELEMENT(todo_next);
}
while ( todo_head != todo_next )
{
targptr = 0;
totaltrans = 0;
for ( i = 1; i <= numecs; ++i )
state[i] = 0;
ds = todo[todo_head];
todo_head = NEXT_QUEUE_ELEMENT(todo_head);
dset = dss[ds];
dsize = dfasiz[ds];
if ( trace )
fprintf( stderr, "state # %d:\n", ds );
sympartition( dset, dsize, symlist, duplist );
for ( sym = 1; sym <= numecs; ++sym )
{
if ( symlist[sym] )
{
symlist[sym] = 0;
if ( duplist[sym] == NIL )
{ /* symbol has unique out-transitions */
numstates = symfollowset( dset, dsize, sym, nset );
nset = epsclosure( nset, &numstates, accset,
&nacc, &hashval );
if ( snstods( nset, numstates, accset,
nacc, hashval, &newds ) )
{
totnst = totnst + numstates;
todo[todo_next] = newds;
ADD_QUEUE_ELEMENT(todo_next);
numas = numas + nacc;
}
state[sym] = newds;
if ( trace )
fprintf( stderr, "\t%d\t%d\n", sym, newds );
targfreq[++targptr] = 1;
targstate[targptr] = newds;
++numuniq;
}
else
{
/* sym's equivalence class has the same transitions
* as duplist(sym)'s equivalence class
*/
targ = state[duplist[sym]];
state[sym] = targ;
if ( trace )
fprintf( stderr, "\t%d\t%d\n", sym, targ );
/* update frequency count for destination state */
i = 0;
while ( targstate[++i] != targ )
;
++targfreq[i];
++numdup;
}
++totaltrans;
duplist[sym] = NIL;
}
}
numsnpairs = numsnpairs + totaltrans;
if ( caseins && ! useecs )
{
register int j;
for ( i = 'A', j = 'a'; i <= 'Z'; ++i, ++j )
state[i] = state[j];
}
if ( fulltbl )
{
/* supply array's 0-element */
if ( ds == end_of_buffer_state )
mk2data( 0 );
else
mk2data( end_of_buffer_state );
for ( i = 1; i <= numecs; ++i )
mk2data( state[i] );
/* force ',' and dataflush() next call to mk2data */
datapos = NUMDATAITEMS;
/* force extra blank line next dataflush() */
dataline = NUMDATALINES;
}
else if ( fullspd )
place_state( state, ds, totaltrans );
else
{
/* determine which destination state is the most common, and
* how many transitions to it there are
*/
comfreq = 0;
comstate = 0;
for ( i = 1; i <= targptr; ++i )
if ( targfreq[i] > comfreq )
{
comfreq = targfreq[i];
comstate = targstate[i];
}
bldtbl( state, ds, totaltrans, comstate, comfreq );
}
}
if ( fulltbl )
dataend();
else
{
cmptmps(); /* create compressed template entries */
/* create tables for all the states with only one out-transition */
while ( onesp > 0 )
{
mk1tbl( onestate[onesp], onesym[onesp], onenext[onesp],
onedef[onesp] );
--onesp;
}
mkdeftbl();
}
}
/* place_state - place a state into full speed transition table
*
* synopsis
* int *state, statenum, transnum;
* place_state( state, statenum, transnum );
*
* 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.
*/
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
*
* synopsis
* int statenum, sym, nextstate, deflink;
* stack1( statenum, sym, nextstate, deflink );
*
* if there's room for another state one 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.
*/
stack1( statenum, sym, nextstate, deflink )
int statenum, sym, nextstate, deflink;
{
if ( onesp >= ONE_STACK_SIZE )
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
*
* synopsis
* int state[], pr, ext[];
* int tbldiff, numdifferences;
* numdifferences = tbldiff( state, pr, ext )
*
* "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 );
}