639 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			639 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #include "defs.h"
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| 
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| typedef
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|   struct shorts
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|     {
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|       struct shorts *next;
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|       short value;
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|     }
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|   shorts;
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| 
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| int tokensetsize;
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| short *lookaheads;
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| short *LAruleno;
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| unsigned *LA;
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| short *accessing_symbol;
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| core **state_table;
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| shifts **shift_table;
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| reductions **reduction_table;
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| short *goto_map;
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| short *from_state;
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| short *to_state;
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| 
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| short **transpose();
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| 
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| static int infinity;
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| static int maxrhs;
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| static int ngotos;
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| static unsigned *F;
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| static short **includes;
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| static shorts **lookback;
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| static short **R;
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| static short *INDEX;
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| static short *VERTICES;
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| static int top;
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| 
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| 
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| lalr()
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| {
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|     tokensetsize = WORDSIZE(ntokens);
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| 
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|     set_state_table();
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|     set_accessing_symbol();
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|     set_shift_table();
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|     set_reduction_table();
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|     set_maxrhs();
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|     initialize_LA();
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|     set_goto_map();
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|     initialize_F();
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|     build_relations();
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|     compute_FOLLOWS();
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|     compute_lookaheads();
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| }
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| 
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| 
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| 
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| set_state_table()
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| {
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|     register core *sp;
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| 
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|     state_table = NEW2(nstates, core *);
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|     for (sp = first_state; sp; sp = sp->next)
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| 	state_table[sp->number] = sp;
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| }
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| 
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| 
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| 
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| set_accessing_symbol()
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| {
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|     register core *sp;
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| 
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|     accessing_symbol = NEW2(nstates, short);
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|     for (sp = first_state; sp; sp = sp->next)
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| 	accessing_symbol[sp->number] = sp->accessing_symbol;
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| }
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| 
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| 
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| 
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| set_shift_table()
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| {
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|     register shifts *sp;
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| 
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|     shift_table = NEW2(nstates, shifts *);
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|     for (sp = first_shift; sp; sp = sp->next)
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| 	shift_table[sp->number] = sp;
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| }
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| 
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| 
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| 
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| set_reduction_table()
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| {
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|     register reductions *rp;
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| 
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|     reduction_table = NEW2(nstates, reductions *);
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|     for (rp = first_reduction; rp; rp = rp->next)
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| 	reduction_table[rp->number] = rp;
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| }
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| 
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| 
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| 
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| set_maxrhs()
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| {
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|   register short *itemp;
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|   register short *item_end;
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|   register int length;
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|   register int max;
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| 
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|   length = 0;
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|   max = 0;
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|   item_end = ritem + nitems;
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|   for (itemp = ritem; itemp < item_end; itemp++)
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|     {
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|       if (*itemp >= 0)
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| 	{
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| 	  length++;
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| 	}
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|       else
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| 	{
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| 	  if (length > max) max = length;
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| 	  length = 0;
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| 	}
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|     }
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| 
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|   maxrhs = max;
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| }
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| 
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| 
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| 
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| initialize_LA()
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| {
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|   register int i, j, k;
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|   register reductions *rp;
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| 
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|   lookaheads = NEW2(nstates + 1, short);
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| 
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|   k = 0;
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|   for (i = 0; i < nstates; i++)
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|     {
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|       lookaheads[i] = k;
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|       rp = reduction_table[i];
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|       if (rp)
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| 	k += rp->nreds;
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|     }
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|   lookaheads[nstates] = k;
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| 
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|   LA = NEW2(k * tokensetsize, unsigned);
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|   LAruleno = NEW2(k, short);
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|   lookback = NEW2(k, shorts *);
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| 
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|   k = 0;
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|   for (i = 0; i < nstates; i++)
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|     {
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|       rp = reduction_table[i];
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|       if (rp)
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| 	{
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| 	  for (j = 0; j < rp->nreds; j++)
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| 	    {
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| 	      LAruleno[k] = rp->rules[j];
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| 	      k++;
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| 	    }
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| 	}
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|     }
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| }
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| 
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| 
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| set_goto_map()
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| {
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|   register shifts *sp;
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|   register int i;
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|   register int symbol;
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|   register int k;
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|   register short *temp_map;
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|   register int state2;
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|   register int state1;
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| 
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|   goto_map = NEW2(nvars + 1, short) - ntokens;
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|   temp_map = NEW2(nvars + 1, short) - ntokens;
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| 
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|   ngotos = 0;
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|   for (sp = first_shift; sp; sp = sp->next)
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|     {
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|       for (i = sp->nshifts - 1; i >= 0; i--)
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| 	{
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| 	  symbol = accessing_symbol[sp->shift[i]];
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| 
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| 	  if (ISTOKEN(symbol)) break;
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| 
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| 	  if (ngotos == MAXSHORT)
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| 	    fatal("too many gotos");
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| 
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| 	  ngotos++;
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| 	  goto_map[symbol]++;
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|         }
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|     }
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| 
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|   k = 0;
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|   for (i = ntokens; i < nsyms; i++)
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|     {
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|       temp_map[i] = k;
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|       k += goto_map[i];
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|     }
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| 
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|   for (i = ntokens; i < nsyms; i++)
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|     goto_map[i] = temp_map[i];
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| 
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|   goto_map[nsyms] = ngotos;
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|   temp_map[nsyms] = ngotos;
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| 
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|   from_state = NEW2(ngotos, short);
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|   to_state = NEW2(ngotos, short);
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| 
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|   for (sp = first_shift; sp; sp = sp->next)
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|     {
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|       state1 = sp->number;
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|       for (i = sp->nshifts - 1; i >= 0; i--)
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| 	{
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| 	  state2 = sp->shift[i];
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| 	  symbol = accessing_symbol[state2];
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| 
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| 	  if (ISTOKEN(symbol)) break;
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| 
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| 	  k = temp_map[symbol]++;
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| 	  from_state[k] = state1;
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| 	  to_state[k] = state2;
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| 	}
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|     }
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| 
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|   FREE(temp_map + ntokens);
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| }
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| 
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| 
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| 
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| /*  Map_goto maps a state/symbol pair into its numeric representation.	*/
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| 
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| int
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| map_goto(state, symbol)
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| int state;
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| int symbol;
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| {
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|     register int high;
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|     register int low;
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|     register int middle;
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|     register int s;
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| 
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|     low = goto_map[symbol];
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|     high = goto_map[symbol + 1];
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| 
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|     for (;;)
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|     {
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| 	assert(low <= high);
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| 	middle = (low + high) >> 1;
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| 	s = from_state[middle];
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| 	if (s == state)
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| 	    return (middle);
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| 	else if (s < state)
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| 	    low = middle + 1;
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| 	else
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| 	    high = middle - 1;
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|     }
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| }
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| 
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| 
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| 
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| initialize_F()
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| {
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|   register int i;
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|   register int j;
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|   register int k;
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|   register shifts *sp;
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|   register short *edge;
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|   register unsigned *rowp;
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|   register short *rp;
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|   register short **reads;
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|   register int nedges;
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|   register int stateno;
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|   register int symbol;
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|   register int nwords;
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| 
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|   nwords = ngotos * tokensetsize;
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|   F = NEW2(nwords, unsigned);
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| 
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|   reads = NEW2(ngotos, short *);
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|   edge = NEW2(ngotos + 1, short);
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|   nedges = 0;
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| 
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|   rowp = F;
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|   for (i = 0; i < ngotos; i++)
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|     {
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|       stateno = to_state[i];
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|       sp = shift_table[stateno];
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| 
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|       if (sp)
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| 	{
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| 	  k = sp->nshifts;
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| 
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| 	  for (j = 0; j < k; j++)
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| 	    {
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| 	      symbol = accessing_symbol[sp->shift[j]];
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| 	      if (ISVAR(symbol))
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| 		break;
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| 	      SETBIT(rowp, symbol);
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| 	    }
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| 
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| 	  for (; j < k; j++)
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| 	    {
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| 	      symbol = accessing_symbol[sp->shift[j]];
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| 	      if (nullable[symbol])
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| 		edge[nedges++] = map_goto(stateno, symbol);
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| 	    }
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| 	
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| 	  if (nedges)
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| 	    {
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| 	      reads[i] = rp = NEW2(nedges + 1, short);
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| 
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| 	      for (j = 0; j < nedges; j++)
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| 		rp[j] = edge[j];
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| 
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| 	      rp[nedges] = -1;
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| 	      nedges = 0;
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| 	    }
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| 	}
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| 
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|       rowp += tokensetsize;
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|     }
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| 
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|   SETBIT(F, 0);
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|   digraph(reads);
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| 
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|   for (i = 0; i < ngotos; i++)
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|     {
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|       if (reads[i])
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| 	FREE(reads[i]);
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|     }
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| 
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|   FREE(reads);
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|   FREE(edge);
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| }
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| 
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| 
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| 
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| build_relations()
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| {
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|   register int i;
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|   register int j;
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|   register int k;
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|   register short *rulep;
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|   register short *rp;
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|   register shifts *sp;
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|   register int length;
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|   register int nedges;
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|   register int done;
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|   register int state1;
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|   register int stateno;
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|   register int symbol1;
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|   register int symbol2;
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|   register short *shortp;
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|   register short *edge;
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|   register short *states;
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|   register short **new_includes;
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| 
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|   includes = NEW2(ngotos, short *);
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|   edge = NEW2(ngotos + 1, short);
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|   states = NEW2(maxrhs + 1, short);
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| 
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|   for (i = 0; i < ngotos; i++)
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|     {
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|       nedges = 0;
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|       state1 = from_state[i];
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|       symbol1 = accessing_symbol[to_state[i]];
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| 
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|       for (rulep = derives[symbol1]; *rulep >= 0; rulep++)
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| 	{
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| 	  length = 1;
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| 	  states[0] = state1;
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| 	  stateno = state1;
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| 
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| 	  for (rp = ritem + rrhs[*rulep]; *rp >= 0; rp++)
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| 	    {
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| 	      symbol2 = *rp;
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| 	      sp = shift_table[stateno];
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| 	      k = sp->nshifts;
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| 
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| 	      for (j = 0; j < k; j++)
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| 		{
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| 		  stateno = sp->shift[j];
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| 		  if (accessing_symbol[stateno] == symbol2) break;
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| 		}
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| 
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| 	      states[length++] = stateno;
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| 	    }
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| 
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| 	  add_lookback_edge(stateno, *rulep, i);
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| 
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| 	  length--;
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| 	  done = 0;
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| 	  while (!done)
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| 	    {
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| 	      done = 1;
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| 	      rp--;
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| 	      if (ISVAR(*rp))
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| 		{
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| 		  stateno = states[--length];
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| 		  edge[nedges++] = map_goto(stateno, *rp);
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| 		  if (nullable[*rp] && length > 0) done = 0;
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| 		}
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| 	    }
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| 	}
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| 
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|       if (nedges)
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| 	{
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| 	  includes[i] = shortp = NEW2(nedges + 1, short);
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| 	  for (j = 0; j < nedges; j++)
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| 	    shortp[j] = edge[j];
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| 	  shortp[nedges] = -1;
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| 	}
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|     }
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| 
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|   new_includes = transpose(includes, ngotos);
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| 
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|   for (i = 0; i < ngotos; i++)
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|     if (includes[i])
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|       FREE(includes[i]);
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| 
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|   FREE(includes);
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| 
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|   includes = new_includes;
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| 
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|   FREE(edge);
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|   FREE(states);
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| }
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| 
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| 
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| add_lookback_edge(stateno, ruleno, gotono)
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| int stateno, ruleno, gotono;
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| {
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|     register int i, k;
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|     register int found;
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|     register shorts *sp;
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| 
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|     i = lookaheads[stateno];
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|     k = lookaheads[stateno + 1];
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|     found = 0;
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|     while (!found && i < k)
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|     {
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| 	if (LAruleno[i] == ruleno)
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| 	    found = 1;
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| 	else
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| 	    ++i;
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|     }
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|     assert(found);
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| 
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|     sp = NEW(shorts);
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|     sp->next = lookback[i];
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|     sp->value = gotono;
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|     lookback[i] = sp;
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| }
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| 
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| 
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| 
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| short **
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| transpose(R, n)
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| short **R;
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| int n;
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| {
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|   register short **new_R;
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|   register short **temp_R;
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|   register short *nedges;
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|   register short *sp;
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|   register int i;
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|   register int k;
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| 
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|   nedges = NEW2(n, short);
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| 
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|   for (i = 0; i < n; i++)
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|     {
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|       sp = R[i];
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|       if (sp)
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| 	{
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| 	  while (*sp >= 0)
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| 	    nedges[*sp++]++;
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| 	}
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|     }
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| 
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|   new_R = NEW2(n, short *);
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|   temp_R = NEW2(n, short *);
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| 
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|   for (i = 0; i < n; i++)
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|     {
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|       k = nedges[i];
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|       if (k > 0)
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| 	{
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| 	  sp = NEW2(k + 1, short);
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| 	  new_R[i] = sp;
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| 	  temp_R[i] = sp;
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| 	  sp[k] = -1;
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| 	}
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|     }
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| 
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|   FREE(nedges);
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| 
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|   for (i = 0; i < n; i++)
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|     {
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|       sp = R[i];
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|       if (sp)
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| 	{
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| 	  while (*sp >= 0)
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| 	    *temp_R[*sp++]++ = i;
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| 	}
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|     }
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| 
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|   FREE(temp_R);
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| 
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|   return (new_R);
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| }
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| 
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| 
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| 
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| compute_FOLLOWS()
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| {
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|   digraph(includes);
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| }
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| 
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| 
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| compute_lookaheads()
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| {
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|   register int i, n;
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|   register unsigned *fp1, *fp2, *fp3;
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|   register shorts *sp, *next;
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|   register unsigned *rowp;
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| 
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|   rowp = LA;
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|   n = lookaheads[nstates];
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|   for (i = 0; i < n; i++)
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|     {
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|       fp3 = rowp + tokensetsize;
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|       for (sp = lookback[i]; sp; sp = sp->next)
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| 	{
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| 	  fp1 = rowp;
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| 	  fp2 = F + tokensetsize * sp->value;
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| 	  while (fp1 < fp3)
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| 	    *fp1++ |= *fp2++;
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| 	}
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|       rowp = fp3;
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|     }
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| 
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|   for (i = 0; i < n; i++)
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|     for (sp = lookback[i]; sp; sp = next)
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|       {
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|         next = sp->next;
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|         FREE(sp);
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|       }
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| 
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|   FREE(lookback);
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|   FREE(F);
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| }
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| 
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| 
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| digraph(relation)
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| short **relation;
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| {
 | |
|   register int i;
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| 
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|   infinity = ngotos + 2;
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|   INDEX = NEW2(ngotos + 1, short);
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|   VERTICES = NEW2(ngotos + 1, short);
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|   top = 0;
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| 
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|   R = relation;
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| 
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|   for (i = 0; i < ngotos; i++)
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|     INDEX[i] = 0;
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| 
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|   for (i = 0; i < ngotos; i++)
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|     {
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|       if (INDEX[i] == 0 && R[i])
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| 	traverse(i);
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|     }
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| 
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|   FREE(INDEX);
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|   FREE(VERTICES);
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| }
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| 
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| 
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| 
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| traverse(i)
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| register int i;
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| {
 | |
|   register unsigned *fp1;
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|   register unsigned *fp2;
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|   register unsigned *fp3;
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|   register int j;
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|   register short *rp;
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| 
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|   int height;
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|   unsigned *base;
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| 
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|   VERTICES[++top] = i;
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|   INDEX[i] = height = top;
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| 
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|   base = F + i * tokensetsize;
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|   fp3 = base + tokensetsize;
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| 
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|   rp = R[i];
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|   if (rp)
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|     {
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|       while ((j = *rp++) >= 0)
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| 	{
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| 	  if (INDEX[j] == 0)
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| 	    traverse(j);
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| 
 | |
| 	  if (INDEX[i] > INDEX[j])
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| 	    INDEX[i] = INDEX[j];
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| 
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| 	  fp1 = base;
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| 	  fp2 = F + j * tokensetsize;
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| 
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| 	  while (fp1 < fp3)
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| 	    *fp1++ |= *fp2++;
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| 	}
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|     }
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| 
 | |
|   if (INDEX[i] == height)
 | |
|     {
 | |
|       for (;;)
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| 	{
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| 	  j = VERTICES[top--];
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| 	  INDEX[j] = infinity;
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| 
 | |
| 	  if (i == j)
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| 	    break;
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| 
 | |
| 	  fp1 = base;
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| 	  fp2 = F + j * tokensetsize;
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| 
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| 	  while (fp1 < fp3)
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| 	    *fp2++ = *fp1++;
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| 	}
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|     }
 | |
| }
 | 
