5fe69bb518
more likely to have the right value. Remove superfluous assignments. Found by: LLVM/Clang Static Checker
314 lines
6.1 KiB
C
314 lines
6.1 KiB
C
/*
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* Copyright (c) 1989 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Robert Paul Corbett.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if 0
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#ifndef lint
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static char sccsid[] = "@(#)closure.c 5.3 (Berkeley) 5/24/93";
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#endif
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#endif
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <stdlib.h>
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#include "defs.h"
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short *itemset;
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short *itemsetend;
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unsigned *ruleset;
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static void set_EFF(void);
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#ifdef DEBUG
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static void print_closure(int);
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static void print_EFF();
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static void print_first_derives();
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#endif
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static unsigned *first_derives;
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static unsigned *EFF;
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static void
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set_EFF()
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{
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unsigned *row;
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int symbol;
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short *sp;
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int rowsize;
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int i;
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int rule;
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rowsize = WORDSIZE(nvars);
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EFF = NEW2(nvars * rowsize, unsigned);
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row = EFF;
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for (i = start_symbol; i < nsyms; i++)
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{
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sp = derives[i];
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for (rule = *sp; rule > 0; rule = *++sp)
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{
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symbol = ritem[rrhs[rule]];
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if (ISVAR(symbol))
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{
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symbol -= start_symbol;
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SETBIT(row, symbol);
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}
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}
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row += rowsize;
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}
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reflexive_transitive_closure(EFF, nvars);
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#ifdef DEBUG
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print_EFF();
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#endif
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}
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void
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set_first_derives()
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{
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unsigned *rrow;
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unsigned *vrow;
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int j;
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unsigned k;
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unsigned cword = 0;
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short *rp;
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int rule;
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int i;
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int rulesetsize;
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int varsetsize;
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rulesetsize = WORDSIZE(nrules);
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varsetsize = WORDSIZE(nvars);
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first_derives = NEW2(nvars * rulesetsize, unsigned) - ntokens * rulesetsize;
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set_EFF();
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rrow = first_derives + ntokens * rulesetsize;
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for (i = start_symbol; i < nsyms; i++)
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{
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vrow = EFF + ((i - ntokens) * varsetsize);
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k = BITS_PER_WORD;
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for (j = start_symbol; j < nsyms; k++, j++)
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{
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if (k >= BITS_PER_WORD)
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{
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cword = *vrow++;
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k = 0;
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}
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if (cword & (1 << k))
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{
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rp = derives[j];
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while ((rule = *rp++) >= 0)
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{
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SETBIT(rrow, rule);
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}
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}
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}
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rrow += rulesetsize;
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}
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#ifdef DEBUG
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print_first_derives();
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#endif
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FREE(EFF);
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}
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void
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closure(nucleus, n)
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short *nucleus;
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int n;
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{
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int ruleno;
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unsigned word;
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unsigned i;
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short *csp;
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unsigned *dsp;
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unsigned *rsp;
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int rulesetsize;
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short *csend;
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unsigned *rsend;
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int symbol;
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int itemno;
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rulesetsize = WORDSIZE(nrules);
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rsend = ruleset + rulesetsize;
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for (rsp = ruleset; rsp < rsend; rsp++)
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*rsp = 0;
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csend = nucleus + n;
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for (csp = nucleus; csp < csend; ++csp)
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{
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symbol = ritem[*csp];
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if (ISVAR(symbol))
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{
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dsp = first_derives + symbol * rulesetsize;
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rsp = ruleset;
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while (rsp < rsend)
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*rsp++ |= *dsp++;
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}
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}
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ruleno = 0;
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itemsetend = itemset;
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csp = nucleus;
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for (rsp = ruleset; rsp < rsend; ++rsp)
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{
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word = *rsp;
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if (word)
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{
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for (i = 0; i < BITS_PER_WORD; ++i)
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{
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if (word & (1 << i))
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{
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itemno = rrhs[ruleno+i];
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while (csp < csend && *csp < itemno)
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*itemsetend++ = *csp++;
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*itemsetend++ = itemno;
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while (csp < csend && *csp == itemno)
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++csp;
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}
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}
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}
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ruleno += BITS_PER_WORD;
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}
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while (csp < csend)
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*itemsetend++ = *csp++;
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#ifdef DEBUG
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print_closure(n);
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#endif
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}
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void
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finalize_closure()
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{
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FREE(itemset);
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FREE(ruleset);
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FREE(first_derives + ntokens * WORDSIZE(nrules));
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}
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#ifdef DEBUG
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static void
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print_closure(n)
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int n;
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{
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short *isp;
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printf("\n\nn = %d\n\n", n);
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for (isp = itemset; isp < itemsetend; isp++)
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printf(" %d\n", *isp);
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}
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static void
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print_EFF()
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{
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int i, j;
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unsigned *rowp;
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unsigned word;
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unsigned k;
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printf("\n\nEpsilon Free Firsts\n");
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for (i = start_symbol; i < nsyms; i++)
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{
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printf("\n%s", symbol_name[i]);
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rowp = EFF + ((i - start_symbol) * WORDSIZE(nvars));
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word = *rowp++;
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k = BITS_PER_WORD;
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for (j = 0; j < nvars; k++, j++)
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{
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if (k >= BITS_PER_WORD)
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{
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word = *rowp++;
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k = 0;
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}
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if (word & (1 << k))
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printf(" %s", symbol_name[start_symbol + j]);
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}
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}
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}
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static void
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print_first_derives()
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{
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int i;
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int j;
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unsigned *rp;
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unsigned cword;
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unsigned k;
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printf("\n\n\nFirst Derives\n");
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for (i = start_symbol; i < nsyms; i++)
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{
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printf("\n%s derives\n", symbol_name[i]);
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rp = first_derives + i * WORDSIZE(nrules);
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k = BITS_PER_WORD;
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for (j = 0; j <= nrules; k++, j++)
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{
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if (k >= BITS_PER_WORD)
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{
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cword = *rp++;
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k = 0;
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}
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if (cword & (1 << k))
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printf(" %d\n", j);
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}
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}
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fflush(stdout);
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}
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#endif
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