mirror of
https://git.savannah.gnu.org/git/bison.git
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* src/reduce.c: Convert to use bitset.h, not hand coded BSet.
This commit is contained in:
@@ -1,3 +1,7 @@
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2002-03-04 Akim Demaille <akim@epita.fr>
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* src/reduce.c: Convert to use bitset.h, not hand coded BSet.
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2002-03-04 Akim Demaille <akim@epita.fr>
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2002-03-04 Akim Demaille <akim@epita.fr>
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* src/closure.c (ruleset): Be a bitset.
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* src/closure.c (ruleset): Be a bitset.
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141
src/reduce.c
141
src/reduce.c
@@ -34,62 +34,35 @@
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#include "reduce.h"
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#include "reduce.h"
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#include "reader.h"
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#include "reader.h"
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#include "getargs.h"
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#include "getargs.h"
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#include "bitset.h"
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typedef unsigned *BSet;
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typedef short *rule;
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typedef short *rule;
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/* Set of all nonterminals which are not useless. */
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/* Set of all nonterminals which are not useless. */
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static BSet N;
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static bitset N;
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/* Set of all rules which have no useless nonterminals in their RHS. */
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/* Set of all rules which have no useless nonterminals in their RHS. */
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static BSet P;
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static bitset P;
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/* Set of all accessible symbols. */
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/* Set of all accessible symbols. */
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static BSet V;
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static bitset V;
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/* Set of symbols used to define rule precedence (so they are
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/* Set of symbols used to define rule precedence (so they are
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`useless', but no warning should be issued). */
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`useless', but no warning should be issued). */
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static BSet V1;
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static bitset V1;
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static int nuseful_productions;
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static int nuseful_productions;
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static int nuseless_productions;
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static int nuseless_productions;
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static int nuseful_nonterminals;
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static int nuseful_nonterminals;
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int nuseless_nonterminals;
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int nuseless_nonterminals;
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static bool
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bits_equal (BSet L, BSet R, int n)
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{
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int i;
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for (i = n - 1; i >= 0; i--)
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if (L[i] != R[i])
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return FALSE;
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return TRUE;
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}
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static int
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static int
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nbits (unsigned i)
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bits_size (bitset S)
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{
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int count = 0;
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while (i != 0)
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{
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i ^= (i & ((unsigned) (-(int) i)));
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++count;
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}
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return count;
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}
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static int
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bits_size (BSet S, int n)
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{
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{
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int i, count = 0;
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int i, count = 0;
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for (i = n - 1; i >= 0; i--)
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BITSET_EXECUTE (S, 0, i, { ++count; });
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count += nbits (S[i]);
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return count;
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return count;
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}
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}
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@@ -100,7 +73,7 @@ bits_size (BSet S, int n)
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`-------------------------------------------------------------------*/
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`-------------------------------------------------------------------*/
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static bool
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static bool
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useful_production (int i, BSet N0)
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useful_production (int i, bitset N0)
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{
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{
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rule r;
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rule r;
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short n;
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short n;
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@@ -110,7 +83,7 @@ useful_production (int i, BSet N0)
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for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
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for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
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if (ISVAR (n = *r))
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if (ISVAR (n = *r))
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if (!BITISSET (N0, n - ntokens))
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if (!bitset_test (N0, n - ntokens))
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return FALSE;
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return FALSE;
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return TRUE;
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return TRUE;
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}
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}
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@@ -123,13 +96,15 @@ useful_production (int i, BSet N0)
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static void
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static void
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useless_nonterminals (void)
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useless_nonterminals (void)
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{
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{
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BSet Np, Ns;
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bitset Np, Ns;
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int i;
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int i;
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/* N is set as built. Np is set being built this iteration. P is
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/* N is set as built. Np is set being built this iteration. P is
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set of all productions which have a RHS all in N. */
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set of all productions which have a RHS all in N. */
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Np = XCALLOC (unsigned, WORDSIZE (nvars));
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Np = bitset_create (nvars, BITSET_FIXED);
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bitset_zero (Np);
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/* The set being computed is a set of nonterminals which can derive
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/* The set being computed is a set of nonterminals which can derive
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the empty string or strings consisting of all terminals. At each
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the empty string or strings consisting of all terminals. At each
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@@ -149,26 +124,25 @@ useless_nonterminals (void)
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while (1)
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while (1)
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{
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{
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for (i = WORDSIZE (nvars) - 1; i >= 0; i--)
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bitset_copy (Np, N);
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Np[i] = N[i];
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for (i = 1; i <= nrules; i++)
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for (i = 1; i <= nrules; i++)
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{
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{
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if (!BITISSET (P, i))
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if (!bitset_test (P, i))
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{
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{
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if (useful_production (i, N))
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if (useful_production (i, N))
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{
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{
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SETBIT (Np, rules[i].lhs - ntokens);
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bitset_set (Np, rules[i].lhs - ntokens);
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SETBIT (P, i);
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bitset_set (P, i);
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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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if (bits_equal (N, Np, WORDSIZE (nvars)))
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if (bitset_equal_p (N, Np))
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break;
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break;
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Ns = Np;
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Ns = Np;
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Np = N;
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Np = N;
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N = Ns;
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N = Ns;
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}
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}
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XFREE (N);
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bitset_free (N);
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N = Np;
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N = Np;
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}
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}
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@@ -176,7 +150,7 @@ useless_nonterminals (void)
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static void
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static void
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inaccessable_symbols (void)
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inaccessable_symbols (void)
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{
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{
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BSet Vp, Vs, Pp;
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bitset Vp, Vs, Pp;
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int i;
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int i;
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short t;
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short t;
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rule r;
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rule r;
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@@ -204,31 +178,32 @@ inaccessable_symbols (void)
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terminals are printed (if running in verbose mode) so that the
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terminals are printed (if running in verbose mode) so that the
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user can know. */
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user can know. */
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Vp = XCALLOC (unsigned, WORDSIZE (nsyms));
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Vp = bitset_create (nsyms, BITSET_FIXED);
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Pp = XCALLOC (unsigned, WORDSIZE (nrules + 1));
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bitset_zero (Vp);
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Pp = bitset_create (nrules + 1, BITSET_FIXED);
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bitset_zero (Pp);
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/* If the start symbol isn't useful, then nothing will be useful. */
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/* If the start symbol isn't useful, then nothing will be useful. */
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if (BITISSET (N, start_symbol - ntokens))
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if (bitset_test (N, start_symbol - ntokens))
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{
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{
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SETBIT (V, start_symbol);
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bitset_set (V, start_symbol);
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while (1)
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while (1)
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{
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{
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for (i = WORDSIZE (nsyms) - 1; i >= 0; i--)
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bitset_copy (Vp, V);
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Vp[i] = V[i];
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for (i = 1; i <= nrules; i++)
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for (i = 1; i <= nrules; i++)
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{
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{
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if (!BITISSET (Pp, i)
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if (!bitset_test (Pp, i)
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&& BITISSET (P, i)
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&& bitset_test (P, i)
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&& BITISSET (V, rules[i].lhs))
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&& bitset_test (V, rules[i].lhs))
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{
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{
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for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
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for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
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if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens))
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if (ISTOKEN (t = *r) || bitset_test (N, t - ntokens))
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SETBIT (Vp, t);
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bitset_set (Vp, t);
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SETBIT (Pp, i);
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bitset_set (Pp, i);
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}
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}
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}
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}
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if (bits_equal (V, Vp, WORDSIZE (nsyms)))
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if (bitset_equal_p (V, Vp))
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break;
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break;
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Vs = Vp;
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Vs = Vp;
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Vp = V;
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Vp = V;
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@@ -236,30 +211,30 @@ inaccessable_symbols (void)
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}
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}
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}
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}
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XFREE (V);
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bitset_free (V);
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V = Vp;
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V = Vp;
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/* Tokens 0, 1, and 2 are internal to Bison. Consider them useful. */
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/* Tokens 0, 1, and 2 are internal to Bison. Consider them useful. */
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SETBIT (V, 0); /* end-of-input token */
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bitset_set (V, 0); /* end-of-input token */
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SETBIT (V, 1); /* error token */
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bitset_set (V, 1); /* error token */
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SETBIT (V, 2); /* some undefined token */
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bitset_set (V, 2); /* some undefined token */
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XFREE (P);
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bitset_free (P);
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P = Pp;
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P = Pp;
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nuseful_productions = bits_size (P, WORDSIZE (nrules + 1));
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nuseful_productions = bits_size (P);
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nuseless_productions = nrules - nuseful_productions;
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nuseless_productions = nrules - nuseful_productions;
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nuseful_nonterminals = 0;
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nuseful_nonterminals = 0;
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for (i = ntokens; i < nsyms; i++)
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for (i = ntokens; i < nsyms; i++)
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if (BITISSET (V, i))
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if (bitset_test (V, i))
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nuseful_nonterminals++;
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nuseful_nonterminals++;
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nuseless_nonterminals = nvars - nuseful_nonterminals;
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nuseless_nonterminals = nvars - nuseful_nonterminals;
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/* A token that was used in %prec should not be warned about. */
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/* A token that was used in %prec should not be warned about. */
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for (i = 1; i < nrules; i++)
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for (i = 1; i < nrules; i++)
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if (rules[i].precsym != 0)
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if (rules[i].precsym != 0)
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SETBIT (V1, rules[i].precsym);
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bitset_set (V1, rules[i].precsym);
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}
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}
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static void
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static void
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@@ -284,7 +259,7 @@ reduce_grammar_tables (void)
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np = 0;
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np = 0;
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ni = 0;
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ni = 0;
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for (pn = 1; pn <= nrules; pn++)
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for (pn = 1; pn <= nrules; pn++)
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if (BITISSET (P, pn))
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if (bitset_test (P, pn))
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{
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{
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np++;
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np++;
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if (pn != np)
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if (pn != np)
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@@ -324,7 +299,7 @@ reduce_grammar_tables (void)
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{
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{
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int pn;
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int pn;
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for (pn = 1; pn <= nrules; pn++)
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for (pn = 1; pn <= nrules; pn++)
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rules[pn].useful = BITISSET (P, pn);
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rules[pn].useful = bitset_test (P, pn);
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}
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}
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}
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}
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@@ -344,10 +319,10 @@ nonterminals_reduce (void)
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short *nontermmap = XCALLOC (short, nvars) - ntokens;
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short *nontermmap = XCALLOC (short, nvars) - ntokens;
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n = ntokens;
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n = ntokens;
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for (i = ntokens; i < nsyms; i++)
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for (i = ntokens; i < nsyms; i++)
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if (BITISSET (V, i))
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if (bitset_test (V, i))
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nontermmap[i] = n++;
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nontermmap[i] = n++;
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for (i = ntokens; i < nsyms; i++)
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for (i = ntokens; i < nsyms; i++)
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if (!BITISSET (V, i))
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if (!bitset_test (V, i))
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nontermmap[i] = n++;
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nontermmap[i] = n++;
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@@ -405,7 +380,7 @@ reduce_output (FILE *out)
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bool b = FALSE;
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bool b = FALSE;
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int i;
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int i;
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for (i = 0; i < ntokens; i++)
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for (i = 0; i < ntokens; i++)
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if (!BITISSET (V, i) && !BITISSET (V1, i))
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if (!bitset_test (V, i) && !bitset_test (V1, i))
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{
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{
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if (!b)
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if (!b)
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fprintf (out, "%s\n\n", _("Terminals which are not used:"));
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fprintf (out, "%s\n\n", _("Terminals which are not used:"));
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@@ -523,10 +498,14 @@ reduce_grammar (void)
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/* Allocate the global sets used to compute the reduced grammar */
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/* Allocate the global sets used to compute the reduced grammar */
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N = XCALLOC (unsigned, WORDSIZE (nvars));
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N = bitset_create (nvars, BITSET_FIXED);
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P = XCALLOC (unsigned, WORDSIZE (nrules + 1));
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bitset_zero (N);
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V = XCALLOC (unsigned, WORDSIZE (nsyms));
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P = bitset_create (nrules + 1, BITSET_FIXED);
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V1 = XCALLOC (unsigned, WORDSIZE (nsyms));
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bitset_zero (P);
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V = bitset_create (nsyms, BITSET_FIXED);
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bitset_zero (V);
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V1 = bitset_create (nsyms, BITSET_FIXED);
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bitset_zero (V1);
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useless_nonterminals ();
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useless_nonterminals ();
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inaccessable_symbols ();
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inaccessable_symbols ();
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@@ -538,7 +517,7 @@ reduce_grammar (void)
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reduce_print ();
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reduce_print ();
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if (!BITISSET (N, start_symbol - ntokens))
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if (!bitset_test (N, start_symbol - ntokens))
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fatal (_("Start symbol %s does not derive any sentence"),
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fatal (_("Start symbol %s does not derive any sentence"),
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symbols[start_symbol]->tag);
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symbols[start_symbol]->tag);
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@@ -564,8 +543,8 @@ reduce_grammar (void)
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void
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void
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reduce_free (void)
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reduce_free (void)
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{
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{
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XFREE (N);
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bitset_free (N);
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XFREE (V);
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bitset_free (V);
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XFREE (V1);
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bitset_free (V1);
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XFREE (P);
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bitset_free (P);
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}
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}
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