mirror of https://github.com/YosysHQ/abc.git
1633 lines
53 KiB
C
1633 lines
53 KiB
C
/**************************************************************************************************
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MiniSat -- Copyright (c) 2005, Niklas Sorensson
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http://www.cs.chalmers.se/Cs/Research/FormalMethods/MiniSat/
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Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
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associated documentation files (the "Software"), to deal in the Software without restriction,
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including without limitation the rights to use, copy, modify, merge, publish, distribute,
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sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all copies or
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substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
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NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
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OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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**************************************************************************************************/
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// Modified to compile with MS Visual Studio 6.0 by Alan Mishchenko
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#include <stdio.h>
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#include <assert.h>
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#include <string.h>
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#include <math.h>
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#include "satSolver2.h"
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ABC_NAMESPACE_IMPL_START
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#define SAT_USE_ANALYZE_FINAL
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#define SAT_USE_PROOF_LOGGING
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//=================================================================================================
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// Debug:
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//#define VERBOSEDEBUG
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// For derivation output (verbosity level 2)
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#define L_IND "%-*d"
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#define L_ind solver2_dlevel(s)*3+3,solver2_dlevel(s)
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#define L_LIT "%sx%d"
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#define L_lit(p) lit_sign(p)?"~":"", (lit_var(p))
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static void printlits(lit* begin, lit* end)
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{
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int i;
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for (i = 0; i < end - begin; i++)
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printf(L_LIT" ",L_lit(begin[i]));
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}
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//=================================================================================================
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// Random numbers:
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// Returns a random float 0 <= x < 1. Seed must never be 0.
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static inline double drand(double* seed) {
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int q;
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*seed *= 1389796;
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q = (int)(*seed / 2147483647);
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*seed -= (double)q * 2147483647;
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return *seed / 2147483647; }
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// Returns a random integer 0 <= x < size. Seed must never be 0.
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static inline int irand(double* seed, int size) {
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return (int)(drand(seed) * size); }
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static inline int sat_float2int( float Val ) { union { int x; float y; } v; v.y = Val; return v.x; }
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static inline float sat_int2float( int Num ) { union { int x; float y; } v; v.x = Num; return v.y; }
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//=================================================================================================
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// Predeclarations:
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static void solver2_sort(void** array, int size, int(*comp)(const void *, const void *));
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//=================================================================================================
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// Variable datatype + minor functions:
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static const int var0 = 1;
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static const int var1 = 0;
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static const int varX = 3;
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struct varinfo_t
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{
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unsigned val : 2; // variable value
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unsigned pol : 1; // last polarity
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unsigned tag : 3; // conflict analysis tags
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unsigned lev : 26; // variable level
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};
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static inline int var_value (sat_solver2* s, int v) { return s->vi[v].val; }
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static inline int var_polar (sat_solver2* s, int v) { return s->vi[v].pol; }
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static inline int var_level (sat_solver2* s, int v) { return s->vi[v].lev; }
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static inline void var_set_value (sat_solver2* s, int v, int val ) { s->vi[v].val = val; }
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static inline void var_set_polar (sat_solver2* s, int v, int pol ) { s->vi[v].pol = pol; }
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static inline void var_set_level (sat_solver2* s, int v, int lev ) { s->vi[v].lev = lev; }
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// variable tags
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static inline int var_tag (sat_solver2* s, int v) { return s->vi[v].tag; }
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static inline void var_set_tag (sat_solver2* s, int v, int tag) {
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assert( tag > 0 && tag < 16 );
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if ( s->vi[v].tag == 0 )
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veci_push( &s->tagged, v );
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s->vi[v].tag = tag;
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}
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static inline void var_add_tag (sat_solver2* s, int v, int tag) {
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assert( tag > 0 && tag < 16 );
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if ( s->vi[v].tag == 0 )
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veci_push( &s->tagged, v );
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s->vi[v].tag |= tag;
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}
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static inline void solver2_clear_tags(sat_solver2* s, int start) {
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int i, * tagged = veci_begin(&s->tagged);
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for (i = start; i < veci_size(&s->tagged); i++)
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s->vi[tagged[i]].tag = 0;
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veci_resize(&s->tagged,start);
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}
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// level marks
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static inline int var_lev_mark (sat_solver2* s, int v) {
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return (veci_begin(&s->trail_lim)[var_level(s,v)] & 0x80000000) > 0;
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}
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static inline void var_lev_set_mark (sat_solver2* s, int v) {
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int level = var_level(s,v);
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assert( level < veci_size(&s->trail_lim) );
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veci_begin(&s->trail_lim)[level] |= 0x80000000;
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veci_push(&s->mark_levels, level);
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}
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static inline void solver2_clear_marks(sat_solver2* s) {
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int i, * mark_levels = veci_begin(&s->mark_levels);
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for (i = 0; i < veci_size(&s->mark_levels); i++)
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veci_begin(&s->trail_lim)[mark_levels[i]] &= 0x7FFFFFFF;
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veci_resize(&s->mark_levels,0);
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}
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// other inlines
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//static inline int var_reason (sat_solver2* s, int v) { return (s->reasons[v]&1) ? 0 : s->reasons[v] >> 1; }
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//static inline int lit_reason (sat_solver2* s, int l) { return (s->reasons[lit_var(l)&1]) ? 0 : s->reasons[lit_var(l)] >> 1; }
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static inline int var_reason (sat_solver2* s, int v) { return s->reasons[v]; }
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static inline int lit_reason (sat_solver2* s, int l) { return s->reasons[lit_var(l)]; }
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//=================================================================================================
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// Clause datatype + minor functions:
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typedef struct satset_t satset;
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struct satset_t // should have even number of entries!
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{
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unsigned learnt : 1;
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unsigned mark : 1;
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unsigned partA : 1;
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unsigned nLits : 29;
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int Id;
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lit pLits[0];
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};
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static inline int clause_size (int nLits) { return sizeof(satset)/4 + nLits; }
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static inline satset* get_clause (sat_solver2* s, int c) { return c ? (satset*)(veci_begin(&s->clauses) + c) : NULL; }
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static inline cla clause_id (sat_solver2* s, satset* c) { return (cla)((int *)c - veci_begin(&s->clauses)); }
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//static inline satset* var_unit_clause(sat_solver2* s, int v) { return (s->reasons[v]&1) ? get_clause(s, s->reasons[v] >> 1) : NULL; }
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//static inline void var_set_unit_clause(sat_solver2* s, int v, cla i){ assert(i && !s->reasons[v]); s->reasons[v] = (i << 1) | 1; }
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static inline satset* var_unit_clause(sat_solver2* s, int v) { return get_clause(s, s->units[v]); }
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static inline void var_set_unit_clause(sat_solver2* s, int v, cla i){ assert(v >= 0 && v < s->size && !s->units[v]); s->units[v] = i; s->nUnits++; }
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#define sat_solver_foreach_clause( s, c, i ) \
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for ( i = 16; (i < s->nMemSize) && (((c) = get_clause(s, i)), 1); i += clause_size(c->nLits) )
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#define sat_solver_foreach_learnt( s, c, i ) \
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for ( i = s->iFirstLearnt; (i < s->nMemSize) && (((c) = get_clause(s, i)), 1); i += clause_size(c->nLits) )
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//=================================================================================================
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// Simple helpers:
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static inline int solver2_dlevel(sat_solver2* s) { return veci_size(&s->trail_lim); }
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static inline veci* solver2_wlist(sat_solver2* s, lit l) { return &s->wlists[l]; }
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//=================================================================================================
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// Proof logging:
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static inline void proof_chain_start( sat_solver2* s, satset* c )
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{
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if ( s->fProofLogging )
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{
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s->iStartChain = veci_size(&s->proof_clas);
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veci_push(&s->proof_clas, 0);
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veci_push(&s->proof_clas, 0);
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veci_push(&s->proof_clas, c->learnt ? veci_begin(&s->claProofs)[c->Id] : clause_id(s,c) ^ 1 );
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veci_push(&s->proof_vars, 0);
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veci_push(&s->proof_vars, 0);
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veci_push(&s->proof_vars, 0);
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}
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}
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static inline void proof_chain_resolve( sat_solver2* s, satset* cls, int Var )
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{
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if ( s->fProofLogging )
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{
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satset* c = cls ? cls : var_unit_clause( s, Var );
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veci_push(&s->proof_clas, c->learnt ? veci_begin(&s->claProofs)[c->Id] : clause_id(s,c) ^ 1 );
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veci_push(&s->proof_vars, Var);
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}
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}
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static inline int proof_chain_stop( sat_solver2* s )
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{
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if ( s->fProofLogging )
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{
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int RetValue = s->iStartChain;
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satset* c = (satset*)(veci_begin(&s->proof_clas) + s->iStartChain);
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assert( s->iStartChain > 0 && s->iStartChain < veci_size(&s->proof_clas) );
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c->nLits = veci_size(&s->proof_clas) - s->iStartChain - 2;
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s->iStartChain = 0;
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return RetValue;
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}
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return 0;
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}
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//=================================================================================================
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// Variable order functions:
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static inline void order_update(sat_solver2* s, int v) // updateorder
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{
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int* orderpos = s->orderpos;
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int* heap = veci_begin(&s->order);
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int i = orderpos[v];
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int x = heap[i];
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int parent = (i - 1) / 2;
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assert(s->orderpos[v] != -1);
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while (i != 0 && s->activity[x] > s->activity[heap[parent]]){
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heap[i] = heap[parent];
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orderpos[heap[i]] = i;
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i = parent;
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parent = (i - 1) / 2;
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}
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heap[i] = x;
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orderpos[x] = i;
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}
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static inline void order_assigned(sat_solver2* s, int v)
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{
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}
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static inline void order_unassigned(sat_solver2* s, int v) // undoorder
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{
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int* orderpos = s->orderpos;
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if (orderpos[v] == -1){
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orderpos[v] = veci_size(&s->order);
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veci_push(&s->order,v);
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order_update(s,v);
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}
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}
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static inline int order_select(sat_solver2* s, float random_var_freq) // selectvar
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{
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int* heap = veci_begin(&s->order);
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int* orderpos = s->orderpos;
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// Random decision:
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if (drand(&s->random_seed) < random_var_freq){
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int next = irand(&s->random_seed,s->size);
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assert(next >= 0 && next < s->size);
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if (var_value(s, next) == varX)
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return next;
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}
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// Activity based decision:
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while (veci_size(&s->order) > 0){
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int next = heap[0];
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int size = veci_size(&s->order)-1;
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int x = heap[size];
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veci_resize(&s->order,size);
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orderpos[next] = -1;
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if (size > 0){
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unsigned act = s->activity[x];
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int i = 0;
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int child = 1;
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while (child < size){
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if (child+1 < size && s->activity[heap[child]] < s->activity[heap[child+1]])
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child++;
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assert(child < size);
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if (act >= s->activity[heap[child]])
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break;
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heap[i] = heap[child];
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orderpos[heap[i]] = i;
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i = child;
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child = 2 * child + 1;
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}
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heap[i] = x;
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orderpos[heap[i]] = i;
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}
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if (var_value(s, next) == varX)
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return next;
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}
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return var_Undef;
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}
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//=================================================================================================
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// Activity functions:
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#ifdef USE_FLOAT_ACTIVITY
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static inline void act_var_rescale(sat_solver2* s) {
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double* activity = s->activity;
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int i;
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for (i = 0; i < s->size; i++)
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activity[i] *= 1e-100;
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s->var_inc *= 1e-100;
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}
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static inline void act_clause_rescale(sat_solver2* s) {
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static int Total = 0;
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float * claActs = (float *)veci_begin(&s->claActs);
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int i, clk = clock();
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for (i = 0; i < veci_size(&s->claActs); i++)
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claActs[i] *= (float)1e-20;
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s->cla_inc *= (float)1e-20;
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printf( "Rescaling... Cla inc = %10.3f Conf = %10d ", s->cla_inc, s->stats.conflicts );
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Total += clock() - clk;
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Abc_PrintTime( 1, "Time", Total );
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}
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static inline void act_var_bump(sat_solver2* s, int v) {
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s->activity[v] += s->var_inc;
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if (s->activity[v] > 1e100)
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act_var_rescale(s);
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if (s->orderpos[v] != -1)
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order_update(s,v);
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}
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static inline void act_clause_bump(sat_solver2* s, satset*c) {
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float * claActs = (float *)veci_begin(&s->claActs);
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assert( c->Id < veci_size(&s->claActs) );
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claActs[c->Id] += s->cla_inc;
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if (claActs[c->Id] > (float)1e20)
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act_clause_rescale(s);
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}
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static inline void act_var_decay(sat_solver2* s) { s->var_inc *= s->var_decay; }
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static inline void act_clause_decay(sat_solver2* s) { s->cla_inc *= s->cla_decay; }
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#else
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static inline void act_var_rescale(sat_solver2* s) {
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unsigned* activity = s->activity;
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int i;
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for (i = 0; i < s->size; i++)
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activity[i] >>= 19;
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s->var_inc >>= 19;
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s->var_inc = Abc_MaxInt( s->var_inc, (1<<4) );
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}
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static inline void act_clause_rescale(sat_solver2* s) {
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static int Total = 0;
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int i, clk = clock();
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unsigned * claActs = (unsigned *)veci_begin(&s->claActs);
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for (i = 1; i < veci_size(&s->claActs); i++)
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claActs[i] >>= 14;
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s->cla_inc >>= 14;
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s->cla_inc = Abc_MaxInt( s->cla_inc, (1<<10) );
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printf( "Rescaling... Cla inc = %5d Conf = %10d ", s->cla_inc, s->stats.conflicts );
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Total += clock() - clk;
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Abc_PrintTime( 1, "Time", Total );
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}
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static inline void act_var_bump(sat_solver2* s, int v) {
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s->activity[v] += s->var_inc;
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if (s->activity[v] & 0x80000000)
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act_var_rescale(s);
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if (s->orderpos[v] != -1)
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order_update(s,v);
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}
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static inline void act_clause_bump(sat_solver2* s, satset*c) {
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unsigned * claActs = (unsigned *)veci_begin(&s->claActs);
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assert( c->Id > 0 && c->Id < veci_size(&s->claActs) );
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claActs[c->Id] += s->cla_inc;
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if (claActs[c->Id] & 0x80000000)
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act_clause_rescale(s);
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}
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static inline void act_var_decay(sat_solver2* s) { s->var_inc += (s->var_inc >> 4); }
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static inline void act_clause_decay(sat_solver2* s) { s->cla_inc += (s->cla_inc >> 10); }
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#endif
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//=================================================================================================
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// Clause functions:
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static int clause_new(sat_solver2* s, lit* begin, lit* end, int learnt, int proof_id)
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{
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satset* c;
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int i, Cid, nLits = end - begin;
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assert(nLits < 1 || begin[0] >= 0);
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assert(nLits < 2 || begin[1] >= 0);
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assert(nLits < 1 || lit_var(begin[0]) < s->size);
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assert(nLits < 2 || lit_var(begin[1]) < s->size);
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// add memory if needed
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if ( veci_size(&s->clauses) + clause_size(nLits) > s->clauses.cap )
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{
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int nMemAlloc = s->clauses.cap ? 2 * s->clauses.cap : (1 << 20);
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s->clauses.ptr = ABC_REALLOC( int, veci_begin(&s->clauses), nMemAlloc );
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memset( veci_begin(&s->clauses) + s->clauses.cap, 0, sizeof(int) * (nMemAlloc - s->clauses.cap) );
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// printf( "Reallocing from %d to %d...\n", s->clauses.cap, nMemAlloc );
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s->clauses.cap = nMemAlloc;
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s->clauses.size = Abc_MaxInt( veci_size(&s->clauses), 2 );
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}
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// create clause
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c = (satset*)(veci_begin(&s->clauses) + veci_size(&s->clauses));
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c->learnt = learnt;
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c->nLits = nLits;
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for (i = 0; i < nLits; i++)
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c->pLits[i] = begin[i];
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// assign clause ID
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if ( learnt )
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{
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s->stats.learnts++;
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s->stats.learnts_literals += nLits;
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c->Id = s->stats.learnts;
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assert( c->Id == veci_size(&s->claActs) );
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veci_push(&s->claActs, 0);
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if ( proof_id )
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veci_push(&s->claProofs, proof_id);
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if ( nLits > 2 )
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act_clause_bump( s,c );
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}
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else
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{
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s->stats.clauses++;
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s->stats.clauses_literals += nLits;
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|
c->Id = s->stats.clauses;
|
|
}
|
|
|
|
// extend storage
|
|
Cid = veci_size(&s->clauses);
|
|
s->clauses.size += clause_size(nLits);
|
|
assert( veci_size(&s->clauses) <= s->clauses.cap );
|
|
assert(((ABC_PTRUINT_T)c & 3) == 0);
|
|
|
|
// remember the last one and first learnt
|
|
s->fLastConfId = Cid;
|
|
if ( learnt && s->iFirstLearnt == -1 )
|
|
s->iFirstLearnt = Cid;
|
|
|
|
// watch the clause
|
|
if ( nLits > 1 ){
|
|
veci_push(solver2_wlist(s,lit_neg(begin[0])),Cid);
|
|
veci_push(solver2_wlist(s,lit_neg(begin[1])),Cid);
|
|
}
|
|
return Cid;
|
|
}
|
|
|
|
//=================================================================================================
|
|
// Minor (solver) functions:
|
|
|
|
static inline int solver2_enqueue(sat_solver2* s, lit l, int from)
|
|
{
|
|
int v = lit_var(l);
|
|
#ifdef VERBOSEDEBUG
|
|
printf(L_IND"solver2_enqueue("L_LIT")\n", L_ind, L_lit(l));
|
|
#endif
|
|
if (var_value(s, v) != varX)
|
|
return var_value(s, v) == lit_sign(l);
|
|
else
|
|
{ // New fact -- store it.
|
|
#ifdef VERBOSEDEBUG
|
|
printf(L_IND"bind("L_LIT")\n", L_ind, L_lit(l));
|
|
#endif
|
|
var_set_value( s, v, lit_sign(l) );
|
|
var_set_level( s, v, solver2_dlevel(s) );
|
|
/*
|
|
if ( s->units && s->units[v] != 0 )
|
|
{
|
|
assert( solver2_dlevel(s) == 0 );
|
|
// assert( from == 0 );
|
|
if ( from )
|
|
printf( "." );
|
|
}
|
|
*/
|
|
s->reasons[v] = from; // = from << 1;
|
|
s->trail[s->qtail++] = l;
|
|
order_assigned(s, v);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
static inline int solver2_assume(sat_solver2* s, lit l)
|
|
{
|
|
assert(s->qtail == s->qhead);
|
|
assert(var_value(s, lit_var(l)) == varX);
|
|
#ifdef VERBOSEDEBUG
|
|
printf(L_IND"solver2_assume("L_LIT")\n", L_ind, L_lit(l));
|
|
#endif
|
|
veci_push(&s->trail_lim,s->qtail);
|
|
return solver2_enqueue(s,l,0);
|
|
}
|
|
|
|
static void solver2_canceluntil(sat_solver2* s, int level) {
|
|
lit* trail;
|
|
int bound;
|
|
int lastLev;
|
|
int c, x;
|
|
|
|
if (solver2_dlevel(s) <= level)
|
|
return;
|
|
|
|
trail = s->trail;
|
|
bound = (veci_begin(&s->trail_lim))[level];
|
|
lastLev = (veci_begin(&s->trail_lim))[veci_size(&s->trail_lim)-1];
|
|
|
|
for (c = s->qtail-1; c >= bound; c--)
|
|
{
|
|
x = lit_var(trail[c]);
|
|
var_set_value(s, x, varX);
|
|
s->reasons[x] = 0;
|
|
if ( c < lastLev )
|
|
var_set_polar(s, x, !lit_sign(trail[c]));
|
|
}
|
|
|
|
for (c = s->qhead-1; c >= bound; c--)
|
|
order_unassigned(s,lit_var(trail[c]));
|
|
|
|
s->qhead = s->qtail = bound;
|
|
veci_resize(&s->trail_lim,level);
|
|
}
|
|
|
|
|
|
static void solver2_record(sat_solver2* s, veci* cls, int proof_id)
|
|
{
|
|
lit* begin = veci_begin(cls);
|
|
lit* end = begin + veci_size(cls);
|
|
int Cid = clause_new(s,begin,end,1, proof_id);
|
|
assert(veci_size(cls) > 0);
|
|
if ( veci_size(cls) == 1 )
|
|
{
|
|
if ( s->fProofLogging )
|
|
var_set_unit_clause(s, lit_var(begin[0]), Cid);
|
|
Cid = 0;
|
|
}
|
|
solver2_enqueue(s, begin[0], Cid);
|
|
}
|
|
|
|
|
|
static double solver2_progress(sat_solver2* s)
|
|
{
|
|
int i;
|
|
double progress = 0.0, F = 1.0 / s->size;
|
|
for (i = 0; i < s->size; i++)
|
|
if (var_value(s, i) != varX)
|
|
progress += pow(F, var_level(s, i));
|
|
return progress / s->size;
|
|
}
|
|
|
|
//=================================================================================================
|
|
// Major methods:
|
|
|
|
/*_________________________________________________________________________________________________
|
|
|
|
|
| analyzeFinal : (p : Lit) -> [void]
|
|
|
|
|
| Description:
|
|
| Specialized analysis procedure to express the final conflict in terms of assumptions.
|
|
| Calculates the (possibly empty) set of assumptions that led to the assignment of 'p', and
|
|
| stores the result in 'out_conflict'.
|
|
|________________________________________________________________________________________________@*/
|
|
/*
|
|
void Solver::analyzeFinal(satset* confl, bool skip_first)
|
|
{
|
|
// -- NOTE! This code is relatively untested. Please report bugs!
|
|
conflict.clear();
|
|
if (root_level == 0) return;
|
|
|
|
vec<char>& seen = analyze_seen;
|
|
for (int i = skip_first ? 1 : 0; i < confl->size(); i++){
|
|
Var x = var((*confl)[i]);
|
|
if (level[x] > 0)
|
|
seen[x] = 1;
|
|
}
|
|
|
|
int start = (root_level >= trail_lim.size()) ? trail.size()-1 : trail_lim[root_level];
|
|
for (int i = start; i >= trail_lim[0]; i--){
|
|
Var x = var(trail[i]);
|
|
if (seen[x]){
|
|
GClause r = reason[x];
|
|
if (r == GClause_NULL){
|
|
assert(level[x] > 0);
|
|
conflict.push(~trail[i]);
|
|
}else{
|
|
if (r.isLit()){
|
|
Lit p = r.lit();
|
|
if (level[var(p)] > 0)
|
|
seen[var(p)] = 1;
|
|
}else{
|
|
Clause& c = *r.clause();
|
|
for (int j = 1; j < c.size(); j++)
|
|
if (level[var(c[j])] > 0)
|
|
seen[var(c[j])] = 1;
|
|
}
|
|
}
|
|
seen[x] = 0;
|
|
}
|
|
}
|
|
}
|
|
*/
|
|
|
|
#ifdef SAT_USE_ANALYZE_FINAL
|
|
|
|
static int solver2_analyze_final(sat_solver2* s, satset* conf, int skip_first)
|
|
{
|
|
int i, j, x;//, start;
|
|
veci_resize(&s->conf_final,0);
|
|
if ( s->root_level == 0 )
|
|
return -1;
|
|
proof_chain_start( s, conf );
|
|
assert( veci_size(&s->tagged) == 0 );
|
|
for ( i = skip_first; i < (int)conf->nLits; i++ )
|
|
{
|
|
x = lit_var(conf->pLits[i]);
|
|
if ( var_level(s,x) )
|
|
var_set_tag(s, x, 1);
|
|
else
|
|
proof_chain_resolve( s, NULL, x );
|
|
}
|
|
assert( s->root_level >= veci_size(&s->trail_lim) );
|
|
// start = (s->root_level >= veci_size(&s->trail_lim))? s->qtail-1 : (veci_begin(&s->trail_lim))[s->root_level];
|
|
for (i = s->qtail-1; i >= (veci_begin(&s->trail_lim))[0]; i--){
|
|
x = lit_var(s->trail[i]);
|
|
if (var_tag(s,x)){
|
|
satset* c = get_clause(s, var_reason(s,x));
|
|
if (c){
|
|
proof_chain_resolve( s, c, x );
|
|
for (j = 1; j < (int)c->nLits; j++) {
|
|
x = lit_var(c->pLits[j]);
|
|
if ( var_level(s,x) )
|
|
var_set_tag(s, x, 1);
|
|
else
|
|
proof_chain_resolve( s, NULL, x );
|
|
}
|
|
}else {
|
|
assert( var_level(s,x) );
|
|
veci_push(&s->conf_final,lit_neg(s->trail[i]));
|
|
}
|
|
}
|
|
}
|
|
solver2_clear_tags(s,0);
|
|
return proof_chain_stop( s );
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
static int solver2_lit_removable_rec(sat_solver2* s, int v)
|
|
{
|
|
// tag[0]: True if original conflict clause literal.
|
|
// tag[1]: Processed by this procedure
|
|
// tag[2]: 0=non-removable, 1=removable
|
|
|
|
satset* c;
|
|
int i, x;
|
|
|
|
// skip visited
|
|
if (var_tag(s,v) & 2)
|
|
return (var_tag(s,v) & 4) > 0;
|
|
|
|
// skip decisions on a wrong level
|
|
c = get_clause(s, var_reason(s,v));
|
|
if ( c == NULL ){
|
|
var_add_tag(s,v,2);
|
|
return 0;
|
|
}
|
|
|
|
for ( i = 1; i < (int)c->nLits; i++ ){
|
|
x = lit_var(c->pLits[i]);
|
|
if (var_tag(s,x) & 1)
|
|
solver2_lit_removable_rec(s, x);
|
|
else{
|
|
if (var_level(s,x) == 0 || var_tag(s,x) == 6) continue; // -- 'x' checked before, found to be removable (or belongs to the toplevel)
|
|
if (var_tag(s,x) == 2 || !var_lev_mark(s,x) || !solver2_lit_removable_rec(s, x))
|
|
{ // -- 'x' checked before, found NOT to be removable, or it belongs to a wrong level, or cannot be removed
|
|
var_add_tag(s,v,2);
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
// if (pfl && visit[p0] & 1){
|
|
// result.push(p0); }
|
|
var_add_tag(s,v,6);
|
|
return 1;
|
|
}
|
|
|
|
static int solver2_lit_removable(sat_solver2* s, int x)
|
|
{
|
|
satset* c;
|
|
int i, top;
|
|
if ( !var_reason(s,x) )
|
|
return 0;
|
|
if ( var_tag(s,x) & 2 )
|
|
{
|
|
assert( var_tag(s,x) & 1 );
|
|
return 1;
|
|
}
|
|
top = veci_size(&s->tagged);
|
|
veci_resize(&s->stack,0);
|
|
veci_push(&s->stack, x << 1);
|
|
while (veci_size(&s->stack))
|
|
{
|
|
x = veci_pop(&s->stack);
|
|
if ( s->fProofLogging ){
|
|
if ( x & 1 ){
|
|
if ( var_tag(s,x >> 1) & 1 )
|
|
veci_push(&s->min_lit_order, x >> 1 );
|
|
continue;
|
|
}
|
|
veci_push(&s->stack, x ^ 1 );
|
|
}
|
|
x >>= 1;
|
|
c = get_clause(s, var_reason(s,x));
|
|
for (i = 1; i < (int)c->nLits; i++){
|
|
x = lit_var(c->pLits[i]);
|
|
if (var_tag(s,x) || !var_level(s,x))
|
|
continue;
|
|
if (!var_reason(s,x) || !var_lev_mark(s,x)){
|
|
solver2_clear_tags(s, top);
|
|
return 0;
|
|
}
|
|
veci_push(&s->stack, x << 1);
|
|
var_set_tag(s, x, 2);
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void solver2_logging_order(sat_solver2* s, int x)
|
|
{
|
|
satset* c;
|
|
int i;
|
|
if ( (var_tag(s,x) & 4) )
|
|
return;
|
|
var_add_tag(s, x, 4);
|
|
veci_resize(&s->stack,0);
|
|
veci_push(&s->stack,x << 1);
|
|
while (veci_size(&s->stack))
|
|
{
|
|
x = veci_pop(&s->stack);
|
|
if ( x & 1 ){
|
|
veci_push(&s->min_step_order, x >> 1 );
|
|
continue;
|
|
}
|
|
veci_push(&s->stack, x ^ 1 );
|
|
x >>= 1;
|
|
c = get_clause(s, var_reason(s,x));
|
|
// if ( !c )
|
|
// printf( "solver2_logging_order(): Error in conflict analysis!!!\n" );
|
|
for (i = 1; i < (int)c->nLits; i++){
|
|
x = lit_var(c->pLits[i]);
|
|
if ( !var_level(s,x) || (var_tag(s,x) & 1) )
|
|
continue;
|
|
veci_push(&s->stack, x << 1);
|
|
var_add_tag(s, x, 4);
|
|
}
|
|
}
|
|
}
|
|
|
|
static int solver2_analyze(sat_solver2* s, satset* c, veci* learnt)
|
|
{
|
|
int cnt = 0;
|
|
lit p = lit_Undef;
|
|
int x, ind = s->qtail-1;
|
|
int proof_id = 0;
|
|
lit* lits,* vars, i, j, k;
|
|
assert( veci_size(&s->tagged) == 0 );
|
|
// tag[0] - visited by conflict analysis (afterwards: literals of the learned clause)
|
|
// tag[1] - visited by solver2_lit_removable() with success
|
|
// tag[2] - visited by solver2_logging_order()
|
|
|
|
proof_chain_start( s, c );
|
|
veci_push(learnt,lit_Undef);
|
|
while ( 1 ){
|
|
assert(c != 0);
|
|
if (c->learnt)
|
|
act_clause_bump(s,c);
|
|
for ( j = (int)(p != lit_Undef); j < (int)c->nLits; j++){
|
|
x = lit_var(c->pLits[j]);
|
|
assert(x >= 0 && x < s->size);
|
|
if ( var_tag(s, x) )
|
|
continue;
|
|
if ( var_level(s,x) == 0 )
|
|
{
|
|
proof_chain_resolve( s, NULL, x );
|
|
continue;
|
|
}
|
|
var_set_tag(s, x, 1);
|
|
act_var_bump(s,x);
|
|
if (var_level(s,x) == solver2_dlevel(s))
|
|
cnt++;
|
|
else
|
|
veci_push(learnt,c->pLits[j]);
|
|
}
|
|
|
|
while (!var_tag(s, lit_var(s->trail[ind--])));
|
|
|
|
p = s->trail[ind+1];
|
|
c = get_clause(s, lit_reason(s,p));
|
|
cnt--;
|
|
if ( cnt == 0 )
|
|
break;
|
|
proof_chain_resolve( s, c, lit_var(p) );
|
|
}
|
|
*veci_begin(learnt) = lit_neg(p);
|
|
|
|
// mark levels
|
|
assert( veci_size(&s->mark_levels) == 0 );
|
|
lits = veci_begin(learnt);
|
|
for (i = 1; i < veci_size(learnt); i++)
|
|
var_lev_set_mark(s, lit_var(lits[i]));
|
|
|
|
// simplify (full)
|
|
veci_resize(&s->min_lit_order, 0);
|
|
for (i = j = 1; i < veci_size(learnt); i++){
|
|
// if (!solver2_lit_removable_rec(s,lit_var(lits[i]))) // changed to vars!!!
|
|
if (!solver2_lit_removable( s,lit_var(lits[i])) )
|
|
lits[j++] = lits[i];
|
|
}
|
|
|
|
// record the proof
|
|
if ( s->fProofLogging )
|
|
{
|
|
// collect additional clauses to resolve
|
|
veci_resize(&s->min_step_order, 0);
|
|
vars = veci_begin(&s->min_lit_order);
|
|
for (i = 0; i < veci_size(&s->min_lit_order); i++)
|
|
solver2_logging_order( s, vars[i] );
|
|
|
|
// add them in the reverse order
|
|
vars = veci_begin(&s->min_step_order);
|
|
for (i = veci_size(&s->min_step_order); i > 0; ) { i--;
|
|
c = get_clause(s, var_reason(s,vars[i]));
|
|
proof_chain_resolve( s, c, vars[i] );
|
|
for ( k = 1; k < (int)c->nLits; k++ )
|
|
{
|
|
x = lit_var(c->pLits[k]);
|
|
if ( var_level(s,x) == 0 )
|
|
proof_chain_resolve( s, NULL, x );
|
|
}
|
|
}
|
|
proof_id = proof_chain_stop( s );
|
|
}
|
|
|
|
// unmark levels
|
|
solver2_clear_marks( s );
|
|
|
|
// update size of learnt + statistics
|
|
s->stats.max_literals += veci_size(learnt);
|
|
veci_resize(learnt,j);
|
|
s->stats.tot_literals += j;
|
|
|
|
// clear tags
|
|
solver2_clear_tags(s,0);
|
|
|
|
#ifdef DEBUG
|
|
for (i = 0; i < s->size; i++)
|
|
assert(!var_tag(s, i));
|
|
#endif
|
|
|
|
#ifdef VERBOSEDEBUG
|
|
printf(L_IND"Learnt {", L_ind);
|
|
for (i = 0; i < veci_size(learnt); i++) printf(" "L_LIT, L_lit(lits[i]));
|
|
#endif
|
|
if (veci_size(learnt) > 1){
|
|
lit tmp;
|
|
int max_i = 1;
|
|
int max = var_level(s, lit_var(lits[1]));
|
|
for (i = 2; i < veci_size(learnt); i++)
|
|
if (max < var_level(s, lit_var(lits[i]))) {
|
|
max = var_level(s, lit_var(lits[i]));
|
|
max_i = i;
|
|
}
|
|
|
|
tmp = lits[1];
|
|
lits[1] = lits[max_i];
|
|
lits[max_i] = tmp;
|
|
}
|
|
#ifdef VERBOSEDEBUG
|
|
{
|
|
int lev = veci_size(learnt) > 1 ? var_level(s, lit_var(lits[1])) : 0;
|
|
printf(" } at level %d\n", lev);
|
|
}
|
|
#endif
|
|
return proof_id;
|
|
}
|
|
|
|
satset* solver2_propagate(sat_solver2* s)
|
|
{
|
|
satset* c, * confl = NULL;
|
|
veci* ws;
|
|
lit* lits, false_lit, p, * stop, * k;
|
|
cla* begin,* end, *i, *j;
|
|
|
|
while (confl == 0 && s->qtail - s->qhead > 0){
|
|
|
|
p = s->trail[s->qhead++];
|
|
ws = solver2_wlist(s,p);
|
|
begin = (cla*)veci_begin(ws);
|
|
end = begin + veci_size(ws);
|
|
|
|
s->stats.propagations++;
|
|
s->simpdb_props--;
|
|
|
|
for (i = j = begin; i < end; ){
|
|
c = get_clause(s,*i);
|
|
lits = c->pLits;
|
|
|
|
// Make sure the false literal is data[1]:
|
|
false_lit = lit_neg(p);
|
|
if (lits[0] == false_lit){
|
|
lits[0] = lits[1];
|
|
lits[1] = false_lit;
|
|
}
|
|
assert(lits[1] == false_lit);
|
|
|
|
// If 0th watch is true, then clause is already satisfied.
|
|
if (var_value(s, lit_var(lits[0])) == lit_sign(lits[0]))
|
|
*j++ = *i;
|
|
else{
|
|
// Look for new watch:
|
|
stop = lits + c->nLits;
|
|
for (k = lits + 2; k < stop; k++){
|
|
if (var_value(s, lit_var(*k)) != !lit_sign(*k)){
|
|
lits[1] = *k;
|
|
*k = false_lit;
|
|
veci_push(solver2_wlist(s,lit_neg(lits[1])),*i);
|
|
goto WatchFound; }
|
|
}
|
|
|
|
// Did not find watch -- clause is unit under assignment:
|
|
if (s->fProofLogging && solver2_dlevel(s) == 0){
|
|
int k, proof_id, Cid, Var = lit_var(lits[0]);
|
|
int fLitIsFalse = (var_value(s, Var) == !lit_sign(lits[0]));
|
|
// Log production of top-level unit clause:
|
|
proof_chain_start( s, c );
|
|
for ( k = 1; k < (int)c->nLits; k++ )
|
|
{
|
|
int x = lit_var(c->pLits[k]);
|
|
assert( var_level(s, x) == 0 );
|
|
proof_chain_resolve( s, NULL, x );
|
|
}
|
|
proof_id = proof_chain_stop( s );
|
|
// get a new clause
|
|
Cid = clause_new( s, lits, lits + 1, 1, proof_id );
|
|
assert( (var_unit_clause(s, Var) == NULL) != fLitIsFalse );
|
|
// if variable already has unit clause, it must be with the other polarity
|
|
// in this case, we should derive the empty clause here
|
|
if ( var_unit_clause(s, Var) == NULL )
|
|
var_set_unit_clause(s, Var, Cid);
|
|
else{
|
|
// Empty clause derived:
|
|
proof_chain_start( s, get_clause(s,Cid) );
|
|
proof_chain_resolve( s, NULL, Var );
|
|
proof_id = proof_chain_stop( s );
|
|
clause_new( s, lits, lits, 1, proof_id );
|
|
}
|
|
}
|
|
|
|
*j++ = *i;
|
|
// Clause is unit under assignment:
|
|
if (!solver2_enqueue(s,lits[0], *i)){
|
|
confl = get_clause(s,*i++);
|
|
// Copy the remaining watches:
|
|
while (i < end)
|
|
*j++ = *i++;
|
|
}
|
|
}
|
|
WatchFound: i++;
|
|
}
|
|
s->stats.inspects += j - (int*)veci_begin(ws);
|
|
veci_resize(ws,j - (int*)veci_begin(ws));
|
|
}
|
|
|
|
return confl;
|
|
}
|
|
|
|
|
|
|
|
static void clause_remove(sat_solver2* s, satset* c)
|
|
{
|
|
assert(lit_neg(c->pLits[0]) < s->size*2);
|
|
assert(lit_neg(c->pLits[1]) < s->size*2);
|
|
|
|
veci_remove(solver2_wlist(s,lit_neg(c->pLits[0])),clause_id(s,c));
|
|
veci_remove(solver2_wlist(s,lit_neg(c->pLits[1])),clause_id(s,c));
|
|
|
|
if (c->learnt){
|
|
s->stats.learnts--;
|
|
s->stats.learnts_literals -= c->nLits;
|
|
}else{
|
|
s->stats.clauses--;
|
|
s->stats.clauses_literals -= c->nLits;
|
|
}
|
|
}
|
|
|
|
|
|
static lbool clause_simplify(sat_solver2* s, satset* c)
|
|
{
|
|
int i;
|
|
assert(solver2_dlevel(s) == 0);
|
|
for (i = 0; i < (int)c->nLits; i++){
|
|
if (var_value(s, lit_var(c->pLits[i])) == lit_sign(c->pLits[i]))
|
|
return l_True;
|
|
}
|
|
return l_False;
|
|
}
|
|
|
|
int sat_solver2_simplify(sat_solver2* s)
|
|
{
|
|
// int type;
|
|
int Counter = 0;
|
|
assert(solver2_dlevel(s) == 0);
|
|
if (solver2_propagate(s) != 0)
|
|
return false;
|
|
if (s->qhead == s->simpdb_assigns || s->simpdb_props > 0)
|
|
return true;
|
|
/*
|
|
for (type = 0; type < 2; type++){
|
|
veci* cs = type ? &s->learnts : &s->clauses;
|
|
int* cls = (int*)veci_begin(cs);
|
|
int i, j;
|
|
for (j = i = 0; i < veci_size(cs); i++){
|
|
satset* c = get_clause(s,cls[i]);
|
|
if (lit_reason(s,c->pLits[0]) != cls[i] &&
|
|
clause_simplify(s,c) == l_True)
|
|
clause_remove(s,c), Counter++;
|
|
else
|
|
cls[j++] = cls[i];
|
|
}
|
|
veci_resize(cs,j);
|
|
}
|
|
*/
|
|
//printf( "Simplification removed %d clauses (out of %d)...\n", Counter, s->stats.clauses );
|
|
s->simpdb_assigns = s->qhead;
|
|
// (shouldn't depend on 'stats' really, but it will do for now)
|
|
s->simpdb_props = (int)(s->stats.clauses_literals + s->stats.learnts_literals);
|
|
return true;
|
|
}
|
|
|
|
void solver2_reducedb(sat_solver2* s)
|
|
{
|
|
/*
|
|
satset* c;
|
|
cla Cid;
|
|
int clk = clock();
|
|
|
|
// sort the clauses by activity
|
|
int nLearnts = veci_size(&s->claActs) - 1;
|
|
extern int * Abc_SortCost( int * pCosts, int nSize );
|
|
int * pPerm, * pCosts = veci_begin(&s->claActs);
|
|
pPerm = Abc_SortCost( pCosts, veci_size(&s->claActs) );
|
|
assert( pCosts[pPerm[1]] <= pCosts[pPerm[veci_size(&s->claActs)-1]] );
|
|
|
|
// mark clauses to be removed
|
|
{
|
|
double extra_limD = (double)s->cla_inc / nLearnts; // Remove any clause below this activity
|
|
unsigned extra_lim = (extra_limD < 1.0) ? 1 : (int)extra_limD;
|
|
unsigned * pActs = (unsigned *)veci_begin(&s->claActs);
|
|
int k = 1, Counter = 0;
|
|
sat_solver_foreach_learnt( s, c, Cid )
|
|
{
|
|
assert( c->Id == k );
|
|
c->mark = 0;
|
|
if ( c->nLits > 2 && lit_reason(s,c->pLits[0]) != Cid && (k < nLearnts/2 || pActs[k] < extra_lim) )
|
|
{
|
|
c->mark = 1;
|
|
Counter++;
|
|
}
|
|
k++;
|
|
}
|
|
printf( "ReduceDB removed %10d clauses (out of %10d)... Cutoff = %8d ", Counter, nLearnts, extra_lim );
|
|
Abc_PrintTime( 1, "Time", clock() - clk );
|
|
}
|
|
ABC_FREE( pPerm );
|
|
*/
|
|
}
|
|
|
|
|
|
static lbool solver2_search(sat_solver2* s, ABC_INT64_T nof_conflicts, ABC_INT64_T * nof_learnts)
|
|
{
|
|
double random_var_freq = s->fNotUseRandom ? 0.0 : 0.02;
|
|
|
|
ABC_INT64_T conflictC = 0;
|
|
veci learnt_clause;
|
|
int proof_id;
|
|
|
|
assert(s->root_level == solver2_dlevel(s));
|
|
|
|
s->stats.starts++;
|
|
veci_resize(&s->model,0);
|
|
veci_new(&learnt_clause);
|
|
|
|
for (;;){
|
|
satset* confl = solver2_propagate(s);
|
|
if (confl != 0){
|
|
// CONFLICT
|
|
int blevel;
|
|
|
|
#ifdef VERBOSEDEBUG
|
|
printf(L_IND"**CONFLICT**\n", L_ind);
|
|
#endif
|
|
s->stats.conflicts++; conflictC++;
|
|
if (solver2_dlevel(s) <= s->root_level){
|
|
#ifdef SAT_USE_ANALYZE_FINAL
|
|
proof_id = solver2_analyze_final(s, confl, 0);
|
|
if ( proof_id > 0 )
|
|
solver2_record(s,&s->conf_final, proof_id);
|
|
#endif
|
|
veci_delete(&learnt_clause);
|
|
return l_False;
|
|
}
|
|
|
|
veci_resize(&learnt_clause,0);
|
|
proof_id = solver2_analyze(s, confl, &learnt_clause);
|
|
blevel = veci_size(&learnt_clause) > 1 ? var_level(s, lit_var(veci_begin(&learnt_clause)[1])) : s->root_level;
|
|
blevel = s->root_level > blevel ? s->root_level : blevel;
|
|
solver2_canceluntil(s,blevel);
|
|
solver2_record(s,&learnt_clause, proof_id);
|
|
#ifdef SAT_USE_ANALYZE_FINAL
|
|
// if (learnt_clause.size() == 1) level[var(learnt_clause[0])] = 0;
|
|
// (this is ugly (but needed for 'analyzeFinal()') -- in future versions, we will backtrack past the 'root_level' and redo the assumptions)
|
|
if ( learnt_clause.size == 1 )
|
|
var_set_level( s, lit_var(learnt_clause.ptr[0]), 0 );
|
|
#endif
|
|
act_var_decay(s);
|
|
act_clause_decay(s);
|
|
|
|
}else{
|
|
// NO CONFLICT
|
|
int next;
|
|
|
|
if (nof_conflicts >= 0 && conflictC >= nof_conflicts){
|
|
// Reached bound on number of conflicts:
|
|
s->progress_estimate = solver2_progress(s);
|
|
solver2_canceluntil(s,s->root_level);
|
|
veci_delete(&learnt_clause);
|
|
return l_Undef; }
|
|
|
|
if ( (s->nConfLimit && s->stats.conflicts > s->nConfLimit) ||
|
|
// (s->nInsLimit && s->stats.inspects > s->nInsLimit) )
|
|
(s->nInsLimit && s->stats.propagations > s->nInsLimit) )
|
|
{
|
|
// Reached bound on number of conflicts:
|
|
s->progress_estimate = solver2_progress(s);
|
|
solver2_canceluntil(s,s->root_level);
|
|
veci_delete(&learnt_clause);
|
|
return l_Undef;
|
|
}
|
|
|
|
// if (solver2_dlevel(s) == 0 && !s->fSkipSimplify)
|
|
// Simplify the set of problem clauses:
|
|
// sat_solver2_simplify(s);
|
|
|
|
if (*nof_learnts >= 0 && s->stats.learnts - s->qtail >= *nof_learnts)
|
|
{
|
|
// Reduce the set of learnt clauses:
|
|
solver2_reducedb(s);
|
|
*nof_learnts = *nof_learnts * 11 / 10; //*= 1.1;
|
|
}
|
|
|
|
// New variable decision:
|
|
s->stats.decisions++;
|
|
next = order_select(s,(float)random_var_freq);
|
|
|
|
if (next == var_Undef){
|
|
// Model found:
|
|
int i;
|
|
veci_resize(&s->model, 0);
|
|
for (i = 0; i < s->size; i++)
|
|
veci_push( &s->model, var_value(s,i)==var1 ? l_True : l_False );
|
|
solver2_canceluntil(s,s->root_level);
|
|
veci_delete(&learnt_clause);
|
|
|
|
/*
|
|
veci apa; veci_new(&apa);
|
|
for (i = 0; i < s->size; i++)
|
|
veci_push(&apa,(int)(s->model.ptr[i] == l_True ? toLit(i) : lit_neg(toLit(i))));
|
|
printf("model: "); printlits((lit*)apa.ptr, (lit*)apa.ptr + veci_size(&apa)); printf("\n");
|
|
veci_delete(&apa);
|
|
*/
|
|
|
|
return l_True;
|
|
}
|
|
|
|
if ( var_polar(s, next) ) // positive polarity
|
|
solver2_assume(s,toLit(next));
|
|
else
|
|
solver2_assume(s,lit_neg(toLit(next)));
|
|
}
|
|
}
|
|
|
|
return l_Undef; // cannot happen
|
|
}
|
|
|
|
//=================================================================================================
|
|
// External solver functions:
|
|
|
|
sat_solver2* sat_solver2_new(void)
|
|
{
|
|
sat_solver2* s = (sat_solver2 *)ABC_CALLOC( char, sizeof(sat_solver2) );
|
|
|
|
// initialize vectors
|
|
veci_new(&s->order);
|
|
veci_new(&s->trail_lim);
|
|
veci_new(&s->tagged);
|
|
veci_new(&s->stack);
|
|
veci_new(&s->model);
|
|
veci_new(&s->temp_clause);
|
|
veci_new(&s->conf_final);
|
|
veci_new(&s->mark_levels);
|
|
veci_new(&s->min_lit_order);
|
|
veci_new(&s->min_step_order);
|
|
veci_new(&s->proof_clas); veci_push(&s->proof_clas, -1);
|
|
veci_new(&s->proof_vars); veci_push(&s->proof_vars, -1);
|
|
veci_new(&s->claActs); veci_push(&s->claActs, -1);
|
|
veci_new(&s->claProofs); veci_push(&s->claProofs, -1);
|
|
|
|
// initialize other
|
|
s->iFirstLearnt = -1; // the first learnt clause
|
|
s->fLastConfId = -1; // the last learnt clause
|
|
#ifdef USE_FLOAT_ACTIVITY
|
|
s->var_inc = 1;
|
|
s->cla_inc = 1;
|
|
s->var_decay = (float)(1 / 0.95 );
|
|
s->cla_decay = (float)(1 / 0.999 );
|
|
#else
|
|
s->var_inc = (1 << 5);
|
|
s->cla_inc = (1 << 11);
|
|
#endif
|
|
s->random_seed = 91648253;
|
|
|
|
#ifdef SAT_USE_PROOF_LOGGING
|
|
s->fProofLogging = 1;
|
|
#else
|
|
s->fProofLogging = 0;
|
|
#endif
|
|
|
|
// prealloc some arrays
|
|
if ( s->fProofLogging )
|
|
{
|
|
s->proof_clas.cap = (1 << 20);
|
|
s->proof_clas.ptr = ABC_ALLOC( int, s->proof_clas.cap );
|
|
s->proof_vars.cap = (1 << 20);
|
|
s->proof_vars.ptr = ABC_ALLOC( int, s->proof_clas.cap );
|
|
}
|
|
return s;
|
|
}
|
|
|
|
|
|
void sat_solver2_setnvars(sat_solver2* s,int n)
|
|
{
|
|
int var;
|
|
|
|
if (s->cap < n){
|
|
|
|
while (s->cap < n) s->cap = s->cap*2+1;
|
|
|
|
s->wlists = ABC_REALLOC(veci, s->wlists, s->cap*2);
|
|
s->vi = ABC_REALLOC(varinfo, s->vi, s->cap);
|
|
s->trail = ABC_REALLOC(lit, s->trail, s->cap);
|
|
s->orderpos = ABC_REALLOC(int, s->orderpos, s->cap);
|
|
s->reasons = ABC_REALLOC(cla, s->reasons, s->cap);
|
|
if ( s->fProofLogging )
|
|
s->units = ABC_REALLOC(cla, s->units, s->cap);
|
|
#ifdef USE_FLOAT_ACTIVITY
|
|
s->activity = ABC_REALLOC(double, s->activity, s->cap);
|
|
#else
|
|
s->activity = ABC_REALLOC(unsigned, s->activity, s->cap);
|
|
#endif
|
|
}
|
|
|
|
for (var = s->size; var < n; var++){
|
|
veci_new(&s->wlists[2*var]);
|
|
veci_new(&s->wlists[2*var+1]);
|
|
*((int*)s->vi + var) = 0; s->vi[var].val = varX;
|
|
s->orderpos[var] = veci_size(&s->order);
|
|
s->reasons [var] = 0;
|
|
if ( s->fProofLogging )
|
|
s->units [var] = 0;
|
|
s->activity[var] = (1<<10);
|
|
// does not hold because variables enqueued at top level will not be reinserted in the heap
|
|
// assert(veci_size(&s->order) == var);
|
|
veci_push(&s->order,var);
|
|
order_update(s, var);
|
|
}
|
|
s->size = n > s->size ? n : s->size;
|
|
}
|
|
|
|
void sat_solver2_delete(sat_solver2* s)
|
|
{
|
|
// report statistics
|
|
assert( veci_size(&s->proof_clas) == veci_size(&s->proof_vars) );
|
|
printf( "Used %6.2f Mb for proof-logging. Unit clauses = %d.\n", 8.0 * veci_size(&s->proof_clas) / (1<<20), s->nUnits );
|
|
|
|
// delete vectors
|
|
veci_delete(&s->order);
|
|
veci_delete(&s->trail_lim);
|
|
veci_delete(&s->tagged);
|
|
veci_delete(&s->stack);
|
|
veci_delete(&s->model);
|
|
veci_delete(&s->temp_clause);
|
|
veci_delete(&s->conf_final);
|
|
veci_delete(&s->mark_levels);
|
|
veci_delete(&s->min_lit_order);
|
|
veci_delete(&s->min_step_order);
|
|
veci_delete(&s->proof_clas);
|
|
veci_delete(&s->proof_vars);
|
|
veci_delete(&s->claActs);
|
|
veci_delete(&s->claProofs);
|
|
veci_delete(&s->clauses);
|
|
|
|
// delete arrays
|
|
if (s->vi != 0){
|
|
int i;
|
|
if ( s->wlists )
|
|
for (i = 0; i < s->size*2; i++)
|
|
veci_delete(&s->wlists[i]);
|
|
ABC_FREE(s->wlists );
|
|
ABC_FREE(s->vi );
|
|
ABC_FREE(s->trail );
|
|
ABC_FREE(s->orderpos );
|
|
ABC_FREE(s->reasons );
|
|
ABC_FREE(s->units );
|
|
ABC_FREE(s->activity );
|
|
}
|
|
ABC_FREE(s);
|
|
}
|
|
|
|
|
|
int sat_solver2_addclause__(sat_solver2* s, lit* begin, lit* end)
|
|
{
|
|
cla Cid;
|
|
lit *i,*j;
|
|
int maxvar;
|
|
lit last;
|
|
|
|
if (begin == end)
|
|
{
|
|
assert( 0 );
|
|
return false;
|
|
}
|
|
|
|
// copy clause into storage
|
|
veci_resize( &s->temp_clause, 0 );
|
|
for ( i = begin; i < end; i++ )
|
|
veci_push( &s->temp_clause, *i );
|
|
begin = veci_begin( &s->temp_clause );
|
|
end = begin + veci_size( &s->temp_clause );
|
|
|
|
//printlits(begin,end); printf("\n");
|
|
// insertion sort
|
|
maxvar = lit_var(*begin);
|
|
for (i = begin + 1; i < end; i++){
|
|
lit l = *i;
|
|
maxvar = lit_var(l) > maxvar ? lit_var(l) : maxvar;
|
|
for (j = i; j > begin && *(j-1) > l; j--)
|
|
*j = *(j-1);
|
|
*j = l;
|
|
}
|
|
sat_solver2_setnvars(s,maxvar+1);
|
|
|
|
// delete duplicates
|
|
last = lit_Undef;
|
|
for (i = j = begin; i < end; i++){
|
|
//printf("lit: "L_LIT", value = %d\n", L_lit(*i), (lit_sign(*i) ? -values[lit_var(*i)] : values[lit_var(*i)]));
|
|
if (*i == lit_neg(last) || var_value(s, lit_var(*i)) == lit_sign(*i))
|
|
return true; // tautology
|
|
else if (*i != last && var_value(s, lit_var(*i)) == varX)
|
|
last = *j++ = *i;
|
|
}
|
|
//printf("final: "); printlits(begin,j); printf("\n");
|
|
if (j == begin) // empty clause
|
|
{
|
|
assert( 0 );
|
|
return false;
|
|
}
|
|
|
|
if (j - begin == 1) // unit clause
|
|
return solver2_enqueue(s,*begin,0);
|
|
|
|
// create new clause
|
|
Cid = clause_new(s,begin,j,0,0);
|
|
return true;
|
|
}
|
|
|
|
int sat_solver2_addclause(sat_solver2* s, lit* begin, lit* end)
|
|
{
|
|
cla Cid;
|
|
lit *i,*j;
|
|
int maxvar;
|
|
assert( begin < end );
|
|
|
|
// copy clause into storage
|
|
veci_resize( &s->temp_clause, 0 );
|
|
for ( i = begin; i < end; i++ )
|
|
veci_push( &s->temp_clause, *i );
|
|
begin = veci_begin( &s->temp_clause );
|
|
end = begin + veci_size( &s->temp_clause );
|
|
|
|
// insertion sort
|
|
maxvar = lit_var(*begin);
|
|
for (i = begin + 1; i < end; i++){
|
|
lit l = *i;
|
|
maxvar = lit_var(l) > maxvar ? lit_var(l) : maxvar;
|
|
for (j = i; j > begin && *(j-1) > l; j--)
|
|
*j = *(j-1);
|
|
*j = l;
|
|
}
|
|
sat_solver2_setnvars(s,maxvar+1);
|
|
|
|
// create a new clause
|
|
Cid = clause_new( s, begin, end, 0, 0 );
|
|
// handle unit clause
|
|
if ( begin + 1 == end )
|
|
{
|
|
printf( "Adding unit clause %d\n", begin[0] );
|
|
// solver2_canceluntil(s, 0);
|
|
if ( s->fProofLogging )
|
|
var_set_unit_clause( s, lit_var(begin[0]), Cid );
|
|
if ( !solver2_enqueue(s,begin[0],0) )
|
|
assert( 0 );
|
|
}
|
|
|
|
// count literals
|
|
s->stats.clauses++;
|
|
s->stats.clauses_literals += end - begin;
|
|
return 1;
|
|
}
|
|
|
|
|
|
double luby2(double y, int x)
|
|
{
|
|
int size, seq;
|
|
for (size = 1, seq = 0; size < x+1; seq++, size = 2*size + 1);
|
|
while (size-1 != x){
|
|
size = (size-1) >> 1;
|
|
seq--;
|
|
x = x % size;
|
|
}
|
|
return pow(y, (double)seq);
|
|
}
|
|
|
|
void luby2_test()
|
|
{
|
|
int i;
|
|
for ( i = 0; i < 20; i++ )
|
|
printf( "%d ", (int)luby2(2,i) );
|
|
printf( "\n" );
|
|
}
|
|
|
|
int sat_solver2_solve(sat_solver2* s, lit* begin, lit* end, ABC_INT64_T nConfLimit, ABC_INT64_T nInsLimit, ABC_INT64_T nConfLimitGlobal, ABC_INT64_T nInsLimitGlobal)
|
|
{
|
|
int restart_iter = 0;
|
|
ABC_INT64_T nof_conflicts;
|
|
ABC_INT64_T nof_learnts = sat_solver2_nclauses(s) / 3;
|
|
lbool status = l_Undef;
|
|
// lbool* values = s->assigns;
|
|
lit* i;
|
|
|
|
s->fLastConfId = -1;
|
|
|
|
// set the external limits
|
|
// s->nCalls++;
|
|
// s->nRestarts = 0;
|
|
s->nConfLimit = 0;
|
|
s->nInsLimit = 0;
|
|
if ( nConfLimit )
|
|
s->nConfLimit = s->stats.conflicts + nConfLimit;
|
|
if ( nInsLimit )
|
|
// s->nInsLimit = s->stats.inspects + nInsLimit;
|
|
s->nInsLimit = s->stats.propagations + nInsLimit;
|
|
if ( nConfLimitGlobal && (s->nConfLimit == 0 || s->nConfLimit > nConfLimitGlobal) )
|
|
s->nConfLimit = nConfLimitGlobal;
|
|
if ( nInsLimitGlobal && (s->nInsLimit == 0 || s->nInsLimit > nInsLimitGlobal) )
|
|
s->nInsLimit = nInsLimitGlobal;
|
|
|
|
#ifndef SAT_USE_ANALYZE_FINAL
|
|
|
|
//printf("solve: "); printlits(begin, end); printf("\n");
|
|
for (i = begin; i < end; i++){
|
|
// switch (lit_sign(*i) ? -values[lit_var(*i)] : values[lit_var(*i)]){
|
|
switch (var_value(s, *i)) {
|
|
case var1: // l_True:
|
|
break;
|
|
case varX: // l_Undef
|
|
solver2_assume(s, *i);
|
|
if (solver2_propagate(s) == NULL)
|
|
break;
|
|
// fallthrough
|
|
case var0: // l_False
|
|
solver2_canceluntil(s, 0);
|
|
return l_False;
|
|
}
|
|
}
|
|
s->root_level = solver2_dlevel(s);
|
|
|
|
#endif
|
|
|
|
/*
|
|
// Perform assumptions:
|
|
root_level = assumps.size();
|
|
for (int i = 0; i < assumps.size(); i++){
|
|
Lit p = assumps[i];
|
|
assert(var(p) < nVars());
|
|
if (!solver2_assume(p)){
|
|
GClause r = reason[var(p)];
|
|
if (r != GClause_NULL){
|
|
satset* confl;
|
|
if (r.isLit()){
|
|
confl = propagate_tmpbin;
|
|
(*confl)[1] = ~p;
|
|
(*confl)[0] = r.lit();
|
|
}else
|
|
confl = r.clause();
|
|
analyzeFinal(confl, true);
|
|
conflict.push(~p);
|
|
}else
|
|
conflict.clear(),
|
|
conflict.push(~p);
|
|
cancelUntil(0);
|
|
return false; }
|
|
satset* confl = propagate();
|
|
if (confl != NULL){
|
|
analyzeFinal(confl), assert(conflict.size() > 0);
|
|
cancelUntil(0);
|
|
return false; }
|
|
}
|
|
assert(root_level == decisionLevel());
|
|
*/
|
|
|
|
#ifdef SAT_USE_ANALYZE_FINAL
|
|
// Perform assumptions:
|
|
s->root_level = end - begin;
|
|
for ( i = begin; i < end; i++ )
|
|
{
|
|
lit p = *i;
|
|
assert(lit_var(p) < s->size);
|
|
veci_push(&s->trail_lim,s->qtail);
|
|
if (!solver2_enqueue(s,p,0))
|
|
{
|
|
satset* r = get_clause(s, lit_reason(s,p));
|
|
if (r != NULL)
|
|
{
|
|
satset* confl = r;
|
|
solver2_analyze_final(s, confl, 1);
|
|
veci_push(&s->conf_final, lit_neg(p));
|
|
}
|
|
else
|
|
{
|
|
veci_resize(&s->conf_final,0);
|
|
veci_push(&s->conf_final, lit_neg(p));
|
|
// the two lines below are a bug fix by Siert Wieringa
|
|
if (var_level(s, lit_var(p)) > 0)
|
|
veci_push(&s->conf_final, p);
|
|
}
|
|
solver2_canceluntil(s, 0);
|
|
return l_False;
|
|
}
|
|
else
|
|
{
|
|
satset* confl = solver2_propagate(s);
|
|
if (confl != NULL){
|
|
solver2_analyze_final(s, confl, 0);
|
|
assert(s->conf_final.size > 0);
|
|
solver2_canceluntil(s, 0);
|
|
return l_False;
|
|
}
|
|
}
|
|
}
|
|
assert(s->root_level == solver2_dlevel(s));
|
|
#endif
|
|
|
|
// s->nCalls2++;
|
|
|
|
if (s->verbosity >= 1){
|
|
printf("==================================[MINISAT]===================================\n");
|
|
printf("| Conflicts | ORIGINAL | LEARNT | Progress |\n");
|
|
printf("| | Clauses Literals | Limit Clauses Literals Lit/Cl | |\n");
|
|
printf("==============================================================================\n");
|
|
}
|
|
|
|
while (status == l_Undef){
|
|
// int nConfs = 0;
|
|
double Ratio = (s->stats.learnts == 0)? 0.0 :
|
|
s->stats.learnts_literals / (double)s->stats.learnts;
|
|
if ( s->nRuntimeLimit && time(NULL) > s->nRuntimeLimit )
|
|
break;
|
|
|
|
if (s->verbosity >= 1)
|
|
{
|
|
printf("| %9.0f | %7.0f %8.0f | %7.0f %7.0f %8.0f %7.1f | %6.3f %% |\n",
|
|
(double)s->stats.conflicts,
|
|
(double)s->stats.clauses,
|
|
(double)s->stats.clauses_literals,
|
|
(double)nof_learnts,
|
|
(double)s->stats.learnts,
|
|
(double)s->stats.learnts_literals,
|
|
Ratio,
|
|
s->progress_estimate*100);
|
|
fflush(stdout);
|
|
}
|
|
nof_conflicts = (ABC_INT64_T)( 100 * luby2(2, restart_iter++) );
|
|
//printf( "%d ", (int)nof_conflicts );
|
|
// nConfs = s->stats.conflicts;
|
|
status = solver2_search(s, nof_conflicts, &nof_learnts);
|
|
// if ( status == l_True )
|
|
// printf( "%d ", s->stats.conflicts - nConfs );
|
|
|
|
// nof_conflicts = nof_conflicts * 3 / 2; //*= 1.5;
|
|
//printf( "%d ", s->stats.conflicts );
|
|
// quit the loop if reached an external limit
|
|
if ( s->nConfLimit && s->stats.conflicts > s->nConfLimit )
|
|
{
|
|
// printf( "Reached the limit on the number of conflicts (%d).\n", s->nConfLimit );
|
|
break;
|
|
}
|
|
// if ( s->nInsLimit && s->stats.inspects > s->nInsLimit )
|
|
if ( s->nInsLimit && s->stats.propagations > s->nInsLimit )
|
|
{
|
|
// printf( "Reached the limit on the number of implications (%d).\n", s->nInsLimit );
|
|
break;
|
|
}
|
|
if ( s->nRuntimeLimit && time(NULL) > s->nRuntimeLimit )
|
|
break;
|
|
}
|
|
//printf( "\n" );
|
|
if (s->verbosity >= 1)
|
|
printf("==============================================================================\n");
|
|
|
|
solver2_canceluntil(s,0);
|
|
return status;
|
|
}
|
|
|
|
|
|
ABC_NAMESPACE_IMPL_END
|
|
|