duplicate learnts version相关知识笔记

文献：

Stepan Kochemazov, Oleg Zaikin, Alexander A. Semenov, Victor Kondratiev:
Speeding Up CDCL Inference with Duplicate Learnt Clauses. ECAI 2020: 339-346

 

代码解读：

  solver.h中相关声明量
 

// duplicate learnts version
std::map<int32_t,std::map<uint32_t,std::unordered_map<uint64_t,uint32_t>>> ht;

 

// duplicate learnts version

uint32_t min_number_of_learnts_copies;
uint32_t dupl_db_init_size;
uint32_t max_lbd_dup;
std::chrono::microseconds duptime;
// duplicate learnts version

 

// duplicate learnts version
uint64_t duplicates_added_conflicts;
uint64_t duplicates_added_tier2;
uint64_t duplicates_added_minimization;
uint64_t dupl_db_size;

// duplicate learnts version

 

 

/ duplicate learnts version
int is_duplicate (std::vector<uint32_t>&c); //returns TRUE if a clause is duplicate
// duplicate learnts version
   
   
  
 1 int Solver::is_duplicate(std::vector<uint32_t>&c){
 2    auto time_point_0 = std::chrono::high_resolution_clock::now();
 3     dupl_db_size++;
 4     int res = 0;    
 5     
 6     int sz = c.size();
 7     std::vector<uint32_t> tmp(c);    
 8     sort(tmp.begin(),tmp.end());
 9     
10     uint64_t hash = 0;    
11     
12     for (int i =0; i<sz; i++) {
13         hash ^= tmp[i] + 0x9e3779b9 + (hash << 6) + (hash>> 2);     
14     }    
15     
16     int32_t head = tmp[0];
17     auto it0 = ht.find(head);
18     if (it0 != ht.end()){
19         auto it1= ht[head].find(sz);
20         if (it1 != ht[head].end()){
21             auto it2 = ht[head][sz].find(hash);
22             if (it2 != ht[head][sz].end()){
23                 it2->second++;
24                 res = it2->second;            
25             }
26             else{
27                 ht[head][sz][hash]=1;
28             }
29         }
30         else{            
31             ht[head][sz][hash]=1;
32         }
33     }else{        
34         ht[head][sz][hash]=1;
35     } 
36     auto time_point_1 = std::chrono::high_resolution_clock::now();
37     duptime += std::chrono::duration_cast<std::chrono::microseconds>(time_point_1-time_point_0);    
38     return res;
39 }

 

 
 

 

  1 bool Solver::simplifyLearnt_tier2()
  2 {
  3     int beforeSize, afterSize;
  4     int learnts_tier2_size_before = learnts_tier2.size();
  5 
  6     int ci, cj, li, lj;
  7     bool sat, false_lit;
  8     unsigned int nblevels;
  9     ////
 10     //printf("learnts_x size : %d\n", learnts_x.size());
 11 
 12     ////
 13     int nbSimplified = 0;
 14     int nbSimplifing = 0;
 15 
 16     for (ci = 0, cj = 0; ci < learnts_tier2.size(); ci++){
 17         CRef cr = learnts_tier2[ci];
 18         Clause& c = ca[cr];
 19 
 20         if (removed(cr)) continue;
 21         else if (c.simplified()){
 22             learnts_tier2[cj++] = learnts_tier2[ci];
 23             ////
 24             nbSimplified++;
 25         }
 26         else{
 27             int saved_size=c.size();
 28             //            if (drup_file){
 29             //                    add_oc.clear();
 30             //                    for (int i = 0; i < c.size(); i++) add_oc.push(c[i]); }
 31             ////
 32             nbSimplifing++;
 33             sat = false_lit = false;
 34             for (int i = 0; i < c.size(); i++){
 35                 if (value(c[i]) == l_True){
 36                     sat = true;
 37                     break;
 38                 }
 39                 else if (value(c[i]) == l_False){
 40                     false_lit = true;
 41                 }
 42             }
 43             if (sat){
 44                 removeClause(cr);
 45             }
 46             else{
 47                 detachClause(cr, true);
 48 
 49                 if (false_lit){
 50                     for (li = lj = 0; li < c.size(); li++){
 51                         if (value(c[li]) != l_False){
 52                             c[lj++] = c[li];
 53                         }
 54                     }
 55                     c.shrink(li - lj);
 56                 }
 57 
 58                 beforeSize = c.size();
 59                 assert(c.size() > 1);
 60                 // simplify a learnt clause c
 61                 simplifyLearnt(c);
 62                 assert(c.size() > 0);
 63                 afterSize = c.size();
 64                 
 65                 if(drup_file && saved_size!=c.size()){
 66 
 67 #ifdef BIN_DRUP
 68                     binDRUP('a', c , drup_file);
 69                     //                    binDRUP('d', add_oc, drup_file);
 70 #else
 71                     for (int i = 0; i < c.size(); i++)
 72                         fprintf(drup_file, "%i ", (var(c[i]) + 1) * (-2 * sign(c[i]) + 1));
 73                     fprintf(drup_file, "0\n");
 74 
 75                     //                    fprintf(drup_file, "d ");
 76                     //                    for (int i = 0; i < add_oc.size(); i++)
 77                     //                        fprintf(drup_file, "%i ", (var(add_oc[i]) + 1) * (-2 * sign(add_oc[i]) + 1));
 78                     //                    fprintf(drup_file, "0\n");
 79 #endif
 80                 }
 81 
 82                 //printf("beforeSize: %2d, afterSize: %2d\n", beforeSize, afterSize);
 83 
 84                 if (c.size() == 1){
 85                     // when unit clause occur, enqueue and propagate
 86                     uncheckedEnqueue(c[0]);
 87                     if (propagate() != CRef_Undef){
 88                         ok = false;
 89                         return false;
 90                     }
 91                     // delete the clause memory in logic
 92                     c.mark(1);
 93                     ca.free(cr);
 94 //#ifdef BIN_DRUP
 95 //                    binDRUP('d', c, drup_file);
 96 //#else
 97 //                    fprintf(drup_file, "d ");
 98 //                    for (int i = 0; i < c.size(); i++)
 99 //                        fprintf(drup_file, "%i ", (var(c[i]) + 1) * (-2 * sign(c[i]) + 1));
100 //                    fprintf(drup_file, "0\n");
101 //#endif
102                 }
103                 else{
104                     
105 
106                     nblevels = computeLBD(c);
107                     if (nblevels < c.lbd()){
108                         //printf("lbd-before: %d, lbd-after: %d\n", c.lbd(), nblevels);
109                         c.set_lbd(nblevels);
110                     }
111                      //duplicate learnts 
112                     int id = 0;                    
113                     
114                     std::vector<uint32_t> tmp;
115                     for (int i = 0; i < c.size(); i++)                           
116                         tmp.push_back(c[i].x);
117                     id = is_duplicate(tmp);
118                      
119                                         
120                     //duplicate learnts 
121 
122                     if (id < min_number_of_learnts_copies+2){
123                         attachClause(cr);
124                         learnts_tier2[cj++] = learnts_tier2[ci];                    
125                         if (id == min_number_of_learnts_copies+1){                            
126                             duplicates_added_minimization++;                                  
127                         }
128                         if ((c.lbd() <= core_lbd_cut)||(id == min_number_of_learnts_copies+1)){
129                         //if (id == min_number_of_learnts_copies+1){
130                             cj--;
131                             learnts_core.push(cr);
132                             c.mark(CORE);
133                         }
134 
135                         c.setSimplified(true);
136                     }
137                 }
138             }
139         }
140     }
141     learnts_tier2.shrink(ci - cj);
142 
143     //    printf("c nbLearnts_tier2 %d / %d, nbSimplified: %d, nbSimplifing: %d\n",
144     //           learnts_tier2_size_before, learnts_tier2.size(), nbSimplified, nbSimplifing);
145 
146     return true;
147 
148 }
bool Solver::simplifyLearnt_tier2()

 

  1 lbool Solver::search(int& nof_conflicts)
  2 {
  3     assert(ok);
  4     int         backtrack_level;    
  5     int         lbd;
  6     vec<Lit>    learnt_clause;
  7     bool        cached = false;
  8     starts++;
  9     int conflictCs = 0;        //本次重启冲突次数计数    
 10 
 11     // simplify
 12     。。。。。。
 13     
 14    
 15     for (;;){
 16           
 17         confl = propagate();        
 18         
 19         if (confl != CRef_Undef)
 20         {      
 21 
 22             //以下保持原来的search函数代码段
 23             if (VSIDS){
 24                 if (--timer == 0 && var_decay < 0.95) timer = 5000, var_decay += 0.01;
 25             }else
 26                 if (step_size > min_step_size) step_size -= step_size_dec;
 27 
 28             conflicts++; nof_conflicts--; conflictCs++;
 29             //if (conflicts == 100000 && learnts_core.size() < 100) core_lbd_cut = 5;
 30             ConflictData data = FindConflictLevel(confl);
 31             if (data.nHighestLevel == 0) return l_False;
 32             if (data.bOnlyOneLitFromHighest)
 33             {
 34                 cancelUntil(data.nHighestLevel - 1);
 35                 continue;
 36             }
 37             
 38             learnt_clause.clear();
 39             if(conflicts > 50000) DISTANCE = 0; 
 40             else DISTANCE=1;
 41 
 42             
 43             if(VSIDS && DISTANCE){                 
 44                 mycollectFirstUIP(confl);                
 45             }            
 46 
 47             backtrack_level = 0;            
 48 
 49             // check chrono backtrack condition
 50             if ((confl_to_chrono < 0 || confl_to_chrono <= conflicts) && chrono > -1 && (decisionLevel() - backtrack_level) >= chrono)
 51             {
 52                 ++chrono_backtrack;
 53                 cancelUntil(data.nHighestLevel -1);
 54                 
 55             }
 56             else // default behavior
 57             {
 58                 ++non_chrono_backtrack;
 59                 cancelUntil(backtrack_level);                
 60             }            
 61 
 62             lbd--;
 63             if (VSIDS){
 64                 cached = false;
 65                 conflicts_VSIDS++;
 66                 lbd_queue.push(lbd);
 67                 global_lbd_sum += (lbd > 50 ? 50 : lbd); }
 68 
 69             if (learnt_clause.size() == 1){                
 70                 uncheckedEnqueue(learnt_clause[0]);
 71             }else{
 72                 CRef cr = ca.alloc(learnt_clause, true);
 73                 
 74                 ca[cr].set_lbd(lbd);
 75 
 76                 //duplicate learnts 
 77                 int  id = 0;
 78                 if (lbd <= max_lbd_dup){                        
 79                     std::vector<uint32_t> tmp;
 80                     for (int i = 0; i < learnt_clause.size(); i++)
 81                         tmp.push_back(learnt_clause[i].x);
 82                     id = is_duplicate(tmp);             
 83                     if (id == min_number_of_learnts_copies +1){
 84                         duplicates_added_conflicts++;                        
 85                     }                    
 86                     if (id == min_number_of_learnts_copies){
 87                         duplicates_added_tier2++;
 88                     }                                        
 89                 }
 90                 //duplicate learnts
 91 
 92 
 93                 if ((lbd <= core_lbd_cut) || (id == min_number_of_learnts_copies+1)){
 94                     learnts_core.push(cr);
 95                     ca[cr].mark(CORE);
 96                 }else if ((lbd <= tier2_lbd_cut)||(id == min_number_of_learnts_copies)){
 97                     learnts_tier2.push(cr);
 98                     ca[cr].mark(TIER2);
 99                     ca[cr].touched() = conflicts;
100                 }else{
101                     learnts_local.push(cr);
102                     claBumpActivity(ca[cr]); }
103                 attachClause(cr);
104                 uncheckedEnqueue(learnt_clause[0], backtrack_level, cr);
105 #ifdef PRINT_OUT
106                 std::cout << "new " << ca[cr] << "\n";
107                 std::cout << "ci " << learnt_clause[0] << " l " << backtrack_level << "\n";
108 #endif                
109             }
110             if (drup_file){
111 #ifdef BIN_DRUP
112                 binDRUP('a', learnt_clause, drup_file);
113 #else
114                 for (int i = 0; i < learnt_clause.size(); i++)
115                     fprintf(drup_file, "%i ", (var(learnt_clause[i]) + 1) * (-2 * sign(learnt_clause[i]) + 1));
116                 fprintf(drup_file, "0\n");
117 #endif
118             }
119 
120             if (VSIDS) varDecayActivity();
121             claDecayActivity();    
122 
123             //
124             
125         }
126         else
127         {           
128             // NO CONFLICT            
129             bool restart = false;
130             if (!VSIDS)
131                 restart = nof_conflicts <= 0;
132             else if (!cached){
133                 restart = lbd_queue.full() && (lbd_queue.avg() * 0.8 > global_lbd_sum / conflicts_VSIDS);
134                 cached = true;
135             }
136 
137             if (restart /*|| !withinBudget()*/){
138                 //return l_False; //for test 
139 
140                 lbd_queue.clear();
141                 cached = false;
142                 // Reached bound on number of conflicts:
143                 progress_estimate = progressEstimate();
144                 cancelUntil(0);
145                 
146                 return l_Undef; 
147             }
148 
149             // Simplify the set of problem clauses:
150             if (decisionLevel() == 0 && !simplify()){
151                 return l_False; }  
152 
153             if (conflicts >= next_T2_reduce){
154                 next_T2_reduce = conflicts + 10000;
155                 reduceDB_Tier2(); }
156             if (conflicts >= next_L_reduce){
157                 next_L_reduce = conflicts + 15000;
158                 reduceDB(); }
159 
160             Lit next = lit_Undef;
161             
162          
163             // New variable decision:
164             decisions++;
165             next = pickBranchLit();
166 
167             if (next == lit_Undef){
168                 decisions--;
169                 // Model found:
170                 return l_True;
171             }
172             
173 
174             // Increase decision level and enqueue 'next'
175             newDecisionLevel();
176             uncheckedEnqueue(next, decisionLevel());
177             nextLit = next;  // update on 2020-03-10
178 #ifdef PRINT_OUT            
179             std::cout << "d " << next << " l " << decisionLevel() << "\n";
180 #endif            
181         }
182     }
183 }
lbool Solver::search(int& nof_conflicts)

 

 

 

posted on 2022-06-20 10:05  海阔凭鱼跃越  阅读(29)  评论(0)  编辑  收藏  举报