diff options
Diffstat (limited to 'src/prop/minisat/simp')
| -rw-r--r-- | src/prop/minisat/simp/Main.C | 415 | ||||
| -rw-r--r-- | src/prop/minisat/simp/Makefile | 11 | ||||
| -rw-r--r-- | src/prop/minisat/simp/SimpSolver.C | 711 | ||||
| -rw-r--r-- | src/prop/minisat/simp/SimpSolver.h | 174 |
4 files changed, 0 insertions, 1311 deletions
diff --git a/src/prop/minisat/simp/Main.C b/src/prop/minisat/simp/Main.C deleted file mode 100644 index b6d194631..000000000 --- a/src/prop/minisat/simp/Main.C +++ /dev/null @@ -1,415 +0,0 @@ -/******************************************************************************************[Main.C] -MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson - -Permission is hereby granted, free of charge, to any person obtaining a copy of this software and -associated documentation files (the "Software"), to deal in the Software without restriction, -including without limitation the rights to use, copy, modify, merge, publish, distribute, -sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is -furnished to do so, subject to the following conditions: - -The above copyright notice and this permission notice shall be included in all copies or -substantial portions of the Software. - -THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT -NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND -NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, -DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT -OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. -**************************************************************************************************/ - -#include <ctime> -#include <cstring> -#include <stdint.h> -#include <errno.h> - -#include <signal.h> -#include <zlib.h> - -#include "SimpSolver.h" - -/*************************************************************************************/ -#ifdef _MSC_VER -#include <ctime> - -static inline double cpuTime(void) { - return (double)clock() / CLOCKS_PER_SEC; } -#else - -#include <sys/time.h> -#include <sys/resource.h> -#include <unistd.h> - -static inline double cpuTime(void) { - struct rusage ru; - getrusage(RUSAGE_SELF, &ru); - return (double)ru.ru_utime.tv_sec + (double)ru.ru_utime.tv_usec / 1000000; } -#endif - - -#if defined(__linux__) -static inline int memReadStat(int field) -{ - char name[256]; - pid_t pid = getpid(); - sprintf(name, "/proc/%d/statm", pid); - FILE* in = fopen(name, "rb"); - if (in == NULL) return 0; - int value; - for (; field >= 0; field--) - fscanf(in, "%d", &value); - fclose(in); - return value; -} -static inline uint64_t memUsed() { return (uint64_t)memReadStat(0) * (uint64_t)getpagesize(); } - - -#elif defined(__FreeBSD__) -static inline uint64_t memUsed(void) { - struct rusage ru; - getrusage(RUSAGE_SELF, &ru); - return ru.ru_maxrss*1024; } - - -#else -static inline uint64_t memUsed() { return 0; } -#endif - -#if defined(__linux__) -#include <fpu_control.h> -#endif - - -//================================================================================================= -// DIMACS Parser: - -#define CHUNK_LIMIT 1048576 - -class StreamBuffer { - gzFile in; - char buf[CHUNK_LIMIT]; - int pos; - int size; - - void assureLookahead() { - if (pos >= size) { - pos = 0; - size = gzread(in, buf, sizeof(buf)); } } - -public: - StreamBuffer(gzFile i) : in(i), pos(0), size(0) { - assureLookahead(); } - - int operator * () { return (pos >= size) ? EOF : buf[pos]; } - void operator ++ () { pos++; assureLookahead(); } -}; - -//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -template<class B> -static void skipWhitespace(B& in) { - while ((*in >= 9 && *in <= 13) || *in == 32) - ++in; } - -template<class B> -static void skipLine(B& in) { - for (;;){ - if (*in == EOF || *in == '\0') return; - if (*in == '\n') { ++in; return; } - ++in; } } - -template<class B> -static int parseInt(B& in) { - int val = 0; - bool neg = false; - skipWhitespace(in); - if (*in == '-') neg = true, ++in; - else if (*in == '+') ++in; - if (*in < '0' || *in > '9') reportf("PARSE ERROR! Unexpected char: %c\n", *in), exit(3); - while (*in >= '0' && *in <= '9') - val = val*10 + (*in - '0'), - ++in; - return neg ? -val : val; } - -template<class B> -static void readClause(B& in, SimpSolver& S, vec<Lit>& lits) { - int parsed_lit, var; - lits.clear(); - for (;;){ - parsed_lit = parseInt(in); - if (parsed_lit == 0) break; - var = abs(parsed_lit)-1; - while (var >= S.nVars()) S.newVar(); - lits.push( (parsed_lit > 0) ? Lit(var) : ~Lit(var) ); - } -} - -template<class B> -static bool match(B& in, char* str) { - for (; *str != 0; ++str, ++in) - if (*str != *in) - return false; - return true; -} - - -template<class B> -static void parse_DIMACS_main(B& in, SimpSolver& S) { - vec<Lit> lits; - for (;;){ - skipWhitespace(in); - if (*in == EOF) break; - else if (*in == 'p'){ - if (match(in, "p cnf")){ - int vars = parseInt(in); - int clauses = parseInt(in); - reportf("| Number of variables: %-12d |\n", vars); - reportf("| Number of clauses: %-12d |\n", clauses); - - // SATRACE'06 hack - if (clauses > 4000000) - S.eliminate(true); - }else{ - reportf("PARSE ERROR! Unexpected char: %c\n", *in), exit(3); - } - } else if (*in == 'c' || *in == 'p') - skipLine(in); - else{ - readClause(in, S, lits); - S.addClause(lits); } - } -} - -// Inserts problem into solver. -// -static void parse_DIMACS(gzFile input_stream, SimpSolver& S) { - StreamBuffer in(input_stream); - parse_DIMACS_main(in, S); } - - -//================================================================================================= - - -void printStats(Solver& S) -{ - double cpu_time = cpuTime(); - uint64_t mem_used = memUsed(); - reportf("restarts : %lld\n", S.starts); - reportf("conflicts : %-12lld (%.0f /sec)\n", S.conflicts , S.conflicts /cpu_time); - reportf("decisions : %-12lld (%4.2f %% random) (%.0f /sec)\n", S.decisions, (float)S.rnd_decisions*100 / (float)S.decisions, S.decisions /cpu_time); - reportf("propagations : %-12lld (%.0f /sec)\n", S.propagations, S.propagations/cpu_time); - reportf("conflict literals : %-12lld (%4.2f %% deleted)\n", S.tot_literals, (S.max_literals - S.tot_literals)*100 / (double)S.max_literals); - if (mem_used != 0) reportf("Memory used : %.2f MB\n", mem_used / 1048576.0); - reportf("CPU time : %g s\n", cpu_time); -} - -SimpSolver* solver; -static void SIGINT_handler(int signum) { - reportf("\n"); reportf("*** INTERRUPTED ***\n"); - printStats(*solver); - reportf("\n"); reportf("*** INTERRUPTED ***\n"); - exit(1); } - - -//================================================================================================= -// Main: - -void printUsage(char** argv) -{ - reportf("USAGE: %s [options] <input-file> <result-output-file>\n\n where input may be either in plain or gzipped DIMACS.\n\n", argv[0]); - reportf("OPTIONS:\n\n"); - reportf(" -pre = {none,once}\n"); - reportf(" -asymm\n"); - reportf(" -rcheck\n"); - reportf(" -grow = <num> [ >0 ]\n"); - reportf(" -polarity-mode = {true,false,rnd}\n"); - reportf(" -decay = <num> [ 0 - 1 ]\n"); - reportf(" -rnd-freq = <num> [ 0 - 1 ]\n"); - reportf(" -dimacs = <output-file>\n"); - reportf(" -verbosity = {0,1,2}\n"); - reportf("\n"); -} - -typedef enum { pre_none, pre_once, pre_repeat } preprocessMode; - -const char* hasPrefix(const char* str, const char* prefix) -{ - int len = strlen(prefix); - if (strncmp(str, prefix, len) == 0) - return str + len; - else - return NULL; -} - - -int main(int argc, char** argv) -{ - reportf("This is MiniSat 2.0 beta\n"); -#if defined(__linux__) - fpu_control_t oldcw, newcw; - _FPU_GETCW(oldcw); newcw = (oldcw & ~_FPU_EXTENDED) | _FPU_DOUBLE; _FPU_SETCW(newcw); - reportf("WARNING: for repeatability, setting FPU to use double precision\n"); -#endif - preprocessMode pre = pre_once; - const char* dimacs = NULL; - const char* freeze = NULL; - SimpSolver S; - S.verbosity = 1; - - // This just grew and grew, and I didn't have time to do sensible argument parsing yet :) - // - int i, j; - const char* value; - for (i = j = 0; i < argc; i++){ - if ((value = hasPrefix(argv[i], "-polarity-mode="))){ - if (strcmp(value, "true") == 0) - S.polarity_mode = Solver::polarity_true; - else if (strcmp(value, "false") == 0) - S.polarity_mode = Solver::polarity_false; - else if (strcmp(value, "rnd") == 0) - S.polarity_mode = Solver::polarity_rnd; - else{ - reportf("ERROR! unknown polarity-mode %s\n", value); - exit(0); } - - }else if ((value = hasPrefix(argv[i], "-rnd-freq="))){ - double rnd; - if (sscanf(value, "%lf", &rnd) <= 0 || rnd < 0 || rnd > 1){ - reportf("ERROR! illegal rnd-freq constant %s\n", value); - exit(0); } - S.random_var_freq = rnd; - - }else if ((value = hasPrefix(argv[i], "-decay="))){ - double decay; - if (sscanf(value, "%lf", &decay) <= 0 || decay <= 0 || decay > 1){ - reportf("ERROR! illegal decay constant %s\n", value); - exit(0); } - S.var_decay = 1 / decay; - - }else if ((value = hasPrefix(argv[i], "-verbosity="))){ - int verbosity = (int)strtol(value, NULL, 10); - if (verbosity == 0 && errno == EINVAL){ - reportf("ERROR! illegal verbosity level %s\n", value); - exit(0); } - S.verbosity = verbosity; - - }else if ((value = hasPrefix(argv[i], "-pre="))){ - if (strcmp(value, "none") == 0) - pre = pre_none; - else if (strcmp(value, "once") == 0) - pre = pre_once; - else if (strcmp(value, "repeat") == 0){ - pre = pre_repeat; - reportf("ERROR! preprocessing mode \"repeat\" is not supported at the moment.\n"); - exit(0); - }else{ - reportf("ERROR! unknown preprocessing mode %s\n", value); - exit(0); } - }else if (strcmp(argv[i], "-asymm") == 0){ - S.asymm_mode = true; - }else if (strcmp(argv[i], "-rcheck") == 0){ - S.redundancy_check = true; - }else if ((value = hasPrefix(argv[i], "-grow="))){ - int grow = (int)strtol(value, NULL, 10); - if (grow == 0 && errno == EINVAL){ - reportf("ERROR! illegal grow constant %s\n", &argv[i][6]); - exit(0); } - S.grow = grow; - }else if ((value = hasPrefix(argv[i], "-dimacs="))){ - dimacs = value; - }else if ((value = hasPrefix(argv[i], "-freeze="))){ - freeze = value; - }else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "-help") == 0){ - printUsage(argv); - exit(0); - }else if (strncmp(argv[i], "-", 1) == 0){ - reportf("ERROR! unknown flag %s\n", argv[i]); - exit(0); - }else - argv[j++] = argv[i]; - } - argc = j; - - double cpu_time = cpuTime(); - - if (pre == pre_none) - S.eliminate(true); - - solver = &S; - signal(SIGINT,SIGINT_handler); - signal(SIGHUP,SIGINT_handler); - - if (argc == 1) - reportf("Reading from standard input... Use '-h' or '--help' for help.\n"); - - gzFile in = (argc == 1) ? gzdopen(0, "rb") : gzopen(argv[1], "rb"); - if (in == NULL) - reportf("ERROR! Could not open file: %s\n", argc == 1 ? "<stdin>" : argv[1]), exit(1); - - reportf("============================[ Problem Statistics ]=============================\n"); - reportf("| |\n"); - - parse_DIMACS(in, S); - gzclose(in); - FILE* res = (argc >= 3) ? fopen(argv[2], "wb") : NULL; - - - double parse_time = cpuTime() - cpu_time; - reportf("| Parsing time: %-12.2f s |\n", parse_time); - - /*HACK: Freeze variables*/ - if (freeze != NULL && pre != pre_none){ - int count = 0; - FILE* in = fopen(freeze, "rb"); - for(;;){ - Var x; - fscanf(in, "%d", &x); - if (x == 0) break; - x--; - - /**/assert(S.n_occ[toInt(Lit(x))] + S.n_occ[toInt(~Lit(x))] != 0); - /**/assert(S.value(x) == l_Undef); - S.setFrozen(x, true); - count++; - } - fclose(in); - reportf("| Frozen vars : %-12.0f |\n", (double)count); - } - /*END*/ - - if (!S.simplify()){ - reportf("Solved by unit propagation\n"); - if (res != NULL) fprintf(res, "UNSAT\n"), fclose(res); - printf("UNSATISFIABLE\n"); - exit(20); - } - - if (dimacs){ - if (pre != pre_none) - S.eliminate(true); - reportf("==============================[ Writing DIMACS ]===============================\n"); - S.toDimacs(dimacs); - printStats(S); - exit(0); - }else{ - bool ret = S.solve(true, true); - printStats(S); - reportf("\n"); - - printf(ret ? "SATISFIABLE\n" : "UNSATISFIABLE\n"); - if (res != NULL){ - if (ret){ - fprintf(res, "SAT\n"); - for (int i = 0; i < S.nVars(); i++) - if (S.model[i] != l_Undef) - fprintf(res, "%s%s%d", (i==0)?"":" ", (S.model[i]==l_True)?"":"-", i+1); - fprintf(res, " 0\n"); - }else - fprintf(res, "UNSAT\n"); - fclose(res); - } -#ifdef NDEBUG - exit(ret ? 10 : 20); // (faster than "return", which will invoke the destructor for 'Solver') -#endif - } - -} diff --git a/src/prop/minisat/simp/Makefile b/src/prop/minisat/simp/Makefile deleted file mode 100644 index a1db4951b..000000000 --- a/src/prop/minisat/simp/Makefile +++ /dev/null @@ -1,11 +0,0 @@ -MTL = ../mtl -CORE = ../core -CHDRS = $(wildcard *.h) $(wildcard $(MTL)/*.h) -EXEC = minisat -CFLAGS = -I$(MTL) -I$(CORE) -Wall -ffloat-store -LFLAGS = -lz - -CSRCS = $(wildcard *.C) -COBJS = $(addsuffix .o, $(basename $(CSRCS))) $(CORE)/Solver.o - -include ../mtl/template.mk diff --git a/src/prop/minisat/simp/SimpSolver.C b/src/prop/minisat/simp/SimpSolver.C deleted file mode 100644 index 00f93402f..000000000 --- a/src/prop/minisat/simp/SimpSolver.C +++ /dev/null @@ -1,711 +0,0 @@ -/************************************************************************************[SimpSolver.C] -MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson - -Permission is hereby granted, free of charge, to any person obtaining a copy of this software and -associated documentation files (the "Software"), to deal in the Software without restriction, -including without limitation the rights to use, copy, modify, merge, publish, distribute, -sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is -furnished to do so, subject to the following conditions: - -The above copyright notice and this permission notice shall be included in all copies or -substantial portions of the Software. - -THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT -NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND -NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, -DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT -OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. -**************************************************************************************************/ - -#include "Sort.h" -#include "SimpSolver.h" - - -//================================================================================================= -// Constructor/Destructor: - -namespace CVC4 { -namespace prop { -namespace minisat { - -SimpSolver::SimpSolver(SatSolver* proxy, context::Context* context) : - Solver(proxy, context) - , grow (0) - , asymm_mode (false) - , redundancy_check (false) - , merges (0) - , asymm_lits (0) - , remembered_clauses (0) - , elimorder (1) - , use_simplification (true) - , elim_heap (ElimLt(n_occ)) - , bwdsub_assigns (0) -{ - vec<Lit> dummy(1,lit_Undef); - bwdsub_tmpunit = Clause_new(dummy); - remove_satisfied = false; -} - - -SimpSolver::~SimpSolver() -{ - free(bwdsub_tmpunit); - - // NOTE: elimtable.size() might be lower than nVars() at the moment - for (int i = 0; i < elimtable.size(); i++) - for (int j = 0; j < elimtable[i].eliminated.size(); j++) - free(elimtable[i].eliminated[j]); -} - - -Var SimpSolver::newVar(bool sign, bool dvar, bool theoryAtom) { - Var v = Solver::newVar(sign, dvar,theoryAtom); - - if (use_simplification){ - n_occ .push(0); - n_occ .push(0); - occurs .push(); - frozen .push((char)theoryAtom); - touched .push(0); - elim_heap.insert(v); - elimtable.push(); - } - return v; } - - - -bool SimpSolver::solve(const vec<Lit>& assumps, bool do_simp, bool turn_off_simp) { - vec<Var> extra_frozen; - bool result = true; - - do_simp &= use_simplification; - - if (do_simp){ - // Assumptions must be temporarily frozen to run variable elimination: - for (int i = 0; i < assumps.size(); i++){ - Var v = var(assumps[i]); - - // If an assumption has been eliminated, remember it. - if (isEliminated(v)) - remember(v); - - if (!frozen[v]){ - // Freeze and store. - setFrozen(v, true); - extra_frozen.push(v); - } } - - result = eliminate(turn_off_simp); - } - - if (result) - result = Solver::solve(assumps); - - if (result) { - extendModel(); -#ifndef NDEBUG - verifyModel(); -#endif - } - - if (do_simp) - // Unfreeze the assumptions that were frozen: - for (int i = 0; i < extra_frozen.size(); i++) - setFrozen(extra_frozen[i], false); - - return result; -} - - - -bool SimpSolver::addClause(vec<Lit>& ps, ClauseType type) -{ - for (int i = 0; i < ps.size(); i++) - if (isEliminated(var(ps[i]))) - remember(var(ps[i])); - - int nclauses = clauses.size(); - - if (redundancy_check && implied(ps)) - return true; - - if (!Solver::addClause(ps, type)) - return false; - - if (use_simplification && clauses.size() == nclauses + 1){ - Clause& c = *clauses.last(); - - subsumption_queue.insert(&c); - - for (int i = 0; i < c.size(); i++){ - assert(occurs.size() > var(c[i])); - assert(!find(occurs[var(c[i])], &c)); - - occurs[var(c[i])].push(&c); - n_occ[toInt(c[i])]++; - touched[var(c[i])] = 1; - assert(elimtable[var(c[i])].order == 0); - if (elim_heap.inHeap(var(c[i]))) - elim_heap.increase_(var(c[i])); - } - } - - return true; -} - - -void SimpSolver::removeClause(Clause& c) -{ - Debug("minisat") << "SimpSolver::removeClause(" << c << ")" << std::endl; - assert(!c.learnt()); - - if (use_simplification) - for (int i = 0; i < c.size(); i++){ - n_occ[toInt(c[i])]--; - updateElimHeap(var(c[i])); - } - - detachClause(c); - c.mark(1); -} - - -bool SimpSolver::strengthenClause(Clause& c, Lit l) -{ - assert(decisionLevel() == 0); - assert(c.mark() == 0); - assert(!c.learnt()); - assert(find(watches[toInt(~c[0])], &c)); - assert(find(watches[toInt(~c[1])], &c)); - - // FIX: this is too inefficient but would be nice to have (properly implemented) - // if (!find(subsumption_queue, &c)) - subsumption_queue.insert(&c); - - // If l is watched, delete it from watcher list and watch a new literal - if (c[0] == l || c[1] == l){ - Lit other = c[0] == l ? c[1] : c[0]; - if (c.size() == 2){ - removeClause(c); - c.strengthen(l); - }else{ - c.strengthen(l); - remove(watches[toInt(~l)], &c); - - // Add a watch for the correct literal - watches[toInt(~(c[1] == other ? c[0] : c[1]))].push(&c); - - // !! this version assumes that remove does not change the order !! - //watches[toInt(~c[1])].push(&c); - clauses_literals -= 1; - } - } - else{ - c.strengthen(l); - clauses_literals -= 1; - } - - // if subsumption-indexing is active perform the necessary updates - if (use_simplification){ - remove(occurs[var(l)], &c); - n_occ[toInt(l)]--; - updateElimHeap(var(l)); - } - - return c.size() == 1 ? enqueue(c[0]) && propagate(CHECK_WITHOUTH_PROPAGATION_QUICK) == NULL : true; -} - - -// Returns FALSE if clause is always satisfied ('out_clause' should not be used). -bool SimpSolver::merge(const Clause& _ps, const Clause& _qs, Var v, vec<Lit>& out_clause) -{ - merges++; - out_clause.clear(); - - bool ps_smallest = _ps.size() < _qs.size(); - const Clause& ps = ps_smallest ? _qs : _ps; - const Clause& qs = ps_smallest ? _ps : _qs; - - for (int i = 0; i < qs.size(); i++){ - if (var(qs[i]) != v){ - for (int j = 0; j < ps.size(); j++) - if (var(ps[j]) == var(qs[i])) { - if (ps[j] == ~qs[i]) - return false; - else - goto next; - } - out_clause.push(qs[i]); - } - next:; - } - - for (int i = 0; i < ps.size(); i++) - if (var(ps[i]) != v) - out_clause.push(ps[i]); - - return true; -} - - -// Returns FALSE if clause is always satisfied. -bool SimpSolver::merge(const Clause& _ps, const Clause& _qs, Var v) -{ - merges++; - - bool ps_smallest = _ps.size() < _qs.size(); - const Clause& ps = ps_smallest ? _qs : _ps; - const Clause& qs = ps_smallest ? _ps : _qs; - const Lit* __ps = (const Lit*)ps; - const Lit* __qs = (const Lit*)qs; - - for (int i = 0; i < qs.size(); i++){ - if (var(__qs[i]) != v){ - for (int j = 0; j < ps.size(); j++) - if (var(__ps[j]) == var(__qs[i])) { - if (__ps[j] == ~__qs[i]) - return false; - else - goto next; - } - } - next:; - } - - return true; -} - - -void SimpSolver::gatherTouchedClauses() -{ - //fprintf(stderr, "Gathering clauses for backwards subsumption\n"); - int ntouched = 0; - for (int i = 0; i < touched.size(); i++) - if (touched[i]){ - const vec<Clause*>& cs = getOccurs(i); - ntouched++; - for (int j = 0; j < cs.size(); j++) - if (cs[j]->mark() == 0){ - subsumption_queue.insert(cs[j]); - cs[j]->mark(2); - } - touched[i] = 0; - } - - //fprintf(stderr, "Touched variables %d of %d yields %d clauses to check\n", ntouched, touched.size(), clauses.size()); - for (int i = 0; i < subsumption_queue.size(); i++) - subsumption_queue[i]->mark(0); -} - - -bool SimpSolver::implied(const vec<Lit>& c) -{ - assert(decisionLevel() == 0); - - trail_lim.push(trail.size()); - for (int i = 0; i < c.size(); i++) - if (value(c[i]) == l_True){ - cancelUntil(0); - return false; - }else if (value(c[i]) != l_False){ - assert(value(c[i]) == l_Undef); - uncheckedEnqueue(~c[i]); - } - - bool result = propagate(CHECK_WITHOUTH_PROPAGATION_QUICK) != NULL; - cancelUntil(0); - return result; -} - - -// Backward subsumption + backward subsumption resolution -bool SimpSolver::backwardSubsumptionCheck(bool verbose) -{ - int cnt = 0; - int subsumed = 0; - int deleted_literals = 0; - assert(decisionLevel() == 0); - - while (subsumption_queue.size() > 0 || bwdsub_assigns < trail.size()){ - - // Check top-level assignments by creating a dummy clause and placing it in the queue: - if (subsumption_queue.size() == 0 && bwdsub_assigns < trail.size()){ - Lit l = trail[bwdsub_assigns++]; - (*bwdsub_tmpunit)[0] = l; - bwdsub_tmpunit->calcAbstraction(); - assert(bwdsub_tmpunit->mark() == 0); - subsumption_queue.insert(bwdsub_tmpunit); } - - Clause& c = *subsumption_queue.peek(); subsumption_queue.pop(); - - if (c.mark()) continue; - - if (verbose && verbosity >= 2 && cnt++ % 1000 == 0) - reportf("subsumption left: %10d (%10d subsumed, %10d deleted literals)\r", subsumption_queue.size(), subsumed, deleted_literals); - - assert(c.size() > 1 || value(c[0]) == l_True); // Unit-clauses should have been propagated before this point. - - // Find best variable to scan: - Var best = var(c[0]); - for (int i = 1; i < c.size(); i++) - if (occurs[var(c[i])].size() < occurs[best].size()) - best = var(c[i]); - - // Search all candidates: - vec<Clause*>& _cs = getOccurs(best); - Clause** cs = (Clause**)_cs; - - for (int j = 0; j < _cs.size(); j++) - if (c.mark()) - break; - else if (!cs[j]->mark() && cs[j] != &c){ - Lit l = c.subsumes(*cs[j]); - - if (l == lit_Undef) - subsumed++, removeClause(*cs[j]); - else if (l != lit_Error){ - deleted_literals++; - - if (!strengthenClause(*cs[j], ~l)) - return false; - - // Did current candidate get deleted from cs? Then check candidate at index j again: - if (var(l) == best) - j--; - } - } - } - - return true; -} - - -bool SimpSolver::asymm(Var v, Clause& c) -{ - assert(decisionLevel() == 0); - - if (c.mark() || satisfied(c)) return true; - - trail_lim.push(trail.size()); - Lit l = lit_Undef; - for (int i = 0; i < c.size(); i++) - if (var(c[i]) != v && value(c[i]) != l_False) - uncheckedEnqueue(~c[i]); - else - l = c[i]; - - if (propagate(CHECK_WITHOUTH_PROPAGATION_QUICK) != NULL){ - cancelUntil(0); - asymm_lits++; - if (!strengthenClause(c, l)) - return false; - }else - cancelUntil(0); - - return true; -} - - -bool SimpSolver::asymmVar(Var v) -{ - assert(!frozen[v]); - assert(use_simplification); - - vec<Clause*> pos, neg; - const vec<Clause*>& cls = getOccurs(v); - - if (value(v) != l_Undef || cls.size() == 0) - return true; - - for (int i = 0; i < cls.size(); i++) - if (!asymm(v, *cls[i])) - return false; - - return backwardSubsumptionCheck(); -} - - -void SimpSolver::verifyModel() -{ - bool failed = false; - int cnt = 0; - // NOTE: elimtable.size() might be lower than nVars() at the moment - for (int i = 0; i < elimtable.size(); i++) - if (elimtable[i].order > 0) - for (int j = 0; j < elimtable[i].eliminated.size(); j++){ - cnt++; - Clause& c = *elimtable[i].eliminated[j]; - for (int k = 0; k < c.size(); k++) - if (modelValue(c[k]) == l_True) - goto next; - - reportf("unsatisfied clause: "); - printClause(*elimtable[i].eliminated[j]); - reportf("\n"); - failed = true; - next:; - } - - assert(!failed); - reportf("Verified %d eliminated clauses.\n", cnt); -} - - -bool SimpSolver::eliminateVar(Var v, bool fail) -{ - if (!fail && asymm_mode && !asymmVar(v)) return false; - - const vec<Clause*>& cls = getOccurs(v); - -// if (value(v) != l_Undef || cls.size() == 0) return true; - if (value(v) != l_Undef) return true; - - // Split the occurrences into positive and negative: - vec<Clause*> pos, neg; - for (int i = 0; i < cls.size(); i++) - (find(*cls[i], Lit(v)) ? pos : neg).push(cls[i]); - - // Check if number of clauses decreases: - int cnt = 0; - for (int i = 0; i < pos.size(); i++) - for (int j = 0; j < neg.size(); j++) - if (merge(*pos[i], *neg[j], v) && ++cnt > cls.size() + grow) - return true; - - // Delete and store old clauses: - setDecisionVar(v, false); - elimtable[v].order = elimorder++; - assert(elimtable[v].eliminated.size() == 0); - for (int i = 0; i < cls.size(); i++){ - elimtable[v].eliminated.push(Clause_new(*cls[i])); - removeClause(*cls[i]); } - - // Produce clauses in cross product: - int top = clauses.size(); - vec<Lit> resolvent; - for (int i = 0; i < pos.size(); i++) - for (int j = 0; j < neg.size(); j++) - if (merge(*pos[i], *neg[j], v, resolvent) && !addClause(resolvent, CLAUSE_CONFLICT)) - return false; - - // DEBUG: For checking that a clause set is saturated with respect to variable elimination. - // If the clause set is expected to be saturated at this point, this constitutes an - // error. - if (fail){ - reportf("eliminated var %d, %d <= %d\n", v+1, cnt, cls.size()); - reportf("previous clauses:\n"); - for (int i = 0; i < cls.size(); i++){ - printClause(*cls[i]); reportf("\n"); } - reportf("new clauses:\n"); - for (int i = top; i < clauses.size(); i++){ - printClause(*clauses[i]); reportf("\n"); } - assert(0); } - - return backwardSubsumptionCheck(); -} - - -void SimpSolver::remember(Var v) -{ - assert(decisionLevel() == 0); - assert(isEliminated(v)); - - vec<Lit> clause; - - // Re-activate variable: - elimtable[v].order = 0; - setDecisionVar(v, true); // Not good if the variable wasn't a decision variable before. Not sure how to fix this right now. - - if (use_simplification) - updateElimHeap(v); - - // Reintroduce all old clauses which may implicitly remember other clauses: - for (int i = 0; i < elimtable[v].eliminated.size(); i++){ - Clause& c = *elimtable[v].eliminated[i]; - clause.clear(); - for (int j = 0; j < c.size(); j++) - clause.push(c[j]); - - remembered_clauses++; - check(addClause(clause, CLAUSE_PROBLEM)); - free(&c); - } - - elimtable[v].eliminated.clear(); -} - - -void SimpSolver::extendModel() -{ - vec<Var> vs; - - // NOTE: elimtable.size() might be lower than nVars() at the moment - for (int v = 0; v < elimtable.size(); v++) - if (elimtable[v].order > 0) - vs.push(v); - - sort(vs, ElimOrderLt(elimtable)); - - for (int i = 0; i < vs.size(); i++){ - Var v = vs[i]; - Lit l = lit_Undef; - - for (int j = 0; j < elimtable[v].eliminated.size(); j++){ - Clause& c = *elimtable[v].eliminated[j]; - - for (int k = 0; k < c.size(); k++) - if (var(c[k]) == v) - l = c[k]; - else if (modelValue(c[k]) != l_False) - goto next; - - assert(l != lit_Undef); - model[v] = lbool(!sign(l)); - break; - - next:; - } - - if (model[v] == l_Undef) - model[v] = l_True; - } -} - - -bool SimpSolver::eliminate(bool turn_off_elim) -{ - if (!ok || !use_simplification) - return ok; - - // Main simplification loop: - //assert(subsumption_queue.size() == 0); - //gatherTouchedClauses(); - while (subsumption_queue.size() > 0 || elim_heap.size() > 0){ - - //fprintf(stderr, "subsumption phase: (%d)\n", subsumption_queue.size()); - if (!backwardSubsumptionCheck(true)) - return false; - - //fprintf(stderr, "elimination phase:\n (%d)", elim_heap.size()); - for (int cnt = 0; !elim_heap.empty(); cnt++){ - Var elim = elim_heap.removeMin(); - - if (verbosity >= 2 && cnt % 100 == 0) - reportf("elimination left: %10d\r", elim_heap.size()); - - if (!frozen[elim] && !eliminateVar(elim)) - return false; - } - - assert(subsumption_queue.size() == 0); - gatherTouchedClauses(); - } - - // Cleanup: - cleanUpClauses(); - order_heap.filter(VarFilter(*this)); - -#ifdef INVARIANTS - // Check that no more subsumption is possible: - reportf("Checking that no more subsumption is possible\n"); - for (int i = 0; i < clauses.size(); i++){ - if (i % 1000 == 0) - reportf("left %10d\r", clauses.size() - i); - - assert(clauses[i]->mark() == 0); - for (int j = 0; j < i; j++) - assert(clauses[i]->subsumes(*clauses[j]) == lit_Error); - } - reportf("done.\n"); - - // Check that no more elimination is possible: - reportf("Checking that no more elimination is possible\n"); - for (int i = 0; i < nVars(); i++) - if (!frozen[i]) eliminateVar(i, true); - reportf("done.\n"); - checkLiteralCount(); -#endif - - // If no more simplification is needed, free all simplification-related data structures: - if (turn_off_elim){ - use_simplification = false; - touched.clear(true); - occurs.clear(true); - n_occ.clear(true); - subsumption_queue.clear(true); - elim_heap.clear(true); - remove_satisfied = true; - } - - - return true; -} - - -void SimpSolver::cleanUpClauses() -{ - int i , j; - vec<Var> dirty; - for (i = 0; i < clauses.size(); i++) - if (clauses[i]->mark() == 1){ - Clause& c = *clauses[i]; - for (int k = 0; k < c.size(); k++) - if (!seen[var(c[k])]){ - seen[var(c[k])] = 1; - dirty.push(var(c[k])); - } } - - for (i = 0; i < dirty.size(); i++){ - cleanOcc(dirty[i]); - seen[dirty[i]] = 0; } - - for (i = j = 0; i < clauses.size(); i++) - if (clauses[i]->mark() == 1) - free(clauses[i]); - else - clauses[j++] = clauses[i]; - clauses.shrink(i - j); -} - - -//================================================================================================= -// Convert to DIMACS: - - -void SimpSolver::toDimacs(FILE* f, Clause& c) -{ - if (satisfied(c)) return; - - for (int i = 0; i < c.size(); i++) - if (value(c[i]) != l_False) - fprintf(f, "%s%d ", sign(c[i]) ? "-" : "", var(c[i])+1); - fprintf(f, "0\n"); -} - - -void SimpSolver::toDimacs(const char* file) -{ - assert(decisionLevel() == 0); - FILE* f = fopen(file, "wr"); - if (f != NULL){ - - // Cannot use removeClauses here because it is not safe - // to deallocate them at this point. Could be improved. - int cnt = 0; - for (int i = 0; i < clauses.size(); i++) - if (!satisfied(*clauses[i])) - cnt++; - - fprintf(f, "p cnf %d %d\n", nVars(), cnt); - - for (int i = 0; i < clauses.size(); i++) - toDimacs(f, *clauses[i]); - - fprintf(stderr, "Wrote %d clauses...\n", clauses.size()); - }else - fprintf(stderr, "could not open file %s\n", file); -} - -}/* CVC4::prop::minisat namespace */ -}/* CVC4::prop namespace */ -}/* CVC4 namespace */ diff --git a/src/prop/minisat/simp/SimpSolver.h b/src/prop/minisat/simp/SimpSolver.h deleted file mode 100644 index 3da574f6c..000000000 --- a/src/prop/minisat/simp/SimpSolver.h +++ /dev/null @@ -1,174 +0,0 @@ -/************************************************************************************[SimpSolver.h] -MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson - -Permission is hereby granted, free of charge, to any person obtaining a copy of this software and -associated documentation files (the "Software"), to deal in the Software without restriction, -including without limitation the rights to use, copy, modify, merge, publish, distribute, -sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is -furnished to do so, subject to the following conditions: - -The above copyright notice and this permission notice shall be included in all copies or -substantial portions of the Software. - -THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT -NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND -NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, -DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT -OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. -**************************************************************************************************/ - -#include "cvc4_private.h" - -#ifndef __CVC4__PROP__MINISAT__SIMP_SOLVER_H -#define __CVC4__PROP__MINISAT__SIMP_SOLVER_H - -#include <cstdio> -#include <cassert> - -#include "../mtl/Queue.h" -#include "../core/Solver.h" - -namespace CVC4 { -namespace prop { - -class SatSolver; - -namespace minisat { - -class SimpSolver : public Solver { - public: - // Constructor/Destructor: - // - SimpSolver(SatSolver* proxy, context::Context* context); - CVC4_PUBLIC ~SimpSolver(); - - // Problem specification: - // - Var newVar (bool polarity = true, bool dvar = true, bool theoryAtom = false); - bool addClause (vec<Lit>& ps, ClauseType type); - - // Variable mode: - // - void setFrozen (Var v, bool b); // If a variable is frozen it will not be eliminated. - - // Solving: - // - bool solve (const vec<Lit>& assumps, bool do_simp = true, bool turn_off_simp = false); - bool solve (bool do_simp = true, bool turn_off_simp = false); - bool eliminate (bool turn_off_elim = false); // Perform variable elimination based simplification. - - // Generate a (possibly simplified) DIMACS file: - // - void toDimacs (const char* file); - - // Mode of operation: - // - int grow; // Allow a variable elimination step to grow by a number of clauses (default to zero). - bool asymm_mode; // Shrink clauses by asymmetric branching. - bool redundancy_check; // Check if a clause is already implied. Prett costly, and subsumes subsumptions :) - - // Statistics: - // - int merges; - int asymm_lits; - int remembered_clauses; - -// protected: - public: - - // Helper structures: - // - struct ElimData { - int order; // 0 means not eliminated, >0 gives an index in the elimination order - vec<Clause*> eliminated; - ElimData() : order(0) {} }; - - struct ElimOrderLt { - const vec<ElimData>& elimtable; - ElimOrderLt(const vec<ElimData>& et) : elimtable(et) {} - bool operator()(Var x, Var y) { return elimtable[x].order > elimtable[y].order; } }; - - struct ElimLt { - const vec<int>& n_occ; - ElimLt(const vec<int>& no) : n_occ(no) {} - int cost (Var x) const { return n_occ[toInt(Lit(x))] * n_occ[toInt(~Lit(x))]; } - bool operator()(Var x, Var y) const { return cost(x) < cost(y); } }; - - - // Solver state: - // - int elimorder; - bool use_simplification; - vec<ElimData> elimtable; - vec<char> touched; - vec<vec<Clause*> > occurs; - vec<int> n_occ; - Heap<ElimLt> elim_heap; - Queue<Clause*> subsumption_queue; - vec<char> frozen; - int bwdsub_assigns; - - // Temporaries: - // - Clause* bwdsub_tmpunit; - - // Main internal methods: - // - bool asymm (Var v, Clause& c); - bool asymmVar (Var v); - void updateElimHeap (Var v); - void cleanOcc (Var v); - vec<Clause*>& getOccurs (Var x); - void gatherTouchedClauses (); - bool merge (const Clause& _ps, const Clause& _qs, Var v, vec<Lit>& out_clause); - bool merge (const Clause& _ps, const Clause& _qs, Var v); - bool backwardSubsumptionCheck (bool verbose = false); - bool eliminateVar (Var v, bool fail = false); - void remember (Var v); - void extendModel (); - void verifyModel (); - - void removeClause (Clause& c); - bool strengthenClause (Clause& c, Lit l); - void cleanUpClauses (); - bool implied (const vec<Lit>& c); - void toDimacs (FILE* f, Clause& c); - bool isEliminated (Var v) const; - -}; - - -//================================================================================================= -// Implementation of inline methods: - -inline void SimpSolver::updateElimHeap(Var v) { - if (elimtable[v].order == 0) - elim_heap.update(v); } - -inline void SimpSolver::cleanOcc(Var v) { - assert(use_simplification); - Clause **begin = (Clause**)occurs[v]; - Clause **end = begin + occurs[v].size(); - Clause **i, **j; - for (i = begin, j = end; i < j; i++) - if ((*i)->mark() == 1){ - *i = *(--j); - i--; - } - //occurs[v].shrink_(end - j); // This seems slower. Why?! - occurs[v].shrink(end - j); -} - -inline vec<Clause*>& SimpSolver::getOccurs(Var x) { - cleanOcc(x); return occurs[x]; } - -inline bool SimpSolver::isEliminated (Var v) const { return v < elimtable.size() && elimtable[v].order != 0; } -inline void SimpSolver::setFrozen (Var v, bool b) { frozen[v] = (char)b; if (b) { updateElimHeap(v); } } -inline bool SimpSolver::solve (bool do_simp, bool turn_off_simp) { vec<Lit> tmp; return solve(tmp, do_simp, turn_off_simp); } - -}/* CVC4::prop::minisat namespace */ -}/* CVC4::prop namespace */ -}/* CVC4 namespace */ - -//================================================================================================= -#endif /* __CVC4__PROP__MINISAT__SIMP_SOLVER_H */ |