PbSolver_convert.cc

/*****************************************************************************[PbSolver_convert.cc]
Copyright (c) 2005-2010, Niklas Een, Niklas Sorensson

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NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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**************************************************************************************************/

#include "PbSolver.h"
#include "Hardware.h"

//-------------------------------------------------------------------------------------------------
void    linearAddition (const Linear& c, vec<Formula>& out);        // From: PbSolver_convertAdd.C
Formula buildConstraint(const Linear& c, int max_cost = INT_MAX);   // From: PbSolver_convertSort.C
Formula convertToBdd   (const Linear& c, int max_cost = INT_MAX);   // From: PbSolver_convertBdd.C
//-------------------------------------------------------------------------------------------------


bool PbSolver::convertPbs(bool first_call)
{
    vec<Formula>    converted_constrs;
    ConvertT saved_opt_convert = opt_convert;

    if (first_call){
        findIntervals();
        if (!rewriteAlmostClauses()) {
            sat_solver.addEmptyClause();
            return false;
        }
    }

    for (int i = 0; i < constrs.size(); i++) {
        if (constrs[i] == NULL) continue;
        Linear& c   = *constrs[i]; assert(c.lo != Int_MIN || c.hi != Int_MAX);

        if (opt_verbosity >= 1 && first_call) /**/ reportf("---[%4d]---> ", constrs.size() - 1 - i);
    
        try { // M. Piotrow 11.10.2017
            if (opt_convert == ct_Sorters)
                converted_constrs.push(buildConstraint(c)), first_call ? ++srtEncodings : ++srtOptEncodings;
            else if (opt_convert == ct_Adders)
                linearAddition(c, converted_constrs), first_call ? ++addEncodings : ++addOptEncodings;
            else if (opt_convert == ct_BDDs)
                converted_constrs.push(convertToBdd(c)), first_call ? ++bddEncodings : ++bddOptEncodings;
            else if (opt_convert == ct_Mixed) {
                int adder_cost = estimatedAdderCost(c);
                //int different_cs = 1; for (int i = 1; i < c.size; i++) if (c(i) != c(i-1)) different_cs++;
                //**/printf("estimatedAdderCost: %d\n", estimatedAdderCost(c));
                /*if (first_call || opt_convert_goal == opt_convert) {
  	            Int max_coeff = c(c.size-1);
  	            int max_log = 0; while ((max_coeff >>= 1) > 0) max_log++;
                    double add_sort_factor = (max_log > 20 ? 1.0/(max_log-20) : max_log <= 10 ? 15.0 : 22.0-max_log);
                    Formula result = buildConstraint(c, (int)(adder_cost * opt_sort_thres * add_sort_factor));
                    if (result == _undef_) {
                        result = convertToBdd(c, (int)(adder_cost * opt_bdd_thres));
                        if (result != _undef_) 
                            if (!first_call) opt_convert = ct_BDDs, ++bddOptEncodings; else ++bddEncodings;
                    } else if (!first_call) opt_convert = ct_Sorters, ++srtOptEncodings; else ++srtEncodings;
                    if (result == _undef_) linearAddition(c, converted_constrs), first_call ? ++addEncodings : ++addOptEncodings;
                    else converted_constrs.push(result);
                } else*/ {
                    Formula result = buildConstraint(c, (int)(adder_cost * opt_sort_thres)); 
                    if (result == _undef_) {
                        result = convertToBdd(c, (int)(adder_cost * opt_bdd_thres));
                        if (result != _undef_)
                            if (!first_call) opt_convert = ct_BDDs, ++bddOptEncodings; else ++bddEncodings; 
                    } else if (!first_call) opt_convert = ct_Sorters, ++srtOptEncodings; else ++srtEncodings;
                    if (result == _undef_) linearAddition(c, converted_constrs), first_call ? ++addEncodings : ++addOptEncodings;
                    else converted_constrs.push(result);
                }
            } else assert(false);
            constrs[i]->~Linear(); constrs[i] = NULL;
            if (!opt_shared_fmls && FEnv::nodes.size() >= 100000) { 
                clausify(sat_solver, converted_constrs); converted_constrs.clear(); 
            }
            opt_convert = saved_opt_convert;
        } catch (std::bad_alloc& ba) { // M. Piotrow 11.10.2017
	    FEnv::pop(); i-=1;
	    if (opt_convert == ct_Sorters)  { opt_convert = ct_BDDs; continue; }
	    if (opt_convert != ct_Adders)  { opt_convert = ct_Adders; continue; }
            else {
	        reportf("Out of memery in converting constraints: %s\n",ba.what());
	        exit(1); //throw(std::bad_alloc);
	    }
        }
        if (!okay()) return false;
    }
    constrs.clear();
    mem.clear();

    try { // M. Piotrow 15.06.2018
      clausify(sat_solver, converted_constrs);
    } catch (std::bad_alloc& ba) { // M. Piotrow 15.06.2018
      reportf("Out of memery in clausifying constraints: %s\n",ba.what());
      exit(1);
    }
    
    return okay();
}