diff options
Diffstat (limited to 'src/preprocessing/passes')
| -rw-r--r-- | src/preprocessing/passes/quantifier_macros.cpp | 550 | ||||
| -rw-r--r-- | src/preprocessing/passes/quantifier_macros.h | 89 |
2 files changed, 639 insertions, 0 deletions
diff --git a/src/preprocessing/passes/quantifier_macros.cpp b/src/preprocessing/passes/quantifier_macros.cpp new file mode 100644 index 000000000..e3bc02309 --- /dev/null +++ b/src/preprocessing/passes/quantifier_macros.cpp @@ -0,0 +1,550 @@ +/********************* */ +/*! \file quantifier_macros.cpp + ** \verbatim + ** Top contributors (to current version): + ** Andrew Reynolds, Tim King, Kshitij Bansal + ** This file is part of the CVC4 project. + ** Copyright (c) 2009-2018 by the authors listed in the file AUTHORS + ** in the top-level source directory) and their institutional affiliations. + ** All rights reserved. See the file COPYING in the top-level source + ** directory for licensing information.\endverbatim + ** + ** \brief Sort inference module + ** + ** This class implements quantifiers macro definitions. + **/ + +#include "preprocessing/passes/quantifier_macros.h" + +#include <vector> + +#include "options/quantifiers_modes.h" +#include "options/quantifiers_options.h" +#include "proof/proof_manager.h" +#include "smt/smt_engine.h" +#include "smt/smt_engine_scope.h" +#include "theory/arith/arith_msum.h" +#include "theory/quantifiers/ematching/trigger.h" +#include "theory/quantifiers/term_database.h" +#include "theory/quantifiers/term_util.h" +#include "theory/quantifiers_engine.h" +#include "theory/rewriter.h" + +using namespace std; +using namespace CVC4::theory; +using namespace CVC4::theory::quantifiers; +using namespace CVC4::kind; + +namespace CVC4 { +namespace preprocessing { +namespace passes { + +QuantifierMacros::QuantifierMacros(PreprocessingPassContext* preprocContext) + : PreprocessingPass(preprocContext, "quantifier-macros"), + d_ground_macros(false) +{ +} + +PreprocessingPassResult QuantifierMacros::applyInternal( + AssertionPipeline* assertionsToPreprocess) +{ + bool success; + do + { + success = simplify(assertionsToPreprocess->ref(), true); + } while (success); + finalizeDefinitions(); + clearMaps(); + return PreprocessingPassResult::NO_CONFLICT; +} + +void QuantifierMacros::clearMaps() +{ + d_macro_basis.clear(); + d_macro_defs.clear(); + d_macro_defs_new.clear(); + d_macro_def_contains.clear(); + d_simplify_cache.clear(); + d_quant_macros.clear(); + d_ground_macros = false; +} + +bool QuantifierMacros::simplify( std::vector< Node >& assertions, bool doRewrite ){ + unsigned rmax = options::macrosQuantMode()==MACROS_QUANT_MODE_ALL ? 2 : 1; + for( unsigned r=0; r<rmax; r++ ){ + d_ground_macros = (r==0); + Trace("macros") << "Find macros, ground=" << d_ground_macros << "..." << std::endl; + //first, collect macro definitions + std::vector< Node > macro_assertions; + for( int i=0; i<(int)assertions.size(); i++ ){ + Trace("macros-debug") << " process assertion " << assertions[i] << std::endl; + if( processAssertion( assertions[i] ) ){ + PROOF( + if( std::find( macro_assertions.begin(), macro_assertions.end(), assertions[i] )==macro_assertions.end() ){ + macro_assertions.push_back( assertions[i] ); + } + ); + //process this assertion again + i--; + } + } + Trace("macros") << "...finished process, #new def = " << d_macro_defs_new.size() << std::endl; + if( doRewrite && !d_macro_defs_new.empty() ){ + bool retVal = false; + Trace("macros") << "Do simplifications..." << std::endl; + //now, rewrite based on macro definitions + for( unsigned i=0; i<assertions.size(); i++ ){ + Node curr = simplify( assertions[i] ); + if( curr!=assertions[i] ){ + curr = Rewriter::rewrite( curr ); + Trace("macros-rewrite") << "Rewrite " << assertions[i] << " to " << curr << std::endl; + //for now, it is dependent upon all assertions involving macros, this is an over-approximation. + //a more fine-grained unsat core computation would require caching dependencies for each subterm of the formula, + // which is expensive. + PROOF(ProofManager::currentPM()->addDependence(curr, assertions[i]); + for (unsigned j = 0; j < macro_assertions.size(); j++) { + if (macro_assertions[j] != assertions[i]) + { + ProofManager::currentPM()->addDependence( + curr, macro_assertions[j]); + } + }); + assertions[i] = curr; + retVal = true; + } + } + d_macro_defs_new.clear(); + if( retVal ){ + return true; + } + } + } + if( Trace.isOn("macros-warn") ){ + for( unsigned i=0; i<assertions.size(); i++ ){ + debugMacroDefinition( assertions[i], assertions[i] ); + } + } + return false; +} + +bool QuantifierMacros::processAssertion( Node n ) { + if( n.getKind()==AND ){ + for( unsigned i=0; i<n.getNumChildren(); i++ ){ + if( processAssertion( n[i] ) ){ + return true; + } + } + }else if( n.getKind()==FORALL && d_quant_macros.find( n )==d_quant_macros.end() ){ + std::vector< Node > args; + for( size_t j=0; j<n[0].getNumChildren(); j++ ){ + args.push_back( n[0][j] ); + } + Node nproc = n[1]; + if( !d_macro_defs_new.empty() ){ + nproc = simplify( nproc ); + if( nproc!=n[1] ){ + nproc = Rewriter::rewrite( nproc ); + } + } + //look at the body of the quantifier for macro definition + if( process( nproc, true, args, n ) ){ + d_quant_macros[n] = true; + return true; + } + } + return false; +} + +bool QuantifierMacros::containsBadOp( Node n, Node op, std::vector< Node >& opc, std::map< Node, bool >& visited ){ + if( visited.find( n )==visited.end() ){ + visited[n] = true; + if( n.getKind()==APPLY_UF ){ + Node nop = n.getOperator(); + if( nop==op || d_macro_defs.find( nop )!=d_macro_defs.end() ){ + return true; + } + if( std::find( opc.begin(), opc.end(), nop )==opc.end() ){ + opc.push_back( nop ); + } + }else if( d_ground_macros && n.getKind()==FORALL ){ + return true; + } + for( size_t i=0; i<n.getNumChildren(); i++ ){ + if( containsBadOp( n[i], op, opc, visited ) ){ + return true; + } + } + } + return false; +} + +bool QuantifierMacros::isMacroLiteral( Node n, bool pol ){ + return pol && n.getKind()==EQUAL; +} + +bool QuantifierMacros::isGroundUfTerm( Node f, Node n ) { + Node icn = d_preprocContext->getTheoryEngine() + ->getQuantifiersEngine() + ->getTermUtil() + ->substituteBoundVariablesToInstConstants(n, f); + Trace("macros-debug2") << "Get free variables in " << icn << std::endl; + std::vector< Node > var; + quantifiers::TermUtil::computeInstConstContainsForQuant(f, icn, var); + Trace("macros-debug2") << "Get trigger variables for " << icn << std::endl; + std::vector< Node > trigger_var; + inst::Trigger::getTriggerVariables( icn, f, trigger_var ); + Trace("macros-debug2") << "Done." << std::endl; + //only if all variables are also trigger variables + return trigger_var.size()>=var.size(); +} + +bool QuantifierMacros::isBoundVarApplyUf( Node n ) { + Assert( n.getKind()==APPLY_UF ); + TypeNode tno = n.getOperator().getType(); + std::map< Node, bool > vars; + // allow if a vector of unique variables of the same type as UF arguments + for( unsigned i=0; i<n.getNumChildren(); i++ ){ + if( n[i].getKind()!=BOUND_VARIABLE ){ + return false; + } + if( n[i].getType()!=tno[i] ){ + return false; + } + if( vars.find( n[i] )==vars.end() ){ + vars[n[i]] = true; + }else{ + return false; + } + } + return true; +} + +void QuantifierMacros::getMacroCandidates( Node n, std::vector< Node >& candidates, std::map< Node, bool >& visited ){ + if( visited.find( n )==visited.end() ){ + visited[n] = true; + if( n.getKind()==APPLY_UF ){ + if( isBoundVarApplyUf( n ) ){ + candidates.push_back( n ); + } + }else if( n.getKind()==PLUS ){ + for( size_t i=0; i<n.getNumChildren(); i++ ){ + getMacroCandidates( n[i], candidates, visited ); + } + }else if( n.getKind()==MULT ){ + //if the LHS is a constant + if( n.getNumChildren()==2 && n[0].isConst() ){ + getMacroCandidates( n[1], candidates, visited ); + } + }else if( n.getKind()==NOT ){ + getMacroCandidates( n[0], candidates, visited ); + } + } +} + +Node QuantifierMacros::solveInEquality( Node n, Node lit ){ + if( lit.getKind()==EQUAL ){ + //return the opposite side of the equality if defined that way + for( int i=0; i<2; i++ ){ + if( lit[i]==n ){ + return lit[i==0 ? 1 : 0]; + }else if( lit[i].getKind()==NOT && lit[i][0]==n ){ + return lit[i==0 ? 1 : 0].negate(); + } + } + std::map<Node, Node> msum; + if (ArithMSum::getMonomialSumLit(lit, msum)) + { + Node veq_c; + Node val; + int res = ArithMSum::isolate(n, msum, veq_c, val, EQUAL); + if (res != 0 && veq_c.isNull()) + { + return val; + } + } + } + Trace("macros-debug") << "Cannot find for " << lit << " " << n << std::endl; + return Node::null(); +} + +bool QuantifierMacros::getFreeVariables( Node n, std::vector< Node >& v_quant, std::vector< Node >& vars, bool retOnly, std::map< Node, bool >& visited ){ + if( visited.find( n )==visited.end() ){ + visited[n] = true; + if( std::find( v_quant.begin(), v_quant.end(), n )!=v_quant.end() ){ + if( std::find( vars.begin(), vars.end(), n )==vars.end() ){ + if( retOnly ){ + return true; + }else{ + vars.push_back( n ); + } + } + } + for( size_t i=0; i<n.getNumChildren(); i++ ){ + if( getFreeVariables( n[i], v_quant, vars, retOnly, visited ) ){ + return true; + } + } + } + return false; +} + +bool QuantifierMacros::getSubstitution( std::vector< Node >& v_quant, std::map< Node, Node >& solved, + std::vector< Node >& vars, std::vector< Node >& subs, bool reqComplete ){ + bool success = true; + for( size_t a=0; a<v_quant.size(); a++ ){ + if( !solved[ v_quant[a] ].isNull() ){ + vars.push_back( v_quant[a] ); + subs.push_back( solved[ v_quant[a] ] ); + }else{ + if( reqComplete ){ + success = false; + break; + } + } + } + return success; +} + +bool QuantifierMacros::process( Node n, bool pol, std::vector< Node >& args, Node f ){ + Trace("macros-debug") << " process " << n << std::endl; + if( n.getKind()==NOT ){ + return process( n[0], !pol, args, f ); + }else if( n.getKind()==AND || n.getKind()==OR ){ + //bool favorPol = (n.getKind()==AND)==pol; + //conditional? + }else if( n.getKind()==ITE ){ + //can not do anything + }else if( n.getKind()==APPLY_UF ){ + //predicate case + if( isBoundVarApplyUf( n ) ){ + Node op = n.getOperator(); + if( d_macro_defs.find( op )==d_macro_defs.end() ){ + Node n_def = NodeManager::currentNM()->mkConst( pol ); + for( unsigned i=0; i<n.getNumChildren(); i++ ){ + std::stringstream ss; + ss << "mda_" << op << ""; + Node v = NodeManager::currentNM()->mkSkolem( ss.str(), n[i].getType(), "created during macro definition recognition" ); + d_macro_basis[op].push_back( v ); + } + //contains no ops + std::vector< Node > op_contains; + //add the macro + addMacro( op, n_def, op_contains ); + return true; + } + } + }else{ + //literal case + if( isMacroLiteral( n, pol ) ){ + Trace("macros-debug") << "Check macro literal : " << n << std::endl; + std::map< Node, bool > visited; + std::vector< Node > candidates; + for( size_t i=0; i<n.getNumChildren(); i++ ){ + getMacroCandidates( n[i], candidates, visited ); + } + for( size_t i=0; i<candidates.size(); i++ ){ + Node m = candidates[i]; + Node op = m.getOperator(); + Trace("macros-debug") << "Check macro candidate : " << m << std::endl; + if( d_macro_defs.find( op )==d_macro_defs.end() ){ + std::vector< Node > fvs; + visited.clear(); + getFreeVariables( m, args, fvs, false, visited ); + //get definition and condition + Node n_def = solveInEquality( m, n ); //definition for the macro + if( !n_def.isNull() ){ + Trace("macros-debug") << m << " is possible macro in " << f << std::endl; + Trace("macros-debug") << " corresponding definition is : " << n_def << std::endl; + visited.clear(); + //definition must exist and not contain any free variables apart from fvs + if( !getFreeVariables( n_def, args, fvs, true, visited ) ){ + Trace("macros-debug") << "...free variables are contained." << std::endl; + visited.clear(); + //cannot contain a defined operator, opc is list of functions it contains + std::vector< Node > opc; + if( !containsBadOp( n_def, op, opc, visited ) ){ + Trace("macros-debug") << "...does not contain bad (recursive) operator." << std::endl; + //must be ground UF term if mode is GROUND_UF + if( options::macrosQuantMode()!=MACROS_QUANT_MODE_GROUND_UF || isGroundUfTerm( f, n_def ) ){ + Trace("macros-debug") << "...respects ground-uf constraint." << std::endl; + //now we must rewrite candidates[i] to a term of form g( x1, ..., xn ) where + // x1 ... xn are distinct variables + if( d_macro_basis[op].empty() ){ + for( size_t a=0; a<m.getNumChildren(); a++ ){ + std::stringstream ss; + ss << "mda_" << op << ""; + Node v = NodeManager::currentNM()->mkSkolem( ss.str(), m[a].getType(), "created during macro definition recognition" ); + d_macro_basis[op].push_back( v ); + } + } + std::map< Node, Node > solved; + for( size_t a=0; a<m.getNumChildren(); a++ ){ + solved[m[a]] = d_macro_basis[op][a]; + } + std::vector< Node > vars; + std::vector< Node > subs; + if( getSubstitution( fvs, solved, vars, subs, true ) ){ + n_def = n_def.substitute( vars.begin(), vars.end(), subs.begin(), subs.end() ); + addMacro( op, n_def, opc ); + return true; + } + } + } + } + } + } + } + } + } + return false; +} + +Node QuantifierMacros::simplify( Node n ){ + if( n.getNumChildren()==0 ){ + return n; + }else{ + std::map< Node, Node >::iterator itn = d_simplify_cache.find( n ); + if( itn!=d_simplify_cache.end() ){ + return itn->second; + }else{ + Node ret = n; + Trace("macros-debug") << " simplify " << n << std::endl; + std::vector< Node > children; + bool childChanged = false; + for( size_t i=0; i<n.getNumChildren(); i++ ){ + Node nn = simplify( n[i] ); + children.push_back( nn ); + childChanged = childChanged || nn!=n[i]; + } + bool retSet = false; + if( n.getKind()==APPLY_UF ){ + Node op = n.getOperator(); + std::map< Node, Node >::iterator it = d_macro_defs.find( op ); + if( it!=d_macro_defs.end() && !it->second.isNull() ){ + //only apply if children are subtypes of arguments + bool success = true; + // FIXME : this can be eliminated when we have proper typing rules + std::vector< Node > cond; + TypeNode tno = op.getType(); + for( unsigned i=0; i<children.size(); i++ ){ + Node etc = TypeNode::getEnsureTypeCondition( children[i], tno[i] ); + if( etc.isNull() ){ + //if this does fail, we are incomplete, since we are eliminating quantified formula corresponding to op, + // and not ensuring it applies to n when its types are correct. + //Assert( false ); + success = false; + break; + }else if( !etc.isConst() ){ + cond.push_back( etc ); + } + Assert( children[i].getType().isSubtypeOf( tno[i] ) ); + } + if( success ){ + //do substitution if necessary + ret = it->second; + std::map< Node, std::vector< Node > >::iterator itb = d_macro_basis.find( op ); + if( itb!=d_macro_basis.end() ){ + ret = ret.substitute( itb->second.begin(), itb->second.end(), children.begin(), children.end() ); + } + if( !cond.empty() ){ + Node cc = cond.size()==1 ? cond[0] : NodeManager::currentNM()->mkNode( kind::AND, cond ); + ret = NodeManager::currentNM()->mkNode( kind::ITE, cc, ret, n ); + } + retSet = true; + } + } + } + if( !retSet && childChanged ){ + if( n.getMetaKind() == kind::metakind::PARAMETERIZED ){ + children.insert( children.begin(), n.getOperator() ); + } + ret = NodeManager::currentNM()->mkNode( n.getKind(), children ); + } + d_simplify_cache[n] = ret; + return ret; + } + } +} + +void QuantifierMacros::debugMacroDefinition( Node oo, Node n ) { + //for debugging, ensure that all previous definitions have been eliminated + if( n.getKind()==APPLY_UF ){ + Node op = n.getOperator(); + if( d_macro_defs.find( op )!=d_macro_defs.end() ){ + if( d_macro_defs.find( oo )!=d_macro_defs.end() ){ + Trace("macros-warn") << "BAD DEFINITION for macro " << oo << " : " << d_macro_defs[oo] << std::endl; + }else{ + Trace("macros-warn") << "BAD ASSERTION " << oo << std::endl; + } + Trace("macros-warn") << " contains defined function " << op << "!!!" << std::endl; + } + } + for( unsigned i=0; i<n.getNumChildren(); i++ ){ + debugMacroDefinition( oo, n[i] ); + } +} + +void QuantifierMacros::finalizeDefinitions() { + bool doDefs = false; + if( Trace.isOn("macros-warn") ){ + doDefs = true; + } + if( options::incrementalSolving() || options::produceModels() || doDefs ){ + Trace("macros") << "Store as defined functions..." << std::endl; + //also store as defined functions + for( std::map< Node, Node >::iterator it = d_macro_defs.begin(); it != d_macro_defs.end(); ++it ){ + Trace("macros-def") << "Macro definition for " << it->first << " : " << it->second << std::endl; + Trace("macros-def") << " basis is : "; + std::vector< Node > nargs; + std::vector< Expr > args; + for( unsigned i=0; i<d_macro_basis[it->first].size(); i++ ){ + Node bv = NodeManager::currentNM()->mkBoundVar( d_macro_basis[it->first][i].getType() ); + Trace("macros-def") << d_macro_basis[it->first][i] << " "; + nargs.push_back( bv ); + args.push_back( bv.toExpr() ); + } + Trace("macros-def") << std::endl; + Node sbody = it->second.substitute( d_macro_basis[it->first].begin(), d_macro_basis[it->first].end(), nargs.begin(), nargs.end() ); + smt::currentSmtEngine()->defineFunction( it->first.toExpr(), args, sbody.toExpr() ); + + if( Trace.isOn("macros-warn") ){ + debugMacroDefinition( it->first, sbody ); + } + } + Trace("macros") << "done." << std::endl; + } +} + +void QuantifierMacros::addMacro( Node op, Node n, std::vector< Node >& opc ) { + Trace("macros") << "* " << n << " is a macro for " << op << ", #op contain = " << opc.size() << std::endl; + d_simplify_cache.clear(); + d_macro_defs[op] = n; + d_macro_defs_new[op] = n; + //substitute into all previous + std::vector< Node > dep_ops; + dep_ops.push_back( op ); + Trace("macros-debug") << "...substitute into " << d_macro_def_contains[op].size() << " previous definitions." << std::endl; + for( unsigned i=0; i<d_macro_def_contains[op].size(); i++ ){ + Node cop = d_macro_def_contains[op][i]; + Node def = d_macro_defs[cop]; + def = simplify( def ); + d_macro_defs[cop] = def; + if( d_macro_defs_new.find( cop )!=d_macro_defs_new.end() ){ + d_macro_defs_new[cop] = def; + } + dep_ops.push_back( cop ); + } + //store the contains op information + for( unsigned i=0; i<opc.size(); i++ ){ + for( unsigned j=0; j<dep_ops.size(); j++ ){ + Node dop = dep_ops[j]; + if( std::find( d_macro_def_contains[opc[i]].begin(), d_macro_def_contains[opc[i]].end(), dop )==d_macro_def_contains[opc[i]].end() ){ + d_macro_def_contains[opc[i]].push_back( dop ); + } + } + } +} + +} // passes +} // preprocessing +} // CVC4 diff --git a/src/preprocessing/passes/quantifier_macros.h b/src/preprocessing/passes/quantifier_macros.h new file mode 100644 index 000000000..092a62942 --- /dev/null +++ b/src/preprocessing/passes/quantifier_macros.h @@ -0,0 +1,89 @@ +/********************* */ +/*! \file quantifier_macros.h + ** \verbatim + ** Top contributors (to current version): + ** Andrew Reynolds + ** This file is part of the CVC4 project. + ** Copyright (c) 2009-2018 by the authors listed in the file AUTHORS + ** in the top-level source directory) and their institutional affiliations. + ** All rights reserved. See the file COPYING in the top-level source + ** directory for licensing information.\endverbatim + ** + ** \brief Pre-process step for detecting quantifier macro definitions + **/ + +#include "cvc4_private.h" + +#ifndef __CVC4__PREPROCESSING__PASSES__QUANTIFIER_MACROS_H +#define __CVC4__PREPROCESSING__PASSES__QUANTIFIER_MACROS_H + +#include <map> +#include <string> +#include <vector> +#include "expr/node.h" +#include "expr/type_node.h" +#include "preprocessing/preprocessing_pass.h" +#include "preprocessing/preprocessing_pass_context.h" + +namespace CVC4 { +namespace preprocessing { +namespace passes { + +class QuantifierMacros : public PreprocessingPass +{ + public: + QuantifierMacros(PreprocessingPassContext* preprocContext); + ~QuantifierMacros() {} + protected: + PreprocessingPassResult applyInternal( + AssertionPipeline* assertionsToPreprocess) override; + + private: + bool processAssertion(Node n); + bool isBoundVarApplyUf(Node n); + bool process(Node n, bool pol, std::vector<Node>& args, Node f); + bool containsBadOp(Node n, + Node op, + std::vector<Node>& opc, + std::map<Node, bool>& visited); + bool isMacroLiteral(Node n, bool pol); + bool isGroundUfTerm(Node f, Node n); + void getMacroCandidates(Node n, + std::vector<Node>& candidates, + std::map<Node, bool>& visited); + Node solveInEquality(Node n, Node lit); + bool getFreeVariables(Node n, + std::vector<Node>& v_quant, + std::vector<Node>& vars, + bool retOnly, + std::map<Node, bool>& visited); + bool getSubstitution(std::vector<Node>& v_quant, + std::map<Node, Node>& solved, + std::vector<Node>& vars, + std::vector<Node>& subs, + bool reqComplete); + void addMacro(Node op, Node n, std::vector<Node>& opc); + void debugMacroDefinition(Node oo, Node n); + bool simplify(std::vector<Node>& assertions, bool doRewrite = false); + Node simplify(Node n); + void finalizeDefinitions(); + void clearMaps(); + + // map from operators to macro basis terms + std::map<Node, std::vector<Node> > d_macro_basis; + // map from operators to macro definition + std::map<Node, Node> d_macro_defs; + std::map<Node, Node> d_macro_defs_new; + // operators to macro ops that contain them + std::map<Node, std::vector<Node> > d_macro_def_contains; + // simplify caches + std::map<Node, Node> d_simplify_cache; + std::map<Node, bool> d_quant_macros; + bool d_ground_macros; +}; + +} // passes +} // preprocessing +} // CVC4 + +#endif /*__CVC4__PREPROCESSING__PASSES__QUANTIFIER_MACROS_H */ |