// These transformations should never increase the size of the DAG.
ASTNode
STP::sizeReducing(ASTNode simplified_solved_InputToSAT, BVSolver* bvSolver, PropagateEqualities *pe)
{
simplified_solved_InputToSAT = pe->topLevel(simplified_solved_InputToSAT, arrayTransformer);
if (simp->hasUnappliedSubstitutions())
{
simplified_solved_InputToSAT = simp->applySubstitutionMap(simplified_solved_InputToSAT);
simp->haveAppliedSubstitutionMap();
bm->ASTNodeStats(pe_message.c_str(), simplified_solved_InputToSAT);
}
if (bm->UserFlags.isSet("enable-unconstrained", "1"))
{
// Remove unconstrained.
RemoveUnconstrained r1(*bm);
simplified_solved_InputToSAT = r1.topLevel(simplified_solved_InputToSAT, simp);
bm->ASTNodeStats(uc_message.c_str(), simplified_solved_InputToSAT);
}
if (bm->UserFlags.isSet("use-intervals", "1"))
{
EstablishIntervals intervals(*bm);
simplified_solved_InputToSAT = intervals.topLevel_unsignedIntervals(simplified_solved_InputToSAT);
bm->ASTNodeStats(int_message.c_str(), simplified_solved_InputToSAT);
}
if (bm->UserFlags.bitConstantProp_flag)
{
bm->GetRunTimes()->start(RunTimes::ConstantBitPropagation);
simplifier::constantBitP::ConstantBitPropagation cb(simp, bm->defaultNodeFactory, simplified_solved_InputToSAT);
simplified_solved_InputToSAT = cb.topLevelBothWays(simplified_solved_InputToSAT, true,false);
bm->GetRunTimes()->stop(RunTimes::ConstantBitPropagation);
if (cb.isUnsatisfiable())
simplified_solved_InputToSAT = bm->ASTFalse;
if (simp->hasUnappliedSubstitutions())
{
simplified_solved_InputToSAT = simp->applySubstitutionMap(simplified_solved_InputToSAT);
simp->haveAppliedSubstitutionMap();
}
bm->ASTNodeStats(cb_message.c_str(), simplified_solved_InputToSAT);
}
// Find pure literals.
if (bm->UserFlags.isSet("pure-literals", "1"))
{
FindPureLiterals fpl;
bool changed = fpl.topLevel(simplified_solved_InputToSAT, simp, bm);
if (changed)
{
simplified_solved_InputToSAT = simp->applySubstitutionMap(simplified_solved_InputToSAT);
simp->haveAppliedSubstitutionMap();
bm->ASTNodeStats(pl_message.c_str() , simplified_solved_InputToSAT);
}
}
if (bm->UserFlags.isSet("always-true", "0"))
{
AlwaysTrue always (simp,bm,bm->defaultNodeFactory);
simplified_solved_InputToSAT = always.topLevel(simplified_solved_InputToSAT);
bm->ASTNodeStats("After removing always true: ", simplified_solved_InputToSAT);
}
if (bm->UserFlags.wordlevel_solve_flag && bm->UserFlags.optimize_flag)
{
simplified_solved_InputToSAT = bvSolver->TopLevelBVSolve(simplified_solved_InputToSAT, false);
bm->ASTNodeStats(bitvec_message.c_str(), simplified_solved_InputToSAT);
}
return simplified_solved_InputToSAT;
}
//Acceps a query, calls the SAT solver and generates Valid/InValid.
//if returned 0 then input is INVALID if returned 1 then input is
//VALID if returned 2 then UNDECIDED
SOLVER_RETURN_TYPE
STP::TopLevelSTPAux(SATSolver& NewSolver, const ASTNode& original_input)
{
bm->ASTNodeStats("input asserts and query: ", original_input);
DifficultyScore difficulty;
if (bm->UserFlags.stats_flag)
cerr << "Difficulty Initially:" << difficulty.score(original_input) << endl;
// A heap object so I can easily control its lifetime.
std::auto_ptr<BVSolver> bvSolver(new BVSolver(bm, simp));
std::auto_ptr<PropagateEqualities> pe (new PropagateEqualities(simp,bm->defaultNodeFactory,bm));
ASTNode simplified_solved_InputToSAT = original_input;
// If the number of array reads is small. We rewrite them through.
// The bit-vector simplifications are more thorough than the array simplifications. For example,
// we don't currently do unconstrained elimination on arrays--- but we do for bit-vectors.
// A better way to do this would be to estimate the number of axioms introduced.
// TODO: I chose the number of reads we perform this operation at randomly.
bool removed = false;
if (((bm->UserFlags.ackermannisation && numberOfReadsLessThan(simplified_solved_InputToSAT,50)) || bm->UserFlags.isSet("upfront-ack", "0"))
|| numberOfReadsLessThan(simplified_solved_InputToSAT,10)
)
{
// If the number of axioms that would be added it small. Remove them.
bm->UserFlags.ackermannisation = true;
simplified_solved_InputToSAT = arrayTransformer->TransformFormula_TopLevel(simplified_solved_InputToSAT);
if (bm->UserFlags.stats_flag)
cerr << "Have removed array operations" << endl;
removed = true;
}
const bool arrayops = containsArrayOps(simplified_solved_InputToSAT);
if (removed)
assert(!arrayops);
// Run size reducing just once.
simplified_solved_InputToSAT = sizeReducing(simplified_solved_InputToSAT, bvSolver.get(),pe.get());
unsigned initial_difficulty_score = difficulty.score(simplified_solved_InputToSAT);
int bitblasted_difficulty = -1;
// Fixed point it if it's not too difficult.
// Currently we discards all the state each time sizeReducing is called,
// so it's expensive to call.
if ((!arrayops && initial_difficulty_score < 1000000) || bm->UserFlags.isSet("preserving-fixedpoint", "0"))
simplified_solved_InputToSAT = callSizeReducing(simplified_solved_InputToSAT, bvSolver.get(),pe.get(), initial_difficulty_score, bitblasted_difficulty);
if ((!arrayops || bm->UserFlags.isSet("array-difficulty-reversion", "1")))
{
initial_difficulty_score = difficulty.score(simplified_solved_InputToSAT);
}
if (bitblasted_difficulty != -1 && bm->UserFlags.stats_flag)
std::cout << "Initial Bitblasted size:" << bitblasted_difficulty << endl;
if (bm->UserFlags.stats_flag)
std::cout << "Difficulty After Size reducing:" << initial_difficulty_score << endl;
// So we can delete the object and release all the hash-buckets storage.
std::auto_ptr<Revert_to> revert(new Revert_to());
if ((!arrayops || bm->UserFlags.isSet("array-difficulty-reversion", "1")))
{
revert->initialSolverMap.insert(simp->Return_SolverMap()->begin(), simp->Return_SolverMap()->end());
revert->backup_arrayToIndexToRead.insert(arrayTransformer->arrayToIndexToRead.begin(),arrayTransformer->arrayToIndexToRead.end());
revert->toRevertTo = simplified_solved_InputToSAT;
}
ASTNode inputToSAT;
//round of substitution, solving, and simplification. ensures that
//DAG is minimized as much as possibly, and ideally should
//garuntee that all liketerms in BVPLUSes have been combined.
bm->SimplifyWrites_InPlace_Flag = false;
//bm->Begin_RemoveWrites = false;
//bm->start_abstracting = false;
bm->TermsAlreadySeenMap_Clear();
do
{
inputToSAT = simplified_solved_InputToSAT;
if (bm->soft_timeout_expired)
return SOLVER_TIMEOUT;
if (bm->UserFlags.optimize_flag)
{
simplified_solved_InputToSAT = pe->topLevel(simplified_solved_InputToSAT, arrayTransformer);
// Imagine:
// The simplifier simplifies (0 + T) to T
// Then bvsolve introduces (0 + T)
// Then CreateSubstitutionMap decides T maps to a constant, but leaving another (0+T).
// When we go to simplify (0 + T) will still be in the simplify cache, so will be mapped to T.
// But it shouldn't be T, it should be a constant.
// Applying the substitution map fixes this case.
//
if (simp->hasUnappliedSubstitutions())
{
simplified_solved_InputToSAT = simp->applySubstitutionMap(simplified_solved_InputToSAT);
simp->haveAppliedSubstitutionMap();
}
bm->ASTNodeStats(pe_message.c_str(), simplified_solved_InputToSAT);
simplified_solved_InputToSAT = simp->SimplifyFormula_TopLevel(simplified_solved_InputToSAT, false);
bm->ASTNodeStats(size_inc_message.c_str(), simplified_solved_InputToSAT);
}
if (bm->UserFlags.wordlevel_solve_flag && bm->UserFlags.optimize_flag)
{
simplified_solved_InputToSAT = bvSolver->TopLevelBVSolve(simplified_solved_InputToSAT);
bm->ASTNodeStats(bitvec_message.c_str(), simplified_solved_InputToSAT);
}
}
while (inputToSAT != simplified_solved_InputToSAT);
if (bm->UserFlags.bitConstantProp_flag)
{
bm->GetRunTimes()->start(RunTimes::ConstantBitPropagation);
simplifier::constantBitP::ConstantBitPropagation cb(simp, bm->defaultNodeFactory, simplified_solved_InputToSAT);
simplified_solved_InputToSAT = cb.topLevelBothWays(simplified_solved_InputToSAT);
bm->GetRunTimes()->stop(RunTimes::ConstantBitPropagation);
if (cb.isUnsatisfiable())
simplified_solved_InputToSAT = bm->ASTFalse;
bm->ASTNodeStats(cb_message.c_str(), simplified_solved_InputToSAT);
}
if (bm->UserFlags.isSet("use-intervals", "1"))
{
EstablishIntervals intervals(*bm);
simplified_solved_InputToSAT = intervals.topLevel_unsignedIntervals(simplified_solved_InputToSAT);
bm->ASTNodeStats(int_message.c_str(), simplified_solved_InputToSAT);
}
// Find pure literals.
if (bm->UserFlags.isSet("pure-literals", "1"))
{
FindPureLiterals fpl;
bool changed = fpl.topLevel(simplified_solved_InputToSAT, simp, bm);
if (changed)
{
simplified_solved_InputToSAT = simp->applySubstitutionMap(simplified_solved_InputToSAT);
simp->haveAppliedSubstitutionMap();
bm->ASTNodeStats(pl_message.c_str(), simplified_solved_InputToSAT);
}
}
if (bm->soft_timeout_expired)
return SOLVER_TIMEOUT;
// Simplify using Ite context
if (bm->UserFlags.optimize_flag && bm->UserFlags.isSet("ite-context", "0"))
{
UseITEContext iteC(bm);
simplified_solved_InputToSAT = iteC.topLevel(simplified_solved_InputToSAT);
bm->ASTNodeStats("After ITE Context: ", simplified_solved_InputToSAT);
}
if (bm->UserFlags.isSet("aig-core-simplify", "0"))
{
AIGSimplifyPropositionalCore aigRR(bm);
simplified_solved_InputToSAT = aigRR.topLevel(simplified_solved_InputToSAT);
bm->ASTNodeStats("After AIG Core: ", simplified_solved_InputToSAT);
}
#if 0
bm->ASTNodeStats("Before SimplifyWrites_Inplace begins: ", simplified_solved_InputToSAT);
bm->SimplifyWrites_InPlace_Flag = true;
bm->Begin_RemoveWrites = false;
bm->start_abstracting = false;
bm->TermsAlreadySeenMap_Clear();
do
{
inputToSAT = simplified_solved_InputToSAT;
if (bm->UserFlags.optimize_flag)
{
simplified_solved_InputToSAT = pe->topLevel(simplified_solved_InputToSAT, arrayTransformer);
if (simp->hasUnappliedSubstitutions())
{
simplified_solved_InputToSAT = simp->applySubstitutionMap(simplified_solved_InputToSAT);
simp->haveAppliedSubstitutionMap();
}
bm->ASTNodeStats(pe->message.c_str(), simplified_solved_InputToSAT);
simplified_solved_InputToSAT = simp->SimplifyFormula_TopLevel(simplified_solved_InputToSAT, false);
bm->ASTNodeStats("after simplification: ", simplified_solved_InputToSAT);
if (bm->UserFlags.isSet("always-true", "0"))
{
SimplifyingNodeFactory nf(*(bm->hashingNodeFactory), *bm);
AlwaysTrue always (simp,bm,&nf);
simplified_solved_InputToSAT = always.topLevel(simplified_solved_InputToSAT);
bm->ASTNodeStats("After removing always true: ", simplified_solved_InputToSAT);
}
}
// The word level solver uses the simplifier to apply the rewrites it makes,
// without optimisations enabled. It will enter infinite loops on some input.
// Instead it could use the apply function of the substitution map, but it
// doesn't yet...
if (bm->UserFlags.wordlevel_solve_flag && bm->UserFlags.optimize_flag)
{
simplified_solved_InputToSAT = bvSolver->TopLevelBVSolve(simplified_solved_InputToSAT);
bm->ASTNodeStats("after solving: ", simplified_solved_InputToSAT);
}
}
while (inputToSAT != simplified_solved_InputToSAT);
bm->ASTNodeStats("After SimplifyWrites_Inplace: ", simplified_solved_InputToSAT);
#endif
if (bm->UserFlags.isSet("enable-unconstrained", "1"))
{
// Remove unconstrained.
RemoveUnconstrained r(*bm);
simplified_solved_InputToSAT = r.topLevel(simplified_solved_InputToSAT, simp);
bm->ASTNodeStats(uc_message.c_str(), simplified_solved_InputToSAT);
}
bm->TermsAlreadySeenMap_Clear();
//bm->start_abstracting = false;
bm->SimplifyWrites_InPlace_Flag = false;
//bm->Begin_RemoveWrites = false;
long final_difficulty_score = difficulty.score(simplified_solved_InputToSAT);
bool worse= false;
if (final_difficulty_score > 1.1 * initial_difficulty_score)
worse = true;
// It's of course very wasteful to do this! Later I'll make it reuse the work..
// We bit-blast again, in order to throw it away, so that we can measure whether
// the number of AIG nodes is smaller. The difficulty score is sometimes completely
// wrong, the sage-app7 are the motivating examples. The other way to improve it would
// be to fix the difficulty scorer!
if (!worse && (bitblasted_difficulty != -1))
{
BBNodeManagerAIG bbnm;
BitBlaster<BBNodeAIG, BBNodeManagerAIG> bb(&bbnm, simp, bm->defaultNodeFactory , &(bm->UserFlags));
bb.BBForm(simplified_solved_InputToSAT);
int newBB= bbnm.totalNumberOfNodes();
if (bm->UserFlags.stats_flag)
cerr << "Final BB Size:" << newBB << endl;
if (bitblasted_difficulty < newBB)
worse = true;
}
if (bm->UserFlags.stats_flag)
{
cerr << "Initial Difficulty Score:" << initial_difficulty_score << endl;
cerr << "Final Difficulty Score:" << final_difficulty_score << endl;
}
bool optimize_enabled = bm->UserFlags.optimize_flag;
if (worse &&
(!arrayops || bm->UserFlags.isSet("array-difficulty-reversion", "1")) &&
bm->UserFlags.isSet("difficulty-reversion", "1"))
{
// If the simplified problem is harder, than the
// initial problem we revert back to the initial
// problem.
if (bm->UserFlags.stats_flag)
cerr << "simplification made the problem harder, reverting." << endl;
simplified_solved_InputToSAT = revert->toRevertTo;
// I do this to clear the substitution/solver map.
// Not sure what would happen if it contained simplifications
// that haven't been applied.
simp->ClearAllTables();
simp->Return_SolverMap()->insert(revert->initialSolverMap.begin(), revert->initialSolverMap.end());
revert->initialSolverMap.clear();
// Copy back what we knew about arrays at the start..
arrayTransformer->arrayToIndexToRead.clear();
arrayTransformer->arrayToIndexToRead.insert(revert->backup_arrayToIndexToRead.begin(), revert->backup_arrayToIndexToRead.end());
// The arrayTransformer calls simplify. We don't want
// it to put back in all the bad simplifications.
bm->UserFlags.optimize_flag = false;
}
revert.reset(NULL);
simplified_solved_InputToSAT = arrayTransformer->TransformFormula_TopLevel(simplified_solved_InputToSAT);
bm->ASTNodeStats("after transformation: ", simplified_solved_InputToSAT);
bm->TermsAlreadySeenMap_Clear();
bm->UserFlags.optimize_flag = optimize_enabled;
SOLVER_RETURN_TYPE res;
if (!bm->UserFlags.ackermannisation)
{
bm->counterexample_checking_during_refinement = true;
}
// We are about to solve. Clear out all the memory associated with caches
// that we won't need again.
simp->ClearCaches();
simp->haveAppliedSubstitutionMap();
bm->ClearAllTables();
// Deleting it clears out all the buckets associated with hashmaps etc. too.
bvSolver.reset(NULL);
pe.reset(NULL);
if (bm->UserFlags.stats_flag)
simp->printCacheStatus();
const bool maybeRefinement = arrayops && !bm->UserFlags.ackermannisation;
simplifier::constantBitP::ConstantBitPropagation* cb = NULL;
std::auto_ptr<simplifier::constantBitP::ConstantBitPropagation> cleaner;
if (bm->UserFlags.bitConstantProp_flag)
{
bm->GetRunTimes()->start(RunTimes::ConstantBitPropagation);
cb = new simplifier::constantBitP::ConstantBitPropagation(simp, bm->defaultNodeFactory,
simplified_solved_InputToSAT);
cleaner.reset(cb);
bm->GetRunTimes()->stop(RunTimes::ConstantBitPropagation);
bm->ASTNodeStats(cb_message.c_str(), simplified_solved_InputToSAT);
if (cb->isUnsatisfiable())
simplified_solved_InputToSAT = bm->ASTFalse;
}
ToSATAIG toSATAIG(bm, cb, arrayTransformer);
ToSATBase* satBase = bm->UserFlags.isSet("traditional-cnf", "0") ? tosat : &toSATAIG;
if (bm->soft_timeout_expired)
return SOLVER_TIMEOUT;
// If it doesn't contain array operations, use ABC's CNF generation.
res = Ctr_Example->CallSAT_ResultCheck(NewSolver, simplified_solved_InputToSAT, original_input, satBase,
maybeRefinement);
if (bm->soft_timeout_expired)
{
if (toSATAIG.cbIsDestructed())
cleaner.release();
return SOLVER_TIMEOUT;
}
if (SOLVER_UNDECIDED != res)
{
// If the aig converter knows that it is never going to be called again,
// it deletes the constant bit stuff before calling the SAT solver.
if (toSATAIG.cbIsDestructed())
cleaner.release();
CountersAndStats("print_func_stats", bm);
return res;
}
assert(arrayops); // should only go to abstraction refinement if there are array ops.
assert(!bm->UserFlags.ackermannisation); // Refinement must be enabled too.
assert (bm->UserFlags.solver_to_use != UserDefinedFlags::MINISAT_PROPAGATORS); // The array solver shouldn't have returned undecided..
res = Ctr_Example->SATBased_ArrayReadRefinement(NewSolver, simplified_solved_InputToSAT, original_input, satBase);
if (SOLVER_UNDECIDED != res)
{
if (toSATAIG.cbIsDestructed())
cleaner.release();
CountersAndStats("print_func_stats", bm);
return res;
}
#if 0
res = Ctr_Example->SATBased_ArrayWriteRefinement(NewSolver, original_input, satBase);
if (SOLVER_UNDECIDED != res)
{
if (toSATAIG.cbIsDestructed())
cleaner.release();
CountersAndStats("print_func_stats", bm);
return res;
}
res = Ctr_Example->SATBased_ArrayReadRefinement(NewSolver, simplified_solved_InputToSAT, original_input, satBase);
if (SOLVER_UNDECIDED != res)
{
if (toSATAIG.cbIsDestructed())
cleaner.release();
CountersAndStats("print_func_stats", bm);
return res;
}
#endif
FatalError("TopLevelSTPAux: reached the end without proper conclusion:"
"either a divide by zero in the input or a bug in STP");
//bogus return to make the compiler shut up
return SOLVER_ERROR;
} //End of TopLevelSTPAux
//Acceps a query, calls the SAT solver and generates Valid/InValid.
//if returned 0 then input is INVALID if returned 1 then input is
//VALID if returned 2 then UNDECIDED
SOLVER_RETURN_TYPE
STP::TopLevelSTPAux(SATSolver& NewSolver, const ASTNode& modified_input, const ASTNode& original_input)
{
ASTNode inputToSAT = modified_input;
ASTNode orig_input = original_input;
bm->ASTNodeStats("input asserts and query: ", inputToSAT);
ASTNode simplified_solved_InputToSAT = inputToSAT;
const bool arrayops = containsArrayOps(original_input);
DifficultyScore difficulty;
if (bm->UserFlags.stats_flag)
cerr << "Difficulty Initially:" << difficulty.score(original_input) << endl;
// A heap object so I can easily control its lifetime.
BVSolver* bvSolver = new BVSolver(bm, simp);
simplified_solved_InputToSAT = sizeReducing(inputToSAT, bvSolver);
unsigned initial_difficulty_score = difficulty.score(simplified_solved_InputToSAT);
// Fixed point it if it's not too difficult.
// Currently we discards all the state each time sizeReducing is called,
// so it's expensive to call.
if (!arrayops && initial_difficulty_score < 1000000)
{
simplified_solved_InputToSAT = callSizeReducing(simplified_solved_InputToSAT, bvSolver, initial_difficulty_score);
initial_difficulty_score = difficulty.score(simplified_solved_InputToSAT);
}
if (bm->UserFlags.stats_flag)
cout << "Difficulty After Size reducing:" << initial_difficulty_score << endl;
// Copy the solver map incase we need to revert.
ASTNodeMap initialSolverMap;
ASTNode toRevertTo;
if (!arrayops) // we don't revert for Array problems yet, so don't copy it.
{
initialSolverMap.insert(simp->Return_SolverMap()->begin(), simp->Return_SolverMap()->end());
toRevertTo = simplified_solved_InputToSAT;
}
//round of substitution, solving, and simplification. ensures that
//DAG is minimized as much as possibly, and ideally should
//garuntee that all liketerms in BVPLUSes have been combined.
bm->SimplifyWrites_InPlace_Flag = false;
bm->Begin_RemoveWrites = false;
bm->start_abstracting = false;
bm->TermsAlreadySeenMap_Clear();
do
{
inputToSAT = simplified_solved_InputToSAT;
if (bm->UserFlags.optimize_flag)
{
simplified_solved_InputToSAT = simp->CreateSubstitutionMap(simplified_solved_InputToSAT, arrayTransformer);
// Imagine:
// The simplifier simplifies (0 + T) to T
// Then bvsolve introduces (0 + T)
// Then CreateSubstitutionMap decides T maps to a constant, but leaving another (0+T).
// When we go to simplify (0 + T) will still be in the simplify cache, so will be mapped to T.
// But it shouldn't be T, it should be a constant.
// Applying the substitution map fixes this case.
//
if (simp->hasUnappliedSubstitutions())
{
simplified_solved_InputToSAT = simp->applySubstitutionMap(simplified_solved_InputToSAT);
simp->haveAppliedSubstitutionMap();
}
bm->ASTNodeStats("after pure substitution: ", simplified_solved_InputToSAT);
simplified_solved_InputToSAT = simp->SimplifyFormula_TopLevel(simplified_solved_InputToSAT, false);
bm->ASTNodeStats("after simplification: ", simplified_solved_InputToSAT);
}
if (bm->UserFlags.wordlevel_solve_flag && bm->UserFlags.optimize_flag)
{
simplified_solved_InputToSAT = bvSolver->TopLevelBVSolve(simplified_solved_InputToSAT);
bm->ASTNodeStats("after solving: ", simplified_solved_InputToSAT);
}
}
while (inputToSAT != simplified_solved_InputToSAT);
if (bm->UserFlags.bitConstantProp_flag)
{
bm->GetRunTimes()->start(RunTimes::ConstantBitPropagation);
SimplifyingNodeFactory nf(*(bm->hashingNodeFactory), *bm);
simplifier::constantBitP::ConstantBitPropagation cb(simp, &nf, simplified_solved_InputToSAT);
simplified_solved_InputToSAT = cb.topLevelBothWays(simplified_solved_InputToSAT);
bm->GetRunTimes()->stop(RunTimes::ConstantBitPropagation);
if (cb.isUnsatisfiable())
simplified_solved_InputToSAT = bm->ASTFalse;
bm->ASTNodeStats("After Constant Bit Propagation begins: ", simplified_solved_InputToSAT);
}
if (bm->UserFlags.isSet("use-intervals", "1"))
{
EstablishIntervals intervals(*bm);
simplified_solved_InputToSAT = intervals.topLevel_unsignedIntervals(simplified_solved_InputToSAT);
bm->ASTNodeStats("After Establishing Intervals: ", simplified_solved_InputToSAT);
}
// Find pure literals.
if (bm->UserFlags.isSet("pure-literals", "1"))
{
FindPureLiterals fpl;
bool changed = fpl.topLevel(simplified_solved_InputToSAT, simp, bm);
if (changed)
{
simplified_solved_InputToSAT = simp->applySubstitutionMap(simplified_solved_InputToSAT);
simp->haveAppliedSubstitutionMap();
bm->ASTNodeStats("After Pure Literals: ", simplified_solved_InputToSAT);
}
}
// Simplify using Ite context
if (bm->UserFlags.optimize_flag && bm->UserFlags.isSet("ite-context", "0"))
{
UseITEContext iteC(bm);
simplified_solved_InputToSAT = iteC.topLevel(simplified_solved_InputToSAT);
bm->ASTNodeStats("After ITE Context: ", simplified_solved_InputToSAT);
}
if (bm->UserFlags.isSet("aig-core-simplify", "0"))
{
AIGSimplifyPropositionalCore aigRR(bm);
simplified_solved_InputToSAT = aigRR.topLevel(simplified_solved_InputToSAT);
bm->ASTNodeStats("After AIG Core: ", simplified_solved_InputToSAT);
}
bm->ASTNodeStats("Before SimplifyWrites_Inplace begins: ", simplified_solved_InputToSAT);
bm->SimplifyWrites_InPlace_Flag = true;
bm->Begin_RemoveWrites = false;
bm->start_abstracting = false;
bm->TermsAlreadySeenMap_Clear();
do
{
inputToSAT = simplified_solved_InputToSAT;
if (bm->UserFlags.optimize_flag)
{
simplified_solved_InputToSAT = simp->CreateSubstitutionMap(simplified_solved_InputToSAT, arrayTransformer);
if (simp->hasUnappliedSubstitutions())
{
simplified_solved_InputToSAT = simp->applySubstitutionMap(simplified_solved_InputToSAT);
simp->haveAppliedSubstitutionMap();
}
bm->ASTNodeStats("after pure substitution: ", simplified_solved_InputToSAT);
simplified_solved_InputToSAT = simp->SimplifyFormula_TopLevel(simplified_solved_InputToSAT, false);
bm->ASTNodeStats("after simplification: ", simplified_solved_InputToSAT);
if (bm->UserFlags.isSet("always-true", "0"))
{
SimplifyingNodeFactory nf(*(bm->hashingNodeFactory), *bm);
AlwaysTrue always (simp,bm,&nf);
simplified_solved_InputToSAT = always.topLevel(simplified_solved_InputToSAT);
bm->ASTNodeStats("After removing always true: ", simplified_solved_InputToSAT);
}
}
// The word level solver uses the simplifier to apply the rewrites it makes,
// without optimisations enabled. It will enter infinite loops on some input.
// Instead it could use the apply function of the substitution map, but it
// doesn't yet...
if (bm->UserFlags.wordlevel_solve_flag && bm->UserFlags.optimize_flag)
{
simplified_solved_InputToSAT = bvSolver->TopLevelBVSolve(simplified_solved_InputToSAT);
bm->ASTNodeStats("after solving: ", simplified_solved_InputToSAT);
}
}
while (inputToSAT != simplified_solved_InputToSAT);
bm->ASTNodeStats("After SimplifyWrites_Inplace: ", simplified_solved_InputToSAT);
if (bm->UserFlags.isSet("enable-unconstrained", "1"))
{
// Remove unconstrained.
RemoveUnconstrained r(*bm);
simplified_solved_InputToSAT = r.topLevel(simplified_solved_InputToSAT, simp);
bm->ASTNodeStats("After Unconstrained Remove begins: ", simplified_solved_InputToSAT);
}
bm->TermsAlreadySeenMap_Clear();
bm->start_abstracting = false;
bm->SimplifyWrites_InPlace_Flag = false;
bm->Begin_RemoveWrites = false;
long final_difficulty_score = difficulty.score(simplified_solved_InputToSAT);
if (bm->UserFlags.stats_flag)
{
cerr << "Initial Difficulty Score:" << initial_difficulty_score << endl;
cerr << "Final Difficulty Score:" << final_difficulty_score << endl;
}
bool optimize_enabled = bm->UserFlags.optimize_flag;
if (final_difficulty_score > 1.1 * initial_difficulty_score && !arrayops && bm->UserFlags.isSet(
"difficulty-reversion", "1"))
{
// If the simplified problem is harder, than the
// initial problem we revert back to the initial
// problem.
if (bm->UserFlags.stats_flag)
cerr << "simplification made the problem harder, reverting." << endl;
simplified_solved_InputToSAT = toRevertTo;
// I do this to clear the substitution/solver map.
// Not sure what would happen if it contained simplifications
// that haven't been applied.
simp->ClearAllTables();
simp->Return_SolverMap()->insert(initialSolverMap.begin(), initialSolverMap.end());
initialSolverMap.clear();
// The arrayTransformer calls simplify. We don't want
// it to put back in all the bad simplifications.
bm->UserFlags.optimize_flag = false;
}
simplified_solved_InputToSAT = arrayTransformer->TransformFormula_TopLevel(simplified_solved_InputToSAT);
bm->ASTNodeStats("after transformation: ", simplified_solved_InputToSAT);
bm->TermsAlreadySeenMap_Clear();
bm->UserFlags.optimize_flag = optimize_enabled;
SOLVER_RETURN_TYPE res;
if (bm->UserFlags.arrayread_refinement_flag)
{
bm->counterexample_checking_during_refinement = true;
}
// We are about to solve. Clear out all the memory associated with caches
// that we won't need again.
simp->ClearCaches();
simp->haveAppliedSubstitutionMap();
bm->ClearAllTables();
// Deleting it clears out all the buckets associated with hashmaps etc. too.
delete bvSolver;
bvSolver = NULL;
if (bm->UserFlags.stats_flag)
simp->printCacheStatus();
const bool maybeRefinement = arrayops && bm->UserFlags.arrayread_refinement_flag;
simplifier::constantBitP::ConstantBitPropagation* cb = NULL;
std::auto_ptr<simplifier::constantBitP::ConstantBitPropagation> cleaner;
if (bm->UserFlags.bitConstantProp_flag)
{
bm->ASTNodeStats("Before Constant Bit Propagation begins: ", simplified_solved_InputToSAT);
bm->GetRunTimes()->start(RunTimes::ConstantBitPropagation);
cb = new simplifier::constantBitP::ConstantBitPropagation(simp, bm->defaultNodeFactory,
simplified_solved_InputToSAT);
cleaner.reset(cb);
bm->GetRunTimes()->stop(RunTimes::ConstantBitPropagation);
if (cb->isUnsatisfiable())
simplified_solved_InputToSAT = bm->ASTFalse;
}
ToSATAIG toSATAIG(bm, cb);
toSATAIG.setArrayTransformer(arrayTransformer);
ToSATBase* satBase = bm->UserFlags.isSet("traditional-cnf", "0") ? tosat : ((ToSAT*) &toSATAIG) ;
// If it doesn't contain array operations, use ABC's CNF generation.
res = Ctr_Example->CallSAT_ResultCheck(NewSolver, simplified_solved_InputToSAT, orig_input, satBase,
maybeRefinement);
if (SOLVER_UNDECIDED != res)
{
// If the aig converter knows that it is never going to be called again,
// it deletes the constant bit stuff before calling the SAT solver.
if (toSATAIG.cbIsDestructed())
cleaner.release();
CountersAndStats("print_func_stats", bm);
return res;
}
assert(arrayops); // should only go to abstraction refinement if there are array ops.
assert(bm->UserFlags.arrayread_refinement_flag); // Refinement must be enabled too.
// Unfortunately how I implemented the incremental CNF generator in ABC means that
// cryptominisat and simplifying minisat may simplify away variables that we later need.
res = Ctr_Example->SATBased_ArrayReadRefinement(NewSolver, simplified_solved_InputToSAT, orig_input, satBase);
if (SOLVER_UNDECIDED != res)
{
if (toSATAIG.cbIsDestructed())
cleaner.release();
CountersAndStats("print_func_stats", bm);
return res;
}
res = Ctr_Example->SATBased_ArrayWriteRefinement(NewSolver, orig_input, satBase);
if (SOLVER_UNDECIDED != res)
{
if (toSATAIG.cbIsDestructed())
cleaner.release();
CountersAndStats("print_func_stats", bm);
return res;
}
res = Ctr_Example->SATBased_ArrayReadRefinement(NewSolver, simplified_solved_InputToSAT, orig_input, satBase);
if (SOLVER_UNDECIDED != res)
{
if (toSATAIG.cbIsDestructed())
cleaner.release();
CountersAndStats("print_func_stats", bm);
return res;
}
// if (!bm->UserFlags.num_absrefine_flag)
{
FatalError("TopLevelSTPAux: reached the end without proper conclusion:"
"either a divide by zero in the input or a bug in STP");
//bogus return to make the compiler shut up
return SOLVER_ERROR;
}
// else
{
// return res;
}
} //End of TopLevelSTPAux