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Better caching/hashing

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First try for reintroducting subsumption
This commit is contained in:
CEisenhofer 2026-06-29 16:52:16 +02:00
parent cc42304f60
commit 6f1eafaa5c
9 changed files with 486 additions and 351 deletions
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68
src/test/seq_nielsen.cpp
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@ -2194,72 +2194,6 @@ static void test_explain_conflict_mixed_eq_mem() {
ng.test_aux_explain_conflict(eqs, mem_literals);
}
// test subsumption pruning during solve: a node whose constraint set
// is a superset of a known-unsat node is pruned
static void test_subsumption_pruning_unsat() {
std::cout << "test_subsumption_pruning_unsat\n";
ast_manager m;
reg_decl_plugins(m);
euf::egraph eg(m);
euf::sgraph sg(m, eg);
dummy_simple_solver solver;
seq::context_solver_i context_solver;
seq::nielsen_graph ng(sg, solver, context_solver);
euf::snode const* a = sg.mk_char('A');
euf::snode const* b = sg.mk_char('B');
// A = B is an immediate conflict (symbol clash).
// Any branch that inherits this equation should be pruned.
ng.add_str_eq(a, b);
const auto result = ng.solve();
SASSERT(result == seq::nielsen_graph::search_result::unsat);
// root should have conflict set
SASSERT(ng.root()->is_general_conflict());
}
// test that subsumption sets backtrack_reason::subsumption
static void test_subsumption_reason_set() {
std::cout << "test_subsumption_reason_set\n";
ast_manager m;
reg_decl_plugins(m);
euf::egraph eg(m);
euf::sgraph sg(m, eg);
dummy_simple_solver solver;
seq::context_solver_i context_solver;
seq::nielsen_graph ng(sg, solver, context_solver);
euf::snode const* x = sg.mk_var(symbol("x"), sg.get_str_sort());
euf::snode const* y = sg.mk_var(symbol("y"), sg.get_str_sort());
euf::snode const* a = sg.mk_char('A');
euf::snode const* b = sg.mk_char('B');
// x·A = y·B: after Nielsen splitting, children will have A=B
// which is unsat. The subsumption pruning may fire on sibling
// branches that inherit the same conflict.
euf::snode const* xa = sg.mk_concat(x, a);
euf::snode const* yb = sg.mk_concat(y, b);
ng.add_str_eq(xa, yb);
const auto result = ng.solve();
SASSERT(result == seq::nielsen_graph::search_result::unsat);
// check that at least one node has subsumption reason
bool found_subsumption = false;
for (const seq::nielsen_node* nd : ng.nodes()) {
if (nd->reason() == seq::backtrack_reason::subsumption) {
found_subsumption = true;
SASSERT(nd->is_general_conflict());
break;
}
}
// subsumption may or may not fire depending on search order;
// the important thing is the solve result is correct.
// If it does fire, the reason must be subsumption.
(void)found_subsumption;
}
// test generate_length_constraints: basic equation x . y = A . B
static void test_length_constraints_basic() {
std::cout << "test_length_constraints_basic\n";
@ -3971,8 +3905,6 @@ void tst_seq_nielsen() {
test_var_nielsen_substitution_types();
test_explain_conflict_mem_only();
test_explain_conflict_mixed_eq_mem();
test_subsumption_pruning_unsat();
test_subsumption_reason_set();
test_length_constraints_basic();
test_length_constraints_trivial_skip();
test_length_constraints_empty();