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This commit is contained in:
Nikolaj Bjorner 2016-02-28 17:05:52 -08:00
commit 7656adc483
3 changed files with 57 additions and 39 deletions

View file

@ -152,20 +152,27 @@ std::ostream& operator<<(std::ostream& o, const interval& I) {
}
struct undo_bound {
expr* e;
interval b;
bool fresh;
undo_bound(expr* e, const interval& b, bool fresh) : e(e), b(b), fresh(fresh) {}
};
class bv_bounds_simplifier : public ctx_simplify_tactic::simplifier {
typedef obj_map<expr, interval> map;
typedef obj_map<expr, bool> expr_set;
typedef obj_map<expr, expr_set*> expr_list_map;
ast_manager& m;
params_ref m_params;
bool m_propagate_eq;
bv_util m_bv;
vector<map> m_scopes;
map *m_bound;
expr_list_map m_expr_vars;
ast_manager& m;
params_ref m_params;
bool m_propagate_eq;
bv_util m_bv;
vector<undo_bound> m_scopes;
map m_bound;
expr_list_map m_expr_vars;
bool is_bound(expr *e, expr*& v, interval& b) {
bool is_bound(expr *e, expr*& v, interval& b) const {
rational n;
expr *lhs, *rhs;
unsigned sz;
@ -253,8 +260,6 @@ class bv_bounds_simplifier : public ctx_simplify_tactic::simplifier {
public:
bv_bounds_simplifier(ast_manager& m, params_ref const& p) : m(m), m_params(p), m_bv(m) {
m_scopes.push_back(map());
m_bound = &m_scopes.back();
updt_params(p);
}
@ -285,10 +290,21 @@ public:
if (sign)
VERIFY(b.negate(b));
push();
TRACE("bv", tout << (sign?"(not ":"") << mk_pp(t, m) << (sign ? ")" : "") << ": " << mk_pp(t1, m) << " in " << b << "\n";);
interval& r = m_bound->insert_if_not_there2(t1, b)->get_data().m_value;
return r.intersect(b, r);
map::obj_map_entry* e = m_bound.find_core(t1);
if (e) {
interval& old = e->get_data().m_value;
interval intr;
if (!old.intersect(b, intr))
return false;
if (old == intr)
return true;
m_scopes.insert(undo_bound(t1, old, false));
old = intr;
} else {
m_bound.insert(t1, b);
m_scopes.insert(undo_bound(t1, interval(), true));
}
}
return true;
}
@ -297,7 +313,7 @@ public:
expr* t1;
interval b;
if (m_bound->find(t, b) && b.is_singleton()) {
if (m_bound.find(t, b) && b.is_singleton()) {
result = m_bv.mk_numeral(b.l, m_bv.get_bv_size(t));
return true;
}
@ -324,7 +340,9 @@ public:
interval ctx, intr;
result = 0;
if (m_bound->find(t1, ctx)) {
if (b.is_full() && b.tight) {
result = m.mk_true();
} else if (m_bound.find(t1, ctx)) {
if (ctx.implies(b)) {
result = m.mk_true();
} else if (!b.intersect(ctx, intr)) {
@ -332,8 +350,6 @@ public:
} else if (m_propagate_eq && intr.is_singleton()) {
result = m.mk_eq(t1, m_bv.mk_numeral(intr.l, m.get_sort(t1)));
}
} else if (b.is_full() && b.tight) {
result = m.mk_true();
}
CTRACE("bv", result != 0, tout << mk_pp(t, m) << " " << b << " (ctx: " << ctx << ") (intr: " << intr << "): " << result << "\n";);
@ -346,36 +362,43 @@ public:
if (m_bv.is_numeral(t))
return false;
while (m.is_not(t, t));
expr_set* used_exprs = get_expr_vars(t);
for (map::iterator I = m_bound->begin(), E = m_bound->end(); I != E; ++I) {
for (map::iterator I = m_bound.begin(), E = m_bound.end(); I != E; ++I) {
if (I->m_value.is_singleton() && used_exprs->contains(I->m_key))
return true;
}
while (m.is_not(t, t));
expr* t1;
interval b;
// skip common case: single bound constraint without any context for simplification
if (is_bound(t, t1, b)) {
return m_bound->contains(t1);
return b.is_full() || m_bound.contains(t1);
}
return expr_has_bounds(t);
}
virtual void push() {
TRACE("bv", tout << "push\n";);
unsigned sz = m_scopes.size();
m_scopes.resize(sz + 1);
m_bound = &m_scopes.back();
m_bound->~map();
new (m_bound) map(m_scopes[sz - 1]);
}
virtual void pop(unsigned num_scopes) {
TRACE("bv", tout << "pop: " << num_scopes << "\n";);
m_scopes.shrink(m_scopes.size() - num_scopes);
m_bound = &m_scopes.back();
if (m_scopes.empty())
return;
unsigned target = m_scopes.size() - num_scopes;
if (target == 0) {
m_bound.reset();
m_scopes.reset();
return;
}
for (unsigned i = m_scopes.size()-1; i >= target; --i) {
undo_bound& undo = m_scopes[i];
SASSERT(m_bound.contains(undo.e));
if (undo.fresh) {
m_bound.erase(undo.e);
} else {
m_bound.insert(undo.e, undo.b);
}
}
m_scopes.shrink(target);
}
virtual simplifier * translate(ast_manager & m) {
@ -383,7 +406,7 @@ public:
}
virtual unsigned scope_level() const {
return m_scopes.size() - 1;
return m_scopes.size();
}
};

View file

@ -36,7 +36,7 @@ public:
virtual ~ctx_propagate_assertions() {}
virtual bool assert_expr(expr * t, bool sign);
virtual bool simplify(expr* t, expr_ref& result);
virtual void push();
void push();
virtual void pop(unsigned num_scopes);
virtual unsigned scope_level() const { return m_scopes.size(); }
virtual simplifier * translate(ast_manager & m);
@ -260,10 +260,6 @@ struct ctx_simplify_tactic::imp {
return m_simp->scope_level();
}
void push() {
m_simp->push();
}
void restore_cache(unsigned lvl) {
if (lvl >= m_cache_undo.size())
return;

View file

@ -31,7 +31,6 @@ public:
virtual bool assert_expr(expr * t, bool sign) = 0;
virtual bool simplify(expr* t, expr_ref& result) = 0;
virtual bool may_simplify(expr* t) { return true; }
virtual void push() = 0;
virtual void pop(unsigned num_scopes) = 0;
virtual simplifier * translate(ast_manager & m) = 0;
virtual unsigned scope_level() const = 0;