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add tuned implementation

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2019-12-19 15:26:55 -08:00
parent 78b022491d
commit 6ad55cc8f6
4 changed files with 230 additions and 23 deletions
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39
src/math/dd/dd_pdd.cpp
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@ -362,6 +362,13 @@ namespace dd {
}
}
// a = s*x + t, where s is a constant, b = u*x + v, where u is a constant.
// since x is the maximal variable, it does not occur in t or v.
// thus, both a and b are linear in x
bool pdd_manager::spoly_is_invertible(pdd const& a, pdd const& b) {
return a.is_var() && b.is_var() && a.hi().is_val() && b.hi().is_val() && a.var() == b.var();
}
/*
* Compare leading monomials.
* The pdd format makes lexicographic comparison easy: compare based on
@ -609,6 +616,38 @@ namespace dd {
return m_tree_size[p.root];
}
unsigned_vector const& pdd_manager::free_vars(pdd const& p) {
return free_vars_except(p, zero());
}
unsigned_vector const& pdd_manager::free_vars_except(pdd const& p, pdd const& q) {
init_mark();
m_free_vars.reset();
m_todo.push_back(q.root);
while (!m_todo.empty()) {
PDD r = m_todo.back();
m_todo.pop_back();
if (is_val(r) || is_marked(r)) continue;
set_mark(r);
set_mark(m_var2pdd[var(r)]);
if (!is_marked(lo(r))) m_todo.push_back(lo(r));
if (!is_marked(hi(r))) m_todo.push_back(hi(r));
}
m_todo.push_back(p.root);
while (!m_todo.empty()) {
PDD r = m_todo.back();
m_todo.pop_back();
if (is_val(r) || is_marked(r)) continue;
PDD v = m_var2pdd[var(r)];
if (!is_marked(v)) m_free_vars.push_back(var(r));
set_mark(r);
set_mark(v);
if (!is_marked(lo(r))) m_todo.push_back(lo(r));
if (!is_marked(hi(r))) m_todo.push_back(hi(r));
}
return m_free_vars;
}
void pdd_manager::alloc_free_nodes(unsigned n) {
for (unsigned i = 0; i < n; ++i) {