running updates to bv_solver (#4674)

* na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * dbg Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * bv Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * drat and fresh Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * move ackerman functionality Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * debugability Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * towards debugability Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * missing file Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * na Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com> * remove csp Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
2025-04-28 11:25:51 +00:00 · 2020-09-07 20:35:32 -07:00 · 2020-09-07 20:35:32 -07:00 · d02b0cde7a
commit d02b0cde7a
parent 4d1a2a2784
63 changed files with 3060 additions and 3095 deletions
--- a/src/sat/smt/bv_ackerman.cpp
+++ b/src/sat/smt/bv_ackerman.cpp
@ -0,0 +1,153 @@
+/*++
+Copyright (c) 2020 Microsoft Corporation
+
+Module Name:
+
+    bv_ackerman.cpp
+
+Abstract:
+
+    Ackerman reduction plugin for bit-vectors
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2020-08-28
+
+--*/
+
+#include "sat/smt/bv_solver.h"
+#include "sat/smt/bv_ackerman.h"
+
+namespace bv {
+
+    ackerman::ackerman(solver& s): s(s) {
+        new_tmp();
+        m_propagate_low_watermark = s.get_config().m_dack_threshold;
+    }
+
+    ackerman::~ackerman() {
+        reset();
+        dealloc(m_tmp_vv);
+    }
+
+    void ackerman::reset() {
+        m_table.reset();
+        m_queue = nullptr;        
+    }
+
+    void ackerman::used_eq_eh(euf::theory_var v1, euf::theory_var v2) {
+        if (v1 == v2)
+            return;
+        if (v1 > v2)
+            std::swap(v1, v2);
+        vv* n = m_tmp_vv;
+        n->v1 = v1;
+        n->v2 = v2;
+        vv* other = m_table.insert_if_not_there(n);        
+        other->m_count++;
+        update_glue(*other);
+        if (other->m_count > m_propagate_high_watermark || other->m_glue == 0)
+            s.s().set_should_simplify();
+        vv::push_to_front(m_queue, other);
+        if (other == n) {
+            new_tmp();        
+            gc();
+        }
+    }
+
+    void ackerman::update_glue(vv& v) {
+        unsigned sz = s.m_bits[v.v1].size();
+        m_diff_levels.reserve(s.s().scope_lvl() + 1, false);
+        unsigned glue = 0;
+        unsigned max_glue = v.m_glue;
+        auto const& bitsa = s.m_bits[v.v1];
+        auto const& bitsb = s.m_bits[v.v2];
+        unsigned i = 0;
+        for (; i < sz && i < max_glue; ++i) {
+            sat::literal a = bitsa[i];
+            sat::literal b = bitsb[i];
+            if (a == b)
+                continue;
+            SASSERT(s.s().value(a) != l_undef);
+            SASSERT(s.s().value(b) == s.s().value(a));
+            unsigned lvl_a = s.s().lvl(a);
+            unsigned lvl_b = s.s().lvl(b);
+            if (!m_diff_levels[lvl_a]) {
+                m_diff_levels[lvl_a] = true;
+                ++glue;
+            }
+            if (!m_diff_levels[lvl_b]) {
+                m_diff_levels[lvl_b] = true;
+                ++glue;
+            }            
+        }
+        for (; i-- > 0; ) {
+            sat::literal a = bitsa[i];
+            sat::literal b = bitsb[i];
+            if (a != b) {
+                m_diff_levels[s.s().lvl(a)] = false;
+                m_diff_levels[s.s().lvl(b)] = false;
+            }
+        }
+        
+        if (glue < max_glue) 
+            v.m_glue = glue <= sz ? 0 : glue;
+    }
+
+    void ackerman::remove(vv* p) {
+        vv::remove_from(m_queue, p);
+        m_table.erase(p);
+        dealloc(p);
+    }
+
+    void ackerman::new_tmp() {
+        m_tmp_vv = alloc(vv);
+        m_tmp_vv->init(m_tmp_vv);
+        m_tmp_vv->m_count = 0;
+        m_tmp_vv->m_glue = UINT_MAX;
+    }
+        
+    void ackerman::gc() {
+        m_num_propagations_since_last_gc++;
+        if (m_num_propagations_since_last_gc <= s.get_config().m_dack_gc) 
+            return;
+        m_num_propagations_since_last_gc = 0;
+        
+        while (m_table.size() > m_gc_threshold) 
+            remove(m_queue->prev());     
+
+        m_gc_threshold *= 110;
+        m_gc_threshold /= 100;
+        m_gc_threshold++;
+    }
+
+    void ackerman::propagate() {
+        SASSERT(s.s().at_base_lvl());
+        auto* n = m_queue;
+        vv* k = nullptr;
+        unsigned num_prop = static_cast<unsigned>(s.s().get_stats().m_conflict * s.get_config().m_dack_factor);
+        num_prop = std::min(num_prop, m_table.size());
+        for (unsigned i = 0; i < num_prop; ++i, n = k) {
+            k = n->next();
+            if (n->m_count < m_propagate_low_watermark && n->m_glue != 0)
+                continue;            
+            add_cc(n->v1, n->v2);
+            remove(n);
+        }
+    }
+
+    void ackerman::add_cc(euf::theory_var v1, euf::theory_var v2) {
+        SASSERT(v1 < v2);
+        if (static_cast<unsigned>(v2) >= s.get_num_vars())
+            return;
+        if (!s.var2enode(v1) || !s.var2enode(v2))
+            return;
+        sort* s1 = s.m.get_sort(s.var2expr(v1));
+        sort* s2 = s.m.get_sort(s.var2expr(v2));
+        if (s1 != s2 || !s.bv.is_bv_sort(s1))
+            return;
+        IF_VERBOSE(0, verbose_stream() << "assert ackerman " << v1 << " " << v2 << "\n");
+        s.assert_ackerman(v1, v2);
+    }
+
+}