add stats for throttling

src/math/lp/lp_settings.h

@@ -136,6 +136,7 @@ struct statistics {
     unsigned m_dio_rewrite_conflicts = 0;
     unsigned m_bounds_tightening_conflicts = 0;
     unsigned m_bounds_tightenings = 0;
+    unsigned m_nla_throttled_lemmas = 0;
     ::statistics m_st = {};
 
     void reset() {
@@ -173,6 +174,7 @@ struct statistics {
         st.update("arith-dio-rewrite-conflicts", m_dio_rewrite_conflicts);
         st.update("arith-bounds-tightening-conflicts", m_bounds_tightening_conflicts);
         st.update("arith-bounds-tightenings", m_bounds_tightenings);
+        st.update("arith-nla-throttled-lemmas", m_nla_throttled_lemmas);
         st.copy(m_st);
     }
 };

src/math/lp/nla_core.cpp

@@ -39,7 +39,8 @@ core::core(lp::lar_solver& s, params_ref const& p, reslimit & lim) :
     m_emons(m_evars),
     m_use_nra_model(false),
     m_nra(s, m_nra_lim, *this),
-    m_throttle(lra.trail()) {
+    m_throttle(lra.trail(), 
+	lra.settings().stats()) {
      m_nlsat_delay_bound = lp_settings().nlsat_delay();
      m_throttle.set_enabled(m_params.arith_nl_thrl());
      lra.m_find_monics_with_changed_bounds_func = [&](const indexed_uint_set& columns_with_changed_bounds) {

src/math/lp/nla_throttle.cpp

@@ -76,6 +76,7 @@ bool nla_throttle::insert_new(throttle_kind k, lpvar monic_var, lpvar x_var, lpv
 bool nla_throttle::insert_new_impl(const signature& sig) {
     if (m_seen.contains(sig)) {
         TRACE(nla_solver, tout << "throttled lemma generation\n";);
+        m_stats.m_nla_throttled_lemmas++;
         return true;  // Already seen, throttle
     }
     

src/math/lp/nla_throttle.h

@@ -7,6 +7,7 @@
   --*/
 #pragma once
 #include "math/lp/nla_defs.h"
+#include "math/lp/lp_settings.h"
 #include "util/hashtable.h"
 #include "util/trail.h"
 #include <cstring>
@@ -47,10 +48,11 @@ private:
     
     hashtable<signature, signature_hash, default_eq<signature>> m_seen;
     trail_stack& m_trail;
+    lp::statistics& m_stats;
     bool m_enabled = true;
     
 public:
-    nla_throttle(trail_stack& trail) : m_trail(trail) {}
+    nla_throttle(trail_stack& trail, lp::statistics& stats) : m_trail(trail), m_stats(stats) {}
       void set_enabled(bool enabled) { m_enabled = enabled; }
     bool enabled() const { return m_enabled; }