Implemented a fallback to Gaussian elimination if Gauss-Seidel exceeds a certain number of iterations.

src/emu/netlist/analog/nld_solver.c

@@ -577,6 +577,9 @@ ATTR_HOT inline int netlist_matrix_solver_gauss_seidel_t<m_N, _storage_N>::solve
         resched_cnt++;
     } while (resched && (resched_cnt < m_resched_loops / 3 ));
 
+    if (resched)
+        return m_fallback.solve_non_dynamic();
+
     return resched_cnt;
 }
 
@@ -770,7 +773,7 @@ ATTR_COLD void NETLIB_NAME(solver)::post_start()
                 ms = new netlist_matrix_solver_direct_t<4,4>();
                 //ms = new netlist_matrix_solver_gauss_seidel_t<4,4>();
                 break;
-#if 1
+#if 0
             case 5:
                 ms = new netlist_matrix_solver_direct_t<5,5>();
                 //ms = new netlist_matrix_solver_gauss_seidel_t<4,4>();

src/emu/netlist/analog/nld_solver.h

@@ -119,15 +119,21 @@ public:
     ATTR_COLD virtual void setup(netlist_net_t::list_t &nets, NETLIB_NAME(solver) &owner)
     {
         netlist_matrix_solver_t::setup(nets, owner);
+        m_fallback.setup(nets, owner);
     }
 
     ATTR_HOT int solve_non_dynamic();
 
     ATTR_HOT inline const int N() const { if (m_N == 0) return m_nets.count(); else return m_N; }
 
-    ATTR_COLD virtual void reset() { netlist_matrix_solver_t::reset(); }
+    ATTR_COLD virtual void reset()
+    {
+        netlist_matrix_solver_t::reset();
+        m_fallback.reset();
+    }
 
 private:
+    netlist_matrix_solver_direct_t<m_N, _storage_N> m_fallback;
 };
 
 class netlist_matrix_solver_direct1_t: public netlist_matrix_solver_direct_t<1,1>

src/emu/netlist/devices/nld_legacy.c

@@ -16,8 +16,6 @@ NETLIB_START(nicRSFF)
 
 NETLIB_RESET(nicRSFF)
 {
-//    m_Q.initial(0);
-//    m_QQ.initial(1);
 }
 
 NETLIB_UPDATE(nicRSFF)

src/emu/netlist/devices/nld_system.c

@@ -51,15 +51,11 @@ NETLIB_RESET(ttl_input)
 
 NETLIB_UPDATE(ttl_input)
 {
-    //m_Q.net().m_new.Q = !(m_IN.Value() & 1);
-    //OUTLOGIC(m_Q, m_IN.Value() & 1, NLTIME_IMMEDIATE);
     OUTLOGIC(m_Q, m_IN.Value() & 1, netlist_time::from_nsec(1));
 }
 
 NETLIB_UPDATE_PARAM(ttl_input)
 {
-    //m_Q.net().m_new.Q = !(m_IN.Value() & 1);
-	//OUTLOGIC(m_Q, m_IN.Value() & 1, NLTIME_IMMEDIATE);
 }
 
 // ----------------------------------------------------------------------------------------
@@ -83,5 +79,4 @@ NETLIB_UPDATE(analog_input)
 
 NETLIB_UPDATE_PARAM(analog_input)
 {
-    //OUTANALOG(m_Q, m_IN.Value(), NLTIME_IMMEDIATE);
 }

src/emu/netlist/devices/nld_system.h

@@ -98,7 +98,6 @@ protected:
 
     ATTR_COLD void reset()
     {
-        //m_Q.initial(0.001); // Make sure update outputs something
     }
 
     ATTR_HOT ATTR_ALIGN void update()

src/emu/netlist/nl_base.c

@@ -435,7 +435,6 @@ ATTR_COLD netlist_net_t::netlist_net_t(const type_t atype, const family_t afamil
 	, m_in_queue(2)
 	, m_railterminal(NULL)
 {
-    //m_last.Analog = -123456789.0; // set to something we will never hit.
     m_last.Analog = 0.0; // set to something we will never hit.
     m_new.Analog = 0.0;
     m_cur.Analog = 0.0;
@@ -443,7 +442,6 @@ ATTR_COLD netlist_net_t::netlist_net_t(const type_t atype, const family_t afamil
 
 ATTR_COLD void netlist_net_t::reset()
 {
-    //m_last.Analog = -123456789.0; // set to something we will never hit.
     m_last.Analog = 0.0; // set to something we will never hit.
     m_cur.Analog = 0.0;
     m_last.Q = 0; // set to something we will never hit.