- When doing static scheduling, filter out empty systems

- When creating the loop for equation systems to solve, if size=0 or 1, unroll the loop


git-svn-id: https://openmodelica.org/svn/OpenModelica/trunk@15444 f25d12d1-65f4-0310-ae8a-bbce733d8d8e

Compiler/BackEnd/SimCodeUtil.mo

@@ -1609,6 +1609,9 @@ algorithm
 
       odeEquations = makeEqualLengthLists(odeEquations, Config.noProc());
       algebraicEquations = makeEqualLengthLists(algebraicEquations, Config.noProc());
+      /* Filter out empty systems to improve code generation */
+      odeEquations = List.filterOnTrue(odeEquations, List.isNotEmpty);
+      algebraicEquations = List.filterOnTrue(algebraicEquations, List.isNotEmpty);
 
       Debug.fcall(Flags.EXEC_HASH, print, "*** SimCode -> generate cref2simVar hastable: " +& realString(clock()) +& "\n");
       crefToSimVarHT = createCrefToSimVarHT(modelInfo);

Compiler/Template/CodegenC.tpl

@@ -1520,11 +1520,16 @@ template functionXXX_systems(list<list<SimEqSystem>> eqs, String name, Text &loo
   let funcs = eqs |> eq hasindex i1 fromindex 0 => functionXXX_system(eq,name,i1) ; separator="\n"
   let nFuncs = listLength(eqs)
   let funcNames = eqs |> e hasindex i1 fromindex 0 => 'function<%name%>_system<%i1%>' ; separator=",\n"
+  let head = if Flags.isSet(Flags.OPENMP) then '#pragma omp parallel for private(id,th_id) schedule(<%match noProc() case 0 then "dynamic" else "static"%>)'
   let &varDecls += 'int id, th_id;<%\n%>'
   let &loop +=
   /* Text for the loop body that calls the equations */
+  match listLength(eqs)
+  case 0 then ""
+  case 1 then 'function<%name%>_systems[0](data,omp_get_thread_num());'
+  else
   <<
-  <% if Flags.isSet(Flags.OPENMP) then '#pragma omp parallel for private(id,th_id) schedule(<%match noProc() case 0 then "dynamic" else "static"%>)' %>
+  <%head%>
   for(id=0; id<<%nFuncs%>; id++) {
     th_id = omp_get_thread_num();
     function<%name%>_systems[id](data,th_id);