[NB] adding simplification of when conditions (#11858)

- adding CombiTimeTable test (not yet running)

OMCompiler/Compiler/NBackEnd/Classes/NBEquation.mo

@@ -1283,7 +1283,9 @@ public
         case ALGORITHM()       then eq;
         case IF_EQUATION()     then eq;
         case FOR_EQUATION()    then eq;
-        case WHEN_EQUATION()   then eq;
+        case WHEN_EQUATION() algorithm
+          eq.body := WhenEquationBody.simplify(eq.body, name, indent);
+        then eq;
         case AUX_EQUATION()    then eq;
         else algorithm
           Error.addMessage(Error.INTERNAL_ERROR,{getInstanceName() + " failed for: " + Equation.toString(eq)});
@@ -2467,6 +2469,29 @@ public
       bodies := listReverse(bodies);
     end split;
 
+    function simplify
+      input output WhenEquationBody body;
+      input String name = "";
+      input String indent = "";
+    algorithm
+      // simplify condition if it is an array with surplus false conditions
+      body.condition := match body.condition
+        local
+          Expression condition;
+          list<Expression> conditions;
+        case condition as Expression.ARRAY() algorithm
+          conditions := list(elem for elem guard(not Expression.isFalse(elem)) in arrayList(condition.elements));
+          body.condition := Expression.makeArrayCheckLiteral(Type.ARRAY(Type.BOOLEAN(), {Dimension.fromInteger(listLength(conditions))}), listArray(conditions));
+        then body.condition;
+        else body.condition;
+      end match;
+
+      // ToDo: add simplification of body! (WhenStatements)
+
+      body.condition := SimplifyExp.simplifyDump(body.condition, true, name, indent);
+      body.else_when := Util.applyOption(body.else_when, function simplify(name = name, indent = indent));
+    end simplify;
+
   protected
     function collectForSplit
       "collects all discrete states and regular states for splitting up

testsuite/simulation/modelica/NBackend/ScalableTestsuite/CombiTimeTable.mos

@@ -0,0 +1,27 @@
+// name: ScalableTestSuite.Elementary.Tables.Models.CombiTimeTable
+// keywords: NewBackend
+// status: correct
+// cflags: --newBackend
+
+loadModel(ScalableTestSuite); getErrorString();
+
+simulate(ScalableTestSuite.Elementary.Tables.Models.CombiTimeTable); getErrorString();
+
+res := OpenModelica.Scripting.compareSimulationResults("ScalableTestSuite.Elementary.Tables.Models.CombiTimeTable_res.mat",
+  "ReferenceFiles/ScalableTestSuite.Elementary.Tables.Models.CombiTimeTable_res.mat",
+  "ScalableTestSuite.Elementary.Tables.Models.CombiTimeTable_diff.csv",0.01,0.0001,
+  {"combiTimeTable.y[1]"});
+
+// Result:
+// true
+// ""
+// record SimulationResult
+//     resultFile = "ScalableTestSuite.Elementary.Tables.Models.CombiTimeTable_res.mat",
+//     simulationOptions = "startTime = 0.0, stopTime = 1.0, numberOfIntervals = 1, tolerance = 1e-6, method = 'dassl', fileNamePrefix = 'ScalableTestSuite.Elementary.Tables.Models.CombiTimeTable', options = '', outputFormat = 'mat', variableFilter = '.*', cflags = '', simflags = ''",
+//     messages = "LOG_SUCCESS       | info    | The initialization finished successfully without homotopy method.
+// LOG_SUCCESS       | info    | The simulation finished successfully.
+// "
+// end SimulationResult;
+// ""
+// {"Files Equal!"}
+// endResult

testsuite/simulation/modelica/NBackend/ScalableTestsuite/Makefile

@@ -27,6 +27,7 @@ SimpleAdvection.mos \
 # test that currently fail. Move up when fixed.
 # Run make failingtest
 FAILINGTESTFILES = \
+CombiTimeTable.mos \
 TransmissionLineEquations.mos \
 
 # Dependency files that are not .mo .mos or Makefile