[NF] Improve simplification of functions.

- Evaluate constants and simplify functions during collection, to make
  sure all collected functions are processed correctly.

Belonging to [master]:
  - #2777

Author: perost

Compiler/NFFrontEnd/NFEvalConstants.mo

@@ -167,7 +167,6 @@ algorithm
       algorithm
         (outExp, outChanged) := Expression.mapFoldShallow(exp,
           function evaluateExpTraverser(isExternalArg = Call.isExternal(exp.call)), false);
-        evaluateFunction(Call.typedFunction(exp.call));
       then
         outExp;
 
@@ -443,12 +442,6 @@ algorithm
       then
         outExp;
 
-    case Expression.CALL()
-      algorithm
-        evaluateFunction(Call.typedFunction(e.call));
-      then
-        e;
-
     else if outChanged then Expression.retype(e) else e;
   end match;
 

Compiler/NFFrontEnd/NFFlatten.mo

@@ -86,6 +86,8 @@ import Ceval = NFCeval;
 import NFTyping.ExpOrigin;
 import SimplifyExp = NFSimplifyExp;
 import Restriction = NFRestriction;
+import EvalConstants = NFEvalConstants;
+import SimplifyModel = NFSimplifyModel;
 
 public
 type FunctionTree = FunctionTreeImpl.Tree;
@@ -1505,6 +1507,8 @@ function flattenFunction
   input output FunctionTree funcs;
 algorithm
   if not Function.isCollected(fn) then
+    EvalConstants.evaluateFunction(fn);
+    SimplifyModel.simplifyFunction(fn);
     Function.collect(fn);
 
     if not InstNode.isPartial(fn.node) then

Compiler/NFFrontEnd/NFFunction.mo

@@ -491,7 +491,7 @@ uniontype Function
     input Function fn;
   algorithm
     if Pointer.access(fn.status) <> FunctionStatus.BUILTIN then
-      Pointer.update(fn.status, FunctionStatus.COLLECTED);
+      Pointer.update(fn.status, FunctionStatus.SIMPLIFIED);
     end if;
   end markSimplified;
 

Compiler/NFFrontEnd/NFInst.mo

@@ -157,8 +157,6 @@ algorithm
   flat_model := EvalConstants.evaluate(flat_model);
   flat_model := SimplifyModel.simplify(flat_model);
   funcs := Flatten.collectFunctions(flat_model, name);
-  funcs := FunctionTree.map(funcs, SimplifyModel.simplifyFunction);
-  execStat("SimplifyModel.simplifyFunction");
 
   // Collect package constants that couldn't be substituted with their values
   // (e.g. because they where used with non-constant subscripts), and add them

Compiler/NFFrontEnd/NFSimplifyModel.mo

@@ -450,8 +450,7 @@ algorithm
 end simplifyIfStmtBranches;
 
 function simplifyFunction
-  input Absyn.Path name;
-  input output Function func;
+  input Function func;
 protected
   Class cls;
   Algorithm fn_body;
@@ -485,7 +484,7 @@ algorithm
 
     for fn_der in func.derivatives loop
       for der_fn in Function.getCachedFuncs(fn_der.derivativeFn) loop
-        simplifyFunction(Function.name(der_fn), der_fn);
+        simplifyFunction(der_fn);
       end for;
     end for;
   end if;