Minor optimizations on MooseVariableData

framework/include/utils/MooseTypes.h

@@ -581,7 +581,7 @@ struct IsADType<MetaPhysicL::DualNumber<T, Args...>>
  * error with constexpr-based if conditions. The templating delays the triggering
  * of the static assertion until the template is instantiated.
  */
-template <class T>
+template <class... Ts>
 constexpr std::false_type always_false{};
 
 } // namespace Moose

framework/include/variables/MooseVariableData.h

@@ -461,6 +461,15 @@ class MooseVariableData : public MooseVariableDataBase<OutputType>
   void assignADNodalValue(const ADReal & value, const unsigned int & component);
   void fetchADNodalValues();
 
+  /**
+   * Internal method for computeValues() and computeMonomialValues()
+   *
+   * Monomial is a template parameter so that we get compile time optimization
+   * for monomial vs non-monomial
+   */
+  template <bool monomial>
+  void computeValuesInternal();
+
   const libMesh::FEType & _fe_type;
 
   const unsigned int _var_num;
@@ -554,19 +563,19 @@ class MooseVariableData : public MooseVariableDataBase<OutputType>
   FieldVariableValue _u_dot;
 
   /// u_dotdot (second time derivative)
-  FieldVariableValue _u_dotdot, _u_dotdot_bak;
+  FieldVariableValue _u_dotdot;
 
   /// u_dot_old (time derivative)
-  FieldVariableValue _u_dot_old, _u_dot_old_bak;
+  FieldVariableValue _u_dot_old;
 
   /// u_dotdot_old (second time derivative)
-  FieldVariableValue _u_dotdot_old, _u_dotdot_old_bak;
+  FieldVariableValue _u_dotdot_old;
 
   /// derivative of u_dot wrt u
   VariableValue _du_dot_du;
 
   /// derivative of u_dotdot wrt u
-  VariableValue _du_dotdot_du, _du_dotdot_du_bak;
+  VariableValue _du_dotdot_du;
 
   /// The current qrule. This has to be a reference because the current qrule will be constantly
   /// changing. If we initialized this to point to one qrule, then in the next calculation we would

framework/include/variables/MooseVariableDataFV.h

@@ -373,19 +373,19 @@ class MooseVariableDataFV : public MooseVariableDataBase<OutputType>, public Mes
   FieldVariableValue _u_dot;
 
   /// u_dotdot (second time derivative)
-  FieldVariableValue _u_dotdot, _u_dotdot_bak;
+  FieldVariableValue _u_dotdot;
 
   /// u_dot_old (time derivative)
-  FieldVariableValue _u_dot_old, _u_dot_old_bak;
+  FieldVariableValue _u_dot_old;
 
   /// u_dotdot_old (second time derivative)
-  FieldVariableValue _u_dotdot_old, _u_dotdot_old_bak;
+  FieldVariableValue _u_dotdot_old;
 
   /// derivative of u_dot wrt u
   VariableValue _du_dot_du;
 
   /// derivative of u_dotdot wrt u
-  VariableValue _du_dotdot_du, _du_dotdot_du_bak;
+  VariableValue _du_dotdot_du;
 
   /// Pointer to time integrator
   const TimeIntegrator * const _time_integrator;

framework/src/variables/MooseVariableConstMonomial.C

@@ -42,50 +42,26 @@ void
 MooseVariableConstMonomial::computeElemValues()
 {
   _element_data->setGeometry(Moose::Volume);
-
-  // We have not optimized AD calculations for const monomials yet, so we fall back on the
-  // non-optimized routine
-  if (_element_data->needsAD())
-    _element_data->computeValues();
-  else
-    _element_data->computeMonomialValues();
+  _element_data->computeMonomialValues();
 }
 
 void
 MooseVariableConstMonomial::computeElemValuesFace()
 {
   _element_data->setGeometry(Moose::Face);
-
-  // We have not optimized AD calculations for const monomials yet, so we fall back on the
-  // non-optimized routine
-  if (_element_data->needsAD())
-    _element_data->computeValues();
-  else
-    _element_data->computeMonomialValues();
+  _element_data->computeMonomialValues();
 }
 
 void
 MooseVariableConstMonomial::computeNeighborValues()
 {
   _neighbor_data->setGeometry(Moose::Volume);
-
-  // We have not optimized AD calculations for const monomials yet, so we fall back on the
-  // non-optimized routine
-  if (_neighbor_data->needsAD())
-    _neighbor_data->computeValues();
-  else
-    _neighbor_data->computeMonomialValues();
+  _neighbor_data->computeMonomialValues();
 }
 
 void
 MooseVariableConstMonomial::computeNeighborValuesFace()
 {
   _neighbor_data->setGeometry(Moose::Face);
-
-  // We have not optimized AD calculations for const monomials yet, so we fall back on the
-  // non-optimized routine
-  if (_neighbor_data->needsAD())
-    _neighbor_data->computeValues();
-  else
-    _neighbor_data->computeMonomialValues();
+  _neighbor_data->computeMonomialValues();
 }