Exclude max variables from recording (follow-up from fixing preaccumulation error).

Author: oleburghardt

Common/include/basic_types/ad_structure.hpp

@@ -48,6 +48,17 @@ using Identifier = int;
  */
 inline void StartRecording() {}
 
+/*!
+ * \brief Pause the recording of the operations and involved variables.
+ * If called, all operations occuring after the call will not be stored on the computational graph.
+ */
+inline void PauseRecording() {}
+
+/*!
+ * \brief Resume the recording of the operations and variables after the recording had been paused.
+ */
+inline void ResumeRecording() {}
+
 /*!
  * \brief Stops the recording of the operations and variables.
  */
@@ -402,6 +413,10 @@ FORCEINLINE void ResetInput(su2double& data) { data = data.getValue(); }
 
 FORCEINLINE void StartRecording() { AD::getTape().setActive(); }
 
+FORCEINLINE void PauseRecording() { AD::getTape().setPassive(); }
+
+FORCEINLINE void ResumeRecording() { AD::getTape().setActive(); }
+
 FORCEINLINE void StopRecording() { AD::getTape().setPassive(); }
 
 FORCEINLINE bool TapeActive() { return AD::getTape().isActive(); }

SU2_CFD/include/solvers/CFVMFlowSolverBase.inl

@@ -673,9 +673,11 @@ void CFVMFlowSolverBase<V, R>::ComputeVorticityAndStrainMag(const CConfig& confi
     AD::SetPreaccOut(StrainMag(iPoint));
     AD::EndPreacc();
 
-    /*--- Max is not differentiable, so we not register them for preacc. ---*/
+    /*--- We don't need to record strainMax and omegaMax. ---*/
+    AD::PauseRecording();
     strainMax = max(strainMax, StrainMag(iPoint));
     omegaMax = max(omegaMax, GeometryToolbox::Norm(3, Vorticity));
+    AD::ResumeRecording();
 
   }
   END_SU2_OMP_FOR