Added use_raw_nnue_eval option to return raw NNUE eval value in evaluate().

src/evaluate.cpp

@@ -32,6 +32,13 @@
 #include "thread.h"
 #include "uci.h"
 
+#ifdef EVAL_LEARN
+namespace Learner
+{
+    extern bool use_raw_nnue_eval;
+}
+#endif
+
 namespace Eval {
 
   bool useNNUE;
@@ -941,6 +948,11 @@ make_v:
 /// evaluation of the position from the point of view of the side to move.
 
 Value Eval::evaluate(const Position& pos) {
+#ifdef EVAL_LEARN
+  if (Learner::use_raw_nnue_eval) {
+      return NNUE::evaluate(pos);
+  }
+#endif
 
   if (Eval::useNNUE)
   {

src/learn/learner.cpp

@@ -133,6 +133,10 @@ double dest_score_max_value = 1.0;
 // probabilities in the trainer. Sometimes we want to use the winning probabilities in the training
 // data directly. In those cases, we set false to this variable.
 bool convert_teacher_signal_to_winning_probability = true;
+// Enable hybrid eval. If hybrid eval is enabled, training data generation and
+// training don't work well.
+// https://discordapp.com/channels/435943710472011776/733545871911813221/748524079761326192
+bool use_raw_nnue_eval = false;
 
 // -----------------------------------
 // write phase file
@@ -1050,6 +1054,8 @@ void gen_sfen(Position&, istringstream& is)
 			is >> detect_draw_by_consecutive_low_score;
 		else if (token == "detect_draw_by_insufficient_mating_material")
 			is >> detect_draw_by_insufficient_mating_material;
+		else if (token == "use_raw_nnue_eval")
+			is >> use_raw_nnue_eval;
 		else
 			cout << "Error! : Illegal token " << token << endl;
 	}
@@ -3227,6 +3233,7 @@ void learn(Position&, istringstream& is)
 		else if (option == "dest_score_min_value") is >> dest_score_min_value;
 		else if (option == "dest_score_max_value") is >> dest_score_max_value;
 		else if (option == "convert_teacher_signal_to_winning_probability") is >> convert_teacher_signal_to_winning_probability;
+		else if (option == "use_raw_nnue_eval") is >> use_raw_nnue_eval;
 
 		// Otherwise, it's a filename.
 		else