Bug fixed.

source/tensor/XCall.h

@@ -27,7 +27,7 @@
 namespace nts { // namespace nts(NiuTrans.Tensor)
 namespace nts { // namespace nts(NiuTrans.Tensor)
 
 
 /* default settings */
 /* default settings */
-#define X_ENABLE_GRAD false
+#define X_ENABLE_GRAD true
 
 
 /*
 /*
 * we define the "new and delete" functions below
 * we define the "new and delete" functions below