Bug fixed and clean the codes.

1. Fix the bug in DivMe function which cannot handle the scalar tensor and broadcast case.
2. Clean the codes.
3. Fix minor errors.

source/tensor/core/arithmetic/Div.cpp

@@ -146,7 +146,7 @@ void _DivMe(XTensor * a, const XTensor * b, DTYPE alpha, int leadingDim)
 element-wise division of two tensors (do it on site)
 keep the result in the input tensor a and return nothing
 
-a(i) = a(i)*b(i) + \alpha * a(i)
+a(i) = a(i)/b(i) + \alpha * a(i)
 where i is the index of the item
 
 >> a - tensor a (where keep the result)
@@ -154,9 +154,35 @@ where i is the index of the item
 >> alpha - the coefficient
 >> leadingDim - the dimension along which we perform broadcasting
 */
-void DivMe(XTensor& a, const XTensor& b, DTYPE alpha, int leadingDim)
+void DivMe(XTensor & a, const XTensor & b, DTYPE alpha, int leadingDim)
 {
-    _Div(&a, &b, &a, alpha, leadingDim);
+    if (b.order == 0){
+        DTYPE scale = 1.0F / b.Get0D();
+        XTensor * tmp1 = NewTensorBufV2(&a, a.devID, a.mem);
+        XTensor * tmp2 = NewTensorBufV2(&a, a.devID, a.mem);
+
+        _ScaleAndShift(&a, tmp1, scale, 0.0F);
+        _ScaleAndShift(&a, tmp2, alpha, 0.0F);
+        _Sum(tmp2, tmp1, &a);
+
+        DelTensorBuf(tmp1);
+        DelTensorBuf(tmp2);
+    }
+    else {
+        int n = GetBroadcastDimIndex(a, b);
+
+        if (n == -1) {
+            CheckNTErrors(a.dimSize[leadingDim] == b.dimSize[leadingDim], "TODO!");
+
+            /* call _Div function */
+            _Div(&a, &b, &a, alpha, leadingDim);
+        }
+        else if (n >= 0 && n < a.order)
+            /* call _DivDim function */
+            _DivDim(&a, &b, &a, n, alpha);
+        else
+            ShowNTErrors("Something is wrong!");
+    }
 }
 
 /*
@@ -172,7 +198,7 @@ where i is the index of the item
 >> leadingDim - the dimension along which we perform broadcasting
 << return - the product of the tensors
 */
-XTensor Div(const XTensor &a, const XTensor &b, int leadingDim)
+XTensor Div(const XTensor & a, const XTensor & b, int leadingDim)
 {
     XTensor c(&a);
     c.SetTMPFlag();
@@ -226,7 +252,7 @@ where i is the index of the item
 >> alpha - the coefficient
 >> leadingDim - the dimension along which we perform broadcasting
 */
-void Div(const XTensor &a, const XTensor &b, XTensor &c, DTYPE alpha, int leadingDim)
+void Div(const XTensor & a, const XTensor & b, XTensor & c, DTYPE alpha, int leadingDim)
 {
     if (!c.isInit || !IsSameShaped(a, c)) {
         InitTensorV2(&c, &a);