revert optimizing the division code for evaluations

bin/genEvalSpecializations.py

@@ -319,23 +319,23 @@ public:
     // m(u*v)' = (vu' - uv')/v^2
     Evaluation& operator/=(const Evaluation& other)
     {
-        // values are divided, derivatives follow the rule for division, i.e., (u/v)' = (v'u - u'v)/v^2.
-        const ValueType v_vv = 1.0 / other.value();
-        const ValueType u_vv = value() * v_vv * v_vv;
-
-        // value
-        data_[valuepos_] *= v_vv;
-
-        //  derivatives
+        // values are divided, derivatives follow the rule for division, i.e., (u/v)' = (v'u -
+        // u'v)/v^2.
+        ValueType& u = data_[ valuepos_ ];
+        const ValueType& v = other.value();
 {% if numDerivs < 0 %}\
-        for (int i = dstart_; i < dend_; ++i) {
-            data_[i] = data_[i] * v_vv - other.data_[i] * u_vv;
+        for (unsigned idx = dstart_; idx < dend_; ++idx) {
+            const ValueType& uPrime = data_[idx];
+            const ValueType& vPrime = other.data_[idx];
+
+            data_[idx] = (v*uPrime - u*vPrime)/(v*v);
         }
 {% else %}\
 {%   for i in range(1, numDerivs+1) %}\
-        data_[{{i}}] = data_[{{i}}] * v_vv - other.data_[{{i}}] * u_vv;
+        data_[{{i}}] = (v*data_[{{i}}] - u*other.data_[{{i}}])/(v*v);
 {%   endfor %}\
 {% endif %}\
+        u /= v;
 
         return *this;
     }
@@ -359,29 +359,6 @@ public:
         return *this;
     }
 
-    // division of a constant by an Evaluation
-    template <class RhsValueType>
-    static inline Evaluation divide(const RhsValueType& a, const Evaluation& b)
-    {
-        Evaluation result;
-
-        const ValueType tmp = 1.0/b.value();
-        result.setValue( a*tmp );
-        const ValueType df_dg = - result.value()*tmp;
-
-{% if numDerivs < 0 %}\
-        for (int i = dstart_; i < dend_; ++i) {
-            result.data_[i] = df_dg * b.data_[i];
-        }
-{% else %}\
-{%   for i in range(1, numDerivs+1) %}\
-        result.data_[{{i}}] = df_dg * b.data_[{{i}}];
-{%   endfor %}\
-{% endif %}\
-
-        return result;
-    }
-
     // add two evaluation objects
     Evaluation operator+(const Evaluation& other) const
     {
@@ -621,7 +598,9 @@ Evaluation<ValueType, numVars> operator-(const RhsValueType& a, const Evaluation
 template <class RhsValueType, class ValueType, int numVars>
 Evaluation<ValueType, numVars> operator/(const RhsValueType& a, const Evaluation<ValueType, numVars>& b)
 {
-    return Evaluation<ValueType, numVars>::divide(a, b);
+    Evaluation<ValueType, numVars> tmp(a);
+    tmp /= b;
+    return tmp;
 }
 
 template <class RhsValueType, class ValueType, int numVars>